Discrete generations of intracellular hydrogen peroxide and superoxide in antigen-stimulated mast cells: reciprocal regulation of store-operated Ca2+ channel activity

Mol Immunol. 2009 Jul;46(11-12):2200-9. doi: 10.1016/j.molimm.2009.04.013. Epub 2009 May 20.

Abstract

Mast cells and T cells produce reactive oxygen species (ROS) after stimulation with the high-affinity IgE receptor (Fc epsilon RI) and T cell receptor. A growing body of evidence suggests the existence of ROS-regulated intracellular and/or plasma membrane Ca(2+) channels in these cells but their molecular entities remain to be identified. Here, we report that store-operated Ca(2+) channel (SOC) activity is regulated by superoxide (O(2)(*-)) and hydrogen peroxide (H(2)O(2)) in mast cells. MnTBaP (Mn(III)tetrakis(4-benzoic acid)porphyrin) and ebselen (2-phenyl-1,2-benziso-selenazol-3(2H)-one) selectively blocked the generation of O(2)(*-) and H(2)O(2), respectively, in antigen-stimulated cells. The H(2)O(2) generation was dependent on the Src family kinase (SFK) and phosphatidylinositol-3-kinase (PI3K) activities but independent of extracellular Ca(2+), and the Fc epsilon RI beta-chain immunoreceptor tyrosine-based activation motif played an essential role. On the other hand, O(2)(*-) generation was strictly dependent on extracellular Ca(2+), but negatively regulated by the SFK and PI3K activities. Inhibition of O(2)(*-) generation resulted in increased H(2)O(2) generation and reduced SOC activity, although it had a minimal effect on endoplasmic reticulum Ca(2+) store depletion. On the contrary, inhibition of H(2)O(2) generation resulted in increased intracellular O(2)(*-) generation and augmented SOC activity. The findings suggest that O(2)(*-) and H(2)O(2), which are generated by separate signaling pathways/sources, reciprocally regulate SOC activity in mast cells. Such generations of multiple oxidant species and their distinct roles in the regulation of SOC activity may facilitate the fine tuning of Ca(2+) signaling in mast cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Azoles / pharmacology
  • Calcium / physiology
  • Calcium Channels / physiology*
  • Cell Degranulation / drug effects
  • Cell Degranulation / physiology
  • Cell Line, Tumor
  • Endoplasmic Reticulum / metabolism
  • Extracellular Space / metabolism
  • Hydrogen Peroxide / metabolism*
  • Mast Cells / drug effects
  • Mast Cells / immunology*
  • Mast Cells / physiology
  • Mice
  • Mice, Knockout
  • Organoselenium Compounds / pharmacology
  • Phosphatidylinositol 3-Kinases / physiology
  • Porphyrins / pharmacology
  • Rats
  • Receptors, IgE / genetics
  • Receptors, IgE / physiology
  • Superoxides / metabolism*
  • src-Family Kinases / physiology

Substances

  • Azoles
  • Calcium Channels
  • Fc-epsilon receptor I beta-chain, mouse
  • Organoselenium Compounds
  • Porphyrins
  • Receptors, IgE
  • tetrakis(4-benzoic acid)porphyrin
  • Superoxides
  • ebselen
  • Hydrogen Peroxide
  • Phosphatidylinositol 3-Kinases
  • src-Family Kinases
  • Calcium