MECHANISMS OF HUMAN AIRWAY MUCOUS CELL HYPERPLASIA

描述(申请人摘要)：粘液细胞增生症常见于 患有炎症性呼吸道疾病的患者，包括哮喘、COPD、 支气管扩张症和囊性纤维化。尽管增加了 黏液对呼吸道阻塞和细菌感染的调节机制 粘液细胞增生症尚未阐明。在此，我们建议 白介素13(IL-13)是控制卵巢癌发生发展的关键调节分子。 粘液细胞增生症。IL-13是由炎症细胞在脑血管病变部位释放的 受伤或发炎。它结合了呼吸道上皮细胞的表面受体， 并迅速诱导分化为粘液表型，随后 产生粘液的细胞的增殖。这种扩散受到了控制 通过IL-13启动的细胞内信号级联 磷脂酰肌醇3‘-激酶(P13-3’-Kinase)起着核心作用。这个 需要解决的特定假设是IL-13诱导粘液细胞 通过两条途径进行增殖，这两条途径汇聚在一起激活了一种酶， 磷脂酰肌醇3‘端激酶(P13’K)。这些路径包括 转化生长因子-α的自分泌/旁分泌相互作用 与表皮生长因子受体(EGF-R)和IL-13 受体介导的胰岛素受体底物2(IRS-2)的激活。 增强的F13‘激酶活性通过以下途径刺激增殖 激活下游调节细胞周期的酶(如p70-S6K、CDK2)， 导致产生粘液的细胞增加。正常人支气管 上皮性(NHBE)细胞将被用作体外模型来解决上述问题 假设。特定的培养条件将维持这些细胞，以便 在再生的早期阶段重建受损的上皮，或建立细胞模型 在利用空气/液体界面培养的分化状态下。这个 实验将通过确定：IL-13是否诱导 分化为粘液表型[AIM 1]以及细胞增殖 上皮细胞[目的2]；转化生长因子-α作用的增殖需求 表皮生长因子受体与胰岛素样生长因子-2的激活--P13‘-激酶的中枢作用 在这种增殖中[目标4]；以及，初步，细胞内 (S)控制P13‘激酶诱导的细胞增殖的机制：磷酸化， 转位、与支架蛋白的相互作用和细胞的激活 循环调节酶[目标5]。这些研究将证明新奇的 黏液细胞增生发生的细胞内机制 人呼吸道上皮细胞。

DESCRIPTION (Applicant's Abstract): Mucous cell hyperplasia is common in patients with inflammatory airway diseases including asthma, COPD, bronchiectasis, and cystic fibrosis. Despite the contribution of increased mucus to airway obstruction and bacterial infection, mechanisms regulating mucous cell hyperplasia have not been elucidated. Herein, we propose that interleukin 13 (IL-13) is a key regulatory molecule controlling development of mucous cell hyperplasia. IL-13 is released by inflammatory cells at sites of injury or inflammation. It binds surface receptors of airway epithelial cells, and rapidly induces differentiation to a mucous phenotype, followed by proliferation of the mucous-producing cells. This proliferation is controlled by an IL-13-initiated intracellular signaling cascade in which phosphatidylinositol 3' kinase (Pl 3' kinase) plays a central role. The specific hypothesis to be addressed is that IL-13 elicits mucous cell proliferation via two pathways that converge to activate a single enzyme, phosphatidylinositol 3' kinase (Pl 3' kinase). These pathways include the autocrine/paracrine interaction of transforming growth factor alpha (TGF-a) with the epidermal growth factor receptor (EGF-R), and the IL-13 receptor-mediated activation of the insulin receptor substrate 2 (IRS-2). Enhanced Fl 3' kinase enzymatic activity stimulates proliferation via activation of downstream regulatory cell-cycle enzymes (e.g. p70-S6k, cdk2), resulting in an increase of mucus-producing cells. Normal human bronchial epithelial (NHBE) cells will be used as an in vitro model to address the above hypothesis. Specific culture conditions will maintain these cells so as to recreate injured epithelium in early stages of regeneration, or to model cells in the differentiated state utilizing air/liquid interface cultures. The experiments will address the hypothesis by determining: whether IL- 13 induces differentiation to a mucous phenotype [AIM 1] as well as proliferation of epithelial cells [AIM 2]; the proliferative requirement for both TGF-a acting on the EGF-R and activation of IRS-2 [AIM 3]; the central role for P1 3' kinase in this proliferation [AIM 4]; and, preliminarily, the intracellular mechanism(s) governing P1 3' kinase induced proliferation: phosphorylation, translocation, interaction with scaffolding proteins, and activation of cell cycle-regulating enzymes [AIM 5]. These studies will demonstrate novel intracellular mechanisms governing development of mucous cell hyperplasia in human airway epithelial cells.