Experimental and bioinformatic analysis of cultured Bovine Endometrial Cells (BEND) responding to interferon tau (IFNT)

BACKGROUND In ruminants, embryo implantation depends on progesterone (P4) and interferon tau (IFNT) controlling endometrial function. IFNT antagonizes bovine endometrial cells (BEND) response to phorbol 12,13-dibutyrate (PDBU) through posttranscriptional regulation of gene expression. We have previously described microRNAs (miRNAs) profiles in bovine endometrium, detecting miR-106a, relevant for embryo maternal communication. In this study, we investigated the expression miR-106a and genes for prostaglandin-endoperoxide synthase 2 (PTGS2), phospholipase A2, group IVA (PLA2G4A), estrogen receptor 1 (ESR1) and progesterone receptor (PR) in response to IFNT in BEND cells and searched for interferon responsive factors (IRFs) binding sites in their promoter genomic regions. The aim of this study was to unravel the molecular mechanisms involved in IFNT signalling and its regulation of miR-106a. FINDINGS PTGS2 showed increased expression under PDBU, which was antagonized by IFNT. IFNT induced expression of PR and miR-106a and downregulation of ESR1 and PR. Bioinformatic analyses detected that PLA2G4A was associated to IRF-1 and IRF-6, while ESR1, PR and PTGS2 were associated to only IRF-6. All genes exhibit one motif per IRF, except miR-106a that had three binding sites for IRF-6. CONCLUSIONS We report the IFNT regulatory effect on miR-106a expression through IRF-6 in bovine endometrial cells. We identified a set of potential binding sites for IRF-1 and IRF-6 within the bovine genome. A set of candidate gene regions could be characterized where IFNT can act via IRFs to regulate the expression of proteins and miRNAs. Future studies will use these data to detect new IFNT regulatory mechanisms in the endometrium.