Effects of miR-26a-5p and PTEN on Myocardium of Myocardial Ischemia-reperfusion Mice

Abstract

This study aimed to investigate the effects of miR-26a-5p and PTEN on myocardium of myocardial ischemia-reperfusion mice. Twelve C57/B6 male mice were randomly selected and divided into control group and mouse model group with 6 mice in each group, in which no surgical modeling was normally performed. Mice were killed 2 hours after operation to collect myocardial tissue. H9C2 was transfected with miR-26a-5p-mimic and blank vector to overexpress miR-26a-5p, and then normal group, hypoxia/reoxygenation group (cell model group), blank group and overexpression group were established respectively. Protein expressions of PTEN, Caspase-3, Caspase-9, P13K and p-Akt in tissues and cells of mice were detected. Expressions of miR-26a-5p and PTEN in myocardial tissue and cells of mice were detected. Apoptosis was detected. The relationship between miR-26a-5p and PTEN was determined. Expressions of miR-26a-5p in tissues of mouse model group were lower than those of normal group, while PTEN expressions were opposite (p<0.05). Expressions of miR-126 in overexpression group were increased compared with those of cell model group and blank group, and decreased compared with those of control group (P<0.05). Expressions of PTEN in overexpression group were lower than those in cell model group and blank group, and higher than those in control group (p<0.05). Compared with control group, miR-26a-5p was decreased and PTEN was increased in cell model group (P<0.05). Compared with blank group and cell model group, expressions of PTEN, Caspase-3 and Caspase-9 proteins in overexpression group were significantly decreased, while expressions of P13K and p-Akt proteins were significantly increased (p<0.05). Apoptosis rate in overexpression group was significantly lower than that in cell model group and blank group (p<0.05). Dual-luciferase reporter proved that there was a targeted regulatory relationship between miR-26a-5p and PTEN. In conclusion, up-regulation of miR-26a-5p regulates PTEN/PI3K/p-Akt signaling pathway and reduces myocardial cell apoptosis, thus improving ischemia-reperfusion injury.