scholarly journals Activation of the Nrf2 Pathway by Inorganic Arsenic in Human Hepatocytes and the Role of Transcriptional Repressor Bach1

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Dan Liu ◽  
Xiaoxu Duan ◽  
Dandan Dong ◽  
Caijun Bai ◽  
Xin Li ◽  
...  
Keyword(s):  
Biological Effects ◽  
Transcriptional Repressor ◽  
Inorganic Arsenic ◽  
Cell Types ◽  
Antioxidant Response ◽  
Human Hepatocytes ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Nrf2 Pathway ◽  
Nrf2 Protein

Previous studies have proved that the environmental toxicant, inorganic arsenic, activates nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in many different cell types. This study tried to explore the hepatic Nrf2 pathway upon arsenic treatment comprehensively, since liver is one of the major target organs of arsenical toxicity. Our results showed that inorganic arsenic significantly induced Nrf2 protein and mRNA expression in Chang human hepatocytes. We also observed a dose-dependent increase of antioxidant response element- (ARE-) luciferase activity. Both the mRNA and protein levels of NAD(P)H:quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (HO-1) were all upregulated dramatically. On the other hand, entry and accumulation of Nrf2 protein in the nucleus, while exportting the transcriptional repressor BTB and CNC homology 1 (Bach1) from nucleus to cytoplasm, were also confirmed by western blot and immunofluorescence assay. Our results therefore confirmed the arsenic-induced Nrf2 pathway activation in hepatocytes and also suggested that the translocation of Bach1 was associated with the regulation of Nrf2 pathway by arsenic. Hepatic Nrf2 pathway plays indispensable roles for cellular defenses against arsenic hepatotoxicity, and the interplay of Bach1 and Nrf2 may be helpful to understand the self-defensive responses and the diverse biological effects of arsenicals.

scholarly journals Curcumin Protects Human Keratinocytes against Inorganic Arsenite-Induced Acute Cytotoxicity through an NRF2-Dependent Mechanism

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Rui Zhao ◽  
Bei Yang ◽  
Linlin Wang ◽  
Peng Xue ◽  
Baocheng Deng ◽  
...  
Keyword(s):  
Inorganic Arsenic ◽  
Human Keratinocytes ◽  
Antioxidant Response ◽  
Nuclear Accumulation ◽  
Related Factor ◽  
High Concentration ◽  
Low Concentrations ◽  
Acute Cytotoxicity ◽  
Nrf2 Protein ◽  
Dependent Mechanism

Human exposure to inorganic arsenic leads to various dermal disorders, including hyperkeratosis and skin cancer. Curcumin is demonstrated to induce remarkable antioxidant activity in a variety of cells and tissues. The present study aimed at identifying curcumin as a potent activator of nuclear factor erythroid 2-related factor 2 (NRF2) and demonstrating its protective effect against inorganic arsenite- (iAs3+-) induced cytotoxicity in human keratinocytes. We found that curcumin led to nuclear accumulation of NRF2 protein and increased the expression of antioxidant response element- (ARE-) regulated genes in HaCaT keratinocytes in concentration- and time-dependent manners. High concentration of curcumin (20 μM) also increased protein expression of long isoforms of NRF1. Treatment with low concentrations of curcumin (2.5 or 5 μM) effectively increased the viability and survival of HaCaT cells against iAs3+-induced cytotoxicity as assessed by the MTT assay and flow cytometry and also attenuated iAs3+-induced expression of cleaved caspase-3 and cleaved PARP protein. Selective knockdown ofNRF2orKEAP1by lentiviral shRNAs significantly diminished the cytoprotection conferred by curcumin, suggesting that the protection against iAs3+-induced cytotoxicity is dependent on the activation of NRF2. Our results provided a proof of the concept of using curcumin to activate the NRF2 pathway to alleviate arsenic-induced dermal damage.

scholarly journals Bisphenol A Modulates Autophagy and Exacerbates Chronic Kidney Damage in Mice

2021 ◽  
Vol 22 (13) ◽  
pp. 7189
Author(s):  
Alberto Ruiz Priego ◽  
Emilio González Parra ◽  
Sebastián Mas ◽  
José Luis Morgado-Pascual ◽  
Marta Ruiz-Ortega ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Hepatitis A Virus ◽  
Antioxidant Response ◽  
Heme Oxygenase 1 ◽  
Tubular Damage ◽  
Related Factor ◽  
Related Gene ◽  
Inflammatory Infiltration ◽  
Proximal Tubular Epithelial Cells

