Involvement of Reactive Oxygen Species (ROS) inskeletal muscle function during ageing: Study in amodel of isolated single skeletal muscle fibre

[ES] Suplemento de la revista Free Radical Biology and Medicine: Involvement of Reactive Oxygen Species (ROS) inskeletal muscle function during ageing: Study in amodel of isolated single skeletal muscle fibre

Redox proteomic analysis of the gastrocnemius muscle from adult and old mice.

The data provides information in support of the research article, "Differential Cysteine Labeling and Global Label-Free Proteomics Reveals an Altered Metabolic State in Skeletal Muscle Aging", Journal of Proteome Research, 2014, 13 (11), 2008-21 [1]. Raw data is available from ProteomeXchange [2] with identifier PDX001054. The proteome of gastrocnemius muscle from adult and old mice was analyzed by global label-free proteomics and the relative quantification of specific reduced and reversibly oxidized Cysteine (Cys) residues was performed using Skyline [3]. Briefly, reduced Cysteine (Cys) containing peptides was alkylated using N-ethylmalemide (d0-NEM). Samples were desalted and reversibly oxidized Cys residues were reduced using tris(2-carboxyethyl)phosphine (TCEP) and the newly formed reduced Cys residues were labeled with heavy NEM( d5-NEM). Label-free analysis of the global proteome of adult (n=5) and old (n=4) gastrocnemius muscles was performed using Peaks7™ mass spectrometry data analysis software [4]. Relative quantification of Cys containing peptides that were identified as reduced (d(0) NEM labeled) and reversibly oxidized d(5)-NEM labeled was performed using the intensity of their precursor ions in Skyline. Results indicate that muscles from old mice show reduced redox flexibility particularly in proteins involved in the generation of precursor metabolites and energy metabolism, indicating a loss in the flexibility of the redox energy response

Reactive oxygen species and loss of muscle fibres during ageing

[ES] Sumario de la revista Neuromuscular Disorders: Especies reactivas de oxígeno y pérdida de fibras musculares durante el envejecimiento

Cosmopolitanism and transnational elite entrepreneurial practices: manifesting the cosmopolitan disposition in a cosmopolitan city

Purpose The paper aims to focus on the role that cosmopolitanism and, in particular, “the cosmopolitan disposition” (Woodward et al., 2008) plays in the process of entrepreneurial business by transnational business elites in Dubai. Design/methodology/approach Adopting a relational perspective based on Bourdieu and Wacquant’s (1992) Reflexive Sociology, as well as an inductive design, the authors conducted 30 semi-structured interviews focusing on both expatriates and Emiratis (locals/nationals) who displayed key features of a transnational business elite. Findings The findings indicate that the cosmopolitan disposition is an asset for transnational business elites when they venture in the context of Dubai. Research limitations/implications The findings would have to be further replicated in similar contexts, i.e. other major cities displaying similar cosmopolitan features with Dubai. A theoretical framework that calls for further study of transnational entrepreneurship via the lens of cosmopolitan disposition and Bourdieuan “habitus” is proposed. Practical implications The research outlines cosmopolitan skills for a transnational business elite which are required when entrepreneurial ventures are developed in the context of a city like Dubai. Social implications Cosmopolitanism and transnational entrepreneurship change cities like Dubai around the world constantly. Therefore, this study aims at achieving a better understanding of these changes and the ways in which they occur. Originality/value Studies on transnational entrepreneurship have already adopted Bourdieu’s theory (1977/1986), but this is the first time the cosmopolitan perspective and disposition is researched using this approach

Redox Regulation in Health and Disease Application of redox proteomics to skeletal muscle aging and exercise

