earticle

영어

The present study investigated whether treadmill exercise with bone marrow stromal cells (BMSCs) transplantation increase expression lev-el of protein synthesis-related molecules in the soleus muscle after spi-nal cord injury (SCI). The spinal cord contusion injury was performed at the T9–10 level using the impactor (10 g×25 mm). BMSCs were cultured from femur and tibia of 4-week-old rats and then transplanted directly into the lesion 1-week post injury. The rats in exercise group were walk-ing on treadmill device for 6 days per a week during 6 weeks. Prepared soleus muscles were used for examining mechanisms of protein syn-thesis after SCI. Myostatin induction level was increased by SCI, but BMSCs engrafting after SCI decreased compared to SCI group. Combi-nation of treadmill exercise with BMSCs showed more potent decre-ment on myostatin expression. Protein kinase B (Akt) and mammalian target of rapamycin (mTOR) levels were significantly increased in SCI and BMSCs transplantation group compared to SCI group. Combination of treadmill exercise with BMSCs further facilitated expression levels of Akt and mTOR. Insulin-like growth factor-I (IGF-I) and phosphorylated cyclic adenosine monophosphate response element-binding protein (p-CREB) induction levels were more increased in SCI and BMSC trans-plantation group compared to SCI group. Combination of treadmill exer-cise with BMSCs further increased expression levels of IGF-I and p-CREB, although statistical significance was not appeared. Combining treadmill exercise with BMSCs transplantation might accelerate protein synthesis and hypertrophy in the soleus muscle after SCI through acti-vation of IGF-I/mTOR signaling pathway.