Placenta
Volume 31, Issue 10 , Pages 886-892, October 2010

Alpha-lipoic acid inhibits thrombin-induced fetal membrane weakening in vitro☆

  • R.M. Moore

      Affiliations

    • Departments of Pediatrics, Case Western Reserve University, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH, USA
    • ,
  • F. Schatz

      Affiliations

    • Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA
    • ,
  • D. Kumar

      Affiliations

    • Departments of Pediatrics, Case Western Reserve University, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH, USA
    • ,
  • B.M. Mercer

      Affiliations

    • Department of Reproductive Biology, Case Western Reserve University, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH, USA
    • ,
  • A. Abdelrahim

      Affiliations

    • Departments of Pediatrics, Case Western Reserve University, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH, USA
    • ,
  • N. Rangaswamy

      Affiliations

    • Departments of Pediatrics, Case Western Reserve University, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH, USA
    • ,
  • C. Bartel

      Affiliations

    • Departments of Pediatrics, Case Western Reserve University, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH, USA
    • ,
  • J.M. Mansour

      Affiliations

    • Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH, USA
    • ,
  • C.J. Lockwood

      Affiliations

    • Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA
    • ,
  • J.J. Moore

      Affiliations

    • Departments of Pediatrics, Case Western Reserve University, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH, USA
    • Department of Reproductive Biology, Case Western Reserve University, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH, USA
    • Corresponding Author InformationCorresponding author. Department of Pediatrics and Reproductive Biology, CWRU, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH 44109, USA. Tel.: +1 216 778 5909; fax: +1 216 778 3252.

Accepted 23 July 2010. published online 16 August 2010.

Abstract 

Cytokine-mediated inflammation and abruption-induced thrombin generation are separately implicated in matrix metalloproteinase (MMP)-mediated weakening of fetal membranes (FM) leading to preterm premature rupture of the fetal membranes (PPROM). At term, FM of both labored vaginal and unlabored Cesarean deliveries exhibit a weak zone overlying the cervix exhibiting ECM remodeling characterized by increased MMP9 protein and activity. We have reproduced these biochemical changes as well as FM weakening in vitro using tumor necrosis factor-alpha (TNF) and interleukin (IL)-1β, inflammatory cytokines implicated in PPROM. Additionally, we have reported that the antioxidant and NFκB inhibitor alpha-lipoic Acid (LA) blocks these TNF-induced effects. We now present the first direct evidence that thrombin also can induce FM weakening in vitro, and LA treatment inhibits this thrombin-induced-weakening. Full thickness FM fragments from unlabored Cesarean deliveries were incubated with increasing doses of thrombin (0–100 u/ml) for 48 h. Fragments were then strength tested (breaking force and work to rupture) using our published methodology. MMP3 and 9 levels in tissue extracts were determined by Western blot and densitometry. To determine the effect of LA, FM fragments were incubated with control medium or 10 u/ml thrombin, with or without 0.25 mM LA. Strength testing and MMP induction were determined. Thrombin induced a dose-dependent decrease in FM strength (42% baseline rupture force and 45% work to rupture) coupled with a dose-dependent increase in MMP3 and 9 expression (all p < 0.001). Treatment of FM with 0.25 mM LA completely inhibited thrombin-induced FM weakening and MMP expression (all p < 0.001). Thrombin treatment of cultured FM induces mechanical weakening and increased MMP3 and 9. Treatment of FM with LA inhibits these thrombin-induced effects. We speculate LA may prove clinically useful in prevention of PPROM associated with abruption.

Keywords: Fetal membranes, Biomechanics, Thrombin, Lipoic acid, MMP9, MMP3, Abruption

 

☆ Location where study was performed: MetroHealth Medical Center, Cleveland, Ohio. Presentation: Presented at the Annual Meeting of the SGI, Orlando Fl, March 25, 2010.

PII: S0143-4004(10)00281-X

doi:10.1016/j.placenta.2010.07.012

Placenta
Volume 31, Issue 10 , Pages 886-892, October 2010

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