scholarly journals Sulforaphane-Induced Klf9/Prdx6 Axis Acts as a Molecular Switch to Control Redox Signaling and Determines Fate of Cells

Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1159 ◽  
Author(s):  
Bhavana Chhunchha ◽  
Eri Kubo ◽  
Dhirendra P. Singh
Keyword(s):  
Cell Death ◽  
Antioxidant Defense ◽  
Antioxidant Response ◽  
Therapeutic Interventions ◽  
Related Factor ◽  
Antioxidant Genes ◽  
Peroxiredoxin 6 ◽  
Dose Levels ◽  
Dose Dependent ◽  
Higher Doses

Sulforaphane (SFN), an activator of transcription factor Nrf2 (NFE2-related factor), modulates antioxidant defense by Nrf2-mediated regulation of antioxidant genes like Peroxiredoxin 6 (Prdx6) and affects cellular homeostasis. We previously observed that dose levels of SFN are crucial in determining life or death of lens epithelial cells (LECs). Herein, we demonstrated that higher doses of SFN (>6 μM) activated death signaling by overstimulation of Nrf2/ARE (antioxidant response element)-mediated Kruppel-like factor (Klf9) repression of Prdx6 expression, which increased reactive oxygen species (ROS) load and cell death. Mechanistically, Klf9 bound to its repressive Klf9 binding elements (RKBE; 5-CA/GCCC-3) in the Prdx6 promoter, and repressed Prdx6 transcription. Under the condition of higher dose of SFN, excessive Nrf2 abundance caused death signaling by enforcing Klf9 activation through ARE (5-RTGAYnnnGC-3) in Klf9 promoter that suppress antioxidant genes such as Prdx6 via a Klf9-dependent fashion. Klf9-depletion showed that Klf9 independently caused ROS reduction and subsequent cell survival, demonstrating that Klf9 upregulation caused cell death. Our work revealed the molecular mechanism of dose-dependent altered activity of SFN in LECs, and demonstrated that SFN activity was linked to levels of Nrf2/Klf9/Prdx6 axis. We proposed that in the development of therapeutic interventions for aging/oxidative disorders, combinations of Klf9-ShRNA and Nrf2 inducers may prove to be a promising strategy.

scholarly journals Biological Effect of Different Spinach Extracts in Comparison with the Individual Components of the Phytocomplex

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 382
Author(s):  
Laura Arru ◽  
Francesca Mussi ◽  
Luca Forti ◽  
Annamaria Buschini
Keyword(s):  
Antioxidant Defense ◽  
Extraction Methods ◽  
Oxidizing Agent ◽  
Endogenous Reactive Oxygen Species ◽  
Dependent Activity ◽  
Main Components ◽  
The Individual ◽  
Dose Dependent ◽  
Higher Doses ◽  
Oxidative Insult

The Mediterranean-style diet is rich in fruit and vegetables and has a great impact on the prevention of major chronic diseases, such as cardiovascular diseases and cancer. In this work we investigated the ability of spinach extracts obtained by different extraction methods and of the single main components of the phytocomplex, alone or mixed, to modulate proliferation, antioxidant defense, and genotoxicity of HT29 human colorectal cells. Spinach extracts show dose-dependent activity, increasing the level of intracellular endogenous reactive oxygen species (ROS) when tested at higher doses. In the presence of oxidative stress, the activity is related to the oxidizing agent involved (H2O2 or menadione) and by the extraction method. The single components of the phytocomplex, alone or mixed, do not alter the intracellular endogenous level of ROS but again, in the presence of an oxidative insult, the modulation of antioxidant defense depends on the oxidizing agent used. The application of the phytocomplex extracts seem to be more effective than the application of the single phytocomplex components.

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.

scholarly journals Song Bu Li Decoction, a Traditional Uyghur Medicine, Protects Cell Death by Regulation of Oxidative Stress and Differentiation in Cultured PC12 Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Maitinuer Maiwulanjiang ◽  
Kevin Y. Zhu ◽  
Jianping Chen ◽  
Abudureyimu Miernisha ◽  
Sherry L. Xu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Pc12 Cells ◽  
Stress Proteins ◽  
Antioxidant Response ◽  
Scientific Basis ◽  
Herbal Extract ◽  
Dependent Manner ◽  
Protein Marker ◽  
Dose Dependent

