In her PhD thesis, Simin Jamaly has shown that extracellular vesicles and several micro-RNAs in plasma are linked to venous thromboembolism.

MAIN RESULTS:

1. High plasma levels of P-Selectin Glycoprotein Ligand-1 positive extracellular vesicles are associated with increased risk of venous thromboembolism.
2. Plasma micro-RNA profiling can provide novel biomarkers for venous thromboembolism.
3. A cost-effective modified assay can provide reliable measurements of procoagulant phospholipid activity of extracellular vesicles.

THESIS DEFENCE:

Thesis:  Role of Extracellular Vesicles in the Pathogenesis of Venous Thromboembolism
Candidate: Simin Jamaly
Time: June 13, 2018 at 12:15
Place: UiT The Arctic University of Norway, the MH-building: Large Auditorium
Link to university website (in Norwegian)

SUMMARY:

(1) A micro-RNA profile can indicate high or low risk of venous thromboembolism. A total of nine micro-RNAs were included in the model, and all these micro-RNAs were confined to the extracellular vesicles-depleted plasma fraction. 20 patients with unprovoked venous thromboembolism and 20 age- and sex-matched healthy individuals were included in the study.

(2) Jamaly and co-workers also measured plasma levels of P-Selectin Glycoprotein Ligand-1 positive extracellular vesicles in patients with unprovoked venous thromboembolism. High levels were associated with increased risk. Extracellular vesicles are vesicles with bilayer phospholipid membranes budded off from cells under various conditions.

(3) Mean size of very low-density lipoprotein particles interferes with measurements of extracellular vesicles in the postprandial phase. These results were obtained by analyzing the effect of pre-analytical conditions on plasma concentrations and size distribution of extracellular vesicles.

(4) Finally, the researchers developed a reliable and cost-effective modified assay to measure procoagulant phospholipid activity of extracellular vesicles. The assay will allow for large scale measurements of procoagulant phospholipid activity.

REFERENCES:

(1) Starikova, I., Jamaly, S., Sorrentino, A., Blondal, T., Latysheva, N., Sovershaev, M., & Hansen, J. B. (2015). Differential expression of plasma miRNAs in patients with unprovoked venous thromboembolism and healthy control individuals. Thrombosis research, 136(3), 566-572.

(2) Jamaly, S., Basavaraj, M. G., Starikova, I., Olsen, R., Brækkan, S. K., & Hansen, J. B. (2018). Elevated Plasma Levels of P‐Selectin Glycoprotein Ligand‐1 Positive Microvesicles in Patients with Unprovoked Venous Thromboembolism. Journal of Thrombosis and Haemostasis.

(3) Jamaly, S., Ramberg, C., Olsen, R., Latysheva, N., Webster, P., Sovershaev, T. & Hansen, J.B. Impact of preanalytical conditions on plasma concentration and size distribution of extra cellular vesicles using Nanoparticle Tracking Analysis. (not yet published)

(4) Ramberg, C., Jamaly, S., Latysheva, N., Wilsgaard, L., Basavaraj, M.G., Sovershaev, T. & Hansen, J.B. A readily and robust assay to measure levels of procoagulant (P) activity of negatively charged phospholipids (PL)-a modified clot-based PPL assay. (not yet published)