Protein-like Polymers Targeting Keap1/Nrf2 as Therapeutics for Myocardial Infarction
Ontology highlight
ABSTRACT:
ORGANISM(S): Rattus norvegicus
PROVIDER: GSE273545 | GEO | 2025/05/28
REPOSITORIES: GEO
Similar Datasets
Project description:Integrated-systems model of oxidative stress connecting NRF2 and p53 signaling pathways. Additional crosstalk linking oxidative stress to p53 inhibition, p53 to NRF2 through p21, and NRF2 to MDM2 was incorporated in this model. The NRF2 pathway was encoded as first- and second-order rate equations for KEAP1 oxidation and NRF2 stabilization; NRF2-mediated transcription of antioxidant enzymes was modeled as a Hill function. The p53 pathway was reconstructed from a delay differential equation model of p53 signaling in response to DNA damage. To adapt the p53 DNA-damage model to respond to oxidative stress, we used a first-order oxidation reaction of ATM/CHEK2 by intracellular H2O2.
The integrated base model of NRF2–p53 oxidative-stress signaling contains 42 reactions and 22 ordinary differential equations (ODEs).
2021-10-29 | MODEL2110270001 | BioModels
Project description:In the KEAP1-NRF2 stress response system, KEAP1 acts as a sensor for oxidative and electrophilic stresses through formation of S-S bond and C-S bond, respectively. Of the many questions left related to the sensor activity, following three appear important; whether these KEAP1 sensor systems are operating in vivo, whether oxidative and electrophilic stresses are sensed by the similar or distinct systems, and how KEAP1 equips highly sensitive mechanisms detecting oxidative and electrophilic stresses in vivo. To address these questions, we conducted a series of analyses utilizing KEAP1-cysteine substitution mutant mice, conditional selenocysteine-tRNA (Trsp) knockout mice, and human cohort whole genome sequence (WGS) data. The Trsp-knockout provokes severe deficiency of selenoproteins and compensatory activation of NRF2. However, mice lacking homozygously a pair of critical oxidative stress sensor cysteine residues of KEAP1 fail to activate NRF2 in the Trsp-knockout livers. Secondly, this study provides evidence for the differential utilization of KEAP1 sensors for oxidative and electrophilic stresses in vivo. Thirdly, theoretical calculations show that the KEAP1 dimer equips quite sensitive sensor machinery in which modification of a single molecule of KEAP1 within the dimer is sufficient to affect the activity. WGS examinations of rare variants identified seven non-synonymous variants in the oxidative stress sensors in human KEAP1, while no variant was found in electrophilic sensor cysteine residues, supporting the fail-safe nature of the KEAP1 oxidative stress sensor activity. These results provide valuable information for our understanding how mammals respond to oxidative and electrophilic stresses efficiently.
2024-10-09 | GSE276818 | GEO
Project description:Nrf2 (NF-E2-related factor-2) transcription factor regulates oxidative/xenobiotic stress response and also represses inflammation. However, the mechanisms how Nrf2 alleviates inflammation are still unclear. Here, we demonstrate that Nrf2 interferes with lipopolysaccharide-induced transcriptional upregulation of proinflammatory cytokines, including IL-6 and IL-1β. ChIP-seq and ChIP-qPCR analyses revealed that Nrf2 binds to the proximity of these genes in macrophages and inhibits RNA Pol II recruitment. Further, we found that Nrf2-mediated inhibition is independent of the Nrf2 binding motif and reactive oxygen species level. Murine inflammatory models further demonstrated that Nrf2 interferes with IL6 induction and inflammatory phenotypes in vivo. Thus, contrary to the widely accepted view that Nrf2 suppresses inflammation through redox control, we demonstrate here that Nrf2 opposes transcriptional upregulation of proinflammatory cytokine genes. This study identifies Nrf2 as the upstream regulator of cytokine production and establishes a molecular basis for an Nrf2-mediated anti-inflammation approach. Gene expression in BMDMs obtained from wild-type and Keap1-CKO mice. In Keap1-CKO (Keap1 flox/flox::LysM-Cre) BMDMs, Nrf2 transcription factor is activated due to Keap1-deficiency. BMDMs were obtained by a culture of bone marrow cells in the presence of M-CSF for7 days. M1-activated BMDMs were obtained by stimulation with LPS and IFNg for 6 hours, while M2-activated BMDMs were obtained by a stimulation with IL-4 for 6 hours. Two independent BMDM cultures were performed, and each experiment contains samples obtained from one wild-type and one Keap1-CKO mice, respectively.