Song Bu Li decoction (SBL) is a traditional Uyghur medicinal herbal preparation, containing Nardostachyos Radix et Rhizoma. Recently, SBL is being used to treat neurological disorders (insomnia and neurasthenia) and heart disorders (arrhythmia and palpitation). Although this herbal extract has been used for many years, there is no scientific basis about its effectiveness. Here, we aimed to evaluate the protective and differentiating activities of SBL in cultured PC12 cells. The pretreatment of SBL protected the cell against tBHP-induced cell death in a dose-dependent manner. In parallel, SBL suppressed intracellular reactive oxygen species (ROS) formation. The transcriptional activity of antioxidant response element (ARE), as well as the key antioxidative stress proteins, was induced in dose-dependent manner by SBL in the cultures. In cultured PC12 cells, the expression of neurofilament, a protein marker for neuronal differentiation, was markedly induced by applied herbal extract. Moreover, the nerve growth factor- (NGF-) induced neurite outgrowth in cultured PC12 cells was significantly potentiated by the cotreatment of SBL. In accord, the expression of neurofilament was increased in the treatment of SBL. These results therefore suggested a possible role of SBL by its effect on neuron differentiation and protection against oxidative stress.

scholarly journals Clock Protein Bmal1 and Nrf2 Cooperatively Control Aging or Oxidative Response and Redox Homeostasis by Regulating Rhythmic Expression of Prdx6

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1861 ◽  
Author(s):  
Bhavana Chhunchha ◽  
Eri Kubo ◽  
Dhirendra P. Singh
Keyword(s):  
Redox Homeostasis ◽  
Antioxidant Response ◽  
Related Factor ◽  
Antioxidant Genes ◽  
Rhythmic Expression ◽  
Circadian Control ◽  
Ros Accumulation ◽  
E Box ◽  
Direct Binding

Many disorders of aging, including blinding-diseases, are associated with deficiency of brain and muscle arnt-like protein 1 (Bmal1) and, thereby, dysregulation of antioxidant-defense pathway. However, knowledge is limited regarding the role of Bmal1 regulation of antioxidant-pathway in the eye lens/lens epithelial cells (LECs) at the molecular level. We found that, in aging human (h)LECs, a progressive decline of nuclear factor erythroid 2-related factor 2 (Nrf2)/ARE (antioxidant response element)-mediated antioxidant genes was connected to Bmal1-deficiency, leading to accumulation of reactive oxygen species (ROS) and cell-death. Bmal1-depletion disrupted Nrf2 and expression of its target antioxidant genes, like Peroxiredoxin 6 (Prdx6). DNA binding and transcription assays showed that Bmal1 controlled expression by direct binding to E-Box in Prdx6 promoter to regulate its transcription. Mutation at E-Box or ARE reduced promoter activity, while disruption of both sites diminished the activity, suggesting that both sites were required for peak Prdx6-transcription. As in aging hLECs, ROS accumulation was increased in Bmal1-deficient cells and the cells were vulnerable to death. Intriguingly, Bmal1/Nrf2/Prdx6 and PhaseII antioxidants showed rhythmic expression in mouse lenses in vivo and were reciprocally linked to ROS levels. We propose that Bmal1 is pivotal for regulating oxidative responses. Findings also reveal a circadian control of antioxidant-pathway, which is important in combating lens/LECs damage induced by aging or oxidative stress.

Abstract P317: Acute Exercise Stress and ROS Signaling: Activation of Nrf2/ARE-Dependent Antioxidant Defense Mechanisms in the Mouse Myocardium

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Corey J Miller ◽  
Kalavathy Ramachandran ◽  
Gayatri D Khanderao ◽  
Sankaranarayanan Kannan ◽  
Vasanthi Rajasekaran ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Acute Exercise ◽  
Nuclear Translocation ◽  
Ischemia Reperfusion ◽  
Antioxidant Response ◽  
Exercise Stress ◽  
Related Factor ◽  
Paramagnetic Resonance ◽  
Antioxidant Genes ◽  
Age Dependent

