Platelet specific knockout of integrin beta-3 (β3) reduces severity of necrotizing enterocolitis in murine neonates.

INTRODUCTION: Necrotizing Enterocolitis (NEC) is the most impactful gastrointestinal disease of premature neonates and preclinical evidence shows that the event of platelet activation is an important pathophysiological contributor during NEC-like injury in murine neonates. Integrin αIIb/β3 (glycoprotein [GP]IIb/IIIa) is the primary platelet activation marker showing increased platelet-monocytes aggregation during NEC-like injury. The present study investigates whether platelet lineage-specific deletion of integrin-β3 reduces NEC-like injury in murine neonates. METHODS: C57BL/6 and integrin-β3(-/-) mouse pups were subjected to trinitrobenzene sulfonic acid (TNBS)-induced NEC-like injury (n = 6/each group). Monocyte-platelet aggregation was measured by flow cytometry and immunofluorescence. Plasma levels of intestinal injury markers (FABP2, CRP, CXCL2 and SAA) and inflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-1α) were measured by ELISA and multiplex array respectively. Intestinal inflammatory responses were confirmed by qRT-PCR. RESULTS: Integrin-β3-associated platelet-monocyte aggregation was significantly observed in the intestine and blood of murine NEC-like injury and in the human NEC intestine. Platelet-specific deletion of integrin-β3's exon-1 leads to inhibition of platelet-monocyte aggregation in circulating blood and intestine, thus reducing the resulting intestinal injury and the level of inflammatory activation cytokines in the blood. CONCLUSION: Monocyte-platelet aggregation is an important pathophysiological event and the blockade of integrin-β3 merits a potential therapeutic target in NEC.