Matrix biophysics and pericyte mechanobiology in (patho)physiological angiogenesis

项目总结 这个项目的长期弧形有望促进组织缺损区的血管形成并取得进展 微血管疾病的治疗，包括心肌梗死、动脉粥样硬化、肺动脉 高血压，动脉瘤，外周动脉疾病，骨修复，体积肌肉丧失，糖尿病伤口，以及 癌症。为了实现这一目标，该项目将促进我们对当地纤维如何形成的基本理解 细胞外基质(ECM)生物物理信号在新生血管形成过程中动态影响周细胞。这个 内皮细胞在血管生成和血管生成中的作用是公认的，但周细胞的全部范围 尽管已知其在正常血管发育中的重要作用，但人们对其了解较少。我们做了一个 令人惊讶的观察到，当周细胞自发组装成3D时，它们表现出表型可塑性 当在天然和合成纤维上培养时，球体和可逆地形成和采用内皮标记 生物材料在体外，但不是在2D基质上。类似于血管生成的血岛，尖端细胞样突起 由转分化的周细胞组成的球体萌发和收缩，表达内皮细胞 记号笔。我们团队的其他研究表明，基质纤维直径和结构决定了细胞 形态、细胞迁移的方式和速率、细胞作用力、突起动力学和核形状 与异色重排有关。这些已发表的和初步的研究产生了一个 中心假设不同的基质生物物理参数通过以下方式不同地指导新星的形成 调节周细胞迁移、收缩、突起和表型可塑性。为了检验这一假设，我们将 进一步开发一种纳米纤维细胞力传感平台，通过精致的 ECM纤维生物物理参数(例如，直径、密度、排列)的可调控制。考虑到 模拟疾病的生化环境(例如，氧分压、活性氧物种和炎症 细胞因子)，在目标1下进行的实验将确定基质生物物理信号如何改变周细胞 迁移、收缩和突起动力学。目的2实验将开发体外纳米纤维支架 通过工程控制在体内选择性移植有图案的球体以形成新生血管的系统 周细胞的可塑性和转分化。该项目的翻译影响将是新的方法 控制病变、受损和工程化组织中的微血管扩张和消退。

PROJECT SUMMARY The long-term arc of this project is expected to engineer vascularization of tissue deficits and advance treatment of microvascular diseases including myocardial infarction, atherosclerosis, pulmonary arterial hypertension, aneurysm, peripheral artery disease, bone repair, volumetric muscle loss, diabetic wounds, and cancer. To achieve this goal, the project will advance our fundamental understanding of how local fibrous extracellular matrix (ECM) biophysical cues dynamically influence pericytes during neovessel formation. The role of the endothelial cell in vasculogenesis and angiogenesis is well recognized, yet the pericyte’s full scope of work is less understood, despite its known essential role in proper vascular development. We made a surprising observation that pericytes exhibit phenotypic plasticity when they spontaneously assemble into 3D spheroids and reversibly form and adopt endothelial markers when cultured on native and synthetic fibrous biomaterials in vitro, but not on 2D substrates. Akin to vasculogenic blood islands, tip cell-like protrusions sprout and retract from these spheroids comprised of pericytes that transdifferentiate to express endothelial markers. Other studies by our team revealed that matrix fiber diameter and architecture dictate cell morphology, the mode and rate of cell migration, cell force exertion, protrusion dynamics, and nuclear shape associated with heterochromatic rearrangements. These published and preliminary studies gave rise to a central hypothesis that various matrix biophysical parameters differentially direct neovessel formation by modulating pericyte migration, contraction, protrusion, and phenotypic plasticity. To test this hypothesis, we will further develop a nanofiber cell force sensing platform to mimic (patho)physiological ECMs through exquisite tunable control of ECM fiber biophysical parameters (e.g., diameter, density, alignment). With consideration of disease-simulating biochemical milieu (e.g., oxygen tension, reactive oxygen species, and inflammatory cytokines), experiments performed under Aim 1 will identify how matrix biophysical cues alter pericyte migration, contractility, and protrusion dynamics. Aim 2 experiments will develop the in vitro nanofiber scaffold system to selectively transplant patterned spheroids in vivo for neovessel formation through engineered control of pericyte plasticity and transdifferentiation. The project’s translational impact will be novel methods of controlling microvascular expansion and regression in diseased, damaged, and engineered tissues.