Walnut oil affects cholesterol transport and storage in THP-1 macrophage-derived foam cells (MDFC). (A) Walnut oil increases cholesterol efflux. DMSO treated cells have 2.3% cholesterol efflux (of total 3H-Ch). Values of DMSO treated cells are normalized and expressed as 100%. (B) Expression change of genes related with cholesterol transport and storage following walnut oil treatment. Full names of all abbreviation are as described in Table S1 footnote. (C) Walnut oil affects gene expression related with lipogenesis and fatty acid oxidation. (D) Walnut oil treatment decreases SCD1 protein. Band intensities were determined by OptiQuant Image analysis software (Packard Instrument Co., Meriden, CT). (E) Effect of walnut oil on ABCA1 and ABCG1 protein levels. (F) Effect of SCD1 on cholesterol efflux. SCD1 overespression is shown by western blot. A total of 60 μg proteins were loaded on each lane of control (empty plasmid) and overexpression groups. Bars not sharing common letters (a, b or c) differ with P < 0.05. (G) Fatty acids affect SCD1 expression. Fatty acids are conjugated to BSA with a molar ratio of 4:1 modified from method described by Calder et al. . PA: palmitic acid; OA: oleic acid; LA: linoleic acid; ALA: alpha linolenic acid. (H) Fatty acids affect cholesterol efflux. Symbol * in all figure panels indicates a significant difference from respective control with P < 0.05. The data presented are means ± SEM of triplicate wells of two independent experiments.