Effect of 6 Weeks of Aerobic Training on TGF-Β1, Myostatin and Matrix Metalloproteinase 9 Genes Expression in the Tendon of Fast- and Slow-Twitch Muscles of Male Wistar Rats

Abstract

Background and Aim: Tendon, like the skeletal muscle, exhibits mechanical and morphological adaptations resulted from exercise training; however, little is known about the basic cellular and molecular mechanisms that regulate these responses. The aim of the present study was therefore to investigate the effect of 6 weeks of aerobic training on the TGF-β1, myostatin and MMP9 mRNAs expression in the tendon of fast- and slow-twitch muscles. Methods & Materials For this purpose, 12 male Wistar rats at 8 weeks of age were randomly divided into two groups: experimental (n=6) and control (n=6). The exercise group performed aerobic training for 6 weeks, 5 sessions per week. Forty-eight hours after the last training session, all rats were sacrificed and the tendons of soleus and Extensor Digitorum Longus (EDL) muscles were extracted. Expression of TGF-β1, myostatin and MMP9 mRNAs were assayed using RealTime-PCR. Independent t-test was also used for statistical analysis. Ethical Considerations: All stages of the study were conducted according to the ethical guidelines and authorization of Research Deputy of Islamic Azad University, Central Tehran Branch No. IR.IAU.PS.REC.1398.296. Results: The results showed that the expression of TGF-β1 mRNA in EDL and soleus tendons significantly increased (P≤0.001), whereas the expression of myostatin in EDL tendon was significantly reduced (P≤ 0.001). Increased mRNA expression of MMP9 in the tendon of EDL and soleus muscles was not statistically significant (P>0.05). Conclusion: It seems that aerobic exercise can modulate the expression of genes involved in the regulation of tendon collagen in a muscle type-dependent manner.