Noise overstimulation induces immediate early genes in the rat cochlea
Noise overstimulation induces immediate early genes in the rat cochlea
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DOI：
10.1016/j.molbrainres.2004.07.017
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发表时间：
2004-11-04
期刊：
影响因子：
--
通讯作者：
Lomax, MI
中科院分区：
文献类型：
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作者：
Cho, YS;Gong, TWL;Lomax, MI
在哺乳动物中，暴露于强噪声会产生永久性听力损失，称为永久性阈值偏移（PTS），而中等噪声仅产生暂时性阈值偏移（TTS）。人们对这种高强度噪声暴露的分子反应知之甚少。在这项研究中，我们使用基因阵列来研究大鼠耳蜗对声过度刺激的早期反应。我们比较了来自噪声暴露大鼠的耳蜗RNA与来自未暴露对照的RNA。强PTS噪声诱导了编码转录因子（c-FOS、EGRI、TR 77/TR 3）和细胞因子（PC 3/BTG 2、LIF和IP 10）的几个立即早期基因。相反，TTS噪音下调了生长激素基因。在90 min噪声暴露后2.5 h，用定量RT-PCR方法检测这些基因对不同噪声强度的反应。对于大多数基因，诱导的程度与噪音暴露的强度相关。在未暴露耳蜗的许多区域检测到三种蛋白质（EGRI，TR 77/TR 3和IP 10）。暴露于120 dB噪声后，这些蛋白质以更高的水平存在，或在耳蜗的其他区域显示出扩展的表达。LIF在未暴露大鼠的耳蜗中检测不到，但在噪声后的Corti器和螺旋神经节神经元中可以看到。NUR 77/TR 3在噪音之前是一种核蛋白，但在噪音之后转移到细胞质。这些研究为哺乳动物耳蜗对噪声过度刺激的分子反应提供了新的见解。(C)2004 Elsevier B. V.保留所有权利。
In mammals, exposure to intense noise produces a permanent hearing loss called permanent threshold shift (PTS), whereas a moderate noise produces only a temporary threshold shift (TTS). Little is known about the molecular responses to such high intensity noise exposures. In this study we used gene arrays to examine the early response to acoustic overstimulation in the rat cochlea. We compared cochlear RNA from noise-exposed rats with RNA from unexposed controls. The intense PTS noise induced several immediate early genes encoding both transcription factors (c-FOS, EGRI, NUR77/TR3) and cytokines (PC3/BTG2, LIF and IP10). In contrast, the TTS noise down-regulated the gene for growth hormone. The response of these genes to different noise intensities was examined by quantitative RT-PCR 2.5 h after the 90-min noise exposure. For most genes, the extent of induction correlates with the intensity of the noise exposure. Three proteins (EGRI, NUR77/TR3, and IP10) were detected in many regions of the unexposed cochlea. After exposure to 120 dB noise, these proteins were present at higher levels or showed extended expression in additional regions of the cochlea. LIF was undetectable in the cochlea of unexposed rats, but could be seen in the organ of Corti and spiral ganglion neurons following noise. NUR77/TR3 was a nuclear protein before noise, but following noise translocated to the cytoplasm. These studies provide new insights into the molecular response to noise overstimulation in the mammalian cochlea. (C) 2004 Elsevier B.V. All rights reserved.