Unveiling MiRNA-124 as a biomarker in hypertrophic cardiomyopathy: An innovative approach using machine learning and intelligent data analysis.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a widespread hereditary cardiac pathology characterized by thickened heart walls and rearrangement of cardiomyocytes. Despite extensive research, the mechanisms underlying HCM development remain poorly understood, impeding the development of effective therapeutic and diagnostic strategies. Recent studies have suggested a polygenic nature of HCM development alongside monogenic forms. Transcriptomic profiling is a valuable tool for investigating such diseases. In this study, we propose a novel approach to study regulatory microRNAs (miRNAs) in the context of HCM, utilizing state-of-the-art data analysis tools. METHODS AND RESULTS: Our method involves applying the Monte Carlo simulation and machine learning algorithm to transcriptomic data to generate high-capacity classifiers for HCM. From these classifiers, we extract key genes crucial for their performance, resulting in the identification of 16 key genes. Subsequently, we narrow down the pool of miRNAs by selecting those that may target the greatest number of key genes within the best models. We particularly focused on miR-124-3p, which we validated to have an association with HCM on an independent dataset. Subsequent investigation of its function revealed involvement of miR-124-3p in the RhoA signaling pathway. CONCLUSIONS: In this study we propose a new approach to analyze transcriptomic data to search for microRNAs associated with a disease. Using this approach for transcriptomic profiling data of patients with HCM, we identified miR-124-3p as a potential regulator of the RhoA signaling pathway in the pathogenesis of HCM.

Novel Genes Involved in Hypertrophic Cardiomyopathy: Data of Transcriptome and Methylome Profiling.

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease; its pathogenesis is still being intensively studied to explain the reasons for the significant genetic and phenotypic heterogeneity of the disease. To search for new genes involved in HCM development, we analyzed gene expression profiles coupled with DNA methylation profiles in the hypertrophied myocardia of HCM patients. The transcriptome analysis identified significant differences in the levels of 193 genes, most of which were underexpressed in HCM. The methylome analysis revealed 1755 nominally significant differentially methylated positions (DMPs), mostly hypomethylated in HCM. Based on gene ontology enrichment analysis, the majority of biological processes, overrepresented by both differentially expressed genes (DEGs) and DMP-containing genes, are involved in the regulation of locomotion and muscle structure development. The intersection of 193 DEGs and 978 DMP-containing genes pinpointed eight common genes, the expressions of which correlated with the methylation levels of the neighboring DMPs. Half of these genes (AUTS2, BRSK2, PRRT1, and SLC17A7), regulated by the mechanism of DNA methylation, were underexpressed in HCM and were involved in neurogenesis and synapse functioning. Our data, suggesting the involvement of innervation-associated genes in HCM, provide additional insights into disease pathogenesis and expand the field of further research.

Regulation of SMAD Signaling Pathway by miRNAs Associated with Myocardial Fibrosis: In silico Analysis of Target Gene Networks.

Hypertrophic cardiomyopathy (HCM) is a hereditary heart disease caused by mutations in the sarcomere genes, which is accompanied by myocardial fibrosis leading to progressive heart failure and arrhythmias. Recent studies suggest that the HCM development involves dysregulation of gene expression. Among the molecules involved in this process are microRNAs (miRNAs), which are short non-coding RNAs. Typically, one miRNA regulates several target genes post-transcriptionally, hence, it might be difficult to determine the role of a particular miRNA in the disease pathogenesis. In this study, using the PubMed database, we selected 15 miRNAs whose expression is associated with myocardial fibrosis, one of the critical pathological processes in HCM. We then used an earlier developed algorithm to search in silico for the signaling pathways regulated by these miRNAs and found that ten of them participate in the regulation of the TGF-ß/SMAD signaling pathway. At the same time, among the SMAD signaling pathway genes, the target of the most identified miRNAs was the MYC gene, which is involved in the development of fibrosis in some tissues. In our earlier work, we found that the TGF-ß/SMAD pathway is also regulated by a set of other miRNAs associated with the myocardial hypertrophy in HCM. The fact that two sets of miRNAs identified in two independent bioinformatic studies are involved in the regulation of the same signaling pathway indicates that the SMAD signaling cascade is indeed a key element in the regulation of pathological processes in HCM. The obtained data might contribute to understanding pathological processes underlying HCM development.

Circulating miR-499a-5p Is a Potential Biomarker of MYH7-Associated Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is the most common inherited myocardial disease with significant genetic and phenotypic heterogeneity. To search for novel biomarkers, which could increase the accuracy of HCM diagnosis and improve understanding of its phenotype formation, we analyzed the levels of circulating miRNAs­stable non-coding RNAs involved in post-transcriptional gene regulation. Performed high throughput sequencing of miRNAs in plasma of HCM patients and controls pinpointed miR-499a-5p as one of 35 miRNAs dysregulated in HCM. Further investigation on enlarged groups of individuals showed that its level was higher in carriers of pathogenic/likely pathogenic (P/LP) variants in MYH7 gene compared to controls (fold change, FC = 8.9; p < 0.0001). Just as important, carriers of variants in MYH7 gene were defined with higher miRNA levels than carriers of variants in the MYBPC3 gene (FC = 14.1; p = 0.0003) and other patients (FC = 4.1; p = 0.0008). The receiver operating characteristic analysis analysis showed the ability of miR-499a-5p to identify MYH7 variant carriers with the HCM phenotype with area under the curve value of 0.95 (95% confidence interval: 0.88−1.03, p = 0.0004); sensitivity and specificity were 0.86 and 0.91 (cut-off = 0.0014). Therefore, miR-499a-5p could serve as a circulating biomarker of HCM, caused by P/LP variants in MYH7 gene.