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Updated: Apr 16, 2026
Digital PCR for Quantifying Circulating MicroRNAs in Acute Myocardial Infarction and Cardiovascular Disease
Published on: July 3, 2018
MicroRNA profiling of pericardial fluid samples from patients with heart failure
Suvi M Kuosmanen1, Juha Hartikainen2, Mikko Hippeläinen3
1Department of Biotechnology and Molecular Medicine, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.
Aims:
Multicellular organisms maintain vital functions through intercellular communication. Release of extracellular vesicles that carry signals to even distant target organs is one way of accomplishing this communication. MicroRNAs can also be secreted from the cells in exosomes and act as paracrine signalling molecules. In addition, microRNAs have been implicated in the pathogenesis of a large number of diseases, including cardiovascular diseases, and are considered as promising candidate biomarkers due to their relative stability and easy quantification from clinical samples. Pericardial fluid contains hormones secreted by the heart and is known to reflect the cardiac function. In this study, we sought to investigate whether pericardial fluid contains microRNAs and if so, whether they could be used to distinguish between different cardiovascular pathologies and disease stages.
Methods And Results:
Pericardial fluid was collected from heart failure patients during open-heart surgery. MicroRNA profiles of altogether 51 patients were measured by quantitative real-time PCR (qPCR) using Exiqon human panels I and II. On the average, 256 microRNAs were detected per sample, and 70 microRNAs out of 742 profiled microRNAs were detected in every sample. The five most abundant microRNAs in pericardial fluid were miR-21-5p, miR-451a, miR-125b-5p, let-7b-5p and miR-16-5p. No specific signatures for cardiovascular pathologies or clinically assessed heart failure stages could be detected from the profiles and, overall, microRNA profiles of the samples were found to be very similar despite the heterogeneity in the study population.
Conclusion:
Measured microRNA profiles did not separate the samples according to the clinical features of the patients. However, several previously identified heart failure marker microRNAs were detected. The pericardial fluid microRNA profile appeared to be a result of an active and selective secretory process indicating that microRNAs may act as paracrine signalling factors by mediating the local crosstalk between cardiac cells.
Insights
Pericardial fluid contains microRNAs, but their profiles did not distinguish heart failure stages. These microRNAs may mediate local cardiac cell communication.
Area of Science:
- Cardiovascular Biology
- Molecular Biology
- Biomarker Discovery
Background:
- Intercellular communication is vital for multicellular organisms.
- MicroRNAs (miRNAs) secreted in exosomes act as paracrine signaling molecules.
- Cardiovascular diseases involve miRNAs, which are promising biomarkers due to stability.
Purpose of the Study:
- Investigate the presence of miRNAs in pericardial fluid.
- Determine if pericardial fluid miRNAs can differentiate cardiovascular pathologies and disease stages.
Main Methods:
- Collected pericardial fluid from 51 heart failure patients during open-heart surgery.
- Measured miRNA profiles using quantitative real-time PCR (qPCR) with Exiqon human panels.
- Detected an average of 256 miRNAs per sample, with 70 consistently present across all samples.
Main Results:
- Identified the five most abundant miRNAs: miR-21-5p, miR-451a, miR-125b-5p, let-7b-5p, and miR-16-5p.
- No specific miRNA signatures were found to distinguish cardiovascular pathologies or heart failure stages.
- Overall miRNA profiles were highly similar across the diverse patient population.
Conclusions:
- Pericardial fluid miRNA profiles did not correlate with patient clinical features.
- Several known heart failure marker miRNAs were detected in the pericardial fluid.
- The observed miRNA profile suggests an active secretory process, indicating a role in paracrine signaling and local cardiac cell crosstalk.
