ATP modulates acute inflammation in vivo through dual oxidase 1-derived H₂O₂ production and NF-κB activation

Dual oxidase 1 (Duox1) is the NADPH oxidase responsible for the H ₂O₂ gradient formed in tissues after injury to trigger the early recruitment of leukocytes. Little is known about the signals that modulate H₂O₂ release from DUOX1 and whether the H ₂O₂ gradient can orchestrate the inflammatory response in vivo. In this study, we report on a dominant-negative form of zebrafish Duox1 that is able to inhibit endogenous Duox1 activity, H₂O₂ release and leukocyte recruitment after tissue injury, with none of the side effects associated with morpholino-mediated Duox1 knockdown. Using this specific tool, we found that ATP release following tissue injury activates purinergic P2Y receptors, and modulates Duox1 activity through phospholipase C (PLC) and intracellular calcium signaling in vivo. Furthermore, Duox1-derived H ₂O₂ is able to trigger the NF-κB inflammatory signaling pathway. These data reveal that extracellular ATP acting as an early danger signal is responsible for the activation of Duox1 via a P2YR/PLC/Ca ²⁺ signaling pathway and the production of H₂O ₂, which, in turn, is able to modulate in vivo not only the early recruitment of leukocytes to the wound but also the inflammatory response through activation of the NF-κB signaling pathway.