ChIP-seq and mRNA-seq experiment to find the direct target genes of ATF4 and CHOP
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Maureen Sartor
PROVIDER: E-GEOD-35681 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:We report the direct target genes of ATF4 and CHOP in response to endoplasim reticulum stress through next generation sequencing. By obtaining genowide sequence from chromatin immunoprecipitated DNA with anti-CHOP and anit-ATF4, we identified direct binding sites of ATF4 and CHOP in promoter regions of their target genes in mouse embrynic fibroblasts (MEFs) in response to ER stress. In addition, we obtained list of genes which are differentially regulated in Atf4 or Chop-deficient MEFs compared to the wild-type MEFs in response to ER stress. We found that genes related with unfolded protein response and protein synthesis were directly regulated by ATF4 and CHOP. Through this observation, we conclude that main role of ATF4 and CHOP as transcription factors is to enhance mRNA translation in respone to ER stress. This sutdy provide new insight of genetic network of ATF4 and CHOP in response to ER stress.
2013-04-11 | GSE35681 | GEO
Project description:Drug-induced liver injury (DILI) is an important clinical problem. Here we used a genomics approach to establish the critical drug-induced toxicity pathways that act in synergy with the pro-inflammatory cytokine tumor necrosis factor M-oM-^AM-! (TNFM-oM-^AM-!) to cause cell death of liver HepG2 cells. Transcriptomics of the cell injury stress response pathways initiated by two hepatoxicants, diclofenac and carbamazepine, revealed the endoplasmic reticulum (ER) stress/translational initiation signaling and Nrf2 antioxidant signaling as two major affected pathways, which was similar to that observed for the majority of ~80 DILI compounds in primary human hepatocytes. The ER stress was primarily related to PERK and ATF4 activation and subsequent expression of CHOP, which was all independent of TNFM-NM-1 signaling. Identical ATF4 dependent transcriptional programs were observed in primary human hepatocytes as well as primary precision cut human liver slices. Targeted RNA interference studies revealed that while ER stress signaling through IRE1M-NM-1 and ATF6 acted cytoprotective, activation of the ER stress protein kinase PERK and subsequent expression of CHOP was pivotal for the onset of drug/TNF-induced apoptosis. While inhibition of the Nrf2-dependent adaptive oxidative stress response enhanced the drug/TNF cytotoxicity, Nrf2 signaling did not affect CHOP expression. Both hepatotoxic drugs enhanced expression of the translational initiation factor EIF4A1, which was essential for CHOP expression and drug/TNFM-oM-^AM-!-mediated cell killing. Our data support a model in which enhanced drug-induced translation initiates PERK-mediated CHOP signaling in an EIF4A1 dependent manner, thereby sensitizing towards caspase-8-dependent TNF induced apoptosis. 4 biological replicates of Diclofenac and 6 biological replicates of vehicle. 46 hours after isolation, cells were exposed to either 300 M-BM-5M DCF or the solvent DMSO for 24 hours.
2014-01-22 | E-GEOD-54256 | biostudies-arrayexpress
Project description:The integrated stress response (ISR) controls cellular adaptations to nutrient deprivation, redox imbalances and ER stress. ISR genes are upregulated in stressed cells, primarily by the bZIP transcription factor ATF4 through its recruitment to cis-regulatory C/EBP:ATF response elements (CAREs) together with a dimeric partner of uncertain identity. Here we show that C/EBPγ:ATF4 heterodimers, but not C/EBPβ:ATF4 dimers, are the predominant CARE binding species in stressed cells. C/EBPγ and ATF4 associate with genomic CAREs in a mutually-dependent manner and co-regulate many ISR genes. By contrast, the C/EBP family members C/EBPβ and CHOP were largely dispensable for induction of stress genes. Cebpgâ??/â?? MEFs proliferate poorly and exhibit oxidative stress due to reduced glutathione levels and impaired expression of several glutathione biosynthesis pathway genes. Cebpgâ??/â?? mice (C57BL/6 background) display reduced body size and microphthalmia, similar to ATF4-null animals. In addition, C/EBPγ-deficient newborns die from atelectasis and respiratory failure which can be mitigated by in utero exposure to the anti-oxidant, N-acetyl-cysteine. Cebpgâ??/â?? mice on a mixed strain background show improved viability but, upon aging, develop significantly fewer malignant solid tumors compared to WT animals. Our findings identify C/EBPγ as a novel anti-oxidant regulator and an obligatory ATF4 partner that controls redox homeostasis in normal and cancerous cells. WT, Atf4-/-, and Cebpg-/- MEFs (passage 3) were cultured under normal and AAD conditions. RNA from each treatment condition was collected in triplicate for hybrization on Affymetrix Mouse Genome 430 2.0 microarrays.
