Transforming Growth Factor-β1 Induced Epithelial-Mesenchymal Transition in Hepatic Fibrosis

The epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) are crucial for the regulation of cellular plasticity during liver fibrosis. Transforming growth factor (TGF)-β1 is an important cytokine for the induction of the EMT in liver fibrosis. TGF-β1 signaling induces the EMT through various signaling mechanisms and is the predominant agent mediating these fibrotic changes. Chronic exposure to TGF-β1 induces the transition of hepatocytes to collagen-producing mesenchymal cells, prolonged exposure of hepatocytes to TGF-β1 increases the expression of collagen and induces cytoskeletal rearrangement that resembles the EMT. These morphological and molecular alterations may provide the foundation for liver fibrosis. This review discussed the relation and mechanisms between EMT and liver fibrosis and ulteriorly elaborated on TGF-β1 induced EMT and each of their roles in liver fibrosis. Better understanding of the cellular and molecular characteristics of the cirrhotic hepatocyte may enable the development of chemo-preventative agents for liver fibrosis.