2016-05-12 | E-GEOD-71263 | biostudies-arrayexpress
Project description:Multiple cancers regulate oxidative stress by activating the transcription factor NRF2 through mutation of its negative regulator KEAP1. NRF2 has been studied extensively in KEAP1-mutant cancers, however the role of this pathway in cancers with wildtype KEAP1 remains poorly understood. To answer this question, we induced NRF2 via pharmacological inactivation of KEAP1 in a panel of 50+ non-small cell lung cancer cell lines. Unexpectedly, marked decreases in viability were observed in >13% of the cell lines—an effect that was rescued by NRF2 ablation. Genome-wide and targeted CRISPR screens revealed that NRF2 induces NADH-reductive stress, through the upregulation of the NAD+-consuming enzyme ALDH3A1. Leveraging these findings, we show that cells treated with KEAP1 inhibitors or those with endogenous KEAP1 mutations are selectively vulnerable to Complex I inhibition, which impairs NADH oxidation capacity and potentiates reductive stress. Thus, we identify reductive stress as a metabolic vulnerability in NRF2-activated lung cancers.
2024-05-24 | PXD039027 | Pride
Project description:The NRF2 transcription factor is constitutively active in cancer where it functions to maintain oxidative homeostasis and reprogram cellular metabolism. NRF2-active tumors exhibit NRF2-dependency and resistance to chemo/radiotherapy. Here we developed VVD-065, a first-in-class NRF2 inhibitor that acts via an unprecedented allosteric molecular glue mechanism. In the absence of stress or mutation, NRF2 is rapidly degraded by the KEAP1-CUL3 ubiquitin-ligase complex. VVD-065 specifically and covalently adducts C151 on KEAP1, which in turn promotes KEAP1-CUL3 complex formation, leading to dramatic enhancement of NRF2 degradation. Previously reported C151-directed compounds decrease KEAP1-CUL3 interactions and stabilize NRF2, thus establishing KEAP1_C151 as a tunable regulator of the KEAP1-CUL3 complex and NRF2 stability. VVD-065 inhibited NRF2-dependent tumor growth and sensitized cancers to chemo/radiotherapy, supporting an open Phase I clinical trial (NCT05954312).
2025-01-03 | GSE278482 | GEO
Project description:Background & Aims: Inflammation in chronic liver diseases induces oxidative stress and thus may contribute to progression of liver injury, fibrosis, and carcinogenesis. The KEAP1/NRF2 axis is a major regulator of cellular redox balance. In the present study, we investigated whether the KEAP1/NRF2 system is involved in liver disease progression in human and mice. Methods: The clinical relevance of oxidative stress was investigated in a well-characterized cohort of NAFLD patients (n=63) by liver RNA sequencing and correlated with histological and clinical parameters. For functional analysis hepatocyte-specific NEMO knock-out (NEMO∆hepa) mice were crossed with hepatocyte-specific KEAP1 knock-out (KEAP1∆hepa) mice. Results: Immunohistochemical analysis of human liver sections showed increased oxidative stress and high NRF2 expression in patients with chronic liver disease. RNA sequencing of liver samples in a human pediatric NAFLD cohort revealed a significant increase of NRF2 activation correlating with the grade of inflammation, but not with the grade of steatosis, which could be confirmed in a second adult NASH cohort. In mice, microarray analysis revealed that KEAP1 deletion induces NRF2 target genes involved in glutathione metabolism and xenobiotic stress (e.g., Nqo1). Furthermore, deficiency of one of the most important antioxidants, glutathione (GSH), in NEMO∆hepa livers was rescued after deleting KEAP1. As a consequence, NEMO∆hepa/KEAP1∆hepa livers showed reduced apoptosis compared to NEMO∆hepa livers as well as a dramatic downregulation of genes involved in cell cycle regulation and DNA replication. Consequently, NEMO∆hepa/KEAP1∆hepa compared to NEMOΔhepa livers displayed decreased fibrogenesis, lower tumor incidence, reduced tumor number, and decreased tumor size. Conclusions: NRF2 activation in NASH patients correlates with the grade of inflammation, but not steatosis. Functional analysis in mice demonstrated that NRF2 activation in chronic liver disease is protective by ameliorating fibrogenesis, initiation and progression of hepatocellular carcinogenesis.
2021-05-26 | GSE156838 | 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.