BACKGROUND: Bisphenol A (BPA) is a ubiquitous environmental toxin that accumulates in chronic kidney disease (CKD). Our aim was to explore the effect of chronic exposition of BPA in healthy and injured kidney investigating potential mechanisms involved. METHODS: In C57Bl/6 mice, administration of BPA (120 mg/kg/day, i.p for 5 days/week) was done for 2 and 5 weeks. To study BPA effect on CKD, a model of subtotal nephrectomy (SNX) combined with BPA administration for 5 weeks was employed. In vitro studies were done in human proximal tubular epithelial cells (HK-2 line). RESULTS: Chronic BPA administration to healthy mice induces inflammatory infiltration in the kidney, tubular injury and renal fibrosis (assessed by increased collagen deposition). Moreover, in SNX mice BPA exposure exacerbates renal lesions, including overexpression of the tubular damage biomarker Hepatitis A virus cellular receptor 1 (Havcr-1/KIM-1). BPA upregulated several proinflammatory genes and increased the antioxidant response [Nuclear factor erythroid 2-related factor 2 (Nrf2), Heme Oxygenase-1 (Ho-1) and NAD(P)H dehydrogenase quinone 1 (Nqo-1)] both in healthy and SNX mice. The autophagy process was modulated by BPA, through elevated autophagy-related gene 5 (Atg5), autophagy-related gene 7 (Atg7), Microtubule-associated proteins 1A/1B light chain 3B (Map1lc3b/Lc3b) and Beclin-1 gene levels and blockaded the autophagosome maturation and flux (p62 levels). This autophagy deregulation was confirmed in vitro. CONCLUSIONS: BPA deregulates autophagy flux and redox protective mechanisms, suggesting a potential mechanism of BPA deleterious effects in the kidney.

scholarly journals Marine Compound 3-bromo-4,5-dihydroxybenzaldehyde Protects Skin Cells against Oxidative Damage via the Nrf2/HO-1 Pathway

Marine Drugs ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 234 ◽  
Author(s):  
Yea Seong Ryu ◽  
Pincha Devage Sameera Madushan Fernando ◽  
Kyoung Ah Kang ◽  
Mei Jing Piao ◽  
Ao Xuan Zhen ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Antioxidant Response ◽  
Signaling Cascades ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Skin Cells ◽  
Reverse Transcription Pcr ◽  
Extracellular Signal ◽  
Diphenyltetrazolium Bromide ◽  
Marine Compound

In this study, we aimed to illustrate the potential bio-effects of 3-bromo-4,5-dihydroxybenzaldehyde (3-BDB) on the antioxidant/cytoprotective enzyme heme oxygenase-1 (HO-1) in keratinocytes. The antioxidant effects of 3-BDB were examined via reverse transcription PCR, Western blotting, HO-1 activity assay, and immunocytochemistry. Chromatin immunoprecipitation analysis was performed to test for nuclear factor erythroid 2-related factor 2 (Nrf2) binding to the antioxidant response element of the HO-1 promoter. Furthermore, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that the cytoprotective effects of 3-BDB were mediated by the activation of extracellular signal-regulated kinase (ERK) and protein kinase B (PKB, Akt) signaling. Moreover, 3-BDB induced the phosphorylation of ERK and Akt, while inhibitors of ERK and Akt abrogated the 3-BDB-enhanced levels of HO-1 and Nrf2. Finally, 3-BDB protected cells from H2O2- and UVB-induced oxidative damage. This 3-BDB-mediated cytoprotection was suppressed by inhibitors of HO-1, ERK, and Akt. The present results indicate that 3-BDB activated Nrf2 signaling cascades in keratinocytes, which was mediated by ERK and Akt, upregulated HO-1, and induced cytoprotective effects against oxidative stress.

scholarly journals Evidence for a novel antioxidant function and isoform-specific regulation of the human p66Shc gene

2014 ◽  
Vol 25 (13) ◽  
pp. 2116-2127 ◽  
Author(s):  
Masaki Miyazawa ◽  
Yoshiaki Tsuji
Keyword(s):  
Stress Response ◽  
Adaptor Protein ◽  
Erythroid Differentiation ◽  
Cell Types ◽  
Antioxidant Response ◽  
Related Factor ◽  
Antioxidant Genes ◽  
Specific Regulation ◽  
And Function ◽  
Species Production

