ABSTRACT: C2C12 cells are mouse skeletal muscle cells. These cells were transfected with shRNA against FoxO1, FoxO3, and FoxO4. FoxO1, FoxO3, and FoxO4 are the known paralogues expressed in this cell line.
Project description:C2C12 cells are mouse skeletal muscle cells. These cells were transfected with shRNA against FoxO1, FoxO3, and FoxO4. FoxO1, FoxO3, and FoxO4 are the known paralogues expressed in this cell line. C2C12 cells are transfected with shRNA against FoxO1, FoxO3, and FoxO4, respectively. Colonies were selected for the best depletion of the target FoxOs, respectively. Cells were grown in DMEM medium. Total RNA was extracted from each line. Microarray analysis was performed by following the Affymetrix protocols. The data were analyzed by GCOS system. The target genes that we are interested in were further confirmed by qRT-PCR, reporter assay, and other biochemical and molecular biology assays.
Project description:To investigate the role of FoxO transcription factors as mediators of hematopoietic stem cell resistance to oxidative stress. Experiment Overall Design: Study the effect of the deficiency of FoxO1, FoxO3, and FoxO4 in murine bone marrow hematopoietic stem cells and myeloid progenitors on expression of genes involved in reactive oxygen species (ROS) metabolism.
Project description:To identify novel transcriptional targets of beta-catenin and FoxO1 and FoxO3 in renal epithelial cells, we used conditionally immortalized murine proximal tubule (PT) cells (these cells, from Tgfbr2floxed mice, are described in detail in manuscript PMID: 23160515 in which Leslie Gewin is first author, JASN 2012). PT cells were either treated with Wnt3a (to activate beta-catenin) or the control diluting buffer, H2O2 to induce oxidative stress, and some were transfected with FoxO1, FoxO3, FoxO1 and 3, or scramble siRNA prior to Wnt and H2O2 treatment.
Project description:The mammalian FoxO transcription factors - FoxO1, FoxO3, FoxO4 - function in the nucleus to direct transcription of specific gene targets governing cellular survival, proliferation, metabolism, differentiation and oxidative defense. Activation of PI3K by extracellular growth factors leads to AKT-mediated phosphorylation of FoxO1, FoxO3 and FoxO4, resulting in their sequestration in the cytoplasm such that they are unable to regulate their gene targets. Our study identified FoxOs as novel tumor suppressors in kidney cancer (Gan et al, 2010, Cancer Cell). To understand the tumor suppression function of FoxOs in kidney cancer cells, we performed gene expression profiling in human kidney cancer cells upon FoxO1 or FoxO3 reactivation in order to identify the key transcriptomic alterations mediating FoxO tumor suppression function in kidney cancer cells. We generated RCC4 and UMRC2 cell lines (two human kidney cancer cells with low endogenous FoxO1 and FoxO3 expression) with stable expression of FoxO1(TA)ERT2 or FoxO3(TA)ERT2 construct, which expressed a fusion protein consisting of FoxO(TA) (containing three Ser/Thr AKT phosphorylation sites mutated to alanine) fused to the T2-modified estrogen receptor (ERT2) moiety. We documented that the FoxO(TA)ERT2 fusion protein sequestered FoxO(TA) in the cytoplasm and that 4OHT treatment resulted in rapid translocation of FoxO(TA)ERT2 into the nucleus. We also established stable cell lines with ERT2 expression as control cell lines. (For simplicity, ERT2, FoxO1(TA)ERT2 and FoxO3(TA)ERT2 cell lines will be referred to as EV (empty vector), FoxO1 and FoxO3, respectively, hereafter). We then conducted comparative transcriptome analysis (using the Human Genome U133 Plus 2.0 Array) of EV, FoxO1, or FoxO3-expressing RCC4 and UMRC2 cells at 12 hours with or without 100 nm 4OHT treatment (cultured in DMEM+10% FBS with puromycin selection). To enrich for more proximal actions of FoxO, we selected the 12 hour time point as time course studies revealed dramatic transcriptional changes of known FoxO targets (such as Cyclin D1), yet no discernable cellular phenotypes (apoptosis and cell cycle arrest). We generated 4 transcriptome datasets: FoxO1 RCC4, FoxO3 RCC4, FoxO1 UMRC2, and FoxO3 UMRC2 (by comparing transcriptome data with or without 4OHT treatment), and normalized these transcriptome data against 4OHT-treated EV cells, which show modest 4OHT-induced transcriptional changes.
