MicroRNAs (miRNAs) play a key role in the development of heart, and the recent studies have shown that miR-1 and miR-133 are the key regulators of cardiac hypertrophy. Therefore this study aimed to evaluate the effect of an endurance training program on the expression of this miRs and their transcriptional network
In this experimental study. Cardiac hypertrophy was induced by 14 weeks of endurance training (1 hour per day, 6 days per weeks at 75% Vo2max). The rats (221 ± 23 g) of experimental (n=7) and control group (n=7) were anesthetized to evaluate heart morphology changes by echocardiography. After sacrificed the expression of miR-1, miR-133, Hand2, mef2c, HDAC4, and SRF gene expression were evaluated by Real-Time PCR. Finally, the collected data were evaluated by independent t-test to determine of difference between groups.
the echocardiography result approved physiological hypertrophy in experimental group that had undergone endurance training by increase of Left Ventricular Weight (g)/Body Surface Area (LVW/BSA) (p=0.004), LVW (g)/ Body Weight (BW) (kg) (p=0.011), left ventricular diameter end-diastolic (LVDd) (p=0.003) and improve of heart functional indexes such as FS (fractional shortness) (p=0.036), Stroke volume (SV) (p= 0.002). Also the expression of miR-1 (p=0.001) and miR-133 (p=0.004) significantly increased. The expression of SRF, HDAC4, Hand2 genes significantly increased (p< 0.001) in the experimental group compared. While the expression of mef2c did not significantly change.
It seems the expression of miR-1 and miR-133 and their target genes involve in physiological hypertrophy induced by endurance training in the trained rats