Upregulation of MHC class I in transgenic mice results in reduced force-generating capacity in slow-twitch muscle.
Muscle Nerve
; 39(5): 674-82, 2009 May.
Article
em En
| MEDLINE
| ID: mdl-19229963
ABSTRACT
Expression of major histocompatibility complex (MHC) class I in skeletal muscle fibers is an early and consistent finding in inflammatory myopathies. To test if MHC class I has a primary role in muscle impairment, we used transgenic mice with inducible overexpression of MHC class I in their skeletal muscle cells. Contractile function was studied in isolated extensor digitorum longus (EDL, fast-twitch) and soleus (slow-twitch) muscles. We found that EDL was smaller, whereas soleus muscle was slightly larger. Both muscles generated less absolute force in myopathic compared with control mice; however, when force was expressed per cross-sectional area, only soleus muscle generated less force. Inflammation was markedly increased, but no changes were found in the activities of key mitochondrial and glycogenolytic enzymes in myopathic mice. The induction of MHC class I results in muscle atrophy and an intrinsic decrease in force-generation capacity. These observations may have important implications for our understanding of the pathophysiological processes of muscle weakness seen in inflammatory myopathies. Muscle Nerve, 2008.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Antígenos de Histocompatibilidade Classe I
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Regulação para Cima
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Músculo Esquelético
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Fibras Musculares de Contração Lenta
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Distrofia Muscular Animal
Limite:
Animals
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article