title: Induction of cyclooxygenase-2 and prostaglandin F2alpha receptor expression by interleukin-1beta in cultured human granulosa-luteal cells.
abstract: Prostanoids are important regulators of ovarian function, especially during ovulation and luteolysis. Cyclooxygenase (Cox) is the rate-limiting enzyme in conversion of arachidonic acid to prostanoids. We have examined the expression and regulation of the inducible Cox isoform (Cox-2) and of the receptor for PGF2alpha (FP) in human granulosa cells obtained from women undergoing oocyte retrieval for in vitro fertilization. Freshly isolated granulosa cells express Cox-2 and FP receptor messenger RNAs (mRNAs). FP receptor mRNA is also expressed in cultured human granulosa-luteal (GL) cells, but Cox-2 transcripts are expressed only upon induction. Interleukin-1beta (IL-1beta) elevated Cox-2 mRNA steady state levels in a concentration-dependent manner, and kinetic studies showed that Cox-2 mRNA levels were already induced at the 2 h point and returned to the basal level after incubation for 24 h. The protein synthesis inhibitor, cycloheximide, induced Cox-2 mRNA expression and potentiated the effect of IL-1beta. Degradation of Cox-2 mRNA was inhibited by IL-1beta, which suggests regulation at the posttranscriptional level. IL-1beta also induced the expression of Cox-2 protein, as detected by immunofluorescence staining using Cox-2-specific polyclonal antibodies. Further, IL-1beta-induced synthesis of prostanoids was blocked by a Cox-2-specific inhibitor, NS-398. In addition, hCG induced Cox-2 mRNA expression and potentiated the effect of IL-1beta. However, in contrast to the rapid and transient effect of IL-1beta on Cox-2 mRNA, the effect of hCG followed slower kinetics. We have previously shown that hCG induces expression of human FP receptor mRNA in cultured human GL cells. We now show that IL-1beta induces FP receptor mRNA in a time- and concentration-dependent manner. Our data suggest that Cox-2 and FP receptor are coexpressed in freshly isolated human granulosa cells and that their expression is up-regulated by IL-1beta and hCG in cultured human GL cells.
authors.affiliation: Department of Obstetrics and Gynecology, University of Helsinki, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Narko
authors.forename: O
authors.initials: O
authors.lastname: Ritvos
authors.forename: A
authors.initials: A
authors.lastname: Ristimäki
mesh_terms: D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D051546:Cyclooxygenase 2; D004790:Enzyme Induction; D005260:Female; D006107:Granulosa Cells / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics*; D007700:Kinetics; D008184:Luteal Cells / Q000378:metabolism*; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D011982:Receptors, Prostaglandin / Q000235:genetics*
chemical_list: D006063:Chorionic Gonadotropin; D007375:Interleukin-1; D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D011982:Receptors, Prostaglandin; C034671:prostaglandin F2alpha receptor; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases