Abstract:

BACKGROUND: Protein degradation is a key link in delaying amyotrophy. The expressions of muscle ring finger protein (Murf1) and nuclear factor κB (NF-κB) are increased in amyotrophy, and studies have been demonstrated that passive movement can suppress the occurrence of amyotrophy.
OBJECTIVE: To investigate expression pattern of Murf1 and NF-κB during denervated amyotrophy. at different time points, and to explore effects of passive movement on the expression of Murf1 and NF-κB in denervated amyotrophy.
METHODS: Sciatic nerves of rats were cut down in the denervated and passive movement groups. Sham operation was performed in the sham-operated group. Rats in the passive movement group were performed passive movement (45° traction and full range flexion) at 1 day after operation, twice per day, 300 frequency per time. The expressions of Murf1 and NF-κB were determined by RT-PCR and Western blot at 2, 14 and 28 days after intervention.
RESULTS AND CONCLUSION: Compared with the sham-operated group, the expressions of Murf1, NF-κB mRNA and protein in the denervated group were obviously increased at each time points (P < 0.05). Compared with the denervation group, the expressions of Murf1, NF-κB mRNA in the passive movement group were dramatically decreased (P < 0.01). The muscle wet weight was obviously decreased after denervation, which was greater in the positive movement group than that of the denervation group at 14 days (P < 0.05). The expression of mRNA and protein of Murf1 and NF-κB were negatively correlated to muscle wet weight in the denervated group (r = -0.795, P < 0.01; r = -0.834, P < 0.01). Passive movement can prevent amyotrophy by reducing the expressions of Murf1 and NF-κB.