The Role of Cyclooxygenase 2 in Mechanical Stress-Induced Lung Injury

描述(由申请人提供)：本KOS申请的目标是提供必要的技能和经验，使首席调查员成为一名成功的、独立的内科科学家。本提案旨在明确环氧合酶2(C0X2)在急性肺损伤(ALI)的病理生理学和治疗中的作用。ALI是一种毁灭性的临床综合征，每年影响20多万患者，死亡率为30%-50%。虽然机械通气是治疗ALI的主要方法，但机械通气，尤其是高潮气量的机械通气，会加重现有的损伤，甚至引起新的肺损伤，这种现象被称为呼吸机诱导的肺损伤(VILI)。C0X2是一种诱导性酶，已知与急性炎症和血管通透性增加有关。然而，关于C0X2在机械应激反应中的表达及其在机械应激诱导的肺损伤中的作用，目前还知之甚少。首席调查员提供的初步数据表明，C0X2是VILI的候选基因，表明C0X2的表达增加与高潮气量机械通气引起的肺部炎症和血管屏障破坏有关。此外，C0X2的药理抑制具有保护作用，可减少急性炎症和增强通透性。我们推测，C0X2的表达是对大潮气量机械通气的反应，并在VILI伴随的急性炎症和内皮屏障破坏中发挥重要作用。我们还假设，给予选择性的C0X2抑制剂可以减弱或预防VILI。首席研究人员建议使用体内和体外模型来探索C0X2在机械应激诱导的肺损伤中的确切作用机制。在SA#1中，我们将描述C0X2在已建立的VILI小鼠模型中的作用，该模型将C0X2的表达和前列腺素类物质的产生与损伤的生化和组织学指标相关联，并探索00X2对机械应激的调节。SA#2将专注于周期性拉伸，这是一种独特的机械应激诱导肺损伤的体外模型。利用内皮细胞阻力、免疫组织化学、蛋白质生化、siRNA、实时/RT-POR和Western blotting等方法，我们将确定00X2在周期性应激诱导的细胞骨架重组中的作用。在SA#3中，使用药物抑制和基因沉默技术，确定VILI中局部和全身00X2抑制的有效性。相关性(参见说明)；急性肺损伤(ALI)是一种毁灭性的综合征，在美国每年导致超过7.4万名患者死亡，治疗方案很少。ALI患者需要机械通气，但其本身可导致或加重肺损伤。研究机械应激对肺的影响对于更好地了解这种综合征和开发新的治疗方法是必要的。(摘要结束)

DESCRIPTION (provided by applicant): The goal of this KOS application is provide the essential skills and experience that will allow the Principal Investigator to become a successful, independent physician-scientist. This proposal seeks to define a role for cyclooxygenase 2 (C0X2) in the pathophysiology and treatment of acute lung injury (ALI). ALI is a devastating clinical syndrome that affects more than 200,000 patients per year, with a mortality of 30-50%. Although a mainstay of therapy for ALI, mechanical ventilation, especially with high tidal volumes, can worsen existing injury or even cause de novo lung injury, a phenomenon referred to as ventilator induced lung inury (VILI). C0X2 is an inducible enzyme known to be involved in acute inflammation and increased vascular permeability. However, little is known about the expression of C0X2 in response to mechanical stress and its involvement in mechanical stress-induced lung injury. Preliminary data generated by the Principal Investigator have identified C0X2 as a candidate gene in VILI, demonstrating increased expression of C0X2 associated with increased lung inflammation and vascular barrier disruption in response to high tidal volume mechanical ventilation. Additionally, pharmacologic inhibition of C0X2 is protective, decreasing acute inflammation and enhanced permeability. We hypothesize that C0X2 expression is induced in response to high tidal volume mechanical ventilation and plays an important role in the acute inflammation and endothelial barrier disruption that accompanies VILI. We additionally hypothesize that the administration of selective C0X2 inhibitors may attenuate or prevent VILI. The Principal Investigator proposes to explore the precise mechanisms of action of C0X2 in mechanical stress-induced lung injury, using both in vivo and in vitro models. In SA #1, we will characterize the role of C0X2 in a well established, murine model of VILI correlating C0X2 expression and prostanoid production with biochemical and histologic indices of injury and exploring the regulation of 00X2 in response to mechanical stress. SA #2 will focus on cyclic stretch, a unique in vitro model of mechanical stress-induced lung injury. Using measures of endothelial resistance, immunohistochemistry, protein biochemistry, sIRNA, real time/RT-POR, and Western blotting, we will define the role of 00X2 in cyclic stress-induced cytoskeletal reorganization. In SA #3, define the efficacy of local and systemic 00X2 inhibition in VILI, using pharmacologic inhibition and gene silencing techniques. RELEVANCE (See instructions); Acute lung injury (ALI) is a devastating syndrome that kills more than 74,000 patients each year in the US and has very few therapeutic options. Mechanical ventilation is required for patients with ALI, however can itself cause or worsen lung injury. Research into the effect of mechanical stress on lung from ventilation are necessary to better understand this syndrome and to develop new treatments. (End of Abstract)