[MicroRNA-133a antagonizes phenylephrine-induced hypertrophy of neonatal rat cardiomyocytes in vitro].

OBJECTIVE

To investigate the mechanism of miR-133a in reversing neonatal rat cardiomyocyte hypertrophy induced by phenylephrine.

METHODS

A miR-133a precursor cDNA was used to construct an adenovirus vector, which was transfected into 293 cells to harvest miR-133a-containing virus. Neonatal rat cardiac myocytes treated by phenylephrine were exposed to miR-133a adenovirus, and the changes in cell area was measured; the expression levels of miR-133a and Acta1, Actc1, Actb, Myh6, Myh7, and BNP mRNAs were detected by quantitative RT-PCR.

RESULTS

Phenylephrine treatment increased the area of cardiomyocytes by more than 3 folds and significantly enhanced the expression levels of Acta1, Actc1, Actb, Myh6, Myh7 and BNP mRNAs. All these changes were obviously reverse by miR-133a treatment.

CONCLUSION

miR-133a is an important regulator of phenylephrine-induced cardiomyocyte hypertrophy and negatively regulates this process.