[Atorvastatin inhibits scavenger receptor A and monocyte chemoattractant protein-1 expressions in foam cell]

To investigate the effects of atorvastatin on expressions of scavenger receptor A and secretion of monocyte chemoattractant protein-1 (MCP-1) in foam cells.

THP-1 cells were induced to differentiate into macrophages by PMA and treated with 0.1% BSA (control), ox-LDL (100 mg/L) or ox-LDL plus atorvastatin (5, 10, 20 micromol/L) for 24 hours. MCP-1 concentration in cell substratum was measured by ELISA. Scavenger receptor A expression was observed under fluorescent microscope after incubated with DiI-Ac-LDL. The relationship between concentration of MCP-1 and the activity of scavenger receptor A was also analyzed.

Compared to the control cells, MCP-1 concentration in ox-LDL treated cells was significantly increased after 6 hours, peaked at 12 hours and was still significantly increased after 24 hours (all P < 0.05 vs. baseline). The activity of scavenger receptor A was also significantly increased in ox-LDL treated cells (P < 0.01 vs. control). The activity of scavenger receptor A proteins correlated positively to the concentration of MCP-1 in ox-LDL treated cells (r = 0.683, P < 0.01). Atorvastatin significantly attenuated these changes in a dose-dependent manner.

Scavenger receptor A and MCP-1 expressions were significantly increased in the course of monocyte lines THP-1 differentiating into macrophages and foam cells. The anti-atherosclerosis effect of atorvastatin might be partly achieved by inhibiting the secretion of MCP-1 and expression of scavenger receptor A in foam cells.