The mammalian Shc family, composed of p46, p52, and p66 isoforms, serves as an adaptor protein in cell growth and stress response. p66Shc was shown to be a negative lifespan regulator by acting as a prooxidant protein in mitochondria; however, the regulatory mechanisms of p66Shc expression and function are incompletely understood. This study provides evidence for new features of p66Shc serving as an antioxidant and critical protein in cell differentiation. Unique among the Shc family, transcription of p66Shc is activated through the antioxidant response element (ARE)–nuclear factor erythroid 2–related factor 2 (Nrf2) pathway in K562 human erythroleukemia and other cell types after treatment with hemin, an iron-containing porphyrin. Phosphorylated p66Shc at Ser-36, previously reported to be prone to mitochondrial localization, is increased by hemin treatment, but p66Shc remains exclusively in the cytoplasm. p66Shc knockdown inhibits hemin-induced erythroid differentiation, in which reactive oxygen species production and apoptosis are significantly enhanced in conjunction with suppression of other ARE-dependent antioxidant genes. Conversely, p66Shc overexpression is sufficient for inducing erythroid differentiation. Collectively these results demonstrate the isoform-specific regulation of the Shc gene by the Nrf2-ARE pathway and a new antioxidant role of p66Shc in the cytoplasm. Thus p66Shc is a bifunctional protein involved in cellular oxidative stress response and differentiation.

Sodium tanshinone IIA sulfate protects myocardium against paraquat-induced toxicity through activating the Nrf2 signaling pathway in rats

2018 ◽  
Vol 38 (2) ◽  
pp. 247-254 ◽  
Author(s):  
WX Zhang ◽  
XY Xiao ◽  
CG Peng ◽  
WL Chen ◽  
S Xie ◽  
...  
Keyword(s):  
Tanshinone Iia ◽  
Control Group ◽  
Heme Oxygenase 1 ◽  
Intragastric Administration ◽  
Related Factor ◽  
Dependent Manner ◽  
Myocardial Cells ◽  
Sprague Dawley ◽  
Nrf2 Pathway ◽  
Nrf2 Signaling Pathway

Objective: To investigate the therapeutic effect and mechanism of sodium tanshinone IIA sulfate (STS) on paraquat (PQ)-induced myocardial injuries in a rat model. Methods: Healthy adult Sprague Dawley rats were randomly divided into normal control, PQ, and PQ + STS groups. PQ group was given a single intragastric administration of PQ (80 mg/kg). PQ + STS group was intraperitoneally injected with STS (1 ml/kg) at 30 min following PQ exposure. Rats in control and PQ groups were injected with equal amount of saline. After 12, 24, 48, and 72 h, rats were killed, and the apoptosis of myocardial cells was detected. Myocardial expression of Bax and Bcl-2 was measured. The activity of the nuclear erythroid 2-related factor 2 (Nrf2) pathway was assessed by Western blot. Results: The apoptotic cells in PQ group were significantly increased in a time-dependent manner compared with the control group ( p < 0.01). The rats in PQ group exhibited significantly lower Bcl-2 expression, but notably higher Bax expression at 12, 24, 48, and 72 h after PQ exposure ( p < 0.05 or 0.01). STS intervention markedly reduced the proportion of apoptotic myocardial cells, increased Bcl-2 expression, and decreased Bax expression at 24, 48, and 72 h after treatment ( p < 0.05 or 0.01). The expression of phosphorylated Nrf2 and heme oxygenase 1 in PQ + STS group was significantly increased compared with PQ and control groups ( p < 0.05 or 0.01). Conclusion: STS effectively inhibits PQ-induced myocardial cell apoptosis in rats via modulating the Nrf2 pathway, suggesting its potential as a promising therapeutic agent for PQ-induced myocardium damage.

scholarly journals Astragaloside IV Protects Against Oxidative Stress in Calf Small Intestine Epithelial Cells via NFE2L2-Antioxidant Response Element Signaling

2019 ◽  
Vol 20 (24) ◽  
pp. 6131 ◽  
Author(s):  
Yafang Wang ◽  
Fugui Jiang ◽  
Haijian Cheng ◽  
Xiuwen Tan ◽  
Yifan Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Small Intestine ◽  
Epithelial Cells ◽  
Reactive Oxygen Species Generation ◽  
Antioxidant Response ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Antioxidant Response Element ◽  
Astragaloside Iv ◽  
Response Element

