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  1. Simvastatin Treatment Upregulates HO-1 in Patients with Abdominal Aortic Aneurysm but Independently of Nrf2

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    Aleksandra Piechota-Polanczyk

    2018-01-01

    Full Text Available Heme oxygenase-1 (HO-1, encoded by HMOX1 gene and regulated by Nrf2 transcription factor, is a cytoprotective enzyme. Its deficiency may exacerbate abdominal aortic aneurysm (AAA development, which is also often associated with hyperlipidemia. Beneficial effects of statins, the broadly used antilipidemic drugs, were attributed to modulation of Nrf2/HO-1 axis. However, the effect of statins on Nrf2/HO-1 pathway in patients with AAA has not been studied yet. We analyzed AAA tissue from patients treated with simvastatin (N = 28 or without statins (N = 14. Simvastatin treatment increased HO-1 protein level in AAA, both in endothelial cells (ECs and in smooth muscle cells (SMCs, but increased Nrf2 localization was restricted only to vasa vasorum. Nrf2 target genes HMOX1, NQO1, and GCLM expression remained unchanged in AAA. In vitro studies showed that simvastatin raises HO-1 protein level slightly in ECs and to much higher extent in SMCs, which is not related to Nrf2/ARE activation, although HMOX1 expression is upregulated by simvastatin in both cell types. In conclusion, simvastatin-induced modulation of HO-1 level in ECs and SMCs in vitro is not related to Nrf2/ARE activity. Likewise, divergent HO-1 and Nrf2 localization together with stable expression of Nrf2 target genes, including HMOX1, in AAA tissue denotes Nrf2 independency.

  2. Embryotoxicity Caused by DON-Induced Oxidative Stress Mediated by Nrf2/HO-1 Pathway

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    Miao Yu

    2017-06-01

    Full Text Available Deoxynivalenol (DON belongs to the type B group of trichothecenes family, which is composed of sesquiterpenoid metabolites produced by Fusarium and other fungi in grain. DON may cause various toxicities, such as cytotoxicity, immunotoxicity, genotoxicity as well as teratogenicity and carcinogenicity. In the present study, we focus on a hypothesis that DON alters the expressions of Nrf2/HO-1 pathway by inducing embryotoxicity in C57BL/6 mouse (5.0, 2.5, 1.0, and 0 mg/kg/day and BeWo cell lines (0 and 50 nM; 3 h, 12 h and 24 h. Our results indicate that DON treatment in mice during pregnancy leads to ROS accumulation in the placenta, which results in embryotoxicity. At the same time Nrf2/HO-1 pathway is up-regulated by ROS to protect placenta cells from oxidative damage. In DON-treated BeWo cells, the level of ROS has time–effect and dose–effect relationships with HO-1 expression. Moderate increase in HO-1 protects the cell from oxidative damage, while excessive increase in HO-1 aggravates the oxidative damage, which is called in some studies the “threshold effect”. Therefore, oxidative stress may be the critical molecular mechanism for DON-induced embryotoxicity. Besides, Nrf2/HO-1 pathway accompanied by the “threshold effect” also plays an important role against DON-induced oxidative damage in this process.

  3. Tetramethylpyrazine improves the recovery of spinal cord injury via Akt/Nrf2/HO-1 pathway.

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    Wang, Chao; Wang, Peng; Zeng, Wen; Li, Weixin

    2016-02-15

    Spinal cord injury (SCI) is one of the most severe traumatic conditions, resulting in postoperative complications. Our results and other reports have shown that tetramethylpyrazine (TMP) is able to exhibit neuro-protective effects after SCI. In the current study, we aimed to examine the possible mechanism underlying the neuro-protective effect of TMP in rat model of SCI. TMP improved locomotor functions and decreased permeability of blood-spinal cord barrier in rats with SCI, as evidenced by increase of Basso-Beattie-Bresnahan scores and decrease of Evans blue leakage. In addition, TMP decreased the expression of several proinflammatory cytokines, including IL-1β, TNFα and IL-18, reduced TUNEL-positive cells and caspase 3 and 9 activities, decreased thiobarbituric acid reactive substances content and increased glutathione level and superoxide dismutase activity in rats. All these effects were inhibited by zinc protoporphyrin IX (ZnPP), an inhibitor of HO-1, and LY294002, an inhibitor of Akt. Moreover, TMP inhibited the decrease of mRNA expression of HO-1 which was suppressed by ZnPP and LY294002. TMP inhibited the decrease of Akt phosphorylation in rats after SCI, which was suppressed by LY294002, but not ZnPP. Furthermore, LY294002, but not ZnPP, significantly inhibited TMP-induced increase of mRNA expression of Nrf2 and DNA binding activity of Nrf2 in HO-1 promoters in rat model of SCI. The data suggested that TMP induced neuro-protective effects against injury of spinal cord through the activation of Akt/Nrf2/HO-1 signaling pathway. These results have appointed a new path toward the understanding of pathogenesis and TMP-related therapy of SCI and associated neurodegenerative diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Finasteride Increases the Expression of Hemoxygenase-1 (HO-1) and NF-E2-Related Factor-2 (Nrf2) Proteins in PC-3 Cells: Implication of Finasteride-Mediated High-Grade Prostate Tumor Occurrence.

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    Yun, Do-Kyung; Lee, June; Keum, Young-Sam

    2013-01-01

    A number of naturally-occurring or synthetic chemicals have been reported to exhibit prostate chemopreventive effects. Synthetic 5α-reductase (5-AR) inhibitors, e.g. finasteride and durasteride, gained special interests as possible prostate chemopreventive agents. Indeed, two large-scale epidemiological studies have demonstrated that finasteride or durasteride significantly reduced the incidence of prostate cancer formation in men. However, these studies have raised an unexpected concern; finasteride and durasteride increased the occurrence of aggressive prostate tumor formation. In the present study, we have observed that treatment of finasteride did not affect the growth of androgen-refractory PC-3 prostate cancer cells. Finasteride also failed to induce apoptosis or affect the expression of proto-oncogenes in PC-3 cells. Interestingly, we found that treatment of finasteride induced the expression of Nrf2 and HO-1 proteins in PC-3 cells. In particular, basal level of Nrf2 protein was higher in androgen-refractory prostate cancer cells, e.g. DU-145 and PC-3 cells, compared with androgen-responsive prostate cancer cells, e.g. LNCaP cells. Also, treatment of finasteride resulted in a selective induction of Nrf2 protein in DU-145 and PC-3 cells, but not in LNCaP cells. In view of the fact that upregulation of Nrf2-mediated phase II cytoprotective enzymes contribute to attenuating tumor promotion in normal cells, but, on the other hand, confers a selective advantage for cancer cells to proliferate and survive against chemical carcinogenesis and other forms of toxicity, we propose that finasteride-mediated induction of Nrf2 protein might be responsible, at least in part, for an increased risk of high-grade prostate tumor formation in men.

  5. NRF2 activation is involved in ozonated human serum upregulation of HO-1 in endothelial cells

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    Pecorelli, Alessandra; Bocci, Velio; Acquaviva, Alessandra; Belmonte, Giuseppe; Gardi, Concetta; Virgili, Fabio; Ciccoli, Lucia; Valacchi, Giuseppe

    2013-01-01

    During the last decade, it has been shown that the activation of NRF2 and the binding to electrophile-responsive element (EpREs), stimulates the expression of a great number of genes responsible for the synthesis of phase I and phase II proteins, including antioxidants enzymes and heme oxygenase-1 (HO-1). This critical cell response occurs in cardiovascular, degenerative and chronic infective diseases aggravated by a chronic oxidative stress. In our previous reports we have shown that ozonated plasma is able to up-regulate HO-1 expression in endothelial cells. In the present work we investigated a candidate mechanism involved in this process. After treatment with increasing doses of ozonated serum (20, 40 and 80 μg/mL O 3 per mL of serum), a clear dose dependent activation of NRF2 and the subsequent induction of HO-1 and NAD(P)H quinone oxidoreductase 1(NQO1) was observed. This effect was also present when cells were treated with serum and hydrogen peroxide (H 2 O 2 ) or serum and 4-hydroxynonenal (4HNE). Moreover, the treatment with ozonated serum was associated with a dose-dependent activation of extracellular-signal-regulated kinases (ERK1/2) and p38 MAP kinases (p38), not directly involved in NRF2 activation. These data, provide a new insight on the mechanism responsible for the induction of HO-1 expression by ozonated serum in the endothelium, and have a practical importance as an expedient approach to the treatment of patients with both effective orthodox drugs and ozonated autohemotherapy, targeted to the restoration of redox homeostasis. - Highlights: ► Endothelial HO1 is upregulated by ozonated plasma ► This activation is induced by NRF2 and it is ERK independent. ► 4HNE and H 2 O 2 are the main molecules involved in this process. ► Ozonated plasma induced a hormetic effect ► Combination of orthodox medicine and ozonated plasma can be a useful treatment

  6. NRF2 activation is involved in ozonated human serum upregulation of HO-1 in endothelial cells

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    Pecorelli, Alessandra [Department of Molecular and Developmental Medicine, University of Siena (Italy); Child Neuropsychiatry Unit, University Hospital, AOUS, Siena (Italy); Bocci, Velio [Department of Physiology, University of Siena (Italy); Acquaviva, Alessandra [Department of Molecular and Developmental Medicine, University of Siena (Italy); Belmonte, Giuseppe [Department of Biomedical Sciences, University of Siena (Italy); Gardi, Concetta [Department of Molecular and Developmental Medicine, University of Siena (Italy); Virgili, Fabio [INRAN, Rome (Italy); Ciccoli, Lucia [Department of Molecular and Developmental Medicine, University of Siena (Italy); Valacchi, Giuseppe, E-mail: giuseppe.valacchi@unife.it [Department of Life Sciences and Biotechnology, University of Ferrara (Italy); Department of Food and Nutrition, Kyung Hee University, Seoul (Korea, Republic of)

    2013-02-15

    During the last decade, it has been shown that the activation of NRF2 and the binding to electrophile-responsive element (EpREs), stimulates the expression of a great number of genes responsible for the synthesis of phase I and phase II proteins, including antioxidants enzymes and heme oxygenase-1 (HO-1). This critical cell response occurs in cardiovascular, degenerative and chronic infective diseases aggravated by a chronic oxidative stress. In our previous reports we have shown that ozonated plasma is able to up-regulate HO-1 expression in endothelial cells. In the present work we investigated a candidate mechanism involved in this process. After treatment with increasing doses of ozonated serum (20, 40 and 80 μg/mL O{sub 3} per mL of serum), a clear dose dependent activation of NRF2 and the subsequent induction of HO-1 and NAD(P)H quinone oxidoreductase 1(NQO1) was observed. This effect was also present when cells were treated with serum and hydrogen peroxide (H{sub 2}O{sub 2}) or serum and 4-hydroxynonenal (4HNE). Moreover, the treatment with ozonated serum was associated with a dose-dependent activation of extracellular-signal-regulated kinases (ERK1/2) and p38 MAP kinases (p38), not directly involved in NRF2 activation. These data, provide a new insight on the mechanism responsible for the induction of HO-1 expression by ozonated serum in the endothelium, and have a practical importance as an expedient approach to the treatment of patients with both effective orthodox drugs and ozonated autohemotherapy, targeted to the restoration of redox homeostasis. - Highlights: ► Endothelial HO1 is upregulated by ozonated plasma ► This activation is induced by NRF2 and it is ERK independent. ► 4HNE and H{sub 2}O{sub 2} are the main molecules involved in this process. ► Ozonated plasma induced a hormetic effect ► Combination of orthodox medicine and ozonated plasma can be a useful treatment.

  7. Sulforaphane Ameliorates Okadaic Acid-Induced Memory Impairment in Rats by Activating the Nrf2/HO-1 Antioxidant Pathway.

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    Dwivedi, Subhash; Rajasekar, N; Hanif, Kashif; Nath, Chandishwar; Shukla, Rakesh

    2016-10-01

    Okadaic acid (OKA) causes memory impairment and attenuates nuclear factor erythroid 2-related factor 2 (Nrf2) along with oxidative stress and neuroinflammation in rats. Sulforaphane (dietary isothiocyanate compound), an activator of Nrf2 signaling, exhibits neuroprotective effects. However, the protective effect of sulforaphane in OKA-induced neurotoxicity remains uninvestigated. Therefore, in the present study, the role of sulforaphane in OKA-induced memory impairment in rats was explored. A significant increased Nrf2 expression in the hippocampus and cerebral cortex was observed in trained (Morris water maze) rats, and a significant decreased Nrf2 expression in memory-impaired (OKA, 200 ng icv) rats indicated its involvement in memory function. Sulforaphane administration (5 and 10 mg/kg, ip, days 1 and 2) ameliorates OKA-induced memory impairment in rats. The treatment also restored Nrf2 and its downstream antioxidant protein expression (GCLC, HO-1) and attenuated oxidative stress (ROS, nitrite, GSH), neuroinflammation (NF-κB, TNF-α, IL-10), and neuronal apoptosis in the cerebral cortex and hippocampus of OKA-treated rats. Further, to determine whether modulation of Nrf2 signaling is responsible for the protective effect of sulforaphane, in vitro, Nrf2 siRNA and its downstream HO-1 inhibition studies were carried out in a rat astrocytoma cell line (C6). The protective effects of sulforaphane were abolished with Nrf2 siRNA and HO-1 inhibition in astrocytes. The results suggest that Nrf2-dependent activation of cellular antioxidant machinery results in sulforaphane-mediated protection against OKA-induced memory impairment in rats. Graphical Abstract ᅟ.

  8. The Nrf2/HO-1 Axis in Cancer Cell Growth and Chemoresistance

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    A. L. Furfaro

    2016-01-01

    Full Text Available The transcription factor, nuclear factor erythroid 2 p45-related factor 2 (Nrf2, acts as a sensor of oxidative or electrophilic stresses and plays a pivotal role in redox homeostasis. Oxidative or electrophilic agents cause a conformational change in the Nrf2 inhibitory protein Keap1 inducing the nuclear translocation of the transcription factor which, through its binding to the antioxidant/electrophilic response element (ARE/EpRE, regulates the expression of antioxidant and detoxifying genes such as heme oxygenase 1 (HO-1. Nrf2 and HO-1 are frequently upregulated in different types of tumours and correlate with tumour progression, aggressiveness, resistance to therapy, and poor prognosis. This review focuses on the Nrf2/HO-1 stress response mechanism as a promising target for anticancer treatment which is able to overcome resistance to therapies.

  9. Soybean-Derived Phytoalexins Improve Cognitive Function through Activation of Nrf2/HO-1 Signaling Pathway

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    Ji Yeon Seo

    2018-01-01

    Full Text Available As soy-derived glyceollins are known to induce antioxidant enzymes in various types of cells and tissues, we hypothesized that the compounds could protect neurons from damage due to reactive oxygen species (ROS. In order to examine the neuroprotective effect of glyceollins, primary cortical neurons collected from mice and mouse hippocampal HT22 cells were challenged with glutamate. Glyceollins attenuated glutamate-induced cytotoxicity in primary cortical neuron isolated from mice carrying wild-type nuclear factor (erythroid-derived 2-like 2 (Nrf2, but the compounds were ineffective in those isolated from Nrf2 knockout mice, suggesting the involvement of the Nrf2 signaling pathway in glyceollin-mediated neuroprotection. Furthermore, the inhibition of heme oxygenase-1 (HO-1, a major downstream enzyme of Nrf2, abolished the suppressive effect of glyceollins against glutamate-induced ROS production and cytotoxicity, confirming that activation of HO-1 by glyceollins is responsible for the neuroprotection. To examine whether glyceollins also improve cognitive ability, mice pretreated with glyceollins were challenged with scopolamine and subjected to behavioral tests. Glyceollins attenuated scopolamine-induced cognitive impairment of mice, but failed to enhance memory in Nrf2 knockout mice, suggesting that the memory-enhancing effect is also mediated by the Nrf2 signaling pathway. Overall, glyceollins showed neuroprotection against glutamate-induced damage, and attenuated scopolamine-induced memory deficits in an Nrf2-dependent manner.

  10. Catalase prevents maternal diabetes-induced perinatal programming via the Nrf2-HO-1 defense system.

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    Chang, Shiao-Ying; Chen, Yun-Wen; Zhao, Xin-Ping; Chenier, Isabelle; Tran, Stella; Sauvé, Alexandre; Ingelfinger, Julie R; Zhang, Shao-Ling

    2012-10-01

    We investigated whether overexpression of catalase (CAT) in renal proximal tubular cells (RPTCs) could prevent the programming of hypertension and kidney disease in the offspring of dams with maternal diabetes. Male offspring of nondiabetic and diabetic dams from two transgenic (Tg) lines (Hoxb7-green fluorescent protein [GFP]-Tg [controls] and Hoxb7/CAT-GFP-Tg, which overexpress CAT in RPTCs) were studied from the prenatal period into adulthood. Nephrogenesis, systolic blood pressure, renal hyperfiltration, kidney injury, and reactive oxygen species (ROS) generation were assessed. Gene expression of transforming growth factor-β1 (TGF-β1), nuclear factor erythroid 2p45-related factor-2 (Nrf2), and heme oxygenase-1 (HO-1) was tested in both in vitro and in vivo studies. Renal dysmorphogenesis was observed in offspring of Hoxb7-GFP-Tg dams with severe maternal diabetes; the affected male offspring displayed higher renal ROS generation and developed hypertension and renal hyperfiltration as well as renal injury with heightened TGF-β1 expression in adulthood. These changes were ameliorated in male offspring of diabetic Hoxb7/CAT-GFP-Tg dams via the Nrf2-HO-1 defense system. CAT promoted Nrf2 nuclear translocation and HO-1 gene expression, seen in both in vitro and in vivo studies. In conclusion, CAT overexpression in the RPTCs ameliorated maternal diabetes-induced perinatal programming, mediated, at least in part, by triggering the Nrf2-HO-1 defense system.

  11. Protective Effect of Decursin Extracted from Angelica gigas in Male Infertility via Nrf2/HO-1 Signaling Pathway

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    Woong Jin Bae

    2016-01-01

    Full Text Available Higher testicular temperature results in altered spermatogenesis due to heat-related oxidative stress. We examined the effects of decursin extracted from Angelica gigas Nakai on antioxidant activity in vitro and in a cryptorchidism-induced infertility rat model. TM3 Leydig cell viability was measured based on oxidative stress according to treatment. Either distilled water or AG 400 mg/kg of A. gigas extract was administered orally for 4 weeks after unilateral cryptorchidism was induced. After 1, 2, and 4 weeks, six rats from the control group and six rats from treatment group were sacrificed. Testicular weight, semen quality, antioxidant activities, nuclear factor erythroid 2-related factor 2 (Nrf2 protein, and mRNA expression of Nrf2-regulated genes were analyzed. Treatment with A. gigas extract (1 protected TM3 cells against oxidative stress in a dose-dependent manner, (2 improved the mean weight of the cryptorchid testis, (3 maintained sperm counts, motility, and spermatogenic cell density, (4 decreased levels of 8-hydroxy-2-deoxyguanosine (8-OHdG and increased levels of superoxide dismutase (SOD, (5 significantly increased Nrf2 and heme oxygenase-1 (HO-1, and (6 significantly decreased apoptosis. This study suggests that decursin extracted from A. gigas is a supplemental agent that can reduce oxidative stress by Nrf2-mediated upregulation of HO-1 in rat experimentally induced unilateral cryptorchidism and may improve cryptorchidism-induced infertility.

  12. Small molecule activators of the Nrf2-HO-1 antioxidant axis modulate heme metabolism and inflammation in BV2 microglia cells.

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    Foresti, Roberta; Bains, Sandip K; Pitchumony, Tamil Selvi; de Castro Brás, Lisandra E; Drago, Filippo; Dubois-Randé, Jean-Luc; Bucolo, Claudio; Motterlini, Roberto

    2013-10-01

    The nuclear factor erythroid derived 2-related factor 2 (Nrf2) and the antioxidant protein heme oxygenase-1 (HO-1) are crucial components of the cellular stress response. These two systems work together to combat oxidative stress and inflammation and are attractive drug targets for counteracting different pathologies, including neuroinflammation. We aimed to identify the most effective Nrf2/HO-1 activators that modulate the inflammatory response in microglia cells. In the present study, we searched the literature and selected 56 compounds reported to activate Nrf2 or HO-1 and analyzed them for HO-1 induction at 6 and 24h and cytotoxicity in BV2 microglial cells in vitro. Approximately 20 compounds up-regulated HO-1 at the concentrations tested (5-20 μM) with carnosol, supercurcumin, cobalt protoporphyrin-IX and dimethyl fumarate exhibiting the best induction/low cytotoxicity profile. Up-regulation of HO-1 by some compounds resulted in increased cellular bilirubin levels but did not augment the expression of proteins involved in heme synthesis (ALAS 1) or biliverdin reductase. Bilirubin production by HO-1 inducers correlated with their potency in inhibiting nitrite production after challenge with interferon-γ (INF-γ) or lipopolysaccharide (LPS). The compounds down-regulated the inflammatory response (TNF-α, PGE2 and nitrite) more strongly in cells challenged with INF-γ than LPS, and silencing HO-1 or Nrf2 with shRNA differentially affected the levels of inflammatory markers. These findings indicate that some small activators of Nrf2/HO-1 are effective modulators of microglia inflammation and highlight the chemical scaffolds that can serve for the synthesis of potent new derivatives to counteract neuroinflammation and neurodegeneration. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Sulforaphane Protects Rodent Retinas against Ischemia-Reperfusion Injury through the Activation of the Nrf2/HO-1 Antioxidant Pathway

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    Liu, Ruixing; Brecha, Nicholas C.; Yu, Albert Cheung Hoi; Pu, Mingliang

    2014-01-01

    Retinal ischemia-reperfusion (I/R) injury induces oxidative stress, leukocyte infiltration, and neuronal cell death. Sulforaphane (SF), which can be obtained in cruciferous vegetables such as broccoli, exerts protective effects in response to oxidative stress in various tissues. These effects can be initiated through nuclear factor E2-related factor 2 (Nrf2)-mediated induction of heme oxygenase-1 (HO-1). This investigation was designed to elucidate the neural protective mechanisms of SF in the retinal I/R rat model. Animals were intraperitoneally (i.p.) injected with SF (12.5 mg/kg) or vehicle (corn oil) once a day for 7 consecutive days. Then, retinal I/R was made by elevating the intraocular pressure (IOP) to 130 mmHg for 1 h. To determine if HO-1 was involved in the Nrf2 antioxidant pathway, rats were subjected to protoporphyrin IX zinc (II) (ZnPP, 30 mg/kg, i.p.) treatments at 24 h before retinal ischemia. The neuroprotective effects of SF were assessed by determining the morphology of the retina, counting the infiltrating inflammatory cells and the surviving retinal ganglion cells (RGCs) and amacrine cells, and measuring apoptosis in the retinal layers. The expression of Nrf2 and HO-1 was studied by immunofluorescence analysis and western blotting. I/R induced a marked increase of ROS generation, caused pronounced inflammation, increased the apoptosis of RGCs and amacrine cells and caused the thinning of the inner retinal layer (IRL), and these effects were diminished or abolished by SF pretreatment. Meanwhile, SF pretreatment significantly elevated the nuclear accumulation of Nrf2 and the level of HO-1 expression in the I/R retinas; however, ZnPP reversed the protective effects of SF on I/R retinas. Together, we offer direct evidence that SF had protective effects on I/R retinas, which could be attributed, at least in part, to the activation of the Nrf2/HO-1 antioxidant pathway. PMID:25470382

  14. Sulforaphane protects rodent retinas against ischemia-reperfusion injury through the activation of the Nrf2/HO-1 antioxidant pathway.

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    Hong Pan

    Full Text Available Retinal ischemia-reperfusion (I/R injury induces oxidative stress, leukocyte infiltration, and neuronal cell death. Sulforaphane (SF, which can be obtained in cruciferous vegetables such as broccoli, exerts protective effects in response to oxidative stress in various tissues. These effects can be initiated through nuclear factor E2-related factor 2 (Nrf2-mediated induction of heme oxygenase-1 (HO-1. This investigation was designed to elucidate the neural protective mechanisms of SF in the retinal I/R rat model. Animals were intraperitoneally (i.p. injected with SF (12.5 mg/kg or vehicle (corn oil once a day for 7 consecutive days. Then, retinal I/R was made by elevating the intraocular pressure (IOP to 130 mmHg for 1 h. To determine if HO-1 was involved in the Nrf2 antioxidant pathway, rats were subjected to protoporphyrin IX zinc (II (ZnPP, 30 mg/kg, i.p. treatments at 24 h before retinal ischemia. The neuroprotective effects of SF were assessed by determining the morphology of the retina, counting the infiltrating inflammatory cells and the surviving retinal ganglion cells (RGCs and amacrine cells, and measuring apoptosis in the retinal layers. The expression of Nrf2 and HO-1 was studied by immunofluorescence analysis and western blotting. I/R induced a marked increase of ROS generation, caused pronounced inflammation, increased the apoptosis of RGCs and amacrine cells and caused the thinning of the inner retinal layer (IRL, and these effects were diminished or abolished by SF pretreatment. Meanwhile, SF pretreatment significantly elevated the nuclear accumulation of Nrf2 and the level of HO-1 expression in the I/R retinas; however, ZnPP reversed the protective effects of SF on I/R retinas. Together, we offer direct evidence that SF had protective effects on I/R retinas, which could be attributed, at least in part, to the activation of the Nrf2/HO-1 antioxidant pathway.

  15. Taurine Protects Mouse Spermatocytes from Ionizing Radiation-Induced Damage Through Activation of Nrf2/HO-1 Signaling

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    Wenjun Yang

    2017-12-01

    Full Text Available Background/Aims: The increasing prevalence of ionizing radiation exposure has inevitably raised public concern over the potential detrimental effects of ionizing radiation on male reproductive system function. The detection of drug candidates to prevent reproductive system from damage caused by ionizing radiation is urgent. We aimed to investigate the protective role of taurine on the injury of mouse spermatocyte-derived cells (GC-2 subjected to ionizing radiation. Methods: mouse spermatocytes (GC-2 cells were exposed to ionizing radiation with or without treatment of Taurine. The effect of ionizing radiation and Taurine treatment on GC-2 cells were evaluated by cell viability assay (CCK8, cell cycle and apoptosis. The relative protein abundance change was determined by Western blotting. The siRNA was used to explore whether Nrf2 signaling was involved in the cytoprotection of Taurine. Results: Taurine significantly inhibited the decrease of cell viability, percentage of apoptotic cells and cell cycle arrest induced by ionizing radiation. Western blot analysis showed that taurine significantly limited the ionizing radiation-induced down-regulation of CyclinB1 and CDK1, and suppressed activation of Fas/FasL system pathway. In addition, taurine treatment significantly increased the expression of Nrf2 and HO-1 in GC-2 cells exposed to ionizing radiation, two components in antioxidant pathway. The above cytoprotection of Taurine was blocked by siNrf2. Conclusion: Our results demonstrate that taurine has the potential to effectively protect GC-2 cells from ionizing radiation- triggered damage via upregulation of Nrf2/HO-1 signaling.

  16. Taurine Protects Mouse Spermatocytes from Ionizing Radiation-Induced Damage Through Activation of Nrf2/HO-1 Signaling.

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    Yang, Wenjun; Huang, Jinfeng; Xiao, Bang; Liu, Yan; Zhu, Yiqing; Wang, Fang; Sun, Shuhan

    2017-01-01

    The increasing prevalence of ionizing radiation exposure has inevitably raised public concern over the potential detrimental effects of ionizing radiation on male reproductive system function. The detection of drug candidates to prevent reproductive system from damage caused by ionizing radiation is urgent. We aimed to investigate the protective role of taurine on the injury of mouse spermatocyte-derived cells (GC-2) subjected to ionizing radiation. mouse spermatocytes (GC-2 cells) were exposed to ionizing radiation with or without treatment of Taurine. The effect of ionizing radiation and Taurine treatment on GC-2 cells were evaluated by cell viability assay (CCK8), cell cycle and apoptosis. The relative protein abundance change was determined by Western blotting. The siRNA was used to explore whether Nrf2 signaling was involved in the cytoprotection of Taurine. Taurine significantly inhibited the decrease of cell viability, percentage of apoptotic cells and cell cycle arrest induced by ionizing radiation. Western blot analysis showed that taurine significantly limited the ionizing radiation-induced down-regulation of CyclinB1 and CDK1, and suppressed activation of Fas/FasL system pathway. In addition, taurine treatment significantly increased the expression of Nrf2 and HO-1 in GC-2 cells exposed to ionizing radiation, two components in antioxidant pathway. The above cytoprotection of Taurine was blocked by siNrf2. Our results demonstrate that taurine has the potential to effectively protect GC-2 cells from ionizing radiation- triggered damage via upregulation of Nrf2/HO-1 signaling. © 2017 The Author(s). Published by S. Karger AG, Basel.

  17. Butein induction of HO-1 by p38 MAPK/Nrf2 pathway in adipocytes attenuates high-fat diet induced adipose hypertrophy in mice.

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    Wang, Zheng; Ka, Sun-O; Lee, Youngyi; Park, Byung-Hyun; Bae, Eun Ju

    2017-03-15

    Adipose tissue inflammation and oxidative stress are key components in the development of obesity and insulin resistance. Heme oxygenase (HO)-1 in adipocytes protects against obesity and adipose dysfunction. In this study, we report the identification of butein, a flavonoid chalcone, as a novel inducer of HO-1 expression in adipocytes in vitro and in vivo. Butein upregulated HO-1 mRNA and protein expression in 3T3-L1 adipocytes, accompanied by Kelch-Like ECH-Associated Protein (Keap) 1 degradation and increase in the nuclear level of nuclear factor erythroid 2-related factor 2 (Nrf2). Butein modulation of Keap1 and Nrf2 as well as HO-1 upregulation was reversed by pretreatment with p38 MAPK inhibitor SB203580, indicating the involvement of p38 MAPK in butein activation of Nrf2 in adipocytes. In addition, HO-1 activation by butein led to the inhibitions of reactive oxygen species and adipocyte differentiation, as evidenced by the fact that butein repression of reactive oxygen species and adipogenesis was reversed by pretreatment with HO-1 inhibitor SnPP. Induction of HO-1 expression by butein was also demonstrated in the adipose tissue of C57BL/6 mice fed a high-fat diet administered along with butein for three weeks, and correlated with the inhibitions of adiposity and adipose tissue inflammation, which were reversed by co-administration of SnPP. Altogether, our results demonstrate that butein activates the p38 MAPK/Nrf2/HO-1 pathway to act as a potent inhibitor of adipose hypertrophy and inflammation in a diet-induced obesity model and thus has potential for suppressing obesity-linked metabolic syndrome. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Two sesquiterpene aminoquinones protect against oxidative injury in HaCaT keratinocytes via activation of AMPKα/ERK-Nrf2/ARE/HO-1 signaling.

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    Liu, Li; Wu, Wei; Li, Jing; Jiao, Wei-Hua; Liu, Li-Yun; Tang, Jie; Liu, Lei; Sun, Fan; Han, Bing-Nan; Lin, Hou-Wen

    2018-04-01

    To investigate the cytoprotective effects of two sesquiterpene aminoquinones isolated from the marine sponge Dysidea fragilis, Dysidaminone H (DA8) and 3'-methylamino-avarone (DA14), we examined their effects against hydrogen peroxide (H 2 O 2 )-induced oxidative injury in human keratinocyte cell line and elucidated the underlying mechanisms. Cell viability was detected using a CCK-8 assay kit. Intracellular reactive oxygen species (ROS) production was measured by fluorescence of 2, 7-Dichlorodi-hydrofluorescein diacetate (DCFH-DA). Messenger RNA and protein expression were measured by real-time quantitative PCR and western blotting analysis. Immunocytochemistry was performed to determine the intracellular location of nuclear factorerythroid 2 p45 related factor 2 (Nrf2). The antioxidant response element (ARE)-luciferase reporter gene assay and RNA interference were used to establish the role of ARE and Nrf2. DA8 and DA14 (DAs) resisted H 2 O 2 induced decline of cell viability by inhibiting the accumulation of ROS. Meanwhile, DAs increased HO-1 expression and ARE activity and induced Nrf2 expression, as well as the accumulation of Nrf2 in the cell nucleus. However, silencing of Nrf2 abolished DAs-induced HO-1 expression and ARE luciferase activation. In addition, DAs induced the phosphorylation of both cyclic AMP-activated protein kinase-α (AMPKα) and extracellular signal-regulated kinase (ERK), while specific inhibitors of AMPKα and ERK abrogated HO1 upregulation and Nrf2 activation. DAs provided cytoprotective effects against H 2 O 2 -induced cytotoxicity by activation of the Nrf2/ARE/HO-1 pathway via phosphorylation of AMPKα and ERK. The findings suggested that DA8 and DA14 might be the candidate therapeutic agents for skin diseases caused by oxidative injury. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  19. Activation of the Nrf2/HO-1 antioxidant pathway contributes to the protective effects of Lycium barbarum polysaccharides in the rodent retina after ischemia-reperfusion-induced damage.

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    Meihua He

    Full Text Available Lycium barbarum polysaccharides (LBP, extracts from the wolfberries, are protective to retina after ischemia-reperfusion (I/R. The antioxidant response element (ARE-mediated antioxidant pathway plays an important role in maintaining the redox status of the retina. Heme oxygenase-1 (HO-1, combined with potent AREs in its promoter, is a highly effective therapeutic target for the protection against neurodegenerative diseases, including I/R-induced retinal damage. The aim of our present study was to investigate whether the protective effect of LBP after I/R damage was mediated via activation of the Nrf2/HO-1-antioxidant pathway in the retina. Retinal I/R was induced by an increase in intraocular pressure to 130 mm Hg for 60 minutes. Prior to the induction of ischemia, rats were orally treated with either vehicle (PBS or LBP (1 mg/kg once a day for 1 week. For specific experiments, zinc protoporphyrin (ZnPP, 20 mg/kg, an HO-1 inhibitor, was intraperitoneally administered at 24 h prior to ischemia. The protective effects of LBP were evaluated by quantifying ganglion cell and amacrine cell survival, and by measuring cell apoptosis in the retinal layers. In addition, HO-1 expression was examined using Western blotting and immunofluorescence analyses. Cytosolic and nuclear Nrf2 was measured using immunofluorescent staining. LBP treatment significantly increased Nrf2 nuclear accumulation and HO-1 expression in the retina after I/R injury. Increased apoptosis and a decrease in the number of viable cells were observed in the ganglion cell layer (GCL and inner nuclear layer (INL in the I/R retina, which were reversed by LBP treatment. The HO-1 inhibitor, ZnPP, diminished the LBP treatment-induced protective effects in the retina after I/R. Taken together, these results suggested that LBP partially exerted its beneficial neuroprotective effects via the activation of Nrf2 and an increase in HO-1 protein expression.

