Biochemistry of Liver Regeneration
Epithelial injury stimulates repair mechanisms that replace dead epithelial cells in various adult organs, including the liver. Unlike other organs, however, the liver is capable of efficiently reconstructing the entire tissue without scarring (i.e., regenerating) following acute resection of most of its mass. This suggests that adult livers may be particularly adept at reactivating, and appropriately modulating, morphogenic mechanisms that orchestrate tissue construction during fetal development. However, sometimes liver injury leads to progressive fibrosis and architectural distortion (i.e., cirrhosis), rather than effective regeneration. Whether repair results in regeneration or cirrhosis may depend upon the success with which developmental morphogenic mechanisms are reactivated and then repressed. This article reviews recent work which supports this hypothesis, focusing on how the activity of one developmental morphogenic signaling pathway (Hedgehog) is regulated during adult liver damage.
