title: Urinary trypsin inhibitor down-regulates hyaluronic acid fragment-induced prostanoid release in cultured human amnion cells by inhibiting cyclo-oxygenase-2 expression.
abstract: We postulated that urinary trypsin inhibitor (UTI), a Kunitz-type protease inhibitor, may inhibit low molecular weight hyaluronic acid (HA) fragment-induced prostanoid release and de-novo expression of the inducible cyclo-oxygenase-2 (COX-2) isoform in human term amnion cells. Purified amnion cultures were obtained from human fetal membranes and were exposed to a HA fragment (molecular weight 35 kDa) in the presence or absence of UTI (0-5.0 micromol/l). Amnion cells treated with the HA fragment (100 nmol/l) released significantly more prostanoids (PGE2 and PGF2alpha) than controls (PGE2: 2.1 +/- 0.13 pg/10(6) cells/24 h compared with 0.42 +/- 0.01, P < 0.05; PGF2alpha: 1.0 +/- 0.17 pg/10(6) cells/24 h compared with 0.13 +/- 0.01, P < 0.05). UTI inhibited HA fragment-induced prostanoid release in a dose-dependent manner, with 50% inhibitory concentration values of 0.8 micromol/l for PGE2 and 1.9 micromol/l for PGF2alpha. Western blot analyses demonstrated that protein levels of COX-2 were substantially increased in amnion cells treated with HA fragment. HA fragment-mediated COX-2 production was markedly diminished by pretreatment with UTI (1.0 micromol/l). These results are the first to demonstrate that UTI is a potent inhibitor of HA fragment-induced arachidonic acid metabolism.
authors.affiliation: Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, Handacho 3600, Hamamatsu, Shizuoka, 431-3192, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kobayashi
authors.forename: G W
authors.initials: GW
authors.lastname: Sun
authors.forename: T
authors.initials: T
authors.lastname: Terao
mesh_terms: D000650:Amnion / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D002478:Cells, Cultured; D002585:Cesarean Section; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D015237:Dinoprost / Q000378:metabolism*; D015232:Dinoprostone / Q000378:metabolism*; D005260:Female; D006023:Glycoproteins / Q000494:pharmacology*; D006801:Humans; D006820:Hyaluronic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*; D007527:Isoenzymes / Q000378:metabolism*; D008565:Membrane Proteins; D011247:Pregnancy; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D014361:Trypsin Inhibitors / Q000494:pharmacology*
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D006023:Glycoproteins; D007527:Isoenzymes; D008565:Membrane Proteins; D014361:Trypsin Inhibitors; D006820:Hyaluronic Acid; D015237:Dinoprost; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone; C028665:urinastatin