Mechanical Stress and Myofibroblast Function: Implications for Pulmonary Fibrosis

机械应力和肌成纤维细胞功能：对肺纤维化的影响

• 批准号: 7192876
• 负责人: Nancy Ayers Rice
• 金额: $ 20.48万
• 依托单位: WESTERN KENTUCKY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7192876
• 关键词: Academic Research Enhancement Awards; Apoptosis; Biomedical Research; Bleomycin; Cells; Cessation of life; Collagen; Condition; Cultured Cells; Deposition; Disease; Effectiveness; Epithelial Cells; Extracellular Matrix; Family; Fibrosis; Funding; Gene Expression; Genes; Health Sciences; Histologic; Induction of Apoptosis; Institution; Knockout Mice; Knowledge; Lead; Learning; Lung; Lung diseases; MAP Kinase Gene; Mechanical Stress; Mechanics; Mediating; Modeling; Molecular; Muscle; Myofibroblast; Myosin ATPase; Myosin Heavy Chains; Nitric Oxide; Nitric Oxide Pathway; Pathogenesis; Pathway interactions; Pharmaceutical Preparations; Pharmacologic Substance; Phenotype; Physiological; Production; Proteins; Pulmonary Fibrosis; Purpose; Research; Role; Signal Transduction; Smooth Muscle Actin Staining Method; Students; Therapeutic; Tissues; Toxic effect; Transforming Growth Factors; Transgenic Organisms; United States Food and Drug Administration; Work; Wound Healing; career; design; experience; human NOS3 protein; improved; in vivo; inhibitor/antagonist; interest; interstitial; mouse model; prevent; programs; promoter; repaired; research clinical testing; response

DESCRIPTION (provided by applicant): We are interested in those mechanisms that mediate myofibroblast function under normal and pathological conditions. Myofibroblasts are necessary cells for tissue remodeling and repair. During wound healing myofibroblasts differentiate in response to various cellular signals which results in an increase in their muscle gene expression, extracellular matrix secretion, and contractility. The fact that, under certain circumstances, myofibroblasts persist and continue to secrete extracellular matrix has implicated them in interstitial fibrosis of the lung. In this proposal, we are specifically interested in the role that mechanical stress, i.e. contraction, has in regulating endothelial nitric oxide synthase (eNOS) expression and activity in pulmonary myofibroblasts, and subsequently, how changes in eNOS correlate with myofibroblast apoptosis. Understanding those molecular mechanisms that lead to dissipation of myofibroblasts is essential in rational therapeutic design. Therefore, we propose three specific aims to extend our knowledge regarding the role of contraction in mediating myofibroblast apoptosis via eNOS signaling: 1) we will evaluate how contraction of pulmonary myofibroblasts regulates eNOS expression at the gene, RNA, and protein levels, using primary myofibroblast cell cultures; 2) we will determine how nitric oxide mediates pulmonary myofibroblast apoptosis using various pharmacological donors and selective inhibitors of NOS in primary myofibroblast cell cultures; and 3) we will assess the absence of sarcomeric myosin on bleomycin-induced pulmonary fibrosis in vivo histologically and biochemically using the myosin heavy chain IId null transgenic mouse model. The results from these studies will provide significant advancements in our understanding of the pathogenesis of pulmonary fibrosis and other pulmonary interstitial diseases. Furthermore, over the 3 year funding period, this project will engage numerous undergraduates to independent research, enhancing their learning of scientific principles, giving them an opportunity to make unique contributions to the study of this devastating family of diseases, and stimulating their excitement for careers in biomedical research. Interstitial pulmonary fibrosis is a devastating lung disease that results from excess collagen in lungs as a result of a surplus of, and/or overactive, myofibroblast cells. Since, relatively few drugs are available for the treatment of pulmonary fibrosis, and their effectiveness is minimal at best, a thorough understanding of the mechanisms regulating myofibroblast activity and death is important in designing new, improved therapeutics. The nitric oxide pathway is an ideal place to begin in that this pathway is targeted by numerous pharmaceuticals that have already been evaluated for efficacy and toxicity and are approved for use by the U.S. Food and Drug Administration, potentially eliminating years of clinical testing and saving millions of dollars.

描述（由申请人提供）：我们对在正常和病理条件下介导肌成纤维细胞功能的机制感兴趣。肌成纤维细胞是组织重建和修复所必需的细胞。在伤口愈合期间，肌成纤维细胞响应于各种细胞信号而分化，这导致其肌肉基因表达、细胞外基质分泌和收缩性增加。事实上，在某些情况下，肌成纤维细胞持续存在并继续分泌细胞外基质，这使它们与肺间质纤维化有关。在这个建议中，我们特别感兴趣的作用，机械应力，即收缩，在调节肺肌成纤维细胞内皮型一氧化氮合酶（eNOS）的表达和活性，以及随后，如何在eNOS的变化与肌成纤维细胞凋亡。了解导致肌成纤维细胞消散的分子机制对于合理的治疗设计至关重要。因此，我们提出了三个具体的目标，以扩大我们的知识，收缩介导的作用，通过eNOS信号转导的肌成纤维细胞凋亡：1）我们将评估如何收缩肺肌成纤维细胞调节eNOS表达的基因，RNA和蛋白质水平，使用原代肌成纤维细胞培养物; 2）在原代肌成纤维细胞培养中，我们将使用各种药物供体和选择性NOS抑制剂来确定一氧化氮如何介导肺肌成纤维细胞凋亡;以及3）我们将使用肌球蛋白重链IId缺失转基因小鼠模型，在体内组织学和生物化学上评估肌节肌球蛋白的缺失对博来霉素诱导的肺纤维化的影响。这些研究结果将为我们理解肺纤维化和其他肺间质疾病的发病机制提供重要的进展。此外，在3年的资助期内，该项目将吸引众多本科生进行独立研究，增强他们对科学原理的学习，使他们有机会为研究这一毁灭性疾病家族做出独特贡献，并激发他们对生物医学研究事业的热情。间质性肺纤维化是一种毁灭性的肺部疾病，其起因于由于肌成纤维细胞过剩和/或过度活跃而导致的肺中过量的胶原蛋白。由于可用于治疗肺纤维化的药物相对较少，并且它们的有效性充其量是最小的，因此对调节肌成纤维细胞活性和死亡的机制的透彻理解在设计新的改进的治疗方法中是重要的。一氧化氮途径是一个理想的开始的地方，因为这一途径是许多药物的目标，这些药物已经被评估了疗效和毒性，并被美国食品和药物管理局批准使用，可能消除多年的临床试验，节省数百万美元。