Exogenous Ganglioside GM3 Attenuates Atherosclerosis via Multi-Organ Modulation of Lipid Metabolism

Background: Atherosclerosis (AS) remains a leading cause of cardiovascular mortality worldwide and is significantly driven by hyperlipidemia. While ganglioside GM3 is known to regulate cellular lipid metabolism, its systemic pharmacological effects on atherosclerosis remain unclear. This study aims to evaluate the anti-atherosclerotic efficacy of exogenous GM3 and elucidate its underlying systemic mechanisms. Methods: C57BL/6N ApoE^-/- mice fed a high-fat diet were intravenously treated with exogenous GM3 (1 or 4 mg/kg) every three days for 12 weeks. Atherosclerotic progression and lipid profiles were evaluated through histological analyses of the aortic arch and aortic sinus, alongside biochemical and molecular assessments of plasma, hepatic, and intestinal tissues. Results: GM3 treatment significantly reduced plaque formation in the aortic arch and aortic sinus, along with decreased plasma levels of triglycerides, total cholesterol, and LDL-C. Mechanistically, GM3 suppressed hepatic VLDL secretion by downregulating ApoB100 and MTTP expression. Concurrently, hepatic lipid clearance was enhanced via the upregulation of Ldlr, Scarb1, and Lrp1. GM3 also lowered circulating PCSK9 levels and reduced intestinal cholesterol absorption by decreasing NPC1L1 expression. Although GM3 promoted lipid accumulation in the liver, no evidence of liver dysfunction or systemic toxicity was observed. Conclusions: Exogenous GM3 acts as a potent multi-target modulator that attenuates atherosclerosis by coordinating hepatic lipoprotein metabolism and restricting intestinal cholesterol uptake. This multi-organ metabolic partitioning strategy highlights the potential of GM3-based therapeutics for managing complex dyslipidemia.