title: Involvement of reactive oxygen intermediates in lectin-induced protein-tyrosine phosphorylation of Syk in THP-1 cells.
abstract: Oxidative stress (H2O2) has been shown to be associated with tyrosine phosphorylation and activation of protein-tyrosine kinase Syk. In the present study, we examined the possibility that reactive oxygen intermediates (ROI) were involved in concanavalin A (Con A)-induced tyrosine phosphorylation in THP-1 cells. Rapid tyrosine phosphorylations of Syk, Fc gamma receptor(s) and phospholipase C gamma 2 (PLC gamma 2) were induced by Con A treatment in THP-1 cells. Pretreatment of cells with antioxidants N-acetylcysteine (NAC) and glutathione (GSH) almost completely blocked tyrosine phosphorylations of Syk, Fc gamma receptor(s) and PLC gamma 2. In addition, THP-1 cells showed significant levels of ROI from the early period of Con A treatment and the levels of ROI were inhibited by antioxidant treatment. These data suggest that ROI have an important role in Con A-induced protein-tyrosine kinase(s) signaling pathways.
authors.affiliation: Department of Biochemistry, Kobe University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Rezaul
authors.forename: K
authors.initials: K
authors.lastname: Sada
authors.forename: H
authors.initials: H
authors.lastname: Yamamura
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D002460:Cell Line; D003208:Concanavalin A / Q000494:pharmacology*; D004792:Enzyme Precursors / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000378:metabolism; D009000:Monocytes / Q000166:cytology / Q000187:drug effects*; D051966:Phospholipase C gamma; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D017452:Receptors, IgG / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013481:Superoxides / Q000378:metabolism; D000072377:Syk Kinase; D010738:Type C Phospholipases / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000975:Antioxidants; D004792:Enzyme Precursors; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes; D017382:Reactive Oxygen Species; D017452:Receptors, IgG; D003208:Concanavalin A; D013481:Superoxides; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D000072377:Syk Kinase; D010738:Type C Phospholipases; D051966:Phospholipase C gamma