To reach the sites of inflammation, neutrophils traverse the endothelium, its underlying basement membrane, and other barriers depending on the localization of the insulting agent. Whether neutrophil elastase (NE) plays a role in neutrophil recruitment to inflamed sites is still debatable. By exploiting mice deficient in NE (NE(-/-)), we sought to address this dilemma. We recruited neutrophils ...

Fischer BM, Zheng S, Fan R, Voynow JA. Neutrophil elastase inhibition of cell cycle progression in airway epithelial cells in vitro is mediated by p27. Am J Physiol Lung Cell Mol Physiol 293: L762–L768, 2007. First published June 22, 2007; doi:10.1152/ajplung.00067.2007.—Neutrophil elastase (NE), a serine protease present in high concentrations in the airways of cystic fibrosis patients, injure...

This study examined the role of cysteine proteinases and their inhibitor in the development of emphysema in comparison with neutrophil elastase (NE) complexed with alpha1-protease inhibitor (NE-alpha1-PI), which was previously demonstrated to be increased in bronchoalveolar lavage (BAL) fluid from subjects with subclinical emphysema. Eight nonsmokers and 31 current smokers with (n=17) and witho...

Neutrophil infiltration is the characteristic pathological feature of M. pneumoniae pneumonia (MPP). This study aimed to explore the associations among neutrophil activity, clinical presentation, and role of the M. pneumoniae/interleukin-8 (IL-8)/neutrophil axis in the pathogenesis of MPP. A total of 42 patients with MPP were prospectively enrolled in the study. Neutrophil activity, including m...

Several lines of evidence, albeit most of them circumstant ia l, support the protease-antiprotease imbalance concept in the pathogenesis of emphysema. Neutrophil elastase (NE) has become the key enzyme for several reasons. NE is insufficiently inhibited by a( antitrypsin (AAT) (a 1 -proteinase inhibitor) in inherited deficiency states when the extracellular level of the predominant antiprotease...

To address the role of neutrophil elastase in pulmonary emphysema, neutrophil elastase-deficient mice and wild-type littermate controls were exposed to long-term cigarette smoke. Compared to wild-type littermates, mice that were deficient in neutrophil elastase were significantly protected (59%) from the development of emphysema. Previously, we demonstrated complete protection from emphysema in...

Neutrophils release decondensed chromatin termed neutrophil extracellular traps (NETs) to trap and kill pathogens extracellularly. Reactive oxygen species are required to initiate NET formation but the downstream molecular mechanism is unknown. We show that upon activation, neutrophil elastase (NE) escapes from azurophilic granules and translocates to the nucleus, where it partially degrades sp...

A highly specific, fluorogenic probe detects human neutrophil elastase (hNE) in activated neutrophils and Neutrophil Extracellular Traps (NETs).

Neutrophil dysfunction, resulting in inefficient bacterial clearance, is a feature of several serious medical conditions, including cystic fibrosis (CF) and sepsis. Poorly controlled neutrophil serine protease (NSP) activity and complement activation have been implicated in this phenomenon. The capacity for excess NSP secretion and complement activation to influence the expression and function ...