The Effect of 6 Weeks of Endurance Training on Gene Expression of GSK-3β in the Motor Area of the Spinal Cord of Male Wistar Rats with Diabetic Neuropathy

Glycogen synthase kinase 3 beta is a regulator key of many signaling pathways. It is reported that inhibition of this kinase increases neuronal survival. Accordingly, in this study, the effect of 6 weeks of endurance training on the gene expression of GSK-3β in the motor area of the spinal cord of male Wistar rats with diabetic neuropathy was investigated. For this aim, 16 male Wistar rats were randomly assigned to four groups: healthy control, healthy trained, neuropathy control, neuropathy trained. Intraperitoneal injection of a STZ (streptozotocin) solution (45 mg/kg) was used to induce diabetes. 2 weeks after STZ injection, the mechanical allodynia and thermal hyperalgesia tests demonstrated the diabetic neuropathy. A moderate endurance training protocol was performed for 6 weeks. 24 hours after the last training session, the rats were sacrificed and the L4-L6 motor neurons of the spinal cord tissue were removed. GSK-3β mRNA expression was performed using Real Time-PCR. Statistical analysis showed that neuropathy trained group experienced a decrease in the GSK-3β expression compared with neuropathy control group (P=0.02). On the other hand, there was a significant difference between healthy control and neuropathy control groups (P=0.02), that is to say the gene expression increased in neuropathy control group. However, there was no significant difference between healthy control and neuropathy trained groups. The results show that one of the factors involved in the spread of damage to motor neurons of diabetic neuropathy is incremental regulation of mRNAGSK-3β and training as a non-pharmacotherapy strategy can modulate and return it to normal levels. Therefore, it is suggested that GSK-3β should receive attention as a novel treatment target in diabetes.