LUNG ELASTIN IN BRONCHOPULMONARY DYSPLASIA

支气管肺发育不良中的肺弹性蛋白

• 批准号: 7349770
• 负责人: Richard A Pierce
• 金额: $ 3.55万
• 依托单位: TEXAS BIOMEDICAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7349770
• 关键词: LUNG; ELASTIN; BRONCHOPULMONARY; DYSPLASIA

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The focus of this proposal is to characterize mechanisms controlling elastin synthesis and turnover during the development of bronchopulmonary dysplasia (BPD) resulting from ventilation of the premature lung. Elastin confers the requisite property of elastic recoil to such lung structures as alveoli and alveolar ducts, bronchioles, and blood vessels, and thus is essential for lung function. We have previously demonstrated abnormal elastic fiber deposition in an experimental model of BPD, and others have demonstrated increased elastolytic activity in the BPD lung. Still, the root causes of elastic fiber abnormalities in BPD are not known. We hypothesize that mesenchymal cells of the premature lung respond to the strain of mechanical ventilation by increasing the expression and deposition of elastic extracellular matrix components out of proportion to what is required for alveolarization. Exposure to hyperoxia may result in the production and release of elastases such as neutrophil elastase or matrix metalloproteinases that damage elastic fibers, as well as cytokines or growth factors that alter extracellular matrix gene expression by lung fibroblasts. These events result in the excess deposition of disordered elastic fibers at sites of failed development of new alveolar walls. The accumulation of disorganized elastic fibers at these sites may limit the ability to recover from injury. To determine the causes of abnormal elastic fiber deposition during the development of BPD, we propose to study the expression of elastin, fibrillins1 and 2, and lysyl oxidase, all required for normal elastic fiber synthesis, and to characterize the elastases present in the injured lung. Our experimental approaches will include quantitative analysis of elastic fiber-related and elastase mRNA expression by RNAse protection assays, as well as localization of expression by in situ hybridization and immunohistochemical analyses. The molecular mechanisms regulating tropoelastin expression during normal baboon lung development and the development of BPD will be determined by assessing changes in tropoelastin gene transcription, steady-state mRNA levels, and protein synthesis, expression and activity of elastases in the BPD lung will be assessed by a combination of substrate zymography, immunohistochemistry, and in situ hybridization. Determining the effects of interventive treatments on the expression of elastic fiber-related genes and the elaboration of elastases will test the hypothesis that treatment which prevent BPD will also restore normal patterns of elastic fiber-related gene expression and elastic fiber deposition.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子弹和调查员（PI）可能已经从其他NIH来源获得了主要资金，因此可以在其他清晰的条目中代表。列出的机构适用于该中心，这不一定是调查员的机构。该提案的重点是表征控制弹性蛋白合成和周转期间支气管肺发育不良（BPD）（BPD）的机制。弹性蛋白将弹性后坐力的必要特性赋予了肺泡和肺泡管，支气管和血管等肺结构，因此对于肺功能至关重要。我们以前已经在BPD实验模型中证明了异常的弹性纤维沉积，而其他弹性纤维沉积在BPD肺中显示出弹性溶剂的增加。尽管如此，尚不清楚弹性纤维异常的根本原因。我们假设过早肺的间充质细胞通过增加弹性的细胞外基质成分的表达和沉积与肺泡化所需的内容成正比，从而对机械通气的应变做出反应。暴露于高氧可能会导致弹性酶的产生和释放，例如中性粒细胞弹性酶或损害弹性纤维的基质金属蛋白酶，以及通过肺成纤维细胞改变细胞外基因表达的细胞因子或生长因子。这些事件导致无序弹性纤维在新肺泡壁发育失败的部位的过量沉积。这些位点上混乱的弹性纤维的积累可能会限制从损伤中恢复的能力。为了确定BPD发育过程中异常弹性纤维沉积的原因，我们建议研究弹性纤维合成的弹性蛋白，Fibrillins1和2和赖氨酸氧化酶的表达，这都是正常弹性纤维合成所必需的，并表征了受伤的肺中存在的弹性酶。我们的实验方法将包括通过RNase保护测定法对弹性纤维相关和弹性酶mRNA表达的定量分析，以及通过原位杂交和免疫组织化学分析对表达进行定位。 The molecular mechanisms regulating tropoelastin expression during normal baboon lung development and the development of BPD will be determined by assessing changes in tropoelastin gene transcription, steady-state mRNA levels, and protein synthesis, expression and activity of elastases in the BPD lung will be assessed by a combination of substrate zymography, immunohistochemistry, and in situ hybridization.确定干预处理对弹性纤维相关基因表达的影响以及弹性酶的阐述将检验以下假设：预防BPD的治疗也将恢复弹性纤维相关基因表达和弹性纤维沉积的正常模式。