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

描述（由申请人提供）：这个KOS申请的目标是提供必要的技能和经验，使首席研究员成为一个成功的，独立的医师-科学家。本提案旨在确定环氧化酶2 （C0X2）在急性肺损伤（ALI）的病理生理和治疗中的作用。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%。虽然机械通气是急性肺损伤的主要治疗手段，但机械通气，特别是在高潮气量时，会加重现有损伤，甚至引起新发肺损伤，这种现象被称为呼吸机诱导肺损伤（VILI）。C0X2是一种诱导酶，已知参与急性炎症和血管通透性增加。然而，关于C0X2在机械应力下的表达及其在机械应力诱导的肺损伤中的作用，我们知之甚少。由首席研究员生成的初步数据已经确定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时肺部炎症和血管屏障破坏的增加有关。此外，药物抑制C0X2具有保护作用，可减少急性炎症并增强通透性。我们假设C0X2的表达是在高潮气量机械通气的反应中诱导的，并且在伴随VILI的急性炎症和内皮屏障破坏中起重要作用。此外，我们假设选择性C0X2抑制剂的施用可以减轻或预防VILI。本课题拟采用体内和体外模型，探讨C0X2在机械应力诱导肺损伤中的确切作用机制。在SA #1中，我们将描述C0X2在建立良好的小鼠VILI模型中的作用，将C0X2的表达和前列腺素的产生与损伤的生化和组织学指标相关联，并探索00X2在机械应力响应中的调节作用。SA #2将重点关注循环拉伸，这是一种独特的机械应力诱导肺损伤的体外模型。通过内皮阻力、免疫组织化学、蛋白质生物化学、sIRNA、real time/RT-POR和Western blotting的测量，我们将确定00X2在循环应力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局部和全身00X2抑制在VILI中的效果。相关性（见说明书）；急性肺损伤（ALI）是一种毁灭性的综合征，每年在美国导致超过74,000名患者死亡，并且几乎没有治疗选择。急性肺损伤患者需要机械通气，但机械通气本身可引起或加重肺损伤。研究机械应力对通气肺的影响对更好地了解该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)