Abstract
Objective: To investigate the role of neutrophil elastase inhibitor, sivelestat, in preventing and treating nonalcoholic steatohepatitis (NASH) and its underling mechanisms. Methods: A total of forty 4-week-old male C57BL/6J ApoE-/-mice were equally divided into the following four groups: standard chow (SC)+isotonic saline; SC+sivelestat; high-fat, high-cholesterol (HFHC) diet+isotonic saline; and HFHC+sivelestat. These mice were treated with above methods for 12 weeks. Blood and liver tissue samples were collected to measure biochemical parameters, hepatic steatosis and non-alcoholic fatty liver disease (NAFLD) activity score (inflammation) were evaluated by oil red O staining and HE staining, respectively. The mRNA and protein expression levels of hepatic inflammatory cytokines, CD68, and F4/80 were determined by quantitative RT-PCR and immunohistochemistry, respectively. Comparison of means between the four groups was made by one-way analysis of variance, and comparison between any two groups was made by the LSD or SNK method (for data with homogeneity of variance) or the Tamhane or Dunnett method (for data with heterogeneity of variance). Results: Mice fed with an HFHC diet for 12 weeks developed typical pathological features of NASH compared with those fed with SC. Compared with mice fed with HFHC diet without sivelestat, those treated with HFHC and sivelestat exhibited the following features: (1) significantly reduced fast blood glucose, blood cholesterol, and hepatic biochemical parameters, as well as increased insulin sensitivity; (2) significantly reduced NAFLD activity score (5.71±1.11 vs 3.16±1.16, P < 0.05); (3) reduced monocyte chemoattractant protein-1 and tumor necrosis factor -α; (4) significantly reduced mRNA levels of CD68 and F4/80; and (5) reduced expression of CD68 in the liver. Conclusion: Sivelestat alleviates the hepatic steatosis and inflammation of NASH in mice by inhibiting the activation of Kupffer cells.