Alveolar Tissuegenesis in Murine Acute Lung Injury

小鼠急性肺损伤中的肺泡组织发生

基本信息

批准号：
7734556
负责人：
WILLIAM J. MARTIN
金额：
$ 96.01万
依托单位：
NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/7734556
关键词：
Acute Acute Lung Injury Adult Adult Respiratory Distress Syndrome Affect Alveolar Alveolar Process Alveolar capillary destruction Animal Model Antineoplastic Agents Apoproteins Apoptosis Bleomycin Blood capillaries Capillary Endothelial Cell Cause of Death Cell Therapy Cells Chemotherapy-Oncologic Procedure Child Childhood Injury Cicatrix Computer Assisted Critical Illness Development Diffuse Endothelial Cells Endothelium Engineering Engraftment Environment Epithelial Epithelial Cells Equipment Event Fibrosis Gases Goals Herbicides Human Resources Hyperoxia Inflammatory Injury Intensive Care Units Knowledge Laboratories Localized Lung Marrow Mediating Membrane Methods Mitochondria Mitochondrial DNA Modeling Molecular Morbidity - disease rate Mus Oxidative Stress Paraquat Pathologic Patients Personal Satisfaction Phospholipids Play Premature Infant Process Production Proteins Pulmonary Fibrosis Pulmonary Surfactants Recovery Respiratory physiology Role Secondary to Site Stem cells Structure Structure of parenchyma of lung Surface Therapeutic Thinking Time Toxic effect Toxin Type I Epithelial Receptor Cell Type II Epithelial Receptor Cell Wound Healing alveolar epithelium body system capillary cell injury cell type cytotoxic design experience improved indium-bleomycin injured injury and repair insight lung injury macrophage mortality mouse model next generation novel novel strategies novel therapeutics prevent progenitor repaired restoration surfactant

