title: Prostaglandin synthesis by the porcine corpus luteum: effect of tumor necrosis factor-α.
abstract: The porcine corpus luteum (CL) displays delayed sensitivity to PGF-2α (luteolytic sensitivity, [LS]) until days 12 to 13 of cycle. The control of LS is unknown, but it is temporally associated with macrophage (which secrete tumor necrosis factor-α; TNF-α) infiltration into the CL. Other studies showed that TNF-α induces LS in vitro and that prostaglandins (PGs) may be involved in this mechanism. In experiment 1, PGF-2α and PGE secretion by luteal cells (LCs) was measured on days 4 to 14 of the estrous cycle, and the expression of PTGFS/AKR1B1 and PTGES/mPGES-1, determined by Western blot, before (day 7) vs after (day 13) the onset of LS. Results showed that the PGF-2α:PGE ratio increased significantly (P < 0.05) from day 4 to 13-14, and PTGFS/AKR1B1 and PTGES/mPGES-1 were significantly increased (P < 0.05) on day 13 (vs day 7). In experiment 2, LCs were collected from porcine CL at early (∼days 4-6) or mid (∼days 7-12) stages of the estrous cycle and cultured with 0, 0.1, 1, or 10 ng/mL TNF-α. Results showed that TNF-α significantly increased (P < 0.05) messenger RNA (mRNA) expression of cyclooxygenase (COX)-2 and mPGES-1 but not AKR1B1. TNF-α had no significant effects on AKR1B1 or mPGES protein abundance. TNF-α significantly increased (P < 0.05) PGE-2 but had no effect on PGF-2α secretion or on the PGF-2α:PGE2 ratio. In conclusion, although TNF-α increased COX2 and mPGES-1 mRNA, and PGE-2 secretion in vitro, it did not increase the PGF-2α:PGE2 ratio. Studies are currently directed toward exploring other pathways (eg, FP receptor signaling) by which TNF-α induces LS in the porcine CL.
authors.affiliation: Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
authors.forename: J
authors.initials: J
authors.lastname: Chang
authors.affiliation: Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
authors.forename: S
authors.initials: S
authors.lastname: Frandsen
authors.affiliation: Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA. Electronic address: john_gadsby@ncsu.edu.
authors.forename: J E
authors.initials: JE
authors.lastname: Gadsby
mesh_terms: D000449:Aldehyde Reductase / Q000032:analysis / Q000235:genetics; D000818:Animals; D002478:Cells, Cultured; D003338:Corpus Luteum / Q000187:drug effects / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000235:genetics; D015237:Dinoprost / Q000032:analysis / Q000096:biosynthesis / Q000494:pharmacology; D015232:Dinoprostone / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism; D005260:Female; D008184:Luteal Cells / Q000378:metabolism; D003341:Luteolysis / Q000187:drug effects; D000071876:Prostaglandin-E Synthases / Q000032:analysis / Q000235:genetics; D011453:Prostaglandins / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis; D034421:Sus scrofa / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D011453:Prostaglandins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D015237:Dinoprost; D000449:Aldehyde Reductase; D051546:Cyclooxygenase 2; D000071876:Prostaglandin-E Synthases; D015232:Dinoprostone
keywords: Corpus luteum; Luteolytic sensitivity; Macrophage; Pig; Prostaglandin; Tumor necrosis factor-α