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

Area of Science:

• Reproductive biology
• Molecular endocrinology
• Extracellular matrix dynamics

Background:

• Tissue-type plasminogen activator (t-PA) contributes to extracellular matrix degradation in human fetal membrane rupture.
• The regulation of t-PA gene expression in extraembryonic development is not well understood.

Purpose of the Study:

• To investigate retinoic acids (RAs) as potential molecular regulators of t-PA expression in fetal membranes.
• To elucidate the molecular mechanisms underlying RA-mediated t-PA induction.

Main Methods:

• Primary amniotic membrane explants and WISH cells were used to study t-PA expression.
• Gene reporter assays, site-directed mutagenesis, immunoprecipitation, and chromatin immunoprecipitation were employed.
• RNA interference (shRNA) and specific antagonists were utilized to assess the role of RAR-beta.

Main Results:

• Retinoic acids (RAs) induced t-PA mRNA and protein in a time-dependent manner.
• RA-induced t-PA expression involves a two-step regulation, mediated by retinoid receptors (RARs/RXRs) binding to a DR5 element and SP1 factor.
• RAR-beta was identified as a crucial mediator in the RA-induced t-PA regulation in fetal membranes.

Conclusions:

• Retinoic acids (RAs) are key regulators of tissue-type plasminogen activator (t-PA) expression in human fetal membranes.
• The RA-mediated t-PA regulation occurs via a complex, two-step mechanism involving specific retinoid receptors and transcription factors.
• RAR-beta plays a significant role in the induction of t-PA, highlighting its importance in fetal membrane physiology.