Project description:Muscle stem cells, also known as satellite cells, represent the main myogenic population accounting for skeletal muscle homeostasis and regeneration. Here, using the Assay for Transposase Accessible Chromatin followed by sequencing (ATAC-seq), we investigated the epigenetic landscape of activated human and murine satellite cells. Our analysis identified a compendium of putative regulatory elements defining activated satellite cells and myoblasts, respectively.
Project description:There is considerable crosstalk between satellite cells, endothelilal cells and muscle fibers. Transcriptome analysis from freshly isolated cells from each compartment should help elucidate these pathways.
Project description:Transcriptional profiling of mouse skeletal muscle-derived cells comparing satellite cells with PDGFRa+ cells. Satellite cells and PDGFRa+ cells were directly isolated from diaphragm of dystrophic mdx mouse by FACS. Two-condition experiment, satellite cells vs. PDGFRa+ cells. Freshly isolated. One replicate per array.
Project description:Calcitonin receptor (CalcR) signaling is essential pathway for maintaining quiescence in muscle stem cells (Stem Cells. 2007 Oct;25(10):2448-59, Cell Rep. 2015 Oct 13;13(2):302-14). Collagen V functions as a surrogate ligand for CalcR, and Protein kinase A (PKA)-mediated Yap1 suppression serve as the downstream of CalcR in quiescent muscle stem cells (Nature. 2018 May;557(7707):714-718, Cell Rep. 2019 Nov 19;29(8):2154-2163.e5.). The aim of this study is to further characterize CalcR-cKO MuSCs. The aim of this study is to characterize CalcR-cKO MuSCs.
Project description:(Abstract of publication submitted currently) To clarify molecular regulation of satellite cells, we performed genome-wide gene expression analysis of quiescent satellite cells isolated from mouse skeletal muscle by flow cytometry. We identified 53 novel quiescent satellite cell-specific genes whose expressions are sharply down-regulated upon activation. The gene list contains a number of cell surface molecules, transcriptional factors, and cytokines and other signal transduction molecules. We further confirmed that Odz4 and calcitonin receptor proteins were expressed by quiescent but not by activated satellite cells in vivo. Importantly, we found that Pax7+/calcitonin receptor+ satellite cells reappear in close association with regenerating myofibers 7 days after muscle damage, often outside the basal lamina. Moreover, an agonist of calcitonin receptor suppressed the activation of quiescent satellite cells on myofibers in in vitro culture, suggesting that calcitonin receptor signaling plays an important role in renewal and maintenance of satellite cells. Our results show the gene expression profile of quiescent satellite cells for the first time and reveal the temporal and spatial reappearance of a satellite cell pool. Experiment Overall Design: Satellite cells and non-satellite cells were examined. Totally three types of cells (groups), the satellite cells in quiescent and activated states and the non-satellite cells, were compared. Each has 4 replicates.
Project description:The study addresses the transcriptional changes occuring during activation, proliferation and differentiation of satellite cells isolated form muscle of Mus musculus
Project description:Skeletal muscle is a post-mitotic tissue with unique plasticity. It has an extraordinary ability to adjust to changes in its physiological environment by altering its metabolic phenotype and its mass. Satellite cells are the most important myogenic progenitor cells involved in muscle regeneration and remodeling. The activation of these cells is governed by genetic programs involving complex transcriptional responses and can be involved in muscle hypertrophy adaptations. We described here gene expression variations evaluated by microarray analysis in satellite cells isolated from wild type and Magic-F1 transgenic mice, a model of skeletal muscle hypertrophy. The transcriptome analysis shows an altered gene signature in proliferating Magic-F1 satellite cells compared to controls, involving genes associated to muscle growth and vasculogenesis.
Project description:Satellite cells are resident skeletal muscle stem cells responsible for muscle maintenance and repair. In resting muscle, satellite cells are maintained in a quiescent state. Satellite cell activation induces the myogenic commitment factor, MyoD, and cell cycle entry to facilitate transition to a population of proliferating myoblasts that eventually exit the cycle and regenerate muscle tissue. The molecular mechanism involved in the transition of a quiescent satellite cell to a transit-amplifying myoblast is poorly understood. We used microarrays to detail the global program of gene expression of in vivo satellite cell activation through muscle injury and identified RNA post-transcriptional regulation as a key component of satellite cell activation. Wild type or Sdc4-/- satellite cells were FACS isolated from resting muscle or from muscle 12h and 48h following barium chloride-induced muscle injury. 5000 cell equivalents of RNA was labeled and hybridized to MOE430v2 GeneChips (Affymetrix) and scanned as per manufacturers protocol. Probeset intensities were GCRMA normalized for further analysis including UPGMA hierarchical clustering, analysis of variance (ANOVA), and fold change.
Project description:Satellite cells are responsible for the long-term regenerative capacity of adult skeletal muscle. The diminished muscle performance and regenerative capacity of aged muscle is thought to reflect progressive fibrosis and atrophy. Whether this reduction in muscle competency also involves a diminishment in the intrinsic regulation of satellite cell self-renewal remains unknown. We used microarray to identify gene expression changes underlying the marked reduction in the capacity of satellite cells to self-renew, contribute to regeneration and repopulate the niche as they age. Skeletal muscles from heterozygous Pax7-ZsGreen mice were isolated at defined stages: E17.5 (fetal - whole forelimb and hindlimb), postnatal day 21 (adolescent - hindlimb), 2-3 month old (young adult - hindlimb) and >1 year old (older adult - hindlimb) mice. ZsGreen-positive skeletal muscle satellite cells were isolated by FACS and pooled (fetal n=4, adolescent n=6, young adult n=8 and older adult n=8 mice).