Effect of cholesterol overload on gene expression of RAW264 macrophages

Hepatocyte death plays a critical role in the disease progression from simple steatosis to non-alcoholic steatohepatitis (NASH). We have previously reported that hepatocyte death locally induces phenotypic changes in the macrophages surrounding the corpse and remnant lipids, thereby promoting liver fibrosis in a murine model of NASH. Here, we demonstrated free cholesterol was accumulated in macrophages around dead hepatocytes containing cholesterol crystals. In vitro experiments revealed that cholesterol-induced lysosomal stress triggered profibrotic activation in macrophages. This study provides evidence that dysregulated cholesterol metabolism in macrophages would be a novel mechanism of NASH. RAW264 macrophages were treated with cholesterol crystals (500 μg/ml) with or without β-cyclodextrin polyrotaxane for 24 hours. RNA sequencing analysis was performed to investigate the lysosomal stress response induced by cholesterol crystals.