Synergistic amelioration of cholestatic liver fibrosis by combined total astragalus saponins and AAV8.Numb-Exon3 through modulation of hepatic progenitor cell differentiation.

BACKGROUND

Despite our previous findings that both total astragalus saponins (TAS) and hepatic AAV8.Numb-Exon3 overexpression (AAV8.Numb-Ex3OE) are effective against cholestatic liver fibrosis (CLF), the synergistic effect and mechanism of their combination remain unknown. This study was designed to investigate this combination therapy and elucidate its underlying molecular mechanisms.

METHODS

A rat model of CLF was induced by bile duct ligation and subsequently treated with combination therapy. Evaluations included serum biochemical parameters, liver histopathology, hepatic hydroxyproline (Hyp) content, expression levels of key molecules in the Notch signaling pathway, hepatic progenitor cells (HPCs) differentiation, ductular reaction (DR), and liver regeneration. In vitro, WB-F344 cells were induced toward a cholangiocyte-like phenotype, and the influence of TAS on HPCs differentiation was assessed following LV.Numb-Ex3 transfection.

RESULTS

The combination therapy more effectively improved serum biochemistry, reduced hepatic inflammation and collagen deposition, and lowered hepatic Hyp content compared to TAS or AAV8.Numb-Ex3OE monotherapy. Mechanistically, the combination therapy further suppressed differentiation of HPCs into cholangiocytes and inhibited DR, while promoting HPC-to-hepatocyte differentiation and enhancing liver regeneration.

CONCLUSION

The combination of TAS and AAV8.Numb-Ex3OE exerts a synergistic anti-fibrotic effect in CLF by redirecting HPCs differentiation fate. These findings provide experimental support for the development of novel combinatorial strategies against liver fibrosis.