MiRNA expression profiling during C2C12 myogenesis
ABSTRACT: This study profiled the expression of miRNA during myogenesis of the C2C12 mouse myoblast cell line. Cells were harvest at different stages during myogenesis including proliferating, confluence, 1 day post-differentiation induction, 2 day post-differentiation induction and 4 days post-differentiation induction. Keywords: time course This experiment was a reference design miRNA microarray where all time points were compared to a pooled proliferating C2C12 sample, made up of 4 proliferating biological replicates. Each time point had four bioloigcal replicates of which two were labelled with Cy3 and two were labelled with Cy5.
Project description:This study profiled the expression of miRNA during myogenesis of the C2C12 mouse myoblast cell line. Cells were harvest at different stages during myogenesis including proliferating, confluence, 1 day post-differentiation induction, 2 day post-differentiation induction and 4 days post-differentiation induction. Keywords: time course Overall design: This experiment was a reference design miRNA microarray where all time points were compared to a pooled proliferating C2C12 sample, made up of 4 proliferating biological replicates. Each time point had four bioloigcal replicates of which two were labelled with Cy3 and two were labelled with Cy5.
Project description:ChIP-seq analysis of LSD1 in C2C12 cells. We found that LSD1 directly regulates the expression of fiber and metabolism genes during myogenesis. Results provide insight into the molecular mechanisms of myogenesis. Overall design: Examination of LSD1/DNA interaction in C2C12 myoblasts 48 h post-differentiation.
Project description:ChIP-seq analysis of LSD1 in C2C12 cells. We found that LSD1 directly regulates the expression of fiber and metabolism genes during myogenesis. Results provide insight into the metabolic prgramming mechanisms of myogenesis. Overall design: Examination of LSD1/DNA interaction in C2C12 myoblasts 48 h (day 2) and 120 h (day 5) post-differentiation.
Project description:Myogenesis is a complex process required for skeletal muscle formation during embryonic development and for regeneration and growth of myofibers in adults. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) play key roles in regulating cell fate decision and function in various tissues. However, the role of lncRNAs in the regulation of myogenesis remains poorly understood. In this study, we identified a novel muscle-enriched lncRNA called "Myolinc (AK142388)", which we functionally characterized in the C2C12 myoblast cell line. Myolinc is predominately localized in the nucleus, and its levels increase upon induction of the differentiation. Knockdown of Myolinc impairs the expression of myogenic regulatory factors and formation of multinucleated myotubes in cultured myoblasts. Myolinc also regulates the expression of Filip1 in a cis-manner. Similar to Myolinc, knockdown of Filip1 inhibits myogenic differentiation. Furthermore, Myolinc binds to TAR DNA-binding protein 43 (TDP-43), a DNA/RNA-binding protein that regulates the expression of muscle genes (e.g. Acta1 and MyoD). Knockdown of TDP-43 inhibits myogenic differentiation. We also show that Myolinc-TDP-43 interaction is essential for the binding of TDP-43 to the promoter regions of muscle marker genes. Finally, we show that silencing of Myolinc inhibits skeletal muscle regeneration in adult mice. Altogether, our study identifies a novel lncRNA that controls key regulatory networks of myogenesis. Overall design: Using C2C12 cells, we performed microarray experiments (n=2) for each time point and condition. “Day_2” dataset: siMyolinc-knockdown C2C12 cells on day 2 of the differentation were compared to C2C12 cells transfected with siRNA against scramble control (siScr) and differentiated for 2 days. “Undiff-Day_2” dataset: siMyolinc-knockdown C2C12 cells on day 2 of the differentation were compared to normally cultured C2C12 cells in the growth medium (“Undiff”), one and two days after the differentiation (“Day_1” and “Day_2”, respectively).
Project description:Skeletal muscle contains long multinucleated and contractile structures known as muscle fibers, which arise from the fusion of myoblasts into nucleated myotubes during myogenesis. The myogenic regulatory factor (MRF) MYF5 is the earliest to be expressed during myogenesis and functions as a transcription factor in muscle progenitor cells (satellite cells) and myocytes. In mouse C2C12 myocytes, MYF5 is implicated in the initial steps of myoblast differentiation into myotubes. Ribonucleoprotein immunoprecipitation (RIP) analysis showed that MYF5 bound a subset of myoblast mRNAs; prominent among them was Ccnd1 mRNA, which encodes the key cell cycle regulator CCND1 (Cyclin D1). Biotin-RNA pulldown, UV-crosslinking, and gel shift experiments indicated that MYF5 was capable of binding the 3' untranslated region (UTR) and the coding region (CR) of Ccnd1 mRNA. MYF5 silencing in proliferating growing myoblasts revealed that and MYF5 promoted CCND1 translation, and it also modestly increased transcription of Ccnd1 mRNA. Importantly, silencing MYF5 reduced myoblast growth as well as differentiation of myoblasts into myotubes, while overexpressing MYF5 in C2C12 cells upregulated CCND1 expression. We propose that MYF5 enhances early myogenesis in part by coordinately elevating Ccnd1 transcription and Ccnd1 mRNA translation. Four replicates were utilized from either Control (IgG) or MYF5-immunoprecipitated RNA samples from C2C12 cells growing in either growth medium (GM) or differentiation medium (DM) for a total of sixteen samples.
