ABSTRACT: investigation of Nrf2 protein complexes and post-translational modification profiles under different methods of stimulation in SKNAS neuroblastoma cells
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.
Project description:We show that NRF2 activation drives hepatocellular carcinoma development in vivo. Moreover, NRF2 undergoes glucose dependent modification called glycation and requires the de-glycating enzyme FN3K to maintain NRF2' oncogenic functions.
Project description:To overcome oxidative, inflammatory, and metabolic stress, cells have evolved networks of cytoprotective proteins controlled by transcription factor nuclear factor erythroid 2 p45-related factor 2 (Nrf2) and its main negative regulator the Kelch-like ECH associated protein 1 (Keap1). Here, we used high-resolution mass-spectrometry to characterize the proteomes of macrophages with altered Nrf2 status. Our analysis revealed significant differences among the genotypes in cellular metabolism and redox homeostasis, which we validated with Seahorse flux and metabolomics, as well as in anti-viral immune pathways, translational regulation and mitosis. Nrf2 disruption significantly affected the proteome following lipopolysaccharide (LPS) stimulation, with alterations in redox, carbohydrate and lipid metabolism, and innate immunity predominantly. Of note, LPS stimulation was found to promote mitochondrial fusion in a process that was dependent on Nrf2. The Keap1 inhibitor, 4-octyl itaconate (4-OI), a derivative of the mitochondrial immunometabolite itaconate, remodeled the inflammatory macrophage proteome, increasing redox and suppressing anti-viral immune effectors in a Nrf2-dependent manner. These data suggest that Nrf2 activation facilitates metabolic reprogramming, mitochondrial adaptation, and finetunes the innate immune response in macrophages.
Project description:Nrf2-regulated mRNAs are known; however, no Nrf2-regulated miRs have been identified miR microarray analysis from total RNA samples was performed to test which miRs are regulated by Nrf2 Total RNA from skin of mice with constitutively active Nrf2 (CMV-caNrf2), dominant-negative Nrf2 (dnNrf2), and correcponding control littermates (K5Cre(wt) for CMV-caNrf2 and wt for dnNrf2)
Project description:Autophagy deficiency caused by conditional knockout of Atg7 results in severe hepatitis accompanied by abundant accumulation of p62. p62 stablizes Nrf2 by disrupting the association between Keap1 and Nrf2. To understand the pathogenesis of hepatitis under the autophagy deficiency, we examined gene expression profiles of livers from Atg7-null, Nrf2-null and Atg7-Nrf2 double mutant mice. Eight week old Atg7F/F:Mx1-Cre mice and Atg7F/F:Mx1-Cre:Nrf2-/- together with control mice were injected with pIpC. At 4 weeks after pIpC injection, total RNAs were purified from each mouse liver.
Project description:Nrf2 (NF-E2-related-factor-2) contributes to the maintenance of glucose homeostasis in vivo. Nrf2 suppresses blood glucose levels by protecting pancreatic β-cells from oxidative stress and improving peripheral tissue glucose utilization. To elucidate the molecular mechanisms by which Nrf2 contributes to the maintenance of glucose homeostasis, we generated skeletal muscle (SkM)-specific Keap1-knockout (Keap1MuKO) mice that express abundant Nrf2 in SkM and then examined Nrf2-target gene expression in this tissue. In Keap1MuKO mice, blood glucose levels were significantly downregulated, and the levels of glycogen branching enzyme (Gbe1) mRNA, along with those of glycogen branching enzyme (GBE) protein, were significantly upregulated in mouse SkM. Consistent with this result, chemical Nrf2-inducers promoted Gbe1 mRNA expression in both mouse SkM and C2C12 myotubes. Chromatin-immunoprecipitation analysis demonstrated that Nrf2 binds the Gbe1 upstream promoter regions. In Keap1MuKO mice, muscle glycogen content was strongly reduced, and forced GBE expression in C2C12 myotubes promoted glucose uptake. Therefore, our results demonstrate that Nrf2-induction in SkM increases GBE expression and reduces muscle glycogen content, resulting in improved glucose tolerance. Chromatin occupancy of Nrf2 under CDDO-Im-treated condition were generated by deep sequencing, in dupliplicate
Project description:The transcription factor Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is activated by the metabolite itaconate during metabolic reprogramming. Activated Nrf2 then dampens the release of pro-inflammatory cytokines and type I IFNs in response to toll-like receptor stimulation. If and how Nrf2 affects cytosolic antiviral sensing and whether this occurs during metabolic reprogramming is currently not known. Here, we show that Nrf2 is a negative regulator of the adaptor molecule STimulator of INterferon Genes (STING), which signals downstream of the cytosolic DNA sensor cyclic GMP-AMP synthase (cGAS). The regulation of STING by Nrf2 was inducible by the metabolite itaconate, specific to human cells, and sufficient to decrease the responsiveness to STING agonists and to increase the susceptibility to infection with DNA viruses. Mechanistically, Nrf2 regulated STING expression post-transcriptionally by increasing STING mRNA stability. Lastly, treatment with itaconate or with the chemical Nrf2 inducer sulforaphane repressed STING expression and the release of type I IFNs in cells from patients with the STING dependent interferonopathy SAVI. With this report we identify Nrf2 as an important regulator of cGAS-STING signaling pathway and link metabolic reprogramming to control of cytosolic DNA sensing.
Project description:To identify Nrf1-dependent and Nrf2-dependent genes in the liver, we examined the gene expression profiles of Nrf1 Alb-CKO, Nrf2 knockout and Keap1 knockdown mouse livers by microarray analyses. Total RNAs from Nrf1dN/-::Alb-Cre, Nrf1dN/+, Nrf2-/-, Nrf2+/+, Keap1KD/- and Keap1KD/+ mouse livers were used for the microarray analyses.
Project description:Cellular oxidative and electrophilic stress triggers a protective response in mammals regulated by NRF2 (nuclear factor (erythroid-derived) 2-like; NFE2L2) binding to DNA-regulatory sequences near stress responsive genes. Studies using Nrf2-deficient mice suggest that hundreds of genes may be regulated by NRF2. To identify human NRF2-regulated genes, we conducted ChIP-sequencing experiments in lymphoid cells treated with the dietary isothiocyanate, sulforaphane (SFN) and carried out follow-up biological experiments on candidates. We found 242 high-confidence, NRF2-bound genomic regions and 96% of these regions contained NRF2-regulatory sequence motifs. The majority of binding sites were near potential novel members of the NRF2 pathway. Validation of selected candidate genes using parallel ChIP techniques and in NRF2-silenced cell lines indicated that the expression of about two thirds of the candidates are likely to be directly NRF2-dependent including retinoid X receptor alpha (RXRA). NRF2 regulation of RXRAhas implications for response to retinoid treatments and adipogenesis. In mouse 3T3-L1 cells SFN treatment affected Rxra expression early in adipogenesis and knockdown of Nrf2 delayed Rxra expression, both leading to impaired adipogenesis. ChIP-Seq analysis of NRF2 binding sites in human lymphoblastoid cells treated with sulforaphane or vehicle