Background: Cellular defense mechanisms are crucial for maintaining intracellular redox state and mitigating free radical accumulation with aging. Nuclear Erythroid 2 p45 related factor-2 (Nrf2) regulates basal and inducible expression of numerous cytoprotective/antioxidant genes. We hypothesize that acute exercise will induce ROS, which triggers Nrf2/ARE signaling and promotes myocardial defense mechanisms. Methods: Age-matched wild-type (WT) and Nrf2−/− (KO) mice at 2 and >20 months were subjected to acute exercise stress (AES) and then we assessed the activation of Nrf2/ARE-dependent transcriptional mechanisms in the heart. Myocardial ROS was measured by electron paramagnetic resonance (EPR) analysis. Results: Under basal conditions, total ROS and GSH levels were identical at 2 months, whereas they were significantly impaired in Nrf2-KO when compared to Wt myocardium at ∼20 months indicating that Nrf2-deficiency is coupled with blemished redox potential. Upon AES, the young WT and KO mice exhibited oxidative stress (OS), but the WT were able compensate for the stress by increasing Nrf2 nuclear translocation and subsequent upregulation of cytoprotective genes. However, the aged (WT & KO) mice developed OS in response to AES. The degree of OS was several fold higher in the aged Nrf2-KO mice when compared with WT, suggesting an important age dependent function for Nrf2 in the myocardium. Western blot analysis revealed significant down regulation of major antioxidants (GCS, Nqo1, Ho1, catalase, G6pd and Gsr) in KO mice, while WT mice exhibited compensatory antioxidant response to the AES. Gene expression (qPCR) analysis revealed profound upregulation of major antioxidants in WT, but there was no such response occurred in KO mice after AES, suggesting Nrf2 independent mechanisms are inadequate to protect the myocardium. Conclusions: Acute exercise induces ROS and thereby activates Nrf2 in the myocardium. However, disruption of Nrf2 increases susceptibility of the myocardium to OS induced damage. Thus Nrf2 signaling might be a potential therapeutic target to protect the heart from ROS and/or age dependent ischemia/reperfusion (I/R) injury and myocardial infarction (MI).

scholarly journals Glucocorticoid receptor signaling represses the antioxidant response by inhibiting histone acetylation mediated by the transcriptional activator NRF2

2017 ◽  
Vol 292 (18) ◽  
pp. 7519-7530 ◽  
Author(s):  
Md. Morshedul Alam ◽  
Keito Okazaki ◽  
Linh Thi Thao Nguyen ◽  
Nao Ota ◽  
Hiroshi Kitamura ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Glucocorticoid Receptor ◽  
Histone Acetylation ◽  
Transcriptional Activation ◽  
Transcriptional Activator ◽  
Antioxidant Response ◽  
Related Factor ◽  
Dependent Manner ◽  
Antioxidant Genes ◽  
Repressive Effect

NRF2 (nuclear factor erythroid 2-related factor 2) is a key transcriptional activator that mediates the inducible expression of antioxidant genes. NRF2 is normally ubiquitinated by KEAP1 (Kelch-like ECH-associated protein 1) and subsequently degraded by proteasomes. Inactivation of KEAP1 by oxidative stress or electrophilic chemicals allows NRF2 to activate transcription through binding to antioxidant response elements (AREs) and recruiting histone acetyltransferase CBP (CREB-binding protein). Whereas KEAP1-dependent regulation is a major determinant of NRF2 activity, NRF2-mediated transcriptional activation varies from context to context, suggesting that other intracellular signaling cascades may impact NRF2 function. To identify a signaling pathway that modifies NRF2 activity, we immunoprecipitated endogenous NRF2 and its interacting proteins from mouse liver and identified glucocorticoid receptor (GR) as a novel NRF2-binding partner. We found that glucocorticoids, dexamethasone and betamethasone, antagonize diethyl maleate-induced activation of NRF2 target genes in a GR-dependent manner. Dexamethasone treatment enhanced GR recruitment to AREs without affecting chromatin binding of NRF2, resulting in the inhibition of CBP recruitment and histone acetylation at AREs. This repressive effect was canceled by the addition of histone deacetylase inhibitors. Thus, GR signaling decreases NRF2 transcriptional activation through reducing the NRF2-dependent histone acetylation. Consistent with these observations, GR signaling blocked NRF2-mediated cytoprotection from oxidative stress. This study suggests that an impaired antioxidant response by NRF2 and a resulting decrease in cellular antioxidant capacity account for the side effects of glucocorticoids, providing a novel viewpoint for the pathogenesis of hypercorticosteroidism.

scholarly journals The stress response protein REDD1 promotes diabetes-induced oxidative stress in the retina by Keap1-independent Nrf2 degradation

2020 ◽  
Vol 295 (21) ◽  
pp. 7350-7361 ◽  
Author(s):  
William P. Miller ◽  
Siddharth Sunilkumar ◽  
Joseph F. Giordano ◽  
Allyson L. Toro ◽  
Alistair J. Barber ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Glycogen Synthase ◽  
Critical Role ◽  
Antioxidant Response ◽  
Glycogen Synthase Kinase ◽  
Related Factor ◽  
Diabetic Mice ◽  
Antioxidant Genes ◽  
Deficient Mice

