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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.
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OBJECTIVE: To observe the effect of electroacupuncture (EA) combined with transplantation of Schwann cells (SCs) on limb locomotor, myelin sheath repair and expression of CD4 and CD8 in compressed spinal cord injury (CSCI) rats, so as to explore its mechanisms underlying improvement of CSCI. METHODS: A total of 45 female SD rats were randomly divided into normal control, model, EA, Schwann cell (SC) transplantation, and EA＋SC transplantation groups (n＝9 rats in each group). The CSCI model was established by laminectomy at T12-L2 and clip compression. Rats of the SC transplantation group accepted injection of the cultured SC suspension (2×106/6 µL) into the central, upper and lower sites of the injured spinal cord (5 mm in depth) 7-8 days after CSCI modeling. EA (2 Hz) was applied to bilateral "Zusanli" (ST36) and "Sanyinjiao" (SP6) for 10 min, once daily and 6 days a week for 3 weeks. The Basso, Beattie and Bresnahan locomotor rating scale (BBB scale) was used to evaluate the function state of CSCI. Morphological changes of the regional injured tissue were observed under light microscope after H．E. staining. The myelin sheath repair state and survival of SCs were detected by Luxol fast blue (LFB) staining and immunofluorescence histochemistry, and the expression of CD4, CD8 and P0 of the injured spinal cord was detected by Western blot. RESULTS: Compared with the normal control group, the BBB scores at the time-points of 0 d, and 1, 2, and 3 weeks were significantly decreased in the model group (P0.05). LFB staining showed a disordered arrangement of the nerve fibers in the white matter, myelinociasis and obvious decrease of the medullated fibers in the model group, and these situations were relatively milder in both EA and SC transplantation groups and obviously milder in the EA＋SC transplantation group. H．E. staining displayed that the structure of the injured region of the spinal cord was incomplete, accompanied with a large number of defect cavities and neuronal karyopyknosis in the model group, while the structure was relatively clear, with an increase of the normal neurons and fewer neuronal karyopyknosis in the EA＋SC transplantation group. Compared with the normal control group, MBP in the model group was significantly decreased (P0.05), while after the intervention and in comparison with the model group, the expression levels of P0 protein were significantly increased in the EA, SC transplantation and EA＋SC transplantation groups (P<0.05), and was significantly higher in the EA＋SC transplantation group than in both EA and SC transplantation groups (P<0.05). The expression levels of CD4 and CD8 proteins were significantly lower in the EA＋SC transplantation group than in the SC transplantation group (P<0.05)．. CONCLUSION: EA＋SCs transplantation can improve the locomotor function in CSCI rats, which may be related to its effects in increasing the survival of transplanted SCs to promote the remyelination and in reducing the immune rejecting reaction.
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@#Objective To explore the effects and mechanism of electroacupuncture(EA)on denervation-induced atrophy. Methods A total of 21 male Sprague-Dawley rats were divided into sham group(n=7),model group(n=7)and EA group (n=7).The latter two groups were cut off their right sciatic nerve.Since one day after modeling,EA group accept-ed electroacupuncture at right Zusanli(ST36)and Huantiao(GB30)for eight weeks.Then,the gastrocnemius of all the rats were obtained,and measured the wet mass ratio.Cross-sectional area(CSA)and fiber diameter were measured after HE staining. The expression of autophagy-related gene ULK1, Atg13, Beclin1, Atg14, Atg7, Atg12,Atg5 and Atg16L1 were tested with reverse transcription real-time quantitative polymerase chain reaction. Results Compared with the sham group,the wet mass ratio,CSA and fiber diameter of gastrocnemius were lower signifi-cantly in the model group and EA group(P<0.001),and they were more in EA group than in the model group(P<0.05).Compared with the sham group,the mRNA expression of ULK1,Atg13,Beclin1,Atg14,Atg7,Atg12,Atg5 and Atg16L1 was more significantly in the model group (P<0.001), and they decreased in EA group compared with those of the model group(P<0.05). Conclusion Electroacupuncture can inhibit the overexpression of autophagy-related gene in denervated rats,which may steady skeletal muscle cells to delay atrophy.
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The skeletal muscle atrophy could be induced by the injury of nerve. According to the source of denervated skeletal mus-cle atrophy, it could be divided into exogenous muscle atrophy and endogenous muscle atrophy. In recent years, the ex-ogenous muscle atrophy models are mainly established by operating, physically injuring or chemically injuring, while the endogenous muscle atrophy models are mainly established by the transgenic animals of amyotrophic lateral sclero-sis. The selection and optimazation of animal models are crucial for the basic studies of denervated skeletal muscle atro-phy.