Involvement of eIF2α in halofuginone-driven inhibition of TGF-β1-induced EMT

Halofuginone (HF) is an extract from the widely used traditional Chinese medicine (TCM) Dichroa febrifugathat facilitates the recovery of wounds and attenuates hepatic fibrosis. However, the role of HF in theepithelial-mesenchymal transition (EMT) of IPEC-J2 cells remains unclear. The current study explored theanti-EMT effect of HF in IPEC-J2 cells and illustrates its molecular mechanism. Transforming growth factorb1 (TGF-b1), as a recognized profibrogenic cytokine, decreased the level of the epithelial marker E-cadherinand increased the level of the mesenchymal markers, such as N-cadherin, fibronectin (FN), vimentin (Vim),and a-smooth muscle actin (a-SMA), in IPEC-J2 cells depending on the exposure time and dose. HF markedlyprevented the EMT induced by TGF-b1. Dissection of the mechanism revealed that HF inhibited IPEC-J2 cellEMT via modulating the phosphorylation of SMAD2/3 and the SMAD2/3-SMAD4 complexnuclear translocation. Furthermore, HF could promote the phosphorylation of eukaryotic translation initiationfactor-2a (eIF2a), which modulates the SMAD signaling pathway. These results suggested that HF inhibitsTGF-b1-induced EMT in IPEC-J2 cells through the eIF2a/SMAD signaling pathway. Our findings suggest thatHF can serve as a potential anti-EMT agent in intestinal fibrosis therapy.