Abstract Skeletal muscle represents a physiologically relevant model for the application of redox proteomic techniques to dissect its response to exercise and aging. Contracting skeletal muscles generate ROS (reactive oxygen species) and RNS (reactive nitrogen species) necessary for the regulation of many proteins involved in excitation-contraction coupling. The magnitude and species of ROS/RNS generated by contracting muscles will have downstream effects on specific protein targets and cellular redox signalling. Redox modifications on specific proteins are essential for the adaptive response to exercise and skeletal muscle can develop a dysregulated redox response during aging. In the present article, we discuss how redox proteomics can be applied to identify and quantify the reversible modifications on susceptible cysteine residues within those redox-sensitive proteins, and the integration of oxidative and non-oxidative protein modifications in relation to the functional proteome. Skeletal muscle as a redox model Skeletal muscle represents the largest organ of the human body and comprises approximately 40 % of total body mass in humans. Over the age of 50, there is a decline in skeletal muscle mass in adults. The decline in muscle mass and associated function is referred to as sarcopenia, and can lead to a reduction in the ability to perform daily tasks and loss of independence amongst the elderly Key words: aging, cysteine modification, exercise, redox proteomics, signalling, skeletal muscle. Abbreviations: eNOS, endothelial NOS; ICAT, isotope-coded affinity tag; iTRAQ, isobaric tag for relative and absolute quantification; MRM, multiple reaction monitoring; NOS, nitric oxide synthase; PTM, post-translational modification; RNS, reactive nitrogen species; ROS, reactive oxygen species. 1 To whom correspondence should be addressed (email [email protected]). A number of questions remain as to the source of the signals required for the generation of ROS and RNS, the identification of their specific protein targets (and modifications) and how the redox signals are relayed throughout the muscle fibre. The intensity of muscle contractions, muscle fibre type, and the fitness and the age of the individual may all have an effect on both the levels and type of ROS/RNS generated. Aging muscle has an altered redox response with subsequent physiological and biochemical effects on the cytoskeleton, mitochondria, Ca 2 + signalling and sequestration. Exercise is known to induce the generation of ROS and RNS that results in the activation of a number of transcription factors, including NF-κB (nuclear factor κB), AP-1 (activator protein 1) and HSF-1 (heat-shock factor 1), and induces mitochondrial biogenesis (for a review, see Defining the biochemical pathways and processes within skeletal muscles that are affected by ROS/RNS and how these responses change with age and exercise could help our understanding of biological aging. Moderate levels of ROS/RNS generally act through a reversible thiol-disulfideexchange mechanism on specific cysteine residues and can modify key target proteins by altering both the structur

Fair Resource Sharing for Dynamic Scheduling of Workflows on Heterogeneous Systems

International audienceScheduling independent workflows on shared resources in a way that satisfy users Quality of Service is a significant challenge. In this study, we describe methodologies for off-line scheduling, where a schedule is generated for a set of knownworkflows, and on-line scheduling, where users can submit workflows at any moment in time. We consider the on-line scheduling problem in more detail and present performance comparisons of state-of-the-art algorithms for a realistic model of a heterogeneous system

Vitamin D status in chronic fatigue syndrome/myalgic encephalomyelitis: a cohort study from the North-West of England

Objective Severe vitamin D deficiency is a recognised cause of skeletal muscle fatigue and myopathy. The aim of this study was to examine whether chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is associated with altered circulating vitamin D metabolites. Design Cohort study. Setting UK university hospital, recruiting from April 2014 to April 2015. Participants Ninety-two patients with CFS/ME and 94 age-matched healthy controls (HCs). Main outcome measures The presence of a significant association between CFS/ME, fatigue and vitamin D measures. Results No evidence of a deficiency in serum total 25(OH) vitamin D (25(OH)D2 and 25(OH)D3 metabolites) was evident in individuals with CFS/ME. Liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis revealed that total 25(OH)D was significantly higher (p=0.001) in serum of patients with CFS/ME compared with HCs (60.2 and 47.3 nmol/L, respectively). Analysis of food/ supplement diaries with WinDiets revealed that the higher total 25(OH) vitamin D concentrations observed in the CFS/ ME group were associated with increased vitamin D intake through use of supplements compared with the control group. Analysis of Chalder Fatigue Questionnaire data revealed no association between perceived fatigue and vitamin D levels. Conclusions Low serum concentrations of total 25(OH) D do not appear to b