Senescence-Chips for Radiation Biodosimetry

描述（由申请方提供）：放射性/核恐怖事件后急性和迟发性辐射损伤的理想生物标志物是在组织损伤表现之前出现并可测量的生物标志物，通常是在电离辐射（IR）暴露后1至几天。它们还应该以非侵入性或微创方式进行测量-例如，使用外周血样本。大剂量IR可引起造血和实体组织的急性和迟发性损伤。造血干细胞（HSC）和间充质干细胞（MSC）对于再生和修复这些组织至关重要。MSC分化成骨细胞、软骨细胞和脂肪细胞，而HSC是各种类型血细胞的前体。我们发现，造血干细胞和骨髓间充质干细胞经历IR诱导的衰老，一个稳定的有丝分裂后的状态，IR后。相反，大多数分化的血细胞经历IR后凋亡，并迅速清除。HSC和MSC通常存在于骨髓中，但总是可以从外周血中检测和分离出少量。在这个SBIR项目中，我们建议使用细胞衰老作为辐射生物剂量学的生物终点。我们将开发集成的微流控芯片，称为“衰老芯片”，用于快速准确地检测衰老细胞，特别是IR诱导的衰老HSC和MSC，以及由于衰老相关分泌表型（SASP）而引起的循环细胞因子/趋化因子，从少量人外周血中。该项目建立在我们最近发表的表征HSC和MSC的IR诱导衰老的进展，SASP作为衰老细胞的稳定（慢性）表型，以及一种新的小鼠模型（p16- 3 MR C57 BL/6小鼠）的开发上，该模型使我们能够识别，跟踪-重要的是，诱导性地杀死-体内和随意的衰老细胞。我们的新型微流控芯片包含多个功能模块，这些模块将捕获和计数HSC和MSC的总群体和衰老群体，直至单个细胞，并同时检测外周血中的SASP。这些芯片将使用细胞系、小鼠模型和人类临床样本进行验证。衰老芯片将使低成本，可重复的，高特异性和灵敏度的多路测量人类外周血的辐射生物剂量测定，从而作为一个现场部署的平台，放射/核医学对策，包括紧急分流和医疗反应。

DESCRIPTION (provided by applicant): Ideal biomarkers of acute and delayed radiation injury after a radiological/nuclear terrorist incident are those that arise and are measurable prio to manifestation of tissue injuries, typically one to a few days after ionizing radiation (IR) exposure. They should also be measurable in a non-invasive or minimally invasive way - for example, using peripheral blood samples. High-dose IR induces acute and delayed injuries to both hematopoietic and solid tissues. Hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) are critical for regenerating and repairing these tissues. MSCs differentiate into osteoblasts, chondrocytes, and adipocytes while HSCs are precursors of various types of blood cells. We showed that HSCs and MSCs undergo IR-induced senescence, a stable post-mitotic state, after IR. In contrast, most differentiated blood cells undergo apoptosis after IR and are quickly cleared. HSCs and MSCs generally reside in the bone marrow, but small numbers can always be detected and isolated from peripheral blood. In this SBIR project, we propose to use cellular senescence as the biological end-point for radiation biodosimetry. We will develop integrated microfluidic chips, termed "Senescence-Chips", for rapid and accurate detection of senescent cells, particularly, IR-induced senescent HSCs and MSCs, as well as circulating cytokines/chemokines due to the senescence-associated secretory phenotype (SASP), from small volumes of human peripheral blood. The project builds on our recently published progress in characterizing the IR-induced senescence of HSCs and MSCs, the SASP as a stable (chronic) phenotype of senescent cells, and the development of a new mouse model (p16-3MR C57BL/6 mice) that allows us to identify, track - and, importantly, inducibly kill - senescent cell in vivo and at will. Our novel microfluidic chips contain multiple functional modules that will capture and enumerate the total and senescent populations of HSCs and MSCs, down to single cells, and simultaneously detect SASP, in peripheral blood. The chips will be validated using cell lines, mouse models, and human clinical samples. Senescence-chips will enable low-cost, reproducible, highly specific and sensitive multiplex measurements of human peripheral blood for radiation biodosimetry, thus serving as a field-deployable platform for radiological/nuclear medical countermeasures including emergency triage and medical responses.