3 The effects of liraglutide on endothelial cell-derived extracellular vesicles

<h3></h3> Liraglutide is a synthetic glucagon-like peptide-1 receptor „agonist that reduces the risk of major adverse cardiovascular events in patients with type 2 diabetes mellitus. Liraglutide acts on endothelial cells (ECs), which release more extracellular vesicles (EVs) in metabolic disease and mediate pro-inflammatory signalling.¹ We use a model of metabolic activation, stimulating human umbilical vein endothelial cells (HUVECs) with tumour necrosis factor-α and hyperglycaemia (15 mM), to investigate whether liraglutide modulates EC-EVs to lower cardiovascular risk. Clinically relevant doses (25-50 nM) of liraglutide had no effect on HUVEC viability (P&gt;0.05). 6-hour pre-treatment with liraglutide (25 nM) lowered vascular cell adhesion molecule-1 protein expression (P&lt;0.05) and interleukin-6 mRNA levels (P&lt;0.05) in metabolically stimulated HUVECs. Comparison of a published dataset² (McLean et al. 2022) of genes modulated by liraglutide pre-treatment before myocardial infarction in rodents with EV-associated genes (from Gene Ontology) suggested liraglutide modulates the release of EC-„EVs (P&lt;0.0001). HUVEC-derived EVs were isolated by ultra-centrifugation (2 hours at 120,000 x g). Nanoparticle Tracking Analysis showed metabolic stimulation of HUVECs augmented EC-EV release approximately two-fold (P&lt;0.05), but there was no difference between the concentration or size profiles of EVs derived from vehicle or liraglutide pre-treated HUVECs (P&gt;0.05). Metabolic stimulation enriched CD63 and CD9-positive EC-EVs sub-populations (P&lt;0.0001), but liraglutide had no effect on CD63, CD81, or CD9-positive EC-EV sub-populations (P&gt;0.05). Liraglutide modulates inflammatory gene and protein expression in endothelial cells in metabolic disease, but does not alter CD9, CD63 and CD81 subpopulation EC-EV release. Further research into the mechanisms underlying cardiovascular risk reduction is necessary for liraglutide to enter routine clinical practice for cardio-metabolic disease. <h3>References</h3> Akbar N, <i>et al</i>. Rapid neutrophil mobilization by VCAM-1+ endothelial cell-derived extracellular vesicles. <i>Cardiovasc Res</i> 2023;<b>119</b>:236–251. McLean BA, Wong CK, Kabir MG, Drucker DJ. Glucagon-like Peptide-1 receptor Tie2+ cells are essential for the cardioprotective actions of liraglutide in mice with experimental myocardial infarction. <i>Mol Metab</i> 2022;<b>66</b>.