Fig. 3

Monocytes show increased uptake of LDL from SLE patients. a and b THP-1 cells were incubated with LDL isolated from SLE patients (n = 19) and HCs (n = 8). THP-1 cells phagocytosed significantly more LDL from SLE patients and showed greater foam cell formation (NBD-positive area: 2501 ± 401.2 AUs vs. 524.1 ± 59.9 AUs, respectively; p < 0.001). c Human fibroblast cells were incubated with LDL from SLE patients or HCs, and β-galactosidase activity (a surrogate marker for cellular senescence) was measured. β-galactosidase activity was higher in fibroblasts treated with SLE-LDL (blue) than in those treated with HC-LDL. d SLE-LDL induced significantly higher β-galactosidase activity than HC-LDL (β-gal positive area: 70.9 AUs vs. 16.3 AUs, respectively; p < 0.001). Representative images (×400 magnification) from at least three independent experiments are shown. Data are expressed as the mean and SEM. AU arbitrary units, gal galactosidase, HC healthy control, MDA malondialdehyde, NBD 22-(N-7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino-23, 24-bisnor-5-cholen-3-ol, SLE systemic lupus erythematosus