FIGURE 1.

Lipoxins modulate oxidative burst in human neutrophils from patients with atherosclerosis and healthy controls. Whole blood from healthy controls (n = 7) or patients with atherosclerosis (n = 6) was exposed to an inflammatory stimulus, either in the absence or presence of lipoxin A₄ (LXA₄: 500 nM) or lipoxin B₄ (LXB₄: 500 nM). Neutrophil reactive oxygen species (ROS) production was measured by flow cytometry and reported as DHR positivity. The percentage ROS‐positive neutrophils (DHR+) was determined in relation to a 1% baseline, which was set using an unstimulated control sample and kept constant throughout the analysis. (A) Neutrophil ROS production was measured as % positive cells (left panel) and cellular mean fluorescence intensity (MFI) (right panel), in controls (white bars) and patients (gray bars). The cells were untreated (Unstim.) or stimulated with chemotactic peptide N‐formyl‐Met‐Leu‐Phe (fMLP, 0.4 μM) opsonized Escherichia coli (1.5 × 10⁷), or phorbol 12‐myristate 13‐acetate (PMA, 1 μM). Representative histograms of the MFI DHR‐signal in respective conditions are shown for controls (dashed line) and patients (solid line). (B) LXA₄ (blue bars) and LXB₄ (green bars)‐induced changes to ROS production was calculated as the log₂ fold change relative to respective vehicle‐treated condition. The cells were stimulated as indicated. The bar graphs show ROS levels as % positive cells (left panel) and cellular mean fluorescence intensity (MFI) (right panel). Representative histograms of the MFI DHR‐signal in respective conditions are shown for vehicle (black line), LXA₄ (blue line), and LXB₄ (green line). Assuming non‐Gaussian distribution of the human samples, statistical analysis was determined using Mann–Whitney U test when comparing two groups, and Kruskal–Wallis test with Dunn's post hoc comparisons when comparing more than two groups. Data are presented as mean ± standard error of the mean (SEM). Statistical significance is indicated as *p < .05, **p < .01, ***p < .001, ****p < .0001