  20. Andrographolide Activates Keap1/Nrf2/ARE/HO-1 Pathway in HT22 Cells and Suppresses Microglial Activation by Aβ42 through Nrf2-Related Inflammatory Response.

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    Seo, Ji Yeon; Pyo, Euisun; An, Jin-Pyo; Kim, Jinwoong; Sung, Sang Hyun; Oh, Won Keun

    2017-01-01

    Therapeutic approach of Alzheimer's disease (AD) has been gradually diversified. We examined the therapeutic and preventive potential of andrographolide, which is a lactone diterpenoid from Andrographis paniculata , and focused on the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-mediated heme oxygenase (HO)-1-inducing effects and the inhibitory activity of amyloid beta (A β ) 42 -induced microglial activation related to Nrf2 and nuclear factor κ B (NF- κ B)-mediated inflammatory responses. Andrographolide induced the expression and translocation of Nrf2 from the cytoplasm to the nucleus, thereby activating antioxidant response element (ARE) gene transcription and HO-1 expression in murine hippocampal HT22 cells. Andrographolide eliminated intracellular A β 42 in BV-2 cells and decreased the production of interleukin (IL)-6, IL-1 β , prostaglandin (PG)E 2 , and nitric oxide (NO) because of artificial phagocytic A β 42 . It decreased pNF- κ B accumulation in the nucleus and the expression of inducible nitric oxide synthase (i-NOS) and cyclooxygenase II (COX-II) in the microglial BV-2 cell line. In summary, andrographolide activates Nrf2-mediated HO-1 expression and inhibits A β 42 -overexpressed microglial BV-2 cell activation. These results suggested that andrographolide might have the potential for further examination of the therapeutics of AD.

  1. Andrographolide Activates Keap1/Nrf2/ARE/HO-1 Pathway in HT22 Cells and Suppresses Microglial Activation by Aβ42 through Nrf2-Related Inflammatory Response

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    Ji Yeon Seo

    2017-01-01

    Full Text Available Therapeutic approach of Alzheimer’s disease (AD has been gradually diversified. We examined the therapeutic and preventive potential of andrographolide, which is a lactone diterpenoid from Andrographis paniculata, and focused on the Kelch-like ECH-associated protein 1 (Keap1/nuclear factor (erythroid-derived 2-like 2 (Nrf2-mediated heme oxygenase (HO-1-inducing effects and the inhibitory activity of amyloid beta (Aβ42-induced microglial activation related to Nrf2 and nuclear factor κB (NF-κB-mediated inflammatory responses. Andrographolide induced the expression and translocation of Nrf2 from the cytoplasm to the nucleus, thereby activating antioxidant response element (ARE gene transcription and HO-1 expression in murine hippocampal HT22 cells. Andrographolide eliminated intracellular Aβ42 in BV-2 cells and decreased the production of interleukin (IL-6, IL-1β, prostaglandin (PGE2, and nitric oxide (NO because of artificial phagocytic Aβ42. It decreased pNF-κB accumulation in the nucleus and the expression of inducible nitric oxide synthase (i-NOS and cyclooxygenase II (COX-II in the microglial BV-2 cell line. In summary, andrographolide activates Nrf2-mediated HO-1 expression and inhibits Aβ42-overexpressed microglial BV-2 cell activation. These results suggested that andrographolide might have the potential for further examination of the therapeutics of AD.

  2. Sulforaphane preconditioning of the Nrf2/HO-1 defense pathway protects the cerebral vasculature against blood-brain barrier disruption and neurological deficits in stroke.

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    Alfieri, Alessio; Srivastava, Salil; Siow, Richard C M; Cash, Diana; Modo, Michel; Duchen, Michael R; Fraser, Paul A; Williams, Steven C R; Mann, Giovanni E

    2013-12-01

    Disruption of the blood-brain barrier (BBB) and cerebral edema are the major pathogenic mechanisms leading to neurological dysfunction and death after ischemic stroke. The brain protects itself against infarction via activation of endogenous antioxidant defense mechanisms, and we here report the first evidence that sulforaphane-mediated preactivation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target heme oxygenase-1 (HO-1) in the cerebral vasculature protects the brain against stroke. To induce ischemic stroke, Sprague-Dawley rats were subjected to 70 min middle cerebral artery occlusion (MCAo) followed by 4, 24, or 72 h reperfusion. Nrf2 and HO-1 protein expression was upregulated in cerebral microvessels of peri-infarct regions after 4-72 h, with HO-1 preferentially associated with perivascular astrocytes rather than the cerebrovascular endothelium. In naïve rats, treatment with sulforaphane increased Nrf2 expression in cerebral microvessels after 24h. Upregulation of Nrf2 by sulforaphane treatment prior to transient MCAo (1h) was associated with increased HO-1 expression in perivascular astrocytes in peri-infarct regions and cerebral endothelium in the infarct core. BBB disruption, lesion progression, as analyzed by MRI, and neurological deficits were reduced by sulforaphane pretreatment. As sulforaphane pretreatment led to a moderate increase in peroxynitrite generation, we suggest that hormetic preconditioning underlies sulforaphane-mediated protection against stroke. In conclusion, we propose that pharmacological or dietary interventions aimed to precondition the brain via activation of the Nrf2 defense pathway in the cerebral microvasculature provide a novel therapeutic approach for preventing BBB breakdown and neurological dysfunction in stroke. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  3. Omega-3 polyunsaturated fatty acid has an anti-oxidant effect via the Nrf-2/HO-1 pathway in 3T3-L1 adipocytes

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    Kusunoki, Chisato; Yang, Liu; Yoshizaki, Takeshi; Nakagawa, Fumiyuki; Ishikado, Atsushi; Kondo, Motoyuki; Morino, Katsutaro; Sekine, Osamu; Ugi, Satoshi; Nishio, Yoshihiko; Kashiwagi, Atsunori; Maegawa, Hiroshi

    2013-01-01

    Highlights: ► Omega-3 PUFA has a direct anti-oxidant effect in adipocytes. ► EPA and DHA induce HO-1 expression in 3T3-L1 adipocytes. ► Omega-3 PUFA and its end-product, 4-HHE, activates the Nrf-2/HO-1 pathway. ► Omega-3 PUFA protects against oxidative stress-induced cytotoxicity. -- Abstract: Oxidative stress is produced in adipose tissue of obese subjects and has been associated with obesity-related disorders. Recent studies have shown that omega-3 polyunsaturated fatty acid (ω3-PUFA) has beneficial effects in preventing atherosclerotic diseases and insulin resistance in adipose tissue. However, the role of ω3-PUFA on adipocytes has not been elucidated. In this study, 3T3-L1 adipocytes were treated with ω3-PUFA and its metabolites, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), or 4-hydroxy hexenal (4-HHE). ω3-PUFA and its metabolites dose-dependently increased mRNA and protein levels of the anti-oxidative enzyme, heme oxygenase-1 (HO-1); whereas no changes in the well-known anti-oxidant molecules, superoxide dismutase, catalase, and glutathione peroxidase, were observed. Knockdown of nuclear factor erythroid 2-related factor 2 (Nrf-2) significantly reduced EPA, DHA or 4-HHE-induced HO-1 mRNA and protein expression. Also, pretreatment with ω3-PUFA prevented H 2 O 2 -induced cytotoxicity in a HO-1 dependent manner. In conclusion, treatment with EPA and DHA induced HO-1 through the activation of Nrf-2 and prevented oxidative stress in 3T3-L1 adipocytes. This anti-oxidant defense may be of high therapeutic value for clinical conditions associated with systemic oxidative stress.

  4. Omega-3 polyunsaturated fatty acid has an anti-oxidant effect via the Nrf-2/HO-1 pathway in 3T3-L1 adipocytes

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    Kusunoki, Chisato, E-mail: yosizaki@belle.shiga-med.ac.jp [Department of Medicine, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga 520-2192 (Japan); Yang, Liu; Yoshizaki, Takeshi; Nakagawa, Fumiyuki; Ishikado, Atsushi; Kondo, Motoyuki; Morino, Katsutaro; Sekine, Osamu; Ugi, Satoshi [Department of Medicine, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga 520-2192 (Japan); Nishio, Yoshihiko [Division of Diabetes, Metabolism and Endocrinology, Department of Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544 (Japan); Kashiwagi, Atsunori; Maegawa, Hiroshi [Department of Medicine, Shiga University of Medical Science, Seta Tsukinowa-Cho, Otsu, Shiga 520-2192 (Japan)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Omega-3 PUFA has a direct anti-oxidant effect in adipocytes. Black-Right-Pointing-Pointer EPA and DHA induce HO-1 expression in 3T3-L1 adipocytes. Black-Right-Pointing-Pointer Omega-3 PUFA and its end-product, 4-HHE, activates the Nrf-2/HO-1 pathway. Black-Right-Pointing-Pointer Omega-3 PUFA protects against oxidative stress-induced cytotoxicity. -- Abstract: Oxidative stress is produced in adipose tissue of obese subjects and has been associated with obesity-related disorders. Recent studies have shown that omega-3 polyunsaturated fatty acid ({omega}3-PUFA) has beneficial effects in preventing atherosclerotic diseases and insulin resistance in adipose tissue. However, the role of {omega}3-PUFA on adipocytes has not been elucidated. In this study, 3T3-L1 adipocytes were treated with {omega}3-PUFA and its metabolites, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), or 4-hydroxy hexenal (4-HHE). {omega}3-PUFA and its metabolites dose-dependently increased mRNA and protein levels of the anti-oxidative enzyme, heme oxygenase-1 (HO-1); whereas no changes in the well-known anti-oxidant molecules, superoxide dismutase, catalase, and glutathione peroxidase, were observed. Knockdown of nuclear factor erythroid 2-related factor 2 (Nrf-2) significantly reduced EPA, DHA or 4-HHE-induced HO-1 mRNA and protein expression. Also, pretreatment with {omega}3-PUFA prevented H{sub 2}O{sub 2}-induced cytotoxicity in a HO-1 dependent manner. In conclusion, treatment with EPA and DHA induced HO-1 through the activation of Nrf-2 and prevented oxidative stress in 3T3-L1 adipocytes. This anti-oxidant defense may be of high therapeutic value for clinical conditions associated with systemic oxidative stress.

  5. Penehyclidine Hydrochloride Pretreatment Ameliorates Rhabdomyolysis-Induced AKI by Activating the Nrf2/HO-1 Pathway and Alleviating [corrected] Endoplasmic Reticulum Stress in Rats. The.

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    Wei Zhao

    Full Text Available Acute kidney injury (AKI is one of the most severe complications of rhabdomyolysis (RM. The underlying mechanisms and potential preventions need to be investigated. Penehyclidine hydrochloride (PHC was reported to ameliorate renal ischemia-reperfusion injury, but the effect of PHC on RM-reduced AKI is unknown. In this study, we established a rat model of RM-induced AKI using an intramuscular glycerol injection in the hind limbs. Rats were pretreated with PHC before the glycerol injection, and the heme oxygenase-1 (HO-1 inhibitor ZnPP was introduced to evaluate the effect of HO-1 on RM-induced AKI. PHC pretreatment ameliorated the pathological renal injury and renal dysfunction, and decreased the renal apoptosis rate in RM-induced AKI. PHC significantly up-regulated HO-1 expression, increased HO-1 enzymatic activity and decreased the accumulation of myoglobin in renal tissues. This effect was partly inhibited by ZnPP. PHC pretreatment also effectively up-regulated nuclear factor erythroid 2-related factor 2 (Nrf2 and down-regulated glucose regulated protein 78 (GRP78 and caspase-12 at both the gene and protein levels. These results suggest that the protective effects of PHC pretreatment on RM-induced AKI occur at least in part through activating the Nrf2/HO-1 pathway and alleviating endoplasmic reticulum stress (ERS in rat renal tissues.

  6. Penehyclidine Hydrochloride Pretreatment Ameliorates Rhabdomyolysis-Induced AKI by Activating the Nrf2/HO-1 Pathway and Allevi-ating Endoplasmic Reticulum Stress in Rats

    Science.gov (United States)

    Zhao, Wei; Huang, XuDong; Zhang, LiXia; Yang, XinJun; Wang, LiHui; Chen, YunShuang; Wang, JingHua; Wu, GuangLi

    2016-01-01

    Acute kidney injury (AKI) is one of the most severe complications of rhabdomyolysis (RM). The underlying mechanisms and potential preventions need to be investigated. Penehyclidine hydrochloride (PHC) was reported to ameliorate renal ischemia-reperfusion injury, but the effect of PHC on RM-reduced AKI is unknown. In this study, we established a rat model of RM-induced AKI using an intramuscular glycerol injection in the hind limbs. Rats were pretreated with PHC before the glycerol injection, and the heme oxygenase-1 (HO-1) inhibitor ZnPP was introduced to evaluate the effect of HO-1 on RM-induced AKI. PHC pretreatment ameliorated the pathological renal injury and renal dysfunction, and decreased the renal apoptosis rate in RM-induced AKI. PHC significantly up-regulated HO-1 expression, increased HO-1 enzymatic activity and decreased the accumulation of myoglobin in renal tissues. This effect was partly inhibited by ZnPP. PHC pretreatment also effectively up-regulated nuclear factor erythroid 2-related factor 2 (Nrf2) and down-regulated glucose regulated protein 78 (GRP78) and caspase-12 at both the gene and protein levels. These results suggest that the protective effects of PHC pretreatment on RM-induced AKI occur at least in part through activating the Nrf2/HO-1 pathway and alleviating endoplasmic reticulum stress (ERS) in rat renal tissues. PMID:26987113

  7. Ginsenoside Rg1 Protects Cardiomyocytes Against Hypoxia/Reoxygenation Injury via Activation of Nrf2/HO-1 Signaling and Inhibition of JNK

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    Qianhui Li

    2017-11-01

    Full Text Available Background/Aims: Excessive reactive oxygen species (ROS disturb the physiology of H9c2 cells, which is regarded as a major cause of H9c2 cardiomyocyte apoptosis. Ginsenoside Rg1 is the main active extract of ginseng, which has important antioxidant properties in various cell models. This project investigated the role of ginsenoside Rg1 in hypoxia/reoxygenation (H/R-induced oxidative stress injury in cultured H9c2 cells to reveal the underlying signaling pathways. Methods: H9c2 cells were pretreated with ginsenoside Rg1 for 12 h before exposure to H/R. In the absence or presence of Nrf2siRNA, HO-1 inhibitor (ZnPP-IX, and inhibitors of the MAPK pathway (SB203580, PD98059, SP600125, H9c2 cells were subjected to H/R with Rg1 treatment. The effects and mechanisms of H/R-induced cardiomyocyte injury were measured. Results: Ginsenoside Rg1 treatment suppressed H/R-induced apoptosis and caspase-3 activation. Ginsenoside Rg1 treatment decreased ROS production and mitochondrial membrane depolarization by elevating the intracellular antioxidant capacity of superoxide dismutase (SOD, glutathione peroxidase (GSH-Px, and reduced glutathione (GSH. Furthermore, ginsenoside Rg1 stimulation appeared to result in nuclear translocation of NF-E2-related factor 2 (Nrf2, along with enhanced expression of the downstream target gene heme oxygenase-1 (HO-1 in a dose-dependent manner. However, ginsenoside Rg1-mediated cardioprotection was abolished by Nrf2-siRNA and HO-1 inhibitor. H/R treatment increased the levels of phosphorylated c-Jun N-terminal kinases (p-JNK, which was dramatically attenuated by ginsenoside Rg1 and SP600125 (a specific JNK inhibitor. Conclusion: These observations indicate that ginsenoside Rg1 activates the Nrf2/HO-1 axis and inhibits the JNK pathway in H9c2 cells to protect against oxidative stress.

  8. Curcumin Attenuates on Carbon Tetrachloride-Induced Acute Liver Injury in Mice via Modulation of the Nrf2/HO-1 and TGF-β1/Smad3 Pathway

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    Xinyan Peng

    2018-01-01

    Full Text Available This study aimed to investigate the protective effect of curcumin against carbon tetrachloride (CCl4-induced acute liver injury in a mouse model, and to explain the underlying mechanism. Curcumin at doses of 50, 100 and 200 mg/kg/day were administered orally once daily for seven days prior to CCl4 exposure. At 24 h, curcumin-attenuated CCl4 induced elevated serum transaminase activities and histopathological damage in the mouse’s liver. Curcumin pre-treatment at 50, 100 and 200 mg/kg significantly ameliorated CCl4-induced oxidative stress, characterized by decreased malondialdehyde (MDA formations, and increased superoxide dismutase (SOD, catalase (CAT activities and glutathione (GSH content, followed by a decrease in caspase-9 and -3 activities. Curcumin pre-treatment significantly decreased CCl4-induced inflammation. Furthermore, curcumin pre-treatment significantly down-regulated the expression of TGF-β1 and Smad3 mRNAs (both p < 0.01, and up-regulated the expression of nuclear-factor erythroid 2-related factor 2 (Nrf2 and HO-1 mRNA (both p < 0.01 in the liver. Inhibition of HO-1 attenuated the protective effect of curcumin on CCl4-induced acute liver injury. Given these outcomes, curcumin could protect against CCl4-induced acute liver injury by inhibiting oxidative stress and inflammation, which may partly involve the activation of Nrf2/HO-1 and inhibition of TGF-β1/Smad3 pathways.

  9. Regulation and novel action of thymidine phosphorylase in non-small cell lung cancer: crosstalk with Nrf2 and HO-1.

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    Magdalena Tertil

    Full Text Available Proangiogenic enzyme thymidine phosphorylase (TP is a promising target for anticancer therapy, yet its action in non-small cell lung carcinoma (NSCLC is not fully understood. To elucidate its role in NSCLC tumor growth, NCI-H292 lung mucoepidermoid carcinoma cells and endothelial cells were engineered to overexpress TP by viral vector transduction. NSCLC cells with altered expression of transcription factor Nrf2 or its target gene heme oxygenase-1 (HO-1 were used to study the regulation of TP and the findings from pre-clinical models were related to gene expression data from clinical NSCLC specimens. Overexpression of Nrf2 or HO-1 resulted in upregulation of TP in NCI-H292 cells, an effect mimicked by treatment with an antioxidant N-acetylcysteine and partially reversed by HO-1 knockdown. Overexpression of TP attenuated cell proliferation and migration in vitro, but simultaneously enhanced angiogenic potential of cancer cells supplemented with thymidine. The latter was also observed for SK-MES-1 squamous cell carcinoma and NCI-H460 large cell carcinoma cells. TP-overexpressing NCI-H292 tumors in vivo exhibited better oxygenation and higher expression of IL-8, IL-1β and IL-6. TP overexpression in endothelial cells augmented their angiogenic properties which was associated with enhanced generation of HO-1 and VEGF. Correlation of TP with the expression of HO-1 and inflammatory cytokines was confirmed in clinical samples of NSCLC. Altogether, the increased expression of IL-1β and IL-6 together with proangiogenic effects of TP-expressing NSCLC on endothelium can contribute to tumor growth, implying TP as a target for antiangiogenesis in NSCLC.

  10. Pinocembrin Suppresses H2O2-Induced Mitochondrial Dysfunction by a Mechanism Dependent on the Nrf2/HO-1 Axis in SH-SY5Y Cells.

    Science.gov (United States)

    de Oliveira, Marcos Roberto; da Costa Ferreira, Gustavo; Brasil, Flávia Bittencourt; Peres, Alessandra

    2018-02-01

    Mitochondria are susceptible to redox impairment, which has been associated with neurodegeneration. These organelles are both a source and target of reactive species. In that context, there is increasing interest in finding natural compounds that modulate mitochondrial function and mitochondria-related signaling in order to prevent or to treat diseases involving mitochondrial impairment. Herein, we investigated whether and how pinocembrin (PB) would prevent mitochondrial dysfunction elicited by the exposure of human neuroblastoma SH-SY5Y cells to hydrogen peroxide (H 2 O 2 ). PB (25 μM) was administrated for 4 h before H 2 O 2 treatment (300 μM for 24 h). PB prevented H 2 O 2 -induced loss of cell viability mitochondrial depolarization in SH-SY5Y cells. PB also attenuated redox impairment in mitochondrial membranes. The production of superoxide anion radical (O 2 -• ) and nitric oxide (NO • ) was alleviated by PB in cells exposed to H 2 O 2 . PB suppressed the H 2 O 2 -induced inhibition of the tricarboxylic acid (TCA) cycle enzymes aconitase, α-ketoglutarate dehydrogenase, and succinate dehydrogenase. Furthermore, PB induced anti-inflammatory effects by abolishing the H 2 O 2 -dependent activation of the nuclear factor-κB (NF-κB) and upregulation of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). The PB-induced antioxidant and anti-inflammatory effects are dependent on the heme oxygenate-1 (HO-1) enzyme and on the activation of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), since HO-1 inhibition (with 0.5 μM ZnPP IX) or Nrf2 silencing (with small interfering RNA (siRNA)) abolished the effects of PB. Overall, PB afforded cytoprotection by the Nrf2/HO-1 axis in H 2 O 2 -treated SH-SY5Y cells.

  11. The Nrf2/HO-1 Pathway Mediates the Antagonist Effect of L-Arginine On Renal Ischemia/Reperfusion Injury in Rats

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    Fei Tong

    2017-08-01

    Full Text Available Background/Aims: Ischemia/reperfusion (I/R is the most common cause of acute renal injury. I/R-induced oxidative stress is involved in the development of acute renal injury, which can be reversed by supplementation with L-arginine, a precursor of nitric oxide (NO. This study was conducted to evaluate alterations in the expression of transcription factors [nuclear factor kappa B (NF-κB, nuclear factor-E2-related factor-2 (Nrf2, and heme oxygenase 1 (HO-1] and heat shock protein 70 (HSP70 in the kidney of I/R-induced injury rats. Methods: Sprague-Dawley (SD rats were subjected to bilateral renal ischemia for 45 min followed by reperfusion for 24 h. Group 1, Sham; group 2, I/R; group 3, L-arginine; and group 4, L-arginine+zinc protoporphyrin (ZnPP. The levels of serum creatinine (Scr, blood urea nitrogen (BUN, serum nitric oxide (NO, histic malondialdehyde (MDA and reactive oxygen species (ROS and superoxide dismutase (SOD activity were determined, and the expression levels of Nrf2, HO-1, NF-κB, and HSP70 were evaluated. Results: The treatment of rats with L-arginine produced a significant reduction in the levels of BUN, Scr, MDA and a significant enhancement in the level of NO and in the activity of SOD compared to renal I/R groups. The expression levels of Nrf2, HO-1, and HSP70 were strongly increased, and the expression of NF-κB and production of ROS were significantly decreased in the L-arginine group compared to that of the I/R group. ZnPP increased renal damage and displayed effects opposite to those of L-arginine. Conclusion: These findings suggested that L-arginine/NO reduces renal dysfunction associated with I/R of the kidney and may act as a trigger to regulate the NF-κB, HSP70 and Nrf2/HO-1 signaling cascades.

  12. Prunella vulgaris Suppresses HG-Induced Vascular Inflammation via Nrf2/HO-1/eNOS Activation

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    Ho Sub Lee

    2012-01-01

    Full Text Available Vascular inflammation is an important factor which can promote diabetic complications. In this study, the inhibitory effects of aqueous extract from Prunella vulgaris (APV on high glucose (HG-induced expression of cell adhesion molecules in human umbilical vein endothelial cells (HUVEC are reported. APV decreased HG-induced expression of intercellular adhesion molecule-1 (ICAM-1, vascular cell adhesion molecule-1 (VCAM-1, and E-selectin. APV also dose-dependently inhibited HG-induced adhesion of HL-60 monocytic cells. APV suppressed p65 NF-κB activation in HG-treated cells. APV significantly inhibited the formation of intracellular reactive oxygen species (ROS. HG-stimulated HUVEC secreted gelatinases, however, APV inhibited it. APV induced Akt phosphorylation as well as activation of heme oxygenase-1 (HO-1, eNOS, and nuclear factor E2-related factor 2 (Nrf2, which may protect vascular inflammation caused by HG. In conclusion, APV exerts anti-inflammatory effect via inhibition of ROS/NF-κB pathway by inducing HO-1 and eNOS expression mediated by Nrf2, thereby suggesting that Prunella vulgaris may be a possible therapeutic approach to the inhibition of diabetic vascular diseases.

  13. 20C, a bibenzyl compound isolated from Gastrodia elata, protects PC12 cells against rotenone-induced apoptosis via activation of the Nrf2/ARE/HO-1 signaling pathway.

    Science.gov (United States)

    Huang, Ju-Yang; Yuan, Yu-He; Yan, Jia-Qing; Wang, Ya-Nan; Chu, Shi-Feng; Zhu, Cheng-Gen; Guo, Qing-Lan; Shi, Jian-Gong; Chen, Nai-Hong

    2016-06-01

    Our preliminary study shows that a bibenzyl compound isolated from Gastrodia elata, 2-[4-hydroxy-3-(4-hydroxybenzyl)benzyl]-4-(4-hydroxybenzyl)phenol (designated 20C), protects PC12 cells against H2O2-induced injury. In this study we investigated whether 20C exerted neuroprotective action in a cell model of Parkinson's disease. A cell model of Parkinson's disease was established in PC12 cells by exposure to rotenone (4 μmol/L) for 48 h. Cell viability and apoptosis were assessed, and intracellular ROS level and the mitochondrial membrane potential (MMP) were detected. The expression of apoptosis-related proteins Bax, Bcl-2, cytochrome c, cleaved caspase-3, and oxidative stress-related proteins Nrf2, HO-1 and NQO1 were examined using Western blotting. The mRNA levels of HO-1 and NQO1 were determined with RT-PCR. The nuclear translocation of Nrf2 was observed with immunofluorescence staining. Treatment with rotenone significantly increased the number of apoptotic cells, accompanied by marked increases in the Bax/Bcl-2 ratio, cytochrome c release and caspase-3 activation. Rotenone also increased ROS accumulation, reduced MMP, and increased the nuclear translocation of Nrf2 as well as the mRNA and protein levels of the Nrf2 downstream target genes HO-1 and NQO1 in PC12 cells. Co-treatment with 20C (0.01-1 μmol/L) dose-dependently attenuated rotenone-induced apoptosis and oxidative stress in PC12 cells. Nrf2 knockdown by siRNA partially reversed the protective effects of 20C in rotenone-treated PC12 cells. The bibenzyl compound 20C protects PC12 cells from rotenone-induced apoptosis, at least in part, via activation of the Nrf2/ARE/HO-1 signaling pathway.

  14. Antioxidant and Antifibrotic Effect of a Herbal Formulation In Vitro and in the Experimental Andropause via Nrf2/HO-1 Signaling Pathway

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    Woong Jin Bae

    2017-01-01

    Full Text Available The Korean herbal formulation Ojayeonjonghwan is used for improving late-onset hypogonadism (LOH symptoms such as erectile dysfunction (ED. A previous research suggested that a modified Ojayeonjonghwan (KH-204 could be used as an alternative to the treatment for ED. The pharmacological effects were examined in different conditions, including in vitro and in vivo. We measured the survival rate of TM3 Leydig cells under the oxidative stress condition. The s.c. injection of leuprorelin was used to induce androgen deprivation. We measured serum testosterone levels, oxidative stress, and apoptosis. The results of the treatment by KH-204 (1 preserved TM3 cells from oxidative stress by improving the expression of nuclear factor erythroid 2-related factor 2 (Nrf2/heme oxygenase-1 (HO-1; (2 lowered the expression of transforming growth factor-beta (TGF-β 1/SMAD; (3 increased the average of serum testosterone in androgen-deprived male rats; (4 kept the activation of spermatogenesis; (5 upgraded the contents of 8-hydroxy-20-deoxyguanosine (8-OHdG and degraded the contents of superoxide dismutase (SOD; and (6 reduced apoptosis. We studied that KH-204 improved testicular dysfunction in LOH. It is likely, at least in part, to degrade oxidative stress through the Nrf2/HO-1 pathway. These findings may offer credible evidences for the use of new alternative therapies to treat LOH.

  15. Ethanol extract of Prunus mume fruit attenuates hydrogen peroxide-induced oxidative stress and apoptosis involving Nrf2/HO-1 activation in C2C12 myoblasts

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    Ji Sook Kang

    Full Text Available ABSTRACT The fruit of the Prunus mume (Siebold Siebold & Zucc., Rosaceae (Korean name: Maesil has long been used as a health food or valuable medicinal material in traditional herb medicine in Southeast Asian countries. In this study, we determined the potential therapeutic efficacy of the ethanol extract of P. mume fruits (EEPM against H2O2-induced oxidative stress and apoptosis in the murine skeletal muscle myoblast cell line C2C12, and sought to understand the associated molecular mechanisms. The results indicated that exposure of C2C12 cells to H2O2 caused a reduction in cell viability by increasing the generation of intracellular reactive oxygen species and by disrupting mitochondrial membrane permeability, leading to DNA damage and apoptosis. However, pretreatment of the cells with EEPM before H2O2 exposure effectively attenuated these changes, suggesting that EEPM prevented H2O2-induced mitochondria-dependent apoptosis. Furthermore, the increased ex-pression and phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2 and up-regulation of heme oxygenase-1 (HO-1, a phase II antioxidant enzyme, were detected in EEPM-treated C2C12 cells. We also found that zinc protoporphyrin IX, an HO-1 inhibitor, attenuated the protective effects of EEPM against H2O2-induced reactive oxygen species accumulation and cytotoxicity. Therefore, these results indicate that the activation of the Nrf2/HO-1 pathway might be involved in the protection of EEPM against H2O2-induced cellular oxidative damage. In conclusion, these results show that EEPM contributes to the prevention of oxidative damage and could be used as a nutritional agent for oxidative stress-related diseases.

  16. Alkaloids from Piper nigrum Exhibit Antiinflammatory Activity via Activating the Nrf2/HO-1 Pathway.

    Science.gov (United States)

    Ngo, Quynh Mai Thi; Tran, Phuong Thao; Tran, Manh Hung; Kim, Jeong Ah; Rho, Seong Soo; Lim, Chi-Hwan; Kim, Jin-Cheol; Woo, Mi Hee; Choi, Jae Sui; Lee, Jeong-Hyung; Min, Byung Sun

    2017-04-01

    In the present study, ten alkaloids, namely chabamide (1), pellitorine (2), retrofractamide A (3), pyrroperine (4), isopiperolein B (5), piperamide C9:1 (8E) (6), 6,7-dehydrobrachyamide B (7), 4,5-dihydropiperine (8), dehydropipernonaline (9), and piperine (10), were isolated from the fruits of Piper nigrum. Among these, chabamide (1), pellitorine (2), retrofractamide A (3), isopiperolein B (5), and 6,7-dehydrobrachyamide B (7) exhibited significant inhibitory activity on lipopolysaccharide-induced nitric oxide (NO) production in RAW264.7 cells, with IC 50 values of 6.8, 14.5, 30.2, 23.7, and 38.5 μM, respectively. Furthermore, compound 1 inhibited lipopolysaccharide-induced NO production in bone marrow-derived macrophages with IC 50 value of 9.5 μM. Consistent with NO inhibition, treatment of RAW264.7 cells with chabamide (1), pellitorine (2), and 6,7-dehydrobrachyamide B (7) suppressed expression of inducible NO synthase and cyclooxygenase-2. Chabamide (1), pellitorine (2), and 6,7-dehydrobrachyamide B (7) induced heme-oxygenase-1 expression at the transcriptional level. In addition, compound 1 induced the nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2) and upregulated the expression of Nrf2 target genes, NAD(P)H:quinone oxidoreductase 1 and γ-glutamyl cysteine synthetase catalytic subunit, in a concentration-dependent manner in RAW264.7 cells. These findings suggest that chabamide (1) from P. nigrum exert antiinflammatory effects via the activation of the Nrf2/heme-oxygenase-1 pathway; hence, it might be a promising candidate for the treatment of inflammatory diseases. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Diallyl trisufide protects against oxygen glucose deprivation -induced apoptosis by scavenging free radicals via the PI3K/Akt -mediated Nrf2/HO-1 signaling pathway in B35 neural cells.

    Science.gov (United States)

    Xu, Xian Hua; Li, Gai Li; Wang, Bing Ang; Qin, Yang; Bai, Shu Rong; Rong, Jian; Deng, Tao; Li, Qiang

    2015-07-21

    Oxidative stress contributes to development of ischemic brain damage. Many antioxidants have been proven effective in ameliorating cerebral ischemia injury by inhibiting oxidative stress. DATS, an organosulfuric component of garlic oil, exhibits antioxidative effects. In present study, we used OGD model to investigate the neuroprotective effects of DATS and the mechanisms related to these effects. B35 neural cells exposed to OGD caused a decrease in cell viability and increases in the percentage of apoptotic cells and the level of intracellular cleaved caspase-3, all of which were markedly attenuated by DATS. Further, DATS treatment significantly increased Nrf2 expression and nuclear translocation, upregulated downstream gene HO-1 and inhibited intracellular ROS and MDA generation, all of which were markedly attenuated in cells transfected with Nrf2-specific siRNA. In addition, inhibition of PI3K/Akt signaling by PI3K-specific siRNA not only decreased the expression level of Nrf2 and HO-1 proteins, but also diminished the antioxidative and neuroprotective effect of DATS. Taken together, these results indicate that DATS protects B35 neural cells against OGD-induced cell injury by inhibiting ROS production via upregulating the PI3K/Akt-mediated Nrf2 pathway, which further activates HO-1. Based on our results, DATS may be a potential candidate for intervention in hypoxic-ischemic brain injuries such as stroke. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Maresin 1 Ameliorates Lung Ischemia/Reperfusion Injury by Suppressing Oxidative Stress via Activation of the Nrf-2-Mediated HO-1 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Quanchao Sun

    2017-01-01

    Full Text Available Lung ischemia/reperfusion (I/R injury occurs in various clinical conditions and heavily damaged lung function. Oxidative stress reaction and antioxidant enzymes play a pivotal role in the etiopathogenesis of lung I/R injury. In the current study, we investigated the impact of Maresin 1 on lung I/R injury and explored the possible mechanism involved in this process. MaR 1 ameliorated I/R-induced lung injury score, wet/dry weight ratio, myeloperoxidase, tumor necrosis factor, bronchoalveolar lavage fluid (BALF leukocyte count, BALF neutrophil ratio, and pulmonary permeability index levels in lung tissue. MaR 1 significantly reduced ROS, methane dicarboxylic aldehyde, and 15-F2t-isoprostane generation and restored antioxidative enzyme (superoxide dismutase, glutathione peroxidase, and catalase activities. Administration of MaR 1 improved the expression of nuclear Nrf-2 and cytosolic HO-1 in I/R-treated lung tissue. Furthermore, we also found that the protective effects of MaR 1 on lung tissue injury and oxidative stress were reversed by HO-1 activity inhibitor, Znpp-IX. Nrf-2 transcription factor inhibitor, brusatol, significantly decreased MaR 1-induced nuclear Nrf-2 and cytosolic HO-1 expression. In conclusion, these results indicate that MaR 1 protects against lung I/R injury through suppressing oxidative stress. The mechanism is partially explained by activation of the Nrf-2-mediated HO-1 signaling pathway.

