The Expression Patterns Of Foxo3a And Mafbx In The Myocytes Of Denervated Gastrocnemius In Rat

Objective: To investigate the expression patterns of FoxO3a and MAFbx in the myocytes ofdenervated gastrocnemius in rat.Methods:72Wistar rats are randomly divided into12groups with every group6rats. For everyrat the right sciatic nerve is cut off, and the left undergoes a sham operation. One group of rats iskilled respectively at the day0,1,2,3,4,5,6,7,10,14,21,28after the nerve is cut off and completelyget their right gastrocnemius muscles. After weighing on the analytical balance and comparingwith the left, the sample is frozen in the-70℃refrigerator. Use real-time PCR to detect themRNA level of FoxO3a and MAFbx for each sample. Use western blot to detect the proteinconcentration of FoxO3a and MAFbx and the phospho-Ser253FoxO3a (pFoxO3aS253) for eachsample.Result: Muscles are atrophying rapidly after denervation, muscles weigh only50%and30%of its own after14days’ and28days’ denervation, respectively.. The mRNA level of MAFbxreaches its peak at4days after denervation(39.1folds), and slowly goes to the normal level afterthat. The mRNA level of FoxO3a reaches its peak at5days after denervation(7.06folds), Whilekeeping on expressing at a high level although there is a slow decline.The protein concentrationof FoxO3a and MAFbx raises with the days of denervation passes, but the level ofphosphorylated FoxO3a is declining all the time. Only60.1%of FoxO3a is phosphorylatedcompared with the0day after denervation.Conclusion: the expression changes and the phosphorylation of FoxO3a and the expressionpattern of MAFbx is closely related to the process of muscle atrophy after denervation. BothFoxO3a and MAFbx can be a target for treating with drugs and gene method to retarddenervating atrophy.