Ngkelo Anta, Hoffmann Roland F, Durham Andrew L, Marwick John A, Brandenburg Simone M, de Bruin Harold G, Jonker Marnix R, Rossios Christos, Tsitsiou Eleni, Caramori Gaetano, Contoli Marco, Casolari Paolo, Monaco Francesco, Andò Filippo, Speciale Giuseppe, Kilty Iain, Chung Kian F, Papi Alberto, Lindsay Mark A, Ten Hacken Nick H T, van den Berge Maarten, Timens Wim, Barnes Peter J, van Oosterhout Antoon J, Adcock Ian M, Kirkham Paul A, Heijink Irene H
Airways Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom;
University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Groningen, The Netherlands;
Am J Physiol Lung Cell Mol Physiol. 2015 Nov 15;309(10):L1112-23. doi: 10.1152/ajplung.00077.2015. Epub 2015 Aug 28.
In chronic obstructive pulmonary disease (COPD), oxidative stress regulates the inflammatory response of bronchial epithelium and monocytes/macrophages through kinase modulation and has been linked to glucocorticoid unresponsiveness. Glycogen synthase-3β (GSK3β) inactivation plays a key role in mediating signaling processes upon reactive oxygen species (ROS) exposure. We hypothesized that GSK3β is involved in oxidative stress-induced glucocorticoid insensitivity in COPD. We studied levels of phospho-GSK3β-Ser9, a marker of GSK3β inactivation, in lung sections and cultured monocytes and bronchial epithelial cells of COPD patients, control smokers, and nonsmokers. We observed increased levels of phospho-GSK3β-Ser9 in monocytes, alveolar macrophages, and bronchial epithelial cells from COPD patients and control smokers compared with nonsmokers. Pharmacological inactivation of GSK3β did not affect CXCL8 or granulocyte-macrophage colony-stimulating factor (GM-CSF) expression but resulted in glucocorticoid insensitivity in vitro in both inflammatory and structural cells. Further mechanistic studies in monocyte and bronchial epithelial cell lines showed that GSK3β inactivation is a common effector of oxidative stress-induced activation of the MEK/ERK-1/2 and phosphatidylinositol 3-kinase/Akt signaling pathways leading to glucocorticoid unresponsiveness. In primary monocytes, the mechanism involved modulation of histone deacetylase 2 (HDAC2) activity in response to GSK3β inactivation. In conclusion, we demonstrate for the first time that ROS-induced glucocorticoid unresponsiveness in COPD is mediated through GSK3β, acting as a ROS-sensitive hub.
在慢性阻塞性肺疾病（COPD）中，氧化应激通过激酶调节来调控支气管上皮细胞和单核细胞/巨噬细胞的炎症反应，并且与糖皮质激素无反应性有关。糖原合酶-3β（GSK3β）失活在介导活性氧（ROS）暴露后的信号传导过程中起关键作用。我们推测GSK3β参与了COPD中氧化应激诱导的糖皮质激素不敏感性。我们研究了COPD患者、对照吸烟者和非吸烟者的肺组织切片、培养的单核细胞及支气管上皮细胞中磷酸化GSK3β-Ser9（GSK3β失活的标志物）的水平。我们观察到，与非吸烟者相比，COPD患者和对照吸烟者的单核细胞、肺泡巨噬细胞及支气管上皮细胞中磷酸化GSK3β-Ser9水平升高。GSK3β的药理学失活不影响CXCL8或粒细胞-巨噬细胞集落刺激因子（GM-CSF）的表达，但在体外导致炎症细胞和结构细胞出现糖皮质激素不敏感性。对单核细胞和支气管上皮细胞系进行的进一步机制研究表明，GSK3β失活是氧化应激诱导的MEK/ERK-1/2和磷脂酰肌醇3-激酶/Akt信号通路激活导致糖皮质激素无反应性的共同效应器。在原代单核细胞中，该机制涉及响应GSK3β失活对组蛋白去乙酰化酶2（HDAC2）活性的调节。总之，我们首次证明COPD中ROS诱导的糖皮质激素无反应性是通过作为ROS敏感枢纽的GSK3β介导的。