  19. Maresin 1 Ameliorates Lung Ischemia/Reperfusion Injury by Suppressing Oxidative Stress via Activation of the Nrf-2-Mediated HO-1 Signaling Pathway

    Science.gov (United States)

    Wu, You; Zhao, Feng

    2017-01-01

    Lung ischemia/reperfusion (I/R) injury occurs in various clinical conditions and heavily damaged lung function. Oxidative stress reaction and antioxidant enzymes play a pivotal role in the etiopathogenesis of lung I/R injury. In the current study, we investigated the impact of Maresin 1 on lung I/R injury and explored the possible mechanism involved in this process. MaR 1 ameliorated I/R-induced lung injury score, wet/dry weight ratio, myeloperoxidase, tumor necrosis factor, bronchoalveolar lavage fluid (BALF) leukocyte count, BALF neutrophil ratio, and pulmonary permeability index levels in lung tissue. MaR 1 significantly reduced ROS, methane dicarboxylic aldehyde, and 15-F2t-isoprostane generation and restored antioxidative enzyme (superoxide dismutase, glutathione peroxidase, and catalase) activities. Administration of MaR 1 improved the expression of nuclear Nrf-2 and cytosolic HO-1 in I/R-treated lung tissue. Furthermore, we also found that the protective effects of MaR 1 on lung tissue injury and oxidative stress were reversed by HO-1 activity inhibitor, Znpp-IX. Nrf-2 transcription factor inhibitor, brusatol, significantly decreased MaR 1-induced nuclear Nrf-2 and cytosolic HO-1 expression. In conclusion, these results indicate that MaR 1 protects against lung I/R injury through suppressing oxidative stress. The mechanism is partially explained by activation of the Nrf-2-mediated HO-1 signaling pathway. PMID:28751936

  20. Andrographolide protects liver cells from H2O2 induced cell death by upregulation of Nrf-2/HO-1 mediated via adenosine A2a receptor signalling.

    Science.gov (United States)

    Mittal, Smriti P K; Khole, Swati; Jagadish, Nidhi; Ghosh, Debjani; Gadgil, Vijay; Sinkar, Vilas; Ghaskadbi, Saroj S

    2016-11-01

    Andrographolide, principle constituent of Andrographis paniculata Nees is used in traditional medicine in Southeast Asia and is known to exhibit various biological activities. Its antioxidant activity is due to its ability to activate one of the antioxidant enzymes, heme oxygenase-1 (HO-1) which is regulated transcriptionally through Nrf-2. However, molecular mechanism underlying activation of Nrf-2/HO-1 has not yet been clearly understood. Protective effect of andrographolide against H2O2 induced cell death, reactive oxygen species and lipid peroxidation was observed in HepG2 cells. Ability of andrographolide to modulate G-protein coupled receptor (GPCR) mediated signalling was determined using in silico docking and gene expression was analyzed by qRT-PCR, confocal microscopy and western blot analysis. We clearly show that andrographolide via adenosine A2A receptor signalling leads to activation of p38 MAP kinase, resulting in upregulation of Nrf-2, its translocation to nucleus and activation of HO-1. Additionally, it activates adenylate cyclase resulting in cAMP formation which in turn activates protein kinase A leading to inhibition of GSK-3β by phosphorylation. Inactivated GSK-3β leads to retention of Nrf-2 in the nucleus leading to sustained expression of HO-1 by binding to its antioxidant response element (ARE). Thus, andrographolide probably by binding to adenosine A2a receptor activates Nrf-2 transcription and also inhibits its exclusion from the nucleus by inactivating GSK-3β, together resulting in activation of HO-1. We speculate that andrographolide can be used as a therapeutic drug to combat oxidative stress implicated in pathogenesis of various diseases such as diabetes, osteoporosis, neurodegenerative diseases etc. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Trimetazidine protects retinal ganglion cells from acute glaucoma via the Nrf2/Ho-1 pathway.

    Science.gov (United States)

    Wan, Peixing; Su, Wenru; Zhang, Yingying; Li, Zhidong; Deng, Caibin; Zhuo, Yehong

    2017-09-15

    Acute glaucoma is one of the leading causes of irreversible vision impairment characterized by the rapid elevation of intraocular pressure (IOP) and consequent retinal ganglion cell (RGC) death. Oxidative stress and neuroinflammation have been considered critical for the pathogenesis of RGC death in acute glaucoma. Trimetazidine (TMZ), an anti-ischemic drug, possesses antioxidative and anti-inflammatory properties, contributing to its therapeutic potential in tissue damage. However, the role of TMZ in acute glaucoma and the underlying molecular mechanisms remain elusive. Here, we report that treatment with TMZ significantly attenuated retinal damage and RGC death in mice with acute glaucoma, with a significant decrease in reactive oxygen species (ROS) and inflammatory cytokine production in the retina. Furthermore, TMZ treatment directly decreased ROS production and rebalanced the intracellular redox state, thus contributing to the survival of RGCs in vitro TMZ treatment also reduced the production of inflammatory cytokines in vitro Mechanistically, the TMZ-mediated inhibition of apoptosis and inflammatory cytokine production in RGCs occurred via the regulation of the nuclear factor erythroid 2-related factor 2/heme oxygenase 1/caspase-8 pathway. Moreover, the TMZ-mediated neuroprotection in acute glaucoma was abrogated when an HO-1 inhibitor, SnPP, was used. Our findings identify potential mechanisms of RGC apoptosis and propose a novel therapeutic agent, TMZ, which exerts a precise neuroprotective effect against acute glaucoma. © 2017 The Author(s).

  2. Fucoxanthin enhances HO-1 and NQO1 expression in murine hepatic BNL CL.2 cells through activation of the Nrf2/ARE system partially by its pro-oxidant activity.

    Science.gov (United States)

    Liu, Cheng-Ling; Chiu, Yu-Ting; Hu, Miao-Lin

    2011-10-26

    To determine whether fucoxanthin, a major carotenoid in brown sea algae, may activate cellular antioxidant enzymes via up-regulation of the Nrf2/antioxidant-response element (ARE) pathway, we incubated mouse hepatic BNL CL.2 cells with fucoxanthin (0.5-20 μM) for 0-24 h. We found that fucoxanthin (≥5 μM) significantly increased cellular reactive oxygen species (ROS) at 6 h of incubation, whereas preincubation with α-d-tocopherol (30 μM) significantly attenuated the increase of ROS, indicating the pro-oxidant nature of fucoxanthin. Fucoxanthin significantly increased the phosphorylation of ERK and p38 and markedly increased nuclear Nrf2 protein accumulation after incubation for 12 h. Moreover, fucoxanthin significantly enhanced binding activities of nuclear Nrf2 with ARE and increased mRNA and protein expression of HO-1 and NQO1 after incubation for 12 h. siRNA inhibition of Nrf2 led to markedly decreased HO-1 and NQO1 protein expression. Thus, fucoxanthin may exert its antioxidant activity, at least partly, through its pro-oxidant actions.

  3. Activation of Nrf2/HO-1 Pathway by Glycogen Synthase Kinase-3β Inhibition Attenuates Renal Ischemia/Reperfusion Injury in Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Xiaohua Shen

    2017-06-01

    Full Text Available Background/Aims: Diabetes mellitus can exacerbate renal ischemia-reperfusion (I/R injury (RI/RI. The aim of the present study was to evaluate the protective effect of GSK-3β inhibition (TDZD-8 on I/R-induced renal injury through the Nrf2/HO-1 pathway in a streptozocin (STZ-induced diabetic rat model. Methods: STZ-induced diabetic rats preconditioned with TDZD-8 and ZnPP were subjected to renal I/R. The extent of renal morphologic lesions. Renal function was assessed from blood urea nitrogen (BUN and serum creatinine (Scr, as determined utlizing commercial kits. Oxidative stress and inflammatory activity in the kidney tissue was estimated from levels of malondialdehyde (MDA, interleukin-10 (IL-10, tumor necrosis factor-α (TNF-α, and nitric oxide (NO, as well as the activities of superoxide dismutase (SOD and glutathione (GSH using qRT-PCR and ELISA. The expressions of Nrf2, HO-1, Bcl-2 and NF-κB in the renal tissue were measured by qRT-PCR and western blotting. Results: I/R-induced renal inflammation was reduced significantly by TDZD-8 pretreatment. Preconditioning with TDZD-8 suppressed NF-κB expression and enhanced Bcl-2 expression in the renal tissue. The upregulated level of malondialdehyde (MDA, and reduced activities of superoxide dismutase (SOD and glutathione (GSH in I/R-shocked rats were markedly restored by TDZD-8 pretreatment. Furthermore, pretreatment with TDZD-8 enhanced activation of the Nrf2/HO-1 pathway in the renal tissue of diabetic RI/RI rats. Conclusion: These findings suggest that preconditioning with TDZD-8 may protect the kidney from I/R-induced damage via the activation of the Nrf2/HO-1 pathway in STZ-induced diabetic rats. Further detailed studies are needed to further clarify the underlying mechanisms.

  4. Glaucocalyxin B Alleviates Lipopolysaccharide-Induced Parkinson’s Disease by Inhibiting TLR/NF-κB and Activating Nrf2/HO-1 Pathway

    Directory of Open Access Journals (Sweden)

    Wei Xu

    2017-12-01

    Full Text Available Background/Aims: Parkinson’s disease (PD is a common neurodegenerative disease in the old population, characterized by dopaminergic neuron loss, inflammation and oxidative stress injury in the substantia nigra. Glaucocalyxin B (GLB, an ent-kauranoid diterpenoid isolated from Rabdosia japonica, has anti-inflammation and anti-tumor effects. However, its effects on PD remain unclear. Methods: PD was introduced in rats via injection of lipopolysaccharide (LPS into cerebral corpus striatum, and GLB was given intracerebroventricularly to these rats. Their walking, climbing and sensory states were detected by Stepping, Whisker and Cylinder Tests. The expression of tyrosine hydroxylase (TH, glial fibrillary acidic protein (GFAP, CD11b and ionized calcium binding adaptor molecule (IBA-1 were detected by immunohischemical staining. The levels of a series of inflammatory factors, oxidative stress-related factors and apoptosis-related factors were measured by real-time PCR, immunoblotting and ELISA. In addition, Toll-like receptor (TLR/nuclear factor kappa B (NF-κB and nuclear factor erythroid 2-related factor 2 (Nrf2/heme oxygenase (HO-1 pathways were investigated to illustrate the underlying mechanism. In vitro, microglial cells exposed to LPS were treated with GLB. Results: The injection of LPS caused walking, climbing and sensory disturbances in rats, induced inflammation, oxidative stress response and apoptosis, and activated TLR/NF-κB and Nrf2/ HO-1 pathways in the cerebral tissue. GLB administration attenuated LPS-induced alterations. The TLR/NF-κB pathway was deactivated and Nrf2/HO-1 was activated after application of GLB. In vitro, cytotoxic effects induced by the conditioned medium derived from microglial cells exposed to LPS in PC12 cells were attenuated by GLB. Conclusion: GLB suppresses LPS-induced PD symptoms by modification of TLR/NF-κB and Nrf2/HO-1 pathways in vivo and in vitro.

  5. Sulforaphane exerts its anti-inflammatory effect against amyloid-β peptide via STAT-1 dephosphorylation and activation of Nrf2/HO-1 cascade in human THP-1 macrophages.

    Science.gov (United States)

    An, Ye Won; Jhang, Kyoung A; Woo, So-Youn; Kang, Jihee Lee; Chong, Young Hae

    2016-02-01

    Alzheimer's disease (AD) is the most common neurodegenerative disorder worldwide, accounting for most cases of dementia in elderly individuals, and effective therapies are still lacking. This study was designed to investigate the anti-inflammatory properties of sulforaphane against Aβ1-42 monomers in human THP-1 microglia-like cells. The results showed that sulforaphane preferentially inhibited cathepsin B- and caspase-1-dependent NLRP3 inflammasome activation induced by mostly Aβ1-42 monomers, an effect that potently reduced excessive secretion of the proinflammatory cytokine interleukin-1β (IL-1β). Subsequent mechanistic studies revealed that sulforaphane mitigated the activation of signal transducer and activator of transcription-1 induced by Aβ1-42 monomers. Sulforaphane also increased nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation, which was followed by upregulation of heme-oxygenase 1 (HO-1). The anti-inflammatory effect of sulforaphane on Aβ1-42-induced IL-1β production was diminished by small interfering RNA-mediated knockdown of Nrf2 or HO-1. Moreover, sulforaphane significantly attenuated the levels of microRNA-146a, which is selectively upregulated in the temporal cortex and hippocampus of AD brains. The aforementioned effects of sulforaphane were replicated by the tyrosine kinase inhibitor, herbimycin A, and Nrf2 activator. These results indicate that signal transducer and activator of transcription-1 dephosphorylation, HO-1 and its upstream effector, Nrf2, play a pivotal role in triggering an anti-inflammatory signaling cascade of sulforaphane that results in decreases of IL-1β release and microRNA-146a production in Aβ1-42-stimulated human microglia-like cells. These findings suggest that the phytochemical sulforaphane has a potential application in AD therapeutics. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Sofalcone, a gastric mucosa protective agent, increases vascular endothelial growth factor via the Nrf2-heme-oxygenase-1 dependent pathway in gastric epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Shibuya, Akiko [Department of Clinical Pharmacology, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Onda, Kenji, E-mail: knjond@toyaku.ac.jp [Department of Clinical Pharmacology, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Kawahara, Hirofumi; Uchiyama, Yuka; Nakayama, Hiroko; Omi, Takamasa; Nagaoka, Masayoshi [Department of Clinical Pharmacology, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Matsui, Hirofumi [Division of Gastroenterology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Ten-nohdai, Tsukuba, Ibaraki 305-8575 (Japan); Hirano, Toshihiko [Department of Clinical Pharmacology, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan)

    2010-07-30

    Research highlights: {yields} Sofalcone increases HO-1 in gastric epithelial cells. {yields} The induction of HO-1 by sofalcone treatment follows the activation of Nrf2. {yields} The production of VEGF by sofalcone treatment is mediated by HO-1 induction. -- Abstract: Sofalcone, 2'-carboxymethoxy-4,4-bis(3-methyl-2-butenyloxy)chalcone, is an anti-ulcer agent that is classified as a gastric mucosa protective agent. Recent studies indicate heat shock proteins such as HSP32, also known as heme-oxygenase-1(HO-1), play important roles in protecting gastrointestinal tissues from several stresses. We have previously reported that sofalcone increases the expression of HO-1 in adipocytes and pre-adipocytes, although the effect of sofalcone on HO-1 induction in gastrointestinal tissues is not clear. In the current study, we investigated the effects of sofalcone on the expression of HO-1 and its functional role in rat gastric epithelial (RGM-1) cells. We found that sofalcone increased HO-1 expression in RGM-1 cells in both time- and concentration-dependent manners. The HO-1 induction was associated with the nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in RGM-1 cells. We also observed that sofalcone increased vascular endothelial growth factor (VEGF) production in the culture medium. Treatment of RGM-1 cells with an HO-1 inhibitor (tin-protoporphyrin), or HO-1 siRNA inhibited sofalcone-induced VEGF production, suggesting that the effect of sofalcone on VEGF expression is mediated by the HO-1 pathway. These results suggest that the gastroprotective effects of sofalcone are partly exerted via Nrf2-HO-1 activation followed by VEGF production.

  7. Antihepatocarcinoma Effect of Portulaca oleracea L. in Mice by PI3K/Akt/mTOR and Nrf2/HO-1/NF-κB Pathway

    Science.gov (United States)

    Guoyin, Zheng; Hao, Peng; Min, Li; Wei, Gu; Zhe, Chen

    2017-01-01

    The purpose of the present study was to evaluate the pharmacological effects of Portulaca oleracea L. (Purslane) (PL) on N-nitrosodiethylamine- (NDEA-) induced hepatocellular carcinomas (HCC) and explore its potential mechanism. Mice were randomly assigned to four groups: control group, NDEA group, NDEA + Purslane (100 mg/kg) group, and NDEA + Purslane (200 mg/kg) group. The animal of each group was given NDEA (100 ppm) in drinking water. 1 h later, Purslane dissolved in PBS was intragastrically administered for continuous seven days. The results showed that Purslane reduced the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in liver and serum. Purslane also reduced the contents of interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α), and methane dicarboxylic aldehyde (MDA) and restored the activity of superoxygen dehydrogenises (SOD) in serum. Purslane could obviously attenuate the hepatic pathological alteration. Furthermore, treatment with Purslane effectively inhibited the phosphorylations of phosphatidylinositol 3 kinase (PI3K), protein kinase B (Akt), mammalian target of rapamycin (mTOR), nuclear factor-kappa B (NF-κB), and inhibitor of NF-κBα (IκBα) and upregulated the expressions of NF-E2-related factor 2 (Nrf2) and heme oxygenase- (HO-) 1. In conclusion, our research suggested that Purslane exhibited protective effects on NDEA-induced hepatocellular carcinomas by anti-inflammatory and antioxidative properties via the PI3K/Akt/mTOR and Nrf2/HO-1/NF-κB pathway. PMID:28659990

  8. Synergistic cardioprotective effects of Danshensu and hydroxysafflor yellow A against myocardial ischemia-reperfusion injury are mediated through the Akt/Nrf2/HO-1 pathway

    Science.gov (United States)

    HU, TIANXIN; WEI, GUO; XI, MIAOMIAO; YAN, JIAJIA; WU, XIAOXIAO; WANG, YANHUA; ZHU, YANRONG; WANG, CHAO; WEN, AIDONG

    2016-01-01

    In clinical practice, the traditional Chinese medicinal herbs, Radix Salvia Miltiorrhiza and Carthamus tinctorius L., are usually prescribed in combination due to their significant cardioprotective effects. However, the mechanisms responsible for these combined effects remain unknown. Thus, in this study, we investigated the mechanisms responsible for the combined effects of Danshensu (DSS) and hydroxysafflor yellow A (HSYA) by establishing a rat model of myocardial ischemia/reperfusion (MI/R), as well as a model of hypoxia/reoxygenation (H/R) using H9c2 cells. The combination index (CI) was calculated using the median-effect method. DSS and HSYA in combination led to a CI value of ZnPP-IX), did not decrease the expression of p-Akt and Nrf2, although it abolished the anti-apoptotic and antioxidant effects of DSS and HSYA. The findings of our study thus demonstrate that DSS and HSYA confer synergistic cardioprotective effects through the Akt/Nrf2/HO-1 signaling pathway, to certain extent, by enhancing the antioxidant defense system and exerting anti-apoptotic effects. PMID:27176815

  9. Low concentration of 4-hydroxy hexenal increases heme oxygenase-1 expression through activation of Nrf2 and antioxidative activity in vascular endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Ishikado, Atsushi [Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science, Seta-Tsukinowa-Cho, Otsu, Shiga 520-2192 (Japan); Nishio, Yoshihiko, E-mail: nishio@belle.shiga-med.ac.jp [Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science, Seta-Tsukinowa-Cho, Otsu, Shiga 520-2192 (Japan); Morino, Katsutaro; Ugi, Satoshi; Kondo, Hajime [Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science, Seta-Tsukinowa-Cho, Otsu, Shiga 520-2192 (Japan); Makino, Taketoshi [Research and Development Department, Sunstar Inc., 3-1, Asahi-Machi, Takatsuki, Osaka 569-1195 (Japan); Kashiwagi, Atsunori; Maegawa, Hiroshi [Division of Endocrinology and Metabolism, Department of Medicine, Shiga University of Medical Science, Seta-Tsukinowa-Cho, Otsu, Shiga 520-2192 (Japan)

    2010-11-05

    Research highlights: {yields} Low doses of 4-HHE and 4-HNE induce HO-1 expression in vascular endothelial cells. {yields} 4-HHE and 4-HNE increase the intranuclear expression and DNA binding of Nrf2. {yields} 4-HHE and 4-HNE-induced HO-1 expression depends on the activation of Nrf2. {yields} Pretreatment with 4-HHE and 4-HNE prevents oxidative stress-induced cytotoxicity. -- Abstract: Large-scale clinical studies have shown that n-3 polyunsaturated fatty acids (n-3 PUFAs) such as eicosapentaenoic and docosahexaenoic acids reduce cardiovascular events without improving classical risk factors for atherosclerosis. Recent studies have proposed that direct actions of n-3 PUFAs themselves, or of their enzymatic metabolites, have antioxidative and anti-inflammatory effects on vascular cells. Although a recent study showed that plasma 4-hydroxy hexenal (4-HHE), a peroxidation product of n-3 PUFA, increased after supplementation of docosahexaenoic acid, the antiatherogenic effects of 4-HHE in vascular cells remain unclear. In the present study, we tested the hypothesis that 4-HHE induces the antioxidative enzyme heme oxygenase-1 (HO-1) through activation of nuclear factor erythroid 2-related factor 2 (Nrf2), a master regulatory transcriptional factor, and prevents oxidative stress-induced cytotoxicity in vascular endothelial cells. This mechanism could partly explain the cardioprotective effects of n-3 PUFAs. Human umbilical vein endothelial cells were stimulated with 1-10 {mu}M 4-HHE or 4-hydroxy nonenal (4-HNE), a peroxidation product of n-6 PUFAs. Both 4-HHE and 4-HNE dose-dependently increased HO-1 mRNA and protein expression, and intranuclear expression and DNA binding of Nrf2 at 5 {mu}M. Small interfering RNA for Nrf2 significantly reduced 4-HHE- or 4-HNE-induced HO-1 mRNA and protein expression. Furthermore, pretreatment with 4-HHE or 4-HNE prevented tert-butyl hydroperoxide-induced cytotoxicity. In conclusion, 4-HHE, a peroxidation product of n-3 PUFAs, stimulated

  10. Inhibition of microRNA-153 protects neurons against ischemia/reperfusion injury in an oxygen-glucose deprivation and reoxygenation cellular model by regulating Nrf2/HO-1 signaling.

    Science.gov (United States)

    Ji, Qiong; Gao, Jianbo; Zheng, Yan; Liu, Xueli; Zhou, Qiangqiang; Shi, Canxia; Yao, Meng; Chen, Xia

    2017-07-01

    MicroRNAs are emerging as critical regulators in cerebral ischemia/reperfusion injury; however, their exact roles remain poorly understood. miR-153 is reported to be a neuron-related miRNA involved in neuroprotection. In this study, we aimed to investigate the precise role of miR-153 in regulating neuron survival during cerebral ischemia/reperfusion injury using an oxygen-glucose deprivation and reoxygenation (OGD/R) cellular model. We found that miR-153 was significantly upregulated in neurons subjected to OGD/R treatment. Inhibition of miR-153 significantly attenuated OGD/R-induced injury and oxidative stress in neurons. Nuclear factor erythroid 2-related factor 2 (Nrf2) was identified as a target gene of miR-153. Inhibition of miR-153 significantly promoted the expression of Nrf2 and heme oxygenase-1 (HO-1). However, silencing of Nrf2 significantly blocked the protective effects of miR-153 inhibition. Our study indicates that the inhibition of miR-153 protects neurons against OGD/R-induced injury by regulating Nrf2/HO-1 signaling and suggests a potential therapeutic target for cerebral ischemia/reperfusion injury. © 2017 Wiley Periodicals, Inc.

  11. Hawthorn Fruit Extract Elevates Expression of Nrf2/HO-1 and Improves Lipid Profiles in Ovariectomized Rats

    Science.gov (United States)

    Yoo, Jeong-Hyun; Liu, Yanan; Kim, Hyun-Sook

    2016-01-01

    The purpose of this study was to investigate the effects of hawthorn (Crataegus pinnatifida Bunge) extract on the lipid profiles and antioxidant properties in ovariectomized (OVX) rats. After ovariectomy, the rats were randomly divided into four groups: the non-OVX control (Sham), the OVX-control (OVX), the OVX + 100 mg/kg b.w. of hawthorn extract (OL), and the OVX + 200 mg/kg b.w. of hawthorn extract (OH). The final body weights of the OVX group were significantly increased, but the increment was significantly decreased in hawthorn groups (p hawthorn groups showed a significant decrease in these levels (p hawthorn groups compared with the OVX group (p hawthorn groups exhibited a significant increase in expression (p hawthorn extract reversed the suppression of protein levels. These results suggest that hawthorn extract could have protective effects in OVX rats by improving lipid profiles, decreasing oxidative stress, and improving the antioxidant defense system. PMID:27187458

  12. Synergistic effects of dietary bioactive compounds and investigation of Nrf2/HO-1 axis in HIV-1 transgenic rat

    OpenAIRE

    Davinelli, Sergio

    2014-01-01

    Considerable evidence suggests that the combinatorial effect dietary bioactive compounds may be useful in preventing or reducing aging features. Therefore, a synergistic multi-target approach in dietary intervention may be effective in slowing down the aging process and increase healthy aging. Functional foods and nutraceuticals can exert specific anti-aging benefits such as improvement in mitochondrial function or induce neuroprotective effects to counteract the deleterious consequences of o...

  13. Andrographolide inhibits hypoxia-induced HIF-1α-driven endothelin 1 secretion by activating Nrf2/HO-1 and promoting the expression of prolyl hydroxylases 2/3 in human endothelial cells.

    Science.gov (United States)

    Lin, Hung-Chih; Su, Shih-Li; Lu, Chia-Yang; Lin, Ai-Hsuan; Lin, Wan-Chun; Liu, Chin-San; Yang, Ya-Chen; Wang, Hsiu-Miao; Lii, Chong-Kuei; Chen, Haw-Wen

    2017-03-01

    Andrographolide, the main bioactive component of the medicinal plant Andrographis paniculata, has been shown to possess potent anti-inflammatory activity. Endothelin 1 (ET-1), a potent vasoconstrictor peptide produced by vascular endothelial cells, displays proinflammatory property. Hypoxia-inducible factor 1α (HIF-1α), the regulatory member of the transcription factor heterodimer HIF-1α/β, is one of the most important molecules that responds to hypoxia. Changes in cellular HIF-1α protein level are the result of altered gene transcription and protein stability, with the latter being dependent on prolyl hydroxylases (PHDs). In this study, inhibition of pro-inflammatory ET-1 expression and changes of HIF-1α gene transcription and protein stability under hypoxia by andrographolide in EA.hy926 endothelial-like cells were investigated. Hypoxic conditions were created using the hypoxia-mimetic agent CoCl 2. We found that hypoxia stimulated the production of reactive oxygen species (ROS), the expression of HIF-1α mRNA and protein, and the expression and secretion of ET-1. These effects, however, were attenuated by co-exposure to andrographolide, bilirubin, and RuCO. Silencing Nrf2 and heme oxygenase 1 (HO-1) reversed the inhibitory effects of andrographolide on hypxoia-induced HIF-1α mRNA and protein expression. Moreover, andrographolide increased the expression of prolyl hydroxylases (PHD) 2/3, which hydroxylate HIF-1α and promotes HIF-1α proteasome degradation, with an increase in HIF-1α hydroxylation was noted under hypoxia. Inhibition of p38 MAPK abrogated the hypoxia-induced increases in HIF-1α mRNA and protein expression as well as ET-1 mRNA expression and secretion. Taken together, these results suggest that andrographolide suppresses hypoxia-induced pro-inflammatory ET-1 expression by activating Nrf2/HO-1, inhibiting p38 MAPK signaling, and promoting PHD2/3 expression. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 918-930, 2017. © 2016 Wiley

  14. Ginsenoside Rb1 protects against 6-hydroxydopamine-induced oxidative stress by increasing heme oxygenase-1 expression through an estrogen receptor-related PI3K/Akt/Nrf2-dependent pathway in human dopaminergic cells

    International Nuclear Information System (INIS)

    Hwang, Yong Pil; Jeong, Hye Gwang

    2010-01-01

    Phytoestrogens are polyphenolic non-steroidal plant compounds with estrogen-like biological activity. Ginseng, the root of Panax ginseng C.A. Meyer (Araliaceae), is a popular traditional herbal medicine. Ginsenoside Rb1 (Rb1), an active component commonly found in ginseng root, is a phytoestrogen that exerts estrogen-like activity. In this study, we demonstrate that the phytoestrogen Rb1 inhibits 6-hydroxydopamine (6-OHDA)-induced oxidative injury via an ER-dependent Gβ1/PI3K/Akt and heme oxygenase-1 (HO-1) pathway. Pretreatment of SH-SY5Y cells with Rb1 significantly reduced 6-OHDA-induced caspase-3 activation and subsequent cell death. Rb1 also up-regulated HO-1 expression, which conferred cytoprotection against 6-OHDA-induced oxidative injury. Moreover, Rb1 induced both Nrf2 nuclear translocation, which is upstream of HO-1 expression and PI3K activation, a pathway that is involved in induced Nrf2 nuclear translocation, HO-1 expression and cytoprotection. Also, Rb1-mediated increases in PI3K activation and HO-1 induction were reversed by co-treatment with ICI 182,780 and pertussis toxin. Taken together, these results suggest that Rb1 augments the cellular antioxidant defenses through ER-dependent HO-1 induction via the Gβ1/PI3K/Akt-Nrf2 signaling pathway, thereby protecting cells from oxidative stress. Thus our study indicates that Rb1 has a partial cytoprotective role in dopaminergic cell culture systems.

  15. Berberine protects against 6-OHDA-induced neurotoxicity in PC12 cells and zebrafish through hormetic mechanisms involving PI3K/AKT/Bcl-2 and Nrf2/HO-1 pathways.

    Science.gov (United States)

    Zhang, Chao; Li, Chuwen; Chen, Shenghui; Li, Zhiping; Jia, Xuejing; Wang, Kai; Bao, Jiaolin; Liang, Yeer; Wang, Xiaotong; Chen, Meiwan; Li, Peng; Su, Huanxing; Wan, Jian-Bo; Lee, Simon Ming Yuen; Liu, Kechun; He, Chengwei

    2017-04-01

    Berberine (BBR) is a renowned natural compound that exhibits potent neuroprotective activities. However, the cellular and molecular mechanisms are still unclear. Hormesis is an adaptive mechanism generally activated by mild oxidative stress to protect the cells from further damage. Many phytochemicals have been shown to induce hormesis. This study aims to investigate whether the neuroprotective activity of BBR is mediated by hormesis and the related signaling pathways in 6-OHDA-induced PC12 cells and zebrafish neurotoxic models. Our results demonstrated that BBR induced a typical hormetic response in PC12 cells, i.e. low dose BBR significantly increased the cell viability, while high dose BBR inhibited the cell viability. Moreover, low dose BBR protected the PC12 cells from 6-OHDA-induced cytotoxicity and apoptosis, whereas relatively high dose BBR did not show neuroprotective activity. The hormetic and neuroprotective effects of BBR were confirmed to be mediated by up-regulated PI3K/AKT/Bcl-2 cell survival and Nrf2/HO-1 antioxidative signaling pathways. In addition, low dose BBR markedly mitigated the 6-OHDA-induced dopaminergic neuron loss and behavior movement deficiency in zebrafish, while high dose BBR only slightly exhibited neuroprotective activities. These results strongly suggested that the neuroprotection of BBR were attributable to the hormetic mechanisms via activating cell survival and antioxidative signaling pathways. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  16. Berberine protects against 6-OHDA-induced neurotoxicity in PC12 cells and zebrafish through hormetic mechanisms involving PI3K/AKT/Bcl-2 and Nrf2/HO-1 pathways

    Directory of Open Access Journals (Sweden)

    Chao Zhang

    2017-04-01

    Full Text Available Berberine (BBR is a renowned natural compound that exhibits potent neuroprotective activities. However, the cellular and molecular mechanisms are still unclear. Hormesis is an adaptive mechanism generally activated by mild oxidative stress to protect the cells from further damage. Many phytochemicals have been shown to induce hormesis. This study aims to investigate whether the neuroprotective activity of BBR is mediated by hormesis and the related signaling pathways in 6-OHDA-induced PC12 cells and zebrafish neurotoxic models. Our results demonstrated that BBR induced a typical hormetic response in PC12 cells, i.e. low dose BBR significantly increased the cell viability, while high dose BBR inhibited the cell viability. Moreover, low dose BBR protected the PC12 cells from 6-OHDA-induced cytotoxicity and apoptosis, whereas relatively high dose BBR did not show neuroprotective activity. The hormetic and neuroprotective effects of BBR were confirmed to be mediated by up-regulated PI3K/AKT/Bcl-2 cell survival and Nrf2/HO-1 antioxidative signaling pathways. In addition, low dose BBR markedly mitigated the 6-OHDA-induced dopaminergic neuron loss and behavior movement deficiency in zebrafish, while high dose BBR only slightly exhibited neuroprotective activities. These results strongly suggested that the neuroprotection of BBR were attributable to the hormetic mechanisms via activating cell survival and antioxidative signaling pathways.

  17. (-)-7(S)-hydroxymatairesinol protects against tumor necrosis factor-α-mediated inflammation response in endothelial cells by blocking the MAPK/NF-κB and activating Nrf2/HO-1.

