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Expression of Circulating miR-21 and -29 and their Association with Myocardial Fibrosis in Hypertrophic
Andreas Angelopoulos1, Evangelos Oikonomou2, Alexios Antonopoulos1
1Unit for Inherited and Rare Cardiovascular Diseases, 1st Department of Cardiology, Hippokration Hospital, University of Athens Medical School, Athens, Greece.
Insights
Circulating miR-21 levels are elevated in Hypertrophic Cardiomyopathy (HCM) and correlate with myocardial fibrosis extent. This finding may aid in understanding HCM progression and fibrosis.
Area of Science:
- Cardiology
- Molecular Biology
- Biomarkers
Background:
- Hypertrophic Cardiomyopathy (HCM) involves myocardial hypertrophy, fibrosis, and sarcomeric disarray.
- Understanding the molecular mechanisms and biomarkers of HCM is crucial for diagnosis and management.
Purpose of the Study:
- To assess circulating miR-21 and miR-29 expression in HCM patients.
- To investigate the association of these microRNAs with clinical characteristics and myocardial fibrosis.
Main Methods:
- A case-control study included 27 HCM patients, 13 with hypertensive cardiomyopathy, and 10 controls.
- Functional capacity assessed via six-minute walk test; cardiac function by echocardiography.
- Myocardial fibrosis quantified using cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE); microRNA levels measured by qRT-PCR.
Main Results:
- miR-21 levels were significantly higher in HCM and hypertensive cardiomyopathy groups compared to controls (p<0.001).
- miR-29 expression did not differ among the groups.
- In HCM patients, higher miR-21 expression correlated with more extensive myocardial fibrosis (LGE-detected).
Conclusions:
- miR-21 is overexpressed in both HCM and hypertensive cardiomyopathy.
- Elevated miR-21 levels in HCM are associated with the extent of myocardial fibrosis.
Background:
Hypertrophic Cardiomyopathy (HCM) is characterized by myocardial hypertrophy, fibrosis, and sarcomeric disarray.
Objective:
To evaluate the expression levels of circulating miR-21 and -29 in patients with HCM and their association with clinical characteristics and myocardial fibrosis.
Methods:
In this case-control study, 27 subjects with HCM, 13 subjects with hypertensive cardiomyopathy, and 10 control subjects were enrolled. Evaluation of patients' functional capacity was made by the six-minute walk test. Echocardiographic measurements of left ventricle systolic and diastolic function were conducted. Cardiac magnetic resonance late gadolinium enhancement (LGE) -through a semiquantitative evaluation- was used in the assessment of myocardial fibrosis extent in HCM patients. The expression of miR-21 and -29 in peripheral blood samples of all patients was measured via the method of quantitative reverse transcription polymerase chain reaction.
Results:
Circulating levels of miR-21 were higher in both hypertensive and HCM (p<0.001) compared to controls, while expression of miR-29 did not differ between the three studied groups. In patients with HCM and LGE-detected myocardial fibrosis in more than 4 out of 17 myocardial segments, delta CT miR-21 values were lower than in patients with myocardial LGE in 3 or fewer myocardial segments (2.71 ± 1.06 deltaCT vs. 3.50 ± 0.55 deltaCT, p<0.04), indicating the higher expression of circulating miR-21 in patients with more extensive myocardial fibrosis.
Conclusion:
MiR-21 was overexpressed in patients with HCM and hypertensive cardiomyopathy. Importantly, in patients with HCM, more extensive myocardial fibrosis was associated with higher levels of miR-21.
