Involvement of the calcium-dependent proteolytic system in skeletal muscle aging.
Aging is associated with a progressive and involuntary loss of muscle mass also known as sarcopenia. This condition represents a major public health concern with high socio-economics implications. Although sarcopenia is well documented, the aetiology of this condition still remains poorly understood. Calpains are ubiquitous proteases regulated in part by a specific inhibitor, calpastatin. They are well known to have major implications in muscle growth and differentiation. The aim of the present study was to determine if this proteolytic system could be involved in the phenotype associated with sarcopenia. Calpains and calpastatin levels, subcellular distributions and activities were compared between muscles from 3 and 24 months old rats. Altogether, the results we obtained showed an overall increase in calpain activities associated with muscle aging. These findings suggest that the calcium-dependent proteolytic system is indeed involved in sarcopenia.
Dargelos
Elise
E
Université Bordeaux I, INRA USC 2009, Unité Protéolyse Croissance et Développement Musculaire, ISTAB, avenue des facultés, 33405 Talence Cedex, France. e.dargelos@istab.u-bordeaux1.fr
Brulé
Cédric
C
Combaret
Lydie
L
Hadj-Sassi
Abdessatar
A
Dulong
Sandrine
S
Poussard
Sylvie
S
Cottin
Patrick
P
D000375:Aging / Q000378:metabolism*; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000378:metabolism; D002154:Calpain / Q000032:analysis / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D051381:Rats; D017207:Rats, Sprague-Dawley
D015415:Biomarkers; D002135:Calcium-Binding Proteins; C033668:calpastatin; D002154:Calpain; D002118:Calcium