title: Chorioamniotic membrane senescence: a signal for parturition?
abstract: OBJECTIVE
  Senescence is an important biological phenomenon involved in both physiologic and pathologic processes. We propose that chorioamniotic membrane senescence is a mechanism associated with human parturition. The present study was conducted to explore the association between senescence and normal term parturition by examining the morphologic and biochemical evidences in chorioamniotic membranes.
  
  
  METHODS
  Chorioamniotic membranes were collected from normal term deliveries; group 1: term labor and group 2: term, not in labor. Senescence-related morphologic changes were determined by transmission electron microscopy and biochemical changes were studied by senescence-associated (SA) β-galactosidase staining. Amniotic fluid samples collected from both term labor and term not in labor were analyzed for 14 SA secretory phenotype (SASP) markers.
  
  
  RESULTS
  Morphologic evidence of cellular senescence (enlarged cells and organelles) and a higher number of SA β-galactosidase-stained amnion and chorion cells were observed in chorioamniotic membranes obtained from women in labor at term, when compared to term not in labor. The concentration of proinflammatory SASP markers (granulocyte macrophage colony-stimulating factor, interleukin-6 and -8) was significantly higher in the amniotic fluid of women in labor at term than women not in labor. In contrast, SASP factors that protect against cell death (eotaxin-1, soluble Fas ligand, osteoprotegerin, and intercellular adhesion molecule-1) were significantly lower in the amniotic fluid samples from term labor.
  
  
  CONCLUSIONS
  Morphologic and biochemical features of senescence were more frequent in chorioamniotic membranes from women who experienced term labor. Senescence of chorioamniotic membranes were also associated with amniotic fluid SASP markers.
authors.affiliation: Division of Maternal-Fetal Medicine and Perinatal Research, Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX.
authors.forename: Faranak
authors.initials: F
authors.lastname: Behnia
authors.affiliation: Department of Epidemiology and Biostatistics, Texas A&M University Health Science Center, College Station, TX.
authors.forename: Brandie D
authors.initials: BD
authors.lastname: Taylor
authors.affiliation: Electron Microscopy Core Laboratory, University of Texas Medical Branch, Galveston, TX.
authors.forename: Michael
authors.initials: M
authors.lastname: Woodson
authors.affiliation: Department of Obstetrics and Gynecology, Charles University, Hradec Kralove, Czech Republic.
authors.forename: Marian
authors.initials: M
authors.lastname: Kacerovsky
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, TX.
authors.forename: Hal
authors.initials: H
authors.lastname: Hawkins
authors.affiliation: Perinatal Research Center, Nashville, TN.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Fortunato
authors.affiliation: Division of Maternal-Fetal Medicine and Perinatal Research, Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX.
authors.forename: George R
authors.initials: GR
authors.lastname: Saade
authors.affiliation: Division of Maternal-Fetal Medicine and Perinatal Research, Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX. Electronic address: ra2menon@utmb.edu.
authors.forename: Ramkumar
authors.initials: R
authors.lastname: Menon
mesh_terms: D000328:Adult; D000650:Amnion / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D000653:Amniotic Fluid / Q000166:cytology / Q000378:metabolism*; D016022:Case-Control Studies; D016922:Cellular Senescence; D054413:Chemokine CCL11 / Q000378:metabolism; D002823:Chorion / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D003430:Cross-Sectional Studies; D053222:Fas Ligand Protein / Q000378:metabolism; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D007743:Labor, Obstetric / Q000378:metabolism*; D008928:Mitochondria / Q000648:ultrastructure; D053244:Osteoprotegerin / Q000378:metabolism; D011247:Pregnancy; D047929:Term Birth / Q000378:metabolism*; D055815:Young Adult; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: C515456:CCL11 protein, human; C508606:CXCL8 protein, human; D054413:Chemokine CCL11; D053222:Fas Ligand Protein; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D053244:Osteoprotegerin; C506030:TNFRSF11B protein, human; D018799:Intercellular Adhesion Molecule-1; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D001616:beta-Galactosidase
keywords: aging; delivery; fetal signals; labor; pregnancy; premature birth; senescence-associated secretory phenotype; sterile inflammation; β-galactosidase