Neutrophil Serine Protease Inhibition in Lung Diseases

Neutrophil serine proteases, principally neutrophil elastase, proteinase 3 and cathepsin G, play central roles in host defence and, when unopposed, in tissue injury across a spectrum of lung disorders. In conditions such as cystic fibrosis, chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS), excessive protease release from activated neutrophils leads to degradation of extracellular matrix, disruption of epithelial barriers and amplification of inflammation. Pharmacological strategies seek to restore protease–anti-protease balance by targeting upstream activation pathways or by direct inhibition of protease catalytic sites. Novel inhaled formulations enhance local delivery while minimising systemic exposure. Parallel efforts aim to harness endogenous inhibitors and to elucidate structural determinants of inhibitor specificity. Emerging data support the potential for protease blockade to attenuate airway remodelling, improve mucociliary clearance and reduce ventilator dependence, underscoring global relevance and opening avenues for precision-guided therapies.

Research from Nature Portfolio

Recent trials of an inhaled neutrophil elastase inhibitor in patients with cystic fibrosis demonstrated sustained improvement in mucociliary transport and a reduction in pulmonary exacerbations over twelve months, with minimal systemic absorption. Structural studies have elucidated high-resolution complexes of next-generation synthetic inhibitors bound to elastase and proteinase 3, revealing conformational ‘lock-in’ mechanisms that confer picomolar potency and exceptional selectivity. In parallel, a genome-wide screen identified a novel regulator of neutrophil degranulation whose modulation curbs the release of serine proteases in experimental ARDS, reducing alveolar barrier leakage without impairing bacterial clearance. These advances integrate translational and mechanistic insights to refine therapeutic targeting of protease-driven lung injury.

Neutrophil Serine Protease Inhibition in Lung Diseases publication trend

The graph below shows the total number of articles in neutrophil serine protease inhibition in lung diseases across all publications each year (not limited to Nature Index journals).

Technical terms

Neutrophil serine proteases: A family of enzymes (including elastase, proteinase 3, cathepsin G) released by activated neutrophils that degrade proteins and modulate inflammation.

Neutrophil elastase (NE): A key serine protease implicated in tissue destruction, mucus hypersecretion and barrier disruption in lung disease.

Protease–anti-protease balance: The equilibrium between proteolytic enzymes and their endogenous inhibitors, disruption of which leads to uncontrolled tissue damage.

Acute respiratory distress syndrome (ARDS): A severe form of acute lung injury characterised by diffuse alveolar damage, inflammation and hypoxaemia.

References

1. Neutrophil Elastase and Chronic Lung Disease. Biomolecules (2021).
2. Freezing the Bioactive Conformation to Boost Potency: The Identification of BAY 85‐8501, a Selective and Potent Inhibitor of Human Neutrophil Elastase for Pulmonary Diseases. ChemMedChem (2015).
3. Effect of a selective neutrophil elastase inhibitor on mortality and ventilator-free days in patients with increased extravascular lung water: a post hoc analysis of the PiCCO Pulmonary Edema Study. Journal of Intensive Care (2014).
4. Neutrophil elastase cleaves epithelial cadherin in acutely injured lung epithelium. Respiratory Research (2016).