Lipoxins and aspirin-triggered lipoxins in neutrophil adhesion and signal transduction.
Lipoxin A4 (LXA4) and aspirin-triggered 15-epi-LXA4 (ATL) are emerging as endogenous braking signals for neutrophil-mediated tissue injury. LXA4 and ATL and their metabolically stable analogues display potent inhibitory actions in human isolated cells and blood, including attenuation of expression of adhesion molecules on leukocytes and endothelial cells, neutrophil adhesion to endothelial cells and platelets under shear, and IL-8 production, key events of the acute inflammatory response. The underlying molecular mechanisms include interference with MAPK signaling pathways, modulation of the oxidative chemistry of superoxide, NO and ONOO-, inhibition of activation of NF-kappaB and AP-1, and consequently the expression of interleukin-8 and likely other pro-inflammatory genes. Collectively, these results add to the profile of LXA4/ATL rapid actions that contribute to "stop signaling" involved in regulating neutrophil functions during acute inflammation and suggest that aspirin inhibits neutrophil accumulation through triggering the synthesis of 15-epi-LXA4.
Research Center, Maisonneuve-Rosemont Hospital, University of Montreal, 5415 boulevard de l'Assomption, Montreal, Que., Canada H1T 2M4. janos.g.filep@umontreal.ca
János G
JG
Filep
Tarek
T
Khreiss
Levente
L
József
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001241:Aspirin / Q000494:pharmacology; D002448:Cell Adhesion / Q000502:physiology; D006801:Humans; D007249:Inflammation / Q000503:physiopathology; D044045:Lipoxins / Q000502:physiology*; D018375:Neutrophil Activation / Q000502:physiology; D009504:Neutrophils / Q000502:physiology*; D030421:Peroxynitrous Acid / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D044045:Lipoxins; C040527:lipoxin A4; D030421:Peroxynitrous Acid; D001241:Aspirin