ROLE OF EPITHELIAL MESENCHYMAL TRANSITION IN HEPATIC FIBROGENESIS

Liver fibrosis is a gradual process of increased secretion and decreased degradation of extra-cellular materials. Two cell types are now well recognized as being involved in liver fibrosis, i.e. hepatic stellate cells (HSCs) and portal mesenchymal cells. T iis process is initiated by the damage of hepatic cells, which leads to activation of hepatic stellate cells that differentiate into myofibroblasts leading to the formation of liver fibrosis. On the other hand, the epithelial-mesenchymal transition and mesenchymal-epithelial transition are crucial for the regulation of cellular plasticity during liver fibrosis. The EMT is a process in which molecular reprogramming leads epithelial cells to adopt a mesenchymal phenotype. During EMT, epithelial cells gain mesenchymal features which include changes in the expression of epithelial markers. The EMT process plays fundamental roles during embryogenesis, tissue fibrosis, and carcinogenesis. As multiple experimental studies of liver fibrosis have confirmed that established liver fibrosis is reversible upon cessation of the causative agent, modulation of the EMT markers could be promising as potential therapeutic agents. Better understanding of the molecular cascades of intracellular fibrogenic signaling and genetic factors that controlling the expression of EMT markers would be a powerful strategy for early diagnosis and treatment liver fibrosis at the genetic level. Activating or silencing of the responsible genes may be an efficient and more specific approach for treating liver fibrosis either through the arrest of EMT or the induction of MET.