Effet d’un exercice d’ultra-endurance sur le muscle squelettique

National audienc

Sarcopénie : définitions et contradictions - Approches histologique et moléculaire

National audienc

Protein profiling of the Human muscle during ultra-endurance exercise

National audienc

Label-free quantitative protein profiling of the Human muscle during ultra-endurance exercise

National audienc

Biological aging of skeletal muscle in humans

Grâce au rassemblement de la communauté de Lyon et de St Etienne, associant chercheurs, cliniciens, étudiants et entreprises, cette première conférence internationale visera à explorer comment et dans quelle mesure l’exercice peut être bénéfique pour les principales cellules de l’appareil locomoteur (muscle, tendon, os, cartilage, vaisseau). Cette journée offrira la possibilité de mettre en avant à la fois des travaux de recherche fondamentale réalisés à un niveau préclinique et des investigations conduites chez le volontaire sain ou sur des cohortes de patients. Des approches cellulaires, moléculaires et fonctionnelles seront mises en avant au cours de cette conférence. Présentation orale et poster Grâce au rassemblement de la communauté de Lyon et de St Etienne, associant chercheurs, cliniciens, étudiants et entreprises, cette première conférence internationale visera à explorer comment et dans quelle mesure l’exercice peut être bénéfique pour les principales cellules de l’appareil locomoteur (muscle, tendon, os, cartilage, vaisseau). Cette journée offrira la possibilité de mettre en avant à la fois des travaux de recherche fondamentale réalisés à un niveau préclinique et des investigations conduites chez le volontaire sain ou sur des cohortes de patients. Des approches cellulaires, moléculaires et fonctionnelles seront mises en avant au cours de cette conférence. Présentation orale et posterGrâce au rassemblement de la communauté de Lyon et de St Etienne, associant chercheurs, cliniciens, étudiants et entreprises, cette première conférence internationale visera à explorer comment et dans quelle mesure l’exercice peut être bénéfique pour les principales cellules de l’appareil locomoteur (muscle, tendon, os, cartilage, vaisseau). Cette journée offrira la possibilité de mettre en avant à la fois des travaux de recherche fondamentale réalisés à un niveau préclinique et des investigations conduites chez le volontaire sain ou sur des cohortes de patients. Des approches cellulaires, moléculaires et fonctionnelles seront mises en avant au cours de cette conférence.Présentation orale et posterAging is characterized by changes in body composition and particularly by a gradual loss of skeletal muscle mass, a phenomenon known as Sarcopenia. This age-related decline in muscle mass is accompanied by a loss of strength and a decline of physical performance, named Dynapenia. Both events decrease the autonomy and the quality of life of the individuals affecting about 40-50% of people over the age of 80. Nonetheless, inter-individual differences in prevalence of sarcopenia/dynapenia exist, as some remain fit and strong, whereas other become frail and weak when they get old. Until now, no study has examined the inter-individual variations of muscle tissue and its biomarkers. At the fiber level, age-related variations in skeletal muscle mass induce typological and capillarization modifications. Furthermore, the loss of muscle mass with aging could be associated with serious metabolic consequences or accumulation of intramyocellular lipid droplets. Immunohistochemical studies were performed with muscle biopsies from 30 healthy elderly men, aged 80 ±0.5 years selected from the PROgnostic indicator of cardiovascular and cerebrovascular events (PROOF) cohort, classified into three groups. On the basis of appendicular mass variation between two DEXA at mean interval of seven years, some people lose more muscle mass, named ”Lost”, others remain ”Stable”, and others ”Gain” muscle mass. The loss of skeletal muscle mass was associated with a reduction in Type-I fibers surface area (-24.6%), accompanied by a proportional loss of capillaries number around each fiber-type (CAF) and capillary-to-fiber perimeter exchange index (CFPE) (-15%, -10% respectively), compared to ”Stable” and ”Gain” groups. Also subjects from the ”Lost” group exhibited significant accumulation of intramyocellular lipid droplets in Type-I fibers compared to the ”Gain” (+23%). Lastly, this decline in muscle mass induced a remodeling of the extracellular matrix with an increase in the endomysium area (+12.2% vs Gain).If usually, it is recognized that chronological aging mainly affects Type-II motor units, our results suggest that biological aging is characterized by impairment of Type-I muscle fibers, their microvascular environment and oxidative metabolism for elderly men on their eighties

