In vascular systems, macrophages can engulf circulating oxidized (ox) low-density lipoprotein (LDL), leading to the accumulation of intracellular lipid droplets, which forms foam cells. Macrophage-derived foam cells are an important therapeutic target for atherosclerosis. However, quantifying intracellular lipid droplets in macrophages is difficult. The purpose of this study was to use high-content screening (HCS) and fluorescence staining to analyze and quantify accumulation of intracellular lipid droplets in macrophages. A murine macrophage cell line RAW 264.7 was seeded in a 96-well black plate and treated with ox-LDL. After fixation, the cells were stained with the lipophilic and nuclear fluorescent dyes briefly. The number and mean fluorescence intensity of the intracellular lipid droplets in the macrophages were detected by an HCS reader. Using HCS to quantify lipid droplets in macrophages could be applied for antiatherogenic drug discovery, and its sensitivity is much higher than that of oil red O staining.
Keywords: foam cells; high-content screening; lipid droplets; macrophages; oxidized low-density lipoprotein.