Fig. 1.

Accumulation of lipids in THP-1 macrophages incubated with aggLDL and/or VLDL. THP-1 macrophages were treated for 6 days at 37°C in RPMI containing 1% FBS and TPA (50 ng/ml) alone or with 100 μg protein/ml of aggLDL and/or VLDL. The cells were harvested, and the cellular lipid levels were determined as described in Materials and Methods. A: Incubation of THP-1 with aggLDL produced a dramatic increase in total cellular cholesterol seen primarily as a significant increase (P < 0.05) in CE (light-gray portion of bar). Although on average the FC (dark-gray portion of bar) also increased to almost double the control levels, this difference was not statistically significant. Incubation with both aggLDL and VLDL reduced the cellular CE accumulation compared with that seen with aggLDL alone. B: Incubation of cells with VLDL produced a significant (P < 0.05) increase in cellular TG levels compared with control or aggLDL-treated cells both when used alone or in combination with aggLDL. Values are the mean ± SEM for three experiments. Within each panel, bars with the same letter indicate that means were not statistically different. All other comparisons were significantly different (P < 0.05).