Abstract Body: Atherosclerosis and metabolic-associated steatotic liver disease (MASLD) are highly prevalent diseases that frequently coexist and synergistically worsen cardiometabolic outcomes. Beyond shared risk factors such as obesity, diabetes, and dyslipidemia, MASLD independently accelerates atherosclerosis, yet the molecular mechanisms linking these pathologies remain poorly defined. Genome-wide association studies have identified Nck1 as a coronary artery disease risk locus with unclear functional significance. Although Nck1 and its paralog Nck2 redundantly regulate vascular development and angiogenesis, emerging evidence supports isoform-specific functions in adult vascular disease. We previously demonstrated that global Nck1 deletion reduces atherosclerotic plaque formation and that selective Nck1 inhibition attenuates pro-inflammatory endothelial activation under oscillatory shear stress.
Here, we investigated the endothelial-specific role of Nck1 in atherosclerosis and MASLD using inducible endothelial Nck1 knockout (iEC-Nck1 KO) mice fed a Western diet. Endothelial Nck1 deletion significantly reduced atherosclerotic plaque burden across multiple vascular regions, accompanied by decreased macrophage infiltration and suppression of pro-inflammatory gene expression. Mechanistically, Nck1 regulated endothelial inflammation through modulation of endoplasmic reticulum stress via the PERK–eIF2α–ATF3 signaling axis. Loss of Nck1 reduced ATF3 expression under disturbed flow conditions both in vitro and in vivo, while ATF3 silencing phenocopied the anti-inflammatory effects of Nck1 deletion, identifying ATF3 as a key downstream mediator. Importantly, endothelial Nck1 deletion did not impair ischemic angiogenesis.
In parallel, endothelial Nck1 deletion conferred protection against MASLD, evidenced by reduced hepatic inflammation, fibrosis, and dysregulated lipid metabolism. These transcriptomic changes were corroborated by decreased hepatic lipid accumulation, reduced collagen deposition, attenuated inflammatory markers, and lower serum ALT and AST levels. Pharmacologic inhibition using AX-024, a highly selective Nck1 inhibitor that has completed Phase Ia/Ib clinical trials, recapitulated these protective effects.
Collectively, these findings identify endothelial Nck1 as a shared mechanistic driver of both atherosclerosis and MASLD and support selective Nck1 inhibition as a promising, translatable dual-disease therapeutic strategy.