Narciclasine Alleviates Endothelial Inflammation and Atherosclerosis Initiation by Inhibiting Histone Lactylation-Mediated NF-κB Activation

Glycolysis-derived lactate serves as a substrate for lysine lactylation, an epigenetic modification playing critical transcriptional regulatory roles in inflammatory diseases. Endothelial inflammation, characterized by upregulated glycolysis, initiates atherosclerosis, yet the contribution of histone lactylation remains undefined. Although narciclasine exhibits anti-inflammatory and antioxidant properties, its impact on endothelial inflammation in atherosclerosis is unknown. Connectivity Map (CMap) analysis predicted narciclasine as an inhibitor of oscillatory shear stress and TNF-α-induced endothelial inflammation. In vitro, treatment of human umbilical vein endothelial cells (HUVECs) with 20 nM narciclasine significantly suppressed ox-LDL-induced expression of VCAM1, ICAM1, SELE, and CCL2, reduced reactive oxygen species (ROS) production, and inhibited monocyte adhesion and migration. In vivo, administration of narciclasine (0.02 mg/kg) attenuated carotid artery endothelial inflammation and macrophage infiltration, consequently reducing early atherogenesis in partial carotid ligation model in ApoE^-/- mice. Mechanistically, ox-LDL upregulated GLUT1 and PFKFB3 expression, enhancing endothelial glycolysis and lactate production. Increased lactate accumulation promoted histone H3 lysine 18 lactylation (H3K18la). Both pharmacological (2-DG, DCA) suppression of lactate production or genetic (LDHA, P300 silencing) suppression reduced H3K18la levels and inhibited ox-LDL-induced endothelial inflammation. Reanalysis of public CUT&Tag data (GEO: GSE267661) and chromatin immunoprecipitation (ChIP) validation revealed ox-LDL-induced enrichment of H3K18la at key promoters of NF-κB pathway genes (TRAF2, TRAF6, RIP1, cIAP1, RELA). Narciclasine treatment suppressed GLUT1 and PFKFB3 expression, thereby reducing H3K18la enrichment and inhibiting NF-κB pathway activation. Our findings provide novel insights into the functional role of lactylation-mediated epigenetic regulation in glycolysis-driven endothelial inflammation. Collectively, this study identifies narciclasine as a potential therapeutic candidate, which mitigates endothelial inflammation and early atherosclerosis by targeting a glycolysis-H3K18la network linked to NF-κB activation.