Impact of dietary cholesterol on Macrophages during non-alcoholic steatohepatitis progression

Inflammation, mediated by liver-resident Kupffer cells (KCs) and recruited infiltrating macrophages (IMs), plays a critical role in NAFLD pathogenesis. Cholesterol induces pro-inflammatory cytokine production by macrophages and has been identified as a key factor involved in progression from simple steatosis to NASH. In this study, using the fructose, palmitate, cholesterol & trans-fat (FPC) diet model which recapitulates human NAFLD, we aimed to determine the impact of cholesterol manipulation on NAFLD progression/regression and macrophage phenotype in vivo.The transcriptomic evaluation of hepatic macrophages from mice fed with FPC diet contained the highest concentration of cholesterol (1.25%) suggest these cells might contribute to liver inflammation, steatohepatitis, and hepatocarcinoma pathways during the progression phase. In our NASH model, we fed C57BL/6J mice with the Fructose, Palmitate, Cholesterol, and Trans-Fat (FPC) diet containing different concentrations of cholesterol: 1.25%, 0.2%, and 0.05% (control) for 20 weeks (progression phase). Then, we reduced the cholesterol in the FPC diet, keeping it at 0.05% for additional ten weeks (regression phase). At the end of each phase, we euthanized the animals. We harvested the hepatic non-parenchymal cells and sorted the hepatic macrophages for RNAseq analysis.