Mechanisms of MCP-1 in lung contusion with and without gastric aspiration

描述（由申请人提供）：肺挫伤是机动车事故和爆炸创伤受害者的常见损伤。它也是ALI、ARDS和呼吸机相关性肺炎发生的独立危险因素。根据我们在动物中的初步研究，它在临床上经常与创伤时的胃吸入相关，这可能进一步增加肺损伤的严重程度和ALI/ARDS的风险。目前的建议研究小鼠模型的孤立肺挫伤和肺挫伤与胃吸入。重点是从机制上理解MCP-1和MCP-5在这些损伤的发病机制中的保护作用，包括这种趋化因子在促进肺泡巨噬细胞的募集和激活以及随后对凋亡中性粒细胞的吞噬作用中的特异性作用。该补助金有三个具体目标。目的1研究在缺乏MCP-1、MCP-5或受体蛋白CCR 2的敲除小鼠以及给予针对这些分子的抗体的野生型小鼠中肺挫伤的肺损伤和先天性肺部炎症。这些体内研究通过额外的实验进行补充，其中离体检查分离的肺泡巨噬细胞的表型参数、吞噬潜力和细胞特异性炎症介质谱。此外，提出了通过使用骨髓来源的嵌合体来调查主要负责肺挫伤中MCP-1产生的细胞的起源。此外，TLR 9与细胞内衔接蛋白MyD 88作为损伤识别和随后的激活和MCP-1从肺泡巨噬细胞的阐述的中间体的重要性进行了研究。目的2涉及与目的1类似的研究，以确定MCP-1和MCP-5在肺挫伤与胃吸入联合损伤模型中的详细活性和作用机制。具有肺泡巨噬细胞活性的趋化因子的活性和TLR 9在MCP-1或MCP-5产生中的作用的精确机制与目的1相似。目的3检测通过直接滴注和通过电穿孔促进的含有MCP-1的DNA质粒的基因递送将外源性MCP-1递送到肺挫伤和肺挫伤伴胃吸入后的MCP-1（-/-）和野生型小鼠的肺的效果。这些后面的研究扩展了目标1和2，以进一步记录MCP-1在有和没有胃吸入的肺挫伤中的功能意义，同时研究基于该趋化因子或相关药物的肺部递送的潜在未来疗法的功效。

DESCRIPTION (provided by applicant): Lung contusion is a common injury sustained by victims of motor vehicular accidents and blast trauma. It is also an independent risk factor for the development of ALI, ARDS and ventilator associated pneumonia. It is frequently associated clinically with gastric aspiration at the time of trauma that can further increase the severity of lung injury and the risk of ALI/ARDS based on our preliminary studies in animals. The current proposal studies murine models of both isolated lung contusion and lung contusion with gastric aspiration. Emphasis is on mechanistic understanding of the protective roles of MCP-1and MCP-5 in the pathogenesis of these injuries alone and in combination, including specific effects of this chemokine in facilitating the recruitment and activation of alveolar macrophages and the subsequent phagocytosis of apoptotic neutrophils. The grant has three Specific Aims. Aim 1 investigates lung injury and innate pulmonary inflammation in lung contusion in knockout mice lacking MCP-1, MCP-5 or the receptor protein CCR2, as well as in wild type mice given antibodies against these molecules. These in vivo studies are complemented by added experiments where isolated alveolar macrophages are examined ex vivo for phenotypic parameters, phagocytic potential, and cell-specific inflammatory mediator profile. Additionally, an investigation of origin of cells primarily responsible for the production of MCP-1 in lung contusion through the use of bone marrow-derived chimeras is proposed. In addition, the importance of TLR9 with the intracellular adaptor protein MyD 88 as an intermediate in the recognition of injury and the subsequent activation and elaboration of MCP-1 from alveolar macrophages is investigated. Aim 2 involves analogous studies to those in Aim 1 to define the detailed activities and mechanisms of action of MCP-1 and MCP-5 in the combined injury model of lung contusion with gastric aspiration. The precise mechanisms of activity of chemokines with alveolar macrophage activity and role of TLR9 in the production of MCP-1 or MCP-5 are similar to aim 1. Aim 3 examines the effects of delivering exogenous MCP-1 to the lungs via direct instillation and by electroporation-facilitated gene delivery of DNA plasmids containing MCP-1 to MCP-1 (-/-) and wild type mice following lung contusion and lung contusion with gastric aspiration. These latter studies extend Aim 1 and 2 to further document the functional significance of MCP-1 in lung contusion with and without gastric aspiration, while at the same time investigating the efficacy of potential future therapies based on the pulmonary delivery of this chemokine or related agents.