Figure 2.

Uptake of lipoproteins is not a prerequisite for the inhibition of SAA‐induced IL‐1β secretion. (a) Primary macrophages were subjected to LDL (1 mg mL⁻¹) or preformed LDL‐SAA complexes (1 mg mL⁻¹ LDL, 25 μg mL⁻¹ SAA) with or without cytochalasin D (1 μg mL⁻¹) for 18 h. After this, cellular lipids were extracted and analysed by thin layer chromatography. The protein concentration was determined by the Lowry method. The data are expressed as μg cholesterol ester (CE) per mg cellular protein. (b) Primary macrophages were subjected to preincubation with native or oxidised HDL₃ and LDL (200 μg mL⁻¹) and cytochalasin D (1 μg mL⁻¹) for 1 h and then exposed to SAA (3 μg mL⁻¹) for 18 h. After the incubation, cell culture media were analysed for IL‐1β concentrations by ELISA. Data are expressed relative to respective control (SAA activation). Mean values shown are from 2 (a) or 3 (b) independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.