MECHANISMS OF ENDOTHELIAL CELL-COLLAGEN INTERACTIONS

血管生成依赖于适当的胶原生物合成和交联剂，而且，I型 胶原是一种理想的体外血管生成支架。尽管如此，I型胶原介导的机制 血管生成仍然知之甚少。我们建议定义类型/胶原纤维的特征， 内皮细胞表面和细胞内共同作用的信号通路，介导I型胶原- 诱导血管生成。我们开发了一种独特的模型来研究血管内皮细胞形态发生。 体外培养。我们使用我们的系统的初步数据支持C2B1和C2B1之间的假设 整合素受体和整合素结合序列导致D38MAPK激活，以及 内皮细胞形态发生过程中粘着斑激酶的失活。我们将在以下方面测试这一假设 目的如下：L)确定内皮细胞表面A1_1、A2111和C_V_3整合素受体的作用， 通过检测整合素或纤维连接蛋白的功能阻断活性来检测蛋白多糖和纤维连接蛋白的活性 GAG功能的抗体和抑制物在血管生成中的作用；2)合成三螺旋I型胶原 模拟肽(THP)，包括可能的整合素结合位点，并研究其抑制细胞生长的能力。 胶原附着，结合整合素受体，并影响血管生成；3)研究 整合素功能阻断抗体、整合素结合THPS和化学和显性负性结构 信号通路的抑制剂对p38MAPK和FAK的激活和血管生成的作用；以及4)检测 C_1整合素连接离散的胶原序列，以及p38MAPK和FAK通路，a)在 在鸡的CAM体内，以及b)在包括异型胶原在内的其他聚合物诱导血管生成中 纤维和纤维蛋白。我们的工作将定义I型胶原的结构特征，这些结构特征对其形态发生活性至关重要， 探讨O_2_1整合素-胶原连接、p38 MAPK和FAK激活之间的功能联系 血管生成，并有助于理解和治疗人类涉及血管的疾病 不充分，如缺血或不正常的血管生成，如在肿瘤生长中。

Angiogenesis depends upon proper collagen biosynthesis and crosslinking, moreover, type I collagen is an ideal scaffold for angiogenesis in vitro. Despite this, mechanisms of type I collagen-mediated angiogenesis remain poorly understood. We propose to define the features of the type / collagen fibril, endothelial cell surface, and intracellutar signaling pathways that act together to mediate type I collagen- induced angiogenesis. We have developed a unique model for studying endothelial tube morphogenesis in vitro. Our oreliminary data using our system sUPport the hypothe_i_ that engagement between the c_2B1 integrin receotor and integrin-binding sequences of _pe I collagen result in D38MAPK activation, and inactivation of Focal Adhesion Kinase during endothelial tube morphogenesis. We will test this hypothesis in the following aims:l) Define the roles of endothelial cell surface a1_1, a2111, and c_V_3 integrin receptors, sulfated proteoglycans, and fibronectin by testing the activities of integrin or fibronectin function-blocking antibodies and inhibitors of GAG function on angiogenesis; 2) Synthesize triple helical, type I collagen mimetic peptides (THPs) including putative integrin-binding sites, and study their capacities to inhibit cell- collagen attachment, bind integrin receptors, and influence angiogenesis; 3) Study the consequences of integrin function-blocking antibodies, integrin-binding THPs, and chemical and dominant-negative construct inhibitors of signaling pathway function on p38MAPK and FAK activation and angiogenesis; and 4) Examine the role of c_2_1 integrin ligation of discrete collagen sequences, and the p38MAPK and FAK pathways, a) in vivo in the chick CAM, and b) in angiogenesis induction by other polymers including heterotypic collagen fibrils and fibrin. Our work will define the type I collagen structural features critical for its morphogenic activity, probe the functional link between o_2_1 integrin-collagen ligation, p38 MAPK and FAK activation, and langiogenesis, and contribute to the understanding and treatment of human diseases involving vascular insufficiencies, such as ischemia, or abnormal angiogenesis, as in tumor growth.