MicroRNA: novel regulators involved in the remodeling and reverse remodeling of the heart.

BACKGROUND

MicroRNAs (miRNAs) may serve as potential diagnostic biomarkers and therapeutic targets in cardiovascular research. However, the association between miRNAs and heart remodeling/reverse remodeling has not been evaluated.

METHODS

Lewis rats were divided into three groups: control animals, animals subjected to abdominal aortic constriction (AAC) and those with heterotopic transplantation of abdominal aortic constriction (AAC-HT), respectively. The cardiomyocyte cross-sectional area and changes in the heart cavity were determined. miRNA microarray was used to search for changes in miRNAs during hypertrophy and in the unloading heart, which was also verified using real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR).

RESULTS

The AAC-HT group exhibited a 54% decrease in the cardiomyocyte cross-sectional area compared to the AAC group. In the two test groups, miRNA microarrays revealed changes in 293 miRNAs, among which 40 miRNAs changed >2-fold. Some major changes were also confirmed using qRT-PCR primers. The results indicated that changes in miR-23a and miR-29a were most significant, thus suggesting that these miRNAs may play important roles in heart remodeling and reverse remodeling.

CONCLUSIONS

The changes observed in miRNA expression during hypertrophy and reverse remodeling may indicate possibly meaningful targets for regulating the remodeling or reverse remodeling of the heart.