    Science.gov (United States)

    Yang, Di; Xiao, Chen-Xi; Su, Zheng-Hua; Huang, Meng-Wei; Qin, Ming; Wu, Wei-Jun; Jia, Wan-Wan; Zhu, Yi-Zhun; Hu, Jin-Feng; Liu, Xin-Hua

    2017-08-15

    Endothelial inflammation is an increasingly prevalent condition in the pathogenesis of many cardiovascular diseases. (-)-7(S)-hydroxymatairesinol (7-HMR), a naturally occurring plant lignan, possesses both antioxidant and anti-cancer properties and therefore would be a good strategy to suppress tumor necrosis factor-α (TNF-α)-mediated inflammation in vascular endothelial cells (VECs). The objective of this study is to evaluate for its anti-inflammatory effect on TNF-α-stimulated VECs and underling mechanisms. The effect of the 7-HMR on suppression of TNF-α-induced inflammation mediators in VECs were determined by qRT-PCR and Western blot. MAPKs and phosphorylation of Akt, HO-1 and NF-κB p65 were examined using Western blot. Nuclear localisation of NF-κB was also examined using Western blot and immunofluorescence. Here we found that 7-HMR could suppress TNF-α-induced inflammatory mediators, such as vascularcelladhesion molecule-1, interleukin-6 and inducible nitric oxide synthase expression both in mRNA and protein levels, and concentration-dependently attenuated reactive oxidase species generation. We further identified that 7-HMR remarkably induced superoxide dismutase and heme oxygenase-1 expression associated with degradation of Kelch-like ECH-associated protein 1 (keap1) and up-regulated nuclear factor erythroid 2-related factor 2 (Nrf2). In addition, 7-HMR time- and concentration-dependently attenuated TNF-α-induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK) and Akt, but not p38, or c-Jun N-terminal kinase 1/2. Moreover, 7-HMR significantly suppressed TNF-α-mediated nuclear factor-κB (NF-κB) activation by inhibiting phosphorylation and nuclear translocation of NF-κB p65. Our results demonstrated that 7-HMR inhibited TNF-α-stimulated endothelial inflammation, at least in part, through inhibition of NF-κB activation and upregulation of Nrf2-antioxidant response element signaling pathway, suggesting 7-HMR might be used as a

  18. Role of the Nrf2-heme oxygenase-1 pathway in silver nanoparticle-mediated cytotoxicity

    International Nuclear Information System (INIS)

    Kang, Su Jin; Ryoo, In-geun; Lee, Young Joon; Kwak, Mi-Kyoung

    2012-01-01

    Silver nanoparticles (nano-Ag) have been widely used in various commercial products including textiles, electronic appliances and biomedical products. However, there remains insufficient information on the potential risk of nano-Ag to human health and environment. In the current study, we have investigated the role of NF-E2-related factor 2 (Nrf2) transcription factor in nano-Ag-induced cytotoxicity. When Nrf2 expression was blocked using interring RNA expression in ovarian carcinoma cell line, nano-Ag treatment showed a substantial decrease in cell viability with concomitant increases in apoptosis and DNA damage compared to the control cells. Target gene analysis revealed that the expression of heme oxygenase-1 (HO-1) was highly elevated by nano-Ag in nonspecific shRNA expressing cells, while Nrf2 knockdown cells (NRF2i) did not increase HO-1 expression. The role of HO-1 in cytoprotection against nano-Ag was reinforced by results using pharmacological inducer of HO-1: cobalt protoporphyrin-mediated HO-1 activation in the NRF2i cells prevented nano-Ag-mediated cell death. Similarly, pharmacological or genetic inhibition of HO-1 in nonspecific control cells exacerbated nano-Ag toxicity. As the upstream signaling mechanism, nano-Ag required the phosphoinositide 3-kinase (PI3K) and p38MAPK signaling cascades for HO-1 induction. The treatment with either PI3K inhibitor or p38MAPK inhibitor suppressed HO-1 induction and intensified nano-Ag-induced cell death. Taken together, these results suggest that Nrf2-dependent HO-1 up-regulation plays a protective role in nano-Ag-induced DNA damage and consequent cell death. In addition, nano-Ag-mediated HO-1 induction is associated with the PI3K and p38MAPK signaling pathways. -- Highlights: ► Role of Nrf2 signaling in silver nanoparticle toxicity. ► Silver nanoparticle toxicity is increased by Nrf2 blockade. ► Nrf2-dependent HO-1 induction protects cells from silver nanoparticle toxicity. ► PI3K and p38MAPK cascades are

  19. Epalrestat increases glutathione, thioredoxin, and heme oxygenase-1 by stimulating Nrf2 pathway in endothelial cells

    Directory of Open Access Journals (Sweden)

    Kaori Yama

    2015-04-01

    Full Text Available Epalrestat (EPS is the only aldose reductase inhibitor that is currently available for the treatment of diabetic neuropathy. Recently, we found that EPS at near-plasma concentration increases the intracellular levels of glutathione (GSH in rat Schwann cells. GSH plays a crucial role in protecting endothelial cells from oxidative stress, thereby preventing vascular diseases. Here we show that EPS increases GSH levels in not only Schwann cells but also endothelial cells. Treatment of bovine aortic endothelial cells (BAECs, an in vitro model of the vascular endothelium, with EPS caused a dramatic increase in intracellular GSH levels. This was concomitant with the up-regulation of glutamate cysteine ligase, an enzyme catalyzing the first and rate-limiting step in de novo GSH synthesis. Moreover, EPS stimulated the expression of thioredoxin and heme oxygenase-1, which have important redox regulatory functions in endothelial cells. Nuclear factor erythroid 2-related factor 2 (Nrf2 is a key transcription factor that regulates the expression of antioxidant genes. EPS increased nuclear Nrf2 levels in BAECs. Nrf2 knockdown by siRNA suppressed the EPS-induced glutamate cysteine ligase, thioredoxin-1, and heme oxygenase-1 expression. Interestingly, LY294002, an inhibitor of phosphatidylinositol 3-kinase, abolished the EPS-stimulated GSH synthesis, suggesting that the kinase is associated with Nrf2 activation induced by EPS. Furthermore, EPS reduced the cytotoxicity induced by H2O2 and tert-butylhydroperoxide, indicating that EPS plays a role in protecting cells from oxidative stress. Taken together, the results provide evidence that EPS exerts new beneficial effects on endothelial cells by increasing GSH, thioredoxin, and heme oxygenase-1 levels through the activation of Nrf2. We suggest that EPS has the potential to prevent several vascular diseases caused by oxidative stress.

  20. Mitigation of radiation induced hematopoietic injury via regulation of Nrf-2 and increasing hematopoietic stem cells

    International Nuclear Information System (INIS)

    Patwardhan, R.S.; Sharma, Deepak; Checker, Rahul; Santosh Kumar, S.

    2014-01-01

    Therapeutic doses of ionizing radiation (IR) that can be delivered to tumors are restricted due to radiation induced damage to surrounding normal tissues thereby limiting the effectiveness of radiotherapy. Strategies to develop agents that selectively protect normal cells yielded limited success in the past. There is pressing need to develop safe, syndrome specific and effective radiation countermeasures to prevent or mitigate the harmful consequences of radiation exposure. Survival of bone marrow stem cells (HSCs) play a key role in protecting against IR induced hematopoietic injury. Many studies have shown manipulation of HSC frequency and/or survival as principal mechanism of radioprotection. It is known that, Nrf-2 plays crucial role in HSC survival and maintenance under oxidative stress conditions. In the present study, we have investigated the radioprotective ability of a flavonoid baicalein (5,6,7-trihydroxyflavone), extracted from the root of Scutellaria baicalensis Georgi, a medicinal plant traditionally used in Oriental medicine. There are numerous reports showing anti-inflammatory, anti-apoptotic, anti-oxidant, anti-cancer, anti-microbial, anti-mutagenic and neuroprotective properties of baicalein. Based on these reports, we have investigated the ability of baicalein to protect against radiation induced hematopoietic injury. Baicalein administration to mice protected against WBI induced mortality. Interestingly, the stem cell frequency increased in bone marrow cells obtained from baicalein administered mice as compared to vehicle treated mice. Baicalein treatment led to increased phospho-Nrf-2 levels in lineage negative BM-MNC. Administration of mice with Nrf-2 inhibitor prior to baicalein treatment led to significant abrogation of radioprotective ability of baicalein. This result suggests that, Nrf-2 may be playing a key role in baicalein mediated radioprotection. Here, we have shown that baicalein administration augments stem cell frequency, induces

  1. Cordyceps sinensis increases hypoxia tolerance by inducing heme oxygenase-1 and metallothionein via Nrf2 activation in human lung epithelial cells.

    Science.gov (United States)

    Singh, Mrinalini; Tulsawani, Rajkumar; Koganti, Praveen; Chauhan, Amitabh; Manickam, Manimaran; Misra, Kshipra

    2013-01-01

    Cordyceps sinensis, an edible mushroom growing in Himalayan regions, is widely recognized in traditional system of medicine. In the present study, we report the efficacy of Cordyceps sinensis in facilitating tolerance to hypoxia using A549 cell line as a model system. Treatment with aqueous extract of Cordyceps sinensis appreciably attenuated hypoxia induced ROS generation, oxidation of lipids and proteins and maintained antioxidant status similar to that of controls via induction of antioxidant gene HO1 (heme oxygenase-1), MT (metallothionein) and Nrf2 (nuclear factor erythroid-derived 2-like 2). In contrast, lower level of NF κ B (nuclear factor kappaB) and tumor necrosis factor- α observed which might be due to higher levels of HO1, MT and transforming growth factor- β . Further, increase in HIF1 (hypoxia inducible factor-1) and its regulated genes; erythropoietin, vascular endothelial growth factor, and glucose transporter-1 was observed. Interestingly, Cordyceps sinensis treatment under normoxia did not regulate the expression HIF1, NF κ B and their regulated genes evidencing that Cordyceps sinensis per se did not have an effect on these transcription factors. Overall, Cordyceps sinensis treatment inhibited hypoxia induced oxidative stress by maintaining higher cellular Nrf2, HIF1 and lowering NF κ B levels. These findings provide a basis for possible use of Cordyceps sinensis in tolerating hypoxia.

  2. Lipoxin A4-induced heme oxygenase-1 protects cardiomyocytes against hypoxia/reoxygenation injury via p38 MAPK activation and Nrf2/ARE complex.

    Directory of Open Access Journals (Sweden)

    Xiao-Qing Chen

    Full Text Available To investigate whether lipoxin A4 (LXA4 increases expression of heme oxygenase-1(HO-1 in cardiomyocytes, whether LXA4-induced HO-1 protects cardiomyocytes against hypoxia/reoxygenation (H/R injury, and what are the mechanisms involved in the LXA4-induced HO-1 induction.Rat cardiomyocytes were exposed to H/R injury with or without preincubation with LXA4 or HO-1 inhibitor ZnPP-IX or various signal molecule inhibitors. Expressions of HO-1 protein and mRNA were analyzed by using Western blot and RT-PCR respectively. Activity of nuclear factor E2-related factor 2 (Nrf2 binding to the HO-1 E1 enhancer was assessed by chromatin immunoprecipitation. Nrf2 binding to the HO-1 antioxidant responsive element (ARE were measured by using electrophoretic mobility shift assay.Pretreatment of the cells undergoing H/R lesion with LXA4 significantly reduced the lactate dehydrogenase and creatine kinase productions, increased the cell viability, and increased the expressions of HO-1 protein and mRNA and HO-1 promoter activity. HO-1 inhibition abolished the protective role of LXA4 on the cells undergoing H/R lesion. LXA4 increased p38 mitogen-activated protein kinase (p38 MAPK activation, nuclear translocation of Nrf2, Nrf2 binding to the HO-1 ARE and E1 enhancer in cardiomyocytes with or without H/R exposure.The protection role of LXA4 against H/R injury of cardiomyocytes is related to upregulation of HO-1, via activation of p38 MAPK pathway and nuclear translocation of Nrf2 and Nrf2 binding to the HO-1 ARE and E1 enhancer, but not via activation of phosphatidyinositol-3-kinase or extracellular signal-regulated kinase pathway.

  3. Andrographolide inhibits TNFα-induced ICAM-1 expression via suppression of NADPH oxidase activation and induction of HO-1 and GCLM expression through the PI3K/Akt/Nrf2 and PI3K/Akt/AP-1 pathways in human endothelial cells.

    Science.gov (United States)

    Lu, Chia-Yang; Yang, Ya-Chen; Li, Chien-Chun; Liu, Kai-Li; Lii, Chong-Kuei; Chen, Haw-Wen

    2014-09-01

    Andrographolide, the major bioactive component of Andrographis paniculata, has been demonstrated to have various biological properties including anti-inflammation, antioxidation, and anti-hepatotoxicity. Oxidative stress is considered a major risk factor in aging, inflammation, cancer, atherosclerosis, and diabetes mellitus. NADPH oxidase is a major source of endogenous reactive oxygen species (ROS). In this study, we used EA.hy926 endothelial-like cells to explore the anti-inflammatory activity of andrographolide. Andrographolide attenuated TNFα-induced ROS generation, Src phosphorylation, membrane translocation of the NADPH oxidase subunits p47(phox) and p67(phox), and ICAM-1 gene expression. In the small hairpin RNA interference assay, shp47(phox) abolished TNFα-induced p65 nuclear translocation, ICAM-1 gene expression, and adhesion of HL-60 cells. Andrographolide induced the gene expression of heme oxygenase 1 (HO-1) and glutamate cysteine ligase modifier subunit (GCLM) in a time-dependent manner. Cellular glutathione (GSH) content was increased by andrographolide. shGCLM attenuated the andrographolide-induced increase in GSH content and reversed the andrographolide inhibition of HL-60 adhesion. shHO-1 showed a similar effect on andrographolide inhibition of HL-60 adhesion to shGCLM. The mechanism underlying the up-regulation of HO-1 and GCLM by andrographolide was dependent on the PI3K/Akt pathway, and both the Nrf2 and AP-1 transcriptional factors were involved. Our results suggest that andrographolide attenuates TNFα-induced ICAM-1 expression at least partially through suppression of NADPH oxidase activation and induction of HO-1 and GCLM expression, which is PI3K/Akt pathway-dependent. Copyright © 2014. Published by Elsevier Inc.

  4. Omeprazole induces heme oxygenase-1 in fetal human pulmonary microvascular endothelial cells via hydrogen peroxide-independent Nrf2 signaling pathway.

    Science.gov (United States)

    Patel, Ananddeep; Zhang, Shaojie; Shrestha, Amrit Kumar; Maturu, Paramahamsa; Moorthy, Bhagavatula; Shivanna, Binoy

    2016-11-15

    Omeprazole (OM) is an aryl hydrocarbon receptor (AhR) agonist and a proton pump inhibitor that is used to treat humans with gastric acid related disorders. Recently, we showed that OM induces NAD (P) H quinone oxidoreductase-1 (NQO1) via nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent mechanism. Heme oxygenase-1 (HO-1) is another cytoprotective and antioxidant enzyme that is regulated by Nrf2. Whether OM induces HO-1 in fetal human pulmonary microvascular endothelial cells (HPMEC) is unknown. Therefore, we tested the hypothesis that OM will induce HO-1 expression via Nrf2 in HPMEC. OM induced HO-1 mRNA and protein expression in a dose-dependent manner. siRNA-mediated knockdown of AhR failed to abrogate, whereas knockdown of Nrf2 abrogated HO-1 induction by OM. To identify the underlying molecular mechanisms, we determined the effects of OM on cellular hydrogen peroxide (H 2 O 2 ) levels since oxidative stress mediated by the latter is known to activate Nrf2. Interestingly, the concentration at which OM induced HO-1 also increased H 2 O 2 levels. Furthermore, H 2 O 2 independently augmented HO-1 expression. Although N-acetyl cysteine (NAC) significantly decreased H 2 O 2 levels in OM-treated cells, we observed that OM further increased HO-1 mRNA and protein expression in NAC-pretreated compared to vehicle-pretreated cells, suggesting that OM induces HO-1 via H 2 O 2 -independent mechanisms. In conclusion, we provide evidence that OM transcriptionally induces HO-1 via AhR - and H 2 O 2 - independent, but Nrf2 - dependent mechanisms. These results have important implications for human disorders where Nrf2 and HO-1 play a beneficial role. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Resveratrol Prevents Diabetic Cardiomyopathy by Increasing Nrf2 Expression and Transcriptional Activity

    Directory of Open Access Journals (Sweden)

    Guan Wang

    2018-01-01

    Full Text Available Objective. This study investigated if resveratrol ameliorates diabetic cardiomyopathy by targeting associated oxidative stress mechanisms. Method. Type 1 diabetes mellitus (DM in FVB mice was induced by several intraperitoneal injections of a low dose of streptozotocin. Hyperglycemic and age-matched control mice were given resveratrol (10 mg/kg per day for 1 month and subsequently monitored for an additional 6 months. Mice were assigned to four groups: control, resveratrol, DM, and DM/resveratrol. Cardiac function and blood pressure were assessed at 1, 3, and 6 months after DM induction. Oxidative damage and cardiac fibrosis were analyzed by histopathology, real-time PCR, and Western blot. Result. Mice in the DM group exhibited increased blood glucose levels, cardiac dysfunction, and high blood pressure at 1, 3, and 6 months after DM induction. Resveratrol did not significantly affect blood glucose levels and blood pressure; however, resveratrol attenuated cardiac dysfunction and hypertrophy in DM mice. Resveratrol also reduced DM-induced fibrosis. In addition, DM mice hearts exhibited increased oxidative damage, as evidenced by elevated accumulation of 3-nitrotyrosine and 4-hydroxynonenal, which were both attenuated by resveratrol. Mechanistically, resveratrol increased NFE2-related factor 2 (Nrf2 expression and transcriptional activity, as well as Nrf2’s downstream antioxidative targets. Conclusion. We demonstrated that resveratrol prevents DM-induced cardiomyopathy, in part, by increasing Nrf2 expression and transcriptional activity.

  6. Decreased histone deacetylase 2 impairs Nrf2 activation by oxidative stress

    International Nuclear Information System (INIS)

    Mercado, Nicolas; Thimmulappa, Rajesh; Thomas, Catherine M.R.; Fenwick, Peter S.; Chana, Kirandeep K.; Donnelly, Louise E.; Biswal, Shyam; Ito, Kazuhiro; Barnes, Peter J.

    2011-01-01

    Research highlights: → Nrf2 anti-oxidant function is impaired when HDAC activity is inhibited. → HDAC inhibition decreases Nrf2 protein stability. → HDAC2 is involved in reduced Nrf2 stability and both correlate in COPD samples. → HDAC inhibition increases Nrf2 acetylation. -- Abstract: Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a crucial role in cellular defence against oxidative stress by inducing the expression of multiple anti-oxidant genes. However, where high levels of oxidative stress are observed, such as chronic obstructive pulmonary disease (COPD), Nrf2 activity is reduced, although the molecular mechanism for this defect is uncertain. Here, we show that down-regulation of histone deacetylase (HDAC) 2 causes Nrf2 instability, resulting in reduced anti-oxidant gene expression and increase sensitivity to oxidative stress. Although Nrf2 protein was clearly stabilized after hydrogen peroxide (H 2 O 2 ) stimulation in a bronchial epithelial cell line (BEAS2B), Nrf2 stability was decreased and Nrf2 acetylation increased in the presence of an HDAC inhibitor, trichostatin A (TSA). TSA also reduced Nrf2-regulated heme-oxygenase-1 (HO-1) expression in these cells, and this was confirmed in acute cigarette-smoke exposed mice in vivo. HDAC2 knock-down by RNA interference resulted in reduced H 2 O 2 -induced Nrf2 protein stability and activity in BEAS2B cells, whereas HDAC1 knockdown had no effect. Furthermore, monocyte-derived macrophages obtained from healthy volunteers (non-smokers and smokers) and COPD patients showed a significant correlation between HDAC2 expression and Nrf2 expression (r = 0.92, p < 0.0001). Thus, reduced HDAC2 activity in COPD may account for increased Nrf2 acetylation, reduced Nrf2 stability and impaired anti oxidant defences.

  7. Decreased histone deacetylase 2 impairs Nrf2 activation by oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Mercado, Nicolas [Airway Disease Section, National Heart and Lung Institute, Imperial College, London SW3 6LY (United Kingdom); Thimmulappa, Rajesh [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD (United States); Thomas, Catherine M.R.; Fenwick, Peter S.; Chana, Kirandeep K.; Donnelly, Louise E. [Airway Disease Section, National Heart and Lung Institute, Imperial College, London SW3 6LY (United Kingdom); Biswal, Shyam [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD (United States); Ito, Kazuhiro [Airway Disease Section, National Heart and Lung Institute, Imperial College, London SW3 6LY (United Kingdom); Barnes, Peter J., E-mail: p.j.barnes@imperial.ac.uk [Airway Disease Section, National Heart and Lung Institute, Imperial College, London SW3 6LY (United Kingdom)

    2011-03-11

    Research highlights: {yields} Nrf2 anti-oxidant function is impaired when HDAC activity is inhibited. {yields} HDAC inhibition decreases Nrf2 protein stability. {yields} HDAC2 is involved in reduced Nrf2 stability and both correlate in COPD samples. {yields} HDAC inhibition increases Nrf2 acetylation. -- Abstract: Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a crucial role in cellular defence against oxidative stress by inducing the expression of multiple anti-oxidant genes. However, where high levels of oxidative stress are observed, such as chronic obstructive pulmonary disease (COPD), Nrf2 activity is reduced, although the molecular mechanism for this defect is uncertain. Here, we show that down-regulation of histone deacetylase (HDAC) 2 causes Nrf2 instability, resulting in reduced anti-oxidant gene expression and increase sensitivity to oxidative stress. Although Nrf2 protein was clearly stabilized after hydrogen peroxide (H{sub 2}O{sub 2}) stimulation in a bronchial epithelial cell line (BEAS2B), Nrf2 stability was decreased and Nrf2 acetylation increased in the presence of an HDAC inhibitor, trichostatin A (TSA). TSA also reduced Nrf2-regulated heme-oxygenase-1 (HO-1) expression in these cells, and this was confirmed in acute cigarette-smoke exposed mice in vivo. HDAC2 knock-down by RNA interference resulted in reduced H{sub 2}O{sub 2}-induced Nrf2 protein stability and activity in BEAS2B cells, whereas HDAC1 knockdown had no effect. Furthermore, monocyte-derived macrophages obtained from healthy volunteers (non-smokers and smokers) and COPD patients showed a significant correlation between HDAC2 expression and Nrf2 expression (r = 0.92, p < 0.0001). Thus, reduced HDAC2 activity in COPD may account for increased Nrf2 acetylation, reduced Nrf2 stability and impaired anti oxidant defences.

  8. Estrogen increases Nrf2 activity through activation of the PI3K pathway in MCF-7 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Juanjuan, E-mail: jwu32@emory.edu [Department of Gynecology and Obstetrics, Emory University School of Medicine, 101 Woodruff Circle, Suite 4211 WMB, Atlanta, GA 30322 (United States); Williams, Devin [Department of Obstetrics and Gynecology, Morehouse School of Medicine, Atlanta, GA 30310 (United States); Walter, Grant A. [Department of Gynecology and Obstetrics, Emory University School of Medicine, 101 Woodruff Circle, Suite 4211 WMB, Atlanta, GA 30322 (United States); Thompson, Winston E. [Department of Obstetrics and Gynecology, Morehouse School of Medicine, Atlanta, GA 30310 (United States); Sidell, Neil [Department of Gynecology and Obstetrics, Emory University School of Medicine, 101 Woodruff Circle, Suite 4211 WMB, Atlanta, GA 30322 (United States)

    2014-11-01

    The actions of the transcription factor Nuclear factor erythroid 2-related factor (Nrf2) in breast cancer have been shown to include both pro-oncogenic and anti-oncogenic activities which is influenced, at least in part, by the hormonal environment. However, direct regulation of Nrf2 by steroid hormones (estrogen and progesterone) has received only scant attention. Nrf2 is known to be regulated by its cytosolic binding protein, Kelch-like ECH-associated protein 1 (Keap1), and by a Keap1-independent mechanism involving a series of phosphorylation steps mediated by phosphatidylinositol 3-kinase (PI3K) and glycogen synthase kinase 3 beta (GSK3β). Here, we report that estrogen (E2) increases Nrf2 activity in MCF7 breast cancer cells through activation of the PI3K/GSK3β pathway. Utilizing antioxidant response element (ARE)-containing luciferase reporter constructs as read-outs for Nrf2 activity, our data indicated that E2 increased ARE activity >14-fold and enhanced the action of the Nrf2 activators, tertiary butylhydroquinone (tBHQ) and sulforaphane (Sul) 4 to 9 fold compared with cells treated with tBHQ or Sul as single agents. This activity was shown to be an estrogen receptor-mediated phenomenon and was antagonized by progesterone. In addition to its action on the reporter constructs, mRNA and protein levels of heme oxygenase 1, an endogenous target gene of Nrf2, was markedly upregulated by E2 both alone and in combination with tBHQ. Importantly, E2-induced Nrf2 activation was completely suppressed by the PI3K inhibitors LY294002 and Wortmannin while the GSK3β inhibitor CT99021 upregulated Nrf2 activity. Confirmation that E2 was, at least partly, acting through the PI3K/GSK3β pathway was indicated by our finding that E2 increased the phosphorylation status of both GSK3β and Akt, a well-characterized downstream target of PI3K. Together, these results demonstrate a novel mechanism by which E2 can regulate Nrf2 activity in estrogen receptor-positive breast cancer

  9. Regulation of hemeoxygenase-1 gene expression by Nrf2 and c-Jun in tertiary butylhydroquinone-stimulated rat primary astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin-Sun; Kim, Hee-Sun, E-mail: hskimp@ewha.ac.kr

    2014-05-16

    Highlights: • tBHQ increased HO-1 mRNA and protein levels in rat primary astrocytes. • tBHQ enhanced HO-1 gene transcription in an ARE-dependent manner. • tBHQ increased the nuclear translocation and DNA binding of Nrf2 and c-Jun to ARE. • Nrf2 and c-Jun are involved in the differential modulation of HO-1 expression. • Nrf2 and c-Jun regulate HO-1 expression via their coordinated interaction. - Abstract: Hemeoxygenase-1 (HO-1) is a phase II antioxidant enzyme that is primarily involved in detoxification and cytoprotection in a variety of tissues. However, the mechanism underlying HO-1 gene expression remains unclear. In the present study, we investigated the regulation of HO-1 expression in primary cultured astrocytes by using the natural antioxidant compound tertiary butylhydroquinone (tBHQ). We found that tBHQ increased HO-1 mRNA and protein levels. Promoter analysis revealed that tBHQ enhanced HO-1 gene transcription in an antioxidant response element (ARE)-dependent manner. In addition, tBHQ increased the nuclear translocation and DNA binding of Nrf2 and c-Jun to ARE. Small interfering RNA (siRNA) experiments demonstrated that Nrf2 and c-Jun are involved in the differential modulation of HO-1 expression. Thus, Nrf2 knockdown reduced the basal level of HO-1 expression but did not affect the fold induction by tBHQ. On the other hand, knockdown of c-Jun diminished tBHQ-mediated induction of HO-1 without affecting basal expression. The data suggest that Nrf2 generally modulates the basal expression of HO-1, while c-Jun mediates HO-1 induction in response to tBHQ. The results of co-immunoprecipitation assays demonstrated a physical interaction between Nrf2 and c-Jun in tBHQ-treated astrocytes. The results suggest that Nrf2 and c-Jun regulate HO-1 expression via their coordinated interaction in tBHQ-treated rat primary astrocytes.

  10. Regulation of hemeoxygenase-1 gene expression by Nrf2 and c-Jun in tertiary butylhydroquinone-stimulated rat primary astrocytes

    International Nuclear Information System (INIS)

    Park, Jin-Sun; Kim, Hee-Sun

    2014-01-01

    Highlights: • tBHQ increased HO-1 mRNA and protein levels in rat primary astrocytes. • tBHQ enhanced HO-1 gene transcription in an ARE-dependent manner. • tBHQ increased the nuclear translocation and DNA binding of Nrf2 and c-Jun to ARE. • Nrf2 and c-Jun are involved in the differential modulation of HO-1 expression. • Nrf2 and c-Jun regulate HO-1 expression via their coordinated interaction. - Abstract: Hemeoxygenase-1 (HO-1) is a phase II antioxidant enzyme that is primarily involved in detoxification and cytoprotection in a variety of tissues. However, the mechanism underlying HO-1 gene expression remains unclear. In the present study, we investigated the regulation of HO-1 expression in primary cultured astrocytes by using the natural antioxidant compound tertiary butylhydroquinone (tBHQ). We found that tBHQ increased HO-1 mRNA and protein levels. Promoter analysis revealed that tBHQ enhanced HO-1 gene transcription in an antioxidant response element (ARE)-dependent manner. In addition, tBHQ increased the nuclear translocation and DNA binding of Nrf2 and c-Jun to ARE. Small interfering RNA (siRNA) experiments demonstrated that Nrf2 and c-Jun are involved in the differential modulation of HO-1 expression. Thus, Nrf2 knockdown reduced the basal level of HO-1 expression but did not affect the fold induction by tBHQ. On the other hand, knockdown of c-Jun diminished tBHQ-mediated induction of HO-1 without affecting basal expression. The data suggest that Nrf2 generally modulates the basal expression of HO-1, while c-Jun mediates HO-1 induction in response to tBHQ. The results of co-immunoprecipitation assays demonstrated a physical interaction between Nrf2 and c-Jun in tBHQ-treated astrocytes. The results suggest that Nrf2 and c-Jun regulate HO-1 expression via their coordinated interaction in tBHQ-treated rat primary astrocytes

  11. Anti-neuroinflammatory Activity of Elephantopus scaber L. via Activation of Nrf2/HO-1 Signaling and Inhibition of p38 MAPK Pathway in LPS-Induced Microglia BV-2 Cells

    Directory of Open Access Journals (Sweden)

    Chim-Kei Chan

    2017-06-01

    Full Text Available Elephantopus scaber L. (family: Asteraceae has been traditionally utilized as a folkloric medicine and scientifically shown to exhibit anti-inflammatory activities in various in vivo inflammatory models. Given the lack of study on the effect of E. scaber in neuroinflammation, this study aimed to investigate the anti-neuroinflammatory effect and the underlying mechanisms of ethyl acetate fraction from the leaves of E. scaber (ESEAF on the release of pro-inflammatory mediators in lipopolysaccharide (LPS-induced microglia cells (BV-2. Present findings showed that ESEAF markedly attenuated the translocation of NF-κB to nucleus concomitantly with the significant mitigation on the LPS-induced production of NO, iNOS, COX-2, PGE2, IL-1β, and TNF-α. These inflammatory responses were reduced via the inhibition of p38. Besides, ESEAF was shown to possess antioxidant activities evident by the DPPH and SOD scavenging activities. The intracellular catalase enzyme activity was enhanced by ESEAF in the LPS-stimulated BV-2 cells. Furthermore, the formation of ROS induced by LPS in BV-2 cells was reduced upon the exposure to ESEAF. Intriguingly, the reduction of ROS was found in concerted with the activation of Nrf2 and HO-1. It is conceivable that the activation promotes the scavenging power of antioxidant enzymes as well as to ameliorate the inflammatory response in LPS-stimulated BV-2 cells. Finally, the safety profile analysis through oral administration of ESEAF at 2000 mg/kg did not result in any mortalities, adverse effects nor histopathologic abnormalities of organs in mice. Taken altogether, the cumulative findings suggested that ESEAF holds the potential to develop as nutraceutical for the intervention of neuroinflammatory disorders.

  12. Aldose Reductase Inhibitor Protects against Hyperglycemic Stress by Activating Nrf2-Dependent Antioxidant Proteins

    Directory of Open Access Journals (Sweden)

    Kirtikar Shukla

    2017-01-01

    Full Text Available We have shown earlier that pretreatment of cultured cells with aldose reductase (AR inhibitors prevents hyperglycemia-induced mitogenic and proinflammatory responses. However, the effects of AR inhibitors on Nrf2-mediated anti-inflammatory responses have not been elucidated yet. We have investigated how AR inhibitor fidarestat protects high glucose- (HG- induced cell viability changes by increasing the expression of Nrf2 and its dependent phase II antioxidant enzymes. Fidarestat pretreatment prevents HG (25 mM-induced Thp1 monocyte viability. Further, treatment of Thp1 monocytes with fidarestat caused a time-dependent increase in the expression as well as the DNA-binding activity of Nrf2. In addition, fidarestat augmented the HG-induced Nrf2 expression and activity and also upregulated the expression of Nrf2-dependent proteins such as hemeoxygenase-1 (HO1 and NQO1 in Thp1 cells. Similarly, treatment with AR inhibitor also induced the expression of Nrf2 and HO1 in STZ-induced diabetic mice heart and kidney tissues. Further, AR inhibition increased the HG-induced expression of antioxidant enzymes such as SOD and catalase and activation of AMPK-α1 in Thp1 cells. Our results thus suggest that pretreatment with AR inhibitor prepares the monocytes against hyperglycemic stress by overexpressing the Nrf2-dependent antioxidative proteins.

  13. Aldose Reductase Inhibitor Protects against Hyperglycemic Stress by Activating Nrf2-Dependent Antioxidant Proteins.

    Science.gov (United States)

    Shukla, Kirtikar; Pal, Pabitra Bikash; Sonowal, Himangshu; Srivastava, Satish K; Ramana, Kota V

    2017-01-01

    We have shown earlier that pretreatment of cultured cells with aldose reductase (AR) inhibitors prevents hyperglycemia-induced mitogenic and proinflammatory responses. However, the effects of AR inhibitors on Nrf2-mediated anti-inflammatory responses have not been elucidated yet. We have investigated how AR inhibitor fidarestat protects high glucose- (HG-) induced cell viability changes by increasing the expression of Nrf2 and its dependent phase II antioxidant enzymes. Fidarestat pretreatment prevents HG (25 mM)-induced Thp1 monocyte viability. Further, treatment of Thp1 monocytes with fidarestat caused a time-dependent increase in the expression as well as the DNA-binding activity of Nrf2. In addition, fidarestat augmented the HG-induced Nrf2 expression and activity and also upregulated the expression of Nrf2-dependent proteins such as hemeoxygenase-1 (HO1) and NQO1 in Thp1 cells. Similarly, treatment with AR inhibitor also induced the expression of Nrf2 and HO1 in STZ-induced diabetic mice heart and kidney tissues. Further, AR inhibition increased the HG-induced expression of antioxidant enzymes such as SOD and catalase and activation of AMPK- α 1 in Thp1 cells. Our results thus suggest that pretreatment with AR inhibitor prepares the monocytes against hyperglycemic stress by overexpressing the Nrf2-dependent antioxidative proteins.

