Functional prediction of miR-3144-5p in human cardiac myocytes based on transcriptome sequencing and bioinformatics

Whole-Exome Sequencing Reveals Mutational Signature of Hypertrophic Cardiomyopathy

Background

Hypertrophic cardiomyopathy (HCM) is an extremely insidious and lethal disease caused by genetic variation. It has been studied for nearly 70 years since its discovery, but its cause of the disease remains a mystery. This study is aimed to explore the genetic pathogenesis of HCM in order to provide new insight for the diagnosis and treatment of HCM.

Methods

Patients with HCM at 4 hospitals from January 1, 2020, to December 31, 2021, were collected. Peripheral blood of these patients was collected for whole exome sequencing. Moreover, data on the HCM transcriptome were analyzed in the GEO database.

Results

Totally, 14 patients were enrolled, and 6 single-nucleotide variation (SNV) mutant genes represented by MUC12 were observed. Most of the gene mutations in HCM patients were synonymous and non-synonymous, and the types of base mutations were mainly C > T and G > A. Copy number variants (CNVs) predominantly occurred on chromosome 1 in HCM patients. Furthermore, we found that the only ATP2A2 gene was differentially expressed in 3 groups of transcriptome data in GEO database, and the presence of ATP2A2 mutation in 10 samples was observed in this study.

Conclusion

In summary, 7 mutated genes represented by MUC12 and ATP2A2 were found in this study, which may provide novel insights into the pathogenic mechanism of HCM.

A Novel miRNA Screen Identifies miRNA-4454 as a Candidate Biomarker for Ventricular Fibrosis in Patients with Hypertrophic Cardiomyopathy

(1) Background: Left ventricular hypertrophy, myocardial disarray and interstitial fibrosis are the hallmarks of hypertrophic cardiomyopathy (HCM). Access to the myocardium for diagnostic purposes is limited. Circulating biomolecules reflecting the myocardial disease processes could improve the early detection of HCM. Circulating miRNAs have been found to reflect disease processes in several cardiovascular diseases. (2) Methods: We quantified circulating miRNA molecules in the plasma of 24 HCM and 11 healthy controls using the Human v3 miRNA Expression Assay Kit Code set (Nanostring Tech., Seattle, WA, USA) and validated differentially expressed miRNAs using RT-PCR. (3) Results: In comparison to healthy controls, the levels of six miRNAs (miR-1, miR-3144, miR-4454, miR-495-3p, miR-499a-5p and miR-627-3p) were higher in the plasma of HCM patients than healthy individuals (p < 0.05). Of these, higher levels of miR-1, miR-495 and miR-4454 could be validated by real-time PCR. In addition, elevated miR-4454 levels were significantly correlated with cardiac fibrosis, detected by magnetic resonance imaging in HCM patients. (4) Conclusions: Circulating miR-1, miR-495-3p and miR-4454 levels are elevated in the plasma of HCM patients. To the best of our knowledge, this is the first report showing a correlation between miR-4454 levels and cardiac fibrosis in HCM. This suggests miR-4454 as a potential biomarker for fibrosis in these patients.

MiR-875 and miR-3144 switch the human papillomavirus 16 E6/E6* mRNA ratio through the EGFR pathway and a direct targeting effect

By employing bioinformatics scanning approaches and luciferase reporter, our previous study showed that two less common human miRNAs, miR-875 and miR-3144, target a conserved site in the genomes of most high-risk human papillomaviruses (HR-HPVs). In this study, we found that the site targeted by miR-875 and miR-3144 overlapped with the 5' alternative splice site of E6E7 transcripts in HPV16. Using HPV16+ SiHa cells, we showed that high levels of miR-875 and miR-3144 reduced the abundance of unspliced E6, while they promoted three E6* spliced transcripts and decreased the expression levels of E6/E7 oncoproteins and epidermal growth factor receptor (EGFR). A potential miR-875 target site was predicted in EGFR. Meanwhile, depletion of EGFR resulted in a failure to promote E6* but maintained the suppression of unspliced E6 driven by miR-875 and miR-3144. The data suggest that these two miRNAs switch the E6/E6* ratio through both the EGFR pathway and direct targeting. Here, we demonstrate for the first time that human miRNAs regulate the HPV splice isoforms. Furthermore, miRNA-875 and miRNA-3144 are only found in vertebrates and Homo sapiens, and the binding site in EGFR is highly conserved in Boreoeutheria. Our findings highlight the tumour-suppressing effect of miRNAs that possibly appeared in the late stage of biological evolution.

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