Organ-specific NRF2-mediated protein signatures of radiation exposure & tissue da

描述（由申请人提供）：本提案的总体理由是为暴露于电离辐射（IR）的个体开发一种血液测试，以提供暴露和暴露相关器官损伤的个人分子特征，指导治疗方案，并可能反馈治疗效果。我们将进行假设驱动的靶向蛋白质组学实验，重点研究nrf2介导的小鼠对IR的反应。这些实验将涉及一系列不同年龄和性别的小鼠品系，并将研究目标器官的红外暴露。之所以选择NRF2介导的应答蛋白，是因为我们之前的研究表明，2至8 Gy的单剂量电离辐射（通过NRF2）以剂量依赖的方式激活乳腺癌细胞中抗氧化应答元件（ARE）依赖的转录，但仅在延迟一天或更长时间后。迟发性和长期的反应对于预期的生物标志物理性是特别有用的。我们最初的实验将集中在暴露于ir的小鼠的器官和富集的血液亚组分上，以提供一组潜在的组织特异性生物标志物，用于后续研究它们在血浆中的特异性存在。因此，我们的实验将解决三个一般假设；有许多nrf2调节的蛋白会以剂量依赖的方式在组织中发生变化，以响应IR；损伤模式将提供分子特征，报告整体辐射暴露的严重程度，以及特定的个体器官应激/损伤；其中一些潜在的生物标记物会泄漏到血液中并持续存在，这样它们就可以在血浆中测量，用于人体血液测试。虽然我们的实验侧重于IR剂量依赖性反应，但我们注意到，通过靶向个体器官特异性的应激蛋白，我们可能会发现报告个体健康/痛苦的生物标志物，无论剂量如何，从而适应具有异常敏感性的个体。

DESCRIPTION (provided by applicant): The overall rational of this proposal is to develop a blood test for individuals exposed to ionizing radiation (IR) to provide a personal molecular signature of exposure and exposure-related organ damage, for guidance of treatment options, and potentially for feedback of efficacy of treatment. We will perform hypothesis-driven targeted proteomics experiments that focus upon NRF2-mediated responses to IR in mice. The experiments will address a range of mouse strains, of varying age and sex, and will investigate targeted organ IR exposure. NRF2-mediated response proteins were chosen because we previously showed that single doses of ionizing radiation from 2 to 8 Gy activated antioxidant response element (ARE)-dependent transcription (via NRF2) in breast cancer cells in a dose-dependent manner, but only after delays of a day or more. Late onset and long- lived responses are especially useful for the intended biomarker rational. Our initial experiments will focus on organs and enriched sub-fractions of blood from IR-exposed mice, to provide a panel of potential tissue- specific biomarkers, for subsequent investigation of their specific presence in blood plasma. Thus our experiments will address three general hypotheses; that there are a number of NRF2-modulated proteins that will change in tissues in a dose-dependent manner in response to IR; that the patterns of damage will provide molecular signatures that report severity of overall radiation exposure, and specific individual organ stress/damage; and that some of these potential biomarkers will leak into the blood stream and persist so that they can be measured in plasma, toward human blood tests. While our experiments focus upon IR dose- dependent responses, we note that by targeting stress proteins specific to individual organs we may find biomarkers that report individual health/distress, regardless of dose, thereby accommodating individuals with unusual sensitivity. PUBLIC HEALTH RELEVANCE: The overall rational of this proposal is the development of a blood test for individuals exposed to ionizing radiation (IR) to provide a personal molecular signature of exposure and exposure-related organ damage, for guidance of treatment options, and potentially for feedback of efficacy of treatment. The proposed work focuses upon proteins involved in delayed anti-oxidant responses to IR in different organs from IR-exposed mice, and will test for the presence of these proteins in blood. The experiments will address a range of mouse strains, of varying age and sex, and will investigate targeted organ IR exposure.