title: Thrombin-dependent regulation of matrix metalloproteinase (MMP)-9 levels in human fetal membranes.
abstract: OBJECTIVE
  Amniochorion matrix metalloproteinase (MMP)-9 levels increase during labor, reaching a maximum in patients with preterm premature rupture of membranes (PPROM). Bleeding is a major risk factor for PPROM. Since such hemorrhage into the tissue factor-enriched decidua induces intense thrombin formation, we determined whether thrombin stimulates MMP levels in amniochorionic membranes.
  
  
  METHODS
  Fetal membrane (amniochorion) cultures were maintained in media with and without thrombin, lipopolysaccharide (LPS), thrombin receptor agonist peptide (TRAP)-14, and the anti-inflammatory steroid, dexamethasone (DEX). Concentrations of MMP-9, MMP-1, and tissue inhibitor of metalloproteinase (TIMP)-1 in culture media were measured by ELISA and normalized to total cell protein.
  
  
  RESULTS
  The presence of thrombin induced MMP-9 levels. TRAP-14, a thrombin receptor agonist, also significantly increased MMP-9 levels, suggesting that thrombin-induced changes in MMP-9 expression were mediated through the thrombin receptor. Conversely, levels of MMP-1 and TIMP-1 were not affected by thrombin treatment, indicative of specificity of its action. The presence of LPS increased the concentration of MMP-9 and MMP-1. In contrast, DEX treatment significantly reduced MMP-9 levels.
  
  
  CONCLUSIONS
  Our findings clearly demonstrated that thrombin treatment selectively increased the concentration of MMP-9 in culture media of amniochorionic membranes. Our results provide a potential mechanism through which alterations in hemostasis promote PPROM through thrombin-dependent stimulation of MMP-9.
authors.affiliation: Carolinas Medical Center, Charlotte, North Carolina, USA.
authors.forename: Courtney D
authors.initials: CD
authors.lastname: Stephenson
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Lockwood
authors.forename: Yuehong
authors.initials: Y
authors.lastname: Ma
authors.forename: Seth
authors.initials: S
authors.lastname: Guller
mesh_terms: D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D003907:Dexamethasone / Q000494:pharmacology*; D005321:Extraembryonic Membranes; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000378:metabolism; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000187:drug effects / Q000378:metabolism*; D009924:Organ Culture Techniques; D010446:Peptide Fragments / Q000494:pharmacology; D011247:Pregnancy; D013917:Thrombin / Q000502:physiology*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D008070:Lipopolysaccharides; D010446:Peptide Fragments; D019715:Tissue Inhibitor of Metalloproteinase-1; C072032:thrombin receptor peptide (42-55); D003907:Dexamethasone; D013917:Thrombin; D020780:Matrix Metalloproteinase 9; D020781:Matrix Metalloproteinase 1