0988. Human neutrophil peptides play an important role in the pathogenesis of ARDS
© Pozzi et al; licensee Springer. 2014
Published: 26 September 2014
Acute respiratory distress syndrome (ARDS) and ventilator induced lung injury (VILI) are characterized by neutrophil recruitment in the lung, and human neutrophil peptides (HNP) are the most abundant cationic proteins that are released into the extracellular matrix upon neutrophil activation. We and others have previously shown that high concentrations of HNP can lead to capillary-epithelial barrier damage in a mouse model of ARDS. We also demonstrated that VILI can lead to lung fibrotic development. We now extended the studies to examine the effects of HNP in lung remodeling.
Examine the role of HNP on lung remodeling in a mouse model of ARDS followed by mechanical ventilation.
Mice endogenously expressing HNP (HNP+/+) were generated using a human neutrophil elastase promoter. The HNP+/+and the FVB wild type mice received either HCl (pH = 1.0, 3 mL/kg) intratracheally, or vehicle solution as a control. Respiratory system compliance, protein concentrations and differential cell counting in bronchoalveolar lavage fluid (BALF) were determined 48 h after HCl. In a parallel experiment, the mice were randomized into 3 different groups 48 h after HCl: 1) no mechanical ventilation; 2) low pressure mechanical ventilation for 2 h; and 3) high pressure mechanical ventilation for 2 h. The mice were then observed for 14 days for evaluation of epithelial damage, Ashcroft score for fibrosis and inflammation.
HNP can accelerate inflammation at an early phase in a mouse model of HCl-induced ARDS, which may contribute to lung remodeling at late phases, magnifying the deleterious effects of ventilator-induced lung injury. We are hoping to present a full picture regarding lung remodeling 14 days after receiving HCl/mechanical ventilation at the ESICM conference in September.
Canadian Institute of Health Research.
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