title: Leucine supplementation improves skeletal muscle regeneration after cryolesion in rats.
abstract: This study was undertaken in order to provide further insight into the role of leucine supplementation in the skeletal muscle regeneration process, focusing on myofiber size and strength recovery. Young (2-month-old) rats were subjected or not to leucine supplementation (1.35 g/kg per day) started 3 days prior to cryolesion. Then, soleus muscles were cryolesioned and continued receiving leucine supplementation until 1, 3 and 10 days later. Soleus muscles from leucine-supplemented animals displayed an increase in myofiber size and a reduction in collagen type III expression on post-cryolesion day 10. Leucine was also effective in reducing FOXO3a activation and ubiquitinated protein accumulation in muscles at post-cryolesion days 3 and 10. In addition, leucine supplementation minimized the cryolesion-induced decrease in tetanic strength and increase in fatigue in regenerating muscles at post-cryolesion day 10. These beneficial effects of leucine were not accompanied by activation of any elements of the phosphoinositide 3-kinase/Akt/mechanistic target of rapamycin signalling pathway in the regenerating muscles. Our results show that leucine improves myofiber size gain and strength recovery in regenerating soleus muscles through attenuation of protein ubiquitination. In addition, leucine might have therapeutic effects for muscle recovery following injury and in some muscle diseases.
authors.affiliation: Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Marcelo G
authors.initials: MG
authors.lastname: Pereira
authors.affiliation: Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Igor L
authors.initials: IL
authors.lastname: Baptista
authors.affiliation: Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Eduardo O C
authors.initials: EO
authors.lastname: Carlassara
authors.affiliation: Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Anselmo S
authors.initials: AS
authors.lastname: Moriscot
authors.affiliation: School of Arts, Sciences and Humanities, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Marcelo S
authors.initials: MS
authors.lastname: Aoki
authors.affiliation: Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Elen H
authors.initials: EH
authors.lastname: Miyabara
mesh_terms: D064413:3-Phosphoinositide-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D000284:Administration, Oral; D000818:Animals; D003080:Cold Temperature; D019587:Dietary Supplements; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006614:Hindlimb; D007930:Leucine / Q000008:administration & dosage*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000293:injuries / Q000378:metabolism; D009136:Muscular Dystrophies / Q000178:diet therapy* / Q000235:genetics / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000187:drug effects*; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination / Q000187:drug effects
chemical_list: C499515:FOXO3 protein, rat; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; C546845:mTOR protein, rat; D064413:3-Phosphoinositide-Dependent Protein Kinases; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; D007930:Leucine