Investigating deskmoplakin during vasculogenesis

性状（由申请方提供）：DP是细胞粘附连接（称为桥粒）的关键组分;然而，最近的研究表明DP在与桥粒分离的连接中的新位置，称为粘附复合物连接。这些连接发现于排列毛细血管的内皮细胞之间的接触部位。很少有研究关注DP在发育或肿瘤发生过程中新生毛细血管形成（血管发生）和分支（血管生成）中的功能。直到最近才开始研究确定DP的损失对胚胎发生期间毛细血管的影响（即，在DP-/-小鼠中）。因此，拟议研究的目标是确定DP在胚胎和肿瘤毛细血管形成过程中粘附复合体连接中的功能，并将这些知识应用于抑制肿瘤生长。初步证据表明，体内和体外桥粒斑蛋白的损失导致毛细血管渗漏和/或毛细血管去稳定化（Gallicano等人，2001年）。与胚胎发生一样，肿瘤发生高度依赖于血管发生和血管生成。没有毛细血管，胚胎就无法发育。同样地，没有毛细血管，肿瘤也不能发展或经历坏死，如果已经形成。基于本提案中描述的证据，假设在诱导型启动子的严格调控下，毛细血管内皮细胞内衬中DP的消融或突变将由于毛细血管网络的破坏而导致肿瘤抑制或坏死（如果已经形成）。提出了三个具体目标来检验这一假设。使用最近引入的工具和实验方法，将有可能在发育过程中识别不同的缺陷，并在胚胎（以及肿瘤）内操纵DP功能的激活或抑制，然后评估其对毛细血管形成和结构的影响。从这项研究中获得的知识将为发育和肿瘤生长过程中的血管和血管生成提供新的见解，并可能提供抑制肿瘤发生的新方法。

DESCRIPTION (provided by applicant): DP is a key component of cellular adhesion junctions known as desmosomes; however, recent investigations have demonstrated a novel location for DP in junctions separate from desmosomes termed complexes adherens junctions. These junctions are found at contact sites between endothelial cells that line capillaries. Few studies have focused on the function of DP in de novo capillary formation (vasculogenesis) and branching (angiogenesis) during development or tumorigenesis. Only recently have investigations begun to determine the affect the loss of DP has on capillaries during embryogenesis (i.e., in DP-/- mice). Consequently, the goal of the proposed research is to determine the function of DP in complexus adherens junctions during capillary formation in embryos and tumors, and apply that knowledge to inhibiting tumor growth. Preliminary evidence shows that the loss of desmoplakin both in vivo and in vitro results in leaky capillaries and/or capillary destabilization (Gallicano et al., 2001). Tumorigenesis, like embryogenesis, is highly reliant on both vasculogenesis and angiogenesis. Without capillaries, an embryo fails to develop. Likewise, without capillaries a tumor also fails to develop or undergoes necrosis if already formed. Based on evidence described in this proposal, it is hypothesize that under strict regulation by an inducible promoter either ablation of, or mutation of, DP in endothelial cells lining capillaries will result in tumor inhibition or necrosis (if already formed) due to the disruption of the capillary network. Three Specific Aims are proposed to test this hypothesis. Using recently introduced tools and experimental approaches, it will be possible to identify distinct defects during development and to manipulate activation or repression of DP function within the embryo (as well as in tumors) followed by assessment of their effects on capillary formation and structure. The knowledge gained from this research will provide novel insights into vasculo- and angiogenesis during developmental and tumor growth and possibly provide novel approaches for inhibiting tumorigenesis.