Hypotonic stress increases cyclooxygenase-2 expression and prostaglandin release from amnion-derived WISH cells.
This report examines the effect of cell volume expansion on cyclooxygenase-2 (COX-2) mRNA expression, COX-2 protein expression, and prostaglandin E2 release from human amnion-derived WISH cells. Earle's balanced salts solution (EBSS) with limited NaCl concentration was utilized as the induction medium. COX-2 mRNA was elevated 6-fold in cells incubated for 1 h in hypotonic EBSS. COX-2 mRNA expression was not increased when raffinose or sucrose were used to reconstitute low NaCl. Actinomycin D blocked COX-2 mRNA increase by hypotonic stress, while cycloheximide enhanced COX-2 mRNA expression. COX-2 mRNA and protein concentrations increased as a function of decreasing media osmolarity and incubation time in hypotonic EBSS. Hypotonic EBSS induced a 3-fold increase in prostaglandin E2 release. WISH cells transiently transfected with a luciferase expression vector driven by the human COX-2 promoter for the COX-2 gene show a 3-fold increase in luciferase activity when incubated in hypotonic EBSS. COX-2 mRNA levels in primary human amnion cells were also increased by hypotonic stress. This study suggests that amnion cell COX-2 gene expression is regulated by cell volume expansion and/or increased plasma membrane tension.
Lundgren
D W
DW
Labor Focus Research Group, Case Western Reserve University School of Medicine, MetroHealth Medical Center, Cleveland, Ohio 44109, USA.
Moore
R M
RM
Collins
P L
PL
Moore
J J
JJ
D000650:Amnion / Q000166:cytology* / Q000378:metabolism; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D051546:Cyclooxygenase 2; D003609:Dactinomycin / Q000494:pharmacology; D015232:Dinoprostone / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins; D009997:Osmotic Pressure; D011401:Promoter Regions, Genetic; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D011453:Prostaglandins / Q000096:biosynthesis*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism
D007527:Isoenzymes; D008565:Membrane Proteins; D011453:Prostaglandins; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D003609:Dactinomycin; D003513:Cycloheximide; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone