Figure 1. Mitochondria are required for cholesterol efflux in macrophages and are predicted to be regulated by miR-33.
(A) Human THP-1 macrophages transfected with control anti-miR or anti-miR33 were cholesterol-loaded for 24h before pre-treatment with oligomycin for 1h, and subsequently incubated with apoA1 for 6h. % cholesterol efflux is shown as a proportion of total radiolabeled cholesterol in the cell. (B) Peritoneal macrophages from wild-type C57BL6 or Pgc-1α-/- mice were loaded with or without cholesterol for 24h, and cholesterol efflux to apoA1 was measured for 6h. % cholesterol efflux is shown as a proportion of total radiolabeled cholesterol in the cell. (C) Bioinformatic pathway analysis using the DAVID gene tool and Gene Set Enrichment Analysis predicted that miR-33 regulates multiple mitochondrial genes. Predicted miR-33 targets are depicted as yellow circles; interacting downstream genes are shown as violet circles; genes outlined in blue are previously confirmed miR-33 target genes, and dotted lines are novel miR-33 target genes confirmed in this study.