2014-02-18 | E-GEOD-55001 | biostudies-arrayexpress
Project description:Cancer-derived loss-of-function mutations in the KEAP1 tumor suppressor gene stabilize the NRF2 transcription factor, resulting in a pro-survival gene expression program that alters cellular metabolism and neutralizes oxidative stress. In a previous study of KEAP1 mutations observed in lung cancer, we classified 40% of the mutations as ‘superbinders’ (superbinders). These mutants bind and ubiquitylate NRF2 but do not promote NRF2 degradation. Here, we further investigated the molecular mechanism(s) driving the superbinder phenotype. BioID-based quantitative proteomic analysis of the R320Q and R470C superbinder mutations revealed increased co-complexed NRF2 without significant alteration to other KEAP1-associated proteins, including CUL3, VCP, and several ubiquitin receptors within the proteasome lid. Dynamic simulation modeling and limited proteolysis analyses suggest that superbinder mutations stabilize residues in KEAP1 that contact NRF2. In cells, KEAP1 R320Q and R470C mutants co-localize with NRF2, p62/SQSTM1 and polyubiquitin in spherical clusters that rapidly fuse and dissolve; KEAP1-NRF2 localization to these clusters requires p62. Expression of R320Q and R470C in lung cancer cells provided resistance to the reactive oxygen species-inducing drug bleomycin. We present a model wherein superbinder mutations alter the conformational dynamics of the KEAP1-NRF2 complex to alter the cycling of KEAP1 between open and closed conformations, thus inhibiting NRF2 degradation.
2018-11-07 | PXD008411 | Pride
Project description:The transcription factor NF-E2-related factor 2 (Nrf2) induces cytoprotective genes, but has also been linked to the regulation of hepatic energy metabolism. In order to assess the pharmacological potential of hepatic Nrf2 activation in metabolic disease, Nrf2 was activated over 8 weeks in mice on Western diet using two different siRNAs against kelch-like ECH-associated protein 1 (Keap1), the inhibitory protein of Nrf2. Whole genome expression analysis followed by pathway analysis demonstrated that the suppression of Keap1 expression induced genes that are involved in anti-oxidative stress defense and biotransformation, pathways proving the activation of Nrf2 by the siRNAs against Keap1. The expression of neither fatty acid- nor carbohydrate-handling proteins was regulated by the suppression of Keap1. Metabolic profiling of the animals did also not show effects on plasma and hepatic lipids, energy expenditure or glucose tolerance by the activation of Nrf2. The data indicate that hepatic Nrf2 is not a major regulator of intermediary metabolism in mice. Gene expression profile of mouse liver samples from 8-week-old male C57BL6/J mice (N=24) treated with liver-selective Keap1-specific siRNA (group 1: siKeap1-1, N=8; group 2: siKeap1-2, N=8) or unspecific scrambled control siRNA (group 3: siControl, N=8)
2016-09-01 | E-GEOD-80956 | biostudies-arrayexpress
Project description:The activation of the transcription factor NF-E2-related factor 2 (Nrf2) maintains cellular homeostasis in response to oxidative stress by the regulation of multiple cytoprotective genes. Without stressors the activity of Nrf2 is inhibited by its interaction with the kelch-like ECH-associated protein 1 (Keap1). Here, we describe RA839, a small molecule that binds non-covalently to the Nrf2-interacting kelch domain of Keap1 with a Kd of approximately 6 µM, as demonstrated by X-ray co-crystallization and isothermal titration calorimetry. Whole-genome DNA arrays showed that at 10 µM RA839 significantly regulated 105 genes in bone marrow-derived macrophages. Canonical pathway mapping of these genes revealed an activation of pathways linked with Nrf2 signalling. These pathways were also activated after the activation of Nrf2 by the silencing of Keap1 expression. RA839 regulated only two genes in Nrf2 knockout macrophages. Similar to the activation of Nrf2 by either silencing of Keap1 expression or by the reactive compound CDDO-Me, RA839 prevented the induction of both inducible nitric oxide synthase expression and nitric oxide release in response to lipopolysaccharides in macrophages. In mice RA839 acutely induced Nrf2-target gene expression in liver. RA839 is a selective inhibitor of the Keap1/Nrf2 interaction and a useful tool compound to study the biology of Nrf2. Gene expression profile of bone marrow derived murine macrophages (BMDM) from Nrf2+/+ or Nrf2-/- mice treated with RA838, siKeap1-1 or siKeap1-2 were compared to untreated DMSO control or siControl. Four biological replicates were used for each sample group.
2015-10-31 | E-GEOD-71695 | biostudies-arrayexpress