ATP Modulates Acute Inflammation In Vivo through Dual Oxidase 1–Derived H2O2 Production and NF-κB Activation

Abstract

Dual oxidase 1 (Duox1) is the NADPH oxidase responsible for the H2O2 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 H2O2 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 H2O2 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 H2O2, 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.

Matrix metalloproteinase 9 modulates collagen matrices and wound repair

“…4C). This is in agreement with a recent report that identified increased NFκB activity after wounding in zebrafish larvae downstream of wound-induced H 2 O 2 de Oliveira et al, 2014). Because early wound signals like H 2 O 2 have been shown to modulate regeneration (Yoo et al, 2012), we sought to determine whether NFκB activation was required for mmp9 expression.…”

TRPV4-Mediated Detection of Hyposmotic Stress by Skin Keratinocytes Activates Developmental Immunity

“…In contrast, PLA2 and noncanonical arachidonate metabolites, via a 5-oxo-ETE receptor, have been shown to mediate hyposmolarity-induced leukocyte chemotaxis and rapid leukocyte recruitment to sites of tissue damage in zebrafish (45). These differences might be explained by the absence of tissue damage and, therefore, full barrier integrity in newly hatched embryos compared with a local wounded tissue where DAMPs are rapidly released, such as ATP that activates purinergic receptors and signals through alternate pathways (46,47). Unfortunately, we failed to determine the contribution of PLC downstream TRPV4 activation, because pharmacological inhibition of PLC drastically induced IL-1b transcript levels, probably reflecting the essential role of PLC-d1 in skin stem cell lineage commitment (48), which results in the induction of inflammation in PLC-d1-deficient mice (49).…”

Duox1-Derived H2O2 Modulates Cxcl8 Expression and Neutrophil Recruitment via JNK/c-JUN/AP-1 Signaling and Chromatin Modifications

“…Additionally, it has been shown in vitro that H 2 O 2 is able to modulate the function of redox-sensitive transcription factors (13,14) and to influence the gene expression of proinflammatory molecules, such as IL-1b or CXCL8 (15)(16)(17)(18). Recently, we have further reported that Duox1-derived H 2 O 2 is involved in NF-kB activation in wound healing (19). Importantly, we have also found that CXCL8 zebrafish homologs, Cxcl8-l1 and Cxcl8-l2, are crucial for neutrophil recruitment upon wounding and that they are able to dictate neutrophil behavior and to influence later tissue regeneration in zebrafish larvae (10).…”