Aerobic exercise leads to upregulation of Mir-126 and angiogenic signaling in the heart tissue of diabetic rats

Abstract

ObjectiveMicroRNA-126 plays a critical role in promoting cardiac angiogenesis. Aerobic exercise has also cardioprotective effects by upregulating angiogenic factors. The present study aimed to evaluate the impact of aerobic exercise on cardiac expression of mir-126 and angiogenic signaling pathways. MethodsThirty-two male Wistar rats (180–240 g) were randomly divided into four diabetic control, healthy control, healthy exercise, and diabetic exercise groups. Diabetes was induced by intraperitoneal injection of Streptozotocin (STZ) 50 mg/kg (with citrate buffer) and nicotinamide 110 mg/kg (with saline). Aerobic training groups were performing on a rodent treadmill with an intensity of 25 m/min, 5° gradients, and 30 min each session for 8 weeks. The control groups were placed on a stationary treadmill without training. The heart of the rats was taken and the expression level of cardiac mir-126 was evaluated by Real-time PCR. The protein levels of raf1, spred1, and VEGF were measured using ELISA. Immunohistochemistry was used to measure cardiac muscle capillary density. ResultsThe results showed that diabetes induced by STZ disrupted angiogenesis signaling through the reduction of mir-126, raf1, and VEGF, while an increase in spred1 protein level (p = 0.01 for all). However, 8 weeks of aerobic exercise (in healthy animals) significantly increased mir-126 expression, and raf1 and VEGF proteins (p = 0.05), while significantly decreased spred1 protein (p = 0.05). Also, 8 weeks of exercise training in diabetic rats might improve the cardiac tissue by increasing mir-126 and angiogenic signaling pathways. ConclusionThe results of this study suggest that aerobic exercise training may prevent negative effects of diabetes on heart tissue by improving angiogenic pathway. Therefore, aerobic exercise may be a good strategy for coping with cardiovascular cell damage of diabetes.