F iPS and iHL. It was found that both iPS and iHL reduced serum ALT and AST levels, however, the injury areas were not synchronously reduced by iHL. Moreover, iHL promoted less hepatocytes proliferation than iPS did. The actual causes of the functional and histological discordance of iHL are unclear. But the sameFigure 2. Localization of iPS in injured liver. The iPS and iHL were labeled with a red fluorescent dye (DiI) before use. (A) At 24 h post-injury, frozen sections of livers from different groups were observed. The background of Red fluorescent was present at 
the PBS control. The strong red fluoresence signals indicate the iPS or iHL localized in the liver. (B) The representative flow-cytometry diagrams showed that iPS localized in liver. Flow cytometry assay were used to calculate the percentage of iPS engrafted in the liver. doi:10.1371/journal.pone.0050577.gIP-10 in Liver Injury Post iPS TransplantationIP-10 in Liver Injury Post iPS TransplantationFigure 3. Changes of DprE1-IN-2 hepatic chemokines after iPS infusion in injured mice. (A) iPS-induced changes of cytokines in the liver were evaluated by cytokine array. (B) The hepatic expression of IP-10 and MIG were increased after CCl4 injury. iPS infusion further increase their expressions, but not for iTAC. At 48 h post-injury, the hepatic expression of IP-10 and MIG MedChemExpress BIBS39 decreased but IP-10 remained at levels significantly higher than those of the CCl4 group (n = 6, *p,0.05 vs. normal control, #p,0.05 vs. CCl4 group). (C) Hepatic IP-10 at 24 h post-injury was measured in homogenized liver extract by ELISA and western blot. iPS infusion significantly increased hepatic IP-10 in CCl4-injured liver. (n = 4, *p,0.05 vs. normal control, #p,0.05 vs. CCl4 group). doi:10.1371/journal.pone.0050577.gpresentation has ever been observed in cell transplantation using mesenchymal stem cells-derived hepatocytes [25]. One possible factor that may account for this discrepancy could be that differentiation in the in vitro culture conditions were unlike the native in vivo environment. Even though the iHL have displayed characteristic functions of primary hepatocyte, the in vitro differentiated iHL might have lost some of the potency of the iPS to resist injury and to promote repopulation of liver parenchyma cells. Kuo et al. had found a similar result that the mesenchymal stem cells-derived hepatocytes did not offer better functionality than the undifferentiated mesenchymal stem cells [17]. Another factor might be the limited success rate of hepatic engraftment after cell transplantation. We found that the 1516647 amount of iHL localized in the damaged liver was much less than that of iPS. It is possible that there were not enough numbers 
of engrafted iHL to produce similar protective effects as iPS. The critical contribution of cell engraftment has been suggested in a study that chimeric mice whose entire liver engrafted with iPS cell-derived hepatocytes recovered from liver failure rapidly [11]. Therefore, whether the iPS cell-derived hepatocytes act as a better cellular source for transplantation required further investigation. Cytokines and chemokines are important mediators of immune and inflammatory responses. We found two chemokines, IP-10 (or CXCL10) and MIG (or CXCL9), increased prominently in the injured liver after iPS infusion. They are two related chemokines belonging to the CXC subfamily [26]. Both have similar activities and share a common CXCR3 receptor. Increased expression of IP-10 has been found in c.F iPS and iHL. It was found that both iPS and iHL reduced serum ALT and AST levels, however, the injury areas were not synchronously reduced by iHL. Moreover, iHL promoted less hepatocytes proliferation than iPS did. The actual causes of the functional and histological discordance of iHL are unclear. But the sameFigure 2. Localization of iPS in injured liver. The iPS and iHL were labeled with a red fluorescent dye (DiI) before use. (A) At 24 h post-injury, frozen sections of livers from different groups were observed. The background of Red fluorescent was present at the PBS control. The strong red fluoresence signals indicate the iPS or iHL localized in the liver. (B) The representative flow-cytometry diagrams showed that iPS localized in liver. Flow cytometry assay were used to calculate the percentage of iPS engrafted in the liver. doi:10.1371/journal.pone.0050577.gIP-10 in Liver Injury Post iPS TransplantationIP-10 in Liver Injury Post iPS TransplantationFigure 3. Changes of hepatic chemokines after iPS infusion in injured mice. (A) iPS-induced changes of cytokines in the liver were evaluated by cytokine array. (B) The hepatic expression of IP-10 and MIG were increased after CCl4 injury. iPS infusion further increase their expressions, but not for iTAC. At 48 h post-injury, the hepatic expression of IP-10 and MIG decreased but IP-10 remained at levels significantly higher than those of the CCl4 group (n = 6, *p,0.05 vs. normal control, #p,0.05 vs. CCl4 group). (C) Hepatic IP-10 at 24 h post-injury was measured in homogenized liver extract by ELISA and western blot. iPS infusion significantly increased hepatic IP-10 in CCl4-injured liver. (n = 4, *p,0.05 vs. normal control, #p,0.05 vs. CCl4 group). doi:10.1371/journal.pone.0050577.gpresentation has ever been observed in cell transplantation using mesenchymal stem cells-derived hepatocytes [25]. One possible factor that may account for this discrepancy could be that differentiation in the in vitro culture conditions were unlike the native in vivo environment. Even though the iHL have displayed characteristic functions of primary hepatocyte, the in vitro differentiated iHL might have lost some of the potency of the iPS to resist injury and to promote repopulation of liver parenchyma cells. Kuo et al. had found a similar result that the mesenchymal stem cells-derived hepatocytes did not offer better functionality than the undifferentiated mesenchymal stem cells [17]. Another factor might be the limited success rate of hepatic engraftment after cell transplantation. We found that the 1516647 amount of iHL localized in the damaged liver was much less than that of iPS. It is possible that there were not enough numbers of engrafted iHL to produce similar protective effects as iPS. The critical contribution of cell engraftment has been suggested in a study that chimeric mice whose entire liver engrafted with iPS cell-derived hepatocytes recovered from liver failure rapidly [11]. Therefore, whether the iPS cell-derived hepatocytes act as a better cellular source for transplantation required further investigation. Cytokines and chemokines are important mediators of immune and inflammatory responses. We found two chemokines, IP-10 (or CXCL10) and MIG (or CXCL9), increased prominently in the injured liver after iPS infusion. They are two related chemokines belonging to the CXC subfamily [26]. Both have similar activities and share a common CXCR3 receptor. Increased expression of IP-10 has been found in c.
