Impact of sustained TGFβ-receptor inhibition on chromatin accessibility and gene expression in cultured endometrial MSC [ATAC-Seq]

Endometrial mesenchymal stem cells (eMSC) drive the extraordinary regenerative capacity of the human endometrium. Clinical application of eMSC for therapeutic purposes is hampered by spontaneous differentiation and cellular senescence upon large-scale expansion in vitro. A83-01, a selective TGFbeta receptor inhibitor, promotes pharmacological expansion of eMSC in culture by blocking differentiation and senescence. We subjected primary eMSC treated with A83-01 to Assay for Transposase Accessible Chromatin with sequencing (ATAC-seq) to map the underlying chromatin changes. A total of 185,084 open DNA loci were mapped accurately in EnSCs. ATAC-seq analysis demonstrated that sustained TGFbeta-R inhibition results in opening and closure of 3,555 and 2,412 chromatin loci, respectively. Motif analysis revealed marked enrichment of retinoic acid receptor (RAR) binding sites, which was paralleled by the induction of RARB. We subjected A83-01 treated and untreated human primary eMSC to Assay for Transposase Accessible Chromatin with sequencing (ATAC-seq) to map the underlying chromatin changes.