The effect of 6 weeks of high intensity interval training (HIIT) on expression of mirRNA29-c and mirRNA146-a in the hippocampus of streptozotocin- induced diabetic male rats

Abstract Background/objectives: MicroRNAs have been reported as potentially useful biomarkers for various diseases, including diabetes, heart diseases, and neurological diseases. The aim of this study was to assess whether microRNA-146a and its inflammatory mediator (TNF-a) and microRNA-29c may be changed in the hippocampus of streptozotocin-induced diabetic rats, after a period of high – intensity interval training. Methods Twenty-four male Wistar rats (180 ± 10 g, 8–10 weeks age) were assigned to 4 groups: control (C), diabetes (D-1w), diabetes (D-6w), and diabetes high-intensity interval training (DHIIT). Diabetes induced by the single-dose injection of streptozotocin (STZ; 55 mg/kg dissolved in 0.1 M of citrate buffer; pH 4.5; i.p.) in 12-h fasted and blood sugar higher than 250 was considered diabetic. The effects of six weeks of HIIT on hippocampus microRNA-146a, microRNA-29c, as well as evaluation of tumor necrosis factor-alpha (TNF-α ) in serum were evaluated using Real-Time PCR and ELISA techniques respectively. Results The results indicated a reduction in expression of miR-146a and an increase in expression of microRNA-29c genes in the hippocampus of diabetic rats compared to control. Also TNFα increased in the D groups in comparison with C group. However, HIIT training in DHIIT significantly decreased the microRNA-29c and TNFα and increased microRNA-146a expression in comparison of D-6w group. Conclusion Our results implied that increased hyperglycemia and inflammation status were associated with brain impairment in DM rats, which were negatively correlated with miR-146a and microRNA-29c expression. It seems that HIIT training improves hypoglycemic and inflammatory conditions in diabetic rats.