Liver fibrosis: possible involvement of EMT.

Hepatic fibrosis is a wound-healing process in the liver with acute and chronic injury and is characterized by an excess production and deposition of extracellular matrix components. Hepatic stellate cells as well as portal fibroblasts play a pivotal role in the liver fibrogenesis. Regarding the origin of these mesenchymal cells, two hypotheses emerge. One hypothesis argues in favor of BM-derived progenitor cells and a second hypothesis favors epithelial-mesenchymal transition (EMT) in the local formation of these mesenchymal cells from hepatic epithelium. In this short review, we describe (1) the principle mechanisms of hepatic fibrosis, (2) the cells which play a crucial role in hepatic fibrosis, and (3) the possible involvement of EMT in the process of hepatic fibrosis and carcinogenesis. 2007 S. Karger AG, Basel