Transcriptional profiling by array of U2OS cells with activated transcription factor FOXO3
ABSTRACT: Transcription factors belonging to the same transcription factor families contain very similar DNA binding domains and hence have the potential to bind to related DNA sequences. However subtle differences in binding specificities can be detected in vitro with the potential to direct specific responses in vivo. In this study the binding properties of three Forkhead transcription factors, FOXK2, FOXO3 and FOXJ3 were studied in vivo. Here we submit the gene expression component of this study. LY294002 treatment of U2OS cells which promotes FOXO3 translocation to the nucleus, and hence activation of the FOXO3 target genes.
Project description:Chromatin immunoprecipitation of FOXK2 (tagged with Flag and His tags) in U2OS cells detected by SOLiD sequencing. ***Correction March 2014: The sample “FOXK2_Dox_treated” has been renamed, it was originally named “FOXK2_rep2”. A new sample “FOXK2_rep2” has been added, with new files. It has come to our attention that one of the FOXK2 ChIP-seq replicates 'FOXK2_rep2' that we used in our paper recent paper (Ji, Z., Donaldson, I.J., Liu, J., Hayes, A., Zeef, L.A.H. and Sharrocks, A.D. (2012) The forkhead transcription factor FOXK2 promotes AP-1-mediated transcriptional regulation. Mol. Cell. Biol. 32, 385-398. doi:10.1128/MCB.05504-11) was incorrect. The replicate was actually treated with doxorubicin prior to ChIP-seq analysis resulting in the loss of many FOXK2 binding events.***
Project description:FOXO transcription factors are central regulators of longevity from worms to humans. FOXO3 – the FOXO isoform associated with exceptional human longevity – preserves adult neural stem cell pools. Here we identify FOXO3 direct targets genome-wide in primary cultures of adult neural progenitor cells (NPCs). Interestingly, FOXO3-bound sites are enriched for motifs for bHLH transcription factors and FOXO3 shares common targets with the pro-neuronal bHLH transcription factor ASCL1/MASH1 in NPCs. Analysis of the chromatin landscape reveals that FOXO3 and ASCL1 are particularly enriched at the enhancers of genes involved in neurogenic pathways. Intriguingly, FOXO3 inhibits ASCL1-dependent neurogenesis in NPCs and direct neuronal conversion in fibroblasts. FOXO3 also restrains neurogenesis in vivo. Our study identifies a genome-wide interaction between the pro-longevity transcription factor FOXO3 and the cell fate determinant ASCL1, and raises the possibility that FOXO3’s ability to restrain ASCL1-dependent neurogenesis may help preserve the neural stem cell pool. ChIP-seq profiles of two transcription factors (FOXO3 and ASCL1) and three histone marks (H3K4me1, H3K4me3 and H3K27me3) in adult mouse neural progenitor cells.
Project description:We have used an unbiased systems approach to predict that a member of the forkhead family of transcription factors, FOXO3, is a negative regulator of a subset of antiviral genes. This prediction was validated using macrophages isolated from Foxo3-null mice. We detected significantly increased transcription of a subset of interferon-stimulated genes (ISGs) under basal conditions in Foxo3-null macrophages when compared to their wild type (WT) counterparts, suggesting that FOXO3 functions as a repressor of these genes. Stimulation of Foxo3-null macrophages with poly-IC (PIC) further increased the levels of this subset of ISGs, and also revealed the transcription of additional ISGs. C57BL/6 mice were obtained from Jackson Laboratories. Foxo3-/- mice in the FVB background were obtained from MMRRC and were backcrossed to C57BL/6 mice at least 5 times to generate congenic mice. C57BL/6 Foxo3+/- heterozygotes were intercrossed to generate Foxo3-/- mice. Mice were maintained at the animal facility of the Institute for Systems Biology and used at 8-12 weeks of age. All animals were housed and handled according to the approved protocols of the University of Washington and Institute for Systems Biology's Institutional Animal Care and Use Committees. Bone marrow macrophages from wildtype and Foxo3 knock-out mice were stimulated with PIC or left untreated. 3 replicates per group.
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:FOXO transcription factors control cellular formation of reactive oxygen species (ROS), which critically contribute to cell survival and cell death in neuroblastoma. Here, we report that C10orf10, also named “Decidual Protein induced by Progesterone (DEPP)”, is a direct transcriptional target of FOXO3 in human neuroblastoma. As FOXO3-mediated apoptosis involves a biphasic ROS accumulation, we analyzed cellular ROS levels in DEPP-knockdown cells by live-cell imaging. Knockdown of DEPP prevented the primary and secondary ROS accumulation during FOXO3 activation and attenuates FOXO3-induced apoptosis, whereas its overexpression raises cellular ROS levels and sensitizes to cell death. In neuronal cells, cellular steady state ROS are mainly detoxified in peroxisomes by the enzyme CAT/catalase. As DEPP contains a peroxisomal-targeting-signal-type-2 (PTS2) sequence at its N-terminus that enables protein import into peroxisomes, we analyzed the effect of DEPP on peroxisomal function by measuring the catalase enzyme activity. Catalase activity was reduced by conditional DEPP overexpression and significantly increased in DEPP-knockdown cells. Using live cell imaging and fluorescent peroxisomal and mitochondrial probes we demonstrate that DEPP localizes to peroxisomes and mitochondria in neuroblastoma cells. The combined data indicate that DEPP reduces peroxisomal activity and thereby impairs the cellular ROS detoxification capacity and contributes to death sensitization. SH-EP, NB15 neuroblastoma cells and CCRF-CEM-C7H2 acute lymphoblastic leukemia cells were infected with the retrovirus plasmid pLIB-FOXO3(A3)-Ertm-iresNeo. Gene expression measures of samples with activated FOXO3 transcription factor (3h OHT treated) have been compared to untreated samples (0h time point). To rule out gene regulations by estrogen samples treated for 3 hours with tamoxifen have been compared to the untreated samples. Only genes that were more than two-fold regulated in the first, but not in the second comparison were defined to be FOXO3 regulated.
Project description:This SuperSeries is composed of the following subset Series: GSE36241: Identification of a FOXO3/IRF7 circuit that limits inflammatory sequelae of antiviral responses (ChIP-Seq) GSE37051: Identification of a FOXO3/IRF7 circuit that limits inflammatory sequelae of antiviral responses (expression) Refer to individual Series
Project description:Expression profiling was done of exposure to phorbol myristate acetate -PMA and FOXK2 depletion by siRNA transfection. This was done on the human osteosarcoma U2OS cell line which stably expresses FOXK2. PMA is an inducer of AP1 activity.