Notch Signaling in Lymphangiogenesis

描述（由申请人提供）：Notch途径是一种保守的信号传导机制，其功能是调节细胞命运决定。该提案的总体目标是确定Notch在淋巴重塑和肿瘤淋巴管生成期间的细胞命运决定中的作用。我们的一般假设是，Notch活性是必要的，以协助淋巴重塑。我们假设不同的Notch家族成员在淋巴生长和发育中的独特作用，重点是Notch 1，Notch 3和Notch 4。我们已经发现，VEGFR-3，一种淋巴调节因子，受Notch 1和Notch 4的转录调控。相比之下，Notch对Prox-1的复杂调控被发现，Notch 1和Notch 4的作用相反。我们的总体策略将使用体外淋巴管生成测定和小鼠建模的组合来确定改变淋巴管内皮细胞中Notch活性的后果。此外，我们的初步研究表明Notch是肿瘤淋巴管生长的调节因子，也是控制肿瘤血管和淋巴管中VEGFR-3表达的因子。在目的I中，我们评估了Notch在分离的淋巴管内皮细胞中的功能，目的是确定Notch对VEGFR-3和Prox 1的调节是否是淋巴管内皮细胞行为的关键。在Aim II中，我们将分析Notch突变小鼠并在真皮淋巴管内皮细胞中激活Notch，以确定Notch是否促进淋巴管生成、淋巴重塑或淋巴完整性。在Aim III中，我们使用实验室开发的Notch抑制剂，一种配体依赖性Notch信号传导的分泌型拮抗剂，来评估VEGF-C介导的肿瘤淋巴管生成是否需要Notch。我们的总体目标是研究发育性和病理性淋巴管生成，以更好地了解Notch在淋巴管生成中的作用。公共卫生相关性：Notch信号传导是血管正常发育的基础。我们目前的数据强烈暗示Notch作为淋巴发育和病理的调节剂。因此，我们提案中概述的研究将有助于我们了解Notch在淋巴分化中的功能，并可能对开发纠正淋巴疾病或阻断肿瘤淋巴管生成的策略和治疗方法至关重要。

DESCRIPTION (provided by applicant): The Notch pathway is a conserved signaling mechanism that functions to modulate cell- fate decisions. The overall objectives of this proposal are to define roles for Notch in cell- fate determination during lymphatic remodeling, and tumor lymphangiogenesis. Our general hypothesis is that Notch activity is necessary to assist in lymphatic remodeling. We hypothesize unique roles for different Notch family members in lymphatic growth and development, with a focus on Notch1, Notch3, and Notch4. We have discovered that VEGFR-3, a lymphatic regulator, is transciptionally regulated by Notch1 and Notch4. In contrast, a complex regulation of Prox-1 by Notch was uncovered with opposing roles for Notch1 and Notch4. Our general strategy will use a combination of in vitro lymphangiogenesis assays and mouse modeling to define the consequences of altering Notch activity in lymphatic endothelial cells. In addition, our preliminary studies implicate Notch as a regulator of tumor lymphatic growth and a factor controlling VEGFR-3 expression in tumor vessels and lymphatics. In Aim I, we evaluate Notch function in isolated lymphatic endothelial cells with the goal of determining if Notch regulation of VEGFR-3 and Prox1 is key to lymphatic endothelial cell behavior. In Aim II, we will analyze Notch mutant mice and activate Notch in dermal lymphatic endothelial cells to determine if Notch promotes lymphangiogenesis, lymphatic remodeling or lymphatic integrity. In Aim III, we use a Notch inhibitor developed in the lab, a secreted antagonist of ligand-dependent Notch signaling, to evaluate if VEGF-C-mediated tumor lymphangiogenesis requires Notch. Our overall goal is to study both developmental and pathological lymphangiogenesis to better understand Notch function in lymphatics. PUBLIC HEALTH RELEVANCE: Notch signaling is fundamental to proper vascular development. We present data strongly implicating Notch as a regulator of lymphatic development and pathologies. Thus, the studies outline in our proposal will aid us in understanding the functions of Notch in lymphatic differentiation and may be critical to developing strategies and therapeutics to correct lymphatic disorders or block tumor lymphangiogenesis.