Project description:Mitogen activated protein kinase (MAPK) signaling regulates differentiation of many cell types. During myogenesis in particular, p38a MAPK (MAPK14) phosphorylates multiple transcriptional regulators to modulate muscle-specific gene expression. Among the p38a MAPK modulated genes is the muscle-specific transcriptional regulator Myogenin (Myog) that is also essential to complete the muscle differentiation program, and while it is known that both p38a MAPK and Myog are critically required for myogenesis, the individual contribution of each of these proteins is poorly defined. Here we show that Myog expression (in the absence of p38a MAPK signaling) is sufficient to establish expression of many late markers of muscle differentiation and to mediate cell migration. However, Myog expression alone did not led to the formation of multinucleated muscle cells, highlighting a critical role for p38a MAPK in myoblast fusion. Using comparative microarray analysis we identified p38a MAPK-dependent genes that are not regulated by Myog We generated a stable C2C12-derived cell line (C2i-Myog) that expresses a Doxycycline (Dox)-inducible cDNA encoding Flag-tagged Myog. In this system, the chemical induction of exogenous Myog (Dox) combined with the pharmacological inhibition of p38a/b MAPK signaling by SB203580 (SB) would allow us to assess the functional contribution of these two pathways during myogenesis
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. Experiment Overall Design: C2C12 murine skeletal muscle cells were purchased from American Type Experiment Overall Design: culture Collection (ATCC). These cells were mainteined in GM (DMEM Experiment Overall Design: supplemented with 10% FBS). Cells were grown in GM and after reaching Experiment Overall Design: counfluence, the medium was switched to DM (DMEM supplemented with 2% hourse serum) and further incubated. The medium was changed every 2 days. Culture was performed by using within five passages cells. For the experiment of shRNA for Rp58, transfection was performed by using Lipofectamin 2000 (Invitrogen). Stable transfectants were obtained by selection of the transfected C2C12 cells for two weeks. Experiment Overall Design: Microarray analysis - RNA was isolated as described from C2C12, and cRNA was synthesized. 10 ug of cRNA were hybridized to Affymetrix mouse 430 2.0 arrays. Intensity values were quantified using RMA algorithm. Experiment Overall Design: MAPPFinder (www.genmapp.org) was used to integrate expression data with known pathways.
Project description:ChIP-seq analysis of methylated H3K4 in LSD1-inhibited C2C12 cells. We found that LSD1 widely regulates the methylation levels of H3K4. Results provide insight into the molecular mechanisms of regulation of histone modification in myogenesis. Overall design: Examination of H3, H3K4me1, H3K4me2 and H3K4me3/DNA interaction in LSD1-inhibited C2C12 myoblasts 48 h (day 2) post-differentiation.
Project description:Analysis of Early Myogenesis Reveals an Extensive Set of Transcriptional Regulators Whose Knock-down Can Inhibit Differentiation Myogenesis is a tightly controlled process involving the transcriptional activation and repression of thousands of genes. Although many components of the transcriptional network are known for the later phases of myogenesis, relatively little work has described the transcriptional landscape within the first 24 hours, when myoblasts commit to differentiate. Through dense temporal sampling of differentiating C2C12 myoblasts, we identify 266 transcriptional regulators (TRs) whose expression is altered within the first 12 hours of myogenesis. A high-content shRNA screen of 76 TRs involving 427 stable lines identified 48 genes whose knockdown significantly inhibits differentiation of C2C12 myoblasts. These include known regulators of myogenesis (Myod1, Myog and Myf5), as well as 26 regulators not previously associated with the process. Of the TRs differentially expressed within the first 24 hours, two-thirds inhibited differentiation when knocked down. Surprisingly, a similar proportion (67%) of shRNAs targeting TRs whose expression did not change during differentiation also inhibited myogenesis, suggesting that both stably and differentially expressed TRs are essential for this complex differentiation program. This implies that microarray-based approaches that concentrate functional validation studies on differentially-expressed genes will fail to identify many genes that are critically implicated in complex biological processes. C2C12 myoblasts were differentiated into myotubes and sampled at various time points for gene expression measurement on MOE-430v2 chips. Cells grown in separate plates were harvested at 14 different time points: t_-24h, t_0h, t_0.5h, t_1h, t_1.5h, t_2h, t_3h, t_6h, t_9h, t_12h, t_24h, t_48h, t_96h, t_144h. Cells were also pre-treated with 50uM cycloheximide 1 hour prior to inducing differentiation and harvested at two time points: t_chx_1h, t_chx_3h. All harvests were performed in triplicate using growths from successive passages.
Project description:During muscle differentiation, myogenesis sepcific genes are differentially regulated, including Lamins that function at least in maintenance of nuclear architecture and regulation of gene expression. We used microarrays to detail the global changes of gene expression in lamins and nuclear envelope assoicated proteins during myogenesis. Experiment Overall Design: C2C12 were cultured either in 20% serum (undifferentiated) or in 2% horse serum (differentiated). Differentiated C2C12 cells were harvested on day 6 after induction of myogenesis in low serum. Affymetirx microarray raw data were further processed by GCRMA to globally normalized signal values and then subjected to analysis of Bayesian regularized t-test. Gene expression, that has a p-value less than 0.05 in the t-test and has more than 1.5 fold change, was considered siginificant.