Mechanisms of AGE-induced VSMC phenotypic switching and macrophage modulation in human abdominal aortic aneurysms.

Abstract

Advanced glycation end products (AGEs) have been associated with vascular pathologies including abdominal aortic aneurysms (AAAs), although their causal role remains unclear. In this study, we observed significant accumulation of AGEs in human AAAs, particularly in cases associated with intraluminal thrombus (ILT). In vitro, AGE exposure induced vascular smooth muscle cell (VSMC) migration and suppressed contractility, accompanied by reduced expression of contractile markers (α-SMA and MYH11) and elevated MMP-2. This phenotypic transformation was linked to the activation of the NLRP3 inflammasome and RAGE/RhoA/ROCK signaling, and was reversible upon inhibition of RAGE, RhoA, or ROCK. In macrophages, AGE pretreatment had minimal effects on basal cytokine secretion but attenuated LPS-induced IL-6 and IL-1β release and NF-κB activation. Co-culture experiments further revealed that AGE-pretreated macrophages reduced LPS-driven pro-migratory effects on VSMCs. Spatial transcriptomics demonstrated enriched AGE-RAGE signaling in αSMA+ VSMCs and CD68+αSMA+ macrophage-like VSMCs in ILT-containing AAAs. Overall, these associative findings implicate AGE-RAGE signaling in AAA pathogenesis and warrant further investigation to establish causality.