Inhibition of interleukin-6 decreases atrogene expression and ameliorates tail suspension-induced skeletal muscle atrophy

BACKGROUND: Interleukin-6 (IL-6) is an inflammatory cytokine. Whether systemic IL-6 affects atrogene expression and disuse-induced skeletal muscle atrophy is unclear. METHODS: Tail-suspended mice were used as a disuse-induced muscle atrophy model. We administered anti-mouse IL-6 receptor antibody, beta-hydroxy-beta-methylbutyrate (HMB) and vitamin D to the mice and examined the effects on atrogene expression and muscle atrophy. RESULTS: Serum IL-6 levels were elevated in the mice. Inhibition of IL-6 receptor suppressed muscle RING finger 1 (MuRF1) expression and prevented muscle atrophy. HMB and vitamin D inhibited the serum IL-6 surge, downregulated the expression of MuRF1 and atrogin-1 in the soleus muscle, and ameliorated atrophy in the mice. CONCLUSION: Systemic IL-6 affects MuRF1 expression and disuse-induced muscle atrophy.