ENDOTHELIAL CELL SENESCENCE GENES

这一延期申请要求支持研究所涉机制 在体外调节人内皮细胞衰老中的作用。 之前 从我们的实验室和其他人的观察已经确定， 内皮细胞生长受无信号肝素结合调节， 成纤维细胞生长因子（HBGF）原型，而人内皮细胞 静止受多肽细胞因子调节， （IL）-1 α。 最近的努力表明， IL-1 α的翻译显著延长了人类的寿命， 体外培养脐静脉内皮细胞（HUVEC）。 这些研究还 提示IL-1 α调节HUVEC的机制 衰老涉及信号序列少的IL-1的潜在功能， 1 α前体作为非末端的细胞内修饰剂 HUVEC分化途径。 因此，提出了两个具体目标， 进一步明确IL-1 α在HUVEC衰老中的作用。 第一个具体目标是研究这些问题的相关性。 观察其他类型的人内皮细胞在体外，是一个 这是我们先前研究成果的自然延伸。 这些研究 简单明了，包括使用细胞和分子方法来定义 体外人内皮细胞衰老与体内 供体的活体年龄。 因为IL-1 α是一种强有力的炎症信号， 在体内，这些研究可以提供有关基本机制的见解 调节老年人的血管疾病 第二个具体目标更具投机性，因为它受到我们的限制。 了解无信号细胞因子和生长因子的作用机制 来调节细胞功能 我们的长期目标是了解 无信号IL-1 α前体调节HUVEC功能。 使用分子 方法，我们建议确定一个假定的核易位信号 在前体的结构中。 此外，我们将努力 鉴定和表征细胞内多肽的结构， 能够与IL-1 α前体相互作用。 虽然我们建议， IL-1 α可能作为HUVEC静止的细胞内调节剂， 衰老，我们也认识到，一个替代的分泌途径， 我们建议利用我们最近的观察来研究这个问题， 热诱导的结合蛋白可以作为一种媒介物， HBGF-1。 我们预计，这些努力可能会提供深入了解 细胞内IL-1 α调节人内皮细胞的机制 体外细胞衰老，并帮助我们理解的贡献， 血管系统对体内衰老过程的影响，特别是当 病理生理学被炎症和血管生成夸大。

This renewal application requests support to study the mechanisms involved in the regulation of human endothelial cell senescence in vitro. Prior observations from our laboratory and others have established that human endothelial cell growth is regulated by the signal-less heparin-binding fibroblast growth factor (HBGF) prototypes while human endothelial cell quiescence is regulated by polypeptide cytokines including interleukin (IL)-1alpha. Recent efforts have suggested that the repression of translation of IL-1alpha significantly extends the lifespan of the human umbilical vein endothelial cell (HUVEC) in vitro. These studies also suggest that the mechanism utilized by IL-1alpha to regulate HUVEC senescence involves the potential function of the signal sequence-less IL- 1alpha precursor to act as an intracellular modifier of the non-terminal HUVEC differentiation pathway. Thus, two specific aims are proposed to further define the role of IL-1alpha in HUVEC senescence. The first specific aim proposes to study the relevance of these observations to other types of human endothelial cells in vitro and are a natural extension of our prior research effort. These studies are straightforward and include the use of cell and molecular methods to define correlates between human endothelial cell senescence in vitro and the in vivo age of the donor. Because IL-1alpha is a potent inflammatory signal in vivo, these studies may provide insight into basic mechanisms involved in the regulation of vascular disease in the elderly. The second specific aim is more speculative because it is limited by our knowledge of the mechanism used by signal-less cytokines and growth factors to regulate cellular function. Our long-term goal is to understand how the signal-less IL-1alpha precursor regulates HUVEC function. Using molecular methods, we propose to identify a putative nuclear translocation signal within the structure of the precursor. In addition, we will attempt to identify and characterize the structure of intracellular polypeptides that are able to interact with the IL-1alpha precursor. While we suggest that IL-1alpha may act as an intracellular modifier of HUVEC quiescence and senescence, we also recognize that an alternative secretory pathway may exist and we propose to study this issue using our recent observation that heat-induced binding proteins may act as a vehicle for the secretion of HBGF-1. We anticipate that these efforts may provide insight into the mechanism(s) used by intracellular IL-1alpha to regulate human endothelial cell senescence in vitro and aid our understanding of the contribution of the vasculature to the aging process in vivo especially when the pathophysiology is exaggerated by inflammation and angiogenesis.