title: Sphingosine 1-phosphate in amniotic fluid modulates cyclooxygenase-2 expression in human amnion-derived WISH cells.
abstract: The metabolism of arachidonic acid, in particular the generation of prostaglandins (PGs), has been proposed to play a key role in the regulation of labor. Moreover, several extracellular proteins have been reported to modulate PG synthesis in amnion cells. In this study, we found that lipid components dissolved in the amniotic fluid modulate PG synthesis in WISH human amnion cells and identified one of these components as a sphingosine 1-phosphate (S1P). WISH cells express several S1P receptors including S1P1, S1P2, and S1P3. When WISH cells were stimulated with S1P, PGE2 synthesis increased in a concentration-dependent manner, showing maximal activity at around 100 nM. S1P treatment also caused the up-regulation of cyclooxygenase-2 (COX-2) mRNA and protein, which was apparent within 3-12 h of stimulation. In terms of the intracellular signaling pathway of S1P-induced WISH cell activation, we found that S1P stimulated two kinds of MAPK, ERK, and p38 kinase. We examined the roles of these two MAPKs in S1P-induced COX-2 expression. S1P-induced COX-2 expression was blocked completely by PD-98059 but not by SB-203580, suggesting that ERK has a critical role in the process. Transfection of S1P1 or S1P3 but not of S1P2 antisense oligonucleotide inhibited S1P-induced COX-2 expression and PGE2 production in WISH cells, indicating the involvements of S1P1 and S1P3 in the processes. This study demonstrates the physiological role of S1P in amniotic fluid and its effect on the modulation of COX-2 expression and PGs synthesis in WISH cells.
authors.affiliation: Medical Research Center for Cancer Molecular Therapy and Department of Biochemistry, College of Medicine, Dong-A University, Busan 602-714, Korea.
authors.forename: Jung Im
authors.initials: JI
authors.lastname: Kim
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Jo
authors.forename: Ha-Young
authors.initials: HY
authors.lastname: Lee
authors.forename: Moon Seok
authors.initials: MS
authors.lastname: Cha
authors.forename: Jung Kee
authors.initials: JK
authors.lastname: Min
authors.forename: Chang Hwan
authors.initials: CH
authors.lastname: Choi
authors.forename: Yong Moon
authors.initials: YM
authors.lastname: Lee
authors.forename: Young-Ae
authors.initials: YA
authors.lastname: Choi
authors.forename: Suk-Hwan
authors.initials: SH
authors.lastname: Baek
authors.forename: Sung Ho
authors.initials: SH
authors.lastname: Ryu
authors.forename: Kyu Sup
authors.initials: KS
authors.lastname: Lee
authors.forename: Jong-Young
authors.initials: JY
authors.lastname: Kwak
authors.forename: Yoe-Sik
authors.initials: YS
authors.lastname: Bae
mesh_terms: D000650:Amnion / Q000166:cytology / Q000201:enzymology*; D000653:Amniotic Fluid / Q000378:metabolism*; D001483:Base Sequence; D015153:Blotting, Western; D002460:Cell Line; D051546:Cyclooxygenase 2; D017931:DNA Primers; D015232:Dinoprostone / Q000096:biosynthesis; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D008246:Lysophospholipids; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D007527:Isoenzymes; D008246:Lysophospholipids; D008565:Membrane Proteins; C060506:sphingosine 1-phosphate; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone; D013110:Sphingosine