title: Matrix metalloproteinase-8 is expressed in human chorion during labor.
abstract: OBJECTIVE
  The purpose of this study was to investigate the expression of matrix metalloproteinase-8 by human fetal membranes during labor.
  
  
  METHODS
  Fetal membranes were obtained from women who underwent normal labor or elective cesarean delivery at term. Matrix metalloproteinase-8 levels in fetal membranes were determined by enzyme-linked immunosorbent assay and Western blot; the expression of the matrix metalloproteinase-8 gene was detected by reverse transcription-polymerase chain reaction. Immunohistochemistry and in situ hybridization was performed to localize matrix metalloproteinase-8 protein and messenger RNA in intact membranes.
  
  
  RESULTS
  Matrix metalloproteinase-8 protein levels were increased 5-fold in fetal membranes from labor compared with membranes that were obtained from cesarean delivery. Western blots confirmed the presence of matrix metalloproteinase-8 in protein extracts. Reverse transcription-polymerase chain reaction, in situ hybridization, and immunohistochemistry demonstrated that matrix metalloproteinase-8 messenger RNA and protein were expressed almost exclusively in the chorion after labor.
  
  
  CONCLUSIONS
  We conclude that matrix metalloproteinase-8 is produced primarily by chorionic cells in human fetal membranes and that the level of matrix metalloproteinase-8 protein and messenger RNA expression in fetal membranes increases during labor.
authors.affiliation: Research Unit in Reproductive Medicine, Hospital de Ginecobstetricia Luis Castelazo Ayala, Instituto Mexicano del Seguro Social, Mexico City, Mexico.
authors.forename: Fabián
authors.initials: F
authors.lastname: Arechavaleta-Velasco
authors.forename: Dominic
authors.initials: D
authors.lastname: Marciano
authors.forename: Laura
authors.initials: L
authors.lastname: Díaz-Cueto
authors.forename: Samuel
authors.initials: S
authors.lastname: Parry
mesh_terms: D015153:Blotting, Western; D016022:Case-Control Studies; D002823:Chorion / Q000201:enzymology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007743:Labor, Obstetric / Q000378:metabolism*; D020784:Matrix Metalloproteinase 8 / Q000235:genetics / Q000378:metabolism*; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D012333:RNA, Messenger; D020784:Matrix Metalloproteinase 8