Mononuclear phagocyte activi in cochlea acoustic trauma

描述（由申请人提供）：拟议研究的长期目标是提高我们目前对内耳损伤后炎症在内耳结构和功能修复和恢复中的作用的理解。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何处产生；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。这项拟议的研究涉及听力损失的治疗和预防，不仅涉及声创伤，还涉及其他形式的听力损失，这些听力损失被认为是部分由炎症引起的，对免疫抑制疗法有反应，如免疫介导的内耳疾病、病毒性迷路炎或突发性听力损失。研究设计包括将近亲繁殖的小鼠暴露在倍频带噪声中，并识别组织损伤时从免疫系统中招募的细胞类型。在对这些细胞进行鉴定和定量后，将使用BrdU染色评估听觉周围巨噬细胞和单核细胞的增殖情况。接下来，将使用内耳中IL-1、IL-6和TNF的定量PCR来测量这些细胞产生的细胞因子。一旦内源性巨噬细胞群体被很好地描述，巨噬细胞迁移缺陷的敲除小鼠将被测试其对声损伤的反应。本项目使用的方法包括小鼠耳蜗的定量形态学、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.