Mechanisms of Cochlear Oxidative Stress Injury and Strategies to Protect Hearing

描述（由申请人提供）：这个职业发展奖的目标是建立一个富有成效的研究计划，在听觉研究，这将促进我过渡到一个独立的临床医生，科学家在耳鼻喉科。该培训计划包括由外部咨询委员会指导的指导研究计划和结构化的职业发展活动。综合指导团队包括医学博士伦纳德·里巴克，博士作为导师和维克拉姆·拉姆库马尔博士，和凯瑟琳坎贝尔博士作为共同导师该奖项将为患者导向的科学研究的可持续职业生涯奠定基础。实验工作重点是庆大霉素（一种原型氨基糖苷类药物）治疗后导致内耳氧化应激损伤的分子机制。 氨基糖苷类抗生素在治疗危及生命的感染方面继续发挥重要作用，但它们也与永久性双侧听力损失以及平衡障碍、耳鸣和肾毒性的风险相关。作为一名耳鼻喉科医生，我照顾患有各种疾病的儿童和成人，这些疾病影响他们有效表达自己或在社会中发挥最佳作用的能力。对于听力损失患者，我 可以看到沟通障碍对他们生活的深远影响。我长期致力于在实验室中取得发现并将其带到床边，这为这项转化研究计划提供了动力。研究策略强调氧化应激的作用，基于先前的研究表明，活性氧有助于药物诱导和噪音诱导的听力损失，抑制这些活性氧可能会提供耳保护。不同类型的耳部损伤可能会汇聚在共同的分子途径上，导致耳蜗炎症并最终导致毛细胞死亡。这项研究计划的中心假设是，有针对性地干预氧化应激可以减轻耳蜗炎症，从而降低庆大霉素诱导的内耳损伤的风险。使用有针对性的方法也可以降低严重副作用的风险。这项为期五年的研究计划包括一系列相关的实验，研究庆大霉素耳毒性的机制和transplatin作为一种潜在的耳保护剂的作用。Transplatin是顺铂的一种无活性的反式异构体，可减少与药物诱导的听力损失有关的几种关键分子的表达。通过经鼓膜或全身途径递送transplatin，在动物模型中确定transplatin保护的剂量-反应效应。将通过扫描电子显微镜、听性脑干反应测试和免疫组织化学测定进行评估。耳蜗衍生细胞系的实验将研究transplatin如何调节耳蜗中的氧化应激、基因表达和炎症。这项工作将更好地确定细胞膜通道，转录因子和其他分子靶点在庆大霉素诱导的听力损失中的作用。本研究的长期目标是开发安全有效的策略来预防氨基糖苷类抗生素治疗相关的听力损失。

DESCRIPTION (provided by applicant): The goal of this career development award is to establish a productive research program in auditory research that will foster my transition to an independent clinician-scientist in otolaryngology. This training program comprises a mentored research plan with guidance by an external advisory committee and structured career-enhancing activities. The integrated mentoring team includes Leonard Rybak, M.D.,Ph.D. as mentor and Vickram Ramkumar, Ph.D., and Kathleen Campbell, Ph.D. as co-mentors. This award will lay the groundwork for a sustainable career in patient-directed scientific investigation The experimental work focuses on the molecular mechanisms responsible for oxidative stress injury to the inner ear after treatment with gentamicin, a prototype aminoglycoside. Aminoglycoside antibiotics continue to have an essential role in the treatment of life-threatening infections, but they are also associated with a risk of permanent, bilateral hearing loss, as well as balance disturbance, tinnitus, and nephrotoxicity. As an otolaryngologist, I care for children and adults suffering from a broad range of disorders that affect their ability to express themselves effectively or to function optimally in society. For those patients with hearing loss, I can see the far-reaching effects of impaired communication on their lives. My longstanding commitment to taking findings in the laboratory and bringing them to the bedside provides the impetus for this translational research program. The research strategy emphasizes the role of oxidative stress based on prior studies showing that reactive oxygen species contribute to drug-induced and noise-induced hearing loss and that dampening these reactive oxygen species may confer otoprotection. Different types of insults to the ear may converge on common molecular pathways to cause cochlear inflammation and ultimately hair cell death. The central hypothesis of this research plan is that targeted interference with oxidative stress can attenuate cochlear inflammation and in doing so decrease the risk of gentamicin-induced injury to the inner ear. Use of a targeted approach may also decrease the risk of serious side effects. The five-year research plan involves a series of related experiments that investigate the mechanisms of gentamicin ototoxicity and the role of transplatin as a potential otoprotectant. Transplatin is an inactive trans-isomer of cisplatin that reduces expression of several key molecules involved in drug-induced hearing loss. A dose-response effect for transplatin protection will be determined in an animal model by delivering transplatin via transtympanic or systemic routes. Assessments will be made by scanning electron microscopy, auditory brainstem response testing, and immunohistochemical assays. Experiments in cochlea-derived cell lines will investigate how transplatin modulates oxidative stress, gene expression, and inflammation in the cochlea. This work will better define the role of cell membrane channels, transcription factors, and other molecular targets in gentamicin-induced hearing loss. The long-term goal of this research is to develop safe and effective strategies to prevent hearing loss related to aminoglycoside antibiotic therapy.