Resolution of Epithelial Cell Hyperplasia in Asthma

项目总结/摘要 在之前的资助期间，我们阐明了Bik/Nbk诱导细胞凋亡的分子机制， 增生性气道上皮细胞（AEC），并鉴定了激活巴克和降低 粘液细胞增生（MCH）。当我们评估Bik缺乏对MCH的影响时，我们 注意到，在雌性小鼠中，而不是雄性小鼠中，与bik+/+小鼠相比，bik-/-小鼠在 对LPS和香烟烟雾暴露的反应。此外，我们注意到滴注Bik衍生肽或 Bik在AEC中的转基因表达以可诱导的方式抑制变应原诱导的炎症。甚至 更令人惊讶的是，与基线时的bik+/+小鼠相比，bik-/-小鼠肺组织中的IL-6水平增加， 没有炎症刺激，并且BIK-/-小鼠在80周龄时发展为肺气肿。Bik的作用 我们的观察证实了调节炎症的原代小鼠气道上皮细胞（MAECs）， 与bik+/+相比，雌性bik-/-显示核因子κ B（NF-κB）水平增加。在人类中，我们发现 BIK启动子区域内的单核苷酸多态性（SNP）与肺功能下降相关， 在年龄大于60岁的受试者的四个独立队列中发挥作用。A/CN.9/2008/03/2008/09 BIK基因表达和具有降低的Bik水平的雌性显示增加的循环IL-6水平。因为比克 我们认为这是Bik的实际功能，而不是它的细胞 死亡诱导活性;并且如果不加抑制，则可导致老化期间的肺破坏。因此，此次更新 本申请集中于阐明Bik在通过降低核p65水平阻断炎症中的中心作用。 目的1将确定Bik和Bcl-2在ER的定位对于减少基线炎症的重要性 在没有炎症刺激的情况下Bik和Bcl-2蛋白内功能位点的突变将显示这些位点 Bik、Bcl-2和p65之间的相互作用。此外，雌性细胞中Bcl-2表达增加的可能作用 引起炎症中的性别依赖性差异的原因将被探索。目标2将测试Bik的因果作用 通过使用Bik的腺病毒表达来恢复Bik水平或用Bik治疗， 用于降低分化的bik-/-MAEC和原代人气道上皮细胞中分泌的IL-6水平的Bik衍生肽 G等位基因纯合子的细胞。此外，Bik在老年肺气肿发展中的因果作用 将使用Bik-/-小鼠肺中Bik的转基因诱导表达来评价雌性小鼠，以阻断 基线炎症。这些研究将为COPD的精确药物治疗奠定基础， 哮喘性支气管炎

Project Summary/Abstract During the previous funding period we elucidated the molecular mechanisms of Bik/Nbk-induced apoptosis in hyperplastic airway epithelial cells (AECs) and identified Bik-derived peptides that activate Bak and reduce mucous cell hyperplasia (MCH) in mice. While we were evaluating the effects of Bik deficiency on MCH, we noticed that among females, but not males, bik-/- compared with bik+/+ mice show enhanced inflammation in response to LPS and cigarette smoke exposure. Further, we noticed that instillation of Bik-derived peptides or transgenic expression of Bik in AECs in an inducible fashion suppressed allergen-induced inflammation. Even more striking was that IL-6 levels were increased in lung tissues of bik-/- compared with bik+/+ mice at baseline in the absence of inflammatory stimuli, and that bik-/- mice develop emphysema at 80 weeks of age. The role of Bik in regulating inflammation was confirmed by our observation that primary murine airway epithelial cells (MAECs) from female bik-/- compared with bik+/+ show increased levels of nuclear factor kappaB (NF-κB). In humans, we identified a single nucleotide polymorphism (SNP) within the BIK promoter region that is associated with decline in lung function in four independent cohorts for subjects older than 60 years of age. The AG change causes reduced BIK gene expression and females with reduced Bik levels show increased circulating IL-6 levels. Because Bik blocks baseline inflammation in naïve bik-/- mice we propose that this is the actual function of Bik rather than it's cell death inducing activity; and if left unchecked can lead to lung destruction during aging. Therefore, this renewal application is focused on elucidating the central role of Bik in blocking inflammation by reducing nuclear p65 levels. Aim 1 will determine the importance of localization of Bik and Bcl-2 at the ER for reducing inflammation at baseline in the absence of inflammatory stimuli. Mutations of functional sites within Bik and Bcl-2 proteins will show the sites of interaction between Bik, Bcl-2 and p65. Further, the possible role of increased Bcl-2 expression in female cells causing the sex-dependent differences in inflammation will be explored. Aim 2 will test the causal role of Bik deficiency on increased inflammation by restoring Bik levels using adenoviral expression of Bik or treating with the Bik-derived peptide to reduce secreted IL-6 levels in differentiated bik-/- MAECs and primary human airway epithelial cells homozygous for the G allele. Further, the causal role of Bik in the development of emphysema in aging female mice will be evaluated using transgenic inducible expression of Bik in the lungs of bik-/- mice to block baseline inflammation. These studies will lay the foundation for a precision medicine-based treatment of COPD and asthmatic bronchitis.