Background/aims: Hepatic oval cells play an important role in liver regeneration when proliferation of mature hepatocytes is inhibited. The aim of this study was to examine the effect of hepatocyte growth factor (HGF), or vascular endothelial growth factor (VEGF) on proliferation of oval cells in the Solt-Farber rat model.
Methodology: One hour after 70% partial hepatectomy, 2-acetyl-aminofluorene-induced damaged rats were infected intravenously with recombinant adenoviral vectors, encoding rat HGF or human VEGF, or Escherichia coli beta-galactosidase as a control.
Results: The plasma HGF concentrations in the HGF-transferred rats were elevated compared with the other groups at 4 and 7 days after hepatectomy. Oval cells were confirmed by positive staining of both cytokeratin-19 and alpha-fetoprotein. Oval cells around the portal tracts in the HGF or VEGF-transferred rats increased in number compared with the control rats at 7 and 9 days after hepatectomy. The proliferating cell nuclear antigen labeling indices of oval cells and the hepatic regeneration rate after hepatectomy were significantly augmented by the HGF or VEGF treatment. Moreover, cyclin E expression was elevated in the HGF-treated rats.
Conclusions: In the Solt-Farber rat model, HGF or VEGF gene injection effectively promoted liver regeneration after hepatectomy mainly with increased proliferation of hepatic oval cells.