Bone marrow-derived mesenchymal stem cells promote hepatic regeneration after partial hepatectomy in rats.

OBJECTIVES Our goal was to study the ability of mesenchymal stem cells (MSCs) to stimulate liver regeneration after partial hepatectomy in rats. METHODS MSCs were isolated from bone marrow and cultured in vitro. Their characteristics were analyzed by flow cytometry. After 70% partial hepatectomy, Sprague-Dawley rats were randomly divided into three groups: a control group that was injected with saline, animals that received bone marrow-derived MSCs (BM-MSCs) by tail vein injection (the BM-MSC-TV group) and animals that received BM-MSCs by portal vein injection (the BM-MSC-PV group). The injected BM-MSCs were traced by labeling with 4',6-diamidino-2-phenylindole, and cell proliferations were determined by immunohistochemical staining with Ki-67 and 5-bromo-2'-deoxyuridine. RESULTS After the third passage, the cultured BM-MSCs had a fibroblast-like morphology and expressed high levels of stem cell markers CD29 and CD90. The levels of albumin rose significantly in the BM-MSC-TV and BM-MSC-PV groups compared with the control group. The number of 4',6-diamidino-2-phenylindole-positive liver cells in the BM-MSC-PV group was significantly higher than in the BM-MSC-TV group. The levels of Ki-67 and 5-bromo-2'-deoxyuridine were significantly higher in the BM-MSC-TV and the BM-MSC-PV groups than in the controls. CONCLUSION Taken together, these results indicate that BM-MSC injections enhance liver regeneration after partial hepatectomy in rats.