Endogenous prostaglandin D2 synthesis reduces an increase in plasminogen activator inhibitor-1 following interleukin stimulation in bovine endothelial cells.
OBJECTIVE
We examined the role of prostaglandin D2 (PGD2) in the formation of plasminogen activator inhibitor (PAI)-1 following interleukin-1beta (IL-1) stimulation in bovine endothelial cells (EC) transfected with lipocaline-type PGD2 synthase (L-PGDS) genes.


METHODS
EC were isolated from bovine thoracic aorta and incubated with 20 U/ml IL-1 and various concentrations of authentic PGD2. The isolated EC were also transfected with L-PGDS genes by electroporation. The L-PGDS-transfected EC were used to investigate the role of endogenous PGD2 in IL-1 stimulated PAI-1 biosynthesis. We also used an anti-PGD2 antibody to examine whether an intracrine mechanism was involved in PAI-1 production. PGD2 and PAI-1 levels were determined by radio- and enzyme-immunoassay, respectively. PAI-1 mRNA was assessed by reverse transcription-polymerase chain reaction.


RESULTS
IL-1 stimulated PAI-1 production by EC was dose-dependently inhibited by authentic PGD2 at concentrations greater than 10-6 mol/l. L-PGDS gene-transfected EC produced more PGD2 than EC transfected with the reporter gene alone. IL-1 induced increases in PAI-1 production in EC transfected with reporter genes alone. However, this effect was significantly attenuated in the case of IL-1 stimulation of EC transfected with L-PGDS genes, and accompanied by an apparent suppression of PAI-1 mRNA expression. The effects of PGD2 on PAI-I formation were reversed to the basal levels by the inhibition of synthesis of endogenous PGD2. Neutralization of extracellular PGD2 by anti-PGD2 antibody influenced neither PAI-1 mRNA expression nor PAI-1 biosynthesis.


CONCLUSIONS
EC transfected with L-PGDS genes increased PGD2 synthesis. This was associated with attenuation of both PAI-1 formation and PAI-1 mRNA expression. It is suggested that endogenous PGD2 decreases PAI-1 synthesis and PAI-1 mRNA expression, probably through an intracrine mechanism.
Department of Medicine, University of Tokyo, Tokyo 113-0033, Japan. NEGORO-2IM@h.u-tokyo.ac.jp
Hideyuki
H
Negoro
Wee
W
Soo Shin
Rie
R
Hakamada-Taguchi
Naomi
N
Eguchi
Yoshihiro
Y
Urade
Atsuo
A
Goto
Teruhiko
T
Toyo-Oka
Toshiro
T
Fujita
Masao
M
Omata
Yoshio
Y
Uehara
D000818:Animals; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D007375:Interleukin-1 / Q000008:administration & dosage*; D019746:Intramolecular Oxidoreductases / Q000187:drug effects / Q000235:genetics; D054834:Lipocalins; D023421:Models, Animal; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis* / Q000235:genetics; D015230:Prostaglandin D2 / Q000096:biosynthesis* / Q000235:genetics; D011451:Prostaglandin-Endoperoxide Synthases / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection
D007375:Interleukin-1; D054834:Lipocalins; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D011451:Prostaglandin-Endoperoxide Synthases; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase; D015230:Prostaglandin D2