Effect of Tuina on Autophagy-related Factor Beclin-1, Vacuolar Protein Sorting and Microtubule-associated Protein Light Chain 3 in Rats with Denervated Skeletal Muscle Atrophy / 中国康复理论与实践

ABSTRACT

Objective:To explore the effect and mechanism of Tuina on denervated skeletal muscle atrophy. Methods:A total of 77 male Sprague-Dawley rats were randomly divided into sham group (n = 7), model group (n = 35) and Tuina group (n = 35). The latter two groups were established skeletal muscle atrophy model by exposing and cutting off the common tibial nerve of rats. One day after modeling, the lower limbs of the surgical side received Tuina in Tuina group. Separately, the surgical side of gastrocnemius muscle were sampled on the 0th, 7th, 14th, 21st and 28thday after modeling, and measured the wet mass ratio. The cross-sectional area and diameter of muscle fiber were measured after HE staining. The mRNA expression of autophagy-realated factor Beclin-1, vacuolar protein sorting (Vps34) and microtubule-associated protein light chain 3 (LC3) were tested with reverse transcription real-time quantitative polymerase chain reaction. Results:There was no statistical difference in the ratio of gastrocnemius wet weight, the cross-sectional area and diameter of muscle fiber, and the mRNA expression of Beclin-1, Vps34 and LC3 among three groups on the 0th day (F < 1.321, P > 0.05). Compared with the sham group, the ratio of gastrocnemius wet weight, the cross-sectional area and diameter of muscle fiber decreased at different time points in the model group and Tuina group (P < 0.05), the ratio of gastrocnemius wet weight was higher, and the cross-sectional area and diameter of muscle fiber were bigger, both except on the 21st day, in Tuina group than in the model group (P < 0.05). Compared with the sham group, the mRNA expression of Beclin-1, Vps34 and LC3 increased at different points in the model group than in Tuina group (P < 0.05), and all the mRNA expression was higher, except on the 14th day, in Tuina group than in the model group (P < 0.05). The ratio of gastrocnemius wet weight, the cross-sectional area and diameter of muscle fiber showed a trend of progressive decrease with time in the model group and Tuina group (P < 0.05). The mRNA expression of Beclin-1 and Vps34 increased (P < 0.05), and the mRNA expression of LC3 increased in the model group 21 days after intervention (P < 0.05). The mRNA expression of Beclin-1, Vps34 and LC3 increased first and then decreased, except the mRNA expression on the 14th day in Tuina group (P < 0.05). Conclusion:Tuina may promote the activation of autophagy by up-regulating the expression of autophagy-realated factor Beclin-1, Vps34 and LC3, remove the damaged organelles and proteins, provide certain synthetic substrate and energy for muscle fiber regeneration, thereby reduce the loss of degree of denervated skeletal muscle atrophy.