CARBON MONOXIDE AND VASCULAR SMOOTH MUSCLE CELL FUNCTION

描述(由申请人提供)：这项研究提案的广泛长期目标是建立由血红素加氧酶-1(HO-1)衍生的一氧化碳(CO)，作为一种新的、具有生物重要性的气体，调节血管损伤部位的动态平衡。我们测量了血管平滑肌细胞(SMC)CO的释放，发现SMC来源的CO分别以自分泌和旁分泌的方式抑制SMC的增殖和血小板的聚集。这一建议的中心假设是，HO-1衍生的CO是SMC对血管损伤反应的关键调节因子。为了验证我们的假设，我们计划追求以下三个相辅相成、相互关联的具体目标。在目标1中，我们将利用培养的血管SMC来研究CO在调节血管SMC迁移、胶原合成和血管内皮生长因子(VEGF)分泌中的作用。我们将研究外源性和内源性一氧化碳的影响。SMC将通过暴露室暴露于CO，而内源性CO的产生将通过腺病毒介导的HO-1基因转移来诱导。通过从HO-1基因敲除动物的主动脉中获取SMC并将其功能特性与野生型动物的SMC进行比较，还将研究HO-1来源的CO在调节SMC功能中的作用。如果发现一氧化碳改变了这些SMC功能，我们将确定cGMP或p38丝裂原活化蛋白激酶信号通路的参与。在目标2中，我们将利用HO-1基因缺陷的转基因小鼠来阐明HO-1在调节动脉损伤后胶原沉积和VEGF表达中的作用。此外，我们还将研究CO吸入是否可以替代HO-1来预防这些动物的胶原沉积和血管内皮生长因子的表达。在目的3中，我们将探索腺病毒介导的HO-1基因对这些动物体内胶原沉积和血管内皮生长因子表达的影响。最后，我们将确定CO介导的血管内皮生长因子释放是否以旁分泌的方式在体外和体内刺激内皮细胞的生长。预计这些研究将(A)确立CO作为一种新的血管壁损伤反应调节因子，以及(B)将HO-1/CO系统作为治疗血管纤维增生性疾病的一个有前景的新靶点。

DESCRIPTION (provided by applicant): The broad long-term objective of this research proposal is to establish heme oxygenase-1 (HO-1)-derived carbon monoxide (CO) as a novel and biologically important gas that regulates homeostasis at sites of vascular injury. We have measured the release of CO from vascular smooth muscle cells (SMC) and found that SMC-derived CO functions in an autocrine and paracrine fashion to inhibit SMC proliferation and platelet aggregation, respectively. The central hypothesis of this proposal is that HO-1-derived CO is a critical regulator of the SMC response to vascular injury. To test our hypothesis we plan to pursue the following three complementary and linked specific aims. In aim 1, we will examine the role of CO in regulating vascular SMC migration, collagen synthesis, and the secretion of vascular endothelial growth factor (VEGF) utilizing cultured vascular SMC. The effect of exogenously administered and endogenously derived CO will be studied. SMC will be exposed to CO via an exposure chamber while endogenous CO production will be induced by adenovirus-mediated transfer of the HO-1gene. The role of HO-1-derived CO in regulating SMC function will also be examined by harvesting SMC from the aorta of HO-1 knockout animals and comparing their functional properties with SMC from wild type animals. If CO is found to alter these SMC functions, we will determine the involvement of the cGMP or p38 mitogen activated protein kinase signaling pathways. In aim 2, we will elucidate the actions of HO-1 in regulating collagen deposition and VEGF expression following arterial injury using transgenic mice deficient in HO-1. In addition, we will investigate if CO inhalation can substitute for HO-1 in preventing collagen deposition and VEGF expression in these animals. In aim 3, we will explore the effect of adenovirus-mediated HO-1 gene delivery on collagen accumulation and VEGF expression in these animals. Finally, we will determine if CO-mediated VEGF release functions in a paracrine manner to stimulate endothelial cell growth both in vitro and in vivo. It is anticipated that these studies will (a) establish CO as a novel regulator of the vessel wall's response to injury and (b) implicate the HO-1/CO system as a promising new therapeutic target in treating vascular fibroproliferative disease.