title: Prostaglandin (PG) F(2alpha) receptor expression and signaling in human endometrium: role of PGF(2alpha) in epithelial cell proliferation.
abstract: Prostaglandin (PG) F(2alpha), a member of the prostanoid bioactive lipid family, is secreted by human endometrium throughout the menstrual cycle and is present in both menstrual fluid and medium of endometrial explants in culture. PGF(2alpha) mediates its effects through a seven-transmembrane G-protein-coupled receptor (FP). The aim of this study was to examine the temporal expression, signaling, and role of FP receptor in the human endometrium. Quantitative RT-PCR analysis demonstrated highest expression of FP receptor in the mid- to late-proliferative phase, compared with early-proliferative and secretory phase endometrium. In situ hybridization studies localized FP receptor mRNA expression to the epithelial cell compartment during the mid- to late-proliferative phase. Moreover, treatment of endometrial tissue with 1-100 nM PGF(2alpha) induced a concentration-dependent increase in inositol phosphate mobilization, indicating functional FP receptor expression. The Ishikawa human endometrial epithelial cell line was used to investigate further the signaling and role of PGF(2alpha) in endometrial epithelial cells. Ishikawa cells endogenously express the FP receptor, and treatment with 1-100 nM PGF(2alpha) elicits a concentration-dependent increase in inositol phosphate release. Moreover, treatment of Ishikawa cells with 100 nM PGF(2alpha) induced phosphorylation of ERK1/2 that was abolished when cells were cotreated with 50 micro M PD98059 (MAPK kinase inhibitor) or 10 micro M U73122 [phospholipase C (PLC) inhibitor]. Treatment of Ishikawa cells with PGF(2alpha) for 24 h induced a significant concentration-dependent increase in Ishikawa cell proliferation. Coincubation of the cells with 50 micro M PD98059 or 2 micro M U73122 demonstrated that PLC inhibition significantly reduced PGF(2alpha)-induced proliferation, whereas MAPK kinase inhibition had no effect. In summary, these studies demonstrate increased FP receptor expression in endometrial epithelial cells during the proliferative phase of the menstrual cycle and identify a role for PGF(2alpha) in epithelial cell proliferation via a PLC-dependent pathway.
authors.affiliation: Medical Research Council Human Reproductive Sciences Unit, Centre for Reproductive Biology, Edinburgh EH16 4SB, United Kingdom.
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Milne
authors.forename: Henry N
authors.initials: HN
authors.lastname: Jabbour
mesh_terms: D002455:Cell Division; D002460:Cell Line; D002478:Cells, Cultured; D015237:Dinoprost / Q000494:pharmacology / Q000502:physiology*; D004717:Endometrium / Q000166:cytology* / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000737:chemistry; D004963:Estrenes / Q000494:pharmacology; D005260:Female; D005419:Flavonoids / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000502:physiology; D015870:Gene Expression; D006801:Humans; D017403:In Situ Hybridization; D008597:Menstrual Cycle; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010766:Phosphorylation; D011760:Pyrrolidinones / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D011982:Receptors, Prostaglandin / Q000235:genetics* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors
chemical_list: D004791:Enzyme Inhibitors; D004963:Estrenes; D005419:Flavonoids; D011760:Pyrrolidinones; D012333:RNA, Messenger; D011982:Receptors, Prostaglandin; C034671:prostaglandin F2alpha receptor; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D015237:Dinoprost; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one