2015-11-19 | E-GEOD-75150 | biostudies-arrayexpress
Project description:To further development of our miRNA expression approach to ER stress, we have employed miRNA microarray expression profiling as a discovery platform to identify ER stress-responsible ones. Mouse embryonic fibroblasts (MEFs) deficient in a ER stress mediator ATF4 were treated with tunicamycin for 12 or 24 hrs. miRNAs responsible for tunicamycin-treatment for 12hrs in ATF4-dependent manner were extracted. Among them, expression of three miRNAs (miR-193b, miR-423-5p, miR-199a-3p) was quantified in the RNA samples from the same as the microarray by real-time PCR. Mouse embryonic fibroblasts (MEFs) deficient in a ER stress mediator ATF4 were treated with 2ug/mL tunicamycin for 12 or 24 hrs. Two independent experiments were performed at each time (untreated, 12 or 24 hrs). miRNAs responsible for tunicamycin-treatment for 12hrs in ATF4-dependent manner were extracted.
2015-01-18 | E-GEOD-35175 | biostudies-arrayexpress
Project description:During reprogramming of fibroblasts into cardiomyocyte-like cells by overexpression of transcription factors, GATA4, Hand2, Mef2C and Tbx5 (GHMT), H3K4Me2, an active histone code, shifts from fibroblast-exclusive peaks to cardiomyocyte-exclusive peaks. Important cardiac genes are gradually marked by this active histone marker. Mouse embryonic fibroblasts (MEFs) and neonatal mouse ventricular cardiomyocytes (NMVMs) represent fibroblasts and cardiomyocytes, respectively. Chromatins harvested from MEFs infected with retroviruses carrying GHMT at day 3, day 5, day 7 post-viral infection were prepared for immunoprecipitation.
2015-07-28 | E-GEOD-71392 | biostudies-arrayexpress
Project description:The integrated stress response (ISR) controls cellular adaptations to nutrient deprivation, redox imbalances and ER stress. ISR genes are upregulated in stressed cells, primarily by the bZIP transcription factor ATF4 through its recruitment to cis-regulatory C/EBP:ATF response elements (CAREs) together with a dimeric partner of uncertain identity. Here we show that C/EBPγ:ATF4 heterodimers, but not C/EBPβ:ATF4 dimers, are the predominant CARE binding species in stressed cells. C/EBPγ and ATF4 associate with genomic CAREs in a mutually-dependent manner and co-regulate many ISR genes. By contrast, the C/EBP family members C/EBPβ and CHOP were largely dispensable for induction of stress genes. Cebpgâ/â MEFs proliferate poorly and exhibit oxidative stress due to reduced glutathione levels and impaired expression of several glutathione biosynthesis pathway genes. Cebpgâ/â mice (C57BL/6 background) display reduced body size and microphthalmia, similar to ATF4-null animals. In addition, C/EBPγ-deficient newborns die from atelectasis and respiratory failure which can be mitigated by in utero exposure to the anti-oxidant, N-acetyl-cysteine. Cebpgâ/â mice on a mixed strain background show improved viability but, upon aging, develop significantly fewer malignant solid tumors compared to WT animals. Our findings identify C/EBPγ as a novel anti-oxidant regulator and an obligatory ATF4 partner that controls redox homeostasis in normal and cancerous cells. Evaluation of genomic binding of 2 bZIP transcription factors under amino acid deprivation conditions in mouse embryonic fibroblasts
2015-11-19 | E-GEOD-75165 | biostudies-arrayexpress
