[Granulocyte colony-stimulating factor-mobilized autologous bone marrow stem cells promote the liver regeneration of partial liver transplant: an experiment with rats].

OBJECTIVE

To investigate the effects of granulocyte colony-stimulating factor (G-CSF)-mobilized autologous bone marrow stem cells on the liver regeneration of partial liver transplant.

METHODS

A 50% partial liver transplantation model as established by transplanting parts of the liver of female rats to the male rats with the equal weights that had had parts of their livers resected. Then the transplanted male rats were randomly divided into 3 equal groups: G-CSF + PLTx group that was injected hypodermically with recombinant human G-CSF (rhG-CSF) daily for 5 days and then underwent liver resection and 50% partial liver transplantation (PLTx); PLTx + G-CSF group that underwent PLTx and 3 hours after the transplantation received injection of rhG-CSF daily for 5 days, and PLTx control group that underwent PLTx and 3 hours later received injection of normal saline daily for 5 days. One, 3, 5, 7, and 14 days after the PLTx blood samples and livers were collected from 6 rats from each group, and one hour before the liver was taken bromodeoxyuridine (BrdU) was injected intraperitoneally to be integrated into the synthesis of DNA in the liver cells. Immunohistochemistry was used to detect the CD34 and BrdU-positive cells. In situ hybridization was used to detect the sry (sex-determining region) gene so as to determine the origin of the proliferating cells in the transplanted liver.

RESULTS

The 14-day survival rate of the G-CSF + PLTx group was 90%, significantly higher than those of the G-CSF + PLTx (60%) and PLTx group (50%) (both P < 0.05) with a significant difference between the latter 2 groups too (P < 0.05). The mitosis index of liver cells 3 days after the transplantation of the PLTx + G-CSF group was 30% +/- 5%, significantly higher than those of the G-CSF + PLTx group (24% +/- 7%) and PLTx group (24% +/- 6%) (both P < 0.05) without a significant difference between the latter 2 groups. The rate of BrdU-positive cells of the PLTx + G-CSF group was 42% +/- 6%, significantly higher than those of the G-CSF + PLTx group (38% +/- 4%) and PLTx group (34% +/- 8%) (both P < 0.05). The transplantation the mitosis index and rate of BrdU-positive cells decreased since the 7th days after transplantation in all 3 groups, however, with the same relationship among them. The numbers of CD34(+) cell around the portal area of the 2 G-CSF groups increased since the 3rd day after transplantation in comparison with the PLTx group, was the highest on the 3rd day for the G-CSF + PLTx group, and continued to increase in the PLTx + G-CSF group. Since the 3rd day after transplantation, sry-positive cells were seen in the hepatic sinusoid and portal area in the 2 G-CSF groups, and were rarely seen in the PLTx group.

CONCLUSION

G-CSF treatment after 50% PLTx significantly promotes liver regeneration and ameliorates the liver damage, thus raising the survival rate.