Inhibition of histone deacetylases in human endometrial stromal cells promotes extracellular matrix remodelling and inhibits embryo invasion

Abstract

Trophoblast invasion into the maternal decidua requires the action of metalloproteinases (MMPs) to degrade extracellular matrix (ECM) proteins. In turn, decidual cells express tissue inhibitors of MMPs (TIMPs) that restrain trophoblast invasion. Gene expression is post-transcriptionally regulated by histone deacetylases (HDACs) that unpacks condensed chromatin activating gene expression. The aim of this study was to analyse the effect of histone acetylation of human endometrial stromal cells (hESCs) on the expression of TIMPS hESCs were treated with HDAC inhibitor Trichostatin A (TSA) and the thophoblast invassion was assessed. hESCs from endometrial biopsies (n = 3) were isolated and treated with TSA or vehicle for 48hrs. Quantitative PCR for MMP2, MMP9, TIMP1, TIMP3 and uPA and zymograms for MMP2 and MMP9 activity were investigated. TSA pretreated hESCs for 48 h. vs control were used for wound healing and trophoblast invasion assays. For all studies, at least 3 different experiments were performed. Statistical analyses: t-Student. Inhibition of HDAC with TSA increases the mRNA expression of TIMP-1 and TIMP-3 (13- and 2-fold, respectively) while decreases MMP2 (14-), MMP9 (2.5-) and uPA (25-). Gelatine zymograms show a decrease in total MMP2 but also in the active form of MMP2 suggesting that TSA alters the expression of ECM components and its modulators. hESC TSA pretreated cells are 65% less motile and 50% less invasive than control cells. This phenotype correlates with the molecular change in the ECM described. Moreover, the potential invasion of mouse embryos in TSA treated hESCs is severely reduced compared to control (50% less) Our results demonstrate that histone acetylation reduces MMPs and increase their inhibitors in hESCs disrupting the balance of ECM modulators provoking a restrain of trophoblast invasion. These findings are important as an epigenetic mechanism that can be used to control trophoblast invasion