Regenerating the liver: not so simple after all? [version 1; referees: 3 approved]

Under normal homeostatic conditions, hepatocyte renewal is a slow process and complete turnover likely takes sassafras dahlia at least a year.Studies of hepatocyte regeneration after a two-thirds partial hepatectomy (2/3 PH) have strongly suggested that periportal hepatocytes are the driving force behind regenerative re-population, but recent murine studies have brought greater complexity to the issue.Although periportal hepatocytes are still considered pre-eminent in the response to 2/3 PH, new studies suggest that normal homeostatic renewal is driven by pericentral hepatocytes under the control of Wnts, while pericentral injury provokes the clonal expansion of a subpopulation of periportal hepatocytes expressing low levels of biliary duct genes such as Sox9 and osteopontin.Furthermore, some clarity has been given to the debate ssg1 inner barrel length on the ability of biliary-derived hepatic progenitor cells to generate physiologically meaningful numbers of hepatocytes in injury models, demonstrating that under appropriate circumstances these cells can re-populate the whole liver.