PMC

Study flow chart.

ABCA1 expression and its function among study groups at baseline. A: ABCA1 protein expression was suppressed in macrophages from NCAD and CAD smokers compared with those from nonsmokers (each group, n = 6). B: Densitometry (p = 0.033, p < 0.001 vs. nonsmoker). C: ABCA1 mRNA was dramatically suppressed in CAD smokers but was upregulated in macrophages from NCAD smokers compared with that from nonsmokers (p < 0.001; each group, n = 10). D: ApoA-1-mediated cholesterol efflux was decreased in macrophages from CAD smokers (p < 0.001; n = 26) and NCAD smokers (p < 0.001; n = 24) compared with those from nonsmokers (n = 10) at baseline. ApoA-1-mediated cholesterol efflux was significantly lower from CAD smokers than from NCAD smokers (p = 0.017).

Changes of ABCA1 expression and function in macrophages from NCAD smokers after smoking cessation. A–C: ABCA1 protein expression did not change in macrophages from NCAD-smo and NCAD-abs (p = 0.458; n = 6). D: ABCA1 mRNA expression did not change in NCAD-smo and NCAD-abs (p = 0.267 and 0.089; n = 10). E: After 3 months of smoking cessation, ABCA1-mediated cholesterol efflux was increased significantly in NCAD-abs (p = 0.002; n = 12), whereas there was no change in NCAD-smo (p = 0.137; n = 12). F: The changes in ABCA1-mediated cholesterol efflux in NCAD-abs were not significantly different from those in NCAD-smo (p = 0.255).

Inhibition of ABCA1 expression from cigarette tar in THP-1-derived macrophages. THP-1 cells were differentiated into macrophages. Macrophages were incubated in medium containing tar or nicotine for 72 h. A: ABCA1 protein expression was stimulated by 100 ng/ml nicotine, which could be reversed by BTX. C: ABCA1 protein expression was inhibited by 0.1 g/l tar, which could be abolished by LXR agonist TO901317. B and D: ABCA1 mRNA was upregulated by nicotine (p = 0.006 vs. control) and downregulated by tar (p = 0.039 vs. control). The effects of nicotine and tar on ABCA1 mRAN expression could be removed by BTX (p < 0.001 vs. nicotine) and TO901317 (p < 0.001 vs. tar), respectively.

Changes of ABCA1 expression and function in macrophages after smoking cessation from CAD smokers. ABCA1 protein expression did not changed in CAD-smo (p = 0.156; n = 6) (A and C), but it was increased after smoking cessation for 3 months in CAD-abs (p = 0.007; n = 6) (B and 3). D: ABCA1 mRNA expression was upregulated in macrophages from CAD-abs (p = 0.042; n = 10). E: After 3 months of smoking cessation, ABCA1-mediated cholesterol efflux was increased significantly compared with baseline in CAD-abs (p = 0.004; n = 12), whereas there was no change in CAD-smo (p = 0.473; n = 10). F: After 3 months, ABCA1-mediated cholesterol efflux increased significantly in CAD-abs compared with that in CAD-smo (p = 0.036).