THE ROLE OF CARBON MONOXIDE IN VASCULAR HOMEOSTASIS

描述 （摘自申请人摘要）研究的长期目标是 深入了解血管张力和结构是如何在 细胞和分子水平。 重要见解的发病机制 破坏血管稳态的疾病，如动脉粥样硬化， 肺动脉高压，将通过阐明细胞和 分子血管稳态机制。 复杂的电路， 已知血管细胞相互作用和反馈调节回路控制 血管张力和结构。 这一提议的核心假设是， 血管系统中内源性一氧化碳（CO）的产生 是对缺氧的适应性反应 内源性CO主要是 血红素加氧酶（HO）的酶活性的产物。 诱导型 这种酶的一种，HO-1，由缺氧的血管平滑肌细胞表达， 在血管系统中释放CO的SMC。 平滑肌细胞来源的CO可能 以自分泌和旁分泌方式影响血管细胞功能。 申请人 建议使用细胞研究CO在血管稳态中的作用， 培养和转基因动物技术。 建议的具体目标 主要研究内容有：（1）CO调控基因表达的分子机制 表达（ii）以确定SMC衍生的CO在内皮-平滑肌细胞中的作用。 肌肉细胞的相互作用，在设置缺氧和（iii）以验证 CO在体内肺血管张力和结构调节中的作用。 实验设计涉及使用体外单细胞类型和共- 培养系统与HO-1的调节过表达结合， 转染的SMC。 待研究的内皮细胞功能方面包括 基因表达、增殖和屏障功能。 同样，SMC基因 表达、生长和对促有丝分裂刺激的增殖反应将是 考察 将使用转基因小鼠模型方法来检查 在体低氧肺血管动态平衡中CO的作用。 人类 表面活性剂蛋白-C（SP-C）启动子将用于靶向表达 将HO-1转基因导入肺，并评估动物的肺功能。 缺氧引起的肺动脉高压。 上述 研究应加强对血管内稳态的理解， 的CO。

DESCRIPTION (Adapted from applicant's abstract) The long term goal of the research is to gain insight into how vascular tone and structure are regulated at the cellular and molecular level. Important insights into the pathogenesis of diseases of disrupted vascular homeostasis, such as atherosclerosis and pulmonary hypertension, would be gained by an elucidation of the cellular and molecular vascular homeostatic mechanisms. Complex circuits involving vascular cell interactions and feedback regulatory loops are known to control vascular tone and structure. The central hypothesis of this proposal is that the production of endogenous carbon monoxide (CO) in the vasculature represents an adaptive response to hypoxia. Endogenous CO is largely the product of the enzymatic activity of heme oxygenase (HO). The inducible form of this enzyme, HO-1, is expressed by hypoxic vascular smooth muscle cells (SMCs) which release CO in the vasculature. Smooth muscle cell-derived CO may affect vascular cell function in autocrine and paracrine ways. The applicant proposes to investigate the role of CO in vascular homeostasis using cell culture and transgenic animal techniques. The specific aims of the proposed project are: (I) to study the molecular mechanisms by which CO regulates gene expression (ii) to determine the role of SMC-derived CO in endothelial-smooth muscle cell interactions in the setting of hypoxia and (iii) to validate the role of CO in the regulation of pulmonary vascular tone and structure in vivo. The experimental design involves use of in vitro single-cell type and co- culture systems in conjunction with regulated overexpression of HO-1 by transfected SMCs. Aspects of endothelial cell function to be studied include gene expression, proliferation and barrier function. Similarly, SMC gene expression, growth and proliferative response to mitogenic stimuli will be examined. A transgenic mouse model approach will be used to examine the role of CO in pulmonary vascular homeostasis under hypoxia in vivo. The human Surfactant Protein-C (SP-C) promoter will be used to target expression of the HO-1 transgene to the lung and the animals will be assessed as to the development of pulmonary hypertension in response to hypoxia. The above studies should enhance the understanding of vascular homeostasis and the role of CO.