About this Research Topic
Platelets participate in a multiple biological processes, such as inflammation, thrombosis and blood clotting where they provide a first and crucial line of defense against vascular injury, thus maintaining normal homeostasis. Recently, platelets were found to contain abundant RNAs and microRNAs (miRNAs) of unknown functionality and clinical relevance, which were regarded as a remnant of platelet biogenesis. However, increasing evidence has shown that platelets can transfer miRNAs to recipient cells and participate in regulating the function of recipient cells. This horizontal transfer of miRNAs may represent a novel form of cell-cell communication, which may be involved in many pathological processes by interacting with many other cells, e.g. endothelial cells, macrophages, hepatocytes, smooth muscle cells and tumor cells. In addition to platelets, microparticles (MPs) can be released from platelets upon activation by physiological agonists, such as collagen, thrombin and ADP, or under various conditions, e.g. diabetes. Recent studies have shown that MPs derived from activated platelets contain miRNAs in complex with the miRNA effector protein Ago2 that might be released into the circulation and engaged in horizontal miRNA transfer to other cells, and those transferred miRNAs can modulate the gene expression and function of the recipient cells. But questions remain to be answered about the specificity and selectivity of this horizontal transfer of miRNAs. Therefore, understanding the mechanism by which platelet interacts with the other cells, and identifying which miRNAs are involved in the horizontal transfer would provide novel therapeutic targets and diagnostic markers for diseases.