Stably transfected ABCA1 antisense cell line has decreased ABCA1 mRNA and cAMP-induced cholesterol efflux to apolipoprotein AI and HDL

Using a sensitive real time fluorescent PCR assay, ABCA1 mRNA levels were induced by 50–70-fold following 8Br-cAMP treatment of the RAW264 murine macrophage cell line, concomitant with the induction of cholesterol efflux to apoAI and HDL. A stably transfected ABCA1 antisense cDNA cell line was created, which led to 50–70% reductions in ABCA1 mRNA levels in basal and 8Br-cAMP-treated cells, and diminished to the same extent the 8Br-cAMP-mediated efflux of cholesterol to apolipoprotein AI and HDL. These data demonstrate that ABCA1 is necessary for the cAMP-induced lipid efflux to both apoAI and HDL.