Dietary supplementation with NR, but not SIRT1 overexpression, completely corrects hepatic steatosis and steatohepatitis in DN‐NAMPT mice under normal chow. (A) Effect of SIRT1 overexpression or NR on expression of lipid regulatory genes in livers of WT and DN‐NAMPT mice. *P < 0.05 versus WT, #
P < 0.05 DN‐NAMPT + Ad‐SIRT1 versus DN‐NAMPT + Ad‐lacZ, &
P < 0.05 DN‐NAMPT + NR versus DN‐NAMPT by ANOVA analysis. n = 8 for each group. (B) Representative images of Oil Red O staining for the livers of WT and DN‐NAMPT mice. (C) Effect of SIRT1 overexpression or NR on lipid triglyceride and cholesterol in livers of WT and DN‐NAMPT mice. T‐Cho, total cholesterol. *P < 0.05 versus WT, #
P < 0.05 DN‐NAMPT + Ad‐SIRT1 versus DN‐NAMPT + Ad‐lacZ, &
P < 0.05 DN‐NAMPT + NR versus DN‐NAMPT by ANOVA analysis. n = 8 for each group. (D–E) Immunohistochemistry staining showing the effects of NR and SIRT1 overexpression on Kupffer cell accumulation (D) and TNF‐α protein (D) and mRNA (E) expression. *P < 0.05 versus WT, #
P < 0.05 DN‐NAMPT + Ad‐SIRT1 versus DN‐NAMPT + Ad‐lacZ, &
P < 0.05 DN‐NAMPT + NR versus DN‐NAMPT by ANOVA analysis. n = 8 for each group. Effects of NR and SIRT1 overexpression on hepatic MDA level (F) and blood ALT and AST levels (G). *P < 0.05 versus WT, #
P < 0.05 DN‐NAMPT + Ad‐SIRT1 versus DN‐NAMPT + Ad‐lacZ, &
P < 0.05 DN‐NAMPT + NR versus DN‐NAMPT by ANOVA analysis. n = 8 for each group.