p38alpha and beta MAP Kinases in Endothelial Cells

描述（由申请人提供）：血管生成，即从先前存在的血管中形成新的毛细血管，是正常生理过程所必需的，如伤口愈合和胚胎发生。它也发生在病理条件下，如癌症、类风湿关节炎和某些心血管疾病。血管形成是一个复杂的过程，由血管生成因子和内皮细胞-基质相互作用激活的多种信号通路控制。p38 MAP激酶可被血管生成因子和细胞外基质蛋白激活。体内和体外研究表明，p38信号通路在血管生成的调控中起着重要作用。然而，所涉及的机制并没有很好地定义。本研究的目的是探讨内皮细胞（ECs）中表达的两种主要亚型p38 α和p38 β在调节参与血管生成的EC活性中的作用。为了实现这一目标，我们将通过腺病毒介导的基因靶向技术调节p38α和p38β的表达水平和激酶活性。p38 α和p38 β的具体功能将在两种不同的实验系统中进行评估：a)在二维（2D）细胞培养皿中，细胞增殖是内皮细胞的主要活动；b)在3D胶原基质中，内皮细胞分化成管状结构，模拟血管形成的步骤。本项目的具体目的是：1)验证血管生成因子（bFGF和VEGF）和胶原基质对p38alpha和p38beta的差异激活，并可能协同调节血管形成的假设；2)确定p38alpha和p38beta在EC增殖、存活和形态发生中的作用；3)验证p38通路在2D和3D细胞培养环境中可能作为增殖和分化的分子开关的假设。我们期望从两个不同的实验系统中获得的结果将是互补的，并导致更好地理解p38 α和p38 β在血管生成调节中的信号传导机制。这项研究可能为血管生成相关疾病的新型治疗药物的开发提供新的知识。

DESCRIPTION (provided by applicant): Angiogenesis, the formation of new blood capillaries from preexisting vessels, is essential for normal physiological processes, such as wound healing and embryogenesis. It also occurs under pathological conditions, such as cancer, rheumatoid arthritis, and certain cardiovascular diseases. Vessel formation is a complex event controlled by multiple signaling pathways activated by angiogenic factors and by endothelial cell-matrix interaction. p38 MAP kinases are activated by angiogenic factors and by extracellular matrix proteins. Both in vivo and in vitro studies have shown that the p38 signaling pathway plays important roles in the regulation of angiogenesis. However, the mechanisms involved are not well defined. The goal of this research is to investigate the roles for p38alpha and p38beta, two major isoforms expressed in endothelial cells (ECs), in the regulation of EC activities involved in angiogenesis. To accomplish this goal, we will modulate the expression level and kinase activity of p38alpha and p38beta by adenovirus-mediated gene targeting technique. The specific functions of p38alpha and p38beta will be assessed in two different experimental systems: a) in 2-dimensional (2D) cell dishes where cell proliferation is the major activity of ECs, and b) in 3D collagen matrices where ECs differentiate into tube-like structures, mimicking the steps of vessel formation. The specific aims of this project are: 1) to test the hypothesis that angiogenic factors (bFGF and VEGF) and collagen matrix differentially activate p38alpha and p38beta, which may coordinately regulate vessel formation, 2) to determine the roles of p38alpha and p38beta in EC proliferation, survival, and morphogenesis, and 3) to test the hypothesis that the p38 pathway may serve as a molecular switch between proliferation and differentiation in 2D and 3D cell culture environments. We expect that the results obtained from the two different experimental systems will be complementary and lead to a better understanding of the signaling mechanisms of p38alpha and p38beta in the regulation of angiogenesis. This investigation may provide new knowledge to the development of novel therapeutic drugs for diseases associated with angiogenesis.