Novel Approaches for Prevention and Treatment of Noise Induced Hearing loss

描述（由申请人提供）：噪声性听力损失（NIHL）在美国是一个严重的问题，影响到所有年龄组约15%的人。这些人在工作场所或休闲活动中暴露于巨大的噪音。国家耳聋和沟通障碍研究所最近的一份报告显示，3000万美国人经常暴露在危险的噪音水平下。慢性噪声暴露会导致内耳结构的不可逆损伤和听力损失。目前还没有已知的NIHL治疗方法，这表明开发有效的治疗方案势在必行。我们实验室的最新数据表明，噪声创伤后耳蜗中活性氧（ROS）的产生和炎症介质的增加。因此，我们假设NIHL是由耳蜗中ROS的产生引发的，ROS促进耳蜗炎症，导致内耳细胞的损伤和死亡。这种炎症反应的介质包括耳蜗特异性NADPH氧化酶，NOX 3（ROS产生的主要来源）和瞬时受体电位V1（TRPV 1），一种非特异性阳离子通道，由ROS诱导并参与耳蜗炎症。因此，ROS作为耳蜗炎症反应的常见介质，对噪声创伤。因此，靶向抑制NOX 3和/或TRPV 1将构成NIHL的治疗选择。我们已经确定了一种新的药物，transplatin，通过抑制TRPV 1，NOX 3和炎症介质来改善NIHL。该项目的总体目标是检查ROS介导的炎症在NIHL中的作用，并确定反铂抑制这些促炎介质是否提供耳保护。具体目标1（子目标1A）将确定提供保护的transplatin的有效剂量，并检查该药物在噪音创伤后有效的时间窗。子目标1B将确定噪声暴露后给予transplatin是否会提供耳保护。将通过听觉脑干反应（ABR）和扫描电子显微镜（SEM）评估经鼓室和腹膜内给药途径的疗效。具体目标2将评估transplatin耳保护的分子基础。具体地，子目标2A将使用全转录物微阵列确定噪声和/或transplatin后耳蜗的基因表达谱，与对照相比。将通过定量PCR和Western印迹法进行靶基因/miRNA验证。子目标2B将重点关注噪声创伤后耳蜗微阵列识别的耳蜗促炎基因通路。总体而言，本研究将提供有关NIHL耳蜗基因表达谱的全面数据，并更全面地了解transplatin对NIHL的疗效和作用机制。这些信息可能会突出潜在的新的信号通路介导的NIHL，并提供新的药物治疗靶点。这种方法在动物研究中的成功结果有望直接应用于治疗人类NIHL。

DESCRIPTION (provided by applicant): Noise induced hearing loss (NIHL) is a significant problem in the United States, affecting ~15 percent of individuals from all age groups. These individuals are exposed to loud noise in their workplace or during leisure activities. A recent report by the National Institute of Deafness and Communicative Disorder indicated that 30 million Americans are exposed to hazardous levels of noise regularly. Chronic noise exposure leads to irreversible damage to inner ear structures and hearing loss. There are no known treatments available for NIHL, suggesting that it is imperative to develop effective treatment options. Recent data from our laboratory, indicate increased reactive oxygen species (ROS) generation and increased inflammatory mediators in the cochlea after noise trauma. Thus we hypothesize that NIHL is initiated by the generation of ROS in the cochlea which promote coclear inflammation, leading to damage and death of cells in the inner ear. Mediators of this inflammatory response include the cochlear specific NADPH oxidase, NOX3 (a primary source of ROS generation) and transient receptor potential V1 (TRPV1), a nonspecific cation channel, which is induced by ROS and participates in the cochlear inflammation. Thus, ROS serve as common mediator of cochlear inflammation in response to noise trauma. As such, targeting NOX3 and/or TRPV1 for inhibition would constitute treatment options for NIHL. We have identified a novel agent, transplatin, which ameliorates NIHL by inhibiting TRPV1, NOX3 and inflammatory mediators. The overall goal of this project is to examine the role of ROS mediated inflammation in NIHL and to determine if inhibition of these pro- inflammatory mediators by transplatin provides otoprotection. Specific aim 1 (sub-aim 1A) will determine the effective doses of transplatin providing protection and examine the time-window for this drug to be effective prophylactically and as a rescue agent after noise trauma. Sub-aim 1B will determine whether administration of transplatin following noise exposure would provide otoprotection. The efficacy of both trans-tympanic and intraperitoneal routes of administration will be assessed by auditory brainstem responses (ABRs) and scanning electron microscopy (SEM). Specific aim 2 will assess the molecular basis of transplatin otoprotection. Specifically, sub-aim 2A will determine the gene expression profile of the cochlea after noise and/or transplatin, compared to control, using whole transcript microarrays. Target gene/miRNA validation will be performed by quantitative PCR and Western blotting. Sub-aim 2B will focus on cochlear pro-inflammatory gene pathways identified by microarray of the cochlea after noise trauma. Overall, this study will provide comprehensive data regarding gene expression profile of the cochlea in NIHL and provide a more complete picture of the efficacy and mechanism of action of transplatin against NIHL. This information could highlight potentially new signaling pathways mediating NIHL and provide novel drug treatment targets. A successful outcome of this approach in the animal studies is expected to have direct translational application for the treatment of NIHL in human.