scholarly journals Hepatocyte-Specific Deficiency of BAP31 Amplified Acetaminophen-Induced Hepatotoxicity via Attenuating Nrf2 Signaling Activation in Mice

2021 ◽  
Vol 22 (19) ◽  
pp. 10788
Author(s):  
Jie Zhao ◽  
Xiaotong Lv ◽  
Yan Huo ◽  
Xiaodi Hu ◽  
Xiaochen Li ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Reductase Activity ◽  
Cell Receptor ◽  
Antioxidant Response ◽  
Related Factor ◽  
Hepatic Inflammation ◽  
Antioxidant Genes ◽  
Jnk Signaling ◽  
Mrna Stabilization ◽  
Signaling Activation

Liver-specific deficiency of B-cell receptor-associated protein 31 knockout mice (BAP31-LKO) and the littermates were injected with acetaminophen (APAP), markers of liver injury, and the potential molecular mechanisms were determined. In response to APAP overdose, serum aspartate aminotransferase and alanine aminotransferase levels were increased in BAP31-LKO mice than in wild-type controls, accompanied by enhanced liver necrosis. APAP-induced apoptosis and mortality were increased. Hepatic glutathione was decreased (1.60 ± 0.31 μmol/g tissue in WT mice vs. 0.85 ± 0.14 μmol/g tissue in BAP31-LKO mice at 6 h, p < 0.05), along with reduced glutathione reductase activity and superoxide dismutase; while malondialdehyde was significantly induced (0.41 ± 0.03 nmol/mg tissue in WT mice vs. 0.50 ± 0.05 nmol/mg tissue in BAP31-LKO mice for 6 h, p < 0.05). JNK signaling activation and APAP-induced hepatic inflammation were increased in BAP31-LKO mice. The mechanism research revealed that BAP31-deficiency decreased Nrf2 mRNA stability (half-life of Nrf2 mRNA decreased from ~1.3 h to ~40 min) and miR-223 expression, led to reduced nuclear factor erythroid 2-related factor 2 (Nrf2) signaling activation and antioxidant genes induction. BAP31-deficiency decreased mitochondrial membrane potentials, reduced mitochondria-related genes expression, and resulted in mitochondrial dysfunction in the liver. Conclusions: BAP31-deficiency reduced the antioxidant response and Nrf2 signaling activation via reducing Nrf2 mRNA stabilization, enhanced JNK signaling activation, hepatic inflammation, and apoptosis, amplified APAP-induced hepatotoxicity in mice.

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 Oregano Essential Oil Induces SOD1 and GSH Expression through Nrf2 Activation and Alleviates Hydrogen Peroxide-Induced Oxidative Damage in IPEC-J2 Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Yi Zou ◽  
Jun Wang ◽  
Jian Peng ◽  
Hongkui Wei
Keyword(s):  
Hydrogen Peroxide ◽  
Essential Oil ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Cell Damage ◽  
Antioxidant Response ◽  
Related Factor ◽  
Protective Effects ◽  
Oregano Essential Oil ◽  
Protein Levels

Oregano essential oil (OEO) has long been used to improve the health of animals, particularly their intestinal health. The health benefits of OEO are generally attributed to antioxidative actions, but the mechanisms remain unclear. Here, we investigate the antioxidative effects of OEO and their underlying molecular mechanisms in porcine small intestinal epithelial (IPEC-J2) cells. We found that OEO treatment prior to hydrogen peroxide (H2O2) exposure increased cell viability and prevented lactate dehydrogenase (LDH) release into the medium. H2O2-induced reactive oxygen species (ROS) and malondialdehyde (MDA) were remarkably suppressed by OEO. OEO dose-dependently increased mRNA and protein levels of the nuclear factor-erythroid 2-related factor-2 (Nrf2) target genes Cu/Zn-superoxide dismutase (SOD1) and g-glutamylcysteine ligase (GCLC, GLCM), as well as intracellular concentrations of SOD1 and glutathione. OEO also increased intranuclear expression of Nrf2 and the activity of an antioxidant response element reporter plasmid in IPEC-J2 cells. The OEO-induced expression of Nrf2-regulated genes and increased SOD1 and glutathione concentrations in IPEC-J2 cells were reduced by Nrf2 small interfering (si) RNAs, counteracting the protective effects of OEO against oxidative stress in IPEC-J2 cells. Our results suggest that OEO protects against H2O2-induced IPEC-J2 cell damage by inducing Nrf2 and related antioxidant enzymes.

scholarly journals Hippo signaling promotes Ets21c-dependent apical cell extrusion in the Drosophila wing disc

