Abstract 20473: Impact of p53 activation on Lesional Macrophage Proliferation And Atherosclerosis In Mice
Rationale: Cell proliferation and cell cycle control mechanisms are believed to play central roles in the pathogenesis of atherosclerosis. The transcription factor Zinc fingerprotein 148 (Zfp148) was recently shown to maintain cell proliferation under oxidative conditions by suppressing p53, a checkpoint protein that arrests proliferation inresponse to various stressors. It is established that inactivation of p53 accelerates atherosclerosis, but whether increased p53 activation confers protection against thedisease remains to be determined.
Objective: We aimed to test the hypothesis that Zfp148 deficiency reduces atherosclerosis by unleashing p53 activity.
Methods and Results: Mice harbouring a gene-trap mutation in the Zfp148 locus (Zfp148gt/+) were bred onto the Apoe-/- genetic background and fed a high-fat or chowdiet. Loss of one copy of Zfp148 markedly reduced atherosclerosis without affecting lipid metabolism. Bone marrow transplantation experiments revealed that the effectorcell is of hematopoietic origin. We next investigated whether p53 is part of the underlying mechanism. Peritoneal macrophages from Zfp148gt/+Apoe-/- mice showedincreased levels of phosphorylated p53 compared to controls, and atherosclerotic lesions from Zfp148gt/+Apoe-/- mice contained fewer proliferating cells and moreapoptotic cells. Zfp148gt/+Apoe-/- mice were further crossed with p53-null mice (Trp53-/-). There was no difference in atherosclerosis between Zfp148gt/+Apoe-/- mice andcontrols on a Trp53+/- genetic background.
Conclusions: Zfp148 deficiency increases p53 activity and protects against atherosclerosis without affecting lipid metabolism. The protective effect is entirely dependent onp53 and suggests that drugs that increase p53 activity may be useful in the treatment of atherosclerosis.
Author Disclosures: V.I. Sayin: None.
- © 2016 by American Heart Association, Inc.