| First Author | Fullerton MD | Year | 2015 |
| Journal | J Lipid Res | Volume | 56 |
| Issue | 5 | Pages | 1025-33 |
| PubMed ID | 25773887 | Mgi Jnum | J:221882 |
| Mgi Id | MGI:5641794 | Doi | 10.1194/jlr.M058875 |
| Citation | Fullerton MD, et al. (2015) Salicylate improves macrophage cholesterol homeostasis via activation of Ampk. J Lipid Res 56(5):1025-33 |
| abstractText | Atherosclerosis stems from imbalances in lipid metabolism and leads to maladaptive inflammatory responses. The AMP-activated protein kinase (Ampk) is a highly conserved serine/threonine kinase that regulates many aspects of lipid and energy metabolism, although its specific role in controlling macrophage cholesterol homeostasis remains unclear. We sought to address this question by testing the effects of direct Ampk activators in primary bone marrow-derived macrophages from Ampk beta1-deficient (beta1(-/-)) mice. Macrophages from Ampk beta1(-/-) mice had enhanced lipogenic capacity and diminished cholesterol efflux, although cholesterol uptake was unaffected. Direct activation of Ampk beta1 via salicylate (the unacetylated form of aspirin) or A-769662 (a small molecule activator), decreased the synthesis of FAs and sterols in WT but not Ampk beta1(-/-) macrophages. In lipid-laden macrophages, Ampk activation decreased cholesterol content (foam cell formation) and increased cholesterol efflux to HDL and apoA-I, effects that occurred in an Ampk beta1-dependent manner. Increased cholesterol efflux was also associated with increased gene expression of the ATP binding cassette transporters, Abcg1 and Abca1. Moreover, in vivo reverse cholesterol transport was suppressed in mice that received Ampk beta1(-/-) macrophages compared with the WT control. Our data highlight the therapeutic potential of targeting macrophage Ampk with new or existing drugs for the possible reduction in foam cell formation during the early stages of atherosclerosis. |