Project description:Drug-induced liver injury (DILI) is an important clinical problem. Here we used a genomics approach to establish the critical drug-induced toxicity pathways that act in synergy with the pro-inflammatory cytokine tumor necrosis factor (TNF) to cause cell death of liver HepG2 cells. Transcriptomics of the cell injury stress response pathways initiated by two hepatoxicants, diclofenac and carbamazepine, revealed the endoplasmic reticulum (ER) stress/translational initiation signaling and Nrf2 antioxidant signaling as two major affected pathways, which was similar to that observed for the majority of ~80 DILI compounds in primary human hepatocytes. The ER stress was primarily related to PERK and ATF4 activation and subsequent expression of CHOP, which was all independent of TNFM-NM-1 signaling. Identical ATF4 dependent transcriptional programs were observed in primary human hepatocytes as well as primary precision cut human liver slices. Targeted RNA interference studies revealed that while ER stress signaling through IRE1M-NM-1 and ATF6 acted cytoprotective, activation of the ER stress protein kinase PERK and subsequent expression of CHOP was pivotal for the onset of drug/TNF-induced apoptosis. While inhibition of the Nrf2-dependent adaptive oxidative stress response enhanced the drug/TNF cytotoxicity, Nrf2 signaling did not affect CHOP expression. Both hepatotoxic drugs enhanced expression of the translational initiation factor EIF4A1, which was essential for CHOP expression and drug/TNF-mediated cell killing. Our data support a model in which enhanced drug-induced translation initiates PERK-mediated CHOP signaling in an EIF4A1 dependent manner, thereby sensitizing towards caspase-8-dependent TNF induced apoptosis. Liver slices (diameter 4 mm, thickness 250 M-BM-5m) were pre-incubated at 37M-BM-0C for 1h individually in a well containing 1.3 ml WilliamsM-bM-^@M-^Y medium E with glutamax-1 (Gibco, Paisley, UK), supplemented with 25 mM D-glucose and 50 M-BM-5g/ml gentamicin (Gibco, Paisley, UK) (WEGG medium) in a 12-well plate with shaking (90 times/min) under saturated carbogen atmosphere.
2014-01-22 | E-GEOD-54255 | biostudies-arrayexpress
Project description:Drug-induced liver injury (DILI) is an important clinical problem. Here we used a genomics approach to establish the critical drug-induced toxicity pathways that act in synergy with the pro-inflammatory cytokine tumor necrosis factor (TNF) to cause cell death of liver HepG2 cells. Transcriptomics of the cell injury stress response pathways initiated by two hepatoxicants, diclofenac and carbamazepine, revealed the endoplasmic reticulum (ER) stress/translational initiation signaling and Nrf2 antioxidant signaling as two major affected pathways, which was similar to that observed for the majority of ~80 DILI compounds in primary human hepatocytes. The ER stress was primarily related to PERK and ATF4 activation and subsequent expression of CHOP, which was all independent of TNFα signaling. Identical ATF4 dependent transcriptional programs were observed in primary human hepatocytes as well as primary precision cut human liver slices. Targeted RNA interference studies revealed that while ER stress signaling through IRE1α and ATF6 acted cytoprotective, activation of the ER stress protein kinase PERK and subsequent expression of CHOP was pivotal for the onset of drug/TNF-induced apoptosis. While inhibition of the Nrf2-dependent adaptive oxidative stress response enhanced the drug/TNF cytotoxicity, Nrf2 signaling did not affect CHOP expression. Both hepatotoxic drugs enhanced expression of the translational initiation factor EIF4A1, which was essential for CHOP expression and drug/TNF-mediated cell killing. Our data support a model in which enhanced drug-induced translation initiates PERK-mediated CHOP signaling in an EIF4A1 dependent manner, thereby sensitizing towards caspase-8-dependent TNF induced apoptosis. We sought to determine the effect of co-exposure of certain drugs associated with idiosyncratic DILI with the cytokine TNFalpha to mimic drug exposure with inflammation signaling in HepG2 cells Human hepatoma HepG2 cells were obtained from American Type Culture Collection (ATCC, Wesel, Germany), cultured in DMEM supplemented with 10% (v/v) FBS, 25 U/mL penicillin and 25 µg/mL streptomycin and used for experiments between passage 5 and 20.
