Decrease of Both Cofilin and LIM Kinase Phosphorylation in the Skeletal Muscles of Immobilization-induced Atrophy Rats

[Purpose] Immobilization-induced atrophy is a general phenomenon caused by prolonged muscle disuse associated with orthopaedic conditions. However, changes in the phosphorylation of atrophy-related cofilin and LIM kinases are still poorly understood. In this study, we examined whether or not phosphorylation of cofilin and LIM kinases is altered in the skeletal muscles of rats after 3, 7, 14, and 21 days of cast immobilization. [Methods] We used two-dimensional gel electrophoresis, mass spectrometry, and western blotting to examine protein expression and phosphorylation in atrophied rat gastrocnemius muscles. [Results] The expression of the cofilin was detected in gastrocnemius muscle strips using proteomic analysis. Cast immobilization after 3, 7, 14, and 21 days significantly diminished the phosphorylation of cofilin and LIM kinases. [Conclusion] The present results suggest that cast immobilization-induced atrophy may be in part related to changes in the phosphorylation of cofilin and LIM kinases in rat skeletal muscles.