项目摘要

The alveolar tissuegenesis project is underway with completion of the transfer of my laboratory equipment and personnel in June 2006. Our goal is to establish the model of bleomycin induced acute lung injury in C57/BL6 mice and to demonstrate that airway delivery of freshly isolated type II alveolar epithelial cells from normal mice will reduce the lung injury in the bleomycin treated mice. The proposal is as follows. Acute lung injury is a major cause of morbidity and mortality in both children and adults. The pathologic hallmark of acute lung injury is diffuse alveolar damage. The damage is a direct result of injury to the alveolar epithelial cells and capillary endothelial cells maintaining the alveolar capillary barrier. The alveolar epithelium appears to be especially important as a site of injury as it is primary responsible for maintaining the integrity of the alveolar capillary membrane as well as synthesizing and processing of alveolar surfactant phospholipids and surfactant associated proteins. Various agents have been used to model acute lung injury including such as bleomycin that is used in cancer chemotherapy, hyperoxia which is commonly required to maintain normoxemia in critically ill patients, and pulmonary specific toxins such as the herbicide paraquat. Some agents such as hyperoxia predominantly damage the pulmonary capillary endothelial cell; whereas, other agents such as paraquat may predominantly damage the type I and type II alveolar epithelial cells. In practice, most agents that result in acute lung injury damage both the alveolar epithelium and the pulmonary capillary endothelium. Whereas injury occurs to both capillary endothelial cells and type I and type II alveolar epithelial cells during acute lung injury, it is the loss of the alveolar epithelial cells that appears to be critical for destruction of the alveolar capillary units and subsequent development of fibrosis (scarring of lung tissue). One approach to potentially reverse the catastrophic events associated with acute lung injury is to restore the alveolar capillary unit and its barrier function. Molecular mechanisms associated with pulmonary fibrosis are still obscure. Apoptosis has been thought to be a non-inflammatory means of removing injurious cells thus facilitating lung injury. Mitochondria play an important role in mediating apoptosis thus functional understanding of mitochondria during oxidative stress secondary to bleomycin will help us to design a better model for lung injury and repair. In addition, restoration of alveolar type II epithelial cell could help restore the normal synthesis and processing of pulmonary surfactant and surfactant apoproteins, which would be especially important for premature infants with insufficient pulmonary surfactant production. The type II cell is in the lung and also is considered the progenitor of the type I cell which is important for gas exchange. Recent studies indicate that during acute lung injury from bleomycin, marrow-derived progenitor cells administered intravenously can migrate to the lung and change into alveolar epithelial cells. It remains unclear whether this process of engraftment can actually reduce acute lung injury and even mortality. This is a very important question to answer. Since our laboratory has significant experience with alveolar epithelial cells, acute lung cell injury and bleomycin toxicity animal models, we are well suited to investigate the therapeutic potential of tissuegenesis initiated by the delivery of type II cells. While the mechanisms of bleomycin-induced lung cell toxicity have been well studied, current therapy to reduce the lung toxicity is inadequate and novel therapeutic approaches for affected patients need to be developed. Our laboratory has recently demonstrated the feasibility of airway delivery of genetically engineered macrophages to the alveolar structures to modify the alveolar environment (PNAS 98:14589-94, 2001). We propose that airway delivery of type II cells or other potential progenitor cells during bleomycin lung injury will result in successful engraftment of these cells onto the injured alveolar surface. This is the first study to our knowledge where airway delivery of cells has been used therapeutically to alter the alveolar environment. If successful, these studies would represent a new approach to alveolar tissue repair during acute lung injury and would be potentially applicable to treat acute lung injury in children and adults. Hypothesis: Airway delivery of alveolar epithelial progenitor cells to the alveolar structures during bleomycin lung injury will result in engraftment and replacement of the injured alveolar epithelium and will hasten recovery of lung function and increase survival. Primary Specific Aims: 1.To determine mechanisms of bleomycin mediated injury to alveolar epithelial cells. 2.To demonstrate that delivery of alveolar epithelial progenitor cells (e.g. type II alveolar epithelial cells) in a mouse model will localize to the alveolar structures and engraft to the injured alveolar surface during bleomycin-induced acute lung injury. 3.To determine if successful engraftment of alveolar epithelial progenitor cells to the alveolar epithelium will hasten recovery from bleomycin-induced acute lung injury and increase survival. In the past year since we arrived at NIEHS, we have established that our lab can recreate the injury model by bleomycin and that we can successfully isolate the type II cells in sufficient purity and viability to conduct the proposed studies. Additionally we have enhanced our ability to quantify bleomycin-induced lung injury using computer-assisted morphometric analysis with Metamorph which will permit for the first time a quantitative approach to bleomycin injury at baseline as well as to assess the impact of donor type II cells as repair cells. Furthermore, we have also demonstrated how bleomycin damages alveolar epithelial cells by oxidative damage to mitochondrial DNA which is another first in bleomycin injury. Both of these studies will enhance our approach to improving repair of bleomycin injury.

