Screening and identification of microRNA involved in unstable angina using gene-chip analysis

Abstract

Increasing evidence has suggested that microRNA (miRNA) may play a role in the pathogenesis of cardiovascular disease, which has led to a greater understanding of the complex pathophysiological processes underlying unstable angina (UA). The present study aimed to investigate changes in the miRNA expression profiles of patients with UA using gene-chip analysis, in order to further elucidate the pathogenesis of UA. Total RNA was extracted and purified from plasma samples collected from patients with UA and healthy controls. The samples underwent microarray analysis using an Exiqon miRCURY LNA™ microRNA Array. Differentially expressed miRNAs were identified by volcano plot filtering, and were validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). In addition, functional annotation of the differentially expressed miRNAs involved gene ontology analyses. Among the 212 miRNAs differentially expressed between the two groups, 82 were upregulated and 130 were downregulated. Notably, the results of the RT-qPCR were consistent with the gene-chip results. The miRNAs identified in the present study may be potential novel biomarkers for the prevention and early diagnosis of UA. Furthermore, the results of the present study suggested that UA occurs as a result of complex and dynamic processes regulated by numerous factors, including multiple miRNAs.

Keywords: gene chip; microRNA; reverse transcription-quantitative polymerase chain reaction; unstable angina.

Figure 1.

RNA electrophoresis on a denaturing agarose gel. A sharp distinction is evident at the small site of the 18S and 28S ribosomal RNA bands/peaks in total RNA electrophoresis. 1: control group; 2: UA group.

Figure 2.

Gene-chip results were verified by RT-qPCR. Gene expression levels were normalized to the glyceraldehyde-3-phosphate dehydrogenase reference gene. RT-qPCR analysis demonstrated that the change tendency of the expression of miR-183-3p, miR-9-3p, miR-138-5p, miR-204-3p and miR-124-3p was consistent with the microarray data. miR, microRNA; RT-qPCR, reverse transcription-quantitative polymerase chain reaction.