Objective        To determine the protective effect of bone marrow mesenchymal stem cells (BMSCs) implantation in SD rats after extracorporeal hepatectomy and orthotopic liver autotransplantation.       Methods        SD rat BMSCS were isolated

cultivated and purified

and then labeled with green fluorescent protein (GFP) by lentivirus vector pLV.EX2d.P/hygro-EF1AEmGFP. Then the cells at passage 3 to 5 was adjusted into cell suspension of 2×10

6

cells/ml. A

total of 70 SD rats were randomly divided into BMSCs group (n=30)

normal saline group (n=30) and sham operation group (n=10). The rats from the former 2 groups received extracorporeal hepatectomy and orthotopic liver autotransplantation (left liver lobe was resected)

and then the rats from BMSCs group were given BMSCs transplantation through portal vein

and those from normal saline group were injected with normal saline. The rats wre sacrificed in 12

24

48

72 and 168 h respectively. Serum and liver tissue specimens were collected and tested by the biochemistry

TUNEL and Western blot analysis for liver function

hepatocyte apoptosis and serum levels of TGF-β1

Bcl-2

and bax.       Results        BMSCs were successful cultured and identified.Compared with the normal saline group

BMSCs transplantation resulted in a lower postoperative mortality

significantly better postoperative liver function in 12

24

and 72 h

and significantly decreased hepatocyte apoptosis. Expression of TGF-β1 at protein level was significantly decreased in 24 h

but not in 24 and 72 h

while that of bax was significantly increased and that of Bcl-2 was significantly increased in all above 3 time points (P0.05).        Conclusion        Portal vein implantation of BMSCs improves postoperative liver function in SD rats after the extracorporeal hepatectomy and orthotopic liver autotransplantation

through influencing Bcl-2/bax ratio to attenuate hepatocyte apoptosis

and possibly through TGF-β 1 noncorrelation pathway.