Retinoids regulate human amniotic tissue-type plasminogen activator gene by a two-step mechanism

J Cell Mol Med. 2010 Jun;14(6B):1793-805. doi: 10.1111/j.1582-4934.2009.00802.x. Epub 2009 Jun 16.

Abstract

The collagenolytic effects of the tissue-type plasminogen activator (t-PA) leading to extracellular matrix degradation are clearly involved in the physiopathology of human foetal membranes rupture. Nevertheless, the regulation of t-PA gene expression in extraembryonic developmental contexts remains unknown. The aim of our study is to propose the retinoic acids (RAs) as molecular regulators of t-PA expression in foetal membranes. RA induced t-PA mRNA and proteins in a time-dependent manner in amniotic membrane explants and Wistar Institute Susan Hayflick (WISH) cells. Furthermore, the use of cycloheximide revealed a two-step regulation of t-PA gene. Gene reporter assays confirmed that the RA-induced t-PA gene expression occurred through interactions of retinoid receptors (RARs and RXRs) with a DR5 response element located at -7 kb from the transcription site. Site-directed mutagenesis of this region of the t-PA promoter showed that SP1 factor was also retinoid-mediated induction, and immunoprecipitation assays revealed that SP1 and RAR/RXR interacted physically. Chromatin immunoprecipitation demonstrated that interactions between RARs, RXRs and t-PA promoter were time dependent: RAR-alpha/RXR-alpha bound DR5 motif before and up to 12 hrs of RA exposure, and RAR-beta/RXR-alpha bound DR5 response element after 12 hrs of RA treatment. Finally, experiments using shRNA and RAR-beta-specific antagonist revealed that reducing RAR-beta induction decreased t-PA induction. Altogether, our results established that the RA-mediated regulation of t-PA in human foetal membranes occurred through two steps, with a major role played by RAR-beta.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amnion / drug effects*
  • Amnion / metabolism*
  • Cell Line
  • Dibenzazepines / pharmacology
  • Gene Expression Regulation / drug effects*
  • Humans
  • Protein Binding / drug effects
  • RNA, Small Interfering / metabolism
  • Receptors, Retinoic Acid / antagonists & inhibitors
  • Receptors, Retinoic Acid / genetics
  • Receptors, Retinoic Acid / metabolism
  • Response Elements / genetics
  • Retinoid X Receptors / metabolism
  • Retinoids / pharmacology*
  • Sp1 Transcription Factor / metabolism
  • Tissue Plasminogen Activator / genetics*
  • Tissue Plasminogen Activator / metabolism
  • Transcriptional Activation / drug effects
  • Transcriptional Activation / genetics

Substances

  • Dibenzazepines
  • LE 135
  • RNA, Small Interfering
  • Receptors, Retinoic Acid
  • Retinoid X Receptors
  • Retinoids
  • Sp1 Transcription Factor
  • retinoic acid receptor beta
  • Tissue Plasminogen Activator