Expression pattern of myostatin in gastrocnemius muscle of rats after sciatic nerve crush injury.

Myostatin is a strong inhibitor of skeletal muscle growth. The purpose of this study was to investigate myostatin expression profiles during denervation-induced muscle atrophy in order to understand the relationship between myostatin expression and muscle atrophy. We constructed a sciatic nerve crush model, undertook morphometric analyses of rat gastrocnemius muscle to evaluate the degree of muscle atrophy, and utilized a real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis to measure myostatin mRNA and protein expression levels, respectively, in the gastrocnemius at different time-points after nerve injury. Muscle atrophy changed in a parabola-like manner from day 1 to day 28 after nerve injury, with a maximum value at day 14. During this time, myostatin expression changed in the reverse manner, with myostatin mRNA or protein expression gradually increasing from days 1-14, and then gradually declining to day 28, when the normal level was reached. Statistical analyses further provided evidence for a significant negative linear correlation between myostatin expression and muscle atrophy within a 28-day period after nerve injury. Our study thus describes the expression pattern of myostatin in response to a specific type of muscle atrophy and raises the possibility of developing myostatin as a therapeutic target for future clinical applications.