title: Elafin in human endometrium: an antiprotease and antimicrobial molecule expressed during menstruation.
abstract: Elafin is an antiproteinase and antimicrobial molecule that is expressed at epithelial sites (for example, cervix). This study details the expression and regulation of elafin in the human endometrium. Elafin mRNA and protein expression were examined in endometrium throughout the menstrual cycle and in first-trimester decidua. Real-time quantitative PCR showed that expression of elafin mRNA peaked during menstruation. Elafin protein was localized to leukocytes scattered in the endometrial stroma during the late secretory and menstrual phases. Faint immunostaining was also present in glandular epithelium at these cycle stages. Immunofluorescent colocalization of elafin with neutrophil elastase confirmed that elafin was expressed by endometrial neutrophils around the time of menstruation. This is consistent with the expression profile observed from immunohistochemical studies. Primary endometrial epithelial cells were treated with proinflammatory molecules, and elafin mRNA was studied. A combination of the proinflammatory mediators, IL-1 beta and TNFalpha, increased elafin mRNA levels by 4.6-fold. These results show that endometrium expresses elafin in a menstruation-dependent manner. This is attributable to the presence of infiltrating leukocytes and increased inflammatory signaling. Elafin will regulate proteolytic enzymes during menstruation and will contribute to the innate defense against uterine infection.
authors.affiliation: Medical Research Council Human Reproductive Sciences Unit, University of Edinburgh, Centre for Reproductive Biology, Edinburgh, United Kingdom EH16 4SB. a.king@hrsu.mrc.ac.uk
authors.forename: Anne E
authors.initials: AE
authors.lastname: King
authors.forename: Hilary O D
authors.initials: HO
authors.lastname: Critchley
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Sallenave
authors.forename: Rodney W
authors.initials: RW
authors.lastname: Kelly
mesh_terms: D000328:Adult; D000890:Anti-Infective Agents / Q000378:metabolism*; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology; D003656:Decidua / Q000378:metabolism; D004717:Endometrium / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007150:Immunohistochemistry; D019272:Leukocyte Elastase / Q000378:metabolism; D008598:Menstruation / Q000378:metabolism*; D011247:Pregnancy; D011480:Protease Inhibitors / Q000378:metabolism*; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000890:Anti-Infective Agents; D016207:Cytokines; D011480:Protease Inhibitors; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; D012333:RNA, Messenger; D019272:Leukocyte Elastase