TAG content and de novo synthesis during macrophage to foam cell transition.
(A and B) oxLDL treatment of RAW 264.7 cells (left panel) and BMDM (right panel). Cells were treated for 24 h with oxLDL and fixed and stained with Oil red-O to visualize lipid droplets. (C and D) LD area per cell (average of 100 cells per treatment) and increase in TAG content in macrophages after 24 h oxLDL treatment compared to the control. (G-H) Cells were treated for 24 h with oxLDL and 2.2 mM [14C]acetate or 0.1 mM [14C]oleate (OA). Lipids were extracted, and lipid classes were analyzed by TLC. Radiolabeled lipids were quantified with a Bioscan scanner. (E and F) Cells were treated with oxLDL, and GPAT activity was assayed in total membranes in the presence or absence of NEM. NEM-sensitive GPAT activity (corresponding to GPAT3/4 activity) was calculated by subtracting NEM-resistant GPAT activity from the total. NTC: non-oxLDL treated control. Data are from three independent experiments. *** p<0.001, ** p<0.01, * p<0.05.