Circulating MicroRNAs as Novel Biomarkers for Platelet Activation
Rationale: MicroRNA biomarkers are attracting considerable interest. Effects of medication, however, have not been investigated thus far.
Objective: To analyse changes in plasma microRNAs in response to anti-platelet therapy.
Methods and Results: Profiling for 377 microRNAs was performed in platelets, platelet microparticles, platelet-rich plasma, platelet-poor plasma and serum. Platelet-rich plasma showed markedly higher levels of microRNAs than serum and platelet-poor plasma. Few abundant platelet microRNAs, such as miR-24, miR-197, miR-191, and miR-223, were also increased in serum compared to platelet-poor plasma. In contrast, anti-platelet therapy significantly reduced microRNA levels. Using custom-made qPCR plates, 92 microRNAs were assessed in a dose-escalation study in healthy volunteers at four different time points: at baseline without therapy, at 1 week with 10mg prasugrel, at 2 weeks with 10mg prasugrel+75mg aspirin and at 3 weeks with 10mg prasugrel+300mg aspirin. Findings in healthy volunteers were confirmed by individual TaqMan qPCR assays (n=9). Validation was performed in an independent cohort of patients with symptomatic atherosclerosis (n=33) who received low dose aspirin at baseline. Plasma levels of platelet microRNAs, such as miR-223, miR-191 and others, i.e. miR-126 and miR-150, decreased upon further platelet inhibition.
Conclusions: Our study demonstrated a substantial platelet contribution to the circulating microRNA pool and identified microRNAs responsive to anti-platelet therapy. It also highlights that anti-platelet therapy and preparation of blood samples could be confounding factors in case-control studies relating plasma microRNAs to cardiovascular disease.
- Received November 14, 2012.
- Revision received December 21, 2012.
- Accepted December 28, 2012.
- Copyright © 2013, Circulation Research