强脉冲噪声暴露后大鼠听皮层蛋白质差异表达的研究

目的 运用蛋白质组学技术检测强脉冲噪声暴露后不同时间点大鼠听皮层蛋白质表达谱的差异.方法 健康成年SD大鼠分为三组:正常对照组、急性脉冲噪声暴露组及噪声暴露后恢复组.脉冲噪声平均压力峰值(声压级)为156 dB,脉宽为0.25 ms,暴露50次.听性脑干反应(ABR)评价大鼠听功能;运用二维凝胶电泳+质谱分析法对各组大鼠听皮层蛋白质表达谱进行检测,比较其差异,并对表达变化较大的蛋白进行质谱鉴定.结果 与对照组相比,急性暴露组及恢复组在ABR各频率(2、4、8、16、32 kHz)阈值均明显提高(P值均＜0.05);噪声暴露即刻,ABR各频率听阈均有40 ～60 dB的上升;暴露后第7天,各频率ABR阈值有所恢复,第14天时趋于稳定.噪声暴露前后听皮层组织中的差异蛋白有64个,选取变化倍数大的50个点进行酶切质谱鉴定.其中有14个点不可信,剩余36个点所代表的27种蛋白被鉴定出来.所鉴定的差异蛋白主要包括:细胞骨架相关蛋白,线粒体及能量代谢相关蛋白,与突触重塑、神经递质释放及神经元兴奋性相关的蛋白等.结论 强脉冲噪声暴露可引起大鼠听皮层中多种蛋白质表达的变化,这些差异蛋白可能参与强噪声听力损伤的修复过程,以及听觉中枢的可塑性变化及功能重组.

Study on discrepant protein expression in rat auditory cortex under impulse noise exposure

Objective Impulse noise was adopted in adult rats to built acute deafferent animal model.Differential proteomics techniques were applied to detect the changes of protein expression in the auditory cortex before and after the noise exposure.Methods Thirty adult SD rats were divided into three groups:normal group,rats with acute noise exposure and rats 28 days recovery after noise exposure (n =10/group).All animals were exposed to impulse noise at 156 dB for 50 pulses with a rise-time of 100 μs and duration of around 0.25 ms.ABR was used to evaluate the auditory function.The two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF-MS) were used to identified the differential protein expression.Results Compared with the normal group,ABR thresholds were found significantly increased at 2,4,8,16,32 kHz(P ＜0.05) in the acute and recovery groups.There was a 40 - 60 dBSPL ABR threshold shift at all tested frequencies immediately after impulse noise exposure.There was a partial recovery of ABR thresholds at 7 day to 28 days after impulse noise exposure.In addition,it seemed that the thresholds were rather stable and no further ABR threshold recovery was observed from 14 day to 28 days after the impulse noise exposure.Using differential proteomic techniques,36 spots containing 27 proteins were revealed and identified in auditory cortex.Those proteins are related to cytoskeleton,neurotransmission,energy supply,mitochondrial function and synaptic remolding.Conclusions Impulse noise may influence the function of microtubule transport and cell metabolism,there after affect the neurotransmission of auditory neurons.The compensatory changes such as pre- and postsynaptic or such related functional changes may also happen in auditory cortex after the deafferentation treatment.