Edaravone attenuates carbonyl-stress-driven ApoA-I carboxymethylation and macrophage cholesterol-handling dysfunction...

Area of Science:

• Biochemistry
• Cardiovascular Biology
• Metabolic Disease Research

Background:

• Diabetes mellitus significantly elevates atherosclerotic cardiovascular disease risk.
• The precise mechanisms by which carbonyl stress, particularly glyoxal, impacts high-density lipoprotein (HDL) function and contributes to atherosclerosis remain incompletely understood.
• Apolipoprotein A-I (ApoA-I) is the primary protein component of HDL, crucial for reverse cholesterol transport.

Purpose of the Study:

• To investigate the role of the glyoxal-apolipoprotein A-I (ApoA-I) pathway in diabetes-associated atherosclerosis.
• To evaluate the potential of edaravone as a therapeutic agent to modulate carbonyl stress and its effects on HDL function and atherosclerosis.
• To identify specific sites of glyoxal modification on ApoA-I and assess the functional consequences in macrophages and in vivo.

Main Methods:

• Analysis of plasma Nε-(carboxymethyl)lysine (CML) and glyoxal levels in a human cohort stratified by diabetes and coronary artery disease status.
• Site-resolved liquid chromatography-tandem mass spectrometry to identify glyoxal modification sites on ApoA-I.
• In vitro studies using macrophages to assess the impact of glyoxal-modified ApoA-I on cholesterol efflux, gene expression, and inflammatory pathways.
• In vivo studies using diabetic Ldlr-/- mice treated with edaravone to evaluate atherosclerotic burden and lesion characteristics.
• Single-cell transcriptomics to analyze cellular and molecular changes in atherosclerotic lesions.

Main Results:

• Plasma CML and glyoxal levels correlated with diabetes severity and coronary artery disease.
• Glyoxal preferentially modified ApoA-I at Lys23, Lys107, and Lys195, forming CML adducts detected in human plasma.
• In macrophages, glyoxal-ApoA-I impaired cholesterol efflux, reduced ABCA1/ABCG1 expression, increased lipid accumulation, and activated NF-κB and NLRP3 pathways.
• Edaravone attenuated ApoA-I CML formation, partially restored cholesterol efflux, and modulated inflammatory responses in vitro and in vivo.
• Edaravone treatment in diabetic mice reduced atherosclerotic burden and promoted beneficial macrophage and endothelial remodeling, with coordinated changes in lipid handling and inflammatory signaling.

Conclusions:

• Glyoxal-induced CML modification of ApoA-I is a key mechanism contributing to impaired macrophage cholesterol handling and inflammation in diabetes-associated atherosclerosis.
• Edaravone demonstrates potential as a carbonyl stress modulator, offering cytoprotective and signaling benefits that warrant further investigation for therapeutic application in diabetic atherosclerosis.