[Electroacupuncture improves denervated gastrocnemius atrophy by regulating expression of fork-head protein 3A，muscle atrophy F-box and myogenic differentiation antigen proteins in sciatic nerve injury rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on morphological changes of denervated gastrocnemius(GS) and the expression of fork-head protein(FOXO3A), muscle atrophy F-box(MAFbx)and myogenic differentiation antigen (Myod1) in sciatic nerve injury rats, so as to reveal its mechanism underlying improvement of myoatrophy. METHODS: Eighteen male Sprague-Dawley rats were randomly divided into sham operation, model and EA groups (n＝6 per group). The model of gastrocnemius atrophy was established by crushing the right sciatic nerve. Then, EA (2 Hz) was applied to the right "Zusanli" (ST36) and "Huantiao" (GB30) for 10 min, once a day for 14 successive days. The wet weight of the GS on both sides was weighted to calculate the wet weight ratio (the injured side /the healthy side), and the cross-sectional area (CSA) and diameter of GS fibers were measured after H．E. staining. The expressions of FOXO3A, MAFbx and Myod1 protein and mRNA in the GS tissue were tested using Western blot and fluorescence quantitative PCR, separately. RESULTS: Following modeling, the GS wet weight ratio, CSA and fiber diameter were smaller in the model group than those in the sham group (P<0.01), and were significantly higher in the EA group than in the model group (P<0.01). H．E. staining showed that the GS fibers became smaller and the myocyte got round in the model group, while the GS fibers were bigger and the myocyte was relatively regular in morphology in the EA group. After modeling, the expression levels of FOXO3A, MAFbx and Myod1 mRNA and protein were evidently higher in the model group (P<0.01); Moreover, after EA treatment, modeling-induced increasing of expression levels of FOXO3A and MAFbx mRNA and protein were revised (P<0.01), while the increased expression level of Myod1 was further up-regulated relavant to that in the model group (P<0.01)．. CONCLUSION: EA of ST36 and GB30 can suppress the up-regulated expression of FOXO3A and MAFbx mRNA and protein and further promote the expression of Myod1 mRNA and protein in the GS tissue in rats with denervated GS atrophy, which may contribute to its function in relieving the myoatrophy, promoting the skeletal muscle protein hydrolysis and differentiation of satellite cells.

[Effect of electroacupuncture on muscular atrophy and Slit/Robo signaling in sciatic nerve and lumbar spinal cord tissues in rats with sciatic nerve injury].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Huantiao"(GB30) and" Zusanli"(ST36)on muscular atrophy and expression of Slit-Robo GTPase-activating protein(srGAP)1, 2 and 3 in the injured sciatic nerve and lumbar spinal cord tissues in sciatic nerve injury (SNI) rats, so as to reveal its mechanisms underlying improvement of peripheral nerve injury (PNI)．. METHODS: A total of 120 healthy male SD rats were randomly divided into control, sham-operation, model and EA groups (n＝30 rats in each) which were further divided into 7, 15 and 23 d subgroups (n＝10 rats in each subgroup). The SNI model was established by transecting the right sciatic nerve beneath the piriformis and immediately subsequent end-to-end suture. Rats of the sham operation group received an incision of the corresponding skin and suture. EA (5 Hz/20 Hz, 2－3 mA) was applied to the right GB30 and ST36 for 15 min, once daily, 6 days a week separately for 1，2 and 3 weeks. Rats in the sham-operation and model groups were grasped in the similar procedure as the EA group. The wet weight of gastrocnemius muscles (WWG) on both sides was measured to calculate the recovery rate (weight of the right WWG/weight of the left WWG×100%), and the expression levels of srGAP1, srGAP2 and srGAP3 proteins in the sciatic nerve and the spinal cord (L4-L6) tissues were detected by Western blot. RESULTS: After modeling and compared with the control and sham-operation groups, the recovery rate of WWG was significantly reduced, and the expression levels of srGAP1, srGAP2 and srGAP3 proteins of the sciatic nerve and lumbar spinal cord on day 7, 15 and 23 were considerably increased in the model group (P<0.01). Following the EA treatment, the reco-very rate of WWG was obviously increased and the expression levels of srGAP1, srGAP2 and srGAP3 proteins of both sciatic nerve and spinal cord on day 7, 15 and 23 were further significantly up-regulated in the EA group relevant to the model group (P<0.05，P<0.01). In addition, the expression levels of the 3 proteins in both sciatic nerve and lumbar spinal cord peaked on day 15 and attenuated on day 23. CONCLUSION: EA of GB30 and ST36 may relieve gastrocnemius atrophy in SNI rats, which is related to its function in up-regulating the Slit/Robo signaling in the sciatic nerve and lumbar spinal cord to promote the axonal targeting regeneration and repair of axonal plasma nutrition transportation.

