Circular RNA expression profiles of persistent atrial fibrillation in patients with rheumatic heart disease

Abstract

Objective: To investigate the expression profile of circular RNAs (circRNAs) and proposed circRNA-microRNA (miRNA) regulatory network in atrial fibrillation (AF).

Methods: Atrial tissues from patients with persistent AF with rheumatic heart disease and non-AF myocardium with normal hearts were collected for circRNA differential expression analyses by high-throughput sequencing. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to predict the potential functions of the differentially expressed genes and AF-related pathways. Co-expression networks of circRNA-miRNA were constructed based on the correlation analyses between the differentially expressed RNAs. Quantitative reverse transcription polymerase chain reaction (PCR) was performed to validate the results.

Results: A total of 108 circRNAs were found to be differentially expressed in AF. Among them, 51 were up-regulated, and 57 were down-regulated. Dysregulated circRNAs were validated by quantitative real-time PCR. The GO and KEGG pathway enrichment analyses were executed to determine the principal functions of the significantly deregulated genes. Furthermore, we constructed correlated expression networks between circRNAs and miRNAs. circRNA19591, circRNA19596, and circRNA16175 interacted with 36, 28, and 18 miRNAs, respectively; miR-29b-1-5p and miR-29b-2-5p were related to 12 down-regulated circRNAs, respectively.

Conclusion: Our findings provide a novel perspective on circRNAs involved in AF due to rheumatic heart disease and establish the foundation for future research of the potential roles of circRNAs in AF.

Figure 1

Volcano plot of circRNAs between AF and controls. Green plots represent down-regulated circRNAs. Red plots represent up-regulated circRNAs with absolute |log2 Fold Change| >1.0 and corrected P-value <0.05. Gray plots represent circRNAs with no significant difference. Blue plots represent circRNAs with |log2 Fold Change| >1.0 but with no significant difference

Figure 2

Comparison of circRNA expression levels between sequencing and qRT-PCR results. The Y-axis of the columns in the chart represents the log2-transformed fold changes computed from the sequencing and qRT-PCR data

Figure 3

GO enrichment analysis for dysregulated circRNA gene symbols. Most significantly enriched [−log10 (p-value)] GO terms of circRNA gene symbols according to biological process (red bar), cellular component (green bar), and molecular function (blue bar)

Figure 4

KEGG pathway enrichment analysis of up- and down-regulated circRNAs with the top five enrichment score

Figure 5

circRNA–miRNA regulatory network analysis of ncRNAs in patients with AF. Red diamonds represent up-regulated circRNAs. Green diamonds represent down-regulated circRNAs. Blue dots represent miRNA