Premium
Preferential Coupling between Cox‐2 and mPGES‐1 in Murine Endothelial Cell Line SVEC4–10
Author(s) -
Elharrrar Victor,
Konger Raymond L,
Franklin Kandice,
Corthals Stacy M,
Klaunig James E
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a228-b
Subject(s) - prostacyclin , arachidonic acid , prostaglandin , metabolite , chemistry , prostaglandin e2 , enzyme , prostaglandin e , cytoplasm , endothelial stem cell , cyclooxygenase , microbiology and biotechnology , medicine , biochemistry , endocrinology , biology , in vitro
Prostacyclin (PGI) is an endothelial regulator of vascular resistance under basal and ischemic conditions. PGI is a major metabolite of arachidonic acid (AA) and its production requires the action of Prostaglandin H synthases (Cox1, Cox2) and PGI synthase (PGIS). On inflammation, endothelial cells (EC) increase their production of prostaglandin E2 (PGE2), which is also derived from AA and requires the action of Cox1/Cox2 and of one or more PGE synthases (PGES). We tested in SVEC4–10 the hypotheses that PGI2 and PGE2 production are coupled to distinct Cox1/Cox2 enzymatic pools, and that inflammatory stimuli (LPS 50 ng/ml, IL1β5ng/ml) selectively increase PGE2 production. We also examined the localization of the prostanoids synthesis enzymes by immunofluorescence. Cells grown to confluence were exposed for 6 hrs to LPS (n=4), IL1β (n=4) or to control medium. Quantitation by real time RT‐PCR showed that SVEC4–10 constitutively express Cox1, Cox2, PGIS, and mPGES‐1. LPS and IL1β increased Cox‐2 and mPGES‐1 mRNA abundance by 80 ± 9 fold (p<0.01) but did not alter that of Cox‐1 or PGIS. LPS and IL1β increased PGE2 production, measured in the culture medium, by 3.7± 0.3 (p<0.01) and 4.6 ±.5 (p<0.01) fold but did not alter PGI production. The increase in PGE2 production was reversed by the Cox‐2 specific inhibitor NS398 (10 ‐5 M). We next demonstrated that Cox1, Cox2, PGIS, and mPGES‐1 were localized in the cytoplasm with a perinuclear distribution and that their localization was not altered by LPS treatment. These data indicate that LPS and IL1β induce selectively and in a coordinated fashion Cox‐2 and mPGES‐1 in inflammatory conditions. (Supported by NIH R01 CA 100906).