Understanding and Controlling Macrophage Behavior in Angiogenesis

项目摘要 血管生成和生物材料血管化的核心是炎症反应， 主要是巨噬细胞，其响应于微环境线索而随着时间的推移显著改变表型。 在对损伤的正常反应中，巨噬细胞最初是促炎性的（又名M1），在后期阶段， 被统称为M2的混合群体所取代，其上调与以下相关的因子： 解决伤口愈合过程。特别是M2种群的多样性程度， 知道的在血管生成和生物材料血管化的后期阶段，M2巨噬细胞1）通过以下途径产生： 从M1巨噬细胞过渡，或2）从新到达的单核细胞的直接分化。的差异 尚未研究来自每个群体的M2巨噬细胞之间的差异。初步数据 表明M1衍生的M2巨噬细胞具有增强的血管生成功能， 瞬时刺激初始M1期可能会增强随后对M2促进的反应。 生物材料，以实现增强的血管化和愈合。这个项目的首要假设是， 促进相同巨噬细胞群体的顺序M1和M2活化的生物材料将增强 血管化为了检验这一假设，这项工作有以下目标：1）确定M1预处理的影响 极化的功能表型的M2巨噬细胞在串扰与血管在体外，使用 原代人巨噬细胞、基因和蛋白质表达谱分析以及 血管生成2)确定促炎性预处理对IL 4 - 1的再生作用的影响。 在体内释放生物材料，使用暂时控制宿主巨噬细胞表型的生物材料， 小鼠后肢缺血模型。3)确定生物材料介导的血管生成的体内效应 巨噬细胞治疗策略，其在细胞内将单个巨噬细胞群体从M1引导至M2。 后一种策略可能会为患有受损的患者提供特别有益的生物材料。 白细胞运输，包括糖尿病患者、自身免疫性疾病患者或 癌症的化学治疗。这项工作将推进我们对生物材料如何被 旨在利用巨噬细胞的炎症和再生功能， 血管生成，这将使我们能够开发新的策略来治疗许多疾病， 病理性血管生成，包括心脏和脑缺血、动脉粥样硬化和糖尿病， 他人此外，该项目还提出了一种新的方法，通过控制组织的血管再生， 使用生物材料的募集和外源性施用巨噬细胞的作用。

Project Summary At the heart of angiogenesis and biomaterial vascularization lies the inflammatory response, orchestrated primarily by macrophages, which dramatically shift phenotype over time in response to microenvironmental cues. In the normal response to injury, macrophages are initially pro-inflammatory (aka M1), and at later stages they are replaced by a mixed population referred to collectively as M2 that upregulate factors associated with resolution of the wound healing process. The extent of the diversity of this M2 population in particular is not known. At later stages of angiogenesis and biomaterial vascularization, M2 macrophages are generated 1) via transition from M1 macrophages, or 2) from direct differentiation of newly arriving monocytes. The differences between the M2 macrophages arising from each population have not been investigated. Preliminary data suggest that M1-derived M2 macrophages possess enhanced angiogenic functionality, and that biomaterials that transiently stimulate the initial M1 phase may enhance the subsequent response to M2-promoting biomaterials to achieve enhanced vascularization and healing. The overarching hypothesis of this project is that biomaterials that promote sequential M1 and M2 activation of the same population of macrophages will enhance vascularization. To test this hypothesis, this work has the following goals: 1) Determine the effects of M1 pre- polarization on the functional phenotype of M2 macrophages in crosstalk with blood vessels in vitro, using primary human macrophages, gene and protein expression profiling, and tissue-engineered models of angiogenesis. 2) Determine the effects of pro-inflammatory pre-treatment on the regenerative effects of IL4- releasing biomaterials in vivo, using biomaterials that temporally control the phenotype of host macrophages in a murine hindlimb ischemia model. 3) Determine the angiogenic effects in vivo of a biomaterial-mediated macrophage cell therapy strategy that intracellularly directs a single population of macrophages from M1 to M2. This latter strategy may result in particularly beneficial biomaterials for patients who suffer from impaired leukocyte trafficking, including patients with diabetes, autoimmune disease, or those undergoing chemotherapeutic treatment for cancer. This work will advance our understanding of how biomaterials can be designed to leverage both the inflammatory and regenerative functions of macrophages to enhance angiogenesis, which will allow us to develop new strategies to treat numerous diseases characterized by pathological angiogenesis, including heart and brain ischemia, atherosclerosis, and diabetes, among many others. In addition, this project proposes a novel approach to direct tissue revascularization by controlling the actions of both recruited and exogenously administered macrophages using biomaterials.