The alveolar tissuegenesis project is underway with completion of the transfer of my laboratory equipment and personnel in June 2006. Our goal is to establish the model of bleomycin induced acute lung injury in C57/BL6 mice and to demonstrate that airway delivery of freshly isolated type II alveolar epithelial cells from normal mice will reduce the lung injury in the bleomycin treated mice.该提议如下。急性肺损伤是儿童和成人发病率和死亡率的主要原因。急性肺损伤的病理标志是弥漫性肺泡损伤。损伤是损伤肺泡上皮细胞和维持牙槽毛细管屏障的毛细管内皮细胞的直接结果。肺泡上皮似乎是损伤部位尤其重要，因为它主要负责维持牙槽毛细血管膜的完整性以及肺泡表面活性剂磷脂和表面活性剂相关蛋白的合成和加工。各种药物已被用于对急性肺损伤进行建模，包括用于癌症化疗中的博霉素，高氧症，通常需要维持重症患者的常氧血症以及肺特异性毒素，例如除草剂paraquat。一些药物（例如高氧）主要损害肺毛细管内皮细胞。而其他药物（例如Paraquat）可能主要损害I型和II型肺泡上皮细胞。实际上，大多数导致急性肺损伤的药物都会损害肺泡上皮和肺毛细管内皮。尽管毛细血管内皮细胞和I型和II型肺泡上皮细胞均发生损伤，但肺泡上皮细胞的丧失似乎对于破坏了肺泡毛细管单元和随后的纤维化发育至关重要（肺组织疤痕）。一种可能扭转与急性肺损伤相关的灾难性事件的方法是恢复肺泡毛细管单元及其屏障功能。与肺纤维化相关的分子机制仍然晦涩。凋亡被认为是消除损害细胞的一种非炎症手段，从而促进了肺损伤。线粒体在介导细胞凋亡中起重要作用，因此在博来霉素继发的氧化应激期间对线粒体的功能理解将有助于我们为肺损伤和修复设计更好的模型。此外，恢复肺泡II型上皮细胞可以有助于恢复肺表面活性剂和表面活性剂的正常合成和加工，这对于肺表面活性剂不足的过早婴儿尤为重要。 II型细胞在肺中，也被认为是I型细胞的祖细胞，这对于气体交换很重要。最近的研究表明，在博霉素急性肺损伤中，静脉内给药的骨髓衍生的祖细胞可以迁移到肺部并变成肺泡上皮细胞。目前尚不清楚这种植入过程是否可以真正减少急性肺损伤甚至死亡率。这是一个非常重要的问题。由于我们的实验室在肺泡上皮细胞，急性肺细胞损伤和博来霉素毒性动物模型方面具有丰富的经验，因此我们非常适合研究通过递送II型细胞引发的组织性的治疗潜力。虽然已经对博来霉素诱导的肺部毒性的机制进行了充分的研究，但需要开发患者的当前疗法以降低肺毒性，而新颖的治疗方法需要得到开发。我们的实验室最近证明了基因工程巨噬细胞向肺泡结构传递的可行性，以修改肺泡环境（PNAS 98：14589-94，2001）。我们建议在博来霉素肺损伤过程中气道输送II型细胞或其他潜在的祖细胞，将成功植入这些细胞上受伤的肺泡表面。这是我们所知的第一项研究，在治疗上使用了气道传递来改变肺泡环境。如果成功，这些研究将代表急性肺损伤期间肺泡组织修复的新方法，并且可能适用于治疗儿童和成人的急性肺损伤。假设：在博来霉素肺损伤期间，气道将肺泡上皮祖细胞递送至肺泡结构，将导致植入和替代受伤的肺泡上皮，并加快肺功能的恢复并增加存活率。主要特定目的： 1.确定博来霉素介导的肺泡上皮细胞损伤的机制。 2.证明小鼠模型中肺泡上皮祖细胞（例如II型肺泡上皮细胞）的递送将定位于肺泡结构，并在博霉素诱导的急性肺损伤期间植入受伤的肺泡表面。 3.确定成功植入肺泡上皮祖细胞到肺泡上皮是否会加速从博来霉素诱导的急性肺损伤并增加存活率。自从我们到达NIEHS以来的过去一年中，我们已经确定我们的实验室可以通过博来霉素重现损伤模型，并且我们可以成功地以足够的纯度和生存能力将II型细胞分离以进行拟议的研究。此外，我们通过使用计算机辅助的形态计算分析来量化博来霉素诱导的肺损伤的能力，该分析将首次允许在基线时首次定量的博霉素损伤方法，并评估供体II型II型细胞作为修复细胞的影响。此外，我们还证明了博来霉素如何通过对线粒体DNA的氧化损伤来损害肺泡上皮细胞，这是博来霉素损伤的另一个。这两项研究都将增强我们改善博来霉素损伤修复的方法。