The Impairment of Macrophage-to-Feces Reverse Cholesterol Transport during Inflammation Does Not Depend on Serum Amyloid A
Figure 3
Endotoxemia does not alter hepatic accumulation of macrophage-derived 3H-cholesterol, regardless of the presence of SAA. WT and SAAKO mice were injected subcutaneously with PBS or 0.8 μg/g LPS as indicated, followed by intraperitoneal injection of 3H-cholesterol-labeled J774 macrophages 4 hr later. (a) Radioactivity in liver was determined 24 hr after macrophage injection (28 hr after LPS injection). The data shown were compiled from 3 separate experiments (n = 4-5 per group per experiment) after normalization to PBS-injected WT mice. Values are the mean ± SEM. Liver counts for PBS-injected WT and SAAKO mice were similar, ranging from 3.9% to 8.5% of the injected tracer for the 3 experiments. (b) SR-BI in total liver lysates (10 μg protein) was detected by immunoblotting and quantified by densitometry. Results from each of the 3 experiments (n = 4-5 per group per experiment) were expressed relative to PBS-injected WT mice after normalization to β-actin. A representative western blot is shown. (c) Fu5AH hepatoma cells were preincubated for 1 hr with or without 10 μM BLT-1 and then for 6 hr with media ± BLT-1 supplemented with 5% serum obtained from mice 24 hr after administration of 3H-cholesterol-labeled macrophages (28 hr after LPS injection). The amount of radioactivity that was taken up by cells in the presence of BLT-1 is indicated by the shaded portion of the bars.
