Discovering tissue-specific biomarkers of radiation injury in SILAC-labeled mice

描述（由申请方提供）：在全身辐射暴露为3-8戈伊时，主要死亡原因是造血综合征。这些死亡中有许多是可以通过对受害者进行细胞因子治疗和积极的支持性护理来预防的。不幸的是，目前用于识别处于造血综合征风险中的患者的模式遭受不准确、高费用、长分析时间和延迟诊断。此外，这些方法中没有一种直接测量骨髓的辐射损伤，也没有表明残留造血的存在，并且大多数方法在紧急情况下不适合即时护理。因此，对于在放射性事件之后使用的可现场部署的诊断，存在关键的未满足的需求，以识别将发展潜在致命但通常可治疗的造血综合征的受害者。 我们建议在临床诊断中建立一个非常成功的范例，即受损组织泄漏，脱落和/或分泌蛋白质 进入血浆，在那里它们是指示组织损伤程度的有用生物标志物。包括心肌梗死中的肌钙蛋白、肝损伤中的转氨酶、肌肉损伤中的肌酸激酶和胰腺过程中的脂肪酶。因此，我们假设在辐射诱导的骨髓损伤后，蛋白质从骨髓释放到血流中，在那里它们提供预测造血综合征的发作和严重程度的有用的生物标志物信号。我们建议使用一种创新的方法来识别辐射诱导的骨髓损伤的这些血浆生物标志物，该方法结合了我们在生物标志物发现管道中开发和验证的靶向蛋白质组学技术，与传统方法相比，通过测试大量（前所未有的）血浆生物标志物候选物，将大大增加我们成功的机会。 目标1。使用SILAC标记的小鼠，鉴定骨髓中对辐射反应诱导的蛋白质，随后测试数百种这些推定的组织损伤标志物，以鉴定暴露后血浆中稳定升高的亚组。目的2：表征目的1中鉴定的候选骨髓损伤生物标志物，关于它们：血浆中随时间、剂量范围和剂量率的稳定性B.与临床终点（造血综合征的指标）的相关性c.对造血系统损伤和辐射引起的损伤的特异性d.在异质人群（儿科、老年、性别、遗传易感）中使用目的3。确定在小鼠中识别的骨髓损伤的辐射生物标志物中哪些在辐射暴露后在人血液中升高，并开发一种即时检测装置，该装置将成为后续人体临床验证试验的基础（超出本提案）。

DESCRIPTION (provided by applicant): At total body radiation exposures of 3-8 Gy, the predominant cause of death is the hematopoietic syndrome. Many of these deaths are preventable with rapid triage of victims for cytokine therapies and aggressive supportive care. Unfortunately current modalities for identifying patients at risk for the hematopoietic syndrome suffer from inaccuracy, high expense, long analysis times, and delayed diagnosis. Furthermore, none of these methods directly measures radiation damage to the bone marrow, nor do they indicate the existence of residual hematopoiesis, and most are not amenable to point-of-care in emergency conditions. Thus, there is a critical unmet need for a field-deployable diagnostic for use following a radiological incident to identify victims who will develop the potentially fatal ye often treatable hematopoietic syndrome. We propose to build upon a highly successful paradigm in clinical diagnostics, which is that injured tissues leak, shed, and/or secrete proteins into the plasma, where they are useful biomarkers indicating the extent of tissue injury. Precedents include the troponins in myocardial infarction, transaminases in liver injury, creatine kinase in muscle injury, and lipase in pancreatic processes. Accordingly, we hypothesize that following radiation-induced injury to the bone marrow, proteins are released from the marrow into the bloodstream, where they provide useful biomarker signals predictive of the onset and severity of the hematopoietic syndrome. We propose to identify these plasma biomarkers of radiation-induced marrow injury using an innovative approach incorporating targeted proteomic technologies that we have developed and validated in a biomarker discovery pipeline that will substantially increase our chances of success compared with traditional approaches by enabling the testing of a very large (unprecedented) number of plasma biomarker candidates. Aim 1. Using SILAC-labeled mice, identify proteins induced in the bone marrow in response to radiation, and subsequently test hundreds of these putative tissue injury markers to identify the subset that are stably elevated in the plasma post-exposure. Aim 2: Characterize candidate marrow injury biomarkers identified in Aim 1 with respect to their: a. stability in plasma over time, dose range, and dose rates b. correlation with clinical endpoints (indicators of hematopoietic syndrome) c. specificity for damage to the hematopoietic system and damage caused by radiation d. use across a heterogeneous population (pediatric, geriatric, gender, genetically susceptible) Aim 3. Determine which of the radiation biomarkers of marrow damage identified in the mouse are elevated in human blood following radiation exposure, and develop a point-of-care assay device that will form the basis of subsequent human clinical validation trials (beyond this proposal).