Abstract:Aim To study the effect of low density lipoprotein (LDL), oxidized low density lipoprotein (ox LDL), high density lipoprotein (HDL), oxidized high density lipoprotein (ox HDL)on the expression of ATP binding cassette transporter 1 (ABC1) mRNA in THP 1 cells. Methods Cultured THP 1 cells were induced into macrophage by 40 μg/L phorbol ester (PMA)for 48 h and then incubated with 20 mg/L and 120 mg/L LDL, ox LDL, HDL and ox HDL for 24 h, total RNA of THP 1 cells were abstracted, reverse transcription polymerase chain reaction (RT PCR) were performed to inspect of the expression of ABC1 mRNA. Results The expression of ABC1 mRNA in THP 1 cells increased mildly in the presence of low dose of LDL, ox LDL and ox HDL, and low dose of HDL showed almost no effect on ABC1 expression; on the contrary, the expression of ABC1 mRNA decreased obviously in the presence of high dose of LDL, ox LDL and ox HDL, while HDL caused a mildly decrease in ABC1 mRNA expression in THP 1 cells. Conclusions Low dose of LDL, ox LDL and ox HDL can increase the expression of ABC1 mRNA in THP 1 cells; while high dose of LDL, ox LDL, HDL and ox HDL suppress ABC1 mRNA expression in THP 1 cells. This may imply that the effect of different levels of lipoproteins and oxidized lipoproteins on ABC1 expression play an important role in atherogenesis.