The Effect of Hind Limb Immobilization on Expression of Some Genes Involved in the Regulation of Mitochondrial Processes in Soleus Muscle of Trained and Untrained Rats

Abstract

Background and Aim: The purpose of this study was to determine the effect of a hind limb immobilization on the expression of PGC-1α, NRF1, Mfn2, PINK1 and Drp1 genes as the main regulators of mitochondrial quality and function in soleus muscle of endurance trained rats. Materials and Methods: In this study, 15 male Sprague-Dawley rats were divided into three groups (control, exercise +immobilization and immobilization). The exercise + immobilization group run on the treadmill for 12 weeks and five times per week. The hind limb of the animal was immobilized for seven days with the casting method. Soleus muscle was extracted and the expression of the genes was measured by RT-PCR method. Univariate ANOVA and Tukey post hoc test were used to determine the differences (α = 0.05). Ethical Considerations: This study with research ethics code IR.SUMS.REC.1396.S444 has been approved by research ethics committee at Shiraz university of medical sciences, Iran. Findings: Results showed that immobilization in both immobilization and exercise +immobilization groups, compared to the conterl group, reduced the expression of PGC-1α gene (p = 0.001 and p = 0.045), NRF1 (p = 0.001 and p = 0.006), Mfn2 (p = 0.001, p = 0.001) and increased the expression of PINK1 (p = 0.001 and p= 0.001), but the expression of Drp1 gene didn't change significantly (p = 0.069 and p = 0.223). Also, studies showed that the expression of PGC-1α (p = 0.013), NRF1 (p = 0.001) and Mfn2 (p = 0.001) in the exercise + immobilization was lower in compare with the immobilization group. The expression of PINK1 was lower than immobilization group as well (p = 0.001). Conclusion: This study shows that endurance training has a protective effect on mitochondrial quality during the immobilization period, but it can't prevent mitochondrial dysfunction