Phosphoinositide 3-Kinase Mediates Calcium Sensitization in Human Airway Smooth Muscle

呼吸道高反应性(AHR)和炎症，哮喘的特征，暴露于 对环境的侮辱，如过敏原和毒物。治疗的主要手段包括抗炎。 药物和支气管扩张剂，逆转人类呼吸道平滑肌(HASM)的缩短。然而， 大约一半的哮喘患者目前的治疗方法控制不充分，需要新药。我们的 数据表明，HASM的缩短依赖于磷脂酰肌醇3-激酶(PI3K)，一种激酶 参与多种细胞功能。我们还表明，抑制PI3K导致支气管扩张。 人类航空公司。然而，PI3K在平滑肌收缩和松弛中的作用仍然存在 未知。由于PI3K/RhoA/Rho Kinase(ROCK)轴调节激动剂介导的HASM缩短，即 假设PI3K激活增加了钙敏感性，从而放大了缩短和 在哮喘中驾驶AHR。使用hPCLS收缩分析、岩石活化分析、 基于细胞培养中氨基酸的稳定同位素标记(SILAC)的定量磷酸蛋白质组学，以及 定量分析单个HASM细胞力量的产生，我将确定PI3K在调制中的作用 呼吸道平滑肌缩短。我的目标是(1)研究PI3K是否调节激动剂诱导的呼吸道 通过增加HASM中对钙的敏感性来实现支气管收缩；以及(2)确定哮喘是否 调节HASM中的钙敏化途径。这些目标的实现将提供更深层次的 对哮喘AHR驱动机制的理解。理想情况下，了解分子途径 调节HASM中的钙增敏作用将为支气管扩张剂治疗寻找新的治疗方法。

Airway hyper-responsiveness (AHR) and inflammation, hallmarks of asthma, manifest upon exposure to environmental insults such as allergens and toxicants. The mainstay of treatment includes anti-inflammatory agents and bronchodilators, which reverse shortening of human airway smooth muscle (HASM). However, about half of patients with asthma have inadequate control with current therapies and require novel drugs. Our data suggests that HASM shortening is dependent upon phosphatidylinositol 3-kinase (PI3K), a kinase involved in a variety of cellular functions. We also show that inhibition of PI3K results in the bronchodilation of human airways. However, the role of PI3K in smooth muscle contraction and relaxation remains unknown. Since the PI3K/RhoA/Rho Kinase (ROCK) axis modulates agonist-mediated HASM shortening, I hypothesize that PI3K activation increases calcium sensitivity, thereby amplifying shortening and driving AHR in asthma. Using techniques such as hPCLS contraction assays, ROCK activation assays, stable isotope labeling by amino acids in cell culture (SILAC) based quantitative phosphoproteomics, and quantitative analysis of single HASM cell force generation, I will determine the role of PI3K in modulating airway smooth muscle shortening. I aim to (1) Investigate whether PI3K modulates agonist-induced airway bronchoconstriction by increasing sensitivity to calcium in HASM; and (2) Determine whether asthma modulates calcium sensitization pathways in HASM. Completion of these aims will provide a deeper understanding of mechanisms driving AHR in asthma. Ideally, understanding the molecular pathways modulating calcium sensitization in HASM will identify novel therapeutics for bronchodilator therapy.