The expression of NF-κB p65 in atrophic muscle and the effect of passive movement on its change

Abstract

Objective To investigate the role of nuclear factor kappa B (NF-κB) p65 in skeletal muscle denervation atrophy in rats and the effect of passive movement on its expression and explore the molecular mechanism of denervation muscle atrophy and its prevention. Methods Forty two Wistar rats were randomly divided into 3 groups: denervation group ( n = 18), passive movement group ( n = 18) and control group ( n =6). The rats were not treated in the control group. In the denervation group and passive movement group, the right gastrocnemius muscle was denervated by sciatic nerve transection. In the passive movement group, the rats underwent passive movement of the right leg 300 times/day. After 2, 14 and 28 days bilateral gastrocnemius muscles were harvested, weighed and the ratio of muscle wet weight was calculated. Levels of NF-κB p65 mRNA and protein in the right gastrocnemius muscle were detected by RT-PCR and Western Blotting, respectively.Results After denervation rat gastrocnemius muscle weight ratio decreased with time. Expressions of NF-κB p65 mRNA and protein in the denervated skeletal muscle were up-regulated at 2, 14 and 28 days of denervation ( P ＜0.05). At 14 and 28 days of denervation, the passive movement group had a higher muscle wet weight ratio than the denervation group (P＜0.05). At 2, 14 and 28 days of denernation, the expression of NFκ B p65 in the passive movement group remarkably reduced comparing to the denervation group ( P ＜ 0.05). Conclusion Expressions of NF-κB p65 are up-regulated at the early stage of skeletal muscle denervation atrophy. Passive movement can delay denervation muscle atrophy through interfering the expression of NF-κB p65. Key words: Denervation; Muscular atrophy; NF-κB; Passive movement