Individuals with diabetes have an increased mortality due to the macro- and microvascular complications, which are commonly preceded by endothelial dysfunction. We have shown that endothelial microparticles (eMPs) are markers and mediators of vascular injury and pathology. However, their utility as a biomarker of hyperglycemia-induced endothelial damage and their influence on the vasculature remains unclear. We hypothesized that high glucose (HG) exposure alters eMPs protein composition, making them reflective of active signalling processes characteristic of a hyperglycemic environment. In addition, HG alters eMPs bioactivity, making them more potent inducers of oxidative stress, thrombosis and endothelial damage. Therefore, we assessed the exclusive effects of HG on eMPs formation, composition, and signalling. Results: Exposure of endothelial cells to high glucose for 24 hours caused a 3-fold increase in eMPs formation, increased mean vesicle size and their absolute electronegativity. Proteomic analysis of eMPs identified 1,212 independent proteins, with 68 exclusive to HG and associated with signalling processes related to metabolic processes, oxidation-reduction reactions, hemostasis and thrombosis and cellular interactions at the vascular wall. Compared to eMPs formed under normal conditions, eMPs formed in response to HG possess a ~3-fold greater procoagulant activity, induced a greater production of cellular ROS and were more potent inhibitors of endothelial-dependent relaxation. Conclusions/Interpretation: Taken together our results indicate HG alters the composition of eMPs, making them more potent mediators of endothelial damage. With similar changes in bioactivity being evident in the protein composition and the associated enriched biological processes, eMPs protein content may provide insight into the pathophysiological status of the cells in a hyperglycemic environment and provide use clinically, to identify dysregulated pathways for therapeutic targeting.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/36660 |
| Date | January 2017 |
| Creators | Turner, Maddison |
| Contributors | Kennedy, Christopher Rode, Burger, Dylan |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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