Airway mucus obstruction triggers macrophage activation and matrix metalloproteinase 12-dependent emphysema.

Whereas cigarette smoking remains the main risk factor for emphysema, recent studies in β-epithelial Na(+) channel-transgenic (βENaC-Tg) mice demonstrated that airway surface dehydration, a key pathophysiological mechanism in cystic fibrosis (CF), caused emphysema in the absence of cigarette smoke exposure. However, the underlying mechanisms remain unknown. The aim of this study was to elucidate mechanisms of emphysema formation triggered by airway surface dehydration.

Membrane-bound FRET probe visualizes MMP12 activity in pulmonary inflammation.

MMP12 is a metalloproteinase implicated in inflammation. To monitor its activity, we synthesized a membrane-targeted reporter (LaRee1) based on Foerster resonance energy transfer (FRET). Unlike existing sensors, LaRee1 detects MMP12 activity by loss of FRET plus internalization of the lipidated fragment.