| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 2788476 | Placenta | 2015 | 7 Pages |
•S1P activates IL-8 mRNA expression and secretion in trophoblast cell line.•S1PR1 is the main receptor regulating S1P dependent IL-8 gene expression.•S1P-induced IL-8 secretion is mainly regulated via S1PR2 receptor subtype.•Rho-GTPase dependent pathways regulate IL-8 protein secretion.
IntroductionBoth villous and extravillous trophoblast (EVT) cells produce a wide range of cytokines and also respond to them in autocrine and paracrine manner. Deregulation of cytokine secretion may lead to various pathologic conditions including preeclampsia. IL-8, a pro-inflammatory cytokine, regulates various cellular functions such as neutrophil trafficking, cell adhesion, tumor growth and has a role in placental development. IL-8 also promotes trophoblast cell migration and invasion, and stimulates the secretion of progesterone. The induction and mechanism of IL-8 secretion by EVT is still unknown.MethodsIL-8 mRNA expression and secretion was determined using real-time PCR and ELISA respectively. To identify the mechanism of IL-8 expression and secretion, selective antagonists and agonist of S1P receptor subtypes, Rac1 and Rho-kinase inhibitors were used.ResultsWe found that S1P induces IL-8 gene expression and protein secretion in EVT derived HTR-8/SVneo cells but not in BeWo cells. SEW2781, the selective agonist of S1PR1, induced IL-8 gene expression but not protein secretion. The specific S1PR2 inhibitor JTE-013 could drastically inhibit IL-8 secretion. Furthermore, pre-treatment of cells with the selective S1PR1/S1PR3 antagonist VPC23019 inhibited IL-8 secretion by ∼45%. Selective Rho-kinase inhibitor Y27632 and Rac1 inhibitor NSC23766 could block IL-8 secretion in these cells.DiscussionIn this study, we could show for the first time that S1P induces IL-8 mRNA expression and protein secretion in EVT cell line. S1P-induced IL-8 gene expression is mainly regulated via S1PR1 and its secretion is regulated through S1PR2 receptor subtype. Rho GTPases signaling is essential for S1P-induced IL-8 secretion.
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