Mononuclear phagocyte activi in cochlea acoustic trauma

描述(申请人提供)：拟议研究的长期目标是提高我们目前对炎症在听觉损伤后内耳结构和功能修复和恢复中的作用的了解。其具体目的是1)研究噪声对内耳单核细胞迁移和增殖的影响；2)确定噪声损伤后产生哪些细胞因子以及它们在哪里产生；3)确定如果单核细胞迁移受到抑制，噪声暴露的结果是否会改变。这项拟议的研究不仅涉及听力损失的治疗和预防，而且涉及其他形式的听力损失的治疗和预防，这些形式的听力损失被认为是部分的，由炎症引起，对免疫抑制治疗有反应，如免疫介导性内耳疾病、病毒性迷路炎或突发性听力损失。这项研究设计包括将近亲交配的小鼠暴露在八度频带噪声中，并识别从免疫系统招募的细胞类型，以应对组织损伤。在对这些细胞进行鉴定和量化后，将使用BrdU染色评估听力外周的巨噬细胞和单核细胞的增殖情况。接下来，将使用定量聚合酶链式反应对内耳中的IL-1、IL-6和肿瘤坏死因子进行测量。一旦巨噬细胞的内源性种群得到了很好的描述，缺乏巨噬细胞迁移的基因敲除小鼠将被测试它们对声学损伤的反应。本项目使用的方法包括定量形态计量学、听觉脑干反应测试、免疫细胞化学和定量PCR。

DESCRIPTION (provided by applicant): The long term objectives of the proposed research is to improve our current understanding of the role of inflammation in repair and recovery of inner ear structure and function after acoustic injury. The specific aims are 1) investigate the effect of noise on monocyte migration and proliferation in the inner ear 2) determine which cytokines are produced and where they are produced after noise injury, and 3) determine if the outcome of noise exposure is altered if monocytes migration is inhibited. This proposed research pertains to the treatment and prevention of hearing loss, not only in cases of acoustic trauma, but in other forms of hearing loss that are thought to be part, induced by inflammation and are responsive to immunosuppressive therapies, such as immune-mediated inner ear disease, viral labyrinthitis, or sudden onset hearing loss. The research design involves exposing inbred mice to octave band noise and identifying the cell types that are recruited from the immune system in response to tissue injury. Following identification and quantification of these cells, proliferation of macrophages and monocytes in the auditory periphery will be assessed using BrdU staining. Next, the cytokines that are elaborated by these cells will be measured using quantitative PCR for IL-1, IL-6 and TNF in the inner ear. Once the endogenous population of macrophages has been well described, knock-out mice that are deficient in macrophage migration will be tested for their response to acoustic injury. Methods used for this project include quantitative morphometry, auditory brainstem response testing, immunocytochemistry and quantitative PCR of the mouse cochlea.