Metabolic dysfunction-associated steatohepatitis (MASH) is highly prevalent among patients with type 2 diabetes. Cholesterol is one of several candidates causing hepatic inflammation and fibrosis. We hypothesized that by interrupting the synthesis of cholesterol, we could prevent a choline-deficient L-amino acid-defined high-fat diet (CDAHFD) C57BL/6J MASH mouse model. We found that cholesterol in liver lipid droplets accumulated on day 1, MASH-associated macrophage markers (Gpnmb and Trem2) mRNA expression and plasma ALT increased on day 2, macrophage crown-like-structures emerged on day 3, and fibrosis markers (Col1a1, αSMA) mRNA expression increased on day 7 in the CDAHFD-treated mice. Filipin staining demonstrated free cholesterol accumulation in liver lipid droplets. We next examined whether a N-acetylgalactosamine-modified antisense oligonucleotide (ASO) against coenzyme A synthase (Coasy), which catalyzes a rate controlling step in hepatic cholesterol synthesis, would reduce cholesterol in liver lipid droplets and inflammation/fibrosis in this model. Coasy ASO treatment prevented accumulation of cholesterol in liver lipid droplets (Control=1.02 ± 0.04 mg/g tissue; Coasy=0.68 ± 0.08, P<0.001) and decreased plasma ALT and liver inflammation/fibrosis markers expression. To examine whether these effects of the Coasy ASO were mediated by reductions in liver lipid droplet cholesterol we examined whether adding 2% cholesterol to the diet would prevent the Coasy ASO protective effect. Cholesterol treatment induced accumulation of cholesterol in liver lipid droplets (Coasy=0.68 ± 0.08 mg/g tissue; Coasy with cholesterol =1.40 ± 0.11, P<0.001) and abrogated the protective effects of the Coasy ASO on liver inflammation and fibrosis.
Conclusions: These data demonstrate that cholesterol in liver lipid droplets is a key mediator of MASH and hepatic Coasy knockdown is a potential therapeutic approach.
I. Sakuma: None. R.C. Gaspar: None. A. Nasiri: None. M. Kahn: None. M. Guerra: None. D. Yimlamai: None. S. Murray: Employee; Ionis Pharmaceuticals. M. Perelis: Employee; Ionis Pharmaceuticals. W. Barnes: Employee; Ionis Pharmaceuticals. D.F. Vatner: None. K. Petersen: None. V. Samuel: None. G.I. Shulman: None.