Effect of electroacupuncture on muscular atrophy and Slit/Robo signaling in sciatic nerve and lumbar spinal cord tissues in rats with sciatic nerve injury / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Huantiao"(GB30) and" Zusanli"(ST36)on muscular atrophy and expression of Slit-Robo GTPase-activating protein(srGAP)1, 2 and 3 in the injured sciatic nerve and lumbar spinal cord tissues in sciatic nerve injury (SNI) rats, so as to reveal its mechanisms underlying improvement of peripheral nerve injury (PNI)．. METHODS: A total of 120 healthy male SD rats were randomly divided into control, sham-operation, model and EA groups (n＝30 rats in each) which were further divided into 7, 15 and 23 d subgroups (n＝10 rats in each subgroup). The SNI model was established by transecting the right sciatic nerve beneath the piriformis and immediately subsequent end-to-end suture. Rats of the sham operation group received an incision of the corresponding skin and suture. EA (5 Hz/20 Hz, 2－3 mA) was applied to the right GB30 and ST36 for 15 min, once daily, 6 days a week separately for 1，2 and 3 weeks. Rats in the sham-operation and model groups were grasped in the similar procedure as the EA group. The wet weight of gastrocnemius muscles (WWG) on both sides was measured to calculate the recovery rate (weight of the right WWG/weight of the left WWG×100%), and the expression levels of srGAP1, srGAP2 and srGAP3 proteins in the sciatic nerve and the spinal cord (L4-L6) tissues were detected by Western blot. RESULTS: After modeling and compared with the control and sham-operation groups, the recovery rate of WWG was significantly reduced, and the expression levels of srGAP1, srGAP2 and srGAP3 proteins of the sciatic nerve and lumbar spinal cord on day 7, 15 and 23 were considerably increased in the model group (P<0.01). Following the EA treatment, the reco-very rate of WWG was obviously increased and the expression levels of srGAP1, srGAP2 and srGAP3 proteins of both sciatic nerve and spinal cord on day 7, 15 and 23 were further significantly up-regulated in the EA group relevant to the model group (P<0.05，P<0.01). In addition, the expression levels of the 3 proteins in both sciatic nerve and lumbar spinal cord peaked on day 15 and attenuated on day 23. CONCLUSION: EA of GB30 and ST36 may relieve gastrocnemius atrophy in SNI rats, which is related to its function in up-regulating the Slit/Robo signaling in the sciatic nerve and lumbar spinal cord to promote the axonal targeting regeneration and repair of axonal plasma nutrition transportation.

Molecular insights into mitochondrial dysfunction in cancer-related muscle wasting.

Alterations in muscle mitochondrial bioenergetics during cancer cachexia were previously suggested; however, the underlying mechanisms are not known. So, the goal of this study was to evaluate mitochondrial phospholipid remodeling in cancer-related muscle wasting and its repercussions to respiratory chain activity and fiber susceptibility to apoptosis. An animal model of urothelial carcinoma induced by exposition to N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) and characterized by significant body weight loss due to skeletal muscle mass decrease was used. Morphological evidences of muscle atrophy were associated to decreased respiratory chain activity and increased expression of mitochondrial UCP3, which altogether highlight the lower ability of wasted muscle to produce ATP. Lipidomic analysis of isolated mitochondria revealed a significant decrease of phosphatidic acid, phosphatidylglycerol and cardiolipin in BBN mitochondria, counteracted by increased phosphatidylcholine levels. Besides the impact on membrane fluidity, this phospholipid remodeling seems to justify, at least in part, the lower oxidative phosphorylation activity observed in mitochondria from wasted muscle and their increased susceptibility to apoptosis. Curiously, no evidences of lipid peroxidation were observed but proteins from BBN mitochondria, particularly the metabolic ones, seem more prone to carbonylation with the consequent implications in mitochondria functionality. Overall, data suggest that bladder cancer negatively impacts skeletal muscle activity specifically by affecting mitochondrial phospholipid dynamics and its interaction with proteins, ultimately leading to the dysfunction of this organelle. The regulation of phospholipid biosynthetic pathways might be seen as potential therapeutic targets for the management of cancer-related muscle wasting.