2014-01-22 | E-GEOD-54254 | biostudies-arrayexpress
Project description:To further development of our mRNA or lincRNA expression approach to ER stress, we have employed whole genome microarray expression profiling as a discovery platform to identify ER stress-responsible genes. Mouse embryonic fibroblasts (MEFs) deficient in each ER stress mediator (XBP1, ATF4, ATF6a or ATF6b) were treated with tunicamycin for 12 or 24 hrs. Genes responsible for tunicamycin in each mediator-dependent manner were extracted and categorized by Gene Ontology. Among them, expression of five ER-related genes (Derl1, Ssr3, Magt1, Bet1 and Mcfd2) was quantified in the RNA samples from COS7 cells by real-time PCR, confirming existence of similar mechanisms of trancriptional activation in ER stress by tunicamycin treatment. Mouse embryonic fibroblasts (MEFs) deficient in each ER stress mediator (XBP1, ATF4, ATF6a or ATF6b) were treated with 2ug/mL tunicamycin for 12 or 24 hrs. Two independent experiments were performed for each mediator-deficient MEF at each time (untreated, 12 or 24 hrs). Genes responsible for tunicamycin in each mediator-dependent manner were extracted and categorized by Gene Ontology in GeneRanker program of Genomatix platform.
2015-01-18 | E-GEOD-35173 | biostudies-arrayexpress
Project description:Drug-induced liver injury (DILI) is an important clinical problem. Here we used a genomics approach to establish the critical drug-induced toxicity pathways that act in synergy with the pro-inflammatory cytokine tumor necrosis factor (TNF) to cause cell death of liver HepG2 cells. Transcriptomics of the cell injury stress response pathways initiated by two hepatoxicants, diclofenac and carbamazepine, revealed the endoplasmic reticulum (ER) stress/translational initiation signaling and Nrf2 antioxidant signaling as two major affected pathways, which was similar to that observed for the majority of ~80 DILI compounds in primary human hepatocytes. The ER stress was primarily related to PERK and ATF4 activation and subsequent expression of CHOP, which was all independent of TNFα signaling. Identical ATF4 dependent transcriptional programs were observed in primary human hepatocytes as well as primary precision cut human liver slices. Targeted RNA interference studies revealed that while ER stress signaling through IRE1α and ATF6 acted cytoprotective, activation of the ER stress protein kinase PERK and subsequent expression of CHOP was pivotal for the onset of drug/TNF-induced apoptosis. While inhibition of the Nrf2-dependent adaptive oxidative stress response enhanced the drug/TNF cytotoxicity, Nrf2 signaling did not affect CHOP expression. Both hepatotoxic drugs enhanced expression of the translational initiation factor EIF4A1, which was essential for CHOP expression and drug/TNF-mediated cell killing. Our data support a model in which enhanced drug-induced translation initiates PERK-mediated CHOP signaling in an EIF4A1 dependent manner, thereby sensitizing towards caspase-8-dependent TNF induced apoptosis.
2014-01-22 | GSE54256 | GEO