Functional Genomics Link REST to Endothelial Plasticity and Atherosclerosis

Area of Science:

• Genetics and Molecular Biology
• Cardiovascular Research
• Cell Biology

Background:

• Genome-wide association studies (GWAS) have identified numerous loci associated with coronary artery disease (CAD) pathogenesis.
• The underlying molecular mechanisms for these GWAS associations, particularly in endothelial cells, remain largely unexplored.

Purpose of the Study:

• To prioritize endothelial-specific genetic loci associated with atherosclerosis using a multitrait colocalization approach.
• To investigate the functional role of the identified locus targeting the RE1-silencing transcription factor (REST) gene in CAD.

Main Methods:

• Applied a multitrait colocalization approach across expression quantitative trait loci (eQTLs) in atherosclerosis-relevant cell types.
• Utilized in vitro CRISPR interference, Pcsk9-overexpressing mouse models with endothelial-specific Rest knockout, and RNA-sequencing (RNA-seq).
• Performed single-nucleus RNA sequencing and Cleavage under Targets and Tagmentation (CUT&Tag) sequencing for mechanistic insights.

Main Results:

• A conserved regulatory element in a chromosome 4 locus was found to increase CAD risk by decreasing REST expression in endothelial cells.
• Endothelial-specific Rest knockout in mice led to increased atherosclerotic plaque formation, macrophage, and lipid deposition.
• REST silencing in human aortic endothelial cells induced endothelial-to-mesenchymal transition (EndMT), increased permeability, and migration, involving L1CAM activation and TGFb signaling.

Conclusions:

• RE1-silencing transcription factor (REST) acts as a crucial repressor in endothelial cells.
• REST constitutively inhibits endothelial-to-mesenchymal transition (EndMT), thereby protecting against atherosclerosis.
• These findings reveal a novel protective role for REST in cardiovascular health.