The transcription factor nuclear factor erythroid-2–related factor 2 (Nrf2) plays a critical role in reducing oxidative stress by promoting the expression of antioxidant genes. Both individuals with diabetes and preclinical diabetes models exhibit evidence of a defect in retinal Nrf2 activation. We recently demonstrated that increased expression of the stress response protein regulated in development and DNA damage 1 (REDD1) is necessary for the development of oxidative stress in the retina of streptozotocin-induced diabetic mice. In the present study, we tested the hypothesis that REDD1 suppresses the retinal antioxidant response to diabetes by repressing Nrf2 function. We found that REDD1 ablation enhances Nrf2 DNA-binding activity in the retina and that the suppressive effect of diabetes on Nrf2 activity is absent in the retina of REDD1-deficient mice compared with WT. In human MIO-M1 Müller cell cultures, REDD1 deletion prevented oxidative stress in response to hyperglycemic conditions, and this protective effect required Nrf2. REDD1 suppressed Nrf2 stability by promoting its proteasomal degradation independently of Nrf2's interaction with Kelch-like ECH-associated protein 1 (Keap1), but REDD1-mediated Nrf2 degradation required glycogen synthase kinase 3 (GSK3) activity and Ser-351/Ser-356 of Nrf2. Diabetes diminished inhibitory phosphorylation of glycogen synthase kinase 3β (GSK3β) at Ser-9 in the retina of WT mice but not in REDD1-deficient mice. Pharmacological inhibition of GSK3 enhanced Nrf2 activity and prevented oxidative stress in the retina of diabetic mice. The findings support a model wherein hyperglycemia-induced REDD1 blunts the Nrf2 antioxidant response to diabetes by activating GSK3, which, in turn, phosphorylates Nrf2 to promote its degradation.

The Embryotoxic and Immunodepressive Effects of Gossypol

1986 ◽  
Vol 14 (03n04) ◽  
pp. 110-115 ◽  
Author(s):  
G.M. Sein ◽  
M. Phil
Keyword(s):  
Parent Compound ◽  
Lymphocyte Transformation ◽  
Immunological Response ◽  
High Dose ◽  
Intragastric Administration ◽  
Humoral Immune ◽  
Pregnant Mice ◽  
Dose Levels ◽  
Dose Dependent ◽  
Higher Doses

The effects of gossypol acetic on pregnancy, embryofoetal development and on some selected parameters of immunological response in mice were studied. Daily intragastric administration of gossypol (50 or 75 mg/kg/day) during day 1-15 of gestation in mice produced a dose-dependent embroyocidal effect (37.8% and 94.5% respectively) of non-viable foetuses. There was a significant reduction in foetal bodyweight when pregnant mice were treated with gossypol, although no foetal abnormalities were observed. Lymphocyte transformation induced by mitogen concanavalin A, was not inhibited by pretreatment with gossypol (25, 50 or 75 mg/kg/day) for 10 weeks. However, both plaque-forming cells to sheep red blood cell immunisation and the total spleen cell population were significantly depressed by higher doses (50 or 75 mg/kg/day) of gossypol. The results of the present study indicate that gossypol is not teratogenic, but exerts embryocidal and a selective depression humoral immune response at high dose levels (50 or 75 mg/kg/day). It is not clear, whether the dose-dependent embryocidal and/or immunodepressive effects of gossypol are mediated by the parent compound or its metabolites, or whether these findings have any clinical relevance.

scholarly journals Nrf2 is not required for epithelial prohibitin-dependent attenuation of experimental colitis

2013 ◽  
Vol 304 (10) ◽  
pp. G885-G896 ◽  
Author(s):  
Arwa S. Kathiria ◽  
Mackenzie A. Butcher ◽  
Jason M. Hansen ◽  
Arianne L. Theiss
Keyword(s):  
Intestinal Inflammation ◽  
Mitochondrial Protein ◽  
Experimental Colitis ◽  
Antioxidant Response ◽  
Heme Oxygenase 1 ◽  
Trinitrobenzene Sulfonic Acid ◽  
Related Factor ◽  
Intestinal Epithelial ◽  
Quinone Oxidoreductase ◽  
Antioxidant Genes

