BioProject

Abstract. The role of platelets in hemostasis and thrombosis is clearly established; however, the mechanisms by which platelets mediate inflammatory and immune pathways are less well understood. More...

Abstract. The role of platelets in hemostasis and thrombosis is clearly established; however, the mechanisms by which platelets mediate inflammatory and immune pathways are less well understood. Platelets interact and modulate the function of blood and vascular cells by releasing bioactive molecules. Although the platelet is anucleate, it contains transcripts that may mirror disease. Platelet mRNA is only associated with low-level protein translation, however, platelets have a unique membrane structure allowing for the passage of small molecules, leading to the possibility that its’ cytoplasmic RNA may be passed to nucleated cells. To examine this question, platelet-like particles with labeled RNA were co-cultured with vascular cells. Co-culture of platelet-like particles with activated THP-1, monocytic, and endothelial cells led to visual and functional RNA transfer. Post-transfer microarray gene expression analysis of THP-1 cells showed an increase in HBG1/HBG2 and HBA1/HBA2 expression which was directly related to the transfer. Infusion of wild-type platelets into a TLR2 deficient mouse model established in vivo confirmation of select platelet RNA transfer to leukocytes. By specifically transferring green fluorescent protein, it was also observed that external RNA was functional in the recipient cells. The observation that platelets possess the capacity to transfer cytosolic RNA suggests a new function for platelets in the regulation of vascular homeostasis. Overall design: THP-1, treated with Pam3CSK4, were co-cultured with platelet-like particles for 12 hours and 24 hours then collected and processed for RNA isolation. We also included as control THP-1 untreated and THP-1 treated with Pam3CSK4. A total of 4 samples were analyzed by microarray for gene expression. Less...