Hematopoietic stem cell cytokine control of developmental vascularization

在这个新的提议中，我们研究了我们的新发现， 细胞因子（即干细胞因子-SCF、白细胞介素3- IL-3和基质衍生因子-1 α- SDF-1？） 对照人内皮细胞（EC）管形态发生和EC-周细胞管共组装 在3D胶原基质中定义的无血清条件下（并且在不存在佛波醇酯的情况下）。 有趣的是，VEGF本身没有影响，需要这些造血因子的协同作用 以影响EC发芽，其主要形态发生影响。我们提出假设， SCF、IL-3和SDF-1是血管形态发生的关键调节因子，它们以协同方式发挥作用， 是已知的发育性血管形成介质（例如VEGF和 BMP-4）。联合给予c-Kit（SCF受体）和CXCR 4（SDF-1受体）抑制剂，或 阻断SCF和IL-3抗体导致鹌鹑胚胎血管出血表型 与血管形成和重塑的缺陷有关。此外，我们表明，这三个因素协同作用， 激活Src、B-Raf和Erk激酶并诱导已知的整合素和Pak 2的表达 血管形态发生的调节因子。我们将阐明信号协同作用的分子基础， EC中的三种细胞因子，这些因子如何与VEGF，BMP-4和周细胞相互作用以控制EC发芽 以及它们在体外和体内的管共组装和成熟事件期间如何影响EC和周细胞。 我们提出了三个具体目标，即： 具体目标#1。阐明SCF、IL-3和SDF-1协同作用的信号机制， 在3D细胞外基质中刺激血管生成EC管组装。 具体目标#2。为了确定SCF，IL-3和SDF-1是如何影响VEGF和BMP-4信号传导的， 3D细胞外基质中的EC发芽反应。 具体目标#3确定SCF、IL-3和SDF-1是如何调节周细胞诱导的EC的 3D细胞外基质中的出芽反应和血管生成EC-周细胞管共组装。

In this new proposal, we investigate our novel finding that a unique combination of hematopoietic stem cell cytokines (i.e. stem cell factor-SCF; interleukin 3- IL-3; and stromal-derived factor-1 alpha- SDF-1¿) control human endothelial cell (EC) tube morphogenesis and EC-pericyte tube coassembly under defined serum-free conditions (and in the absence of phorbol ester) in 3D collagen matrices. Interestingly, VEGF has no influence by itself and requires the synergistic action of these hematopoietic factors in order to exert an effect on EC sprouting, its major morphogenic influence. We propose the hypothesis that SCF, IL-3 and SDF-1¿ are critical regulators of vascular morphogenesis which act in a synergistic manner and are necessary cofactors for the action of known mediators of developmental vascularization (e.g. VEGF and BMP-4). Combined administration of c-Kit (the SCF receptor) and CXCR4 (the SDF-1¿ receptor) inhibitors or blocking antibodies to SCF and IL-3 leads to vascular hemorrhage phenotypes in developing quail embryos that relates to defects in vessel formation and remodeling. Also, we show that the three factors synergize to activate Src, B-Raf and Erk kinases and induce the expression of the ¿2¿1 integrin and Pak2 which are known regulators of vascular morphogenesis. We will elucidate the molecular basis for the signaling synergism of the three cytokines in ECs, how these factors interface with VEGF, BMP-4, and pericytes to control EC sprouting and how they affect both ECs and pericytes during tube coassembly and maturation events in vitro and in vivo. We propose three specific aims which are; Specific Aim #1. To elucidate the signaling mechanisms by which SCF, IL-3 and SDF-1¿ synergize to stimulate vasculogenic EC tube assembly in 3D extracellular matrices. Specific Aim #2. To determine how SCF, IL-3 and SDF-1¿ affect VEGF and BMP-4 signaling to control EC sprouting responses in 3D extracellular matrices. Specific Aim #3. To determine how SCF, IL-3 and SDF-1¿ act to regulate pericyte-induced EC sprouting responses and vasculogenic EC-pericyte tube coassembly in 3D extracellular matrices.