YAP1/TAZ Mediates Rumen Epithelial Cell Proliferation but Not Short-Chain Fatty Acid Metabolism In Vitro.

Promoting rumen development is closely related to the health and efficient growth of ruminants. The transcriptional co-activators Yes1-associated protein (YAP1) and WW domain-containing transcription regulator protein 1 (TAZ) are key regulators of the mammalian epithelium. In the present study, we assessed the impact of YAP1/TAZ on rumen epithelial (RE) cell proliferation using their activator GA-017 (GA) and inhibitor verteporfin (VP). We also investigated whether YAP1/TAZ-dependent alteration was involved in the RE developmental process induced by sodium butyrate (SB). The results indicated that GA promoted RE cell proliferation, while VP disrupted RE cell proliferation. The Hippo, Wnt, and calcium signaling pathways were altered following the regulation of YAP1/TAZ. Upon YAP1/TAZ activation, the expression of / increased. However, when YAP1/TAZ was inhibited, the expression of decreased. In the SB-treated cells, YAP1/TAZ-induced changes were not observed. SB increased the expressions of differentiated cell marker genes and genes involved in short-chain fatty acid (SCFA) metabolism, while YAP1/TAZ did not. Thus, YAP1/TAZ could be potential targets for regulating RE cell proliferation but not for SCFA metabolism. SB could not affect YAP1/TAZ. These findings broaden our understanding of the role of YAP1/TAZ and their regulators in RE development.