INTRACELLULAR SIGNALS MEDIATING SMOOTH MUSCLE CELL MIGRATION

介导平滑肌细胞迁移的细胞内信号

• 批准号: 6202317
• 负责人: BARBARA L HEMPSTEAD
• 金额: $ 28.8万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2000-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6202317
• 关键词: atherosclerotic plaque; biological signal transduction; cell migration; fibroblast growth factor; growth factor receptors; intracellular transport; neurotrophic factors; platelet derived growth factor; protein tyrosine kinase; receptor binding; tissue /cell culture; transfection; vascular smooth muscle

The intracellular mechanisms which are required to induce vascular smooth muscle cell migration and proliferation in response to injury are poorly understood. Although several receptor systems are capable of initiating smooth muscle cell migration and proliferation following the binding of ligand (bFGF, PDGF and most recently, NGF) the specific intracellular pathways which are activated by these receptor tyrosine kinases in vascular smooth muscle cells have yet to be characterized. Recent studies from our laboratory have demonstrated the expression of a novel growth factor/receptor system, the neurotrophins and their receptors, trk receptor tyrosine kinases and p75, in medial smooth muscle cells of both rat and human aorta and in cultured vascular human and rat smooth muscle cells. Moreover, their expression is exquisitely regulated during the development of vascular restenosis, as demonstrated by their expression in human atherosclerotic lesions and in the neointima which forms following balloon injury to the rat aorta. Finally, neurotrophins are potent mediators of vascular smooth muscle cell migration, in a response comparable to PDGF. The coexpression of the neurotrophins and trk receptors and their effect on smooth muscle cell migration suggests that these growth factors play an important role in regulating the response of smooth muscle cells to vascular injury. Trk is a receptor tyrosine kinase which has been shown to activate a number of intracellular signaling pathways in neuronal cells, such as the ras/MAP kinase pathway, phospholipase C (PLC-gamma) and phosphotidyl inositol 3-OH kinase (P13-kinase). The mechanisms of p75 intracellular signaling have not yet been defined, although an activation of sphingomyelinase and subsequent release of intracellular ceramide has recently been demonstrated by several laboratories. The overall aim of this grant proposal is to define the signaling pathways for smooth muscle cell migration in response to the neurotrophins. These pathways will be compared with those activated by the PDGF and bFGF receptors, to define those pathways which are required for the induction of vascular smooth muscle cell migration. Specifically, we intend to: I. Establish a vascular smooth muscle cell system to express trk receptors, as well as other receptor tyrosine kinases implicated in initiating vascular smooth muscle cell migration using gene transfer techniques. II. Identify the post-receptor pathways which mediate smooth muscle cell migration using cells which express trk, PDGF-beta and FGF-1 receptor tyrosine kinases. Mutant receptors, incapable of activating defined signaling enzymes, will be used to confirm that these specific pathways mediate cell migration. III. Examine the role of p75 receptor signal transduction in neurotrophin- mediated smooth muscle cell migration. These studies involve critical interactions with Dr. Gross, and Drs. Hajjar, Pomerantz, and Lander.

诱导血管顺畅所需的细胞内机制 肌肉细胞对损伤的迁移和增殖反应很差。 明白了。尽管有几个受体系统能够启动 血管内皮细胞结合后的迁移和增殖 特异性细胞内配体(碱性成纤维细胞生长因子、血小板衍生生长因子和最近的神经生长因子) 这些受体酪氨酸激酶激活的通路在 血管平滑肌细胞的特征尚未确定。最新研究 来自我们实验室的研究人员展示了一种新的生长方式 因子/受体系统、神经营养因子及其受体Trk 受体酪氨酸激酶和p75在两者的中膜平滑肌细胞中的表达 大鼠和人的主动脉及培养的人和大鼠的血管平滑肌 细胞。此外，它们的表达在过程中受到微妙的调节 血管再狭窄的发生，如它们在血管内皮细胞中的表达 人类动脉粥样硬化病变及随后形成的新生内膜 大鼠主动脉球囊损伤。最后，神经营养因子是有效的。 作为反应的血管平滑肌细胞迁移的介体 可与PDGF媲美。神经营养因子与Trk的共表达 受体及其在平滑肌细胞迁移中的作用提示 这些生长因子在调节细胞的反应中起着重要作用 平滑肌细胞对血管的损伤。 Trk是一种受体酪氨酸激酶，已被证明能激活一种 神经细胞内信号通路的数量，如 Ras/MAP激酶通路、磷脂酶C(PLC-γ)和磷脂酰肌醇 肌醇3-羟基激酶(P13-激酶)。P75在细胞内的作用机制 信令尚未定义，尽管激活 鞘磷脂酶和随后释放的细胞内神经酰胺 最近几个实验室证实了这一点。的总体目标 这项拨款提案是为了确定平滑肌肉的信号通路 神经营养因子作用下的细胞迁移。这些路径将是 与PDGF和bFGF受体激活的受体进行比较，以确定 那些诱导血管顺畅所需的通路 肌肉细胞迁移。具体地说，我们打算：一、建立一个 血管平滑肌细胞系统表达trk受体，以及 其他与启动血管平滑有关的受体酪氨酸激酶 使用基因转移技术的肌肉细胞迁移。二、找出 受体后通路介导血管内皮细胞迁移 表达trk、PDGF-β和成纤维细胞生长因子-1受体酪氨酸激酶的细胞。 突变的受体，不能激活特定的信号酶，将 用来证实这些特定的途径介导了细胞的迁移。 研究p75受体信号转导在神经营养因子中的作用 介导的平滑肌细胞迁移。这些研究涉及关键的 与格罗斯博士、哈贾尔博士、波美兰茨博士和兰德博士的互动。