MicroRNAs, innate immunity and ventricular rupture in human myocardial infarction
Nina Zidar1, Emanuela Boštjančič, Damjan Glavač
1Institute of Pathology, University of Ljubljana, Slovenia. nina.zidar@mf.uni-lj.si
Abstract:
MicroRNAs are non-coding RNAs, functionioning as post-transcriptional regulators of gene expression. Some microRNAs have been demonstrated to play a role in regulation of innate immunity. After myocardial infarction (MI), innate immunity is activated leading to an acute inflammatory reaction. There is evidence that an intense inflammatory reaction might contribute to the development of ventricular rupture (VR) after MI. Using real-time PCR, we analysed the expression of miR-146a, miR-150, and miR-155 in autopsy samples of infarcted heart tissue from 50 patients with MI (23 with VR and 27 without VR). An altered expression of all three microRNAs was found in MI compared to the normal hearts. Comparing MI patients with VR and those without VR, we found miR-146a up-regulation, and miR-150 and miR-155 down-regulation in patients with VR. In conclusion, our study demonstrated an altered expression of miR-146a, miR-150, and miR-155 in MI compared to the normal hearts. These microRNAs are involved in regulation of the innate immunity. Differential expression of these microRNAs in MI patients with VR in comparison to those without VR provides further evidence that innate immunity resulting in an intense inflammatory reaction plays an important role in the pathogenesis of VR after MI in humans.
Insights
Altered microRNA expression, including miR-146a, miR-150, and miR-155, is linked to myocardial infarction (MI) and ventricular rupture (VR). These microRNAs regulate innate immunity, suggesting a role in post-MI inflammation and VR pathogenesis.
Area of Science:
- Cardiology
- Molecular Biology
- Immunology
Background:
- MicroRNAs (miRNAs) are key post-transcriptional regulators of gene expression.
- Innate immunity activation and inflammation are critical after myocardial infarction (MI).
- Intense inflammation post-MI may contribute to ventricular rupture (VR).
Purpose of the Study:
- To investigate the expression of specific microRNAs (miR-146a, miR-150, miR-155) in myocardial infarction (MI).
- To compare microRNA expression between MI patients with and without ventricular rupture (VR).
- To explore the role of these microRNAs in innate immunity and VR pathogenesis.
Main Methods:
- Real-time PCR was used to analyze miRNA expression.
- Autopsy samples of infarcted heart tissue from 50 MI patients were studied.
- Patients were categorized into groups with and without VR.
Main Results:
- All three studied microRNAs (miR-146a, miR-150, miR-155) showed altered expression in MI compared to normal hearts.
- MI patients with VR exhibited up-regulation of miR-146a.
- MI patients with VR showed down-regulation of miR-150 and miR-155 compared to those without VR.
Conclusions:
- Altered expression of miR-146a, miR-150, and miR-155 occurs in MI.
- These miRNAs are involved in innate immunity regulation.
- Differential expression patterns in VR patients suggest a role in VR pathogenesis via inflammation.
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