title: Cyclic stretch augments production of neutrophil chemokines and matrix metalloproteinase-1 in human uterine smooth muscle cells.
abstract: OBJECTIVE
  The aim of this study was to investigate the impact of uterine contraction on the immune environment within the uterus during parturition.
  
  
  METHODS
  Uterine smooth muscle cells (USMC) were isolated from uterine myometrial tissues and cultured. The effects of cyclic stretch on mRNA and/or protein expression of IL-8, Groα, and pro-MMP-1 by USMC were measured using RT-PCR and ELISA. Neutrophil chemotactic activity in conditioned media was evaluated using migration assays. To evaluate the effect of progesterone (P(4) ), USMC were pretreated with P(4)  for 24 hr.
  
  
  RESULTS
  Cyclic stretch increased IL-8 and Groα mRNA and protein and pro-MMP-1 production significantly. Supernatants from stretched cells induced neutrophil chemotactic activity significantly; these effects were abrogated by anti-IL-8 or Groα neutralizing antibodies. Stretch effects were reduced by P(4) .
  
  
  CONCLUSIONS
  These results suggest that uterine contraction may induce neutrophil infiltration and MMP-1 production, which may contribute to cervical ripening and rupture of membrane. The inhibitory effects of P(4)  may explain the mechanism by which progestin prevents preterm labor.
authors.affiliation: Departmaent of Obstetrics and Gynecology, The University of Tokyo, Tokyo, Japan.
authors.forename: Yin
authors.initials: Y
authors.lastname: Zhao
authors.forename: Kaori
authors.initials: K
authors.lastname: Koga
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Osuga
authors.forename: Gentaro
authors.initials: G
authors.lastname: Izumi
authors.forename: Masashi
authors.initials: M
authors.lastname: Takamura
authors.forename: Miyuki
authors.initials: M
authors.lastname: Harada
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hirata
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Hirota
authors.forename: Osamu
authors.initials: O
authors.lastname: Yoshino
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Fujii
authors.forename: Shiro
authors.initials: S
authors.lastname: Kozuma
mesh_terms: D000328:Adult; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D060833:Cellular Microenvironment / Q000187:drug effects / Q000276:immunology; D054360:Chemokine CXCL1 / Q000235:genetics / Q000378:metabolism; D005260:Female; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D007743:Labor, Obstetric / Q000276:immunology*; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism*; D040542:Mechanotransduction, Cellular / Q000276:immunology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000201:enzymology / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology*; D011247:Pregnancy; D011374:Progesterone / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D014590:Uterine Contraction / Q000276:immunology*; D014599:Uterus / Q000276:immunology*
chemical_list: D054360:Chemokine CXCL1; D016209:Interleukin-8; D012333:RNA, Messenger; D011374:Progesterone; D020781:Matrix Metalloproteinase 1