Lineage plasticity and reprogramming of epithelial cells during tissue injury and regeneration-lessons from the lineage plasticity of hepatocytes and cholangiocytes induced by liver injury.

Aside from successfully generating induced pluripotent stem cells from somatic cells, "reprogramming of differentiated cells" is a major technique for obtaining any type of target cells in vitro and in vivo by introducing critical transcription factors and using chemical compound combinations. In addition to these technical aspects, the physiological relevance of reprogramming has been extensively investigated, as growing evidence suggests that cellular reprogramming resulting in dedifferentiation or lineage conversion of a specific type of cell is associated with tissue injury and regeneration. We focus on cellular reprogramming in acute and chronically injured livers and summarize the molecular mechanisms governing the lineage transition between two types of liver epithelial cells, hepatocytes, and cholangiocytes.