PDE1C REGULATION OF VASCULAR SMOOTH MUSCLE PROLIFERATION

描述：动脉平滑肌细胞(SMC)通常处于 收缩的、非增殖的状态。动脉损伤可导致SMC 经历一次激活进入增殖状态。CAMP和cGMP抑制 增殖和SMC持续暴露于升高这些因子的制剂 因此，有必要加强cAMP和cGMP的降解。 研究人员假设，在人类SMC中，一种新的 必须诱导磷酸二酯酶(PDE1C)降解环核苷酸。 本应用侧重于确定PDE1C在SMC中的作用 扩散。调查人员建议对这一问题进行四个具体的研究 目标。 目标1提出的问题是，PDE1C是否仅限于增殖的SMC。 潜在的假设是PDE1C将在 在体外以及在正常和疾病过程中增殖的合成SMC 其特征是SMC增殖增加(动脉粥样硬化病变， 新生儿肺动脉高压、球囊血管成形术) 组织。相反，静止的细胞应该表达少量的PDE1C。 目标2阐述了细胞外基质在糖尿病中的潜在重要性 PDE1C的表达调控。动脉病变可能使SMC暴露于各种 细胞外基质的成分和初步研究表明 单体胶原可上调PDE1C，而纤维型胶原则不能 会有这样的效果。在这一目标中，调查人员将研究 不同成分的细胞外基质对PDE1C表达的影响。他们 也将决定p70S6激酶通路的作用，该通路已知 受细胞外基质的调节。 目标3将描述PDE1C启动子中哪些区域赋予敏感性 细胞外基质和由它们诱导的细胞内信号 矩阵。人SMC PDE1C及其启动子区域的克隆及序列分析 与报告构建体连接的截短启动子序列的产生 将提供有关调控PDE1C表达的序列的信息。 目标4将提出SMC是否需要PDE1C的问题 扩散。将使用药物抑制剂来抑制PDE1C 以及该酶的反义mRNA。SMC表型改变为 过表达PDE1C的细胞的增殖状态将被确定。 相反，PDE1C的抑制剂应该阻止SMC的增殖。

DESCRIPTION: Arterial smooth muscle cells (SMC) are ordinarily in a contractile, nonproliferative state. Arterial injury can cause SMC to undergo an activation into a proliferative state. cAMP and cGMP inhibit proliferation and SMC are constantly exposed to agents elevating these mediators, therefore enhanced degradation of cAMP and cGMP are necessary. The investigators have hypothesized that in human SMC, a new phosphodiesterase (PDE1C) must be induced to degrade cyclic nucleotides. This application focuses on determination of the role of PDE1C in SMC proliferation. The investigators propose to study this in four specific aims. Aim 1 asks the question whether PDE1C is restricted to proliferating SMC. The underlying hypothesis is that PDE1C will be highly expressed in proliferating, synthetic SMC in vitro and in normal and disease processes characterized by increased SMC proliferation (atherosclerotic lesions, neonatal pulmonary hypertension, balloon angioplasty) in human or ovine tissue. Conversely, quiescent cells should express little PDE1C. Aim 2 addresses the potential importance of the extracellular matrix in regulation of PDE1C expression. Arterial lesions may expose SMC to various components of the extracellular matrix and preliminary studies suggest monomer collagen can upregulate PDE1C, while fibrillar collagen does not have this effect. In this aim, the investigators will study the effect of various components of the extracellular matrix on PDE1C expression. They will also determine the role of the p70 S6 kinase pathway which is known to be regulated by extracellular matrix. Aim 3 will delineate what regions in the PDE1C promoter confer sensitivity to extracellular matrices and intracellular signals induced by these matrices. Cloning of the human SMC PDE1C and its promoter region and generation of truncated promoter sequences coupled to reporter constructs will provide information about sequences regulating PDE1C expression. Aim 4 will ask the question of whether PDE1C is required for SMC proliferation. PDE1C will be inhibited using pharmacologic inhibitors as well as antisense mRNA of the enzyme. Change in SMC phenotype to the proliferative state in cells overexpressing PDE1C will be determined. Inhibitors of PDE1C should conversely, prevent SMC proliferation.