Department of Thoracic Medicine and Surgery, Temple University, Philadelphia, PA, 19140, United States.
Center for Inflammation, Translational and Clinical Lung Research, Temple University, Philadelphia, PA, 19140, United States.
Sci Rep. 2018 Feb 23;8(1):3555. doi: 10.1038/s41598-018-21790-3.
Emphysema is characterized by irreversibly enlarged airspaces and destruction of alveolar walls. One of the factors contributing to this disease pathogenesis is an elevation in extracellular matrix (ECM) degradation in the lung. Alveolar type II (ATII) cells produce and secrete pulmonary surfactants and proliferate to restore the epithelium after damage. We isolated ATII cells from control non-smokers, smokers and patients with emphysema to determine the role of NFE2 (nuclear factor, erythroid-derived 2). NFE2 is a heterodimer composed of two subunits, a 45 kDa (p45 NFE2) and 18 kDa (p18 NFE2) polypeptides. Low expression of p45 NFE2 in patients with emphysema correlated with a high ECM degradation. Moreover, we found that NFE2 knockdown increased cell death induced by cigarette smoke extract. We also studied the cross talk between p45 NFE2 and DJ-1. DJ-1 protein is a redox-sensitive chaperone that protects cells from oxidative stress. We detected that cigarette smoke significantly increased p45 NFE2 levels in DJ-1 KO mice compared to wild-type mice. Our results indicate that p45 NFE2 expression is induced by exposure to cigarette smoke, has a cytoprotective activity against cell injury, and its downregulation in human primary ATII cells may contribute to emphysema pathogenesis.
肺气肿的特征是不可逆的气腔扩大和肺泡壁破坏。导致这种疾病发病机制的因素之一是肺细胞外基质(ECM)降解的升高。肺泡 II 型(ATII)细胞产生并分泌肺表面活性剂,并在损伤后增殖以修复上皮。我们从非吸烟者、吸烟者和肺气肿患者中分离出 ATII 细胞,以确定核因子红细胞衍生 2(NFE2)的作用。NFE2 是由两个亚基组成的异二聚体,一个 45kDa(p45NFE2)和 18kDa(p18NFE2)多肽。肺气肿患者中 p45NFE2 的低表达与 ECM 降解的增加相关。此外,我们发现 NFE2 敲低增加了香烟烟雾提取物诱导的细胞死亡。我们还研究了 p45NFE2 和 DJ-1 之间的串扰。DJ-1 蛋白是一种对氧化应激具有保护作用的氧化还原敏感伴侣。我们发现与野生型小鼠相比,香烟烟雾显著增加了 DJ-1 KO 小鼠中的 p45NFE2 水平。我们的结果表明,p45NFE2 的表达是由香烟烟雾暴露诱导的,对细胞损伤具有细胞保护活性,其在人原发性 ATII 细胞中的下调可能导致肺气肿的发病机制。