ENDOTHELIAL CELL SENESCENCE GENES

此续订申请请求支持以研究涉及的机制 在体外对人内皮细胞衰老的调控。之前 来自我们实验室和其他人的观察已经证实，人类 内皮细胞的生长受无信号肝素结合的调节 成纤维细胞生长因子(HBGF)的原型，而人内皮细胞 静息受包括白介素类在内的多肽细胞因子的调节 (IL)-1α。最近的努力表明，对 翻译IL-1α显著延长了人类的寿命 体外培养脐静脉内皮细胞(HUVEC)。这些研究还包括 提示IL-1α调节人脐静脉内皮细胞的机制 衰老涉及信号序列缺失的IL-1的潜在功能 1α前体作为非末端的细胞内修饰物 HUVEC分化途径。因此，提出了两个具体目标，以 进一步明确IL-1α在人脐静脉内皮细胞衰老中的作用。 第一个具体目标建议研究这些因素的相关性 对体外培养的其他类型的人内皮细胞的观察 这是我们先前研究工作的自然延伸。这些研究是 简单明了，包括使用细胞和分子方法来定义 体外培养的人内皮细胞衰老与血管内皮细胞的相关性 捐献者的活体年龄。因为IL-1α是一种强有力的炎症信号 在活体内，这些研究可能提供对涉及的基本机制的洞察 在调节老年人的血管疾病方面。 第二个具体目标更具投机性，因为它受到我们的 对无信号细胞因子和生长因子的作用机制的认识 来调节细胞功能。我们的长期目标是了解 无信号IL-1α前体调节HUVEC功能。使用分子 方法，我们建议识别一个假定的核转位信号 在前驱体的结构中。此外，我们还将尝试 鉴定和鉴定胞内多肽的结构 能够与IL-1α前体相互作用。虽然我们建议 IL-1α可作为HUVEC静息的细胞内修饰物 衰老，我们也认识到另一种分泌途径可能 存在，我们建议利用我们最近的观察来研究这个问题 热诱导结合蛋白可能作为一种载体分泌 HBGF-1。我们预计，这些努力可能会提供对 细胞内IL-1α调节人内皮细胞的机制(S) 细胞在体外衰老的作用，有助于我们理解 血管系统对体内衰老过程的影响，尤其是当 炎症和血管生成夸大了病理生理学。

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.