Endothelial ARHGEF26 is an angiogenic factor promoting VEGF signalling

Area of Science:

• Cardiovascular Genetics
• Molecular Biology
• Angiogenesis Research

Background:

• Genetic studies link the ARHGEF26 locus to coronary artery disease (CAD) risk.
• The precise mechanisms by which ARHGEF26 variants contribute to CAD remain unclear.

Purpose of the Study:

• To investigate the functional role of the ARHGEF26 locus in CAD pathogenesis.
• To elucidate the molecular pathways through which ARHGEF26 variants influence vascular health.

Main Methods:

• Conditional analysis of ARHGEF26 locus in relation to vascular phenotypes.
• In vitro studies using human endothelial cells (ECs) to assess ARHGEF26 function and interactions.
• Quantitative mass spectrometry to analyze CAD-risk variants.
• In vivo studies involving global or EC-specific deletion of ARHGEF26 in mouse models of atherosclerosis.

Main Results:

• The sentinel CAD-risk signal at ARHGEF26 is associated with non-lipid vascular phenotypes.
• ARHGEF26 enhances endothelial cell (EC) angiogenic capacity and interacts with angiogenic factors.
• A CAD-risk coding variant (rs12493885, p.Val29Leu) leads to a gain-of-function ARHGEF26, boosting proangiogenic signaling.
• ARHGEF26 is essential for EC angiogenesis, promoting VEGFR2 macropinocytosis and VEGF-dependent vessel sprouting.
• ARHGEF26 deletion in ECs significantly reduced atherosclerosis and increased plaque stability in mice.

Conclusions:

• ARHGEF26 plays a critical role in angiogenesis signaling.
• CAD-associated DNA variants in ARHGEF26 may increase risk by enhancing VEGF-dependent angiogenesis.