Inflammatory bowel disease is associated with increased reactive oxygen species (ROS) and decreased antioxidant response in the intestinal mucosa. Expression of the mitochondrial protein prohibitin (PHB) is also decreased during intestinal inflammation. Our previous study showed that genetic restoration of colonic epithelial PHB expression [villin-PHB transgenic (PHB Tg) mice] attenuated dextran sodium sulfate (DSS)-induced colitis/oxidative stress and sustained expression of colonic nuclear factor erythroid 2-related factor 2 (Nrf2), a cytoprotective transcription factor. This study investigated the role of Nrf2 in mediating PHB-induced protection against colitis and expression of the antioxidant response element (ARE)-regulated antioxidant genes heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase-1 (NQO-1). PHB-transfected Caco-2-BBE human intestinal epithelial cells maintained increased ARE activation and decreased intracellular ROS levels compared with control vector-transfected cells during Nrf2 knockdown by small interfering RNA. Treatment with the ERK inhibitor PD-98059 decreased PHB-induced ARE activation, suggesting that ERK constitutes a significant portion of PHB-mediated ARE activation in Caco-2-BBE cells. PHB Tg, Nrf2−/−, and PHB Tg/Nrf2−/− mice were treated with DSS or 2,4,6-trinitrobenzene sulfonic acid (TNBS), and inflammation and expression of HO-1 and NQO-1 were assessed. PHB Tg/Nrf2−/− mice mimicked PHB Tg mice, with attenuated DSS- or TNBS-induced colitis and induction of colonic HO-1 and NQO-1 expression, despite deletion of Nrf2. PHB Tg/Nrf2−/− mice exhibited increased activation of ERK during colitis. Our results suggest that maintaining expression of intestinal epithelial cell PHB, which is decreased during colitis, reduces the severity of inflammation and increases colonic levels of the antioxidants HO-1 and NQO-1 via a mechanism independent of Nrf2.

scholarly journals Nitrosative Redox Homeostasis and Antioxidant Response Defense in Disused Vastus lateralis Muscle in Long-Term Bedrest (Toulouse Cocktail Study)

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 378
Author(s):  
Dieter Blottner ◽  
Daniele Capitanio ◽  
Gabor Trautmann ◽  
Sandra Furlan ◽  
Guido Gambara ◽  
...  
Keyword(s):  
Defense Response ◽  
Antioxidant Defense ◽  
Vastus Lateralis ◽  
Redox Homeostasis ◽  
Antioxidant Response ◽  
Vastus Lateralis Muscle ◽  
Related Factor ◽  
Label Free ◽  
Positive Effects ◽  
Intervention Protocol

Increased oxidative stress by reactive oxygen species (ROS) and reactive nitrogen species (RNS) is a major determinant of disuse-induced muscle atrophy. Muscle biopsies (thigh vastus lateralis, VL) obtained from healthy male subjects enrolled in the Toulouse Cocktail bedrest (BR) study were used to assess efficacy of an antioxidant cocktail (polyphenols, omega-3, vitamin E, and selenium) to counteract the increased redox homeostasis and enhance the antioxidant defense response by using label-free LC–MS/MS and NITRO-DIGE (nitrosated proteins), qPCR, and laser confocal microscopy. Label-free LC–MS/MS indicated that treatment prevented the redox homeostasis dysregulation and promoted structural remodeling (TPM3, MYH7, MYBPC, MYH1, MYL1, HRC, and LUM), increment of RyR1, myogenesis (CSRP3), and skeletal muscle development (MUSTN1, LMNA, AHNAK). These changes were absent in the Placebo group. Glycolysis, tricarboxylic acid cycle (TCA), oxidative phosphorylation, fatty acid beta-oxidation, and mitochondrial transmembrane transport were normalized in treated subjects. Proteins involved in protein folding were also normalized, whereas protein entailed in ion homeostasis decreased. NITRO-DIGE analysis showed significant protein nitrosylation changes for CAT, CA3, SDHA, and VDAC2 in Treatment vs. Placebo. Similarly, the nuclear factor erythroid 2-related factor 2 (Nrf-2) antioxidant response element (Nrf-2 ARE) signaling pathway showed an enhanced response in the Treatment group. Increased nitrosative redox homeostasis and decreased antioxidant defense response were found in post-BR control (Placebo, n = 10) vs. the antioxidant cocktail treated group (Treatment, n = 10). Taken together, increased nitrosative redox homeostasis and muscle deterioration during BR-driven physical inactivity were prevented, whereas decreased antioxidant nitrosative stress defense response was attenuated by Treatment suggesting positive effects of the nutritional intervention protocol in bedrest.

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