Assessing different noncoding RNAs as markers of platelet reactivity

Abstract Background Antiplatelet therapy (APT) has improved cardiovascular outcomes, but some patients develop thrombosis despite APT. Adjusting APT to platelet reactivity with conventional platelet reactivity tests has proven unsuccessful. Many circulating noncoding RNAs (ncRNAs) are derived from platelets and could serve as novel platelet function markers. Material and methods Platelet reactivity was assessed using light transmission aggregometry (LTA) in the Bruneck 2015 study (N = 338), using the agonists arachidonic acid, adenosine diphosphate, collagen, TRAP-6 amide and U46619. LTA platelet releasates were then used for RT-qPCR of five platelet-enriched microRNAs, three circular RNAs and two long non-coding RNAs. Platelet-poor plasma (PPP) was used as negative control. Results and conclusions Platelet agonists induced aggregation and ncRNA release, with aspirin takers (N = 155) showing lower ncRNA release than individuals not on aspirin (N = 183). Agonist responsiveness differed among ncRNAs, with miR-150 being hyperresponsive to adenosine diphosphate and miR-21 being hyperresponsive to arachidonic acid, whereas other ncRNAs were most strongly released to collagen, suggesting a selective release mechanism. In individuals not on aspirin, the inflammation markers C-reactive protein and granulocyte counts correlated positively with platelet-derived ncRNAs in PPP, while they correlated inversely with platelet-derived ncRNAs in releasates. These correlations were not present in aspirin takers. Higher PPP levels and lower releasate levels of platelet-derived ncRNAs in inflammation suggest platelet exhaustion ex vivo due to platelet pre-activation in vivo. Funding sources British Heart Foundation, VASCage (Centre for Promoting Vascular Health in the Ageing Community) of the Austrian Research Promotion Agency FFG (COMET program - Competence Centers for Excellent Technologies).