title: Time-dependent expression of myostatin RNA transcript and protein in gastrocnemius muscle of mice after sciatic nerve resection.
abstract: Myostatin, a member of the transforming growth factor-beta (TGF-beta) superfamily, has been identified as a negative regulator of skeletal muscle mass. To provide more data on the role of myostatin in denervation-induced muscle atrophy, we examined the time-dependent changes in myostatin mRNA and protein as well as Smad2 and phospho-Smad2 protein levels in the denervated gastrocnemius muscle of mice after sciatic neurectomy, using quantitative real-time RT-PCR and Western blotting, respectively. We conducted morphometric analyses to measure the wet weight ratio of the denervated muscle (the operated side/contralateral nonoperated side) and the cross-sectional area of muscle fibers, and observed the morphology of denervated muscle. The experimental results showed that in the early stage of denervation, the levels of myostatin mRNA and protein in the denervated gastrocnemius muscle increased instantly, reaching a peak at day 3 and day 7 after sciatic neurectomy, respectively, when compared with the normal values. In addition, the phospho-Smad2 protein was observed to have a similar expression profile to that of the myostatin mRNA. The present study perhaps opens a new window into myostatin modulation in muscle atrophy due to denervation.
authors.affiliation: Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong, JS 226001 People's Republic of China.
authors.forename: Chenxin
authors.initials: C
authors.lastname: Shao
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Xin
authors.initials: X
authors.lastname: Wu
authors.forename: Fei
authors.initials: F
authors.lastname: Ding
mesh_terms: D000818:Animals; D015153:Blotting, Western; D017931:DNA Primers; D005786:Gene Expression Regulation / Q000502:physiology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D023421:Models, Animal; D009121:Muscle Denervation; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D009133:Muscular Atrophy / Q000378:metabolism*; D055435:Myostatin; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012584:Sciatic Nerve / Q000293:injuries / Q000601:surgery; D020426:Sciatic Neuropathy / Q000378:metabolism; D051899:Smad2 Protein / Q000378:metabolism; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000235:genetics* / Q000378:metabolism
chemical_list: D017931:DNA Primers; C525912:Mstn protein, mouse; D055435:Myostatin; D012333:RNA, Messenger; D051899:Smad2 Protein; C497783:Smad2 protein, mouse; D016212:Transforming Growth Factor beta