Project description:The mammalian FoxO transcription factors - FoxO1, FoxO3, FoxO4 - function in the nucleus to direct transcription of specific gene targets governing cellular survival, proliferation, metabolism, differentiation and oxidative defense. Activation of PI3K by extracellular growth factors leads to AKT-mediated phosphorylation of FoxO1, FoxO3 and FoxO4, resulting in their sequestration in the cytoplasm such that they are unable to regulate their gene targets. Our study identified FoxOs as novel tumor suppressors in kidney cancer (Gan et al, 2010, Cancer Cell). To understand the tumor suppression function of FoxOs in kidney cancer cells, we performed gene expression profiling in human kidney cancer cells upon FoxO1 or FoxO3 reactivation in order to identify the key transcriptomic alterations mediating FoxO tumor suppression function in kidney cancer cells.
Project description:C2C12 mouse myoblasts were transduced with either PAX3-FOXO1 expression vector (P3F-C2C12), a system that is commonly used to study the more aggressive alveolar rhabdomyosarcoma subtype, or empty vector (Ctrl-C2C12). Exosomes were isolated from both cell lines by differential centrifugation, and exosomal markers were characterized by western blot. Then, the Affymetrix GeneChip miRNA 3.0 array was used to identify the miRNA content of the extracted exosomes where the differentially deregulated miRNA (either enriched or depleted) in P3F-C2C12 exosomes were determined relative to Ctrl-C2C12 exosomes. Results showed that PAX3-FOXO1 fusion gene alters the content of exosomes and that the enriched miR-486-5p is a downstream effector of PAX3-FOXO1 in mediating the oncogenic effects of exosome-mediated paracrine signaling in this setting.
Project description:The PI3K-PKB/c-akt-FOXO signalling network provides a major intracellular hub for regulation of cell proliferation, survival and stress resistance1. Here we report a novel function for FOXO transcription factors in regulating autophagy through modulation of intracellular glutamine levels. To identify novel transcriptional targets of this module we performed an unbiased microarray analysis after conditional activation of the key components PI3K, PKB, FOXO3 and FOXO4. Utilising this global pathway approach we identified glutamine synthetase (GS) as being transcriptionally regulated by PI3K-PKB-FOXO signalling. FOXO-mediated increase in GS expression specifically induced glutamine production independently of cell type, and this was evolutionary conserved. FOXO activation resulted in mTOR inhibition by preventing the translocation of mTOR to lysosomal membranes, which was dependent on GS activity. Increased GS activity resulted in increased autophagosome turnover as measured by LC3 lipidation, p62 degradation, and confocal imaging of LC3, p62, WIPI-1, ULK2 and Atg12. Inhibition of FOXO3-mediated autophagy resulted in increased apoptosis, suggesting that the induction of autophagy by FOXO3-mediated upregulation of GS is important for cellular survival. These findings reveal a novel signalling network that can directly modulate autophagy through regulation of glutamine metabolism. conditional activation of foxo3 and foxo4 were followed in a timeseries. Each timepoint consists of 4 independent replicates, labeled with either cy3 or cy5 and put on array against time0 as reference.
Project description:The establishment of C2C12 cell line with knockout of TAOK1 expression using CRISPR/Cas9 system. C2C12 cells with TAOK1 knockout were designated as C2C12-TAOK1-KO, while those transfected with an empty vector served as the control group (C2C12-Mock), non-transfected cells served as the blank group (C2C12-Blank). The C2C12-Blank, C2C12-Mock and C2C12-TAOK1-KO cells (10000 cells/mL) were seeded into 100 mm cell culture dishes and induced to differentiation into myotubes. Then, cells were obtained by trypsin digestion and centrifugation. Samples from three independent experiments were collected.
Project description:Effect of FOXO knockdown on E2F1-mediated transcription U2OS cells stably expressing ER-E2F1 were infected with two different lentiviruses both targeting FOXO1 and FOXO3 or control virus encoding scrambled sequence. Twenty four hours post infection medium was replaced to serum-free DMEM for 24 hours. Then medium was replaced to serum-free DMEM with or without 20 nM 4-hydroxy tamoxifen for 6 hours.
Project description:We evaluate the effects of CNN3 on myogenesis and further explored its potential molecular mechanisms. C2C12 cells were transfected with siRNA CNN3 and its NC control siRNA. Total mRNA was extracted from cells using TRIZOL reagent in accordance with the manufacturer’ protocol. And transcriptomes of CNN3 gene silenced C2C12 cells was detected by RNA-Seq.