title: A role for lipoxin A₄ as an anti-inflammatory mediator in the human endometrium.
abstract: Lipoxin A(4) is a lipid mediator that elicits anti-inflammatory and pro-resolution actions via its receptor, formyl peptide receptor 2 (FPR2/ALX). In this study, we aimed to investigate the expression and potential role of lipoxin A(4) and FPR2/ALX in the regulation of inflammation associated with cyclical remodeling of the human endometrium across the menstrual cycle and during early pregnancy. Using quantitative RT-PCR analysis, we found that FPR2/ALX expression is upregulated during the menstrual phase of the cycle and in decidua tissue from the first trimester of pregnancy. We localized the site of expression of FPR2/ALX in menstrual phase endometrium and first-trimester decidua tissue to glandular epithelial cells and cells within the stromal compartment, including cells lining the blood vessels and immune cells. Measurement of serum lipoxin A(4) by ELISA revealed no difference in its levels across the menstrual cycle but an elevation in early pregnancy (P<0.001). We found that lipoxin A(4) was regulated by human chorionic gonadotrophin (hCG) during early pregnancy, because treatment of human decidua tissue with hCG increased lipoxin A(4) release (P<0.01). Finally, we have shown that lipoxin A(4) can suppress phorbol myristate acetate-induced expression of the inflammatory cytokines interleukin 6 and 8 in human endometrium and decidua tissue. These results demonstrate for the first time that lipoxin A(4) and its receptor FPR2/ALX can regulate inflammatory events in the human endometrium and decidua of early pregnancy.
authors.affiliation: MRC Human Reproductive Sciences Unit, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK.
authors.forename: Linsay J
authors.initials: LJ
authors.lastname: Macdonald
authors.forename: Sheila C
authors.initials: SC
authors.lastname: Boddy
authors.forename: Fiona C
authors.initials: FC
authors.lastname: Denison
authors.forename: Kurt J
authors.initials: KJ
authors.lastname: Sales
authors.forename: Henry N
authors.initials: HN
authors.lastname: Jabbour
mesh_terms: D000328:Adult; D006063:Chorionic Gonadotropin / Q000378:metabolism; D003656:Decidua / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D004717:Endometrium / Q000166:cytology / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors* / Q000378:metabolism; D007378:Interleukins / Q000235:genetics / Q000378:metabolism; D044045:Lipoxins / Q000097:blood / Q000378:metabolism*; D008597:Menstrual Cycle / Q000097:blood / Q000378:metabolism*; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D044042:Receptors, Formyl Peptide / Q000235:genetics / Q000378:metabolism; D044067:Receptors, Lipoxin / Q000235:genetics / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000037:antagonists & inhibitors / Q000633:toxicity; D046509:Tissue Culture Techniques; D055815:Young Adult
chemical_list: D006063:Chorionic Gonadotropin; C105101:FPR2 protein, human; D018836:Inflammation Mediators; D007378:Interleukins; D044045:Lipoxins; D012333:RNA, Messenger; D044042:Receptors, Formyl Peptide; D044067:Receptors, Lipoxin; C040527:lipoxin A4; D013755:Tetradecanoylphorbol Acetate