biostudies-literatureCoassolo LNIDDK NIH HHSNovo Nordisk FondenNIGMS NIH HHSNIH HHS105802https://www.ebi.ac.uk/biostudies/studies/S-EPMC9830221biostudies-literatureUnknown26(1)Non-alcoholic fatty liver disease is a heterogeneous disease with unclear underlying molecular mechanisms. Here, we perform single-cell RNA sequencing of hepatocytes and hepatic non-parenchymal cells to map the lipid signatures in mice with non-alcoholic fatty liver disease (NAFLD). We uncover previously unidentified clusters of hepatocytes characterized by either high or low <i>srebp1</i> expression. Surprisingly, the canonical lipid synthesis driver <i>Srebp1</i> is not predictive of hepatic lipid accumulation, suggestive of other drivers of lipid metabolism. By combining transcriptional data at single-cell resolution with computational network analyses, we find that NAFLD is associated with high constitutive androstane receptor (CAR) expression. Mechanistically, CAR interacts with four functional modules: cholesterol homeostasis, bile acid metabolism, fatty acid metabolism, and estrogen response. Nuclear expression of CAR positively correlates with steatohepatitis in human livers. These findings demonstrate significant cellular differences in lipid signatures and identify functional networks linked to hepatic steatosis in mice and humans.iScienceMapping transcriptional heterogeneity and metabolic networks in fatty livers at single-cell resolution.PMC9830221K99 DK111916R01 DK125260R01 GM102365P30 DK116074S10 OD020141R00 DK111916NNF20OC0059462Yki-Jarvinen HZhao MAltman RBCoassolo LJung YTaylor NPNissen SBLiu TCharville GWSvensson KJfalseMapping transcriptional heterogeneity and metabolic networks in fatty livers at single-cell resolution.Non-alcoholic fatty liver disease is a heterogeneous disease with unclear underlying molecular mechanisms. Here, we perform single-cell RNA sequencing of hepatocytes and hepatic non-parenchymal cells to map the lipid signatures in mice with non-alcoholic fatty liver disease (NAFLD). We uncover previously unidentified clusters of hepatocytes characterized by either high or low <i>srebp1</i> expression. Surprisingly, the canonical lipid synthesis driver <i>Srebp1</i> is not predictive of hepatic lipid accumulation, suggestive of other drivers of lipid metabolism. By combining transcriptional data at single-cell resolution with computational network analyses, we find that NAFLD is associated with high constitutive androstane receptor (CAR) expression. Mechanistically, CAR interacts with four functional modules: cholesterol homeostasis, bile acid metabolism, fatty acid metabolism, and estrogen response. Nuclear expression of CAR positively correlates with steatohepatitis in human livers. These findings demonstrate significant cellular differences in lipid signatures and identify functional networks linked to hepatic steatosis in mice and humans.2023-01-01T00:00:00Z2023 Jan2024-12-04T12:35:10.47Z2024-12-04T12:35:10.47ZS-EPMC98302213663635410.1016/j.isci.2022.105802