Abstract
OBJECTIVES: To investigate the role of activating transcription factor 3 (ATF3) in atherosclerotic plaques for regulating inflammatory responses during atherosclerosis (AS) progression. METHODS: Human coronary artery specimens from autopsy cases were examined for ATF3 protein expression and localization using immunofluorescence staining and Western blotting. Apolipoprotein E-deficient (ApoE(-/-)) mouse models of AS induced by high-fat diet (HFD) feeding for 12 weeks were subjected to tail vein injection of adeno-associated virus serotype 9 (AAV9) to knock down ATF3 expression. After an additional 5 weeks of HFD feeding, the mice were euthanized for analyzing structural changes of the aortic plaques, and the expression levels of ATF3, inflammatory factors (CD45, CD68, IL-1β, and TNF-α), and NF-κB pathway proteins (P-IKKα/β and P-NF-κB p65) were detected. In the cell experiment, THP-1-derived foam cells were transfected with an ATF3-overexpressing plasmid or an ATF3-specific siRNA to validate the relationship between ATF3 and NF‑κB signaling. RESULTS: In human atherosclerotic plaques, ATF3 expression was significantly elevated and partially co-localized with CD68. ATF3 knockout in ApoE(-/-) mice significantly increased aortic plaque volume, upregulated the inflammatory factors, enhanced phosphorylation of the NF‑κB pathway proteins, and increased the expressions of VCAM1, MMP9, and MMP2 in the plaques. In THP-1-derived foam cells, ATF3 silencing caused activation of the NF‑κB pathway, while ATF3 overexpression suppressed the activity of the NF-κB pathway. CONCLUSIONS: AS promotes ATF3 expression, and ATF3 deficiency exacerbates AS progression by enhancing plaque inflammation via activating the NF-κB pathway, suggesting the potential of ATF3 as a therapeutic target for AS.