Effects of High-Intensity Interval Training (HIIT) on miR-29c and miR-146a expression in the hippocampus of streptozotocin-induced diabetic rats

Abstract

Background

MicroRNAs like miR-146a and miR-29c are potential biomarkers for diabetes, which is linked to brain impairments such as cognitive decline and hippocampal dysfunction due to hyperglycemia and inflammation. This study investigates the effects of high-intensity interval training (HIIT) on hippocampal miR-146a and miR-29c expression and serum TNF-α levels in diabetic rats, highlighting its role in reducing inflammation and improving brain function.

Methods

Twenty-four male Wistar rats were divided into four groups: Control (Normal), 1-week diabetes (Diabetes 1 W), 6-week diabetes (Diabetes 6 W), and diabetic HIIT (Diabetes-Exe). Diabetes was induced using streptozotocin (55 mg/kg) and rats with blood glucose > 250 mg/dL were included. HIIT was conducted for six weeks, and hippocampal miR-146a, miR-29c expression, and TNF-α serum levels were assessed using Real-Time PCR and ELISA. TNF-α serum levels were measured as a marker of systemic inflammation.

Results

Diabetic rats exhibited decreased miR-146a and increased miR-29c expression in the hippocampus compared to controls. Additionally, TNF-α serum levels were significantly higher in the diabetic groups, indicating an elevated inflammatory state. HIIT in the Diabetes-Exe group resulted in a non-significant change in miR-29c expression and TNF-α serum levels, accompanied by a significant increase in miR-146a expression compared to the Diabetes 6 W group.

Conclusion

HIIT exercise may help reduce hippocampal neuronal damage in diabetic rats by modulating miR-146a expression, improving blood glucose control, and reducing inflammation. Although HIIT did not significantly alter miR-29c expression, its potential as an effective non-pharmacological strategy for managing diabetic neuropathy complications cannot be excluded.