  14. Cytoprotective Role of Nrf2 in Electrical Pulse Stimulated C2C12 Myotube.

    Directory of Open Access Journals (Sweden)

    Masaki Horie

    Full Text Available Regular physical exercise is central to a healthy lifestyle. However, exercise-related muscle contraction can induce reactive oxygen species and reactive nitrogen species (ROS/RNS production in skeletal muscle. The nuclear factor-E2-related factor-2 (Nrf2 transcription factor is a cellular sensor for oxidative stress. Regulation of nuclear Nrf2 signaling regulates antioxidant responses and protects organ structure and function. However, the role of Nrf2 in exercise- or contraction-induced ROS/RNS production in skeletal muscle is not clear. In this study, using differentiated C2C12 cells and electrical pulse stimulation (EPS of muscle contraction, we explored whether Nrf2 plays a role in the skeletal muscle response to muscle contraction-induced ROS/RNS. We found that EPS (40 V, 1 Hz, 2 ms stimulated ROS/RNS accumulation and Nrf2 activation. We also showed that expression of NQO1, HO-1 and GCLM increased after EPS-induced muscle contraction and was remarkably suppressed in cells with Nrf2 knockdown. We also found that the antioxidant N-acetylcysteine (NAC significantly attenuated Nrf2 activation after EPS, whereas the nitric oxide synthetase inhibitor Nω-nitro-L-arginine methyl ester (L-NAME did not. Furthermore, Nrf2 knockdown after EPS markedly decreased ROS/RNS redox potential and cell viability and increased expression of the apoptosis marker Annexin V in C2C12 myotubes. These results indicate that Nrf2 activation and expression of Nrf2 regulated-genes protected muscle against the increased ROS caused by EPS-induced muscle contraction. Thus, our findings suggest that Nrf2 may be a key factor for preservation of muscle function during muscle contraction.

  15. Keap1 cysteine 288 as a potential target for diallyl trisulfide-induced Nrf2 activation.

    Directory of Open Access Journals (Sweden)

    Sanghyun Kim

    Full Text Available Diallyl sulfide, diallyl disulfide, and daillyl trisulfide (DATS are major volatile components of garlic oil. In this study, we assessed their relative potency in inducing antioxidant enzyme expression. Among the three organosulfur compounds, DATS was found to be most potent in inducing heme oxygenase-1 (HO-1 andquinone oxidoreductase-1 (NQO1 in human gastric epithelial (AGS cells. Furthermore, DATS administration by gavage increased the expression of HO-1 and NQO1 in C57BL/6 mouse stomach. Treatment with DATS increased the accumulation of nuclear factor-erythroid-2-related factor-2 (Nrf2 in the nucleus of cultured AGS cells and in mouse stomach in vivo. The DATS-induced expression of HO-1 and NQO1 was abrogated in the cells transiently transfected with Nrf2-siRNA or in the embryonic fibroblasts from Nrf2-null mice, indicating that Nrf2 is a key mediator of the cytoprotective effects of DATS. Pretreatment of AGS cells with N-acetylcysteine or dithiothreitol attenuated DATS-induced nuclear localization of Nrf2 and the expression of HO-1 and NQO1. Cysteine-151, -273 and -288 of Kelch-like ECH-associated protein-1 (Keap1, a cytosolic repressor of Nrf2, have been considered to act as a redox sensor and play a role in Nrf2 activation. To determine whether DATS could inactivate Keap1 through thiol modification, we established cell lines constitutively expressing wild type-Keap1 or three different mutant constructs in which cysteine-151, -273, or -288 of Keap1 was replaced with serine by retroviral gene transfer. DATS failed to activate Nrf2, and to induce expression of HO-1 and NQO1 only in Keap1-C288S mutant cells. LC-ESI-MS/MS analysis of recombinant Keap1 treated with DATS revealed that the peptide fragment containing Cys288 gained a molecular mass of 72.1 Da equivalent to the molecular weight of mono-allyl mono-sulfide. Taken together, these findings suggest that DATS may directly interact with the Cys288 residue of Keap1, which partly accounts

  16. Methionine sulfoxide reductase B3 deficiency stimulates heme oxygenase-1 expression via ROS-dependent and Nrf2 activation pathways

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Geun-Hee; Kim, Ki Young; Kim, Hwa-Young, E-mail: hykim@ynu.ac.kr

    2016-05-13

    Methionine sulfoxide reductase B3 (MsrB3), which is primarily found in the endoplasmic reticulum (ER), is an important protein repair enzyme that stereospecifically reduces methionine-R-sulfoxide residues. We previously found that MsrB3 deficiency arrests the cell cycle at the G{sub 1}/S stage through up-regulation of p21 and p27. In this study, we report a critical role of MsrB3 in gene expression of heme oxygenase-1 (HO-1), which has an anti-proliferative effect associated with p21 up-regulation. Depletion of MsrB3 elevated HO-1 expression in mammalian cells, whereas MsrB3 overexpression had no effect. MsrB3 deficiency increased cellular reactive oxygen species (ROS), particularly in the mitochondria. ER stress, which is associated with up-regulation of HO-1, was also induced by depletion of MsrB3. Treatment with N-acetylcysteine as an ROS scavenger reduced augmented HO-1 levels in MsrB3-depleted cells. MsrB3 deficiency activated Nrf2 transcription factor by enhancing its expression and nuclear import. The activation of Nrf2 induced by MsrB3 depletion was confirmed by increased expression levels of its other target genes, such as γ-glutamylcysteine ligase. Taken together, these data suggest that MsrB3 attenuates HO-1 induction by inhibiting ROS production, ER stress, and Nrf2 activation. -- Highlights: •MsrB3 depletion induces HO-1 expression. •MsrB3 deficiency increases cellular ROS and ER stress. •MsrB3 deficiency activates Nrf2 by increasing its expression and nuclear import. •MsrB3 attenuates HO-1 induction by inhibiting ROS production and Nrf2 activation.

  17. Upregulation of heme oxygenase-1 expression by dehydrodiconiferyl alcohol (DHCA) through the AMPK–Nrf2 dependent pathway

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Junghun; Kim, Sunyoung, E-mail: sunyoung@snu.ac.kr

    2014-11-15

    Oxidative stress is induced by the accumulation of free radicals, resulting in an imbalanced cellular redox state, which has been implicated in a variety of human diseases. Dehydrodiconiferyl alcohol (DHCA), a lignan compound isolated from Cucurbita moschata, has previously been reported to contain anti-adipogenic and anti-lipogenic effects on 3T3-L1 cells and primary MEFs (Abraham and Kappas, 2008). In this study, it was tested whether DHCA could affect the expression of HO-1, using Raw264.7 mouse macrophage cell line. DHCA increased the protein and RNA levels of HO-1 and upregulated its promoter activity. Data from transient transfection assays indicated that ARE located in the E1 region of the HO-1 promoter are important in this DHCA-mediated induction of HO-1 expression. DHCA was also shown to enhance the nuclear translocation and binding of Nrf2 to the respective DNA sequences. The upregulation of HO-1 expression by DHCA was also observed in primary macrophages derived from wild type animals, but not in those from Nrf2 KO mice. Effects of DHCA on HO-1 and Nrf2 were reduced when cells were treated with an AMPK inhibitor, Compound C, but not by PI3K/Akt or MAPK inhibitors. Data from an experiment using a specific siRNA or chemical inhibitor for HO-1 suggested that the DHCA-mediated induction of the HO-1 protein could suppress the LPS-stimulated production of NO. Taken together, our data suggest that DHCA induces the expression of HO-1 by controlling its promoter activity through the AMPK–Nrf2 pathway, eventually leading to the reduction of NO production, and may thus have potential as an effective antioxidant. - Highlights: • Dehydrodiconiferyl alcohol (DHCA) induced the expression of heme oxygenase (HO)-1. • The AMPK–Nrf2 pathway is critically involved in the DHCA-mediated induction of HO-1. • DHCA increased the expression of HO-1, Gclc and Gclm in primary macrophages. • DHCA-mediated induction of HO-1 contributed to the suppression of NO production.

  18. Increased Energy Expenditure, Ucp1 Expression, and Resistance to Diet-induced Obesity in Mice Lacking Nuclear Factor-Erythroid-2-related Transcription Factor-2 (Nrf2).

    Science.gov (United States)

    Schneider, Kevin; Valdez, Joshua; Nguyen, Janice; Vawter, Marquis; Galke, Brandi; Kurtz, Theodore W; Chan, Jefferson Y

    2016-04-01

    The NRF2 (also known as NFE2L2) transcription factor is a critical regulator of genes involved in defense against oxidative stress. Previous studies suggest thatNrf2plays a role in adipogenesisin vitro, and deletion of theNrf2gene protects against diet-induced obesity in mice. Here, we demonstrate that resistance to diet-induced obesity inNrf2(-/-)mice is associated with a 20-30% increase in energy expenditure. Analysis of bioenergetics revealed thatNrf2(-/-)white adipose tissues exhibit greater oxygen consumption. White adipose tissue showed a >2-fold increase inUcp1gene expression. Oxygen consumption is also increased nearly 2.5-fold inNrf2-deficient fibroblasts. Oxidative stress induced by glucose oxidase resulted in increasedUcp1expression. Conversely, antioxidant chemicals (such asN-acetylcysteine and Mn(III)tetrakis(4-benzoic acid)porphyrin chloride) and SB203580 (a known suppressor ofUcp1expression) decreasedUcp1and oxygen consumption inNrf2-deficient fibroblasts. These findings suggest that increasing oxidative stress by limitingNrf2function in white adipocytes may be a novel means to modulate energy balance as a treatment of obesity and related clinical disorders. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Novel cytoprotective mechanism of anti-parkinsonian drug deprenyl: PI3K and Nrf2-derived induction of antioxidative proteins

    International Nuclear Information System (INIS)

    Nakaso, Kazuhiro; Nakamura, Chiharu; Sato, Hiromi; Imamura, Keiko; Takeshima, Takao; Nakashima, Kenji

    2006-01-01

    Neuroprotection has received considerable attention as a strategy for the treatment of Parkinson's disease (PD). Deprenyl (Selegiline) is a promising candidate for neuroprotection; however, its cytoprotective mechanism has not been fully clarified. Here, we report a novel cytoprotective mechanism of deprenyl involving PI3K and Nrf2-mediated induction of oxidative stress-related proteins. Deprenyl increased the expression of HO-1, PrxI, TrxI, TrxRxI, γGCS, and p62/A170 in SH-SY5Y cells. Deprenyl also induced the nuclear accumulation of Nrf2 and increased the binding activity of Nrf2 to the enhancer region of human genomic HO-1. The Nrf2-mediated induction of antioxidative molecules was controlled by PI3K. Indeed, furthermore, neurotrophin receptor TrkB was identified as an upstream signal for PI3K-Nrf2 activation by deprenyl. These results suggest that the cytoprotective effect of deprenyl is, in part, dependent on Nrf2-mediated induction of antioxidative proteins, suggesting that activation of the PI3K-Nrf2 system may be a useful therapeutic strategy for PD

  20. Metallothionein-III protects against 6-hydroxydopamine-induced oxidative stress by increasing expression of heme oxygenase-1 in a PI3K and ERK/Nrf2-dependent manner

    International Nuclear Information System (INIS)

    Hwang, Yong Pil; Kim, Hyung Gyun; Han, Eun Hee; Jeong, Hye Gwang

    2008-01-01

    The zinc-binding protein metallothionein-III (MT-III) is associated with resistance to neuronal injury. However, the underlying mechanism for its effects is unclear. In this study, we demonstrate that MT-III prevents the accumulation of reactive oxygen species (ROS) in dopaminergic SH-SY5Y cells challenged with the Parkinson's disease-related neurotoxin 6-hydroxydopamine (6-OHDA) by a mechanism that involves phosphatidylinositol 3-kinase (PI3K) and ERK kinase/NF-E2-related factor 2 (Nrf2) dependent induction of the stress response protein heme oxygenase-1 (HO-1). Pretreatment of SH-SY5Y cells with MT-III significantly reduced 6-OHDA-induced generation of ROS, caspase-3 activation, and subsequent cell death. Also, MT-III up-regulates HO-1 expression and this expression confers neuroprotection against oxidative injury induced by 6-OHDA. Moreover, MT-III induces Nrf2 nuclear translocation, which is upstream of MT-III-induced HO-1 expression, and PI3K and ERK1/2 activation, a pathway that is involved in induced Nrf2 nuclear translocation, HO-1 expression and neuroprotection. Taken together, these results suggest that the PI3K and ERK/Nrf2 signaling pathway controls the intracellular levels of ROS by regulating the expression of the antioxidant enzyme HO-1

  1. Requirement and epigenetics reprogramming of Nrf2 in suppression of tumor promoter TPA-induced mouse skin cell transformation by sulforaphane.

    Science.gov (United States)

    Su, Zheng-Yuan; Zhang, Chengyue; Lee, Jong Hun; Shu, Limin; Wu, Tien-Yuan; Khor, Tin Oo; Conney, Allan H; Lu, Yao-Ping; Kong, Ah-Ng Tony

    2014-03-01

    Nrf2 is a transcription factor that plays critical roles in regulating the expression of cellular defensive antioxidants and detoxification enzymes. However, the role of Nrf2 and Nrf2's epigenetics reprogramming in skin tumor transformation is unknown. In this study, we investigated the inhibitory role and epigenetics of Nrf2 on tumor transformation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in mouse skin epidermal JB6 (JB6 P+) cells and the anticancer effect of sulforaphane (SFN), an isothiocyanate found in cruciferous vegetables. After five days of treatment, SFN significantly inhibited TPA-induced JB6 cellular transformation and SFN enhanced the nuclear translocation of Nrf2 and increased the mRNA and protein levels of the Nrf2 target genes HO-1, NQO1 and UGT1A1. Knockdown of Nrf2 attenuated the induction of Nrf2, HO-1 and NQO1 by SFN, enhanced TPA-induced colony formation and dampened the inhibitory effect of SFN on TPA-induced JB6 transformation. Epigenetics investigation using bisulfite genomic sequencing showed that SFN decreased the methylation ratio of the first 15 CpGs of the Nrf2 gene promoter, which was corroborated by increased Nrf2 mRNA expression. Furthermore, SFN strongly reduced the protein expression of DNA methyltransferases (DNMT1, DNMT3a and DNMT3b). SFN also inhibited the total histone deacetylase (HDAC) activity and decreased the protein expression of HDAC1, HDAC2, HDAC3 and HDAC4. Collectively, these results suggest that the anti-cancer effect of SFN against TPA-induced neoplastic transformation of mouse skin could involve the epigenetic reprogramming of anti-cancer genes such as Nrf2, leading to the epigenetic reactivation of Nrf2 and the subsequent induction of downstream target genes involved in cellular protection.

  2. Reactive oxygen species and PI3K/Akt signaling play key roles in the induction of Nrf2-driven heme oxygenase-1 expression in sulforaphane-treated human mesothelioma MSTO-211H cells.

    Science.gov (United States)

    Lee, Yoon-Jin; Jeong, Hyang-Yun; Kim, Yong-Bae; Lee, Yong-Jin; Won, Seong Youn; Shim, Jung-Hyun; Cho, Moon-Kyun; Nam, Hae-Seon; Lee, Sang-Han

    2012-02-01

    The nuclear factor erythroid-derived 2 related factor 2 (Nrf2)/heme oxygenase (HO)-1 induction plays cytoprotective roles against oxidative injury, apoptosis, and anticancer therapy; however, little is known about its regulation in human mesothelioma MSTO-211H cells. In this study, we investigated Nrf2/HO-1 induction in response to sulforaphane and determined the signaling pathways involved in this process. Sulforaphane treatment decreased cell viability and triggered a rapid and transient increase in the intracellular ROS levels. Pretreatment with N-acetylcysteine (NAC) prevented sulforaphane-induced cytotoxicity. Erk1/2 was activated within 1h of sulforaphane addition, whereas Akt phosphorylation was suppressed until the first 8h, and was then maintained at an elevated level until 72h, displaying a biphasic regulatory feature. Nrf2 protein levels in both nuclear and whole cell lysates were increased after sulforaphane treatment and were decreased by pretreatment with NAC, actinomycin D and cycloheximide. Activation of the Nrf2/HO-1 system after sulforaphane treatment was suppressed by pretreatment with NAC or Ly294002, a PI3K inhibitor. Knockdown of Nrf2 with siRNA decreased cell viability and attenuated sulforaphane-induced HO-1 up-regulation. Overall, our results indicate that ROS generation and/or activation of PI3K/Akt signaling regulate cell survival and Nrf2-driven HO-1 expression in sulforaphane-treated MSTO-211H cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Troxerutin Reduces Kidney Damage against BDE-47-Induced Apoptosis via Inhibiting NOX2 Activity and Increasing Nrf2 Activity

    Directory of Open Access Journals (Sweden)

    Qun Shan

    2017-01-01

    Full Text Available 2,2,4,4-Tetrabromodiphenyl ether (BDE-47, one of the persistent organic pollutants, seriously influences the quality of life; however, its pathological mechanism remains unclear. Troxerutin is a flavonoid with pharmacological activity of antioxidation and anti-inflammation. In the present study, we investigated troxerutin against BDE-47-induced kidney cell apoptosis and explored the underlying mechanism. The results show that troxerutin reduced renal cell apoptosis and urinary protein secretion in BDE-47-treated mice. Western blot analysis shows that troxerutin supplement enhanced the ratio of Bcl-2/Bax; inhibited the release of cytochrome c from mitochondria, the activation of procaspase-9 and procaspase-3, and the cleavage of PARP; and reduced FAS, FASL, and caspase-8 levels induced by BDE-47. In addition, troxerutin decreased the production of reactive oxygen species (ROS and increased the activities of antioxidative enzymes. Furthermore, troxerutin blunted Nrf2 ubiquitylation, enhanced the activity of Nrf2, decreased the activity of NOX2, and ameliorated kidney oxidant status of BDE-47-treated mice. Together, these results confirm that troxerutin could alleviate the cytotoxicity of BDE-47 through antioxidation and antiapoptosis, which suggests that its protective mechanism is involved in the inhibition of apoptosis via suppressing NOX2 activity and increasing Nrf2 signaling pathway.

  4. n-Butyl-α-D-fructofuranoside Isolated from Ulmus davidiana Enhances Nrf2 Activity Through Activation of JNK.

    Science.gov (United States)

    Choi, Hee-Jin; Choi, Hee-Jung; Park, Mi-Joo; Chung, Tae-Wook; Joo, Myungsoo; Kim, Cheorl-Ho; Chang, Hyun-Wook; Son, Jong-Keun; Ha, Ki-Tae

    The root bark of Ulmus davidiana Nakai (Ulmaceae), a traditional Korean medicinal plant, is used for treating inflammatory diseases. We investigated the Nrf2-activating effect of U. davidiana and identified a novel Nrf2 activator from its constituent compounds. Cytotoxicity was measured by MTT assay, and the Nrf2 activity was examined by luciferasereporter assay and western blot analysis. The expression of Nrf2-dependent antioxidant genes was estimated by RT-PCR. The signal pathway related to Nrf2 activation was analyzed by treating specific signaling inhibitors. Anti-inflammatory effects were determined using an NO assay and western blot analysis. Ulmus davidiana and its constituent compounds, including catechin-3-O-α-L-rhamnopyranoside, α-nigerose, n-butyl α-D-fructofuranoside (NBF), and procyanidin B3, enhanced the transcriptional activity of Nrf2. Of these compounds, only NBF possessed a distinctive structure and exhibited ROS-independent Nrf2 activation. In addition, NBF significantly increased the nuclear translocation of Nrf2 and the expression of Nrf2-dependent detoxifying enzymes, including HO-1 and NQO-1, in dose-dependent manner. The Nrf2 activation induced by NBF was mediated by the phosphorylation of JNK. Consequently, pretreatment with NBF inhibited the LPS-induced expression of pro-inflammatory genes. To the best of our knowledge, this is the first study to report on the Nrf2-activating effect of U. davidiana and NBF. Given the importance of Nrf2 as a negative regulator in various inflammatory diseases, NBF could be considered as a novel candidate for the prevention and treatment of inflammatory diseases.

  5. Resveratrol, an Nrf2 activator, ameliorates aging-related progressive renal injury.

    Science.gov (United States)

    Kim, Eun Nim; Lim, Ji Hee; Kim, Min Young; Ban, Tae Hyun; Jang, In-Ae; Yoon, Hye Eun; Park, Cheol Whee; Chang, Yoon Sik; Choi, Bum Soon

    2018-01-11

    Two important issues in the aging kidney are mitochondrial dysfunction and oxidative stress. An Nrf2 activator, resveratrol, is known to have various effects. Resveratrol may prevent inflammation and oxidative stress by activating Nrf2 and SIRT1 signaling. We examined whether resveratrol could potentially ameliorate the cellular condition, such as renal injury due to cellular oxidative stress and mitochondrial dysfunction caused by aging. Male 18-month-old C57BL/6 mice were used. Resveratrol (40 mg/kg) was administered to aged mice for 6 months. We compared histological changes, oxidative stress, and aging-related protein expression in the kidney between the resveratrol-treated group (RSV) and the control group (cont). We performed experiments using small-interfering RNAs (siRNAs) for Nrf2 and SIRT1 in cultured HK2 cells. Resveratrol improved renal function, proteinuria, histological changes and inflammation in aging mice. Also, expression of Nrf2-HO-1-NOQ-1 signaling and SIRT1-AMPK-PGC-1α signaling was increased in the RSV group. Transfection with Nrf2 and SIRT1 siRNA prevented resveratrol-induced anti-oxidative effect in HK2 cells in media treated with H 2 O 2 . Activation of the Nrf2 and SIRT1 signaling pathways ameliorated oxidative stress and mitochondrial dysfunction. Pharmacological targeting of Nrf2 signaling molecules may reduce the pathologic changes of aging in the kidney.

  6. Bardoxolone methyl (BARD) ameliorates aristolochic acid (AA)-induced acute kidney injury through Nrf2 pathway

    International Nuclear Information System (INIS)

    Wu, Juan; Liu, Xinhui; Fan, Jinjin; Chen, Wenfang; Wang, Juan; Zeng, Youjia; Feng, Xiaorang; Yu, Xueqing; Yang, Xiao

    2014-01-01

    Bardoxolone methyl (BARD) is an antioxidant modulator that acts through induction of the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. This study aimed to investigate the role of BARD in protecting kidneys from aristolochic acid (AA)-induced acute kidney injury (AKI). Male C57BL/6 mice received intraperitoneal (i.p.) injections of aristolochic acid I (AAI) (5 mg/kg/day) for 5 days to produce acute AA nephropathy (AAN) model. BARD (10 mg/kg/day, i.p.) was applied for 7 consecutive days, starting 2 days prior to AAI administration. The mice in the AA group showed AKI as evidenced by worsening kidney function evaluated by blood urea nitrogen (BUN) and serum creatinine (SCr) levels, and severe tubulointerstitial injury marked by massive tubule necrosis in kidney tissues. BARD significantly reduced BUN and SCr levels which were elevated by AAI. Additionally, AAI-induced histopathological renal damage was ameliorated by BARD. Furthermore, the expression of Nrf2 was reduced, and its repressor Kelch-like ECH-associated protein 1 (Keap1) was increased significantly, whereas heme oxygenase-1 (HO-1) was upregulated and NAD(P)H quinone oxidoreductase-1 (NQO1) was barely increased in the cytoplasm of tubules in kidneys after treatment with AAI. BARD significantly upregulated renal Nrf2, NQO1 and HO-1 expression and downregulated Keap1 expression compared with those in the AA group. Moreover, it was found that Nrf2 was expressed both in the cytoplasm and nuclear of glomeruli and tubules, whereas NQO1 and HO-1 were localized in the cytoplasm of tubules only. In conclusion, AA-induced acute renal injury was associated with impaired Nrf2 activation and expression of its downstream target genes in renal tissues. BARD prevented renal damage induced by AAI, and this renoprotective effect may be exerted by activating the Nrf2 signaling pathway and increasing expression of the downstream target genes

  7. The chalcone compound isosalipurposide (ISPP) exerts a cytoprotective effect against oxidative injury via Nrf2 activation

    International Nuclear Information System (INIS)

    Han, Jae Yun; Cho, Seung Sik; Yang, Ji Hye; Kim, Kyu Min; Jang, Chang Ho; Park, Da Eon; Bang, Joon Seok; Jung, Young Suk; Ki, Sung Hwan

    2015-01-01

    The chalcone compound isosalipurposide (ISPP) has been successfully isolated from the native Korean plant species Corylopsis coreana Uyeki (Korean winter hazel). However, the therapeutic efficacy of ISPP remains poorly understood. This study investigated whether ISPP has the capacity to activate NF-E2-related factor (Nrf2)-antioxidant response element (ARE) signaling and induce its target gene expression, and to determined the protective role of ISPP against oxidative injury of hepatocytes. In HepG2 cells, nuclear translocation of Nrf2 is augmented by ISPP treatment. Consistently, ISPP increased ARE reporter gene activity and the protein levels of glutamate cysteine ligase (GCL) and hemeoxygenase (HO-1), resulting in increased intracellular glutathione levels. Cells pretreated with ISPP were rescued from tert-butylhydroperoxide-induced reactive oxygen species (ROS) production and glutathione depletion and consequently, apoptotic cell death. Moreover, ISPP ameliorated the mitochondrial dysfunction and apoptosis induced by rotenone which is an inhibitor of complex 1 of the mitochondrial respiratory chain. The specific role of Nrf2 activation by ISPP was demonstrated using an ARE-deletion mutant plasmid and Nrf2-knockout cells. Finally, we observed that extracellular signal-regulated kinase (ERK) and AMP-activated protein kinase (AMPK), but not protein kinase C (PKC)-δ or other mitogen-activated protein kinases (MAPKs), are involved in the activation of Nrf2 by ISPP. Taken together, our results demonstrate that ISPP has a cytoprotective effect against oxidative damage mediated through Nrf2 activation and induction of its target gene expression in hepatocytes. - Highlights: • We investigated the effect of ISPP on Nrf2 activation. • ISPP increased Nrf2 activity and its target gene expression. • ISPP inhibited the mitochondrial dysfunction and ROS production. • Nrf2 activation by ISPP is dependent on ERK1/2 and AMPK phosphorylation. • ISPP may be a promising

  8. The chalcone compound isosalipurposide (ISPP) exerts a cytoprotective effect against oxidative injury via Nrf2 activation

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jae Yun [College of Pharmacy, Chosun University, Gwangju 501-759 (Korea, Republic of); Cho, Seung Sik [College of Pharmacy, Mokpo National University, Muan, Jeonnam 535-729 (Korea, Republic of); Yang, Ji Hye; Kim, Kyu Min; Jang, Chang Ho [College of Pharmacy, Chosun University, Gwangju 501-759 (Korea, Republic of); Park, Da Eon [College of Pharmacy, Mokpo National University, Muan, Jeonnam 535-729 (Korea, Republic of); Bang, Joon Seok [Graduate School of Clinical Pharmacy, Sookmyung Women' s University, Seoul (Korea, Republic of); Jung, Young Suk [College of Pharmacy, Pusan National University, Busan (Korea, Republic of); Ki, Sung Hwan, E-mail: shki@chosun.ac.kr [College of Pharmacy, Chosun University, Gwangju 501-759 (Korea, Republic of)

    2015-08-15

    The chalcone compound isosalipurposide (ISPP) has been successfully isolated from the native Korean plant species Corylopsis coreana Uyeki (Korean winter hazel). However, the therapeutic efficacy of ISPP remains poorly understood. This study investigated whether ISPP has the capacity to activate NF-E2-related factor (Nrf2)-antioxidant response element (ARE) signaling and induce its target gene expression, and to determined the protective role of ISPP against oxidative injury of hepatocytes. In HepG2 cells, nuclear translocation of Nrf2 is augmented by ISPP treatment. Consistently, ISPP increased ARE reporter gene activity and the protein levels of glutamate cysteine ligase (GCL) and hemeoxygenase (HO-1), resulting in increased intracellular glutathione levels. Cells pretreated with ISPP were rescued from tert-butylhydroperoxide-induced reactive oxygen species (ROS) production and glutathione depletion and consequently, apoptotic cell death. Moreover, ISPP ameliorated the mitochondrial dysfunction and apoptosis induced by rotenone which is an inhibitor of complex 1 of the mitochondrial respiratory chain. The specific role of Nrf2 activation by ISPP was demonstrated using an ARE-deletion mutant plasmid and Nrf2-knockout cells. Finally, we observed that extracellular signal-regulated kinase (ERK) and AMP-activated protein kinase (AMPK), but not protein kinase C (PKC)-δ or other mitogen-activated protein kinases (MAPKs), are involved in the activation of Nrf2 by ISPP. Taken together, our results demonstrate that ISPP has a cytoprotective effect against oxidative damage mediated through Nrf2 activation and induction of its target gene expression in hepatocytes. - Highlights: • We investigated the effect of ISPP on Nrf2 activation. • ISPP increased Nrf2 activity and its target gene expression. • ISPP inhibited the mitochondrial dysfunction and ROS production. • Nrf2 activation by ISPP is dependent on ERK1/2 and AMPK phosphorylation. • ISPP may be a promising

  9. Characterization of docosahexaenoic acid (DHA)-induced heme oxygenase-1 (HO-1) expression in human cancer cells: the importance of enhanced BTB and CNC homology 1 (Bach1) degradation.

    Science.gov (United States)

    Wang, Shuai; Hannafon, Bethany N; Wolf, Roman F; Zhou, Jundong; Avery, Jori E; Wu, Jinchang; Lind, Stuart E; Ding, Wei-Qun

    2014-05-01

    The effect of docosahexaenoic acid (DHA) on heme oxygenase-1 (HO-1) expression in cancer cells has never been characterized. This study examines DHA-induced HO-1 expression in human cancer cell model systems. DHA enhanced HO-1 gene expression in a time- and concentration-dependent manner, with maximal induction at 21 h of treatment. This induction of HO-1 expression was confirmed in vivo using a xenograft nude mouse model fed a fish-oil-enriched diet. The increase in HO-1 gene transcription induced by DHA was significantly attenuated by the antioxidant N-acetyl cysteine, suggesting the involvement of oxidative stress. This was supported by direct measurement of lipid peroxide levels after DHA treatment. Using a human HO-1 gene promoter reporter construct, we identified two antioxidant response elements (AREs) that mediate the DHA-induced increase in HO-1 gene transcription. Knockdown of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression compromised the DHA-induced increase in HO-1 gene transcription, indicating the importance of the Nrf2 pathway in this event. However, the nuclear protein levels of Nrf2 remained unchanged upon DHA treatment. Further studies demonstrated that DHA reduces nuclear Bach1 protein expression by promoting its degradation and attenuates Bach1 binding to the AREs in the HO-1 gene promoter. In contrast, DHA enhanced Nrf2 binding to the AREs without affecting nuclear Nrf2 expression levels, indicating a new cellular mechanism that mediates DHA's induction of HO-1 gene transcription. To our knowledge, this is the first characterization of DHA-induced HO-1 expression in human malignant cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Activation of Nrf2 attenuates carbonyl stress induced by methylglyoxal in human neuroblastoma cells: Increase in GSH levels is a critical event for the detoxification mechanism.

    Science.gov (United States)

    Nishimoto, Shoichi; Koike, Shin; Inoue, Naho; Suzuki, Toshihiro; Ogasawara, Yuki

    2017-02-05

    The present study focused on the methylglyoxal (MG) detoxification mechanism in neuroblastoma cells. The involvement of nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1) pathway as a defense response against the formation of MG-modified proteins, which is well-known evidence of carbonyl stress, was also examined. We found that MG treatment resulted in accumulation of modified proteins bearing the structure of advanced glycation end products (AGEs) derived from MG in SH-SY5Y cells. This accumulation was suppressed by activation of the Nrf2 pathway prior to MG exposure via pre-treatment with an Nrf2 activator, carnosic acid and CDDO-Im, confirming the involvement of the Nrf2 pathway in MG detoxification. Although pre-treatment with the Nrf2 activator did not affect mRNA levels of GLO1, AKR1B1, and AKR7A2, the expressions of GCL and xCT mRNA, involved in GSH synthesis, were induced prior to increase in GSH levels. Furthermore, we demonstrated that a GSH synthesis inhibitor eliminated the MG detoxification effect derived from pretreatment with the Nrf2 activator. These results indicated that increase in GSH levels, induced by pre-treatment with carnosic acid, promoted the formation of the GLO1 substrate, hemithioacetal, thereby accelerating MG metabolism via the glyoxalase system and suppressing its toxicity. It was, therefore, determined that promotion of GSH synthesis via the Nrf2/Keap1pathway is important in the MG detoxification mechanism against neuronal MG-induced carbonyl stress, and Nrf2 activators contribute to reduction in the accumulation and toxic expression of carbonyl proteins. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Adiponectin ameliorates hyperglycemia-induced cardiac hypertrophy and dysfunction by concomitantly activating Nrf2 and Brg1.

