Kupffer cells dictate hepatic responses to the atherogenic dyslipidemic insult

Apolipoprotein-B (APOB)-containing lipoproteins cause atherosclerosis. Whether the vasculature is initially responding site, or if atherogenic-dyslipidemia affects other organs simultaneously, is unknown. Here we show that the liver responds to a dyslipidemic insult based on inducible models of familial hypercholesterolemia and APOB tracing. An acute transition to atherogenic APOB-lipoprotein levels resulted in uptake by Kupffer cells and rapid accumulation of triglycerides and cholesterol in the liver. Bulk and single-cell RNA-seq revealed an Kupffer cell-specific transcriptional program that was not activated by a high-fat diet alone, or detected in standard liver function or pathological assays, even in the presence of fulminant atherosclerosis. Depletion of Kupffer cells altered the dynamic of plasma and liver lipid concentrations, indicating that these liver macrophages help restrain and buffer atherogenic lipoproteins, whilst simultaneously secreting atherosclerosis-modulating factors into plasma. Our results place Kupffer cells as key sentinels in organizing systemic responses to lipoproteins at the initiation of atherosclerosis. Overall design: Liver samples from APOE cKO and D374Y mice and respective littermate controls. Biological replicates are indicated by the number at the end of each sample number. Mice were maintained on a choe diet for 10 days, or on a high fat diet for 4,8,12 or 20 weeks as indicated.