LEUCINE ATTENUATES SKELETAL MUSCLE WASTING VIA INHIBITION OF UBIQUITIN LIGASES

Autor(es)

Baptista, Igor L. ^[1] ; Leal, Marcelo L. ^[1] ; Artioli, Guilherme G. ^[1] ; Aoki, Marcelo S. ^[2] ; Fiamoncini, Jarlei ^[3] ; Turri, Antonio O. ^[1] ; Curi, Rui ^[3] ; Miyabara, Elen H. ^[4] ; Moriscot, Anselmo S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Cell & Dev Biol, BR-05508900 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Sch Arts Sci & Humanities, BR-05508900 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, BR-05508900 Sao Paulo - Brazil

^[4] Univ Sao Paulo, Inst Biomed Sci, Dept Anat, BR-05508900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MUSCLE & NERVE; v. 41, n. 6, p. 800-808, JUN 2010.
• Citações Web of Science: 66

Resumo

The aim of this study was to assess the effect of leucine supplementation on elements of the ubiquitin proteasome system (UPS) in rat skeletal muscle during immobilization. This effect was evaluated by submitting the animals to a leucine supplementation protocol during hindlimb immobilization, after which different parameters were determined, including: muscle mass; cross-sectional area (CSA); gene expression of E3 ligases/deubiquitinating enzymes; content of ubiquitinated proteins; and rate of protein synthesis. Our results show that leucine supplementation attenuates soleus muscle mass loss driven by immobilization. In addition, the marked decrease in the CSA in soleus muscle type I fibers, but not type II fibers, induced by immobilization was minimized by leucine feeding. Interestingly, leucine supplementation severely minimized the early transient increase in E3 ligase {[}muscle ring finger 1 (MuRF1) and muscle atrophy F-box (MAFbx)/atrogin-1] gene expression observed during immobilization. The reduced peak of E3 ligase gene expression was paralleled by a decreased content of ubiquitinated proteins during leucine feeding. The protein synthesis rate decreased by immobilization and was not affected by leucine supplementation. Our results strongly suggest that leucine supplementation attenuates muscle wasting induced by immobilization via minimizing gene expression of E3 ligases, which consequently could downregulate UPS-driven protein degradation. It is notable that leucine supplementation does not restore decreased protein synthesis driven by immobilization. Muscle Nerve 41: 800-808, 2010 (AU)

• Processo FAPESP: 07/57613-3 - Efeitos celulares e moleculares da sobrecarga de leucina na atrofia muscular induzida pelo desuso
• Beneficiário: Igor Luchini Baptista
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 06/61523-7 - Aspectos celulares e moleculares da plasticidade muscular
• Beneficiário: Anselmo Sigari Moriscot
• Modalidade de apoio: Auxílio à Pesquisa - Temático