PB0787 - Role of selected microRNAs in regulation of hemostasis in zebrafish larvae

Monday, June 24, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Co-Author(s)

PC

Paulina Ciepla

Post-doc
University of Geneva
Geneva, Geneve, Switzerland
RF

Richard J. Fish

Senior Research Associate
University of Geneva
Geneva, Geneve, Switzerland
SN

Séverine Nolli

Lab technician
University of Geneva
Geneva, Geneve, Switzerland
SD

Sylvie Dunoyer-Geindre

Scientific collaborator
University of Geneva
Geneva, Geneve, Switzerland
JC

Julia Charlon

PhD Student
University of Geneva
Geneva, Geneve, Switzerland
JR

Jean-Luc Reny

Professor
Division of General Internal Medicine, Geneva University Hospitals
Geneva, Geneve, Switzerland
MN

Marguerite Neerman-Arbez

Professor
University of Geneva
Geneva, Geneve, Switzerland

Presenting Author(s)

Pierre Fontana

Professor
Division of Angiology and Hemostasis, Geneva University Hospitals
Genève, Geneve, Switzerland

Background: Thrombosis is the main consequence of cardiovascular diseases and antiplatelet drugs are a cornerstone for the prevention of recurrence of these events. However, the biological impact of these drugs on platelet reactivity is variable in patients, leading to possibility of developing thrombotic or bleeding events. This results from our poor understanding of factors regulating thrombocyte function. Several microRNAs (miRNAs) have been associated with platelet reactivity, making them promising candidates for biomarkers of cardiovascular events. However, the mechanism of miRNA-mediated regulation of thrombocyte function remains enigmatic.

Aims: We proposed to functionally validate miR-96, miR-150 and miR-223 as potential biomarkers of platelet function. These miRNAs are abundant in human platelets and were associated with platelet reactivity in multiple clinical and/or animal studies.

Methods: We developed a zebrafish model based on the real-time, in vivo monitoring of thrombus formation upon laser-induced blood vessel injury in larvae. Furthermore, the transgenic zebrafish lines overexpressing miR-96, miR-150 and miR-223 specifically in thrombocytes were generated and validated.

Results: The miR-96 and miR-150 manipulations resulted in decreased number of thrombocytes in the forming thrombus after the venous laser injury. Similar results were observed in the artery but only in the miR-96-overexpressing fish. The miR-223 manipulations did not significantly affect the size of venous thrombus after the injury, however, led to a decrease in the time to first cells adhesion to the injured tissue.

Conclusion(s): The elevated level of each of these miRNAs led to widely different characteristic of the forming thrombus and thrombocytes’ properties in our assay. This is in line with a major role of miRNAs in platelet reactivity and thrombus formation. Currently, we are working on determining specific genes and biological pathways targeted by these miRNAs that lead to the phenotypic changes in cellular behaviour.