Effect Of Tuina On Autophagy-related Factor In Rats With Denervated Skeletal Muscle Atrophy

Objective To investigate the effects of Tuina on the expression of autophagy-related factors Beclin-1,vacuolar sorting protein 34（Vps34） and microtubule-associated protein light chain 3（LC3） in rats with denervated skeletal muscle atrophy,and to explore the possible mechanism of Tuina to maintain the stability of the intracellular environment and delay the process of 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,and sham group only exposed tibial nerve but not cut off.One day after modeling,the lower limbs of the surgical side received Tuina in Tuina group,15 minutes each time,once a day,and the other two groups were fixed only,not treated.Separately,the surgical side of gastrocnemius muscle were sampled on the 0^th,7^th,14^th,21^st,28^th d 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,Vps34 and 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 the muscle fiber,and the mRNA expression of Beclin-1,Vps34 and LC3 among three groups in the 0^th day（P>0.05）.Compared with the sham group,the ratio of gastrocnemius wet weight,the cross-sectional area and diameter of the muscle fiber decreased in different time points in the model group and Tuina group（P<0.05）,and the ratio of gastrocnemius wet weight were higher,both except on the 21^st day,and the cross-sectional area and diameter of the muscle fiber were bigger,both except on the 7^th 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 in different time in the model group and Tuina group（P<0.05）,and the mRNA expression of Beclin-1 and LC3 were higher,except on the 14^th day,and the mRNA expression of Vps34 were higher in the 7^th day and 21^st 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 the 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 after 21^st day（P<0.05）,and the mRNA expression of LC3increased at 21^st day in the model group（P<0.05）.The mRNA expression of Beclin-1,Vps34 and LC3 increased first and then decreased,except the mRNA expression of Vps34 and LC3 on the 14（th） day in Tuina group（P<0.05）.Conclusion Tuina can up-regulate the expression of autophagy-related factors Beclin-1,Vps34 and LC3 mRNA in rats with denervated skeletal muscle atrophy,suggesting that Tuina may promote the activation of autophagy,clear the damaged organelles and proteins,stabilize the intracellular environment,and provide certain synthetic substrate and energy for muscle fiber regeneration,which delays the process of denervated skeletal muscle atrophy while reducing the degree of muscle atrophy.