Project description:To investigate the metabolic dysfunction in the process of sarcopenia, we collected the skeletal muscles from the participants of healthy aged, pre-sarcopenia and sarcopenia. We then performed gene expression profiling analysis using data obtained from RNA-seq of skeletal muscle tissue from healthy aged, pre-sarccopenia and sarcopenia.
Project description:Skeletal muscle aging results in a gradual loss of skeletal muscle mass, skeletal muscle function and decreased regenerative capacity, which can lead to sarcopenia and increased mortality. While the mechanisms underlying sarcopenia remain unclear, the skeletal muscle stem cell, or satellite cell, is required for muscle regeneration. Therefore, identification of signaling pathways affecting satellite cell function during aging may provide insights into therapeutic targets for combating sarcopenia. Here, we show that a cell-autonomous loss in self-renewal occurs via novel alterations in FGF and p38αβ MAPK signaling in old satellite cells. We further demonstrate that pharmacological manipulation of these pathways can ameliorate age-associated self-renewal defects. Thus, our data highlight an age-associated deregulation of a satellite cell homeostatic network and reveals potential therapeutic opportunities for the treatment of progressive muscle wasting. Satellite cells were isolated from young (3-6mo) and aged (20-25mo) adult mice; individual date files represent 2 independent pools of RNA from 4-8 mice at each timepoint.
Project description:Sarcopenia is the age-induced, progressive loss of skeletal muscle mass and function, which is accompanied by reduced muscle performance. Individuals with sarcopenia often become bedridden or dependent on a wheelchair, leading to decreased quality of life. In this study, to better understand changes in skeletal muscle during sarcopenia, we performed a microarray analysis of skeletal muscle in young (13-week-old) and aged (26-month-old) mice. The microarray data shows that expression of the enzymes related to glucose and polyamine metabolism were decreased in aged mice compared with young mice.
Project description:Skeletal muscle aging results in a gradual loss of skeletal muscle mass, skeletal muscle function and decreased regenerative capacity, which can lead to sarcopenia and increased mortality. While the mechanisms underlying sarcopenia remain unclear, the skeletal muscle stem cell, or satellite cell, is required for muscle regeneration. Therefore, identification of signaling pathways affecting satellite cell function during aging may provide insights into therapeutic targets for combating sarcopenia. Here, we show that a cell-autonomous loss in self-renewal occurs via novel alterations in FGF and p38αβ MAPK signaling in old satellite cells. We further demonstrate that pharmacological manipulation of these pathways can ameliorate age-associated self-renewal defects. Thus, our data highlight an age-associated deregulation of a satellite cell homeostatic network and reveals potential therapeutic opportunities for the treatment of progressive muscle wasting.
Project description:Age-related sarcopenia is associated with a variety of changes in skeletal muscle. These changes are interrelated with each other and associated with systemic metabolism, the details of which, however, are largely unknown. Eicosapentaenoic acid (EPA) is a promising nutrient against sarcopenia and has multifaceted effects on systemic metabolism. Although several human studies have suggested that EPA supplementation protects against sarcopenia, the causal relationship of EPA supplementation and an increase of muscle strength has poor evidence in vivo. We demonstrated that aging skeletal muscle in male mice shows lower grip strength and fiber type changes, both of which can be inhibited by EPA supplementation irrespective of muscle mass alteration. We hypothesized that the aging process in skeletal muscle can be intervened by the administration of EPA, via transcriptomic changes in skeletal muscle. This analysis revealed fast-to-slow fiber type transition in aging muscle, which was partially inhibited by EPA.
Project description:Skeletal muscle aging is characterized by a progressive decline in muscle mass and function, which is referred to as sarcopenia. However, the molecular mechanisms implicated in sarcopenia remain unclear. In this dataset, we include the expression data obtained from gastrocnemius muscle of young, mature adult and old C57BL6 male mice.
Project description:Evidence suggests that immobilization is a promoting factor of sarcopenia; mechanism how immobilization accelerates the development of sarcopenia is not known. We have recently established a model of immobilization-induced skeletal muscle mass loss in mice. We used microarrays to detail the global programme of gene expression underlying skeletal muscle atrophy in immobilized mice and identified up-regulated or down-regulated genes during this process.
Project description:Aging associates with progressive loss of skeletal muscle function leading up to sarcopenia, a process characterized by impaired mobility and weakening of muscle strength. Molecular mechanisms underpinning sarcopenia are still poorly characterized. Since aging associates with profound epigenetic changes, epigenetic landscape alteration analysis in the skeletal muscle promises to highlight molecular mechanisms of age-associated sarcopenia. The study was conducted exploiting the short-lived Nothobranchius furzeri (Nfu), a relatively new model for aging studies. The epigenetic analysis suggested for a less accessible and more condensed chromatin structure in old Nfu skeletal muscle. Specifically, an accumulation of heterochromatin regions was observed as consequence of increased levels of H3K27me3, HP1a, polycomb complex subunits and senescence associated heterochromatic foci (SAHFs). Consistently, euchromatin histone marks, including H3K9ac, decreased. The integrative bioinformatics analysis of RNASeq and ChIPSeq, related to skeletal muscle of Nfu at different ages, revealed a down-modulation of transcripts involved in cell cycle, differentiation and DNA repair and an up-regulation of inflammation and senescence genes. Undoubtedly, more studies are needed to disclose the detailed mechanisms, but this approach shed light on unprecedented specific features of Nfu skeletal muscle aging, potentially associated with sarcopenia onset and consequent impairment of swimming and mobility typical of old Nfu.
Project description:Aging associates with progressive loss of skeletal muscle function leading up to sarcopenia, a process characterized by impaired mobility and weaken muscle strength. Sarcopenia underpinning molecular mechanisms are still poorly characterized. Since, aging associates with profound epigenetic changes, the investigation of the epigenetic landscape alteration in the skeletal muscle promises to highlight molecular mechanisms of age-associated sarcopenia. Here, the study was conducted exploiting the short-lived Nothobranchius furzeri (Nfu), a relatively new model for aging studies. The epigenetic analysis suggested for a less accessible and more condensed chromatin in old Nfu skeletal muscle. Specifically, an accumulation of heterochromatin regions was observed as consequence of increased levels of H3K27me3, HP1a, polycomb complex subunit expression and SAHFs. Consistently, euchromatin histone marks, including H3K9ac, decreased. The integrative bioinformatics analysis of RNASeq and ChIPSeq dataset, related to skeletal muscle of Nfu at different ages, revealed a down-modulation of transcripts involved in cell cycle, differentiation and DNA repair and an up-regulation of inflammation and senescence genes. Undoubtedly, more studies are needed to disclose the detailed mechanisms, but this approach shed light on unprecedented specific features of Nfu skeletal muscle aging, responsible of sarcopenia onset and consequent impairment of swimming and mobility activity typical of old Nfu.