miR-183家族在噪声性聋发生发展中的表达及研究

The expression of miR-183 family in the pathogenesis and development of noise-induced deafness

目的：建立噪声性聋动物模型,并检测不同时间段耳蜗内MicroRNA183家族成员表达量的变化,为探索噪声性聋相关的发病机制提供思路。方法：50只小鼠随机分为5个组（1、7、14、28d实验组及对照组）,每组10只。实验组给予中心频率2.0~4.0kHz的窄带噪声,强度为100dB SPL,每天6h,持续3d;对照组不接触噪声。在噪声刺激前及刺激后1、7、14和28d后分别测得ABR阈值。通过耳蜗基膜铺片来检测毛细胞的病理损伤过程,并采用实时定量聚合酶链反应（qRT-PCR）检测MicroRNA183家族成员表达量的变化。采用SPSS17.0软件对数据进行统计学分析。结果：噪声刺激后,各实验组听力与刺激前及对照组相比均明显下降（均P〈0.01）;1d组较其他实验组下降更明显（P〈0.01）,7d组次之（P〈0.05）;14d与28d组间听力下降程度相近,差异无统计学意义（P〉0.05）。铺片检测发现随着时间的延长,外毛细胞排列发生混乱、变形以及缺损数量逐渐增加,且多集中在第1和第2排,内毛细胞未见明显缺失。qRT-PCR检测显示：噪声刺激后1d和7d组miR-183/96/182的表达量均较对照组下降（均P〈0.01）,而1d与7d组间差异无统计学意义（P〉0.05）;14d组的表达量呈明显上升趋势（P〈0.01）;28d组表达量较14d组明显回降（P〈0.01）,但仍高于1d组和7d组（P〈0.01）。结论：MicroRNA183家族成员在噪声刺激后的一段时间内表达量存在着显著变化,可能作为特异性基因在噪声性聋发生发展中起着重要作用。

Objective：To detect the expression variation of microRNA-183family in cochlea of animal model characterized by noise-induced deafness at various time points,and to explore the mechanisms responsible for noise-induced deafness.Method：Fifty mice were randomly divided into 5groups.In the experimental group,40 mice were exposed to 2-4kHz narrow band noise at 100dB SPL 6hper day for 3consecutive days.The rest 10 mice served as the control group without receiving any noise.Auditory brainsterm response（ABR）were examined at the 1st,7th,14th and 28th day compaired with the ABR before the experiment,to confirm noise lead to the permanent threshold shift.The pathological damage processes of hair cell were detected by the basilar membrane stretched techniques.Real-time reverse transcriptase-polymerase chain reaction（qRT-PCR）was apply to quantify the expression of microRNA183family members.Statistical analysis was performed by the SPSS 17.0software. Result：The hearing of mice in the experimental group was significantly less than that in the control group.In the experimental group,the hearing of mice exposed to noise were markedly less when compared with the one exposure to null-noise.The hearing in the 1st day group was least among experimental groups,and the followed one was mice in the 7th day group.No statistical difference were observed between the 14th and 28th day groups（P〈0.05）.The results of surface preparation showed that the outer hair cells were chaotic,deformational,and their number decreased is time-dependent.The missing of the outer hair cells occurred mainly in the first and second rows,while the inner hair cells were not pronouncedly missing.The qRT-PCR showed that the expressions of the three genes（miR-183/96/182）in the 1st day and 7th day group with exposure to noise were less than in the control group（P〈0.01）,while no significant difference was found between 1st day and 7th day group（P〈0.05）.The expressions rised in the 14th day experimental groups,whereas the 28th day group＇sexpressions of the three genes decreased markedly which were more than that in the 1st day and 7th day group（P〈0.01）.Conclusion：After noise exposure for some time,the expressions of miRNA-183family members have significant changes in animal model with noise-induced deafness,which indicated that the miRNA183family members may play important roles in the pathogenesis and development of noise-induced deafness.