REGULATION OF CELL CYCLE PROTEINS DURING ANGIOGENESIS

血管生成在许多过程中起着重要作用，如发育、伤口愈合和肿瘤形成。尽管内皮细胞(EC)增殖是血管生成中的一个关键事件，但对这一过程中至关重要的分子的调控知之甚少。我们推测，1)控制细胞周期G1转换的细胞周期蛋白在血管生成过程中受到调节，2)一些抑制EC生长的抗血管生成剂影响对G1进程至关重要的蛋白质。我们还假设3)细胞外基质环境在调控EC生长中是重要的，4)不同的整合素受体在这一过程中负责触发细胞周期蛋白。为了研究这些假说，我们将在体内和体外监测EC增殖过程中的G1期细胞周期蛋白。首先，我们将通过引入端粒酶来建立寿命延长的微血管内皮细胞系。我们将利用这些细胞来确定1)在丝裂原诱导的EC增殖过程中，哪些细胞周期蛋白在不同的基质蛋白上表达；2)鉴定涉及的整合素；3)确定整合素的激活如何影响细胞周期蛋白；4)研究抗血管生成药物处理后的细胞周期事件。此外，我们还将确定G1期细胞周期蛋白在体内血管生成过程中的表达模式。我们还通过检测细胞周期蛋白缺失的小鼠来研究这些蛋白在血管生成中的作用。这项研究的数据将为整合素诱导的细胞周期进程的机制和细胞周期蛋白在血管生成中的作用提供具体的见解。了解抗血管生成剂的作用机制以及结扎和细胞周期机制之间的分子联系将有助于开发控制血管生成相关病理的新方法。

Angiogenesis plays a fundamental role in a number of processes such as development, wound healing and tumorigenesis. Although endothelial cell (EC) proliferation is a key event in angiogenesis, little is known about the regulation of molecules critical for this process. We postulate that 1) cell cycle proteins that control G1 transition of the cell cycle are regulated during angiogenesis and 2) some anti-angiogenic agents that inhibit EC growth affect proteins critical for G1 progression. We also postulate that 3) the extracellular matrix environment is important in regulating EC growth and that 4) distinct integrin receptors are responsible for triggering cell cycle proteins during this process. To investigate these hypotheses, we will monitor G1 phase cell cycle proteins during EC proliferation in vivo and in vitro. Initially we will establish a microvascular EC line with expanded life span by introducing telomerase. We will use these cells to determine 1) what G1 cell cycle proteins are expressed during mitogen-induced EC proliferation on different matrix proteins; 2) identify the integrins involved; 3) determine how integrin activation affects cell cycle proteins; 4) investigate the cell cycle events following treatment with anti-angiogenic agents. Furthermore, we will determine the expression patterns of G1 cell cycle proteins during angiogenesis in vivo. We also investigate the role of these proteins in angiogenesis by examining mice null for cell cycle proteins. Data derived from this study should provide specific insights to the mechanism of integrin-induced cell cycle progression and the role of cell cycle proteins during angiogenesis. Understanding the mechanism of anti-angiogenic agents and the molecular links between ligation and cell cycle machinery will aid in the development of new approaches to control angiogenesis-associated pathologies.