2020 ◽  
Author(s):  
Xianlong Ai ◽  
Dan Wang ◽  
Junzheng Zhang ◽  
Jie Shen
Keyword(s):  
Basal Cell ◽  
Molecular Mechanisms ◽  
Apical Cell ◽  
Wing Disc ◽  
Epithelial Tissue ◽  
Hippo Signaling ◽  
Developmental Defects ◽  
Jnk Signaling ◽  
Signaling Activation ◽  
Cell Extrusion

ABSTRACTCell extrusion is a crucial regulator of epithelial tissue development and homeostasis. Epithelial cells undergoing apoptosis, bearing pathological mutations, and possessing developmental defects are actively extruded toward elimination. However, the molecular mechanisms of Drosophila epithelial cell extrusion are not fully understood. Here, we report that activation of the conserved Hippo (Hpo) signaling pathway induces both apical and basal cell extrusion in the Drosophila wing disc epithelia. We show that canonical Yorki targets Diap1, and that dMyc and Cyclin E are not required for either apical or basal cell extrusion induced by activation of this pathway. Another target gene, bantam, is only involved in basal cell extrusion, suggesting novel Hpo-regulated apical cell extrusion mechanisms. Using RNA-Seq analysis, we found that JNK signaling is activated in the extruding cells. We provide genetic evidence that JNK signaling activation is both sufficient and necessary for Hpo-regulated cell extrusion. Furthermore, we demonstrate that the ETS-domain transcription factor Ets21c, an ortholog of proto-oncogenes FLI1 and ERG, acts downstream of JNK signaling to mediate apical cell extrusion. Our findings reveal a novel molecular link between Hpo signaling and cell extrusion.SUMMARY STATEMENTActivation of Hippo signaling induces cell extrusion in the Drosophila wing epithelia, in which bantam mediates basal cell extrusion and Ets21c mediates apical cell extrusion.

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.

Context-Dependent Regulation of Nrf2/ARE Axis on Vascular Cell Function during Hyperglycemic Condition

2020 ◽  
Vol 16 (8) ◽  
pp. 797-806 ◽  
Author(s):  
Tharmarajan Ramprasath ◽  
Allen John Freddy ◽  
Ganesan Velmurugan ◽  
Dhanendra Tomar ◽  
Balakrishnan Rekha ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
High Glucose ◽  
Molecular Mechanisms ◽  
Cell Function ◽  
Vascular Dysfunction ◽  
Redox Balance ◽  
Antioxidant Response ◽  
Antioxidant Genes ◽  
Increased Risk ◽  
Context Dependent

: Diabetes mellitus is associated with an increased risk of micro and macrovascular complications. During hyperglycemic conditions, endothelial cells and vascular smooth muscle cells are exquisitely sensitive to high glucose. This high glucose-induced sustained reactive oxygen species production leads to redox imbalance, which is associated with endothelial dysfunction and vascular wall remodeling. Nrf2, a redox-regulated transcription factor plays a key role in the antioxidant response element (ARE)-mediated expression of antioxidant genes. Although accumulating data indicate the molecular mechanisms underpinning the Nrf2 regulated redox balance, understanding the influence of the Nrf2/ARE axis during hyperglycemic condition on vascular cells is paramount. This review focuses on the context-dependent role of Nrf2/ARE signaling on vascular endothelial and smooth muscle cell function during hyperglycemic conditions. This review also highlights improving the Nrf2 system in vascular tissues, which could be a potential therapeutic strategy for vascular dysfunction.

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 Antioxidant and Anti-Inflammatory Effects of Bischofia javanica (Blume) Leaf Methanol Extracts through the Regulation of Nrf2 and TAK1

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1295
Author(s):  
Sewoong Lee ◽  
Jain Ha ◽  
Jiyoung Park ◽  
Eunjeong Kang ◽  
Sung-Hyun Jeon ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
The Philippines ◽  
No Production ◽  
Related Factor ◽  
Nuclear Factor ◽  
Antioxidant Genes ◽  
Methanol Extracts ◽  
Anti Inflammatory ◽  
Bischofia Javanica

Bischofia javanica (Blume) has been traditionally used to treat inflammatory diseases such as tonsillitis and ulcers throughout Asia, including China, Indonesia, and the Philippines: however, the molecular mechanisms by which B. javanica exerts its antioxidant and anti-inflammatory properties remain largely unknown. In this study, we analyzed the antioxidant and anti-inflammatory mechanisms of methanol extracts of B. javanica leaves (MBJ) in vitro and in vivo. MBJ decreased nitric oxide (NO) production and the expression of pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α, in lipopolysaccharide (LPS)-treated RAW 264.7 cells. The observed suppression of inflammatory responses by MBJ was correlated with an inhibition of the nuclear factor-κB (NF-κB) and the mitogen-activated protein kinase (MAPK) pathways. Additionally, MBJ induced nuclear translocation of the nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that upregulates the expression of anti-inflammatory and antioxidant genes. Furthermore, MBJ exhibited antioxidant and anti-inflammatory effects in an acute hepatitis mouse model. In conclusion, our results confirm the medicinal properties of B. javanica, and therefore MBJ could be applied to improve inflammatory and redox imbalances in different types of pathologies.

