ABSTRACT
Objective:To investigate the effects and mechanism of Tuina on denervation-induced atrophy. Methods:A total of 42 Sprague-Dawley rats were randomly divided into sham group (n = 6), model group (n = 18) and Tuina group (n = 18). The model group and Tuina group freed and excised right tibia nerve about one centimeter, while the sham group freed the right tibia nerve only. From the second day after operation, Tuina group accepted Tuina on the injured area, while the sham group and the model group were only fixed without any intervention. Six rats were sacrificed on the 14th, 21st and 28th day after operation in the model and Tuina groups, and the sham group was sacrificed on the 28th day after operation. The gastrocnemius muscles were measured wet weight ratio. The diameter and area of muscle cells were measured under HE staining. The expression of Pax7, MyoD, MyoG, microRNA-1, microRNA-133a and microRNA-206 in the gastrocnemius muscles were detected with reverse transcription real-time quantitative polymerase chain reaction. Results:Compared with the sham group, the wet weight ratio, the area of muscle cells (except the 14-day-Tuina group) and the diameter of muscle cells decreased at each time point in the model group and Tuina group (P < 0.05); compared with the model group, the wet weight ratio, muscle cell diameter and muscle cell area increased at each time point in Tuina group (P < 0.05). Compared with the sham group, the expression of Pax7 increased in the 14-day-model group (P < 0.05) and decreased in the 28-day-model group (P < 0.05), and it increased at each time point (except 28-day) in Tuina group (P < 0.05); compared with the model group, the expression of Pax7 increased at each time point in Tuina group (P < 0.05). Compared with the sham group, the expression of MyoD and MyoG increased at each time point in the model group and Tuina group (P < 0.05); compared with the model group, the expression of MyoD and MyoG increased at each time point (except 14-day) in Tuina group (P < 0.05). Compared with the sham group, the expression of microRNA-1 and microRNA-133a decreased, and microRNA-206 increased in the model group and Tuina group at 21-day (P < 0.05); compared with the model group, the expression of microRNA-1, microRNA-133a and microRNA-206 increased in Tuina group (P < 0.05). Conclusion:Tuina may activate the Pax7/MyoD/MyoG pathway by increasing the expression of muscle-specific microRNA, to promote the proliferation and differentiation of muscle satellite cells, and delay denervation-induced atrophy.
ABSTRACT
Muscle loses normal function after skeletal muscle atrophy that will greatly reduce the quality of personal life. There is no effective way to treat muscle atrophy currently. microRNA (miRNA) as a small molecule of non-coding RNA brings new hope for the treatment of muscular atrophy. The mechanism of miRNA regulating muscle atrophy mainly includes: regulating abnormal muscle protein metabolism by ubiquitin-proteasome system (UPS) and mammalian target of rapamycin pathway (IGF/PI3K/Akt/mTOR), inhibiting abnormal apoptosis of muscle cells by inhibiting the expression of apoptotic factors, promoting muscle regeneration by regulating myogenic factor expression, and promoting angiogenesis by promoting the expression of angiogenic factors, and so on.