Figure 3.

The MRP2/HXA₃ (hepoxilin A3) axis forms the proinflammatory arm of a dynamically regulated system in which inflammatory pathways that activate responses to pathogens or aberrant signals are balanced against the anti-inflammatory P-glycoprotein (P-gp)/endocannabinoid (eCB) pathway that suppresses neutrophil responses in the context of normal commensal colonization. The 2 sets of lipid-based signaling molecules (eCB and HXA₃) are released from the apical surface during periods of either tolerance or inflammation, which control the recruitment of neutrophils to the intestinal lumen. Dysregulation of this critical balance may contribute directly to inflammatory disorders of the intestine (108).