Effect and mechanism of exercise-induced miR-222 in the protection of myocardial damage in diabetic mice / 中华内分泌代谢杂志

ABSTRACT

Objective To investigate the protective effects of aerobic exercise and miR-222 expression in myocardium of diabetic mice. Methods C57BL/ 6 mice were divided into 4 groups normal non-exercise group (SC), normal exercise group(EC), non-exercise diabetic group(SD), and exercise diabetic group(ED). After the diabetic model was established successfully, EC and ED underwent a swimming training for 5 weeks. By the end of the experiment, light microscope was used to observe the pathological changes of heart, RT-PCR for myocardial miR-222 expression, and Western blot for phosphatase and tensin homolog deleted on chromosome ten ( PTEN ), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (Akt) protein expressions in myocardial tissue. Results (1) Under the light microscope, the diabetic mice had a significant change in myocardial structure, with great disorder in the cell arrangement. After exercise intervention, the lesion was alleviated. (2) MiR-222 expression was increased in the myocardium of normal mice and DM mice after exercise (all P<0. 05); (3) Compared with SC group, PTEN expression was increased and PI3K/ Akt expressions were inhibited in myocardium of diabetic mice(all P <0. 05). After exercise intervention, the expression of PTEN reduced( P < 0. 05) and PI3K/ Akt pathway was reactivated in myocardium of diabetic mice (all P<0. 05). Conclusion Exercise intervention may protect the myocardium under high glucose via inducing miR-222 and activating PI3K/ Akt signaling pathway.