Involvement of receptor aggregation and reactive oxygen species in osmotic stress-induced Syk activation in B cells.
Syk has been shown to be activated by osmotic stress, however, the mechanisms involved are largely unknown. In this study, we demonstrated that cell shrinkage, rather than osmolarity, was responsible for osmotic stress-induced Syk activation. Osmotic stress-induced Syk activation depended partly upon aggregation of surface receptors. Moreover, intracellular reactive oxygen species were involved in mediating osmotic stress-induced Syk activation, with osmotic stress-induced Syk activation being inhibited by the pretreatment of cells with N-acetyl-cysteine and reduced glutathione. When cells were treated with the combination of sodium chloride and hydrogen peroxide, there was a synergistic activation of Syk. In conclusion, osmotic stress-induced Syk activation required suramin-inhibitable surface receptor aggregation and accumulation of intracellular reactive oxygen species.
Qin
S
S
Department of Biochemistry, Kobe University School of Medicine, Chuo-ku, Kobe, 650-0017, Japan.
Ding
J
J
Takano
T
T
Yamamura
H
H
D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism*; D002460:Cell Line; D048429:Cell Size / Q000187:drug effects; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects; D004792:Enzyme Precursors / Q000378:metabolism*; D005978:Glutathione / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D009994:Osmolar Concentration; D018384:Oxidative Stress / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D019000:Phosphotyrosine / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011940:Receptor Aggregation / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology; D013498:Suramin / Q000494:pharmacology; D013552:Swine; D000072377:Syk Kinase
D000975:Antioxidants; D004792:Enzyme Precursors; D047908:Intracellular Signaling Peptides and Proteins; D017382:Reactive Oxygen Species; D019000:Phosphotyrosine; D012965:Sodium Chloride; D013498:Suramin; D011189:Potassium Chloride; D006861:Hydrogen Peroxide; D011505:Protein-Tyrosine Kinases; C000606896:SYK protein, human; D000072377:Syk Kinase; D005978:Glutathione; D000111:Acetylcysteine