YAP-TEAD Inhibition Impairs Interferon Tau-Induced Gene Expression and Reduces Integrin β1 Abundance in Primary Bovine Luteal Cells

The Hippo pathway effector Yes-associated protein (YAP), acting through TEA domain (TEAD) transcription factors, regulates transcriptional programs in ovarian tissues; however, its role in interferon tau (IFNT) signaling within bovine luteal cells has not been investigated. This study aimed to determine whether YAP-TEAD interaction is required for IFNT-induced interferon-stimulated gene (ISG) expression in primary bovine luteal cells and to perform an exploratory assessment of selected receptor genes (ITGB1, GRP78, VEGFR2). Primary luteal cells were treated with recombinant ovine IFNT (roIFNT; 1 ng/mL) in the presence or absence of verteporfin (VP; 0.1, 0.5, or 1.0 µM), a pharmacological YAP-TEAD inhibitor, and mRNA expression was quantified by RT-qPCR. VP dose-dependently suppressed YAP target genes (YAP1, CTGF, ANKRD1) and reduced roIFNT-induced expression of MX1, MX2, and OAS1, whereas ISG15 was unaffected. Steroidogenic gene expression (3β-HSD, P450scc, StAR) remained unchanged across treatments, indicating preserved cell viability. Among the exploratory receptor endpoints, VP decreased ITGB1 and increased GRP78 at the highest concentration, while VEGFR2 was unaffected. These findings indicate that YAP-TEAD activity contributes to IFNT-induced ISG responsiveness in bovine luteal cells, with preliminary evidence of effects on integrin-mediated signaling pathways.