title: The Role of Epithelial to Mesenchymal Transition in Human Amniotic Membrane Rupture.
abstract: Biochemical weakening of the amnion is a major factor preceding preterm premature rupture of membranes (PPROMs), leading to preterm birth. Activation of matrix metalloproteinases (MMPs) is known to play a key role in collagen degradation of the amnion; however, epithelial to mesenchymal transition (EMT) that is also induced by MMP activation has not been investigated as a mechanism for amnion weakening.
  
  
  
  To measure amniotic EMT associated with vaginal delivery (VD) compared with unlabored cesarean sections (CSs), and to assess changes in amniotic mechanical strength with pharmacologic inhibitors and inducers of EMT, thus testing the hypothesis that EMT is a key biochemical event that promotes amniotic rupture.
  
  
  
  (1) Amnions taken from VD contained a significantly increased number of mesenchymal cells relative to epithelial cells compared with unlabored CS by fluorescence-activated cell sorting analysis (60% vs 10%); (2) tumor necrosis factor (TNF)-α stimulation of amniotic epithelial cells increased expression of the mesenchymal marker vimentin after 2 days; (3) EMT inhibitor, etodolac, significantly increased the time and mechanical pressure required to rupture the amnion; and (4) TNF-α and another pharmacologic EMT inducer, ethacridine, decreased the time and mechanical pressure required for amnion rupture, further confirming that the mesenchymal phenotype significantly weakens the amnion.
  
  
  
  This work demonstrated amniotic cell EMT was associated with labor and EMT decreased the tensile strength of the amnion. These findings suggest a role for EMT in the pathophysiology of PPROM and may provide a basis for development of therapies to prevent preterm labor.
authors.affiliation: Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California 90095, Los Angeles, Los Angeles, California.
authors.forename: Carla
authors.initials: C
authors.lastname: Janzen
authors.affiliation: Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California 90095, Los Angeles, Los Angeles, California.
authors.forename: Suvajit
authors.initials: S
authors.lastname: Sen
authors.affiliation: Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California 90095, Los Angeles, Los Angeles, California.
authors.forename: Margarida Y Y
authors.initials: MY
authors.lastname: Lei
authors.affiliation: Faculty of Medical Sciences of Santa Casa de Sao Paulo, Sao Paulo, 01221-020, Brazil.
authors.forename: Marina
authors.initials: M
authors.lastname: Gagliardi de Assumpcao
authors.affiliation: University of Western Australia and Curtin University, Crawley, Western Australia 6009, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Challis
authors.affiliation: Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California 90095, Los Angeles, Los Angeles, California.
authors.forename: Gautam
authors.initials: G
authors.lastname: Chaudhuri
mesh_terms: D000650:Amnion / Q000187:drug effects* / Q000378:metabolism; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D017308:Etodolac / Q000494:pharmacology; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000378:metabolism*; D006801:Humans; D020782:Matrix Metalloproteinases / Q000378:metabolism; D011247:Pregnancy; D013718:Tensile Strength / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D014409:Tumor Necrosis Factor-alpha; D017308:Etodolac; D020782:Matrix Metalloproteinases