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Glutathione mediates LPS‐stimulated COX‐2 expression via early transient p42/44 MAPK activation
Author(s) -
Chen JianXiong,
Berry Leonard C.,
Christman Brian W.,
Meyrick Barbara
Publication year - 2003
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.10353
Subject(s) - p38 mitogen activated protein kinases , glutathione , mapk/erk pathway , prostaglandin e2 , lipopolysaccharide , chemistry , kinase , protein kinase a , intracellular , prostaglandin , microbiology and biotechnology , pharmacology , biochemistry , biology , endocrinology , enzyme
This study examines whether endotoxin (LPS)‐stimulated COX‐2 is modulated by an interaction between mitogen activated protein kinases (MAPK) and intracellular glutathione. Bovine pulmonary artery endothelial cells (BPAEC) were pretreated for 30 min with the following prior to addition of 0.1 μg/ml endotoxin in 2% FBS in medium 199: 5 mM N ‐acetylcysteine (NAC) or 5 mM glutathione ethyl ester (GSE) (modulators of intracellular glutathione); 10 μM SB203580 or 25 μM PD98059 (inhibitors of p38 and p42/44 MAPKs, respectively). End‐points included assessment of COX‐1 and COX‐2 gene expression by reverse transcription polymerase chain reaction (RT‐PCR); COX‐1, COX‐2, p38, and p42/44 protein by Western analysis; and measurement of PGE 2 and 6‐keto‐PGF 1α releases by GC/MS. Both GSE and NAC resulted in significant exacerbation of the LPS‐stimulated increase in COX‐2 gene and protein expression and prostaglandin release, and suppressed the LPS‐induced decrease in COX‐1. LPS caused a biphasic activation of p42/44 MAPKs, an early increase peaking at 30 min and a second sustained phase, lasting up to 24 h; LPS also caused an early and sustained increase p38 MAPK activity. Pretreatment of cells with either GSE or NAC increased the early LPS‐stimulated activation of p42/44 but had little effect on the sustained phase. Inhibition of either p38 or p42/44 MAPKs suppressed LPS‐stimulated COX‐2 gene and protein expression, and prostaglandin release ( P < 0.05) but had little effect on COX‐1. We conclude that intracellular glutathione modulates LPS‐stimulated COX‐2 gene expression and prostaglandin synthesis in BPAEC via early activation of p42/44 MAPKs. J. Cell. Physiol. 197: 86–93, 2003© 2003 Wiley‐Liss, Inc.