Expression of myostatin in atrophic gastrocnemius of mouse after denervation

Objective: To investigate the expression of myostatin and explore its potential role in atrophic gastrocnemius after denervation.Methods: The mouse model of sciatic nerve resection was prepared to examine the levels of myostatin mRNA and protein expression in the atrophying mouse gastrocnemius muscle at different time points after denervation by realtime quantitative RT-PCR and Western blot,respectively.In parallel,morphometric analyses of the atrophying muscle including measurements of the wet weight ratio of the muscle and the cross section area (CSA) of the muscle fibers were also conducted.Results: The level of myostatin mRNA in gastrocnemius increased instantly at day 1 after denervation,reached the peak value at day 3 after denervation,followed by a subsequent decrease;while the level of myostatin protein increased continuously after denervation,reached a peak at day 7 after denervation,and then decreased gradually until day 56 after denervation.But the level of both myostatin mRNA and protein at day 56 after denervation was still higher than the normal level.The significant decrease of the muscle wet weight ratio and CSA were also observed.Conclusion: Myostatin might play an important role in the process of mouse gastrocnemius atrophy after denervation.