Regulation of Mucous Cell Metaplasia in Asthma

哮喘中粘液细胞化生的调节

• 批准号: 8918138
• 负责人: Yohannes Tesfaigzi
• 金额: $ 20.48万
• 依托单位: LOVELACE BIOMEDICAL & ENVIRONMENTAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8918138
• 关键词: Address; Affect; Aging; Allergens; Amino Acids; Apoptosis; Appearance; Asthma; BIK gene; Binding; Calcium; Cell Death; Cell Death Process; Cells; Cessation of life; Chronic; Clinical; Cohort Studies; DAP kinase; Development; Endoplasmic Reticulum; Epidemiologic Studies; Epithelial Cells; Exposure to; Funding; Generations; Genes; Genotype; Goals; Health; Human; Hyperplasia; Individual; Interferons; Lead; Life; MAPK3 gene; Malignant neoplasm of lung; Mediating; Membrane; Metaplasia; Mitochondria; Molecular; Mucins; Mucous body substance; Mus; Obstruction; Outer Mitochondrial Membrane; Pathway interactions; Patients; Peptides; Phenotype; Process; Promoter Regions; Proteins; Regulation; Regulatory Element; Resistance; Resolution; Respiratory physiology; Risk; STAT1 gene; Scaffolding Protein; Single Nucleotide Polymorphism; Smoker; Testing; Treatment Efficacy; Variant; airway remodeling; base; cohort; cytochrome c; effective therapy; genetic variant; high risk; improved; in vivo; mitochondrial membrane; neoplastic cell; prevent; protein activation

DESCRIPTION (provided by applicant): In patients with asthma mucous cells appear in airways that are normally devoid of these cells. This phenotype is called mucous cell metaplasia (MCM). MCM poses a serious risk because acutely secreted mucus can reduce airflow or can sometimes completely obstruct the airways and lead to death of asthmatics. In addition, epidemiological studies suggest that patients with chronic MCM are at a higher risk of developing lung cancer. During the previous funding period, we discovered that that for the resolution of allergen-induced MCM during prolonged exposure to an allergen, IFN? through STAT1 activation requires Bik, a protein that is anchored in the endoplasmic reticulum (ER). Bak is so crucial for IFN?- or Bik-induced cell death that airway epithelial cells from bak-/- or even bak+/- primary cells are resistant. We found that Bik interacts with the 160 kDa death-associated protein kinase 1 (DAPk), to tether ER and mitochondria, orchestrate the assembly of ERK1/2 and Bak to activate Bak, and facilitate the release of ER calcium. We generated a Bik-derived peptide that similar to IFN? and Bik activates Bak. We also identified a single nucleotide polymorphism (A G) in the intronic region of the BIK gene that reduces Bik expression levels in differentiated normal human bronchial epithelial cells (NHBEs) and is associated with a significant decline in lung function in two cohort studies. Therefore, this renewal application is focused on delineating the molecular interaction of Bik and DAPk to help optimize the generation of improved Bik-derived peptides that restore Bik function in individuals with the BIK variant that causes reduced Bik levels and resolve MCM. We propose the following hypotheses: IFN?- induced cell death is mediated by Bik binding to DAPk to facilitate the activation of Bak, release ER Ca2+ to mitochondria, and initiation of apoptosis. Furthermore, restoring Bik levels in subjects with a BIK gene variant that causes reduced Bik levels can be an effective way to reduce MCM. We will test these hypotheses by: (1) Elucidating the molecular interaction of Bik and DAPk that facilitates assembly of ERK1/2 and Bak to cause activation of Bak, and by testing whether DAPk tethers ER and mitochondria to coordinate the transfer of ER calcium to mitochondria and disrupt the integrity of the mitochondrial outer membrane. (2) Determining whether a peptide derived from Bik restores resolution of MCM in NHBEs with GG and AG compared to AA genotype and whether a Bik-derived peptide reduces MCM and reverses decline in lung function in bik+/+, bik+/-, and bik-/- mice exposed to allergen. Understanding the molecular mechanisms of the resolution process of MCM will allow us to develop more effective peptides for patients with bronchitic asthma and the BIKGG genotype. This strategy may help maximize the effect of reducing excessive mucus in susceptible individuals and help target pre-neoplastic cells that may survive among hyperplastic cells to prevent the development of lung cancer in high-risk individuals.

描述（由申请人提供）：在哮喘粘液细胞患者中，出现在通常没有这些细胞的气道中。该表型称为粘液细胞化生（MCM）。 MCM构成了严重的风险，因为急性分泌的粘液可以减少气流，或者有时会完全阻碍气道并导致哮喘患者死亡。此外，流行病学研究表明，患有慢性MCM的患者患肺癌的风险更高。在上一个资金期间，我们发现在长时间暴露于过敏原IFN的情况下解决过敏原诱导的MCM？通过STAT1激活需要Bik，Bik是一种锚定在内质网（ER）中的蛋白质。 BAK对于IFN？ - 或BIK诱导的细胞死亡至关重要，以至于来自BAK - / - 甚至BAK +/-原代细胞的气道上皮细胞具有抗性。我们发现，Bik与160 kDa死亡相关的蛋白激酶1（DAPK）相互作用，与系绳ER和线粒体相互作用，协调ERK1/2的组装和BAK以激活Bak，并促进ER钙的释放。我们生成了类似于IFN的BIK衍生的肽？ Bik激活了Bak。我们还鉴定了BIK基因内含子区域中的单个核苷酸多态性（A G），可在分化的正常人支气管上皮细胞（NHBE）中降低BIK表达水平（NHBE），并与两项队列研究中的肺功能显着下降有关。因此，这种更新应用的重点是描述BIK和DAPK的分子相互作用，以帮助优化改进的BIK衍生肽的生成，这些肽在具有降低BIK水平并解决MCM的BIK变体的个体中恢复BIK的功能。我们提出以下假设：IFN？ - 诱导的细胞死亡是由BIK与DAPK结合介导的，以促进BAK的激活，将ER Ca2+释放至线粒体和凋亡的启动。此外，用BIK基因变异的受试者恢复BIK水平，从而导致BIK水平降低，这可能是减少MCM的有效方法。 We will test these hypotheses by: (1) Elucidating the molecular interaction of Bik and DAPk that facilitates assembly of ERK1/2 and Bak to cause activation of Bak, and by testing whether DAPk tethers ER and mitochondria to coordinate the transfer of ER calcium to mitochondria and disrupt the integrity of the mitochondrial outer membrane. (2) Determining whether a peptide derived from Bik restores resolution of MCM in NHBEs with GG and AG compared to AA genotype and whether a Bik-derived peptide reduces MCM and reverses decline in lung function in bik+/+, bik+/-, and bik-/- mice exposed to allergen.了解MCM分辨率过程的分子机制将使我们能够为支气管哮喘和Bikgg基因型的患者开发更有效的肽。该策略可能有助于最大程度地减少易感个体中过度粘液的影响，并有助于靶向可能在增生细胞中生存的肿瘤前细胞，以防止高风险个体中肺癌的发展。