Oxidative stress can damage intestinal epithelial cell integrity and function, causing gastrointestinal disorders. Astragaloside IV (ASIV) exhibits a variety of biological and pharmacological properties, including anti-inflammatory and antioxidant effects. The purpose of this research was to investigate the cytoprotective action of ASIV and its mechanisms in calf small intestine epithelial cells with hydrogen peroxide (H2O2)-induced oxidative stress. ASIV pretreatment not only increased cell survival, but it also decreased reactive oxygen species generation and apoptosis, enhanced superoxide dismutase, catalase, and glutathione peroxidase levels, and it reduced malondialdehyde formation. Furthermore, pretreatment with ASIV elevated the mRNA and protein levels of nuclear factor erythroid 2-related factor 2 (NFE2L2), heme oxygenase-1 (HMOX1), and NAD(P)H quinone dehydrogenase 1 (NQO1). The NFE2L2 inhibitor ML385 inhibited NFE2L2 expression and then blocked HMOX1 and NQO1 expression. These results demonstrate that ASIV treatment effectively protects against H2O2-induced oxidative damage in calf small intestine epithelial cells through the activation of the NFE2L2-antioxidant response element signaling pathway.

scholarly journals Allyl Isothiocyanate Protects Acetaminophen-Induced Liver Injury via NRF2 Activation by Decreasing Spontaneous Degradation in Hepatocyte

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3585
Author(s):  
Min Woo Kim ◽  
Ju-Hee Kang ◽  
Hyun Jin Jung ◽  
Se Yong Park ◽  
Thu Han Le Phan ◽  
...  
Keyword(s):  
Target Genes ◽  
Nuclear Translocation ◽  
Biological Effects ◽  
Allyl Isothiocyanate ◽  
Heme Oxygenase 1 ◽  
Toxic Metabolite ◽  
Related Factor ◽  
Dependent Manner ◽  
Nrf2 Activation ◽  
Nrf2 Target Gene

Acetaminophen (APAP) is one of the most frequently prescribed analgesic and anti-pyretic drugs. However, APAP-induced hepatotoxicity is a major cause of acute liver failure globally. While the therapeutic dose is safe, an overdose of APAP produces an excess of the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI), subsequently resulting in hepatotoxicity. Allyl isothiocyanate (AITC), a bioactive molecule in cruciferous plants, is reported to exert various biological effects, including anti-inflammatory, anti-cancer, and anti-microbial effects. Notably, AITC is known for activating nuclear factor erythroid 2-related factor 2 (NRF2), but there is limited evidence supporting the beneficial effects on hepatocytes and liver, where AITC is mainly metabolized. We applied a mouse model in the current study to investigate whether AITC protects the liver against APAP-induced injury, wherein we observed the protective effects of AITC. Furthermore, NRF2 nuclear translocation and the increase of target genes by AITC treatment were confirmed by in vitro experiments. APAP-induced cell damage was attenuated by AITC via an NRF2-dependent manner, and rapid NRF2 activation by AITC was attributed to the elevation of NRF2 stability by decreasing its spontaneous degradation. Moreover, liver tissues from our mouse experiment revealed that AITC increases the expression of heme oxygenase-1 (HO-1), an NRF2 target gene, confirming the potential of AITC as a hepatoprotective agent that induces NRF2 activation. Taken together, our results indicate the potential of AITC as a natural-product-derived NRF2 activator targeting the liver.

scholarly journals LAS0811: From Combinatorial Chemistry to Activation of Antioxidant Response Element

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Ming Zhu ◽  
Hyounggee Baek ◽  
Ruiwu Liu ◽  
Aimin Song ◽  
Kit Lam ◽  
...  
Keyword(s):  
Small Molecules ◽  
Combinatorial Chemistry ◽  
High Throughput Screening ◽  
Cancer Chemoprevention ◽  
Antioxidant Response ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Antioxidant Response Element ◽  
Response Element ◽  
Enhanced Production

The antioxidant response element (ARE) and its transcription factor, nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), are potential targets for cancer chemoprevention. We sought to screen small molecules synthesized with combinatorial chemistry for activation of ARE. By high-throughput screening of 9400 small molecules from 10 combinatorial chemical libraries using HepG2 cells with an ARE-driven reporter, we have identified a novel small molecule, 1,2-dimethoxy-4,5-dinitrobenzene (LAS0811), as an activator of the ARE. LAS0811 upregulated the activity of NAD(P)H:quinone oxidoreductase 1 (NQO1), a representative antioxidative enzyme regulated by ARE. It enhanced production of an endogenous reducing agent, glutathione (GSH). In addition, LAS0811 induced expression of heme oxygenase 1 (HO1), which is an ARE-regulated enzyme with anti-inflammatory activity. Furthermore, LAS0811 reduced cell death due to the cytotoxic stress of a strong oxidant, t-butyl hydroperoxide (t-BOOH). Mechanistically, LAS0811 upregulated the expression of Nrf2 and promoted its translocation into the nuclei leading to subsequent ARE activation. Taken together, LAS0811 is a novel activator of the ARE and its associated detoxifying genes and, thus, a potential agent for cancer chemoprevention.

