Murphy Mark P, McEnery Thomas, McQuillan Karen, McElvaney Oisín F, McElvaney Oliver J, Landers Sarah, Coleman Orla, Bussayajirapong Anchalin, Hawkins Padraig, Henry Michael, Meleady Paula, Reeves Emer P, McElvaney Noel G
Irish Centre for Genetic Lung Disease, Dept of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland.
National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin, Ireland.
Eur Respir J. 2020 Apr 30;55(4). doi: 10.1183/13993003.01678-2019. Print 2020 Apr.
Obstructive pulmonary disease in patients with α antitrypsin (AAT) deficiency (AATD) occurs earlier in life compared with patients without AATD. To understand this further, the aim of this study was to investigate whether AATD presents with altered neutrophil characteristics, due to the specific lack of plasma AAT, compared with non-AATD COPD.This study focussed on the neutrophil plasma membrane and, by use of label-free tandem mass spectrometry, the proteome of the neutrophil membrane was compared in forced expiratory volume in 1 s (FEV)-matched AATD, non-AATD COPD and in AATD patients receiving weekly AAT augmentation therapy (n=6 patients per cohort). Altered protein expression in AATD was confirmed by Western blot, ELISA and fluorescence resonance energy transfer analysis.The neutrophil membrane proteome in AATD differed significantly from that of COPD as demonstrated by increased abundance and activity of primary granule proteins including neutrophil elastase on the cell surface in AATD. The signalling mechanism underlying increased degranulation involved Rac2 activation, subsequently resulting in proteinase-activated receptor 2 activation by serine proteinases and enhanced reactive oxygen species production. and , AAT reduced primary granule release and the described plasma membrane variance was resolved post-AAT augmentation therapy , the effects of which significantly altered the AATD neutrophil membrane proteome to that of a non-AATD COPD cell.These results provide strong insight into the mechanism of neutrophil driven airways disease associated with AATD. Therapeutic AAT augmentation modified the membrane proteome to that of a typical COPD cell, with implications for clinical practice.
与无α1抗胰蛋白酶（AAT）缺乏症（AATD）的患者相比，AATD患者的阻塞性肺疾病在生命早期就会出现。为了进一步了解这一情况，本研究的目的是调查与非AATD慢性阻塞性肺疾病（COPD）相比，AATD是否由于血浆AAT的特异性缺乏而呈现出中性粒细胞特征的改变。本研究聚焦于中性粒细胞膜，并通过无标记串联质谱法，比较了1秒用力呼气量（FEV）匹配的AATD患者、非AATD COPD患者以及接受每周一次AAT补充治疗的AATD患者（每组6例患者）中性粒细胞膜的蛋白质组。通过蛋白质印迹法、酶联免疫吸附测定法和荧光共振能量转移分析证实了AATD中蛋白质表达的改变。AATD患者的中性粒细胞膜蛋白质组与COPD患者的有显著差异，表现为AATD患者细胞表面包括中性粒细胞弹性蛋白酶在内的初级颗粒蛋白丰度和活性增加。脱颗粒增加的潜在信号传导机制涉及Rac2激活，随后导致丝氨酸蛋白酶激活蛋白酶激活受体2并增强活性氧生成。此外，AAT减少了初级颗粒释放，并且在AAT补充治疗后上述细胞膜差异得到解决，其效果显著改变了AATD中性粒细胞膜蛋白质组，使其与非AATD COPD细胞的膜蛋白质组相似。这些结果为深入了解与AATD相关的中性粒细胞驱动的气道疾病机制提供了有力依据。治疗性AAT补充将膜蛋白质组改变为典型COPD细胞的膜蛋白质组，对临床实践具有重要意义。
