Determination of Metabolic State of Hair Cell Mitochondria by FLIM

描述（由申请人提供）：感音神经性听力损失的近因是不可替代的耳蜗毛细胞的死亡，但毛细胞对各种创伤和疾病的选择性脆弱性的潜在基础尚不清楚。一个突出的理论是毛细胞无法科普代谢需求，这将由此引发线粒体胱天蛋白酶介导的凋亡，但该理论的证据是间接的。正如我们在这里显示，现在可以评估状态的氧化代谢毛细胞线粒体的排放减少尼古丁腺嘌呤二核苷酸，氧化磷酸化的中间体。该提案寻求支持，以开发这种成像技术的应用，在毛细胞的代谢成像的问题。我们进一步要求支持测试的假设，即耳蜗外毛细胞的脆弱性相比，内毛细胞，和基底转毛细胞相比，顶转毛细胞的已知差异，与各自的毛细胞群体的代谢反应的差异。我们认为，拟议的开发和实验代表了活毛细胞氧化代谢定量新时代的第一步，这将大大增加我们对规范和病理耳蜗生理学许多方面的理解。叙述性耳聋是人口残疾的主要原因，随着人口老龄化，其重要性可能会增加。耳聋的主要形式，称为感觉神经性耳聋，涉及不可替代的毛细胞的损失，这可能是由于无法科普代谢挑战。我们的项目是评估一种新的方法来量化活毛细胞的代谢状态。

DESCRIPTION (provided by applicant): The proximate cause of sensorineural hearing loss is the death of irreplaceable cochlear hair cells, but the underlying basis of the selective vulnerability of hair cells to a variety of traumas and diseases is unknown. A prominent theory is the inability of hair cells to cope with metabolic demands, which would thereby trigger mitochondrial caspase- mediated apoptosis, but evidence for this theory is indirect. As we here show, it is now possible to assess the state of oxidative metabolism in hair cell mitochondria from the emissions of reduced nicotine adenine dinucleotide, an intermediate in oxidative phosphorylation. This proposal seeks support to develop application of this imaging technique to the problem of metabolic imaging in hair cells. We further request support to test the hypothesis that known differences in the vulnerability of cochlear outer hair cells compared to inner hair cells, and of basal turn hair cells compared to apical turn hair cells, correlate with differences in metabolic responses in the respective hair cell populations. The proposed development and experiments, we believe, represent the first steps in a new era of quantitation of oxidative metabolism in living hair cells that will greatly add to our understanding of many aspects of normative and pathological cochlear physiology. PUBLIC HEALTH RELEVANCE Narrative Deafness is a major cause of disability in the population and is likely to increase in significance as the population ages. The major form of deafness, called sensorineural, involves the loss of irreplaceable hair cells, which may be due to an inability to cope with metabolic challenges. Our project is to evaluate a new method of quantifying the metabolic state of living hair cells.