Biological aging of skeletal muscle in humans

Grâce au rassemblement de la communauté de Lyon et de St Etienne, associant chercheurs, cliniciens, étudiants et entreprises, cette première conférence internationale visera à explorer comment et dans quelle mesure l’exercice peut être bénéfique pour les principales cellules de l’appareil locomoteur (muscle, tendon, os, cartilage, vaisseau). Cette journée offrira la possibilité de mettre en avant à la fois des travaux de recherche fondamentale réalisés à un niveau préclinique et des investigations conduites chez le volontaire sain ou sur des cohortes de patients. Des approches cellulaires, moléculaires et fonctionnelles seront mises en avant au cours de cette conférence.Présentation orale et posterAging is characterized by changes in body composition and particularly by a gradual loss of skeletal muscle mass, a phenomenon known as Sarcopenia. This age-related decline in muscle mass is accompanied by a loss of strength and a decline of physical performance, named Dynapenia. Both events decrease the autonomy and the quality of life of the individuals affecting about 40-50% of people over the age of 80. Nonetheless, inter-individual differences in prevalence of sarcopenia/dynapenia exist, as some remain fit and strong, whereas other become frail and weak when they get old. Until now, no study has examined the inter-individual variations of muscle tissue and its biomarkers. At the fiber level, age-related variations in skeletal muscle mass induce typological and capillarization modifications. Furthermore, the loss of muscle mass with aging could be associated with serious metabolic consequences or accumulation of intramyocellular lipid droplets. Immunohistochemical studies were performed with muscle biopsies from 30 healthy elderly men, aged 80 ±0.5 years selected from the PROgnostic indicator of cardiovascular and cerebrovascular events (PROOF) cohort, classified into three groups. On the basis of appendicular mass variation between two DEXA at mean interval of seven years, some people lose more muscle mass, named ”Lost”, others remain ”Stable”, and others ”Gain” muscle mass. The loss of skeletal muscle mass was associated with a reduction in Type-I fibers surface area (-24.6%), accompanied by a proportional loss of capillaries number around each fiber-type (CAF) and capillary-to-fiber perimeter exchange index (CFPE) (-15%, -10% respectively), compared to ”Stable” and ”Gain” groups. Also subjects from the ”Lost” group exhibited significant accumulation of intramyocellular lipid droplets in Type-I fibers compared to the ”Gain” (+23%). Lastly, this decline in muscle mass induced a remodeling of the extracellular matrix with an increase in the endomysium area (+12.2% vs Gain).If usually, it is recognized that chronological aging mainly affects Type-II motor units, our results suggest that biological aging is characterized by impairment of Type-I muscle fibers, their microvascular environment and oxidative metabolism for elderly men on their eighties

Matrix assisted laser desorption ionization imaging by mass spectrometry of aging in human skeletal muscle

