Novel Approaches for Prevention and Treatment of Noise Induced Hearing loss

描述（由申请人提供）：噪音引起的听力损失（NIHL）在美国是一个严重的问题，影响着所有年龄组中约15%的人。这些人在工作场所或休闲活动时暴露在巨大的噪音中。国家耳聋和交流障碍研究所最近的一份报告表明，3000万美国人经常暴露在危险水平的噪音中。长期接触噪音会对内耳结构造成不可逆转的损害和听力丧失。目前还没有已知的NIHL治疗方法，这表明必须开发有效的治疗方案。我们实验室最近的数据表明，噪音创伤后耳蜗中活性氧（ROS）的产生增加，炎症介质增加。因此，我们假设NIHL是由耳蜗中ROS的产生引发的，ROS促进了核性炎症，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、NOX3 （ROS生成的主要来源）和瞬时受体电位V1 (TRPV1)，这是一种由ROS诱导并参与耳蜗炎症的非特异性阳离子通道。因此，活性氧是耳蜗对噪音创伤反应的常见介质。因此，靶向NOX3和/或TRPV1进行抑制将成为NIHL的治疗选择。我们已经确定了一种新的药物——移植素，它通过抑制TRPV1、NOX3和炎症介质来改善NIHL。该项目的总体目标是研究ROS介导的炎症在NIHL中的作用，并确定通过移植抑制这些促炎介质是否提供耳保护。具体目标1（子目标1A）将确定提供保护的移植药物的有效剂量，并检查该药物在噪声创伤后有效预防和作为救援剂的时间窗口。子目标1B将确定噪音暴露后进行移植治疗是否会提供耳部保护。通过听觉脑干反应（ABRs）和扫描电子显微镜（SEM）来评估跨鼓室和腹腔给药途径的疗效。特异性目标2将评估移植耳保护的分子基础。具体而言，子目标2A将使用全转录物微阵列，与对照组相比，确定噪声和/或移植后耳蜗的基因表达谱。目的基因/miRNA验证将通过定量PCR和Western blotting进行。亚目标2B将重点研究噪声损伤后耳蜗微阵列识别的耳蜗促炎基因通路。总的来说，本研究将提供NIHL耳蜗基因表达谱的全面数据，并提供更完整的移植治疗NIHL的疗效和作用机制。这一信息可能会突出介导NIHL的潜在新信号通路，并提供新的药物治疗靶点。该方法在动物研究中的成功结果有望直接转化应用于人类NIHL的治疗。

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.