title: Pentoxifylline attenuates HPV-16 associated necrosis in placental trophoblasts.
abstract: OBJECTIVE
  Human papillomaviruses (HPV) have been associated with placental inflammation resulting in high-risk preterm birth. The premise for this study was that treatment with anti-inflammatory pentoxifylline would inhibit HPV-mediated placental cell death. The objectives were: (1) to study the effects of HPV-16 exposure on trophoblast cells and (2) to evaluate pentoxifylline in preventing the damaging effects of HPV-16.
  
  
  METHODS
  Mouse embryos (1-cell) were cultured (G1plus medium, 72 h, 37 °C, 5 % CO2 in air), divided into four groups at blastocyst-stage and incubated to implantation stage. Implanted trophoblasts were exposed to either HPV-16 (group 1), concomitant HPV-16 and 3 mM pentoxifylline (group 2), 3 mM pentoxifylline only (group 3) or control medium (group 4) and further incubated for 24 h. HPV-16 were from SiHa cell lysates. Trophoblast structural integrity was assessed by morphometric analysis while apoptosis and necrosis were detected using dual-stain fluorescence assay.
  
  
  RESULTS
  Trophoblast outgrowth was reduced by 90% (P < 0.05) in HPV-16 presence (629 ± 265 µ(2), mean + SEM) when compared with controls (6,456 ± 795 µ(2)). Pentoxifylline attenuated the effects of HPV-16 (4,308 ± 362 µ(2)). Nuclear size of HPV-16 infected trophoblasts was smallest among the groups (P < 0.005). HPV-16 decreased cell viability and increased necrosis but not apoptosis. Pentoxifylline prevented HPV-16 associated necrosis in trophoblasts.
  
  
  CONCLUSIONS
  HPV-16 decreased nuclear size and trophoblast outgrowth but these effects were attenuated by the phosphodiesterase inhibitor, pentoxifylline. The action of HPV-16 on trophoblasts was increased cell necrosis suggesting that HPV-16 pathogenesis involved either cAMP inhibition and/or activated TNF pathways.
authors.affiliation: Department of Gynecology and Obstetrics, Loma Linda University School of Medicine, 11370 Anderson St., Suite 3950, Loma Linda, CA, 92354, USA.
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Chen
authors.forename: Barry S
authors.initials: BS
authors.lastname: Block
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Chan
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001755:Blastocyst; D002470:Cell Survival / Q000187:drug effects*; D010064:Embryo Implantation / Q000187:drug effects*; D005260:Female; D052162:Human papillomavirus 16 / Q000502:physiology*; D006801:Humans; D051379:Mice; D009336:Necrosis; D027383:Papillomaviridae; D010431:Pentoxifylline / Q000494:pharmacology*; D010726:Phosphodiesterase Inhibitors; D010920:Placenta / Q000378:metabolism / Q000473:pathology*; D011247:Pregnancy; D014327:Trophoblasts / Q000378:metabolism / Q000473:pathology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D010726:Phosphodiesterase Inhibitors; D014409:Tumor Necrosis Factor-alpha; D010431:Pentoxifylline