P38alpha in Mouse Embryonic Stem Cells

描述（由申请人提供）：p38丝裂原活化蛋白（MAP）激酶是广泛表达的调节生长和发育的蛋白激酶。p38 α是在哺乳动物细胞中表达的最丰富的同种型。 根据细胞类型和刺激的性质，p38 α调节广泛的生理过程，如细胞增殖，存活和分化。其在胚胎发生中的关键作用在p38 α敲除（p38 a-/-）小鼠中得到最好的证明，其中胚胎显示有缺陷的血管化和血管结构，这表明p38 α在血管系统发育中的关键作用。p38 α基因敲除是致命的，因此从动物模型中可以获得的信息有限。然而，从敲除胚胎中分离的胚胎干细胞（ES细胞）（p38 α-/-ES细胞）是活的，这可以是分析p38 α特异性功能的有价值的细胞系统。 p38 α在体细胞中已被广泛研究，但我们对其在ES细胞中的功能知之甚少。我们已经表明，p38 a-/-ES细胞显示出一些改变的性质，从野生型ES细胞，包括细胞粘附，形态和活力。该提案的目标是：1。进一步鉴定几种p38 α和p38 α-/-ES细胞系，并确定p38 α缺失引起ES细胞性质改变的分子机制，2.研究p38 α在ES细胞分化中的作用，特别关注p38 α-/-ES细胞如何影响ES细胞向内皮细胞（EC）分化的能力，和3.通过体外三维血管生成模型分析ES细胞分化的EC功能。在该模型中，EC将在3D胶原基质中培养，在那里它们经历一系列形态学变化以形成管状结构，模仿体内血管形成的步骤。这种新的检测方法将被用作功能分析，以检验假设，即来自p38 a-/-ES细胞的EC可能保留一定的分化能力，但分化的细胞可能具有受损的功能，以组装成正常血管。这项研究有望提供良好的特点和遗传定义的pSSalpha缺陷ES细胞系，这将是特别有用的pSSalpha在ES细胞分化和血管发育中的作用的深入调查。从这项研究中获得的知识对于开发基于细胞的治疗方法来治疗与血管生成和心血管功能障碍相关的疾病可能很有价值。

DESCRIPTION (provided by applicant): p38 mitogen activated protein (MAP) kinases are widely expressed protein kinases that regulate growth and development. p38alpha is the most abundant isoform expressed in mammalian cells. Depending on cell types and the nature of stimuli, p38alpha regulates a wide range of physiological processes, such as cell proliferation, survival, and differentiation. Its pivotal role in embryogenesis is best demonstrated in p38alpha knockout (p38a-/-) mice where embryos display defective vascularization and vessel structures, suggesting a critical role of p38alpha in the development of vascular system. p38alpha knockout is lethal, thus limited information can be obtained from animal models. However, the embryonic stem (ES) cells isolated from knockout embryos (p38a-/-ES cells) are viable, which can be a valuable cell system to analyze the specific functions of p38alpha. p38alpha has been intensively studied in somatic cells, but we know little of its functions in ES cells. We have shown that p38a-/-ES cells display several altered properties from wild type ES cells, including cell adhesion, morphology and viability. The goals of this proposal are: 1. to further characterize several lines of p38a and p38a-/-ES cells and to determine the molecular mechanisms underlying the altered properties of ES cells caused by p38alpha deletion, 2. to investigate the role of p38alpha in ES differentiation, specifically focusing on how the ability of ES cells to differentiate to endothelial cells (ECs) is affected in p38a-/-ES cell, and 3. to analyze ES cell-differentiated EC function by an 3-dimendsional (3D) in vitro angiogenesis model. In this model, ECs will be cultured in a 3D collagen matrix, where they undergo a series of morphological changes to form tube-like structures, mimicking the steps of in vivo blood vessel formation. This novel assay will be used as a functional analysis to test hypothesis that ECs derived from p38a-/-ES cells may retain certain abilities to differentiate, but differentiated cells may have impaired functions to assemble into normal vessels. This study is expected to provide well characterized and genetically defined pSSalpha deficiency ES cell lines, which will be particularly useful for in-depth investigation of the roles of pSSalpha in ES cell differentiation and vascular development. The knowledge derived from this study could be valuable for the development of cell-based therapeutic approaches for diseases associated with angiogenesis and cardiovascular malfunction.