title: Interleukin-1beta stimulates placental leucine aminopeptidase/oxytocinase expression in BeWo choriocarcinoma cells.
abstract: In addition to prostaglandins, inflammatory cytokines induce uterine contraction via oxytocin (OT). Placental leucine aminopeptidase (P-LAP), an oxytocinase that is identical to cystine aminopeptidase, destroys OT activity. Patients with spontaneous preterm delivery have higher concentrations of inflammatory cytokines and lower P-LAP activities than those with normal delivery. In addition, the P-LAP promoter region contains putative binding sites for cytokine-induced transcription factors. We therefore postulated that inflammatory cytokines suppress P-LAP expression and examined this notion using BeWo choriocarcinoma cells cultured in the presence of cytokines. However, interleukin-1beta (IL-1beta) increased P-LAP activity in a time- and dose-dependent manner. Furthermore, Western blot analysis showed a dose-dependent increase of P-LAP proteins. We also detected IL-1 type I receptor mRNA in BeWo cells by RT-PCR. Semi-quantitative RT-PCR and Southern blot analysis showed that IL-1beta also increased P-LAP mRNA, which was abrogated by prior exposure to cycloheximide. Luciferase assays did not reveal any regulatory regions that could explain IL-1beta-induced P-LAP mRNA accumulation within 1.1 kb upstream of the P-LAP gene. Immunohistochemical analysis of human placenta with chorioamnionitis demonstrated prominent P-LAP staining at sites of abundant inflammatory cell infiltration. These findings indicated that prolonged exposure to IL-1beta induces P-LAP in the trophoblasts, possibly via other de-novo protein synthesis, which contradicted our initial hypothesis.
authors.affiliation: Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ikoma
authors.forename: Seiji
authors.initials: S
authors.lastname: Nomura
authors.forename: Tomomi
authors.initials: T
authors.lastname: Ito
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Katsumata
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nakata
authors.forename: Kumi
authors.initials: K
authors.lastname: Iwanaga
authors.forename: Mayumi
authors.initials: M
authors.lastname: Okada
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Kikkawa
authors.forename: Koji
authors.initials: K
authors.lastname: Tamakoshi
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Nagasaka
authors.forename: Masafumi
authors.initials: M
authors.lastname: Tsujimoto
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Mizutani
mesh_terms: D002822:Choriocarcinoma; D003513:Cycloheximide / Q000494:pharmacology; D010122:Cystinyl Aminopeptidase / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D017930:Genes, Reporter; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D008156:Luciferases / Q000235:genetics; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics; D017472:Receptors, Interleukin-1 / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D014407:Tumor Cells, Cultured; D014594:Uterine Neoplasms
chemical_list: D007375:Interleukin-1; D012333:RNA, Messenger; D017472:Receptors, Interleukin-1; D011993:Recombinant Fusion Proteins; D003513:Cycloheximide; D008156:Luciferases; D010122:Cystinyl Aminopeptidase; C105964:leucyl-cystinyl aminopeptidase