HDL is essential for atherosclerotic lesion regression in Apoe knockout mice by bone marrow Apoe reconstitution

Although studies in mice have suggested that lesion regression is feasible, the underlying mechanisms remain largely unknown. Here we determined the impact of high-density lipoprotein (HDL) on atherosclerosis regression outcome. Atherosclerotic lesion dynamics were studied upon bone marrow transplantation-mediated re-introduction of apolipoprotein E (Apoe) in Apoe knockout mice. Probucol was used to pharmacologically deplete HDL. Restoration of Apoe function was associated with an initial growth of atherosclerotic lesions and parallel decrease in lesional macrophage foam cell content (47 ± 4% at 4 weeks versus 72 ± 2% at baseline: p