    Science.gov (United States)

    Li, Haobo; Yao, Weifeng; Irwin, Michael G; Wang, Tingting; Wang, Shuang; Zhang, Liangqing; Xia, Zhengyuan

    2015-07-01

    Hyperglycemia-induced oxidative stress is implicated in the development of cardiomyopathy in diabetes that is associated with reduced adiponectin (APN) and heme oxygenase-1 (HO-1). Brahma-related gene 1 (Brg1) assists nuclear factor-erythroid-2-related factor-2 (Nrf2) to activate HO-1 to increase myocardial antioxidant capacity in response to oxidative stress. We hypothesized that reduced adiponectin (APN) impairs HO-1 induction which contributes to the development of diabetic cardiomyopathy, and that supplementation of APN may ameliorate diabetic cardiomyopathy by activating HO-1 through Nrf2 and Brg1 in diabetes. Control (C) and streptozotocin-induced diabetic (D) rats were untreated or treated with APN adenovirus (1×10(9) pfu) 3 weeks after diabetes induction and examined and terminated 1 week afterward. Rat left ventricular functions were assessed by a pressure-volume conductance system, before the rat hearts were removed to perform histological and biochemical assays. Four weeks after diabetes induction, D rats developed cardiac hypertrophy evidenced as increased ratio of heart weight to body weight, elevated myocardial collagen I content, and larger cardiomyocyte cross-sectional area (all Psupplementation of recombined globular APN (gAd, 2μg/mL) reversed HG-induced reductions of HO-1, Brg1, and nuclear Nrf2 protein expression and attenuated cellular oxidative stress, myocyte size, and apoptotic cells. Inhibition of HO-1 by ZnPP (10μM) or small interfering RNA (siRNA) canceled all the above gAd beneficial effects. Moreover, inhibition of Nrf2 (either by the Nrf2 inhibitor luteolin or siRNA) or Brg1 (by siRNA) canceled gAd-induced HO-1 induction and cellular protection in CMs and in H9C2 cells incubated with HG. In summary, our present study demonstrated that APN reduced cardiac oxidative stress, ameliorated cardiomyocyte hypertrophy, and prevented left ventricular dysfunction in diabetes by concomitantly activating Nrf2 and Brg1 to facilitate HO-1 induction

  12. Metformin inhibits heme oxygenase-1 expression in cancer cells through inactivation of Raf-ERK-Nrf2 signaling and AMPK-independent pathways

    International Nuclear Information System (INIS)

    Do, Minh Truong; Kim, Hyung Gyun; Khanal, Tilak; Choi, Jae Ho; Kim, Dong Hee; Jeong, Tae Cheon; Jeong, Hye Gwang

    2013-01-01

    Resistance to therapy is the major obstacle to more effective cancer treatment. Heme oxygenase-1 (HO-1) is often highly up-regulated in tumor tissues, and its expression is further increased in response to therapies. It has been suggested that inhibition of HO-1 expression is a potential therapeutic approach to sensitize tumors to chemotherapy and radiotherapy. In this study, we tested the hypothesis that the anti-tumor effects of metformin are mediated by suppression of HO-1 expression in cancer cells. Our results indicate that metformin strongly suppresses HO-1 mRNA and protein expression in human hepatic carcinoma HepG2, cervical cancer HeLa, and non-small-cell lung cancer A549 cells. Metformin also markedly reduced Nrf2 mRNA and protein levels in whole cell lysates and suppressed tert-butylhydroquinone (tBHQ)-induced Nrf2 protein stability and antioxidant response element (ARE)-luciferase activity in HepG2 cells. We also found that metformin regulation of Nrf2 expression is mediated by a Keap1-independent mechanism and that metformin significantly attenuated Raf-ERK signaling to suppress Nrf2 expression in cancer cells. Inhibition of Raf-ERK signaling by PD98059 decreased Nrf2 mRNA expression in HepG2 cells, confirming that the inhibition of Nrf2 expression is mediated by an attenuation of Raf-ERK signaling in cancer cells. The inactivation of AMPK by siRNA, DN-AMPK or the pharmacological AMPK inhibitor compound C, revealed that metformin reduced HO-1 expression in an AMPK-independent manner. These results highlight the Raf-ERK-Nrf2 axis as a new molecular target in anticancer therapy in response to metformin treatment. - Highlights: • Metformin inhibits HO-1 expression in cancer cells. • Metformin attenuates Raf-ERK-Nrf2 signaling. • Suppression of HO-1 by metformin is independent of AMPK. • HO-1 inhibition contributes to anti-proliferative effects of metformin

  13. Isorhamnetin protects against oxidative stress by activating Nrf2 and inducing the expression of its target genes

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ji Hye; Shin, Bo Yeon; Han, Jae Yun; Kim, Mi Gwang; Wi, Ji Eun [College of Pharmacy, Chosun University, Gwangju, 501-759 (Korea, Republic of); Kim, Young Woo; Cho, Il Je; Kim, Sang Chan [Medical Research Center for Globalization of Herbal Formulation, College of Korean Medicine, Daegu Haany University, Gyeongsan 712-715 (Korea, Republic of); Shin, Sang Mi [College of Pharmacy, Chosun University, Gwangju, 501-759 (Korea, Republic of); Ki, Sung Hwan, E-mail: shki@chosun.ac.kr [College of Pharmacy, Chosun University, Gwangju, 501-759 (Korea, Republic of)

    2014-01-15

    Isorhamentin is a 3′-O-methylated metabolite of quercetin, and has been reported to have anti-inflammatory and anti-proliferative effects. However, the effects of isorhamnetin on Nrf2 activation and on the expressions of its downstream genes in hepatocytes have not been elucidated. Here, we investigated whether isorhamnetin has the ability to activate Nrf2 and induce phase II antioxidant enzyme expression, and to determine the protective role of isorhamnetin on oxidative injury in hepatocytes. In HepG2 cells, isorhamnetin increased the nuclear translocation of Nrf2 in a dose- and time-dependent manner, and consistently, increased antioxidant response element (ARE) reporter gene activity and the protein levels of hemeoxygenase (HO-1) and of glutamate cysteine ligase (GCL), which resulted in intracellular GSH level increases. The specific role of Nrf2 in isorhamnetin-induced Nrf2 target gene expression was verified using an ARE-deletion mutant plasmid and Nrf2-knockout MEF cells. Deletion of the ARE in the promoter region of the sestrin2 gene, which is recently identified as the Nrf2 target gene by us, abolished the ability of isorhamnetin to increase luciferase activity. In addition, Nrf2 deficiency completely blocked the ability of isorhamnetin to induce HO-1 and GCL. Furthermore, isorhamnetin pretreatment blocked t-BHP-induced ROS production and reversed GSH depletion by t-BHP and consequently, due to reduced ROS levels, decreased t-BHP-induced cell death. In addition isorhamnetin increased ERK1/2, PKCδ and AMPK phosphorylation. Finally, we showed that Nrf2 deficiency blocked the ability of isorhamnetin to protect cells from injury induced by t-BHP. Taken together, our results demonstrate that isorhamnetin is efficacious in protecting hepatocytes against oxidative stress by Nrf2 activation and in inducing the expressions of its downstream genes. - Highlights: • We investigated the effect of isorhamnetin on Nrf2 activation. • Isorhamnetin increased Nrf2

  14. Nrf2-inducing anti-oxidation stress response in the rat liver--new beneficial effect of lansoprazole.

    Science.gov (United States)

    Yamashita, Yasunobu; Ueyama, Takashi; Nishi, Toshio; Yamamoto, Yuta; Kawakoshi, Akatsuki; Sunami, Shogo; Iguchi, Mikitaka; Tamai, Hideyuki; Ueda, Kazuki; Ito, Takao; Tsuruo, Yoshihiro; Ichinose, Masao

    2014-01-01

    Lansoprazole is a potent anti-gastric ulcer drug that inhibits gastric proton pump activity. We identified a novel function for lansoprazole, as an inducer of anti-oxidative stress responses in the liver. Gastric administration of lansoprazole (10-100 mg/kg) to male Wistar rats produced a dose-dependent increase in hepatic mRNA levels of nuclear factor, erythroid-derived 2, -like 2 (Nrf2), a redox-sensitive transcription factor, at 3 h and Nrf2 immunoreactivity (IR) in whole hepatic lysates at 6 h. Conversely, the levels of Kelch-like ECH-associated protein (Keap1), which sequesters Nrf2 in the cytoplasm under un-stimulated conditions, were unchanged. Translocation of Nrf2 into the nuclei of hepatocytes was observed using western blotting and immunohistochemistry. Expression of mRNAs for Nrf2-dependent antioxidant and phase II enzymes, such as heme oxygenase 1 (HO-1), NAD (P) H dehydrogenase, quinone 1 (Nqo1), glutathione S-transferase A2 (Gsta2), UDP glucuronosyltransferase 1 family polypeptide A6 (Ugt1a6), were dose-dependently up-regulated at 3 h. Furthermore, the levels of HO-1 IR were dose-dependently increased in hepatocytes at 6 h. Subcutaneous administration of lansoprazole (30 mg/kg/day) for 7 successive days resulted in up-regulation and nuclear translocation of Nrf2 IR in hepatocytes and up-regulation of HO-1 IR in the liver. Pretreatment with lansoprazole attenuated thioacetamide (500 mg/kg)-induced acute hepatic damage via both HO-1-dependent and -independent pathways. Up-stream networks related to Nrf2 expression were investigated using microarray analysis, followed by data mining with Ingenuity Pathway Analysis. Up-regulation of the aryl hydrocarbon receptor (AhR)-cytochrome P450, family 1, subfamily a, polypeptide 1 (Cyp1a1) pathway was associated with up-regulation of Nrf2 mRNA. In conclusion, lansoprazole might have an alternative indication in the prevention and treatment of oxidative hepatic damage through the induction of both phase I and phase

  15. Nrf2-Inducing Anti-Oxidation Stress Response in the Rat Liver - New Beneficial Effect of Lansoprazole

    Science.gov (United States)

    Yamashita, Yasunobu; Ueyama, Takashi; Nishi, Toshio; Yamamoto, Yuta; Kawakoshi, Akatsuki; Sunami, Shogo; Iguchi, Mikitaka; Tamai, Hideyuki; Ueda, Kazuki; Ito, Takao; Tsuruo, Yoshihiro; Ichinose, Masao

    2014-01-01

    Lansoprazole is a potent anti-gastric ulcer drug that inhibits gastric proton pump activity. We identified a novel function for lansoprazole, as an inducer of anti-oxidative stress responses in the liver. Gastric administration of lansoprazole (10–100 mg/kg) to male Wistar rats produced a dose-dependent increase in hepatic mRNA levels of nuclear factor, erythroid-derived 2, -like 2 (Nrf2), a redox-sensitive transcription factor, at 3 h and Nrf2 immunoreactivity (IR) in whole hepatic lysates at 6 h. Conversely, the levels of Kelch-like ECH-associated protein (Keap1), which sequesters Nrf2 in the cytoplasm under un-stimulated conditions, were unchanged. Translocation of Nrf2 into the nuclei of hepatocytes was observed using western blotting and immunohistochemistry. Expression of mRNAs for Nrf2-dependent antioxidant and phase II enzymes, such as heme oxygenase 1 (HO-1), NAD (P) H dehydrogenase, quinone 1 (Nqo1), glutathione S-transferase A2 (Gsta2), UDP glucuronosyltransferase 1 family polypeptide A6 (Ugt1a6), were dose-dependently up-regulated at 3 h. Furthermore, the levels of HO-1 IR were dose-dependently increased in hepatocytes at 6 h. Subcutaneous administration of lansoprazole (30 mg/kg/day) for 7 successive days resulted in up-regulation and nuclear translocation of Nrf2 IR in hepatocytes and up-regulation of HO-1 IR in the liver. Pretreatment with lansoprazole attenuated thioacetamide (500 mg/kg)-induced acute hepatic damage via both HO-1-dependent and -independent pathways. Up-stream networks related to Nrf2 expression were investigated using microarray analysis, followed by data mining with Ingenuity Pathway Analysis. Up-regulation of the aryl hydrocarbon receptor (AhR)-cytochrome P450, family 1, subfamily a, polypeptide 1 (Cyp1a1) pathway was associated with up-regulation of Nrf2 mRNA. In conclusion, lansoprazole might have an alternative indication in the prevention and treatment of oxidative hepatic damage through the induction of both phase I and

  16. Phytochemicals and botanical extracts regulate NF-κB and Nrf2/ARE reporter activities in DI TNC1 astrocytes.

    Science.gov (United States)

    Ajit, Deepa; Simonyi, Agnes; Li, Runting; Chen, Zihong; Hannink, Mark; Fritsche, Kevin L; Mossine, Valeri V; Smith, Robert E; Dobbs, Thomas K; Luo, Rensheng; Folk, William R; Gu, Zezong; Lubahn, Dennis B; Weisman, Gary A; Sun, Grace Y

    2016-07-01

    The increase in oxidative stress and inflammatory responses associated with neurodegenerative diseases has drawn considerable attention towards understanding the transcriptional signaling pathways involving NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) and Nrf2 (Nuclear Factor Erythroid 2-like 2). Our recent studies with immortalized murine microglial cells (BV-2) demonstrated effects of botanical polyphenols to inhibit lipopolysaccharide (LPS)-induced nitric oxide (NO) and enhance Nrf2-mediated antioxidant responses (Sun et al., 2015). In this study, an immortalized rat astrocyte (DI TNC1) cell line expressing a luciferase reporter driven by the NF-κB or the Nrf2/Antioxidant Response Element (ARE) promoter was used to assess regulation of these two pathways by phytochemicals such as quercetin, rutin, cyanidin, cyanidin-3-O-glucoside, as well as botanical extracts from Withania somnifera (Ashwagandha), Sutherlandia frutescens (Sutherlandia) and Euterpe oleracea (Açaí). Quercetin effectively inhibited LPS-induced NF-κB reporter activity and stimulated Nrf2/ARE reporter activity in DI TNC1 astrocytes. Cyanidin and the glycosides showed similar effects but only at much higher concentrations. All three botanical extracts effectively inhibited LPS-induced NF-κB reporter activity. These extracts were capable of enhancing ARE activity by themselves and further enhanced ARE activity in the presence of LPS. Quercetin and botanical extracts induced Nrf2 and HO-1 protein expression. Interestingly, Ashwagandha extract was more active in inducing Nrf2 and HO-1 expression in DI TNC1 astrocytes as compared to Sutherlandia and Açaí extracts. In summary, this study demonstrated NF-kB and Nrf2/ARE promoter activities in DI TNC1 astrocytes, and further showed differences in ability for specific botanical polyphenols and extracts to down-regulate LPS-induced NF-kB and up-regulate the NRF2/ARE activities in these cells. Copyright © 2016 Elsevier Ltd

  17. Non-coding RNA derived from the region adjacent to the human HO-1 E2 enhancer selectively regulates HO-1 gene induction by modulating Pol II binding.

    Science.gov (United States)

    Maruyama, Atsushi; Mimura, Junsei; Itoh, Ken

    2014-12-16

    Recent studies have disclosed the function of enhancer RNAs (eRNAs), which are long non-coding RNAs transcribed from gene enhancer regions, in transcriptional regulation. However, it remains unclear whether eRNAs are involved in the regulation of human heme oxygenase-1 gene (HO-1) induction. Here, we report that multiple nuclear-enriched eRNAs are transcribed from the regions adjacent to two human HO-1 enhancers (i.e. the distal E2 and proximal E1 enhancers), and some of these eRNAs are induced by the oxidative stress-causing reagent diethyl maleate (DEM). We demonstrated that the expression of one forward direction (5' to 3') eRNA transcribed from the human HO-1 E2 enhancer region (named human HO-1enhancer RNA E2-3; hereafter called eRNA E2-3) was induced by DEM in an NRF2-dependent manner in HeLa cells. Conversely, knockdown of BACH1, a repressor of HO-1 transcription, further increased DEM-inducible eRNA E2-3 transcription as well as HO-1 expression. In addition, we showed that knockdown of eRNA E2-3 selectively down-regulated DEM-induced HO-1 expression. Furthermore, eRNA E2-3 knockdown attenuated DEM-induced Pol II binding to the promoter and E2 enhancer regions of HO-1 without affecting NRF2 recruitment to the E2 enhancer. These findings indicate that eRNAE2-3 is functional and is required for HO-1 induction. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  18. Berberine, a natural antidiabetes drug, attenuates glucose neurotoxicity and promotes Nrf2-related neurite outgrowth

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Ya-Yun [Department of Pharmacology, School of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Tseng, Yu-Ting [Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Lo, Yi-Ching, E-mail: yichlo@kmu.edu.tw [Department of Pharmacology, School of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China)

    2013-11-01

    Reactive oxygen intermediates production and apoptotic damage induced by high glucose are major causes of neuronal damage in diabetic neuropathy. Berberine (BBR), a natural antidiabetes drug with PI3K-activating activity, holds promise for diabetes because of its dual antioxidant and anti-apoptotic activities. We have previously reported that BBR attenuated H{sub 2}O{sub 2} neurotoxicity via activating the PI3K/Akt/Nrf2-dependent pathway. In this study, we further explored the novel protective mechanism of BBR on high glucose-induced apoptotic death and neurite damage of SH-SY5Y cells. Results indicated BBR (0.1–10 nM) significantly attenuated reactive oxygen species (ROS) production, nucleus condensation, and apoptotic death in high glucose-treated cells. However, AG1024, an inhibitor of insulin growth factor-1 (IGF-1) receptor, significantly abolished BBR protection against high glucose-induced neuronal death. BBR also increased Bcl-2 expression and decreased cytochrome c release. High glucose down-regulated IGF-1 receptor and phosphorylation of Akt and GSK-3β, the effects of which were attenuated by BBR treatment. BBR also activated nuclear erythroid 2-related factor 2 (Nrf2), the key antioxidative transcription factor, which is accompanied with up-regulation of hemeoxygenase-1 (HO-1). Furthermore, BBR markedly enhanced nerve growth factor (NGF) expression and promoted neurite outgrowth in high glucose-treated cells. To further determine the role of the Nrf2 in BBR neuroprotection, RNA interference directed against Nrf2 was used. Results indicated Nrf2 siRNA abolished BBR-induced HO-1, NGF, neurite outgrowth and ROS decrease. In conclusion, BBR attenuated high glucose-induced neurotoxicity, and we are the first to reveal this novel mechanism of BBR as an Nrf2 activator against glucose neurotoxicity, providing another potential therapeutic use of BBR on the treatment of diabetic complications. - Highlights: • BBR attenuates high glucose-induced ROS

  19. Epigenetic modification of Nrf2 by sulforaphane increases the antioxidative and anti-inflammatory capacity in a cellular model of Alzheimer's disease.

    Science.gov (United States)

    Zhao, Fangfang; Zhang, Jianlei; Chang, Na

    2018-04-05

    Sulforaphane was reported to exert neuroprotective effects via upregulating expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and has received increasing attention as an alternative candidate for treatment of Alzheimer's disease (AD). However, the mechanism to account for Nrf2 upregulation by sulforaphane in AD remains unknown. Herein, we found that sulforaphane upregulated Nrf2 expression and promoted Nrf2 nuclear translocation via decreasing DNA methylation levels of the Nrf2 promoter in mouse neuroblastoma N2a cells stably expressing human Swedish mutant amyloid precursor protein (N2a/APPswe cells), a cellular model of AD. Furthermore, sulforaphane (1.25 and 2.5 μM) decreased the levels of amyloid β 1-40 (Aβ 1-40 ) (21.7% and 33.4% decrease for intracellular Aβ 1-40 ; 22.0% and 30.2% decrease in culture medium), Aβ 1-42 (26.4% and 42.9% decrease for intracellular Aβ 1-42 ; 25.8% and 43.8% decrease in culture medium), reactive oxygen species (15.0% and 28.5% decrease), and malondialdehyde (MDA) (34.4% and 39.2% decrease) and increased superoxide dismutase (SOD) (60.0% and 89.3% increase) activity in N2a/APPswe cells. Sulforaphane also decreased the levels of pro-inflammatory cytokines interleukin 1β (IL-1β) (16.5% and 33.6% decrease) and IL-6 (15.6% and 26.1% decrease) and reduced phosphorylated nuclear factor-κB (NF-κB) p65 (19.2% and 32.2% decrease), cyclooxygenase-2 (COX-2) (20.5% and 28.6% decrease), and iNOS protein (40.2% and 54.7% decrease) expression levels in N2a/APPswe cells. Our study suggested that sulforaphane upregulated the expression of Nrf2 and promoted the nuclear translocation of Nrf2 by decreasing DNA demethylation levels of the Nrf2 promoter, thus leading to antioxidative and anti-inflammatory effects in a cellular model of AD. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Reduced Nrf2 activation in PI3K phosphorylation-impaired vitiliginous keratinocytes increases susceptibility to ROS-generating chemical-induced apoptosis.

    Science.gov (United States)

    Kim, Hyangmi; Park, Chang Seo; Lee, Ai-Young

    2017-12-01

    Keratinocytes in affected epidermis of vitiligo patients are known to have impaired activation of the PI3K/AKT pathway. Based on critical roles of keratinocytes and oxidative stress in vitiligo development, this study examined whether keratinocytes with impaired PI3K activation were more vulnerable to apoptosis caused by oxidative stress from phenolic compounds, p-tert-butylphenol (4-TBP) and hydroquinone (HQ). Cell viability assay, FACS analysis, ELISA for TNF-α or IL-1a, ROS assay, Western blot analysis for Nrf2 expression, and confocal microscopy with anti-Nrf2 and phospho-PI3K antibodies were done on primary cultured normal human keratinocytes with or without PI3K knockdown in the presence or absence of chemical treatment or antioxidant. Immunofluorescence staining using anti-Nrf2, phospho-PI3K, TNF-ɑ, and IL-1ɑ antibodies, ROS assay using dihydroethidium, and TUNEL assay were performed on sets of depigmented and normally pigmented skin from vitiligo patients. Results showed that 4-TBP or HQ treatment increased apoptosis and the expression levels of TNF-ɑ, IL-1ɑ, and ROS in PI3K-knockdown keratinocytes which reduced Nrf2 nuclear translocation compared to control keratinocytes. These changes were significantly recovered by an antioxidant treatment. Depigmented epidermis of vitiligo patients also showed lower levels of Nrf2 and phospho-PI3K but higher levels of ROS, TNF-ɑ, IL-1ɑ, and ROS with more TUNEL-positive cells. Therefore, impaired PI3K activation in keratinocytes in depigmented epidermis of vitiligo patients are vulnerable to apoptosis caused by ROS-generating chemicals due to reduced Nrf2 activation. © 2017 Wiley Periodicals, Inc.

  1. Decursin Isolated from Angelica gigas Nakai Rescues PC12 Cells from Amyloid β-Protein-Induced Neurotoxicity through Nrf2-Mediated Upregulation of Heme Oxygenase-1: Potential Roles of MAPK

    Directory of Open Access Journals (Sweden)

    Li Li

    2013-01-01

    Full Text Available Decursin (D, purified from Angelica gigas Nakai, has been proven to exert neuroprotective property. Previous study revealed that D reduced Aβ25‒35-induced cytotoxicity in PC12 cells. Our study explored the underlying mechanisms by which D mediates its therapeutic effects in vitro. Pretreatment of cells with D diminished intracellular generation of ROS in response to Aβ25‒35. Western blot revealed that D significantly increased the expression and activity of HO-1, which was correlated with its protection against Aβ25‒35-induced injury. Addition of ZnPP, an HO-1 competitive inhibitor, significantly attenuated its protective effect in Aβ25‒35-treated cells, indicating the vital role of HO-1 resistance to oxidative injury. Moreover, D induced Nrf2 nuclear translocation, the upstream of HO-1 expression. While investigating the signaling pathways responsible for HO-1 induction, D activated ERK and dephosphorylated p38 in PC12 cells. Addition of U0126, a selective inhibitor of ERK, blocked D-induced Nrf2 activation and HO-1 induction and meanwhile reversed the protection of D against Aβ25‒35-induced cell death. These findings suggest D augments cellular antioxidant defense capacity through both intrinsic free radical scavenging activity and activation of MAPK signal pathways that leads to Nrf2 activation, and subsequently HO-1 induction, thereby protecting the PC12 cells from Aβ25‒35-induced oxidative cytotoxicity.

  2. Lansoprazole halts contrast induced nephropathy through activation of Nrf2 pathway in rats.

    Science.gov (United States)

    Khaleel, Sahar A; Alzokaky, Amany A; Raslan, Nahed A; Alwakeel, Asmaa I; Abd El-Aziz, Heba G; Abd-Allah, Adel R

    2017-05-25

    Contrast-induced nephropathy (CIN) is an important cause of acute kidney injury characterized by significant mortality and morbidity. To date, there is no successful protective regimen for CIN especially in poor kidney function patients. Lansoprazole has been shown to exert antioxidant action through induction of nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway. The aim of the present study is to investigate the potential of lansoprazole to activate Nrf2 pathway in the kidney and consequently to protect against oxidative stress induced by iodinated contrast media. Lansoprazole, at a dose of 100 mg/kg, showed a significant induction of Nrf2 mRNA after 3 h. Administration of contrast media induced significant increase in serum creatinine and blood urea nitrogen, histological deterioration, and reduction in total antioxidant capacity. Moreover, it instigated the defensive Nrf2 gene expression and immunoreactivity. In addition, there were overexpression of HO-1, caspase 3, p53 and IL6 genes and downregulation of Bcl2 gene. Pre-treatment with lansoprazole (100 mg/kg) ameliorated the nephrotoxicity parameters and oxidative stress, improved histological lesions, and hijacked apoptotic and inflammatory markers that were provoked by contrast media. In conclusion, lansoprazole attenuates experimental CIN which might be due to activation of Nrf2 antioxidant defence pathway. These findings highlight the potential benefit of incorporating lansoprazole in the protective regimen against CIN especially for susceptible patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Chronic Endurance Exercise Impairs Cardiac Structure and Function in Middle-Aged Mice with Impaired Nrf2 Signaling

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    Gobinath Shanmugam

    2017-05-01

    Full Text Available Nuclear factor erythroid 2 related factor 2 (Nrf2 signaling maintains the redox homeostasis and its activation is shown to suppress cardiac maladaptation. Earlier we reported that acute endurance exercise (2 days evoked antioxidant cytoprotection in young WT animals but not in aged WT animals. However, the effect of repeated endurance exercise during biologic aging (WT characterized by an inherent deterioration in Nrf2 signaling and pathological aging (pronounced oxidative susceptibility—Nrf2 absence in the myocardium remains elusive. Thus, the purpose of our study was to determine the effect of chronic endurance exercise-induced cardiac adaptation in aged mice with and without Nrf2. Age-matched WT and Nrf2-null mice (Nrf2−/− (>22 months were subjected to 6 weeks chronic endurance exercise (25 meter/min, 12% grade. The myocardial redox status was assessed by expression of antioxidant defense genes and proteins along with immunochemical detection of DMPO-radical adduct, GSH-NEM, and total ubiquitination. Cardiac functions were assessed by echocardiography and electrocardiogram. At sedentary state, loss of Nrf2 resulted in significant downregulation of antioxidant gene expression (Nqo1, Ho1, Gclm, Cat, and Gst-α with decreased GSH-NEM immuno-fluorescence signals. While Nrf2−/− mice subjected to CEE showed an either similar or more pronounced reduction in the transcript levels of Gclc, Nqo1, Gsr, and Gst-α in relation to WT littermates. In addition, the hearts of Nrf2−/− on CEE showed a substantial reduction in specific antioxidant proteins, G6PD and CAT along with decreased GSH, a pronounced increase in DMPO-adduct and the total ubiquitination levels. Further, CEE resulted in a significant upregulation of hypertrophy genes (Anf, Bnf, and β-Mhc (p < 0.05 in the Nrf2−/− hearts in relation to WT mice. Moreover, the aged Nrf2−/− mice exhibited a higher degree of cardiac remodeling in association with a significant decrease in

  4. Nrf2 protects against 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced oxidative injury and steatohepatitis

    International Nuclear Information System (INIS)

    Lu Hong; Cui Wei; Klaassen, Curtis D.

    2011-01-01

    Previous studies demonstrate that Nrf2, a master regulator of antioxidative responses, is essential in mediating induction of many antioxidative enzymes by acute activation of the AhR. However, the role of Nrf2 in protecting against oxidative stress and DNA damage induced by sustained activation of the AhR remains unknown and was investigated herein. Tissue and blood samples were collected from wild-type (WT) and Nrf2-null mice 21 days after administration of a low-toxic dose (10 μg/kg ip) of TCDD. Only Nrf2-null mice lost body weight after TCDD treatment; however, blood levels of ALT were not markedly changed in either genotype, indicating a lack of extensive necrosis. Compared to livers of TCDD-treated WT mice, livers of TCDD-treated Nrf2-null mice had: 1) degenerated hepatocytes, lobular inflammation, marked fat accumulation, and higher mRNA expression of inflammatory and fibrotic genes; 2) depletion of glutathione, elevation in lipid peroxidation and marker of DNA damage; 3) attenuated induction of phase-II enzymes Nqo1, Gsta1/2, and Ugt2b35 mRNAs, but higher induction of cytoprotective Ho-1, Prdx1, Trxr1, Gclc, and Epxh1 mRNAs; 4) higher mRNA expression of Fgf21 and triglyceride-synthesis genes, but down-regulation of bile-acid-synthesis genes and cholesterol-efflux transporters; and 5) trend of induction/activation of c-jun and NF-kB. Additionally, TCDD-treated Nrf2-null mice had impaired adipogenesis in white adipose tissue. In conclusion, Nrf2 protects livers of mice against oxidative stress, DNA damage, and steatohepatitis induced by TCDD-mediated sustained activation of the AhR. The aggravated hepatosteatosis in TCDD-treated Nrf2-null mice is due to increased lipogenesis in liver and impaired lipogenesis in white adipose tissue. - Highlights: → TCDD causes hepatosteatosis and induction of Nrf2-target genes in wild-type mice. → TCDD causes weight loss, oxidative injury, and steatohepatitis in Nrf2-null mice. → Livers of TCDD-treated Nrf2-null mice

  5. NRF2 Protection against Liver Injury Produced by Various Hepatotoxicants

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    Jie Liu

    2013-01-01

    Full Text Available To investigate the role of Nrf2 as a master defense against the hepatotoxicity produced by various chemicals, Nrf2-null, wild-type, Keap1-knock down (Keap1-Kd and Keap1-hepatocyte knockout (Keap1-HKO mice were used as a “graded Nrf2 activation” model. Mice were treated with 14 hepatotoxicants at appropriate doses, and blood and liver samples were collected thereafter (6 h to 7 days depending on the hepatotoxicant. Graded activation of Nrf2 offered a Nrf2-dependent protection against the hepatotoxicity produced by carbon tetrachloride, acetaminophen, microcystin, phalloidin, furosemide, cadmium, and lithocholic acid, as evidenced by serum alanine aminotransferase (ALT activities and by histopathology. Nrf2 activation also offered moderate protection against liver injury produced by ethanol, arsenic, bromobenzene, and allyl alcohol but had no effects on the hepatotoxicity produced by D-galactosamine/endotoxin and the Fas ligand antibody Jo-2. Graded Nrf2 activation reduced the expression of inflammatory genes (MIP-2, mKC, IL-1β, IL-6, and TNFα, oxidative stress genes (Ho-1, Egr1, ER stress genes (Gadd45 and Gadd153, and genes encoding cell death (Noxa, Bax, Bad, and caspase3. Thus, this study demonstrates that Nrf2 prevents the liver from many, but not all, hepatotoxicants. The Nrf2-mediated protection is accompanied by induction of antioxidant genes, suppression of inflammatory responses, and attenuation of oxidative stress.

  6. Inorganic Arsenic Induces NRF2-Regulated Antioxidant Defenses in Both Cerebral Cortex and Hippocampus in Vivo.

    Science.gov (United States)

    Zhang, Yang; Duan, Xiaoxu; Li, Jinlong; Zhao, Shuo; Li, Wei; Zhao, Lu; Li, Wei; Nie, Huifang; Sun, Guifang; Li, Bing

    2016-08-01

    Inorganic arsenic is reported to induce the reactive oxygen species-mediated oxidative stress, which is supposed to be one of the main mechanisms of arsenic-related neurological diseases. Nuclear factor erythroid 2-related factor 2 (NRF2), a master regulator of antioxidant defense systems, up-regulates the expression of target genes to fight against oxidative damages caused by harmful substances, including metals. In the present study, mice were used as a model to investigate the oxidative stress levels and the expressions of NRF2-regulated antioxidant substances in both cerebral cortex and hippocampus with 5, 10 and 20 mg/kg NaAsO2 exposure intra-gastrically. Our results showed that acute NaAsO2 treatment resulted in decreased total anti-oxidative capacity (T-AOC) and increased maleic dialdehyde production in the nervous system. We also detected rapidly elevation of NRF2 protein levels by enhancement of Nrf2 transcription, especially at 20 mg/kg NaAsO2 exposure group. In the meantime, mRNA and protein levels of Nrf2 encoding antioxidant enzymes heme oxygenase-1 (HO-1), NAD(P)H: quinine oxidoreductase 1 (NQO1) and glutathione S-transferase (GST) were consistently elevated time- and dose-dependently both in the cerebral cortex and hippocampus. Taken together, the presence study demonstrated the activation of NRF2 pathway, an early antioxidant defensive response, in both cerebral cortex and hippocampus upon inorganic arsenic (iAs) exposure in vivo. A better knowledge on the roles of NRF2 pathway in maintaining cellular redox homeostasis would be helpful for the strategies on improvement of neurotoxicity related to this metalloid.

  7. Significance of the rapid increase in GSH levels in the protective response to cadmium exposure through phosphorylated Nrf2 signaling in Jurkat T-cells.

    Science.gov (United States)

    Ogasawara, Yuki; Takeda, Yuko; Takayama, Hazuki; Nishimoto, Shouichi; Ichikawa, Keisuke; Ueki, Maiko; Suzuki, Toshihiro; Ishii, Kazuyuki

    2014-04-01

    Although cadmium (Cd) is a redox system disruptor, the systematic defensive responses to Cd-induced oxidative stress remain unclear. In this study, we initially determined that when human T-cell-derived Jurkat cells were exposed to a low concentration of Cd, the glutathione (GSH) concentration rapidly increased via the transient nuclear accumulation of the transcription factor Nrf2. Therefore, we hypothesized that this increase in the GSH levels was a significant event that occurred in response to the Cd toxicity in the Jurkat T-cells. To test this hypothesis, the expression of Nrf2 in the cells was silenced using siRNA transfection. These restricted expression conditions demonstrated that the sensitivity of the Jurkat T-cells to Cd toxicity was significantly higher in the knockdown cells. Whereas we could not find differences in the metallothionein (MT) expression responses, accumulation of Nrf2 in the nuclei and the GSH increase after Cd exposure were clearly suppressed in the Nrf2 knockdown cells. These findings strongly suggest that the Cd-induced activation of GSH synthesis is initiated as an acute response for Cd detoxification. Furthermore, the Cd remaining in the Jurkat T-cells did not cause a significant inhibition of cell growth after the rapid and transient increase in the GSH concentration returned to its basal level. Additionally, we found that MT expression induced by Cd occurred much later, with the expression seen at least 12h or more after the Nrf2-dependent immediate responses were almost completed. These results indicate that the rapid increase in GSH is an essential defensive response, with the subsequent induction of MT potentially chelating the Cd retained in the cell, thereby leading to continued suppression of Cd toxicity. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Antimalarial Drug Artemether Inhibits Neuroinflammation in BV2 Microglia Through Nrf2-Dependent Mechanisms.

