Elevated Nrf2 response in TrxR1/Gsr-null livers
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE124445 | GEO | 2019/05/01
REPOSITORIES: GEO
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Project description:Genetic disruption of Gsr in mouse elicits only subtle changes in the liver transcriptome. Transcriptome analysis of Gsr-null livers was performed to further our understanding of pathways that may compensate for loss of Gsr, one of the two NADPH-dependent cytosolic disulfide reductases.
2019-05-01 | GSE124444 | GEO
Project description:Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that induces a battery of cytoprotective genes in response to oxidative/electrophilic stress. Kelch-like ECH associating protein 1 (Keap1) sequesters Nrf2 in the cytosol. The purpose of this study was to investigate the role of Nrf2 in regulating the mRNA of genes encoding drug metabolizing enzymes and xenobiotic transporters. Microarray analysis was performed in livers of Nrf2-null, wild-type, Keap1-knockdown mice with increased Nrf2 activation, and Keap1-hepatocyte knockout mice with maximum Nrf2 activation. In general, Nrf2 did not have a marked effect on uptake transporters, but the mRNAs of organic anion transporting polypeptide 1a1, sodium taurocholate cotransporting polypeptide, and organic anion transporter 2 were decreased with Nrf2 activation. The effect of Nrf2 on cytochrome P450 (Cyp) genes was minimal, with only Cyp2a5, Cyp2c50, Cyp2c54, and Cyp2g1 increased, and Cyp2u1 decreased with enhanced Nrf2 activation. However, Nrf2 increased mRNA of many other phase-I enzymes, such as aldo-keto reductases, carbonyl reductases, and aldehyde dehydrogenase 1. Many genes involved in phase-II drug metabolism were induced by Nrf2, including glutathione S -transferases, UDP- glucuronosyltransferases, and UDP-glucuronic acid synthesis enzymes. Efflux transporters, such as multidrug resistance-associated proteins, breast cancer resistant protein, as well as ATP-binding cassette g5 and g8 were induced by Nrf2. In conclusion, Nrf2 markedly alters hepatic mRNA of a large number of drug metabolizing enzymes and xenobiotic transporters, and thus Nrf2 plays a central role in xenobiotic metabolism and detoxification. We used microarrays to detail the global programme of gene expression in response to Nrf2 activation and identified distinct classes of up- and down-regulated genes. process. Gene expression in livers of Nrf2-null, WT, Keap1-KD, and Keap1-HKO mice was determined using Affymetrix Mouse 430.20 arrays by the KUMC Microarray Core Facility. Biological cRNA replicates (n=3) of each genotype were hybridized to an individual array.
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Project description:Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that induces a battery of cytoprotective genes in response to oxidative/electrophilic stress. Kelch-like ECH associating protein 1 (Keap1) sequesters Nrf2 in the cytosol. The purpose of this study was to investigate the role of Nrf2 in regulating the mRNA of genes encoding drug metabolizing enzymes and xenobiotic transporters. Microarray analysis was performed in livers of Nrf2-null, wild-type, Keap1-knockdown mice with increased Nrf2 activation, and Keap1-hepatocyte knockout mice with maximum Nrf2 activation. In general, Nrf2 did not have a marked effect on uptake transporters, but the mRNAs of organic anion transporting polypeptide 1a1, sodium taurocholate cotransporting polypeptide, and organic anion transporter 2 were decreased with Nrf2 activation. The effect of Nrf2 on cytochrome P450 (Cyp) genes was minimal, with only Cyp2a5, Cyp2c50, Cyp2c54, and Cyp2g1 increased, and Cyp2u1 decreased with enhanced Nrf2 activation. However, Nrf2 increased mRNA of many other phase-I enzymes, such as aldo-keto reductases, carbonyl reductases, and aldehyde dehydrogenase 1. Many genes involved in phase-II drug metabolism were induced by Nrf2, including glutathione S -transferases, UDP- glucuronosyltransferases, and UDP-glucuronic acid synthesis enzymes. Efflux transporters, such as multidrug resistance-associated proteins, breast cancer resistant protein, as well as ATP-binding cassette g5 and g8 were induced by Nrf2. In conclusion, Nrf2 markedly alters hepatic mRNA of a large number of drug metabolizing enzymes and xenobiotic transporters, and thus Nrf2 plays a central role in xenobiotic metabolism and detoxification. We used microarrays to detail the global programme of gene expression in response to Nrf2 activation and identified distinct classes of up- and down-regulated genes. process.
