Fig 2: Expression of pro-opiomelanocortin (POMC) in human atherosclerotic plaques. (A) Pro-opiomelanocortin (POMC) expression in atherosclerosis-free control arteries (left internal thoracic artery; LITA, n = 24) and in endarterectomy samples from the carotid artery (n = 29), abdominal aorta (n = 15) and femoral artery (n = 24). LITA samples served as controls and they were histologically verified to be atherosclerosis-free. *P < 0.05 for the indicated comparison (one-way ANOVA and Bonferroni post hoc test). (B) POMC expression in stable and unstable plaque phenotypes in a subgroup of advanced plaques (stage V and VI). Exact P-value (two-tailed Student’s t test) is given in the graph. (C) Correlation between POMC mRNA levels and general macrophage markers in control LITA samples and in carotid, abdominal and femoral plaque samples. Pearson correlation coefficient (r) values are presented in the column graphs. *P < 0.05, **P < 0.01 and ***P < 0.001 for correlation significances.

Fig 3: Association of POMC transcript with M1/M2 macrophage and smooth muscle cell markers is attenuated in unstable advanced plaques. (A,B) Correlation between POMC mRNA levels and established M1 (grey columns) and M2 (black columns) macrophage markers in stable and unstable plaques. (C,D) Correlation between POMC mRNA levels and smooth muscle cell markers in stable and unstable advanced plaques. Pearson correlation coefficient (r) values are presented in the column graphs. *P < 0.05 and **P < 0.01 for correlation significances.

Fig 4: POMC expression is directly associated with reverse cholesterol transporters in carotid artery plaques. (A–C) Correlations between POMC expression and ATP-binding cassette transporter A1 (ABCA1), G1 (ABCG1) and scavenger receptor class B member 1 (SCARB1) expression in carotid (left panel), abdominal (middle panel) and femoral (right panel) atherosclerotic plaques. Pearson correlation coefficients (r) and P values are presented in the graphs.

Fig 5: POMC expression negatively correlates with reverse cholesterol transporters in the whole blood, but the association is abolished in coronary artery disease. (A–D) POMC, ABCA1, ABCG1 and SCARB1 mRNA levels in whole blood samples of patients with history of coronary artery disease (CAD) and of individuals without coronary lesions (non-CAD). Exact P values (two-tailed Student’s t test) are presented in the graphs. (E) Correlations between POMC expression and ABCA1, ABCG1 and SCARB1 expression in whole blood samples from non-CAD and CAD individuals. Pearson correlation coefficients (r) and P values are presented in the graphs. (F,G) Correlation between POMC mRNA levels and established M1 (grey columns) and M2 (black columns) macrophage markers in non-CAD (n = 48) and CAD (n = 47) whole blood samples. Spearman correlation coefficient (r) values are presented in the column graphs. The dashed lines are placed at 0.39 and -0.39 that represent the correlation level between POMC and ABCA1/SCARB1. *P < 0.05 for correlation significances.