NOX2 is critical for heterotypic neutrophil-platelet interactions during vascular inflammation.
Platelet-leukocyte interactions on activated endothelial cells play an important role during microvascular occlusion under oxidative stress conditions. However, it remains poorly understood how neutrophil-platelet interactions are regulated during vascular inflammation. By using intravital microscopy with mice lacking nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) and their bone marrow chimera, we demonstrated that NOX2 from both hematopoietic and endothelial cells is crucial for neutrophil-platelet interactions during tumor necrosis factor alpha-induced venular inflammation. Platelet NOX2-produced reactive oxygen species (ROS) regulated P-selectin exposure upon agonist stimulation and the ligand-binding function of glycoprotein Ibα. Furthermore, neutrophil NOX2-generated ROS enhanced the activation and ligand-binding activity of αMβ2 integrin following N-formyl-methionyl-leucyl phenylalanine stimulation. Studies with isolated cells and a mouse model of hepatic ischemia/reperfusion injury revealed that NOX2 from both platelets and neutrophils is required for cell-cell interactions, which contribute to the pathology of hepatic ischemia/reperfusion injury. Platelet NOX2 modulated intracellular Ca(2+) release but not store-operated Ca(2+) entry (SOCE), whereas neutrophil NOX2 was crucial for SOCE but not intracellular Ca(2+) release. Different regulation of Ca(2+) signaling by platelet and neutrophil NOX2 correlated with differences in the phosphorylation of AKT, ERK, and p38MAPK. Our results indicate that platelet and neutrophil NOX2-produced ROS are critical for the function of surface receptors essential for neutrophil-platelet interactions during vascular inflammation.
Department of Pharmacology and.
Kyungho
K
Kim
Department of Pharmacology and.
Jing
J
Li
Department of Pharmacology and Department of Anesthesiology, University of Illinois College of Medicine, Chicago, IL; and.
Alan
A
Tseng
Australian Centre for Blood Diseases, Monash University, Melbourne, Australia.
Robert K
RK
Andrews
Department of Pharmacology and Department of Anesthesiology, University of Illinois College of Medicine, Chicago, IL; and.
Jaehyung
J
Cho
D000818:Animals; D001792:Blood Platelets / Q000378:metabolism* / Q000473:pathology; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000235:genetics; D002450:Cell Communication; D005260:Female; D006801:Humans; D020935:MAP Kinase Signaling System / Q000235:genetics; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D009504:Neutrophils / Q000201:enzymology* / Q000473:pathology; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014657:Vasculitis / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism
D008562:Membrane Glycoproteins; D017382:Reactive Oxygen Species; C056558:CYBB protein, human; C488842:Cybb protein, mouse; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D051057:Proto-Oncogene Proteins c-akt; D048051:p38 Mitogen-Activated Protein Kinases; D002118:Calcium