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Project description:High-throughput phenotype-based screening of large libraries of novel compounds without known targets can identify small molecules that elicit a desired cellular response, but additional approaches are required to find and characterize their targets and mechanisms of action. Here we show that a compound termed lung cancer screen 3 (LCS3), previously selected for its ability to impair the growth of human lung adenocarcinoma (LUAD) cell lines, but not normal lung cells, induces oxidative stress and activates the NRF2 signaling pathway by generating reactive oxygen species (ROS) in sensitive LUAD cell lines. To identify the target that mediates this effect, we applied thermal proteome profiling (TPP) and uncovered the disulfide reductases GSR and TXNRD1 as LCS3 targets. Through enzymatic assays using purified protein, we confirmed that LCS3 inhibits disulfide reductase activity through a reversible, uncompetitive mechanism. Further, we demonstrate that LCS3-sensitive LUAD cells are correspondingly sensitive to the synergistic inhibition of glutathione and thioredoxin pathways. Lastly, a genome-wide CRISPR knockout screen identified the loss of NQO1 as a mechanism of LCS3 resistance. This work highlights the ability of TPP to uncover targets of small molecules identified by high-throughput screens and demonstrates the potential utility of inhibiting disulfide reductases as a therapeutic strategy for LUAD.
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Project description:The nuclear factor erythroid 2-related factor 2 (NRF2) transcription factor activates cytoprotective and metabolic gene expression in response to various electrophilic stressors. In disease, constitutive NRF2 activity promotes cancer progression while decreased NRF2 function contributes to neurodegenerative diseases. In contrast to the regulation of NRF2 protein stability in the cytoplasm, co-complexed proteins that govern NRF2 activity on chromatin are less clear. Using biotin proximity proteomics, we report networks for NRF2 and its family members NRF1, NRF3 and the NRF2 heterodimer MAFG. We found that the Parkinson’s disease zinc finger transcription factor ZNF746 (PARIS) physically associated with NRF2 and MAFG, resulting in suppression of NRF2-driven transcription. ZNF746 expression increased oxidative stress and apoptosis, phenotypes that were reversed by chemical and genetic hyperactivation of NRF2. This study presents a functionally annotated proximity network for NRF2 and suggests that ZNF746 overexpression in Parkinson’s disease directly inhibits NRF2-driven neuroprotection.
2023-12-18 | PXD043248 | Pride
Project description:The nuclear factor erythroid 2-related factor 2 (NRF2) transcription factor activates cytoprotective and metabolic gene expression in response to various electrophilic stressors. In disease, constitutive NRF2 activity promotes cancer progression while decreased NRF2 function contributes to neurodegenerative diseases. In contrast to the regulation of NRF2 protein stability in the cytoplasm, co-complexed proteins that govern NRF2 activity on chromatin are less clear. Using biotin proximity proteomics, we report networks for NRF2 and its family members NRF1, NRF3 and the NRF2 heterodimer MAFG. We found that the Parkinson’s disease zinc finger transcription factor ZNF746 (PARIS) physically associated with NRF2 and MAFG, resulting in suppression of NRF2-driven transcription. ZNF746 expression increased oxidative stress and apoptosis, phenotypes that were reversed by chemical and genetic hyperactivation of NRF2. This study presents a functionally annotated proximity network for NRF2 and suggests that ZNF746 overexpression in Parkinson’s disease directly inhibits NRF2-driven neuroprotection
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Project description:Phenotype-based screening can identify unique small molecules that elicit a desired cellular response, but additional approaches are required to characterize their targets and mechanisms of action. Here we show that a compound termed LCS3, which selectively impairs the growth of human lung adenocarcinoma (LUAD) cells, induces oxidative stress. To identify the target that mediates this effect, we used thermal proteome profiling (TPP) and uncovered the disulfide reductases GSR and TXNRD1 as targets. We confirmed through enzymatic assays that LCS3 inhibits disulfide reductase activity through a reversible, uncompetitive mechanism. Further, we demonstrate that LCS3-sensitive LUAD cells are sensitive to the synergistic inhibition of glutathione and thioredoxin pathways. Lastly, a genome-wide CRISPR knockout screen identified NQO1 loss as a mechanism of LCS3 resistance. This work highlights the ability of TPP to uncover targets of small molecules identified by high-throughput screens and demonstrates the potential therapeutic utility of inhibiting disulfide reductases in LUAD.
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