title: Oxidative stress suppresses cysteinyl leukotriene generation by mouse bone marrow-derived mast cells.
abstract: Cysteinyl leukotrienes and oxidative stress have both been implicated in bronchial asthma; however, there is no previous study that focused on the ability of oxidative stress to alter cysteinyl leukotriene generation. In this study, treatment of bone marrow-derived mast cells with prostaglandin D(2) reduced their ability to generate leukotriene (LT) C(4) upon calcium ionophore stimulation but had little effect on LTB(4) generation. This effect could be reproduced by a selective agonist of the DP(2) receptor, 15R-methyl prostaglandin D(2) (15R-D(2)). 15R-D(2) dose-dependently inhibited LTC(4) generation with an IC(50) of 2 μM, and the effect was not altered by a DP(2)/thromboxane antagonist or by a peroxisome proliferator-activated receptor-γ antagonist. 15R-D(2) exerted its suppressive effect via a reduction in intracellular GSH, a mechanism that involved the conjugation of its non-enzymatic breakdown product to GSH. At 10 μM, 15R-D(2) reduced LTC(4) generation to 10%, intracellular GSH to 50%, and LTC(4) synthase (LTC(4)S) activity to 33.5% of untreated cells without altering immunoreactive LTC(4)S protein expression or 5-lipoxygenase activity. The effects of 15R-D(2) on LTC(4)S activity could be partially reversed by reducing reagent. The sulfhydryl-reactive oxidative agent diamide suppressed LTC(4)S activity and induced a reversible formation of covalent dimer LTC(4)S. LTC(4)S bearing a C56S mutation was resistant to the effect of diamide. Covalent dimer LTC(4)S was observed in nasal polyp biopsies, indicating that dimerization and inactivation of LTC(4)S can occur at the site of inflammation. These results suggest a cellular redox regulation of LTC(4)S function through a post-translational mechanism.
authors.affiliation: From the Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
authors.forename: Ping
authors.initials: P
authors.lastname: He
authors.affiliation: From the Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
authors.forename: Tanya
authors.initials: T
authors.lastname: Laidlaw
authors.affiliation: From the Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
authors.forename: Akiko
authors.initials: A
authors.lastname: Maekawa
authors.affiliation: From the Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Kanaoka
authors.affiliation: From the Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
authors.forename: Kongyi
authors.initials: K
authors.lastname: Xu
authors.affiliation: From the Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115. Electronic address: blam@rics.bwh.harvard.edu.
authors.forename: Bing K
authors.initials: BK
authors.lastname: Lam
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism*; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007975:Leukotriene B4 / Q000235:genetics / Q000378:metabolism; D017997:Leukotriene C4 / Q000096:biosynthesis* / Q000235:genetics; D008407:Mast Cells / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D015230:Prostaglandin D2 / Q000378:metabolism / Q000494:pharmacology
chemical_list: D007975:Leukotriene B4; D017997:Leukotriene C4; D005982:Glutathione Transferase; C041116:leukotriene-C4 synthase; D015230:Prostaglandin D2