Multiscale, Transport-Dependent NO Signaling: Cells to Vascular Networks

描述（由申请人提供）：拟议研究的目标是开发一个独特的多尺度数学模型，该模型将提供有关微循环中一氧化氮（NO）活性控制机制的定量信息，并利用创新的实时实验来验证该模型。该模型将整合细胞内NO生产过程与细胞外、血管和组织运输，包括正常条件下和高胆固醇血症下NO与O2传递和代谢的耦合。该模型将有助于阐明一氧化氮产生和运输的机制，并为其血管舒张作用提供更深入的了解。虽然一氧化氮（NO）在调节血液流动和代谢中的重要性已得到充分证实，但一氧化氮产生和运输的许多机制尚未完全阐明。重要的是，可能影响一氧化氮生物利用度和血管动力学的各种现象在一定的时间和长度尺度上相互作用。需要一个超越不同空间和时间尺度的数学模型，再加上体外和体内实验，以理解系统的行为。数学建模：开发理念是将低尺度与高尺度模拟依次耦合：细胞尺度到血管尺度，再到血管网络。模拟的预测将通过我们的实验和文献中报道的结果进行验证。In vitr：一个平行板层流室，先前设计和建造，这是我们小组第一次，也是唯一的一次，可以在广泛的条件下直接，实时测量NO释放动力学，将用于细胞培养研究。我们将研究剪切应力和信号分子的质量传递改变对流动诱导NO产生的耦合效应，以分离它们如何影响NO的产生和运输。将结果与仿真结果进行比较。体内实验：将使用大鼠肠系膜和载脂蛋白e缺乏小鼠进行实验。局部血流量、PO2和NO，结合血管直径测量，将在正常和异常生理条件下从单个小动脉、小动脉、小静脉和小静脉中获得，以表征血管直径、NO、血流量和O2输送之间的关系。在缺氧条件下，亚硝酸盐作为一氧化氮来源的影响也将通过血液和组织中o2依赖性亚硝酸盐还原酶的活性进行评估。所提出的模型将导致对完整系统的更好理解，并为未来的研究奠定基础，可以阐明no相关的病理。

DESCRIPTION (provided by applicant): The goal of the proposed research is to develop a unique multi-scale mathematical model that will provide quantitative information regarding mechanisms governing nitric oxide (NO) activity in the microcirculation and to utilize innovative, real-time experiments to validate the model. The model will integrate intracellular NO production processes with extracellular, vascular and tissue transport, including the coupling of NO to O2 delivery and metabolism under normal conditions and in hypercholesterolemia. The model will help to elucidate mechanisms by which NO is produced and transported and provide greater insight into its vasodilatory role. While the importance of nitric oxide (NO) in regulating blood flow and metabolism is well established, many of the mechanisms by which NO is produced and transported have not been fully elucidated. Importantly, the various phenomena that can potentially affect the bioavailability of NO and vascular dynamics interact over a range of time and length scales. A mathematical model that transcends different spatial and time scales, coupled with in vitro and in vivo experiments, is required for understanding of system behavior. Mathematical Modeling: The development philosophy is to sequentially couple lower scale with higher scale simulation: cell-scale to vessel-scale, to vascular networks. Predictions of the simulation will be validated using our experiments and results reported in the literature. In vitr: A parallel plate laminar flow chamber, designed and constructed previously, which -- for the first time and only by our group -- enables direct, real time measurements of the kinetics of NO release under a wide range of conditions will be used for cell culture studies. The coupled effects of shear stress and altered mass transport of signaling molecules on flow- induced NO production will be investigated to isolate how they influence NO production and transport. Results will be compared with the simulations. In vivo: Experiments will be performed using the rat mesentery and apolipoprotein-E deficient mice. Local blood flow, PO2 and NO, combined with vessel diameter measurements, will be obtained from individual small arteries, arterioles, venules, and small veins under normal and abnormal physiological conditions to characterize relationships among vascular diameter, NO, blood flow, and O2 delivery. The effect of nitrite as an NO source from O2-dependent nitrite reductase activity in blood and tissue under hypoxic conditions will also be evaluated. The proposed model will lead to an improved understanding of the complete system, and set the groundwork for future research that can shed light on NO-related pathologies.