Oxymatrine Alleviates Atherosclerosis by Regulating Macrophage Senescence via the SIRT1-P53 Signaling Pathway.

Oxymatrine (OMT) inhibited macrophage senescence and improved atherosclerosis progression in both in vivo and in vitro models.

• High-fat diet-fed ApoE-/- mice were used as the in vivo atherosclerosis model.
• oxLDL-induced macrophage senescence models were used for in vitro experiments.
• OMT treatment reduced markers of macrophage senescence in both model systems.
• OMT delayed macrophage senescence-induced foam cell formation, which contributes to atherosclerotic plaque development.

The anti-atherosclerotic effects of OMT were mediated through regulation of SIRT1, as identified by network pharmacology analysis and confirmed by biological experiments.

• Network pharmacology analysis identified SIRT1 as a key target of OMT in ameliorating atherosclerosis.
• Pharmacological inhibition of SIRT1 using EX527 abolished the effects of OMT.
• Gene silencing using SIRT1 shRNA also aborted the functional effects of OMT.
• These results confirmed the pivotal role of SIRT1 in mediating OMT's therapeutic effects.

OMT enhanced the interaction between SIRT1 and P53, promoting P53 deacetylation and subsequent ubiquitination and degradation.

• OMT treatment increased SIRT1-P53 interaction as assessed by pharmacological intervention assays.
• Enhanced SIRT1 activity led to deacetylation of P53.
• Deacetylated P53 underwent ubiquitination and subsequent proteasomal degradation.
• Treatment with Idasanutlin (a P53 stabilizer/MDM2 inhibitor) attenuated the functional effects of OMT, confirming the pivotal role of P53 in OMT's mechanism of action.

OMT directly binds to SIRT1 protein and stabilizes it, as confirmed by molecular docking, CETSA, and DARTS assays.

• Molecular docking analysis predicted a direct binding interaction between OMT and SIRT1.
• Cellular Thermal Shift Assay (CETSA) confirmed that OMT stabilizes SIRT1 protein against thermal denaturation.
• Drug Affinity Responsive Target Stability (DARTS) assay further validated direct binding of OMT to SIRT1.
• Protein stabilization by OMT was associated with enhanced SIRT1 enzymatic activity.

Macrophage senescence was identified as an important pathological risk factor for atherosclerosis in the context of this study.

• oxLDL-induced macrophage senescence was used as a disease-relevant in vitro model.
• Senescent macrophages contributed to foam cell formation, a key step in atherosclerotic plaque development.
• OMT's inhibition of macrophage senescence was mechanistically linked to its atheroprotective effects.
• The study situates macrophage senescence as a recently identified pathological risk factor for atherosclerosis.

OMT was identified as a promising therapeutic candidate for atherosclerosis based on its multi-layered mechanism targeting the SIRT1-P53 signaling pathway.

• OMT demonstrated anti-atherosclerotic effects both in vitro and in vivo.
• The mechanism involves SIRT1 stabilization, enhanced deacetylase activity, P53 degradation, and reduced macrophage senescence.
• The study used network pharmacology, pharmacological intervention, gene silencing, molecular docking, CETSA, and DARTS to validate the mechanism.
• Authors conclude OMT is 'a promising therapeutic candidate for AS.'