AN-808

To investigate the effects of micro ribonucleic acid (miR)-808 on cardiomyocyte apoptosis and expressions of caspase-3 and caspase-9 in rats with myocardial infarction (MI) by regulating the transforming growth factor-β1 (TGF-β1) signaling pathway.

A total of 24 specific pathogen-free female Sprague-Dawley rats were enrolled and randomly divided into normal group, model group, and miR-808 group, 8 rats in each group. In the model group and miR-808 group, MI model was prepared by ligation of the left anterior descending coronary artery in the rats. The miR-808 group was transfected with miR-808 lentivirus after the model was established. After one week of intervention, the expression of TGF-β1 was detected by reverse transcription-polymerase chain reaction (RT-PCR). The cardiac function of rats was determined by echocardiography. The myocardium of rats was observed by Masson staining. The cardiomyocyte apoptosis of rats was examined by TdT-mediated dUTP-biotin nick end labeling (TUNEL) method. The expression levels of caspase-3 and caspase-9 were detected by Western blotting.

The expression of TGF-β1 mRNA was higher in the model group than that in the normal group (p<0.05), but compared with that in the model group, it was lower in the miR-808 group. The myocardial function and cardiomyocyte survival rate in the miR-808 group was better and higher than those in the model group (p<0.05). The expression levels of caspase-3 and caspase-9 in the miR-808 group were lower than those in the model group (p<0.05).

MiR-808 can inhibit cardiomyocyte apoptosis in rats with MI by down-regulating TGF-β1 expression and inhibiting the expressions of caspase-3 and caspase-9.