RESUMO
<p><b>OBJECTIVE</b>To investigate the effect of oxidized low-density lipoprotein (ox-LDL) on the expressions of sterol regulatory element binding protein-2 (SREBP-2) and hydroxymethylglutaryl CoA reductase (HMGCR) in the macrophages derived from monocytes of patients with acute coronary syndrome (ACS).</p><p><b>METHODS</b>LDL was oxidized by Cu2+ to prepare ox-LDL, and peripheral monocytes were isolated by density gradient centrifugation from patients with ACS diagnosed by coronary arteriography. Macrophages derived from the monocytes after phorbol myristate acetate (PMA) stimulation were treated with ox-LDL at the concentrations of 0, 20, 40, and 100 ng/ml, and the changes in the expressions of SREBP-2 and HMGCR were detected by real-time RT-PCR.</p><p><b>RESULTS</b>Compared with the control cells, the macrophages treated with ox-LDL showed significantly increased expressions of SREBP-2 and HMGCR mRNA (P<0.05). In cells treated with ox-LDL, the expressions of SREBP-2 and HMGCR mRNA differed significantly with the dose administered (P<0.05).</p><p><b>CONCLUSION</b>Within a defined dose range, ox-LDL can dose-dependently enhance the expressions of SREBP-2 and HMGCR mRNA in macrophages from patients with ACS.</p>