Hematopoietic stem cell cytokine control of developmental vascularization

描述（由申请人提供）：在这个新提案中，我们研究了我们的新发现，即造血干细胞细胞因子（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-11）的独特组合在确定的无血清条件下（和不含phorbol酯的情况下）在3D胶原基质中控制人内皮细胞（EC）管的形态发生和EC-周细胞管的组装。有趣的是，VEGF本身没有影响，需要这些造血因子的协同作用才能对EC发芽产生影响，这是其主要的形态发生影响。我们提出假设，SCF， IL-3和SDF-11是血管形态发生的关键调节因子，它们以协同方式起作用，并且是已知发育血管形成介质（例如VEGF和BMP-4）作用的必要辅助因子。联合使用c-Kit （SCF受体）和CXCR4 （SDF-11受体）抑制剂或SCF和IL-3阻断抗体可导致发育中的鹌鹑胚胎血管出血表型，这与血管形成和重塑缺陷有关。此外，我们发现这三个因子协同激活Src， B-Raf和Erk激酶，并诱导1221整合素和Pak2的表达，这是已知的血管形态发生的调节因子。我们将阐明这三种细胞因子在内皮细胞中信号协同作用的分子基础，这些因子如何与VEGF、BMP-4和周细胞结合来控制内皮细胞的发芽，以及它们如何在体外和体内的管共组装和成熟过程中影响内皮细胞和周细胞。我们提出三个具体目标：明确目标#1。阐明SCF、IL-3和SDF-11在三维细胞外基质中协同刺激血管源性EC管组装的信号机制。具体目标2。确定SCF、IL-3和SDF-11如何影响VEGF和BMP-4信号，从而控制3D细胞外基质中EC的发芽反应。具体目标#3。确定SCF、IL-3和SDF-11如何调节三维细胞外基质中周细胞诱导的EC发芽反应和血管源性EC-周细胞管共组装。

DESCRIPTION (provided by applicant): 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-11) control human endothelial cell (EC) tube morphogenesis and EC-pericyte tube co assembly 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-11 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-11 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 1221 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 co assembly 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-11 synergize to stimulate vasculogenic EC tube assembly in 3D extracellular matrices. Specific Aim #2. To determine how SCF, IL-3 and SDF-11 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-11 act to regulate pericyte-induced EC sprouting responses and vasculogenic EC-pericyte tube co assembly in 3D extracellular matrices. PUBLIC HEALTH RELEVANCE: This work focuses on the ability of factors which are known to support the growth of immature blood cells to also be able to support the formation of blood vessels which carry blood cells. These factors bind to endothelial cells, which line blood vessels and to pericytes, a supporting cell that helps blood vessels form and become stable. A basic understanding of the mechanisms underlying how blood vessels form and become stabilized is critical in efforts to stimulate or inhibit the process in the context of various human diseases such as cardiovascular disease, diabetes or cancer.