scholarly journals Hericium erinaceusInhibits TNF-α-Induced Angiogenesis and ROS Generation through Suppression of MMP-9/NF-κB Signaling and Activation of Nrf2-Mediated Antioxidant Genes in Human EA.hy926 Endothelial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Hebron C. Chang ◽  
Hsin-Ling Yang ◽  
Jih-Hao Pan ◽  
Mallikarjuna Korivi ◽  
Jian-You Pan ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Transcriptional Activation ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Intercellular Adhesion Molecule ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Dependent Manner ◽  
Antioxidant Genes ◽  
Anti Inflammatory

Hericium erinaceus(HE) is an edible mushroom that has been shown to exhibit anticancer and anti-inflammatory activities. We investigated the antiangiogenic and antioxidant potentials of ethanol extracts of HE in human endothelial (EA.hy926) cells upon tumor necrosis factor-α- (TNF-α-) stimulation (10 ng/mL). The underlying molecular mechanisms behind the pharmacological efficacies were elucidated. We found that noncytotoxic concentrations of HE (50–200 μg/mL) significantly inhibited TNF-α-induced migration/invasion and capillary-like tube formation of endothelial cells. HE treatment suppressed TNF-α-induced activity and/or overexpression of matrix metalloproteinase-9 (MMP-9) and intercellular adhesion molecule-1 (ICAM-1). Furthermore, HE downregulated TNF-α-induced nuclear translocation and transcriptional activation of nuclear factor-κB (NF-κB) followed by suppression of I-κB (inhibitor-κB) degradation. Data from fluorescence microscopy illustrated that increased intracellular ROS production upon TNF-α-stimulation was remarkably inhibited by HE pretreatment in a dose-dependent manner. Notably, HE triggered antioxidant gene expressions of heme oxygenase-1 (HO-1),γ-glutamylcysteine synthetase (γ-GCLC), and glutathione levels, which may contribute to inhibition of ROS. Increased antioxidant status was associated with upregulated nuclear translocation and transcriptional activation of NF-E2related factor-2 (Nrf2) in HE treated cells. Our findings conclude that antiangiogenic and anti-inflammatory activities ofH. erinaceusmay contribute to its anticancer property through modulation of MMP-9/NF-κB and Nrf2-antioxidant signaling pathways.

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 Dysregulated Cardiac IGF-1 Signaling and Antioxidant Response Are Associated with Radiation Sensitivity

2020 ◽  
Vol 21 (14) ◽  
pp. 5049 ◽  
Author(s):  
Saeed Y. Aghdam ◽  
Doreswamy Kenchegowda ◽  
Neel K. Sharma ◽  
Gregory P. Holmes-Hampton ◽  
Betre Legesse ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cardiac Tissue ◽  
Antioxidant Response ◽  
Radiation Sensitivity ◽  
Severe Illness ◽  
Related Factor ◽  
Adult Males ◽  
Data Link ◽  
Antioxidant Gene Expression ◽  
Total Body

Acute exposure to ionizing radiation leads to Hematopoietic Acute Radiation Syndrome (H-ARS). To understand the inter-strain cellular and molecular mechanisms of radiation sensitivity, adult males of two strains of minipig, one with higher radiosensitivity, the Gottingen minipig (GMP), and another strain with comparatively lower radiosensitivity, the Sinclair minipig (SMP), were exposed to total body irradiation (TBI). Since Insulin-like Growth Factor-1 (IGF-1) signaling is associated with radiation sensitivity and regulation of cardiovascular homeostasis, we investigated the link between dysregulation of cardiac IGF-1 signaling and radiosensitivity. The adult male GMP; n = 48, and SMP; n = 24, were irradiated using gamma photons at 1.7–2.3 Gy doses. The animals that survived to day 45 after irradiation were euthanized and termed the survivors. Those animals that were euthanized prior to day 45 post-irradiation due to severe illness or health deterioration were termed the decedents. Cardiac tissue analysis of unirradiated and irradiated animals showed that inter-strain radiosensitivity and survival outcomes in H-ARS are associated with activation status of the cardiac IGF-1 signaling and nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated induction of antioxidant gene expression. Our data link H-ARS with dysregulation of cardiac IGF-1 signaling, and highlight the role of oxidative stress and cardiac antioxidant response in radiation sensitivity.

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