Matrix biophysics and pericyte mechanobiology in (patho)physiological angiogenesis

项目摘要 该项目的长期弧预计将工程化组织缺损的血管化， 治疗微血管疾病，包括心肌梗塞、动脉粥样硬化、肺动脉 高血压、动脉瘤、外周动脉疾病、骨修复、肌肉体积损失、糖尿病伤口，以及 癌为了实现这一目标，该项目将推进我们对局部纤维 细胞外基质（ECM）生物物理信号在新血管形成期间动态地影响周细胞。的 内皮细胞在血管发生和血管生成中的作用是公认的，但周细胞的整个范围 尽管已知它在正常的血管发育中起着重要作用，但对它的了解较少。我们做了一个 令人惊讶的观察是，周细胞在自发组装成3D结构时表现出表型可塑性， 当在天然和合成纤维上培养时， 生物材料在体外，但不是在2D基板上。类似于血管生成的血岛，尖端细胞样突起 从这些由周细胞组成的球状体中萌发和缩回，周细胞转分化以表达内皮细胞 标记。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 形态学、细胞迁移的模式和速率、细胞作用力、突起动力学和核形状 与异染色质重排有关。这些已发表的和初步的研究引起了一个 中心假设，各种基质生物物理参数差异指导新血管形成， 调节周细胞迁移、收缩、突出和表型可塑性。为了验证这个假设，我们将 进一步开发一个神经细胞力传感平台，通过精致的 ECM纤维生物物理参数的可调控制（例如，直径、密度、排列）。在考虑 模拟疾病的生物化学环境（例如，氧张力、活性氧和炎症 细胞因子），在目标1下进行的实验将确定基质生物物理线索如何改变周细胞 迁移、收缩性和突出动力学。目的2：研制体外生物可降解支架材料 通过工程控制选择性移植体内图案化球状体以形成新血管的系统 周细胞可塑性和转分化。该项目的翻译影响将是新的方法， 控制患病、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.