A liver divided
Three separate teams have directly converted human fibroblasts to proliferative liver cells and thus eliminated a key drawback of using induced pluripotent stem cells to treat damaged livers-the inability of the resulting differentiated cells to repopulate damaged liver.1-3
Each team had a different twist on getting the cells to divide, but the common thread was that fibroblasts were directly programmed to cell states that are part of the hepatocyte differentiation pathway. Next steps could include taking the protocols' lentiviral manipulations out of the equation and further improving the maturation of the resulting hepatocytes.
Patients with chronic liver disease live for an average of 12 years with compensated cirrhosis before they enter a state of rapid decline marked by ascites, encephalopathy and other complications.4 Because the demand for livers for transplantation exceeds the supply, a logical alternative is to use induced pluripotent stem (iPS) cell technology.
The idea is straightforward: take a patient's own cells, usually fibroblasts, revert them to an iPS cell state and then differentiate them in vitro into an autologous supply of hepatocytes. The problem comes at the last step, with different research