Regulation of Fas-Mediated Lung Cell Apoptosis

Fas 介导的肺细胞凋亡的调节

• 批准号: 7211462
• 负责人: Yon Rojanasakul
• 金额: $ 35.56万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7211462
• 关键词: Acute Lung Injury; Alveolar; Antibodies; Apoptosis; Apoptosis Inhibitor; Apoptosis Regulator; Apoptotic; Autoimmunity; Biochemical; Biological Assay; Bleomycin; CASP8 and FADD-like apoptosis regulating protein; Caspase; Cell Death; Cell Differentiation process; Cells; Cessation of life; Class; Complex; Cysteine Protease; Defect; Development; Diffuse; Disease; Down-Regulation; Ectopic Expression; Effectiveness; Epithelial; Equilibrium; Event; Exposure to; Failure; Family; Fas Signaling Pathway; Fibrosis; Gene Deletion; Hamman-Rich syndrome; Homeostasis; Human; Induction of Apoptosis; Inflammatory; Ligands; Link; Lung; Lung diseases; Maintenance; Malignant Neoplasms; Mediating; Mitochondria; Molecular; Molecular Biology; Mus; Nerve Degeneration; Organism; Oxidative Stress; Pathogenesis; Pathologic; Pathology; Pathway interactions; Physiological; Play; Pneumonia; Post-Translational Protein Processing; Predisposition; Prevention; Prevention strategy; Process; Proteins; Reactive Oxygen Species; Regulation; Reporting; Research Personnel; Risk Assessment; Role; Signal Pathway; Signal Transduction; Silicon Dioxide; Site; Site-Directed Mutagenesis; Source; Stroke; Surface; System; TP53 gene; Techniques; Testing; Therapeutic; Therapeutic Intervention; Tissues; Tumor Necrosis Factor Ligand Superfamily Member 6; Ubiquitin; Ubiquitination; Up-Regulation; base; caspase-8; cell growth regulation; cell suicide; cell type; human disease; inhibitor-of-apoptosis protein; insight; member; multicatalytic endopeptidase complex; programs; promoter; protein degradation; receptor; response

DESCRIPTION (provided by applicant): Defects in apoptosis or programmed cell death regulation contribute to many human diseases, including those of the lung. Recent evidence indicates that Fas(CD95)-mediated apoptosis plays an important role in the pathogenesis of several pulmonary diseases. However our understanding of the mechanisms involved in the process is limited. Failure to understand such mechanisms directly limits the effectiveness of prevention and therapeutic efforts. The overall objective of this study is to provide a scientific basis for a mechanistic understanding of the molecular events involved in Fas-mediated apoptosis and its regulation in specific lung cells. Our preliminary findings indicate that while Fas can trigger apoptosis of lung cells, the expression level of Fas and its activation by Fas ligand (FasL) do not correlate with the susceptibility to Fas-mediated cell death, indicating that regulators of the apoptosis-signaling pathway must exist. In this project we will seek to identify key regulators controlling Fas-mediated cell death of lung cells and elucidate their mechanisms. The project will specifically test the hypotheses that susceptibility to Fas-mediated apoptosis and associated lung pathologies may be determined by the expression level of cellular FLICE-inhibitory protein (c-FLIP) and that alterations of this protein by certain pneumotoxic agents can sensitize cells to Fas- mediated cell death via an activation of caspase-8 and downstream caspase cascade. We will determine the functional role of c-FLIP and identify the death signaling pathways in primary lung cells using various molecular biology and biochemical techniques. We will also test the hypothesis that downregulation of c- FLIP through post-translational modifications is a critical regulatory event controlling Fas-mediated cell death and survival via caspase-8 and NF-(B signaling pathway. Because our preliminary findings indicate critical roles of reactive oxygen species (ROS) and ubiquitin-proteasome dependent pathway in c-FLIP degradation and Fas signaling, we will elucidate the underlying mechanisms and identify specific ROS involved and their cellular sources. Furthermore, we will determine specific ubiquitination sites on c-FLIP that target this molecule for degradation using site-directed mutagenesis and gene deletion assays. It is expect that the proposed studies will provide valuable new information on the mechanisms of cell death regulation and associated lung disorders which will be important in risk assessment and therapeutic intervention.

描述（由申请人提供）：细胞凋亡或程序性细胞死亡调节的缺陷导致许多人类疾病，包括肺部疾病。最近的证据表明Fas(CD95)介导的细胞凋亡在多种肺部疾病的发病机制中发挥着重要作用。然而，我们对该过程所涉及的机制的理解是有限的。不了解这些机制直接限制了预防和治疗工作的有效性。本研究的总体目标是为理解 Fas 介导的细胞凋亡及其在特定肺细胞中的调节所涉及的分子事件的机制提供科学基础。我们的初步研究结果表明，虽然Fas可以引发肺细胞凋亡，但Fas的表达水平及其由Fas配体（FasL）的激活与Fas介导的细胞死亡的易感性并不相关，这表明凋亡信号通路的调节因子必须存在。在这个项目中，我们将寻求确定控制 Fas 介导的肺细胞细胞死亡的关键调节因子，并阐明其机制。该项目将具体测试以下假设：对 Fas 介导的细胞凋亡和相关肺部病理的易感性可能由细胞 FLICE 抑制蛋白 (c-FLIP) 的表达水平决定，并且某些肺毒性药物对该蛋白的改变可以通过激活 caspase-8 和下游 caspase 级联使细胞对 Fas 介导的细胞死亡敏感。我们将使用各种分子生物学和生化技术确定 c-FLIP 的功能作用并识别原代肺细胞中的死亡信号通路。我们还将测试以下假设：通过翻译后修饰下调 c-FLIP 是通过 caspase-8 和 NF-(B 信号通路控制 Fas 介导的细胞死亡和存活的关键调控事件。因为我们的初步研究结果表明活性氧 (ROS) 和泛素蛋白酶体依赖性通路在 c-FLIP 降解和 Fas 信号传导中发挥关键作用，所以我们将 阐明潜在机制并确定所涉及的特定 ROS 及其细胞来源。此外，我们将使用定点诱变和基因删除测定来确定 c-FLIP 上针对该分子进行降解的特定泛素化位点。预计拟议的研究将提供有关细胞死亡调节机制和相关肺部疾病的有价值的新信息，这对于风险评估和治疗干预非常重要。