    Science.gov (United States)

    Okorji, Uchechukwu P; Velagapudi, Ravikanth; El-Bakoush, Abdelmeneim; Fiebich, Bernd L; Olajide, Olumayokun A

    2016-11-01

    Artemether, a lipid-soluble derivative of artemisinin has been reported to possess anti-inflammatory properties. In this study, we have investigated the molecular mechanisms involved in the inhibition of neuroinflammation by the drug. The effects of artemether on neuroinflammation-mediated HT22 neuronal toxicity were also investigated in a BV2 microglia/HT22 neuron co-culture. To investigate effects on neuroinflammation, we used LPS-stimulated BV2 microglia treated with artemether (5-40 μM) for 24 h. ELISAs and western blotting were used to detect pro-inflammatory cytokines, nitric oxide, prostaglandin E 2 (PGE 2 ), inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and microsomal prostaglandin E synthase-1 (mPGES-1). Beta-site amyloid precursor protein cleaving enzyme 1 (BACE-1) activity and Aβ levels were measured with ELISA kits. Protein levels of targets in nuclear factor kappa B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) signalling, as well as heme oxygenase-1 (HO-1), NQO1 and nuclear factor-erythroid 2-related factor 2 (Nrf2) were also measured with western blot. NF-κB binding to the DNA was investigated using electrophoretic mobility shift assays (EMSA). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), DNA fragmentation and reactive oxygen species (ROS) assays in BV2-HT22 neuronal co-culture were used to evaluate the effects of artemether on neuroinflammation-induced neuronal death. The role of Nrf2 in the anti-inflammatory activity of artemether was investigated in BV2 cells transfected with Nrf2 siRNA. Artemether significantly suppressed pro-inflammatory mediators (NO/iNOS, PGE 2 /COX-2/mPGES-1, tumour necrosis factor-alpha (TNFα) and interleukin (IL)-6); Aβ and BACE-1 in BV2 cells following LPS stimulation. These effects of artemether were shown to be mediated through inhibition of NF-κB and p38 MAPK signalling. Artemether produced increased levels of HO-1, NQO1 and GSH in BV2 microglia. The drug

  9. Thyroid Hormone-Induced Cytosol-to-Nuclear Translocation of Rat Liver Nrf2 Is Dependent on Kupffer Cell Functioning

    Science.gov (United States)

    Videla, Luis A.; Cornejo, Pamela; Romanque, Pamela; Santibáñez, Catherine; Castillo, Iván; Vargas, Romina

    2012-01-01

    L-3,3′,5-triiodothyronine (T3) administration upregulates nuclear factor-E2-related factor 2 (Nrf2) in rat liver, which is redox-sensitive transcription factor mediating cytoprotection. In this work, we studied the role of Kupffer cell respiratory burst activity, a process related to reactive oxygen species generation and liver homeostasis, in Nrf2 activation using the macrophage inactivator gadolinium chloride (GdCl3; 10 mg/kg i.v. 72 h before T3 [0.1 mg/kg i.p.]) or NADPH oxidase inhibitor apocynin (1.5 mmol/L added to the drinking water for 7 days before T3), and determinations were performed 2 h after T3. T3 increased nuclear/cytosolic Nrf2 content ratio and levels of heme oxygenase 1 (HO-1), catalytic subunit of glutamate cysteine ligase, and thioredoxin (Western blot) over control values, proteins whose gene transcription is induced by Nrf2. These changes were suppressed by GdCl3 treatment prior to T3, an agent-eliciting Kupffer-cell depletion, inhibition of colloidal carbon phagocytosis, and the associated respiratory burst activity, with enhancement in nuclear inhibitor of Nrf2 kelch-like ECH-associated protein 1 (Keap1)/Nrf2 content ratios suggesting Nrf2 degradation. Under these conditions, T3-induced tumor necrosis factor-α (TNF-α) response was eliminated by previous GdCl3 administration. Similar to GdCl3, apocynin given before T3 significantly reduced liver Nrf2 activation and HO-1 expression, a NADPH oxidase inhibitor eliciting abolishment of colloidal carbon-induced respiratory burst activity without altering carbon phagocytosis. It is concluded that Kupffer cell functioning is essential for upregulation of liver Nrf2-signaling pathway by T3. This contention is supported by suppression of the respiratory burst activity of Kupffer cells and the associated reactive oxygen species production by GdCl3 or apocynin given prior to T3, thus hindering Nrf2 activation. PMID:22649286

  10. Phloretamide, an apple phenolic compound, activates the Nrf2/ARE pathway in human hepatocytes.

    Science.gov (United States)

    Krajka-Kuźniak, Violetta; Paluszczak, Jarosław; Celewicz, Lech; Barciszewski, Jan; Baer-Dubowska, Wanda

    2013-01-01

    The aim of this study was to evaluate the effect of phloretamide (PA), an apple constituent, on the activation of the Nrf2 transcription factor and the expression of its target genes: glutathione S-transferases (GSTs), NAD(P)H:quinone oxidoreductase-1 (NQO1) and heme oxygenase-1 (HO-1) in normal human THLE-2 hepatocytes and the hepatoma HepG2 cell line. PA did not show significant cytotoxicity towards THLE-2 cells but such an effect was observed in HepG2 cells (IC(50) ∼200μM). The treatment of cells with PA resulted in the translocation of Nrf2 from cytosol to nucleus in both cell lines, but increased the level of its transcript and protein only in THLE-2 cells. In this cell line an increased level of GSTA, GSTP, GSTT, NQO1 mRNA was also observed. Increased expression of GSTs was confirmed by enhancement of their protein levels. The increase in p53 protein content observed in THLE-2 may be associated with its stabilization induced by the enhancement of NQO1 level. PA did not affect Nrf2, GSTs, NQO1 or HO-1 expression in HepG2 cells. These results suggest that PA has rather chemopreventive than chemiotherapeutic potential and acts similarly as apple dihydrochalcones through the induction of detoxification/antioxidative enzymes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Bardoxolone methyl (BARD) ameliorates aristolochic acid (AA)-induced acute kidney injury through Nrf2 pathway.

    Science.gov (United States)

    Wu, Juan; Liu, Xinhui; Fan, Jinjin; Chen, Wenfang; Wang, Juan; Zeng, Youjia; Feng, Xiaorang; Yu, Xueqing; Yang, Xiao

    2014-04-06

    Bardoxolone methyl (BARD) is an antioxidant modulator that acts through induction of the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. This study aimed to investigate the role of BARD in protecting kidneys from aristolochic acid (AA)-induced acute kidney injury (AKI). Male C57BL/6 mice received intraperitoneal (i.p.) injections of aristolochic acid I (AAI) (5mg/kg/day) for 5 days to produce acute AA nephropathy (AAN) model. BARD (10mg/kg/day, i.p.) was applied for 7 consecutive days, starting 2 days prior to AAI administration. The mice in the AA group showed AKI as evidenced by worsening kidney function evaluated by blood urea nitrogen (BUN) and serum creatinine (SCr) levels, and severe tubulointerstitial injury marked by massive tubule necrosis in kidney tissues. BARD significantly reduced BUN and SCr levels which were elevated by AAI. Additionally, AAI-induced histopathological renal damage was ameliorated by BARD. Furthermore, the expression of Nrf2 was reduced, and its repressor Kelch-like ECH-associated protein 1 (Keap1) was increased significantly, whereas heme oxygenase-1 (HO-1) was upregulated and NAD(P)H quinone oxidoreductase-1 (NQO1) was barely increased in the cytoplasm of tubules in kidneys after treatment with AAI. BARD significantly upregulated renal Nrf2, NQO1 and HO-1 expression and downregulated Keap1 expression compared with those in the AA group. Moreover, it was found that Nrf2 was expressed both in the cytoplasm and nuclear of glomeruli and tubules, whereas NQO1 and HO-1 were localized in the cytoplasm of tubules only. In conclusion, AA-induced acute renal injury was associated with impaired Nrf2 activation and expression of its downstream target genes in renal tissues. BARD prevented renal damage induced by AAI, and this renoprotective effect may be exerted by activating the Nrf2 signaling pathway and increasing expression of the downstream target genes. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Nrf2 Inhibits Periodontal Ligament Stem Cell Apoptosis under Excessive Oxidative Stress

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    Yanli Liu

    2017-05-01

    Full Text Available The present study aimed to analyze novel mechanisms underlying Nrf2-mediated anti-apoptosis in periodontal ligament stem cells (PDLSCs in the periodontitis oxidative microenvironment. We created an oxidative stress model with H2O2-treated PDLSCs. We used real-time PCR, Western blotting, TUNEL staining, fluorogenic assay and transfer genetics to confirm the degree of oxidative stress and apoptosis as well as the function of nuclear factor-erythroid 2-related factor 2 (Nrf2. We demonstrated that with upregulated levels of reactive oxygen species (ROS and malondialdehyde (MDA, the effect of oxidative stress was obvious under H2O2 treatment. Oxidative molecules were altered after the H2O2 exposure, whereby the signaling of Nrf2 was activated with an increase in its downstream effectors, heme oxygenase-1 (HO-1, NAD(PH:quinone oxidoreductase 1 (NQO1 and γ-glutamyl cysteine synthetase (γ-GCS. Additionally, the apoptosis levels gradually increased with oxidative stress by the upregulation of caspase-9, caspase-3, Bax and c-Fos levels in addition to the downregulation of Bcl-2. However, there was no alterations in levels of caspase-8. The enhanced antioxidant effect could not mitigate the occurrence of apoptosis. Furthermore, Nrf2 overexpression effectively improved the anti-oxidative levels and increased cell proliferation. At the same time, overexpression effectively restrained TUNEL staining and decreased the molecular levels of caspase-9, caspase-3, Bax and c-Fos, but not that of caspase-8. In contrast, silencing the expression of Nrf2 levels had the opposite effect. Collectively, Nrf2 alleviates PDLSCs via its effects on regulating oxidative stress and anti-intrinsic apoptosis by the activation of oxidative enzymes.

  13. Dimethylfumarate attenuates restenosis after acute vascular injury by cell-specific and Nrf2-dependent mechanisms

    Directory of Open Access Journals (Sweden)

    Chang Joo Oh

    2014-01-01

    Full Text Available Excessive proliferation of vascular smooth muscle cells (VSMCs and incomplete re-endothelialization is a major clinical problem limiting the long-term efficacy of percutaneous coronary angioplasty. We tested if dimethylfumarate (DMF, an anti-psoriasis drug, could inhibit abnormal vascular remodeling via NF−E2-related factor 2 (Nrf2-NAD(PH quinone oxidoreductase 1 (NQO1 activity. DMF significantly attenuated neointimal hyperplasia induced by balloon injury in rat carotid arteries via suppression of the G1 to S phase transition resulting from induction of p21 protein in VSMCs. Initially, DMF increased p21 protein stability through an enhancement in Nrf2 activity without an increase in p21 mRNA. Later on, DMF stimulated p21 mRNA expression through a process dependent on p53 activity. However, heme oxygenase-1 (HO-1 or NQO1 activity, well-known target genes induced by Nrf2, were dispensable for the DMF induction of p21 protein and the effect on the VSMC proliferation. Likewise, DMF protected endothelial cells from TNF-α-induced apoptosis and the dysfunction characterized by decreased eNOS expression. With knock-down of Nrf2 or NQO1, DMF failed to prevent TNF-α-induced cell apoptosis and decreased eNOS expression. Also, CD31 expression, an endothelial specific marker, was restored in vivo by DMF. In conclusion, DMF prevented abnormal proliferation in VSMCs by G1 cell cycle arrest via p21 upregulation driven by Nrf2 and p53 activity, and had a beneficial effect on TNF-α-induced apoptosis and dysfunction in endothelial cells through Nrf2–NQO1 activity suggesting that DMF might be a therapeutic drug for patients with vascular disease.

  14. Serum oxidative stress-induced repression of Nrf2 and GSH depletion: a mechanism potentially involved in endothelial dysfunction of young smokers.

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    Anna Fratta Pasini

    Full Text Available Although oxidative stress plays a major role in endothelial dysfunction (ED, the role of glutathione (GSH, of nuclear erythroid-related factor 2 (Nrf2 and of related antioxidant genes (ARE are yet unknown. In this study we combined an in vivo with an in vitro model to assess whether cigarette smoking affects flow-mediated vasodilation (FMD, GSH concentrations and the Nrf2/ARE pathway in human umbilical vein endothelial cells (HUVECs.52 healthy subjects (26 non-smokers and 26 heavy smokers were enrolled in this study. In smokers we demonstrated increased oxidative stress, i.e., reduced concentrations of GSH and increased concentrations of oxidation products of the phospholipid 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphorylcholine (oxPAPC in serum and in peripheral blood mononuclear cells (PBMC, used as in vivo surrogates of endothelial cells. Moreover we showed impairment of FMD in smokers and a positive correlation with the concentration of GSH in PBMC of all subjects. In HUVECs exposed to smokers' serum but not to non-smokers' serum we found that oxidative stress increased, whereas nitric oxide and GSH concentrations decreased; interestingly the expression of Nrf2, of heme oxygenase-1 (HO-1 and of glutamate-cysteine ligase catalytic (GCLC subunit, the rate-limiting step of synthesis of GSH, was decreased. To test the hypothesis that the increased oxidative stress in smokers may have a causal role in the repression of Nrf2/ARE pathway, we exposed HUVECs to increasing concentrations of oxPAPC and found that at the highest concentration (similar to that found in smokers' serum the expression of Nrf2/ARE pathway was reduced. The knockdown of Nrf2 was associated to a significant reduction of HO-1 and GCLC expression induced by oxPAPC in ECs.In young smokers with ED a novel further consequence of increased oxidative stress is a repression of Nrf2/ARE pathway leading to GSH depletion.

  15. Antcin C from Antrodia cinnamomea Protects Liver Cells Against Free Radical-Induced Oxidative Stress and Apoptosis In Vitro and In Vivo through Nrf2-Dependent Mechanism

    Directory of Open Access Journals (Sweden)

    M. Gokila Vani

    2013-01-01

    Full Text Available In this study, we investigated the cytoprotective effects of antcin C, a steroid-like compound isolated from Antrodia cinnamaomea against AAPH-induced oxidative stress and apoptosis in human hepatic HepG2 cells. Pretreatment with antcin C significantly protects hepatic cells from AAPH-induced cell death through the inhibition of ROS generation. Furthermore, AAPH-induced lipid peroxidation, ALT/AST secretion and GSH depletion was significantly inhibited by antcin C. The antioxidant potential of antcin C was correlated with induction of antioxidant genes including, HO-1, NQO-1, γ-GCLC, and SOD via transcriptional activation of Nrf2. The Nrf2 activation by antcin C is mediated by JNK1/2 and PI3K activation, whereas pharmacologic inhibition of JNK1/2 and PI3K abolished antcin C-induced Nrf2 activity. In addition, AAPH-induced apoptosis was significantly inhibited by antcin C through the down-regulation of pro-apoptotic factors including, Bax, cytochrome c, capase 9, -4, -12, -3, and PARP. In vivo studies also show that antcin C significantly protected mice liver from AAPH-induced hepatic injury as evidenced by reduction in hepatic enzymes in circulation. Further, immunocytochemistry analyses showed that antcin C significantly increased HO-1 and Nrf2 expression in mice liver tissues. These results strongly suggest that antcin C could protect liver cells from oxidative stress and cell death via Nrf2/ARE activation.

  16. Coenzyme Q10 Supplementation Modulates NFκB and Nrf2 Pathways in Exercise Training

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    Ragip Pala, Cemal Orhan, Mehmet Tuzcu, Nurhan Sahin, Shakir Ali, Vedat Cinar, Mustafa Atalay, Kazim Sahin

    2016-03-01

    Full Text Available This study reports the effects of Q10, coenzyme Q10 or ubiquinone, a component of the electron transport chain in mitochondria, on nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB, inhibitors of kappa B (IκB, nuclear factor (erythroid-derived 2-like 2 (Nrf2 and hemeoxygenase 1 (HO-1 in rats after chronic exercise training for 6 weeks. 8-week old male Wistar rats were assigned randomly to one of four treatments planned in a 2 x 2 factorial arrangement of two condition (sedentary vs. exercise training, and two coenzyme Q10 levels (0 and 300 mg/kg per day for 6 weeks. The expression levels of the target proteins were determined in the heart, liver and muscle, and biochemical parameters including creatinine, urea, glucose and lipid profile were investigated in plasma. When compared with sedentary group, significant decreases in heart, liver and muscle NFκB levels by 45%, 26% and 44% were observed in Q10 supplemented rats after exercise training, respectively, while the inhibitory protein IκB increased by 179%, 111% and 127% in heart, liver and muscle tissues. Q10 supplementation caused an increase in Nrf2 (167%, 165% and 90% and HO-1 (107%, 156% and 114% after exercise training in heart, liver and muscle tissues (p < 0.05. No significant change was observed in any of the parameters associated with protein, carbohydrate and lipid metabolism, except that exercise caused a decrease in plasma triglyceride, which was further decreased by Q10. In conclusion, these results suggest that Q10 modulates the expression of NFκB, IκB, Nrf2 and HO-1 in exercise training, indicating an anti-inflammatory effect of Q10 and emphasizes its role in antioxidant defense.

  17. Synthesis and Nrf2 Activating Ability of Thiourea and Vinyl Sulfoxide Derivatives

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    Shim, Young Sun; Hwang, Hyun Sook; Nam, Ghilsoo; Choi, Kyung Il [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2013-08-15

    Thiourea and vinyl sulfoxide derivatives were designed based on the structures of sulforaphene and gallic acid, prepared and tested for HO-1 inducing activity as a measure of Nrf2 activation, and inhibitory effect on NO production as a measure of anti-inflammatory activity. Both series of compounds showed moderate activity on HO-1 induction, and no inhibitory effect on NO production. Interestingly the thiourea compound 6d showed better HO-1 induction (71% SFN) than the corresponding isothiocyanate compound 6a (55% SFN). Overall, it seemed that more efficient electrophile is needed to get more effective Nrf2 activator.

  18. Salidroside Suppresses HUVECs Cell Injury Induced by Oxidative Stress through Activating the Nrf2 Signaling Pathway

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    Yao Zhu

    2016-08-01

    Full Text Available Oxidative stress plays an important role in the pathogenesis of cardiovascular diseases. Salidroside (SAL, one of the main effective constituents of Rhodiola rosea, has been reported to suppress oxidative stress-induced cardiomyocyte injury and necrosis by promoting transcription of nuclear factor E2-related factor 2 (Nrf2-regulated genes such as heme oxygenase-1 (HO-1 and NAD(PH dehydrogenase (quinone1 (NQO1. However, it has not been indicated whether SAL might ameliorate endothelial injury induced by oxidative stress. Here, our study demonstrated that SAL might suppress HUVEC cell injury induced by oxidative stress through activating the Nrf2 signaling pathway. The results of our study indicated that SAL decreased the levels of intercellular reactive oxygen species (ROS and malondialdehyde (MDA, and improved the activities of superoxide dismutase (SOD and catalase (CAT, resulting in protective effects against oxidative stress-induced cell damage in HUVECs. It suppressed oxidative stress damage by inducing Nrf2 nuclear translocation and activating the expression of Nrf2-regulated antioxidant enzyme genes such as HO-1 and NQO1 in HUVECs. Knockdown of Nrf2 with siRNA abolished the cytoprotective effects against oxidative stress, decreased the expression of Nrf2, HO-1, and NQO1, and inhibited the nucleus translocation of Nrf2 in HUVECs. This study is the first to demonstrate that SAL suppresses HUVECs cell injury induced by oxidative stress through activating the Nrf2 signaling pathway.

  19. BQ123 Stimulates Skeletal Muscle Antioxidant Defense via Nrf2 Activation in LPS-Treated Rats

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    Agata Kowalczyk

    2016-01-01

    Full Text Available Little is understood of skeletal muscle tissue in terms of oxidative stress and inflammation. Endothelin-1 is an endogenous, vasoconstrictive peptide which can induce overproduction of reactive oxygen species and proinflammatory cytokines. The aim of this study was to evaluate whether BQ123, an endothelin-A receptor antagonist, influences the level of TNF-α, IL-6, SOD-1, HO-1, Nrf2 mRNA, and NF-κB subunit RelA/p65 mRNA in the femoral muscle obtained from endotoxemic rats. Male Wistar rats were divided into 4 groups (n=6 and received iv (1 saline (control, (2 LPS (15 mg/kg, (3 BQ123 (1 mg/kg, (4 BQ123 (1 mg/kg, and LPS (15 mg/kg, resp. 30 min later. Injection of LPS led to significant increase in levels of RelA/p65 mRNA, TNF-α, and IL-6, while content of SOD-1, HO-1, and Nrf2 mRNA was unchanged. Administration of BQ123 prior to LPS challenge resulted in a significant reduction in RelA/p65 mRNA, TNF-α, and IL-6 levels, as well as markedly elevated concentrations of SOD-1, HO-1, and Nrf2 mRNA. BQ123 appears to enhance antioxidant defense and prevent production of TNF-α and IL-6 in skeletal muscle of LPS-treated rat. In conclusion, endothelin-A receptor antagonism exerts significant impact on the skeletal muscle favouring anti-inflammatory effects and protection against oxidative stress.

  20. Nrf2 mediates redox adaptations to exercise

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    Aaron J. Done

    2016-12-01

    Full Text Available The primary aim of this review is to summarize the current literature on the effects of acute exercise and regular exercise on nuclear factor erythroid 2-related factor 2 (Nrf2 activity and downstream targets of Nrf2 signaling. Nrf2 (encoded in humans by the NFE2L2 gene is the master regulator of antioxidant defenses, a transcription factor that regulates expression of more than 200 cytoprotective genes. Increasing evidence indicates that Nrf2 signaling plays a key role in how oxidative stress mediates the beneficial effects of exercise. Episodic increases in oxidative stress induced through bouts of acute exercise stimulate Nrf2 activation and when applied repeatedly, as with regular exercise, leads to upregulation of endogenous antioxidant defenses and overall greater ability to counteract the damaging effects of oxidative stress. The evidence of Nrf2 activation in response to exercise across variety of tissues may be an important mechanism of how exercise exerts its well-known systemic effects that are not limited to skeletal muscle and myocardium. Additionally there are emerging data that results from animal studies translate to humans.

  1. The effect of Nrf2 pathway activation on human pancreatic islet cells.

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    Yuichi Masuda

    Full Text Available Pancreatic islets are known to contain low level of antioxidants that renders them vulnerable to oxidative stress. Nrf2 is the master regulator of numerous genes, encoding antioxidant, detoxifying, and cytoprotective molecules. Activation of Nrf2 pathway induces up-regulation of numerous genes encoding antioxidant and phase II detoxifying enzymes and related proteins. However, little is known regarding the role of this pathway in human islet cells. The aim was to investigate the effect of Nrf2 activator (dh404, CDDO-9,11-dihydro-trifluoroethyl amide on human islet cells.Human islets were obtained from cadaveric donors. After dh404 treatment, Nrf2 translocation, mRNA expression, and protein abundance of its key target gene products were examined. The proportion of dh404-treated or non-treated viable islet beta cells was analyzed using flowcytemetry. The cytoprotective effects against oxidative stress and production of inflammatory mediators, and in vivo islet function after transplantation were determined.Nrf2 nuclear translocation was confirmed by con-focal microscope within 2 hours after treatment, which was associated with a dose-dependent increase in mRNA expression of anti-oxidants, including NQO1, HO-1, and GCLC. Enhanced HO-1 expression in dh404 treated islets was confirmed by Western Blot assay. Islet function after transplantation (2000 IEQ/mouse to diabetic nude mice was not affected with or without dh404 treatment. After induction of oxidative stress with hydrogen peroxide (200 μM the proportion of dh404-treated viable islet cells was significantly higher in the dh404-treated than untreated islets (74% vs.57%; P<0.05. Dh404 significantly decreased production of cytokines/chemokines including IL-1β, IL-6, IFN-γ and MCP-1.Treatment of human pancreatic islets with the potent synthetic Nrf2 activator, dh404, significantly increased expression of the key anti-oxidants enzymes, decreased inflammatory mediators in islets and conferred

  2. Nrf2 activation prevents cadmium-induced acute liver injury

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    Wu, Kai C. [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Liu, Jie J. [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Klaassen, Curtis D., E-mail: cklaasse@kumc.edu [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States)

    2012-08-15

    Oxidative stress plays an important role in cadmium-induced liver injury. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that up-regulates cytoprotective genes in response to oxidative stress. To investigate the role of Nrf2 in cadmium-induced hepatotoxicity, Nrf2-null mice, wild-type mice, kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2, and Keap1-hepatocyte knockout (Keap1-HKO) mice with maximum Nrf2 activation were treated with cadmium chloride (3.5 mg Cd/kg, i.p.). Blood and liver samples were collected 8 h thereafter. Cadmium increased serum alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities, and caused extensive hepatic hemorrhage and necrosis in the Nrf2-null mice. In contrast, Nrf2-enhanced mice had lower serum ALT and LDH activities and less morphological alternations in the livers than wild-type mice. H{sub 2}DCFDA (2′,7′-dichlorodihydrofluoresein diacetate) staining of primary hepatocytes isolated from the four genotypes of mice indicated that oxidative stress was higher in Nrf2-null cells, and lower in Nrf2-enhanced cells than in wild-type cells. To further investigate the mechanism of the protective effect of Nrf2, mRNA of metallothionein (MT) and other cytoprotective genes were determined. Cadmium markedly induced MT-1 and MT-2 in livers of all four genotypes of mice. In contrast, genes involved in glutathione synthesis and reducing reactive oxygen species, including glutamate-cysteine ligase (Gclc), glutathione peroxidase-2 (Gpx2), and sulfiredoxin-1 (Srxn-1) were only induced in Nrf2-enhanced mice, but not in Nrf2-null mice. In conclusion, the present study shows that Nrf2 activation prevents cadmium-induced oxidative stress and liver injury through induction of genes involved in antioxidant defense rather than genes that scavenge Cd. -- Highlights: ► Cadmium caused extensive hepatic hemorrhage and necrosis in Nrf2-null mice. ► Keap1-KD and Keap1-HKO mice

  3. Salidroside's Protection Against UVB-Mediated Oxidative Damage and Apoptosis Is Associated with the Upregulation of Nrf2 Expression.

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    Yuan, Xiao-Ying; Pang, Xiao-Wen; Zhang, Guo-Qiang; Guo, Jian-You

    2017-01-01

    Salidroside is the major active component of Rhodiola rosea, a traditional Chinese herbal medicine used for protection against ultraviolet (UV) radiation. This study investigated whether salidroside can protect skin from ultraviolet B (UVB)-induced oxidative damage in human immortalized HaCaT keratinocytes and the skin of guinea pigs. Using HaCaT cell models, the effects of salidroside on oxidative damage and possible regulatory factors [including NF-E2-related factor 2 (Nrf2), NAD(P)H-quinone oxidoreductase (NQO1), and heme oxygenase 1 (HO-1)] were examined. In addition, the regulatory effects of salidroside on apoptotic sunburn cells (SBCs) and 8-hydroxy-2'-deoxyguanosine (8-OHdG)-positive epidermal cells on UVB-exposed guinea pig skin were also investigated. We found that salidroside pretreatment upregulated Nrf2 translocation to the nucleus and transcription activity in HaCaT cells, as reflected by the increased nuclear accumulation of Nrf2 as well as the gene and protein expression of downstream Nrf2 antioxidants, including NQO1 and HO-1. In addition, we also found that pretreatment with salidroside reactive oxygen species (ROS) in irradiated HaCaT cells. The oral administration of salidroside (0.1% w/w) to guinea pigs inhibited the UVB-mediated formation of apoptotic SBCs and 8-OHdG-positive epidermal cells in the skin of guinea pigs. Our results show that UVB-induced oxidative damage can be prevented by salidroside with upregulation of nuclear Nrf2 expression.

  4. Green tea polyphenol (−)-epigallocatechin-3-gallate triggered hepatotoxicity in mice: Responses of major antioxidant enzymes and the Nrf2 rescue pathway

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    Wang, Dongxu; Wang, Yijun; Wan, Xiaochun [Key Laboratory of Tea Biochemistry & Biotechnology, School of Tea & Food Science, Anhui Agricultural University, Hefei, Anhui 230036 (China); Yang, Chung S. [Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Zhang, Jinsong, E-mail: zjs@ahau.edu.cn [Key Laboratory of Tea Biochemistry & Biotechnology, School of Tea & Food Science, Anhui Agricultural University, Hefei, Anhui 230036 (China)

    2015-02-15

    (−)-Epigallocatechin-3-gallate (EGCG), a constituent of green tea, has been suggested to have numerous health-promoting effects. On the other hand, high-dose EGCG is able to evoke hepatotoxicity. In the present study, we elucidated the responses of hepatic major antioxidant enzymes and nuclear factor erythroid 2-related factor 2 (Nrf2) rescue pathway to high-dose levels of EGCG in Kunming mice. At a non-lethal toxic dose (75 mg/kg, i.p.), repeated EGCG treatments markedly decreased the levels of superoxide dismutase, catalase, and glutathione peroxidase. As a rescue response, the nuclear distribution of Nrf2 was significantly increased; a battery of Nrf2-target genes, including heme oxygenase 1 (HO1), NAD(P)H:quinone oxidoreductase 1 (NQO1), glutathione S-transferase (GST), and those involved in glutathione and thioredoxin systems, were all up-regulated. At the maximum tolerated dose (45 mg/kg, i.p.), repeated EGCG treatments did not disturb the major antioxidant defense. Among the above-mentioned genes, only HO1, NQO1, and GST genes were significantly but modestly up-regulated, suggesting a comprehensive and extensive activation of Nrf2-target genes principally occurs at toxic levels of EGCG. At a lethal dose (200 mg/kg, i.p.), a single EGCG treatment dramatically decreased not only the major antioxidant defense but also the Nrf2-target genes, demonstrating that toxic levels of EGCG are able to cause a biphasic response of Nrf2. Overall, the mechanism of EGCG-triggered hepatotoxicity involves suppression of major antioxidant enzymes, and the Nrf2 rescue pathway plays a vital role for counteracting EGCG toxicity. - Highlights: • EGCG at maximum tolerated dose does not disturb hepatic major antioxidant defense. • EGCG at maximum tolerated dose modestly upregulates hepatic Nrf2 target genes. • EGCG at toxic dose suppresses hepatic major antioxidant enzymes. • EGCG at non-lethal toxic dose pronouncedly activates hepatic Nrf2 rescue response. • EGCG at

  5. Ursodeoxycholic Acid Attenuates Acute Aortic Dissection Formation in Angiotensin II-Infused Apolipoprotein E-Deficient Mice Associated with Reduced ROS and Increased Nrf2 Levels

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    Wanjun Liu

    2016-03-01

    Full Text Available Background/Aims: Acute aortic dissection (AAD is characterized by excessive smooth muscle cell (SMC loss, extracellular matrix (ECM degradation and inflammation. In response to certain stimulations, oxidative stress is activated and regulates apoptosis and inflammation. Excessive apoptosis promotes aortic inflammation and degeneration, leading to AAD formation. This study aimed to clarify role of oxidative stress in the pathogenesis of AAD and whether the antioxidant ursodeoxycholic acid (UDCA attenuates AAD formation. Methods: Angiotensin II (Ang II was infused in 8-months male ApoE-/- mice for one week to establish a model of AAD. UDCA (10 mg/kg/day was administered via intragastric gavage for 3 consecutive days before AngII infusion and also during the AngII infusion for another consecutive 7 days. Results: Ang II-infusion resulted in the incidence of AAD at a rate of 35% (13/37 and UDCA markedly reduced the incidence of AAD to 16% (6/37, accompanied with reduced maximal aortic diameter measured at the suprarenal region of the abdominal aorta. Additionally, UDCA pretreatment prevented Ang II induced generations of reactive oxygen species (ROS and apoptosis of vascular smooth muscle cells (VSMCs both in vivo and in. vitro Mechanistically, we found UDCA markedly increased Nrf2 expression in VSMCs and prevented Ang II induced expression of NADPH subunits (p47, p67 and gp91 in Nrf2-dependent manner and rescued the activity of redox enzymes (Cu/Zn-SOD, Mn-SOD and CAT, thereby inhibiting apoptosis of VSMCs. Conclusion: These results demonstrate that UDCA prevented AAD formation by reducing apoptosis of VSMCs caused by oxidative stress in Nrf2 dependent manner and suggest that UDCA might have clinical potential to suppress AAD formation.

  6. The crosstalk between Nrf2 and AMPK signal pathways is important for the anti-inflammatory effect of berberine in LPS-stimulated macrophages and endotoxin-shocked mice.

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    Mo, Chunfen; Wang, Ling; Zhang, Jie; Numazawa, Satoshi; Tang, Hong; Tang, Xiaoqiang; Han, Xiaojuan; Li, Junhong; Yang, Ming; Wang, Zhe; Wei, Dandan; Xiao, Hengyi

    2014-02-01

    The response of AMP-activated protein kinase (AMPK) to oxidative stress has been recently reported but the downstream signals of this response are largely unknown. Meanwhile, the upstream events for the activation of nuclear factor erythroid-2-related factor-2 (Nrf2), a critical transcriptional activator for antioxidative responses, remain unclear. In the present study, we investigated the relationship between AMPK and Nrf2 signal pathways in lipopolysaccharide (LPS)-triggered inflammatory system, in which berberine (BBR), a known AMPK activator, was used for inflammation suppression. In inflammatory macrophages, BBR attenuated LPS-induced expression of inflammatory genes (inducible nitric oxide synthase [iNOS], cyclooxygenase-2 [COX2], interleukin [IL]-6), and the generation of nitric oxide and reactive oxygen species, but increased the transcription of Nrf2-targeted antioxidative genes (NADPH quinone oxidoreductase-1 [NQO-1], heme oxygenase-1 [HO-1]), as well as the nuclear localization and phosphorylation of Nrf2 protein. Importantly, we found BBR-induced activation of Nrf2 is AMPK-dependent, as either pharmacologically or genetically inactivating AMPK blocked the activation of Nrf2. Consistent with in vitro experiments, BBR down-regulated the expression of proinflammatory genes but upregulated those of Nrf2-targeted genes in lungs of LPS-injected mice, and these effects were attenuated in Nrf2-deficient mice. Moreover, the effect of BBR on survival time extension and plasma redox regulation in endotoxin-shocked mice was largely weakened when Nrf2-depleted. Our results demonstrate convergence between AMPK and Nrf2 pathways and this intersection is essential for anti-inflammatory effect of BBR in LPS-stimulated macrophages and endotoxin-shocked mice. Uncovering this intersection is significant for understanding the relationship between energy homeostasis and antioxidative responses and may be beneficial for developing new therapeutic strategies against

  7. Selenium antagonizes cadmium-induced apoptosis in chicken spleen but not involving Nrf2-regulated antioxidant response.

