Macrophage ABCA1 and ABCG1, but not SR-BI, promote macrophage reverse cholesterol transport in vivo
J. Clin. Invest. Xun Wang, et al. 117:2216 doi:10.1172/JCI32057 [Go to this article.]

Figure 6
Double knockdown of ABCA1 and ABCG1 in J774 macrophages impairs cholesterol efflux in vitro and RCT in vivo. (A) Quantitative analysis of mRNA expression of abca1 and abcg1 in control, ABCG1-KD, and ABCA1/ABCG1-DKD cells by quantitative RT-PCR. Data are expressed as fold change ± SD and normalized to mouse 18S rRNA. (B) Cholesterol efflux assay was performed as described in Figure 1 using lipid-free apoA-I (10 μg/ml) as the acceptor. (C) Cholesterol efflux was determined as described above, except cells were incubated for 2 hours either in the presence of absence of probucol (20 μM) prior to the addition of 2.5% mouse whole serum as the acceptor. Data are expressed as mean ± SD; n = 3. **P < 0.01; ***P < 0.001. (D and E) The RCT assay was performed as described in Figure 1 with [³H]cholesterol-labeled, acLDL-loaded, and LXR agonist–treated control, ABCG1-KD, and DKD cells. n = 6 mice per group. Data are expressed as the percentage of tracer relative to total cpm tracer injected ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001. (D) Time course of [³H]cholesterol distribution in plasma. Areas under the curve were determined and compared. (E) Fecal [³H]tracer levels. Feces were collected continuously from 0 to 48 hours.