Titre :
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Identification of biomarkers of human muscle aging and senescence
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contenu dans :
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Auteurs :
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Congrès international de myologie 2008 (International Congress of Myology 2008; 26-30 mai 2008; Marseille, France) ;
Butler-Browne GS ;
LeBihan MC ;
Bigot A ;
Gasnier E ;
Furling D ;
Bechet D ;
Mouly V
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Type de document :
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Article
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Année de publication :
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2008
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Pages :
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p. 9
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Langues:
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Anglais
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Mots-clés :
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âge
;
biopsie musculaire
;
capillaire
;
croissance musculaire
;
diamètre des fibres musculaires
;
étude transversale
;
fibre musculaire
;
force musculaire
;
masse musculaire
;
muscle squelettique
;
myoblaste
;
sarcolemme
;
vieillissement
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Résumé :
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Muscle loss is the most common phenomenon of normal healthy aging and frequently leads to frailty and loss of independence in the elderly. It is important to understand the basic cellular mechanisms underlying this impairment. Decrease in muscle strength is associated with a decrease in cross sectional area of the muscle fibres, a decrease in capillary bed density as well as an increase in fibrotic tissue. A proteomic analysis is currently being carried out on biopsies of human skeletal muscle from young and old individuals in order to identify biomarkers of normal aging. Satellite cells are adult muscle stem cells, which are responsible for muscle growth and muscle repair. These cells are closely associated with the muscle fibre located outside the muscle fibre sarcolemma but beneath the basement lamina. We have shown that the number and quality of these satellite cells available for both repairing and maintaining muscle mass decreases during aging suggesting that regeneration may be compromised in older individuals. We have also shown that these cells can make only a limited number of divisions and that this number decreases as a function of age and following transplantation into immunodeficient mice cells from older individuals make less fibres than cells from young individuals. We are currently using a proteomic approach to characterise the secretome and the proteome of young and senescent muscle stem cells. P16 has proved to be a reliable biomarker of approaching senescence in the muscle stem cells and of premature senescence in pathological situations. This increase in P16 is accompanied by modifications in several novel proteins, which have been shown to be involved in stem cell proliferation and fusion. The regulation of p16 during both senescence and in stress-induced senescence is currently under investigation.
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