The NAMPT Inhibitor FK866 Attenuates DEN-Induced Liver Fibrosis in Mice

Chronic liver disease (CLD) poses a significant global health challenge, and liver fibrosis is a crucial process in the pathogenesis of CLD. However, effective interventions to halt and reverse the progression of liver fibrosis remain elusive. This study investigated the potential of the nicotinamide phosphoribosyltransferase (NAMPT) inhibitor FK866 in treating diethylnitrosamine (DEN)-induced liver fibrosis in mice. We first demonstrated that DEN-induced hepatic fibrosis in mice was accompanied by upregulation of hepatic NAMPT and poly (ADP-ribose) polymerase 1 (PARP1) expression. Administration of FK866 inhibited the increase in alanine aminotransferase and aspartate aminotransferase levels and reversed the histopathological changes associated with DEN-induced liver fibrosis. It also suppressed the elevated expression of fibrotic markers, such as fibronectin, collagen IV, laminin, and α-smooth muscle actin. Further studies revealed that this therapeutic effect was achieved by inhibiting the NAD⁺ level, as well as the protein expression of NAMPT, PARP1, and inflammatory factors, including interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α, and P65. In conclusion, FK866 exhibits therapeutic potential for the treatment of liver fibrosis.