Project description:This SuperSeries is composed of the following subset Series: GSE16992: Expression Profiling of Early Myogenesis - Affymetrix Dataset GSE17038: Expression Profiling of Early Myogenesis - Illumina Dataset Refer to individual Series
Project description:Myogenesis is governed by signalling networks whose regulations are tightly controlled in a time-dependent manner. While different protein kinases have been identified to regulate various aspects of myogenesis, knowledge on the global signalling networks and their downstream substrates during myogenesis remains incomplete. Here, we map the myogenic differentiation of C2C12 cells using mass spectrometry (MS)-based phosphoproteomics and proteomics. From these data, we infer global kinase activity and predict substrates of key kinases that are involved in myogenesis. We found that multiple mitogen-activated protein kinases (MAPKs) mark the initial wave of signalling cascades. Further phosphoproteomic and proteomic profiling with MAPK1/3 and MAPK8/9 specific inhibitions unveil their shared and distinctive roles on myogenesis.
Project description:Modulating the number of muscle stems cells, called satellite cells, during early postnatal development produces long-term effects on muscle growth. We tested the hypothesis that high expression levels of the anti-aging protein Klotho in early postnatal myogenesis increase satellite cell numbers by influencing the epigenetic regulation of genes that regulate myogenesis. Our findings show that elevated klotho expression caused a transient increase in satellite cell numbers and slowed muscle fiber growth, followed by a period of accelerated muscle growth that resulted in larger fibers. Klotho also transcriptionally down-regulated the H3K27 demethylase Jmjd3, increased H3K27 methylation and decreased expression of genes in the canonical Wnt pathway, which was associated with a significant delay in muscle differentiation. In addition, Klotho stimulation and subsequent Jmjd3 down-regulation produced similar but not additive reductions in the expression of Wnt4, Wnt9a and Wnt10a in myogenic cells, indicating that inhibition occurred through a common pathway. Together, our results identify a novel pathway through which Klotho influences myogenesis by reducing expression of Jmjd3, leading to reductions in the expression of Wnt genes and inhibition of canonical Wnt signaling.
Project description:To predict Rp58-regulated gene involved in myogenesis, RNA profiling experiments were performed, comparing RNA derived from C2C12 with or without expressing shRNA for Rp58. As a result, 271 genes were upregulated in C2C12 stably expressing shRNA-Rp58 cells compared with control C2C12 cells. As Rp58 is repressor in C2C12, we hypothesized that Rp58 regulates gene cluster which expression is downregulated in accordance with Rp58 expression and myogenesis progression. In this regard, we also characterized dynamic gene expression patterns during myogenesis by microarray at 4 different stage (GM, day 0, 2, 4) of C2C12 myogenesis assays and found that 399 genes expression is characterized as downregulation pattern during myogenesis. Importantly, this down regulation gene set and upregulated genes by shRNA for Rp58 were highly overlapped. Keywords: time course, shRNA
Project description:This SuperSeries is composed of the following subset Series: GSE34906: Genetic and epigenetic determinants of neurogenesis and myogenesis [ChIP-seq] GSE34907: Genetic and epigenetic determinants of neurogenesis and myogenesis [expression profiling] Refer to individual Series
Project description:Tamoxifen, a selective estrogen receptor modulator (SERM), is commonly used in the treatment of hormone-responsive cancers. The effects of tamoxifen in anabolic tissues harboring estrogen-receptors, such as skeletal muscle, are poorly understood. As estrogen and estrogen receptors play an important role in skeletal muscle development and repair, we hypothesize that tamoxifen may have specific effects on myogenesis, the developmental process underlying muscle cells differentiation and repair. Myogenesis is characterized by fine-tuned changes in protein expression as embryonic myoblasts and adult satellite cells transition from pluripotent stem cells to multinucleated, contractile muscle fibers: we undertake a quantitative proteomic analysis of tamoxifen-induced changes in developing skeletal muscle cells which we expect may also shed light on the effect of tamoxifen on muscle repair.
We report a tandem mass-tag (TMT) approach to tamoxifen-treated myogenesis in C2C12 cells, a well-characterized model of in vitro murine skeletal muscle differentiation. A longitudinal analysis of >10,000 proteins identified in C2C12 myogenesis revealed a novel subset of 1,239 myogenically-regulated proteins. This set of regulatory proteins clustered into five distinct longitudinal expression trends which significantly overlap those obtained in similar analyses performed in human myocytes. A longitudinal analysis of myogenesis in the presence of tamoxifen, when contrasted with a similar analysis in untreated myogenesis finds that while the vast majority of myogenically-regulated proteins were unaffected by tamoxifen treatment, specific pathways and networks are affected. We document a specific functional enrichment for adiponectin-signaling, whereby a set of 198 proteins were differentially expressed relative to controls at one or more stages of myogenesis, the majority of which were involved in steroid biosynthesis, lipid storage and/or metal ion homeostasis. Interestingly, the only protein that was differentially expressed in the tamoxifen-treated cells at every stage of myogenesis was metallothionein-1 (MT1). Elevated levels of MT1 have been correlated with tamoxifen resistance and increased patient mortality and relapse in breast cancer, as well as with cachexia and muscle atrophy in rodent models. Increased MT1 expression levels may contribute to the musculoskeletal effects reported by patients undergoing tamoxifen treatment. Finally, we present a powerful, self-validating pipeline for analyzing the total proteomic response to in vitro treatment across every stage of muscle cells development which can be easily adapted to study the effects of other drugs on myogenesis.