A similar inhibitory effect of myriocin on hepatic triglyceride production via suppression of hepatic SREBP-1c was recently reported in a diet-induced hamster model of insulin resistance. We also examined the role of ceramide in the pathogenesis of atherosclerosis in NAFLD. Significant increases in hepatic expression of HL and LPL genes with a WD suggest that an increase in VLDL conversion to LDL production in LDLR-/- mice contribute to the development of atherosclerosis. The increased plasma ApoB levels with a WD and their reduction with myriocin confirm that change in ApoB production was mainly driven by hepatic triglyceride synthesis. Myriocin treatment increased HDL flux, increased hepatic expression of genes involved in RCT and almost completely abolished atherosclerosis induced by a WD. These data suggest that myriocin affects both HDL biogenesis and functionality, including RCT. These results are also in agreement with the recent finding that L-NAME hydrochloride depletion of the ceramide metabolite SM in cell membrane promotes cholesterol efflux, the key step in RCT. In the current study, inhibition of ceramide and SM biosynthesis by myriocin also was associated with improved plasma lipids and lipoproteins and significantly protected GW9662 against atherosclerosis. Based on these results we postulate that regulation of lipid and lipoprotein metabolism by ceramides could be one of the possible mechanisms that link diet-induced NAFLD and atherosclerosis. In addition to its role in hepatic lipid and lipoprotein metabolism, circulating ceramide may also promote atherosclerosis through direct effects on endothelial function. It was recently shown that liver-derived ceramides along with triglycerides and cholesterol are packaged with VLDL and released into the circulation. Lipidomics analysis of different lipoprotein fractions demonstrated that indeed, plasma ceramides are concentrated in VLDL and LDL particles. Ceramide-loaded LDL has been shown to stimulate TNF-�� and IL-6 production in cultured macrophages through NF-��B activation suggesting that ceramide-induced cytokine production in the circulation can target endothelial cells, which would exacerbate atherosclerosis through inflammatory mechanisms.