Figure 5.

Lysosomal inhibitor enhances TNFα-induced LDL lipid accumulation. The cells were pre-treated with 0 or 100 ng/mL TNFα (+) for 24 h in the presence of serum. Subsequently, in the continued presence of TNFα, the cells were treated with 0.5 µg/mL Dil-LDL, plus 50 or 200 µg/mL [³H]CE-LDL, and containing 0 or 50 µM chloroquine diphosphate (Cl-quine), +, a lysosomal blocker, without serum. After 24 h, the intracellular fluorescence (A,B) or radioactivity (C) was determined. The separation of #cells in A is an artificact of preparation prior to lysing the cells for radioactivity. The circumferential accumulation of the Dil-LDL in the presence of chloroquine is apparent (A). The images are 20× magnifications. n = 2.