NOS GENE TRANSFER IN PULMONARY HYPERTENSION

本建议的总体目的是审查以下两方面的平衡： 一氧化氮（NO）的产生和超氧化物介导的NG破坏， 正常和低氧/高血压肺循环， 为了建立用于肺内基因转移的目的基因， 高血压（PHTN）。 NO是一种重要的抑制性调节剂， 肺动脉张力和中膜平滑肌细胞增殖。 在PHTN发生发展过程中，内源性NO活性不足 完全对抗血管收缩和血管壁重塑。 这种NO活性的相对不足发生，尽管增加 内皮组成型一氧化氮合酶（eNOS）的表达， 提示反调节因子可能抑制内源性eNOS 或加速NO的破坏。一个重要的机制， NO可与超氧阴离子反应而被破坏。 该反应 超氧化物歧化酶（SOD）可预防。 我们假设 在PHTN的发展过程中，NOS和SOD活性不足可能 单独或组合导致次最大生物可利用NO， 导致肺血管收缩和血管壁重塑。 因此，我们建议检验肺动脉压降低的假设， NOS或SOD活性增强肺血管收缩作用 靶向缺失eNOS、诱导型（i）NOS、细胞外 （EC-SOD或Cu，Zn-SOD。 我们也将测试匡威的假设， 肺NO生成增加，肺血管收缩 在体内，通过NOS（eNOS或eNOS）的瞬时过表达而减弱， iNOS）和SOD（EC-SOD或Cu，Zn-SOD）。 表达将 通过注射肺亲和阳离子 脂质/DNA复合物。 使用敲除和 瞬时过表达的基因的兴趣，我们将更多 明确了NOS和SOD在调节脑缺血再灌注损伤中的作用。 PHTN的发展比以前可能使用 药理学方法。 虽然我们的重点包括详细的 一氧化氮合酶和超氧化物歧化酶在调节 肺血管张力，我们的总体目标是开发新的 治疗人类PHTN。 因此，检测NOS和/或SOD 过度表达减弱肺血管收缩将有助于两者， 鉴定用于PHTN“基因治疗”的潜在感兴趣基因， 同时也提供了肺血管基因 转移作为一种新的治疗方法值得将来的研究， PHTN。

The overall purpose of this proposal is to examine the balance between nitric oxide (NO) production and superoxide-mediated NG destruction in the normal and hypoxic/hypertensive pulmonary circulation, in an effort to establish genes of interest for gene transfer in pulmonary hypertension (PHTN). NO is an important inhibitory modulator of pulmonary artery tone and medial smooth muscle cell proliferation. During the development of PHTN, endogenous NO activity is insufficient to completely oppose vasoconstriction and vascular wall remodeling. This relative insufficiency of NO activity occurs despite increased expression of endothelial constitutive nitric oxide synthase (eNOS), suggesting that counter regulatory factors may inhibit endogenous eNOS or accelerate destruction of NO. An important mechanism through which NO may be destroyed is reaction with superoxide anion. This reaction can be prevented by superoxide dismutase (SOD). We hypothesize that during the development of PHTN, insufficient NOS and SOD activity may independently or in combination lead to submaximal bioavailable NO, resulting in pulmonary vasoconstriction and vascular wall remodeling. We therefore propose to test the hypothesis that reduction in pulmonary NOS or SOD activity will enhance pulmonary vasoconstriction using mice with targeted deletion of either eNOS, inducible (i)NOS, extracellular (EC-SOD, or Cu,Zn-SOD. We will also test the converse hypothesis, that pulmonary NO production can be augmented, and pulmonary vasoconstriction attenuated, in vivo, by transient overexpression of NOS (either eNOS or iNOS), and SOD (either EC-SOD or Cu,Zn-SOD). Expression will be targeted to pulmonary endothelium by injection of lung-avid cationic lipid/DNA complexes. Using the combined approaches of knockout and transient overexpression of the genes of interest, we will more definitively establish the roles of NOS and SOD in modulating the development of PHTN than has previously been possible using pharmacological approaches. While our focus includes a detailed physiological evaluation of the roles of NOS and SOD in modulating pulmonary vascular tone, our overall goal is development of novel therapies for humans with PHTN. Thus, testing if NOS and/or SOD overexpression attenuates pulmonary vasoconstriction will serve both to identify potential genes of interest for "gene therapy" for PHTN, as well as providing proof of principle that pulmonary vascular gene transfer could merit future study as a novel therapeutic approach in PHTN.