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: Yoko Ikoma, Seiji Nomura, Tomomi Ito, Yoshinari Katsumata, Masayuki Nakata, Kumi Iwanaga, Mayumi Okada, Fumitaka Kikkawa, Koji Tamakoshi, Tetsuo Nagasaka, Masafumi Tsujimoto, Shigehiko Mizutani
• Journal: Molecular human reproduction (Mol Hum Reprod) Vol. 9 Issue 2 Pg. 103-10 (Feb 2003) ISSN: 1360-9947 [Print] England
• PMID: 12569180 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Interleukin-1
• RNA, Messenger
• Receptors, Interleukin-1
• Recombinant Fusion Proteins
• Cycloheximide
• Luciferases
• Cystinyl Aminopeptidase
• leucyl-cystinyl aminopeptidase

Topics

• Choriocarcinoma
• Cycloheximide (pharmacology)
• Cystinyl Aminopeptidase (drug effects, genetics, metabolism)
• Female
• Gene Expression Regulation, Enzymologic (drug effects)
• Gene Expression Regulation, Neoplastic (drug effects)
• Genes, Reporter
• Humans
• Interleukin-1 (pharmacology)
• Luciferases (genetics)
• Pregnancy
• RNA, Messenger (genetics)
• Receptors, Interleukin-1 (genetics)
• Recombinant Fusion Proteins (genetics)
• Reverse Transcriptase Polymerase Chain Reaction
• Transcription, Genetic (drug effects)
• Transfection
• Tumor Cells, Cultured
• Uterine Neoplasms