International audienc

Biological aging of skeletal muscle in humans

Grâce au rassemblement de la communauté de Lyon et de St Etienne, associant chercheurs, cliniciens, étudiants et entreprises, cette première conférence internationale visera à explorer comment et dans quelle mesure l’exercice peut être bénéfique pour les principales cellules de l’appareil locomoteur (muscle, tendon, os, cartilage, vaisseau). Cette journée offrira la possibilité de mettre en avant à la fois des travaux de recherche fondamentale réalisés à un niveau préclinique et des investigations conduites chez le volontaire sain ou sur des cohortes de patients. Des approches cellulaires, moléculaires et fonctionnelles seront mises en avant au cours de cette conférence.Présentation orale et posterAging is characterized by changes in body composition and particularly by a gradual loss of skeletal muscle mass, a phenomenon known as Sarcopenia. This age-related decline in muscle mass is accompanied by a loss of strength and a decline of physical performance, named Dynapenia. Both events decrease the autonomy and the quality of life of the individuals affecting about 40-50% of people over the age of 80. Nonetheless, inter-individual differences in prevalence of sarcopenia/dynapenia exist, as some remain fit and strong, whereas other become frail and weak when they get old. Until now, no study has examined the inter-individual variations of muscle tissue and its biomarkers. At the fiber level, age-related variations in skeletal muscle mass induce typological and capillarization modifications. Furthermore, the loss of muscle mass with aging could be associated with serious metabolic consequences or accumulation of intramyocellular lipid droplets. Immunohistochemical studies were performed with muscle biopsies from 30 healthy elderly men, aged 80 ±0.5 years selected from the PROgnostic indicator of cardiovascular and cerebrovascular events (PROOF) cohort, classified into three groups. On the basis of appendicular mass variation between two DEXA at mean interval of seven years, some people lose more muscle mass, named ”Lost”, others remain ”Stable”, and others ”Gain” muscle mass. The loss of skeletal muscle mass was associated with a reduction in Type-I fibers surface area (-24.6%), accompanied by a proportional loss of capillaries number around each fiber-type (CAF) and capillary-to-fiber perimeter exchange index (CFPE) (-15%, -10% respectively), compared to ”Stable” and ”Gain” groups. Also subjects from the ”Lost” group exhibited significant accumulation of intramyocellular lipid droplets in Type-I fibers compared to the ”Gain” (+23%). Lastly, this decline in muscle mass induced a remodeling of the extracellular matrix with an increase in the endomysium area (+12.2% vs Gain).If usually, it is recognized that chronological aging mainly affects Type-II motor units, our results suggest that biological aging is characterized by impairment of Type-I muscle fibers, their microvascular environment and oxidative metabolism for elderly men on their eighties

Mechanisms of myofibrillar proteolysis in skeletal muscle: role of E2 enzymes

ORGANIZING COMMITTEEChairs: Didier Attaix - Lydie Combaret - Daniel TaillandierDaniel Béchet - Agnès Claustre - Cécile Coudy-Gandilhon - Christiane Deval - Gérard Donadille - Cécile PolgeSCIENTIFIC COMMITTEEDidier Attaix - Lydie Combaret - Alfred L. Goldberg - Ron Hay - Germana Meroni - Marco Sandri - Daniel Taillandier - Keiji Tanaka - Simon S. WingThe Ubiquitin Proteasome System (UPS) is the major actor of muscle wasting during various physio-pathological situations. In the past 15 years, increasing data have depicted a picture, although incomplete, of the mechanisms responsible for in myofibrillar protein degradation, from the discovery of muscle-specific E3 ligases to the identification of the signaling pathways involved. The targeting specificity of the UPS relies on the capacity of the system to first recognize and then label the proteins to be degraded with a polyubiquitin (polyUb) chain. It is fairly assumed that the recognition step is accomplished by the numerous E3 ligases present in mammalian cells. The E3 ligase MuRF1 is so far the only enzyme known to direct different contractile proteins for degradation, i.e. troponin I, myosins and actin. However, like most E3s, MuRF1 does not possess any catalytic activity and depends on the activity of cognate E2 enzymes. The latter may be more than simple Ub-providers for E3s and they are probably important actors in the ubiquitination machinery. Surprisingly, while most efforts were put on E3s, the exact role of E2s in muscle protein degradation is still largely ignored. Amongst the 37 E2s described in humans, a very limited number have been addressed for their implication in skeletal muscle protein degradation and the vast majority of studies were only descriptive. Thus, we aim at identifying E2 enzymes that may be implicated in the ubiquitination of contractile proteins during skeletal muscle atroph

Vieillissement biologique du muscle squelettique chez l'Homme

Le thème des conférences portera sur : "La mobilité internationale pendant le doctorat"Vieillissement biologique du muscle squelettique chez l'Homme. Journée de la Recherche 2018, Ecole Doctorale Sciences, Ingénierie, Sant