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Reid, W. Darlene; MacGowan, N A

doi:10.1023/a:1006803703128

Cited by 54 publications

(9 citation statements)

References 99 publications

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“…However, a predominantly subsarcolemmal distribution is associated with large intracellular diffusion distances for metabolites, which would have functional consequences (Kinsey et al 2007) and may also be associated with pathological features such as muscle weakness and hypotonia (Reid and MacGowan 1998). …”

Section: Pathways and Stimuli Regulating Protein Turnover In Differenmentioning

confidence: 99%

The muscle fiber type–fiber size paradox: hypertrophy or oxidative metabolism?

et al. 2010

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An inverse relationship exists between striated muscle fiber size and its oxidative capacity. This relationship implies that muscle fibers, which are triggered to simultaneously increase their mass/strength (hypertrophy) and fatigue resistance (oxidative capacity), increase these properties (strength or fatigue resistance) to a lesser extent compared to fibers increasing either of these alone. Muscle fiber size and oxidative capacity are determined by the balance between myofibrillar protein synthesis, mitochondrial biosynthesis and degradation. New experimental data and an inventory of critical stimuli and state of activation of the signaling pathways involved in regulating contractile and metabolic protein turnover reveal: (1) higher capacity for protein synthesis in high compared to low oxidative fibers; (2) competition between signaling pathways for synthesis of myofibrillar proteins and proteins associated with oxidative metabolism; i.e., increased mitochondrial biogenesis via AMP-activated protein kinase attenuates the rate of protein synthesis; (3) relatively higher expression levels of E3-ligases and proteasome-mediated protein degradation in high oxidative fibers. These observations could explain the fiber type–fiber size paradox that despite the high capacity for protein synthesis in high oxidative fibers, these fibers remain relatively small. However, it remains challenging to understand the mechanisms by which contractile activity, mechanical loading, cellular energy status and cellular oxygen tension affect regulation of fiber size. Therefore, one needs to know the relative contribution of the signaling pathways to protein turnover in high and low oxidative fibers. The outcome and ideas presented are relevant to optimizing treatment and training in the fields of sports, cardiology, oncology, pulmonology and rehabilitation medicine.Electronic supplementary materialThe online version of this article (doi:10.1007/s00421-010-1545-0) contains supplementary material, which is available to authorized users.

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Section: Pathways and Stimuli Regulating Protein Turnover In Differenmentioning

confidence: 99%

The muscle fiber type–fiber size paradox: hypertrophy or oxidative metabolism?

et al. 2010

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“…Increased myofibrillar proteolysis results in muscle weakness and fatigue that in turn delays or prevents ambulation. When respiratory muscles are involved (2), there is an increased risk for pulmonary complications and extended periods of ventilatory support. In patients with cancer, muscle cachexia is a contributory factor to morbidity and mortality.…”

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confidence: 99%

Molecular Regulation of Muscle Cachexia: It May Be More Than the Proteasome

Hasselgren

Wray

Mammen

2002

Biochemical and Biophysical Research Communications

126

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“…For example, Levine et al [1] described adaptations such as a shift towards type I fibres and an increase in oxidative enzyme activity [2]. Beside these positive adaptations, alterations in diaphragm function, e.g., loss of fibre myosin heavy chain content and reduced in vitro force generation [21], and histology, e.g., increased collagen disposition and general signs of muscle injury, such as sarcomeric disruptions and Z-band streaming [4,5,6], were reported. Conversely, our findings point to no differences in expression of the focal adhesion complex, the dystroglycan complex and the spectrin-based membrane cytoskeleton, and of laminin, in the diaphragm of COPD compared with non-COPD patients.…”

Section: Discussionmentioning

confidence: 99%

“…These adaptations are believed to be advantageous, since they may attenuate fatigability [1, 3]. However, in the diaphragm of COPD patients, increased collagen disposition and evidence of muscle injury has been reported, such as sarcomeric disruptions and Z-band streaming, which are likely to negatively influence diaphragm function [4,5,6]. Furthermore, in an emphysematous hamster model of COPD, injury has also been demonstrated ultrastructurally [7].…”

Section: Introductionmentioning

confidence: 99%

Distribution of Costameric Proteins in the Diaphragm of Patients with Chronic Obstructive Pulmonary Disease

Wijnhoven

Hafmans²,

Dekhuijzen³

2006

Respiration

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Background: Chronic obstructive pulmonary disease (COPD) is associated with an increased load on the diaphragm. Increased (eccentric) loading has been shown to result in disturbances in the cytoskeleton. Objectives: We hypothesized that due to a continuous overload of the diaphragm in COPD patients, distinct alterations in the membrane-associated cytoskeleton occur, especially in the costameres. Methods: Diaphragm biopsies from 7 COPD patients (forced expiratory volume in 1 s 62 ± 3% predicted) and 5 non-COPD patients (forced expiratory volume in 1 s 105 ± 6% predicted) were obtained. Cryosections of these biopsies were stained with antibodies against the costameric proteins of the focal adhesion complex (vinculin, talin and integrin-β₁), the dystroglycan complex (dystrophin and β-dystroglycan) and the spectrin-based membrane cytoskeleton (β-spectrin). Furthermore, in these cryosections, the basal membrane protein laminin was stained. Results: We found no differences in the distribution and staining intensity of the costameric proteins of the focal adhesion complex, the dystroglycan complex and the spectrin-based membrane cytoskeleton in the diaphragm between the COPD and the non-COPD patients. Furthermore, no differences were observed in the expression of laminin in the diaphragm between COPD and non-COPD patients. Conclusions: These results indicate that the increased loading to which the diaphragm is exposed in COPD does not result in disturbances in expression of the costameric system and histological damage of the sarcolemma.

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Untitled

Cited by 54 publications

References 99 publications

The muscle fiber type–fiber size paradox: hypertrophy or oxidative metabolism?

The muscle fiber type–fiber size paradox: hypertrophy or oxidative metabolism?

Molecular Regulation of Muscle Cachexia: It May Be More Than the Proteasome

Distribution of Costameric Proteins in the Diaphragm of Patients with Chronic Obstructive Pulmonary Disease

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