Figure 5. Sirt1 suppresses foam cell formation in atherosclerotic plaques. (A) Sirt1 reduces the uptake of oxidized low-density lipoprotein (oxLDL) by diminishing the expression of lectin-like oxidized LDL receptor-1 (Lox-1) via the deacetylation and suppression of the NF-κB signaling pathway, leading to a reduction of foam cell formation. (B) Sirt1 interacts with the liver X receptor (LXR) and promotes its deacetylation and subsequent activation. Activation of LXR upregulates the expression of ATP-binding cassette sub-family A member (ABCA) 1 and ABC sub-family G member (ABCG) 1, which leads to the reverse transport of cholesterol and the suppression of foam cell formation and cholesterol loading in macrophages. The induction of C-C chemokine receptor type 7 (CCR7) contributes to foam cell migration, resulting in a reduction of foam cell formation.