[The roles of Kupffer cells in the development and regression of liver fibrosis].

Hepatic fibrosis results from iterative hepatic injury with sustained inflammation, formation of scar tissue, loss of tissue architecture and organ failure. There is no doubt, from both human and animal studies, that too much or too protracted inflammation in the liver leads to excess scarring. During liver injury, Kupffer cells can quickly flood the hepatic milieu with soluble mediators, including oxidants, cytokines, and proteinases, which can affect stellate cell proliferation, migration, and differentiation. On the other hand, the contribution of Kupffer cells to regression of hepatic fibrosis has been demonstrated. These findings underscore the potential importance of hepatic macrophages in regulating both stellate cell biology and extracellular material degradation during regression of hepatic fibrosis. Therefore, biological characterization of Kupffer cells, their interactions with stellate cells in the cytokine environment are essential to understand the mechanisms underlying the progressive development of excessive scarring in the liver as well as the ability of the liver for tissue repair and recovery.