Modeling atypical hemolytic uremic syndrome with hydrogel-based microvasculature-on-chip technologies

项目摘要 非典型溶血性尿毒综合征（阿胡斯）是一种危及生命的疾病，可引起微血管血栓形成， 尤其是肾脏，全球死亡率为25%，并且经常进展为终末期肾衰竭。 疾病（ESRD）1，2.虽然已知阿胡斯与旁路途径的不受控制的激活有关， (AP)补体，AP激活如何引起内皮损伤的潜在病理生理学， 血栓形成仍然不清楚，这在很大程度上限制了阿胡斯的其他疗法的发展。即使有 目前最有效的药物依库珠单抗，许多人仍然患有急性发作，进展为ESRD， 肾外表现，被认为与不受调节的内皮活化有关。的 拟议的工作旨在开发第一个阿胡斯体外模型，该模型包含所有主要的 其组分，包括补体和其他血浆蛋白、血小板、红细胞、完整的 内皮细胞、具有生理生物物理特性的细胞外基质和剪切应力，不仅 提高我们对这种可怕疾病的病理生理学的理解，同时探索新的治疗方法 这可能会改善阿胡斯患者的临床结局。在这里，我们假设一种新的水凝胶基 我们最近发明的“内皮化”微血管芯片， 微环境中，并表现出长期（>2个月）的微血管功能。这可以作为一个在 体外模型的阿胡斯，因为我们的微血管芯片系统能够解耦的复杂的细胞 以及参与免疫应答的分子因子（包括补体和补体激活的调节因子）。 阿胡斯的病理生理学以及定量表征这些因素如何相互作用并导致 内皮损伤或活化。这些因子将灌注到工程化微血管系统中， 内皮功能障碍的生物标志物，如内皮渗透性，减少一氧化氮和增加 活性氧将被真实的实时监测。此外，该系统将允许评估如何 这些因子协同导致在阿胡斯的情况下在工程化微脉管系统中血栓形成 通过定量纤维蛋白形成和血小板聚集体/微血栓大小。因为依库珠单抗只阻断 在补体激活的终末途径中形成膜攻击复合物， 微血管芯片模型将使其他新的治疗策略的测试，以促进 内皮修复 这项研究的成功完成将导致一个新的和强大的阿胡斯模型的发展，获得 更好地了解阿胡斯中的内皮损伤以及更广泛地了解补体系统如何相互作用 止血和血栓形成，并为开发合理的药理学方法提供见解， 阿胡斯和其他血栓性微血管病的管理。

PROJECT SUMMARY ABSTRACT Atypical hemolytic uremic syndrome (aHUS) is a life-threatening disease that causes microvascular thrombosis, especially in the kidneys, with a global mortality rate of 25%, and a frequent progression to end-stage renal disease (ESRD)1,2. While aHUS is known to be associated with uncontrolled activation of the alternative pathway (AP) of complement, the underlying pathophysiology of how AP activation causes endothelial injury and thrombosis remains unclear, which largely limits the development of additional therapies for aHUS. Even with the currently most effective drug, eculizumab, many still suffer from acute flare ups, progression to ESRD, and extra-renal manifestations, which are thought to be associated with unregulated endothelial activation. The proposed work aims to develop the first in vitro model of aHUS that incorporates all of the major components thereof, including complement and other plasma proteins, platelets, red blood cells, intact endothelium, extracellular matrix with physiologic biophysical properties, and shear stress, to not only improve our understanding of the pathophysiology of this feared disease but also to explore new therapeutics that may improve better clinical outcomes for aHUS patients. Here we hypothesize that a novel hydrogel-based “endothelialized” microvasculature-on-a-chip that we recently invented recapitulates the in vivo microvascular microenvironment and exhibits long-term (>2 months) microvasculature functionality. This can be used as an in vitro model for aHUS, as our microvasculature-on-a-chip system enables the decoupling of the complex cellular and molecular factors (including complement and regulators of complement activation) involved in the pathophysiology of aHUS as well as quantitatively characterizes how these factors interact and lead to endothelial injury or activation. These factors will be perfused into the engineered microvasculature, and biomarkers of endothelial dysfunction, such as endothelial permeability, reduced nitric oxide and increased reactive oxygen species, will be monitored in real time. In addition, the system will allow assessment of how these factors synergistically lead to thrombi formation in the engineered microvasculature in the context of aHUS through quantifying fibrin formation and platelet aggregate/microthrombi size. As eculizumab only blocks the formation of the membrane attack complex in the terminal pathway of complement activation, this microvasculature-on-a-chip model will enable the testing of other novel treatment strategies to promote endothelial repair. Successful completion of this study will result in the development of a novel and robust model for aHUS, gain a better understanding of endothelial damage in aHUS and more broadly how the complement system interacts with hemostasis and thrombosis, and provide insights into developing rational pharmacological approaches in the management of aHUS and other thrombotic microangiopathies.