Poppinga Wilfred J, Heijink Irene H, Holtzer Laura J, Skroblin Philipp, Klussmann Enno, Halayko Andrew J, Timens Wim, Maarsingh Harm, Schmidt Martina
University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands; Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany;
University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Groningen, The Netherlands;
Am J Physiol Lung Cell Mol Physiol. 2015 Apr 15;308(8):L766-75. doi: 10.1152/ajplung.00301.2014. Epub 2015 Jan 30.
β2-Agonist inhibitors can relieve chronic obstructive pulmonary disease (COPD) symptoms by stimulating cyclic AMP (cAMP) signaling. A-kinase-anchoring proteins (AKAPs) compartmentalize cAMP signaling by establishing protein complexes. We previously reported that the β2-agonist fenoterol, direct activation of protein kinase A (PKA), and exchange factor directly activated by cAMP decrease cigarette smoke extract (CSE)-induced release of neutrophil attractant interleukin-8 (IL-8) from human airway smooth muscle (ASM) cells. In the present study, we tested the role of AKAPs in CSE-induced IL-8 release from ASM cells and assessed the effect of CSE on the expression levels of different AKAPs. We also studied mRNA and protein expression of AKAPs in lung tissue from patients with COPD. Our data show that CSE exposure of ASM cells decreases AKAP5 and AKAP12, both capable of interacting with β2-adrenoceptors. In lung tissue of patients with COPD, mRNA levels of AKAP5 and AKAP12 were decreased compared with lung tissue from controls. Using immunohistochemistry, we detected less AKAP5 protein in ASM of patients with COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II compared with control subjects. St-Ht31, which disrupts AKAP-PKA interactions, augmented CSE-induced IL-8 release from ASM cells and diminished its suppression by fenoterol, an effect mediated by disturbed ERK signaling. The modulatory role of AKAP-PKA interactions in the anti-inflammatory effects of fenoterol in ASM cells and the decrease in expression of AKAP5 and AKAP12 in response to cigarette smoke and in lungs of patients with COPD suggest that cigarette smoke-induced changes in AKAP5 and AKAP12 in patients with COPD may affect efficacy of pharmacotherapy.
β2-激动剂抑制剂可通过刺激环磷酸腺苷（cAMP）信号传导来缓解慢性阻塞性肺疾病（COPD）症状。A激酶锚定蛋白（AKAPs）通过建立蛋白质复合物使cAMP信号传导区域化。我们之前报道过，β2-激动剂非诺特罗、蛋白激酶A（PKA）的直接激活以及由cAMP直接激活的交换因子可减少香烟烟雾提取物（CSE）诱导的人气道平滑肌（ASM）细胞中中性粒细胞趋化因子白细胞介素-8（IL-8）的释放。在本研究中，我们测试了AKAPs在CSE诱导的ASM细胞IL-8释放中的作用，并评估了CSE对不同AKAPs表达水平的影响。我们还研究了COPD患者肺组织中AKAPs的mRNA和蛋白表达。我们的数据表明，ASM细胞暴露于CSE会降低AKAP5和AKAP12，这两者都能够与β2-肾上腺素能受体相互作用。在COPD患者的肺组织中，与对照组肺组织相比，AKAP5和AKAP12的mRNA水平降低。使用免疫组织化学方法，我们检测到与对照受试者相比，慢性阻塞性肺疾病全球倡议（GOLD）II期COPD患者的ASM中AKAP5蛋白较少。破坏AKAP-PKA相互作用的St-Ht31增强了CSE诱导的ASM细胞IL-8释放，并减弱了非诺特罗对其的抑制作用，这一效应由紊乱的ERK信号传导介导。AKAP-PKA相互作用在非诺特罗对ASM细胞的抗炎作用中的调节作用以及对香烟烟雾和COPD患者肺部中AKAP5和AKAP12表达降低的影响表明，香烟烟雾诱导的COPD患者中AKAP5和AKAP12的变化可能会影响药物治疗的疗效。
