NEC is a NETs dependent process and markers of NETosis are predictive of NEC in mice and humans

Abstract

Introduction: NEC is one of the most devastating diseases affecting premature and mature infants. It is hypothesized that NEC is the result of neutrophils’ active role in hyperinflammation after bacterial gut colonization, as they release nuclear DNA and form NETs to combat pathogens. The aim of this study was to evaluate NETs’ role in NEC pathogenesis, and to identify markers of NETosis to predict NEC. Methods: NEC was induced in mice by gavage feeding Neocate/LPS, followed by a hypoxia phase q12h for 5 days, starting on day 4 p.p.. The interrelation of NEC and neutrophils, including NETs, was assessed macroscopically, microscopically, and in blood samples. To determine the exact role of NETs in NEC pathogenesis, a PAD-inhibition model was established. Human intestinal samples of diagnostically verified NEC were also analyzed. Results: Our results suggest that the hyperinflammation observed in NEC is a NETs-dependent process, as NEC severity was significantly reduced in mice incapable of forming NETs, and markers for NEC and NETs correlated positively. Further, serum NETosis biomarkers appear to predict NEC in mice. As findings of the mouse NEC model correlate positively with human NEC samples, the hyperinflammation reaction observed in mice could potentially be applied to human NEC pathogenesis.