scholarly journals Bardoxolone methyl (BARD) ameliorates ischemic AKI and increases expression of protective genes Nrf2, PPARγ, and HO-1

2011 ◽  
Vol 300 (5) ◽  
pp. F1180-F1192 ◽  
Author(s):  
Qing Qing Wu ◽  
Yanxia Wang ◽  
Martin Senitko ◽  
Colin Meyer ◽  
W. Christian Wigley ◽  
...  
Keyword(s):  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Therapeutic Benefit ◽  
Heme Oxygenase 1 ◽  
Peroxisome Proliferator ◽  
Related Factor ◽  
Peroxisome Proliferator Activated Receptor ◽  
Peritubular Capillaries ◽  
Protective Genes ◽  
Nrf2 Protein

Ischemic acute kidney injury (AKI) triggers expression of adaptive (protective) and maladaptive genes. Agents that increase expression of protective genes should provide a therapeutic benefit. We now report that bardoxolone methyl (BARD) ameliorates ischemic murine AKI as assessed by both renal function and pathology. BARD may exert its beneficial effect by increasing expression of genes previously shown to protect against ischemic AKI, NF-E2-related factor 2 (Nrf2), peroxisome proliferator-activated receptor-γ (PPARγ), and heme oxygenase 1 (HO-1). Although we found that BARD alone or ischemia-reperfusion alone increased expression of these genes, the greatest increase occurred after the combination of both ischemia-reperfusion and BARD. BARD had a different mode of action than other agents that regulate PPARγ and Nrf2. Thus we report that BARD regulates PPARγ, not by acting as a ligand but by increasing the amount of PPARγ mRNA and protein. This should increase ligand-independent effects of PPARγ. Similarly, BARD increased Nrf2 mRNA; this increased Nrf2 protein by mechanisms in addition to the prolongation of Nrf2 protein half-life previously reported. Finally, we localized expression of these protective genes after ischemia and BARD treatment. Using double-immunofluorescence staining for CD31 and Nrf2 or PPARγ, we found increased Nrf2 and PPARγ on glomerular endothelia in the cortex; Nrf2 was also present on cortical peritubular capillaries. In contrast, HO-1 was localized to different cells, i.e., tubules and interstitial leukocytes. Although Nrf2-dependent increases in HO-1 have been described, our data suggest that BARD's effects on tubular and leukocyte HO-1 during ischemic AKI may be Nrf2 independent. We also found that BARD ameliorated cisplatin nephrotoxicity.

scholarly journals Gain-of-function genetic screen of the kinome reveals BRSK2 as an inhibitor of the NRF2 transcription factor

2020 ◽  
Vol 133 (14) ◽  
pp. jcs241356 ◽  
Author(s):  
Tigist Y. Tamir ◽  
Brittany M. Bowman ◽  
Megan J. Agajanian ◽  
Dennis Goldfarb ◽  
Travis P. Schrank ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Protein Kinase ◽  
Human Cancer ◽  
Antioxidant Response ◽  
Genetic Screen ◽  
Related Factor ◽  
Dependent Manner ◽  
Gain Of Function ◽  
Protein Levels ◽  
Nrf2 Protein

ABSTRACTNuclear factor erythroid 2-related factor 2 (NFE2L2, also known as NRF2) is a transcription factor and master regulator of cellular antioxidant response. Aberrantly high NRF2-dependent transcription is recurrent in human cancer, but conversely NRF2 activity diminishes with age and in neurodegenerative and metabolic disorders. Although NRF2-activating drugs are clinically beneficial, NRF2 inhibitors do not yet exist. Here, we describe use of a gain-of-function genetic screen of the kinome to identify new druggable regulators of NRF2 signaling. We found that the under-studied protein kinase brain-specific kinase 2 (BRSK2) and the related BRSK1 kinases suppress NRF2-dependent transcription and NRF2 protein levels in an activity-dependent manner. Integrated phosphoproteomics and RNAseq studies revealed that BRSK2 drives 5′-AMP-activated protein kinase α2 (AMPK) signaling and suppresses the mTOR pathway. As a result, BRSK2 kinase activation suppresses ribosome-RNA complexes, global protein synthesis and NRF2 protein levels. Collectively, our data illuminate the BRSK2 and BRSK1 kinases, in part by functionally connecting them to NRF2 signaling and mTOR. This signaling axis might prove useful for therapeutically targeting NRF2 in human disease.This article has an associated First Person interview with the first author of the paper.

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