Ageing affects the differentiation potential of human myoblasts

DIGE analysis of rat skeletal muscle proteins using nonionic detergent phase extraction of young adult versus aged gastrocnemius tissue

“…Most physiological and histological studies of fibre aging indicate that sarcopenia is due to a multi-factorial pathology. Skeletal muscle aging is associated with a wide variety of cellular, biochemical and physiological alterations, including (i) grouped atrophying fibres, increased numbers of centrally located nuclei and variability in fibre diameter [9], (ii) metabolic alterations [43], (iii) mitochondrial disturbances and an increased susceptibility to apoptosis [44], (iv) a decreased regenerative capacity [45], (v) disturbed luminal ion binding and cycling [46], (vi) excitation-contraction uncoupling [47], (vii) oxidative stress [48], (viii) a blunted cellular stress response [49], (ix) impaired protein synthesis of myofibrillar components [50], ( (x) denervation-associated atrophy [51], (xi) an altered equilibrium of growth factors and hormones involved in fibre maintenance [52], and (xii) a severe decline in contractile efficiency [53]. Our proteomic map of alterations in protein expression in the aqueous versus detergent-extracted fractions from aged muscle agrees with the idea of complex biochemical changes in sarcopenia.…”

Lectin-based proteomic profiling of aged skeletal muscle: Decreased pyruvate kinase isozyme M1 exhibits drastically increased levels of N-glycosylation

“…This includes increased oxidative stress, mitochondrial abnormalities, disturbed microcirculation, hormonal imbalance, incomplete ion homeostasis, denervation, and impaired excitation-contraction coupling (Larsson, 1998;Degens, 1998;Squier and Bigelow, 2000;Bua et al, 2002;Delbono, 2002), as well as a decreased regenerative potential (Renault et al, 2002;Lorenzon et al, 2004;Beccafico et al, 2007). In addition, altered posttranslational modifications, such as tyrosine nitration, were recently described as occuring in an age-related manner on numerous skeletal muscle proteins (Kanski et al, 2003(Kanski et al, , 2005.…”

Drastic increase of myosin light chain MLC-2 in senescent skeletal muscle indicates fast-to-slow fibre transition in sarcopenia of old age

“…Striking histological alterations in aged skeletal muscles include an extensive variability in fibre diameter, an increased number of centrally located nuclei, grouped atrophying fibres and a higher frequency of longitudinal splitting (Edstrom et al, 2007). Previous studies into muscle aging have clearly documented the complexity of pathological changes (Faulkner et al, 2007), including a severe decline in contractile efficiency (Prochniewicz et al, 2007), mitochondrial abnormalities (Chabi et al, 2008), metabolic alterations (Vandervoort and Symons, 2001), a progressive decline in energy intake (Thomas, 2007), a drastically decreased regenerative capacity (Lorenzon et al, 2004), disturbed ion homeostasis (O'Connell et al, 2008a), uncoupling between neuronal excitation and muscle contraction (Delbono et al, 1995), decreased capillarisation (Degens, 1998), oxidative stress (Squier and Bigelow, 2000), a partially diminished cellular stress response (Kayani et al, 2008), impaired protein synthesis of myofibrillar components (Balagopal et al, 1997), increased apoptosis (Marzetti and Leeuwenburgh, 2006), denervationassociated atrophy (Carlson, 2004) and an altered equilibrium of growth factors and hormones important for the maintenance of proper muscle function (Lee et al, 2007).…”