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    Chen, Menghao; Li, Xiaojing; Fan, Ruifeng; Cao, Changyu; Yao, Haidong; Xu, Shiwen

    2017-11-01

    The nuclear transcription factor NF-E2-related factor 2 (Nrf2) binds to antioxidant response elements (AREs) and is involved in the regulation of genes participated in defending cells against oxidative damage, which have been confirmed in animal models. Selenium (Se), known as an important element in the regulation of antioxidant activity, can antagonize Cadmium (Cd) toxicity in birds. However, the role of Nrf2 in selenium-cadmium interaction has not been reported in birds. To further explore the mechanism of selenium attenuating spleen toxicity induced by cadmium in chickens, cadmium chloride (CdCl 2 , 150mg/kg) and sodium selenite (Na 2 SeO 3 , 2mg/kg) were co-administrated or individually administered in the diet of chickens for 90 days. The results showed that Cd exposure increased the level of hydrogen peroxide (H 2 O 2 ) and malondialdehyde (MDA) and decreased the antioxidant enzyme activities, including superoxide dismutase (SOD), glutathione peroxidase (Gpx), total antioxidative capacity (T-AOC), catalase (CAT). Cd exposure increased obviously nuclear accumulation of Nrf2, and the expression of Nrf2 downstream heme oxygenase-1 (HO-1) and NAD(P)H: quinine oxidoreductase 1 (NQO1), reduced the expression of Kelch-like ECH-associated protein (keap1), Gpx-1 and thioredoxin reductase-1 (TrxR1). In addition, Cd induced the increase of bak, caspase9, p53, Cyt c mRNA levels, increased bax/bcl-2 ratio, increased caspase3 mRNA and protein levels. Selenium treatment reduced the accumulation of Cd in the spleen, attenuates Cd-induced Nrf2 nuclear accumulation, enhanced antioxidant enzyme activities, ameliorated Cd-induced oxidative stress and apoptosis in the spleen. In summary, our results demonstrate that Se ameliorated spleen toxicity induced by cadmium by modulating the antioxidant system, independently of Nrf2-regulated antioxidant response pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Comparative evaluation of the sexual functions and NF-κB and Nrf2 pathways of some aphrodisiac herbal extracts in male rats.

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    Sahin, Kazim; Orhan, Cemal; Akdemir, Fatih; Tuzcu, Mehmet; Gencoglu, Hasan; Sahin, Nurhan; Turk, Gaffari; Yilmaz, Ismet; Ozercan, Ibrahim H; Juturu, Vijaya

    2016-08-26

    Mucuna pruriens, Tribulus terrestris and Ashwagandha (Withania somnifera) are widely known as antioxidant effective herbals and have been reported to possess aphrodisiac activities in traditional usages. In this study, we determined the effects of these herbals on sexual functions, serum biochemical parameters, oxidative stress and levels of NF-κB, Nrf2, and HO-1 in reproductive tissues. Thirty-five male rats were divided into five groups: the control group, sildenafil-treated group (5 mg/kg/d), Mucuna, Tribulus and Ashwagandha groups. The extract groups were treated orally either with Mucuna, Tribulus or Ashwagandha (300 mg/kg b.w.) for 8 weeks. All of the extracts were found to be significantly effective in sexual functioning and antioxidant capacity and Tribulus showed the highest effectiveness. Serum testosterone levels significantly increased in Tribulus and Ashwagandha groups in comparison to control group. Tribulus was able to reduce the levels of NF-κB and increase the levels of Nrf2 and HO-1 to a much greater extent than Mucuna and Ashwagandha. These results demonstrate for the first time that Mucuna, Tribulus and Ashwagandha supplementation improves sexual function in male rats via activating Nrf2/ HO-1 pathway while inhibiting the NF-κB levels. Moreover, Tribulus terrestris extract was found to be more bioavailable from Ashwagandha extract followed by Mucuna extract. Schematic representation of the mode of action of some aphrodisiac herbal extracts to improve sexual functions.

  9. Mechanisms underlying the perifocal neuroprotective effect of the Nrf2–ARE signaling pathway after intracranial hemorrhage

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    Yin XP

    2015-11-01

    Full Text Available Xiao-ping Yin,1,2 Zhi-ying Chen,2 Jun Zhou,1 Dan Wu,1,3 Bing Bao2 1Department of Neurology, The Second Affiliated Hospital of Nanchang University, Nanchang, People’s Republic of China; 2Department of Neurology, Affiliated Hospital of Jiujiang University, Jiujiang, People’s Republic of China; 3Department of Neurology, The Sixth Hospital of Wuhan, Wuhan, People’s Republic of China Background: It has been found that nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2–ARE signaling pathway plays a role in antioxidative response, anti-inflammatory response, and neuron-protection in intracerebral hemorrhage (ICH. The aim of this study is to explore mechanisms underlying the perifocal neuroprotective effect of the Nrf2–ARE signaling pathway after ICH.Methods: There were a total of 90 rats with basal ganglia hemorrhage, which were randomly divided into the following four groups: ICH (Sprague–Dawley rats with autologous femoral arterial blood injection into the basal ganglia, sulforaphane (SFN (SFN was intraperitoneally administered into rats, retinoic acid (RA (RA was intraperitoneally administered into rats, and dimethyl sulfoxide (the rats were treated with dimethyl sulfoxide. We observed the neurological score of the rats in the different groups, and collected brain tissues for immunofluorescence, Western blot, and reverse transcription polymerase chain reaction to detect expression of Nrf2, heme oxygenase (HO-1, nuclear factor-κB (NF-κB, and tumor necrosis factor-α (TNF-α.Results: The results indicated that neurological dysfunction of rats was significantly improved in the SFN group, and the expressions of Nrf2 and HO-1 in tissues surrounding the hemorrhage were increased. Also, the level of NF-κB and TNF-α were reduced compared to the ICH group. The RA group exhibited more severe neurological dysfunction and lower levels of Nrf2 and HO-1 than the SFN and ICH groups. Compared to the ICH group, the NF

  10. Quercetin ameliorates learning and memory via the Nrf2-ARE signaling pathway in d-galactose-induced neurotoxicity in mice.

    Science.gov (United States)

    Dong, Fuxing; Wang, Shuang; Wang, Yiwen; Yang, Xiao; Jiang, Jiali; Wu, Dejian; Qu, Xuebin; Fan, Hongbin; Yao, Ruiqin

    2017-09-23

    Aging is accompanied by deficits in cognitive function and neuronal degeneration or loss. Quercetin is a flavonoid that exhibits powerful antioxidant activity. This study evaluated the protective effects and mechanisms of quercetin in d-galactose-induced neurotoxicity in mice. Quercetin was administered daily at doses of 20 or 50 mg/kg in d-galactose-injected (50 mg/kg/subcutaneous (s.c.)) mice for eight weeks. Morris water maze tests demonstrated that quercetin significantly improved learning and memory compared to d-galactose-treated control mice. Quercetin also prevented changes in the neuronal cell morphology and apoptosis in the hippocampus as well as increased the expression of Nrf2, HO-1 and SOD in d-galactose-treated mice. Treatment with the Nrf2 inhibitor Brusatol reversed the effects of quercetin on HO-1 and SOD expression as well as neuronal cell protection. In conclusion, quercetin protected mice from d-galactose-induced cognitive functional impairment and neuronal cell apoptosis via activation of the Nrf2-ARE signaling pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Fluvastatin inhibits AGE-induced cell proliferation and migration via an ERK5-dependent Nrf2 pathway in vascular smooth muscle cells.

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    Ae-Rang Hwang

    Full Text Available Advanced glycation endproduct (AGE-induced vascular smooth muscle cell (VSMC proliferation and reactive oxygen species (ROS production are emerging as important mechanisms of diabetic vasculopathy, but little is known about the molecular mechanism responsible for the antioxidative effects of statins on AGEs. It has been reported that statins exert pleiotropic effects on the cardiovascular system due to decreases in AGE-induced cell proliferation, migration, and vascular inflammation. Thus, in the present study, the authors investigated the molecular mechanism by which statins decrease AGE-induced cell proliferation and VSMC migration. In cultured VSMCs, statins upregulated Nrf2-related antioxidant gene, NQO1 and HO-1, via an ERK5-dependent Nrf2 pathway. Inhibition of ERK5 by siRNA or BIX02189 (a specific ERK5 inhibitor reduced the statin-induced upregulations of Nrf2, NQO1, and HO-1. Furthermore, fluvastatin was found to significantly increase ARE promoter activity through ERK5 signaling, and to inhibit AGE-induced VSMC proliferation and migration as determined by MTT assay, cell counting, FACS analysis, a wound scratch assay, and a migration chamber assay. In addition, AGE-induced proliferation was diminished in the presence of Ad-CA-MEK5α encoding a constitutively active mutant form of MEK5α (an upstream kinase of ERK5, whereas depletion of Nrf2 restored statin-mediated reduction of AGE-induced cell proliferation. Moreover, fluvastatin suppressed the protein expressions of cyclin D1 and Cdk4, but induced p27, and blocked VSMC proliferation by regulating cell cycle. These results suggest statin-induced activation of an ERK5-dependent Nrf2 pathway reduces VSMC proliferation and migration induced by AGEs, and that the ERK5-Nrf2 signal module be viewed as a potential therapeutic target of vasculopathy in patients with diabetes and complications of the disease.

  12. Uric acid demonstrates neuroprotective effect on Parkinson's disease mice through Nrf2-ARE signaling pathway.

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    Huang, Ting-Ting; Hao, Dong-Lin; Wu, Bo-Na; Mao, Lun-Lin; Zhang, Jin

    2017-12-02

    Uric acid has neuroprotective effect on Parkinson's disease (PD) by inhibiting oxidative damage and neuronal cell death. Our previous study has shown that uric acid protected dopaminergic cell line damage through inhibiting accumulation of NF-E2-related factor 2 (Nrf2). This study aimed to investigate its in vivo neuroprotective effect. PD was induced by MPTP intraperitoneally injection for 7 d in male C57BL/6 mice. Mice were treated with either uric acid (intraperitoneally injection 250 mg/kg) or saline for a total of 13 d. We showed that uric acid improved behavioral performances and cognition of PD mice, increased TH-positive dopaminergic neurons and decreased GFAP-positive astrocytes in substantia nigra (SN). Uric acid increased mRNA and protein expressions of Nrf2 and three Nrf2-responsive genes, including γ-glutamate-cysteine ligase catalytic subunit (γ-GCLC), heme oxygenase-1 (HO-1) and NQO1. Uric acid significantly increased superoxide dismutase (SOD), CAT, glutathione (GSH) levels and decreased malondialdehyde (MDA) level in SN regions of MPTP-treated mice. Uric acid inhibited the hippocampal expression of IL-1β and decreased serum and hippocampus levels of interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α). In conclusion, uric acid demonstrates neuroprotective properties for dopaminergic neurons in PD mice through modulation of neuroinflammation and oxidative stress. Copyright © 2017. Published by Elsevier Inc.

  13. TBHQ Alleviated Endoplasmic Reticulum Stress-Apoptosis and Oxidative Stress by PERK-Nrf2 Crosstalk in Methamphetamine-Induced Chronic Pulmonary Toxicity

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    Yun Wang

    2017-01-01

    Full Text Available Methamphetamine (MA leads to cardiac and pulmonary toxicity expressed as increases in inflammatory responses and oxidative stress. However, some interactions may exist between oxidative stress and endoplasmic reticulum stress (ERS. The current study is designed to investigate if both oxidative stress and ERS are involved in MA-induced chronic pulmonary toxicity and if antioxidant tertiary butylhydroquinone (TBHQ alleviated ERS-apoptosis and oxidative stress by PERK-Nrf2 crosstalk. In this study, the rats were randomly divided into control group, MA-treated group (MA, and MA plus TBHQ-treated group (MA + TBHQ. Chronic exposure to MA resulted in slower growth of weight and pulmonary toxicity of the rats by increasing the pulmonary arterial pressure, promoting the hypertrophy of right ventricle and the remodeling of pulmonary arteries. MA inhibited the Nrf2-mediated antioxidative stress by downregulation of Nrf2, GCS, and HO-1 and upregulation of SOD2. MA increased GRP78 to induce ERS. Overexpression and phosphorylation of PERK rapidly phosphorylated eIF2α, increased ATF4, CHOP, bax, caspase 3, and caspase 12, and decreased bcl-2. These changes can be reversed by antioxidant TBHQ through upregulating expression of Nrf2. The above results indicated that TBHQ can alleviate MA-induced oxidative stress which can accelerate ERS to initiate PERK-dependent apoptosis and that PERK/Nrf2 is likely to be the key crosstalk between oxidative stress and ERS in MA-induced chronic pulmonary toxicity.

  14. UVA Irradiation Enhances Brusatol-Mediated Inhibition of Melanoma Growth by Downregulation of the Nrf2-Mediated Antioxidant Response

    Directory of Open Access Journals (Sweden)

    Mei Wang

    2018-01-01

    Full Text Available Brusatol (BR is a potent inhibitor of Nrf2, a transcription factor that is highly expressed in cancer tissues and confers chemoresistance. UVA-generated reactive oxygen species (ROS can damage both normal and cancer cells and may be of potential use in phototherapy. In order to provide an alternative method to treat the aggressive melanoma, we sought to investigate whether low-dose UVA with BR is more effective in eliminating melanoma cells than the respective single treatments. We found that BR combined with UVA led to inhibition of A375 melanoma cell proliferation by cell cycle arrest in the G1 phase and triggers cell apoptosis. Furthermore, inhibition of Nrf2 expression attenuated colony formation and tumor development from A375 cells in heterotopic mouse models. In addition, cotreatment of UVA and BR partially suppressed Nrf2 and its downstream target genes such as HO-1 along with the PI3K/AKT pathway. We propose that cotreatment increased ROS-induced cell cycle arrest and cellular apoptosis and inhibits melanoma growth by regulating the AKT-Nrf2 pathway in A375 cells which offers a possible therapeutic intervention strategy for the treatment of human melanoma.

  15. Protective Effect of Tempol on Acute Kidney Injury Through PI3K/Akt/Nrf2 Signaling Pathway.

    Science.gov (United States)

    Zhang, Gensheng; Wang, Qiaoling; Zhou, Qin; Wang, Renjun; Xu, Minze; Wang, Huiping; Wang, Lei; Wilcox, Christopher S; Liu, Ruisheng; Lai, En Yin

    2016-01-01

    Tempol is a protective antioxidant against ischemic injury in many animal models. The molecular mechanisms are not well understood. Nuclear factor erythroid 2-related factor (Nrf2) is a master transcription factor during oxidative stress, which is enhanced by activation of protein kinase C (PKC) pathway. Another factor, tubular epithelial apoptosis, is mediated by activation of phosphoinositide 3-kinase (PI3K)/protein kinase B (PKB, Akt) signaling pathway during renal ischemic injury. We tested the hypothesis that tempol activates PKC or PI3K/Akt/Nrf2 pathways to transcribe many genes that coordinate endogenous antioxidant defense. The right renal pedicle was clamped for 45 minutes and the left kidney was removed to study renal ischemia/reperfusion (I/R) injury in C57BL/6 mice. The response was assessed from serum parameters, renal morphology and renal expression of PKC, phosphorylated-PKC (p-PKC), Nrf2, heme oxygenase-1 (HO-1), Akt, phosphorylated-Akt (p-Akt), pro-caspase-3 and cleaved caspase-3 in groups of sham and I/R mice given vehicle, or tempol (50 or 100 mg/kg, intraperitoneal injection). The serum malondialdehyde (MDA, marker of reactive oxygen species) doubled and the BUN and creatinine increased 5- to 10-fold after I/R injury. Tempol (50 or 100 mg/kg) prevented the increases in MDA but only tempol (50 mg/kg) lessened the increases in BUN and creatinine and moderated the acute tubular necrosis. I/R did not change expression of PKC or p-PKC but reduced renal expression of Nrf2, p-Akt, HO-1 and pro-caspase-3 and increased cleaved caspase-3. Tempol (50 mg/kg) prevented these changes produced by I/R whereas tempol (100 mg/kg) had lesser or inconsistent effects. Tempol (50 mg/kg) prevents lipid peroxidation and attenuates renal damage after I/R injury. The beneficial pathway apparently is not dependent on upregulation or phosphorylation of PKC, at lower tempol doses, does implicate upregulation of Akt with expression of Nrf2 that could account for the increase

  16. Protective Effect of Tempol on Acute Kidney Injury Through PI3K/Akt/Nrf2 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Gensheng Zhang

    2016-02-01

    Full Text Available Background/Aims: Tempol is a protective antioxidant against ischemic injury in many animal models. The molecular mechanisms are not well understood. Nuclear factor erythroid 2-related factor (Nrf2 is a master transcription factor during oxidative stress, which is enhanced by activation of protein kinase C (PKC pathway. Another factor, tubular epithelial apoptosis, is mediated by activation of phosphoinositide 3-kinase (PI3K/protein kinase B (PKB, Akt signaling pathway during renal ischemic injury. We tested the hypothesis that tempol activates PKC or PI3K/Akt/Nrf2 pathways to transcribe many genes that coordinate endogenous antioxidant defense. Methods: The right renal pedicle was clamped for 45 minutes and the left kidney was removed to study renal ischemia/reperfusion (I/R injury in C57BL/6 mice. The response was assessed from serum parameters, renal morphology and renal expression of PKC, phosphorylated-PKC (p-PKC, Nrf2, heme oxygenase-1 (HO-1, Akt, phosphorylated-Akt (p-Akt, pro-caspase-3 and cleaved caspase-3 in groups of sham and I/R mice given vehicle, or tempol (50 or 100 mg/kg, intraperitoneal injection. Results: The serum malondialdehyde (MDA, marker of reactive oxygen species doubled and the BUN and creatinine increased 5- to 10-fold after I/R injury. Tempol (50 or 100 mg/kg prevented the increases in MDA but only tempol (50 mg/kg lessened the increases in BUN and creatinine and moderated the acute tubular necrosis. I/R did not change expression of PKC or p-PKC but reduced renal expression of Nrf2, p-Akt, HO-1 and pro-caspase-3 and increased cleaved caspase-3. Tempol (50 mg/kg prevented these changes produced by I/R whereas tempol (100 mg/kg had lesser or inconsistent effects. Conclusion: Tempol (50 mg/kg prevents lipid peroxidation and attenuates renal damage after I/R injury. The beneficial pathway apparently is not dependent on upregulation or phosphorylation of PKC, at lower tempol doses, does implicate upregulation of Akt with

  17. Reduction of DNA damage induced by titanium dioxide nanoparticles through Nrf2 in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Zhiqin [Department of Toxicology, Hebei Medical University, Shijiazhuang (China); Department of Laboratory Diagnosis, Hebei Medical University, Shijiazhuang (China); Niu, Yujie [Department of Occupational Health and Environmental Health, Hebei Medical University, Shijiazhuang (China); Wang, Qian [Department of Toxicology, Hebei Medical University, Shijiazhuang (China); Shi, Lei [Department of Occupational Health and Environmental Health, Hebei Medical University, Shijiazhuang (China); Guo, Huicai; Liu, Yi; Zhu, Yue [Department of Toxicology, Hebei Medical University, Shijiazhuang (China); Liu, Shufeng; Liu, Chao [Hebei Keylab of Laboratory Animal Science, Shijiazhuang (China); Chen, Xin [Xiumen Community Health Service Centre, Shijiazhuang (China); Zhang, Rong, E-mail: rongzhang@hebmu.edu.cn [Department of Toxicology, Hebei Medical University, Shijiazhuang (China); Hebei Keylab of Laboratory Animal Science, Shijiazhuang (China)

    2015-11-15

    Highlights: • Nrf2 signals were partly responsible for the DNA damage induced by Nano-TiO{sub 2}. • Nrf2 loss could aggravate the DNA damage induced by Nano-TiO{sub 2}. • Acquired Nrf2 decreased the susceptibility to DNA damage induced by Nano-TiO{sub 2}. - Abstract: Titanium dioxide nanoparticles (Nano-TiO{sub 2}) are widely used to additives in cosmetics, pharmaceutical, paints and foods. Recent studies have demonstrated that Nano-TiO{sub 2} induces DNA damage and increased the risk of cancer and the mechanism might relate with oxidative stress. The aim of this study was to evaluate the effects of Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), an anti-oxidative mediator, on DNA damage induced by Nano-TiO{sub 2}. Wildtype, Nrf2 knockout (Nrf2(-/-)) and tert-butylhydroquinone (tBHQ) pre-treated HepG2 cells and mice were treated with Nano-TiO{sub 2}. And then the oxidative stress and DNA damage were evaluated. Our data showed that DNA damage, reactive oxygen species (ROS) generation and MDA content in Nano-TiO{sub 2} exposed cells were significantly increased than those of control in dose dependent manners. Nrf2/ARE droved the downstream genes including NAD(P)H dehydrogenase [quinine] 1(NQO1), heme oxygenase 1 (HO-1) and glutamate-cysteine ligase catalytic subunit (GCLC) expression were significantly higher in wildtype HepG2 cells after Nano-TiO{sub 2} treatment. After treatment with Nano-TiO{sub 2}, the DNA damages were significantly increased in Nrf(-/-) cells and mice whereas significantly decreased in tBHQ pre-treatment cells and mice, compared with the wildtype HepG2 cells and mice, respectively. Our results indicated that the acquired of Nrf2 leads to a decreased susceptibility to DNA damages induction by Nano-TiO{sub 2} and decreasing of risk of cancer which would provide a strategy for a more efficacious sensitization of against of Nano-TiO{sub 2} toxication.

  18. Activation of p62-keap1-Nrf2 antioxidant pathway in the early stage of acetaminophen-induced acute liver injury in mice.

    Science.gov (United States)

    Shen, Zhenyu; Wang, Yu; Su, Zhenhui; Kou, Ruirui; Xie, Keqin; Song, Fuyong

    2018-02-25

    Acetaminophen (APAP) overdose can cause severe liver failure even death. Nearly half of drug-induced liver injury is attributed to APAP in the US and many European countries. Oxidative stress has been validated as a critical event involved in APAP-induced liver failure. p62/SQSTM1, a selective autophagy adaptor protein, is reported to regulate Nrf2-ARE antioxidant pathway in response to oxidative stress. However, the exact role of p62-keap1-Nrf2 antioxidant pathway in APAP-induced hepatotoxicity remains unknown. In the present study, the dose-response and time-course model in C57/BL6 mice were established by intraperitoneal injection of APAP. The results of serum alanine/aspartate aminotransferases (ALT/AST) and histological examination demonstrated that APAP overdose resulted in the severe liver injury. In the meantime, the levels of p62, phospho-p62 and nuclear Nrf2 were significantly increased by APAP in mice liver, suggesting an activation of p62-keap1-Nrf2 pathway. In addition, the expression of GSTA1 mRNA was increased in a dose-dependent manner, while the mRNA levels of HO-1 and GCLC were decreased with the increase of APAP dose. Our further investigation found that expression of HO-1 and GCLC peaked at 3 h∼6 h, and then were decreased gradually. Taken together, these results indicated that p62-keap1-Nrf2 antioxidant pathway was primarily activated in the early stage of APAP hepatotoxicity, which might play a protective role in the process of APAP-induced acute liver injury. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Induction of NRF2-mediated gene expression by dietary phytochemical flavones apigenin and luteolin.

    Science.gov (United States)

    Paredes-Gonzalez, Ximena; Fuentes, Francisco; Jeffery, Sundrina; Saw, Constance Lay-Lay; Shu, Limin; Su, Zheng-Yuan; Kong, Ah-Ng Tony

    2015-10-01

    Apigenin (API) and luteolin (LUT) have been used as therapeutic agents in folk medicine for thousands of years. These compounds exert a variety of biological activities, including anticancer, antioxidant and antiinflammatory activities. This study investigated whether API and LUT could activate Nrf2-antioxidant response element (ARE)-mediated gene expression and induce antiinflammatory activities in human hepatoma HepG2 cells. The compounds did not exhibit any substantial toxicity at low doses (1.56-6.25 µm). The induction of ARE activity was assessed in HepG2-C8 cells after treatment with low doses of API and LUT for 6 and 12 h. It was found that the induction of ARE activity by these compounds at the higher doses was comparable to the effects of the positive control, SFN at a dose of 6.25 µm. Exposure to the PI3K inhibitor LY294002 abolished ARE activation by both API and LUT, whereas the ERK-1/2 inhibitor PD98059 only decreased ARE activity induced by API. Both compounds significantly increased the endogenous mRNA and protein levels of Nrf2 and Nrf2 target genes with important effects on heme oxygenase-1 (HO-1) expression. API and LUT significantly and dose-dependently decreased the production of nitric oxide (NO), nitric oxide synthase (iNOS) and cytosolic phospholipase A2 (cPLA2), which were induced by the treatment of HepG2 cells with 1 µg/ml of lipopolysaccharide (LPS) for 24 h. The results indicate that API and LUT significantly activate the PI3K/Nrf2/ARE system, and this activation may be responsible for their antiinflammatory effects, as demonstrated by the suppression of LPS-induced NO, iNOS and cPLA2. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Nrf2 and Cardiovascular Defense

    Directory of Open Access Journals (Sweden)

    Reuben Howden

    2013-01-01

    Full Text Available The cardiovascular system is susceptible to a group of diseases that are responsible for a larger proportion of morbidity and mortality than any other disease. Many cardiovascular diseases are associated with a failure of defenses against oxidative stress-induced cellular damage and/or death, leading to organ dysfunction. The pleiotropic transcription factor, nuclear factor-erythroid (NF-E 2-related factor 2 (Nrf2, regulates the expression of antioxidant enzymes and proteins through the antioxidant response element. Nrf2 is an important component in antioxidant defenses in cardiovascular diseases such as atherosclerosis, hypertension, and heart failure. Nrf2 is also involved in protection against oxidant stress during the processes of ischemia-reperfusion injury and aging. However, evidence suggests that Nrf2 activity does not always lead to a positive outcome and may accelerate the pathogenesis of some cardiovascular diseases (e.g., atherosclerosis. The precise conditions under which Nrf2 acts to attenuate or stimulate cardiovascular disease processes are unclear. Further studies on the cellular environments related to cardiovascular diseases that influence Nrf2 pathways are required before Nrf2 can be considered a therapeutic target for the treatment of cardiovascular diseases.

  1. Andrographolide exerts anti-hepatitis C virus activity by up-regulating haeme oxygenase-1 via the p38 MAPK/Nrf2 pathway in human hepatoma cells.

    Science.gov (United States)

    Lee, Jin-Ching; Tseng, Chin-Kai; Young, Kung-Chia; Sun, Hung-Yu; Wang, Shainn-Wei; Chen, Wei-Chun; Lin, Chun-Kuang; Wu, Yu-Hsuan

    2014-01-01

    This study aimed to evaluate the anti-hepatitis C virus (HCV) activity of andrographolide, a diterpenoid lactone extracted from Andrographis paniculata, and to identify the signalling pathway involved in its antiviral action. Using HCV replicon and HCVcc infectious systems, we identified anti-HCV activity of andrographolide by measuring protein and RNA levels. A reporter activity assay was used to determine transcriptional regulation of anti-HCV agents. A specific inhibitor and short hairpin RNAs were used to investigate the mechanism responsible for the effect of andrographolide on HCV replication. In HCV replicon and HCVcc infectious systems, andrographolide time- and dose-dependently suppressed HCV replication. When combined with IFN-α, an inhibitor targeting HCV NS3/4A protease (telaprevir), or NS5B polymerase (PSI-7977), andrographolide exhibited a significant synergistic effect. Andrographolide up-regulated the expression of haeme oxygenase-1 (HO-1), leading to increased amounts of its metabolite biliverdin, which was found to suppress HCV replication by promoting the antiviral IFN responses and inhibiting NS3/4A protease activity. Significantly, these antiviral effects were attenuated by an HO-1-specific inhibitor or HO-1 gene knockdown, indicating that HO-1 contributed to the anti-HCV activity of andrographolide. Andrographolide activated p38 MAPK phosphorylation, which stimulated nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated HO-1 expression, and this was found to be associated with its anti-HCV activity. Our results demonstrate that andrographolide has the potential to control HCV replication and suggest that targeting the Nrf2-HO-1 signalling pathway might be a promising strategy for drug development. © 2013 The British Pharmacological Society.

  2. Hydrogen gas reduces hyperoxic lung injury via the Nrf2 pathway in vivo

    Science.gov (United States)

    Kawamura, Tomohiro; Wakabayashi, Nobunao; Shigemura, Norihisa; Huang, Chien-Sheng; Masutani, Kosuke; Tanaka, Yugo; Noda, Kentaro; Peng, Ximei; Takahashi, Toru; Billiar, Timothy R.; Okumura, Meinoshin; Toyoda, Yoshiya; Kensler, Thomas W.

    2013-01-01

    Hyperoxic lung injury is a major concern in critically ill patients who receive high concentrations of oxygen to treat lung diseases. Successful abrogation of hyperoxic lung injury would have a huge impact on respiratory and critical care medicine. Hydrogen can be administered as a therapeutic medical gas. We recently demonstrated that inhaled hydrogen reduced transplant-induced lung injury and induced heme oxygenase (HO)-1. To determine whether hydrogen could reduce hyperoxic lung injury and investigate the underlying mechanisms, we randomly assigned rats to four experimental groups and administered the following gas mixtures for 60 h: 98% oxygen (hyperoxia), 2% nitrogen; 98% oxygen (hyperoxia), 2% hydrogen; 98% balanced air (normoxia), 2% nitrogen; and 98% balanced air (normoxia), 2% hydrogen. We examined lung function by blood gas analysis, extent of lung injury, and expression of HO-1. We also investigated the role of NF-E2-related factor (Nrf) 2, which regulates HO-1 expression, by examining the expression of Nrf2-dependent genes and the ability of hydrogen to reduce hyperoxic lung injury in Nrf2-deficient mice. Hydrogen treatment during exposure to hyperoxia significantly improved blood oxygenation, reduced inflammatory events, and induced HO-1 expression. Hydrogen did not mitigate hyperoxic lung injury or induce HO-1 in Nrf2-deficient mice. These findings indicate that hydrogen gas can ameliorate hyperoxic lung injury through induction of Nrf2-dependent genes, such as HO-1. The findings suggest a potentially novel and applicable solution to hyperoxic lung injury and provide new insight into the molecular mechanisms and actions of hydrogen. PMID:23475767

  3. Pro-oxidant status and Nrf2 levels in psoriasis vulgaris skin tissues and dimethyl fumarate-treated HaCaT cells.

    Science.gov (United States)

    Lee, Yoon Jin; Bae, Jin Ho; Kang, Sang-Gue; Cho, Sung Woo; Chun, Dong-Il; Nam, Seung Min; Kim, Chul Han; Nam, Hae Seon; Lee, Seon Hwa; Lee, Sang Han; Cho, Moon Kyun

    2017-09-01

    Reactive oxygen species (ROS) contribute to pathogenesis of many inflammatory skin diseases, including psoriasis. The aim of this study is to compare antioxidant protein expression in psoriasis vulgaris (PV) skin tissues with that in normal skin tissues in vivo and to evaluate the effects of dimethyl fumarate (DMF), used for the treatment of psoriasis, on ROS generation and apoptosis in a human keratinocyte cell line HaCaT. Compared with normal skin tissues, PV skin tissues showed increased protein oxidation as well as down-regulation of Nrf2 and its regulatory proteins such as HO-1 and AKR1C3. Using HaCaT cells to model DMF-induced pro-oxidant effects in the skin cells, we found that DMF treatment induced increased ROS levels and apoptotic cell death, as signified by increased proportion of cells with Annexin V-PE(+) staining and a sub-G 0 /G 1 peak in the cell cycle. Preceding these changes, DMF treatment resulted in up-regulation of Nrf2, HO-1, and AKR1C3 proteins in these cells. Collectively, increased oxidative stress and impaired cellular anti-oxidant enzyme systems may participate in the pathogenesis of PV. DMF may exert an additive therapeutic efficacy in PV by attenuating the redox burden and subsequent oxidative damage to normal keratinocytes through activation of Nrf2 pathway relative to PV.

  4. Age-related retinopathy in NRF2-deficient mice.

    Directory of Open Access Journals (Sweden)

    Zhenyang Zhao

    2011-04-01

    Full Text Available Cumulative oxidative damage is implicated in the pathogenesis of age-related macular degeneration (AMD. Nuclear factor erythroid 2-related factor 2 (NRF2 is a transcription factor that plays key roles in retinal antioxidant and detoxification responses. The purposes of this study were to determine whether NRF2-deficient mice would develop AMD-like retinal pathology with aging and to explore the underlying mechanisms.Eyes of both wild type and Nrf2(-/- mice were examined in vivo by fundus photography and electroretinography (ERG. Structural changes of the outer retina in aged animals were examined by light and electron microscopy, and immunofluorescence labeling. Our results showed that Nrf2(-/- mice developed age-dependent degenerative pathology in the retinal pigment epithelium (RPE. Drusen-like deposits, accumulation of lipofuscin, spontaneous choroidal neovascularization (CNV and sub-RPE deposition of inflammatory proteins were present in Nrf2(-/- mice after 12 months. Accumulation of autophagy-related vacuoles and multivesicular bodies was identified by electron microscopy both within the RPE and in Bruch's membrane of aged Nrf2(-/- mice.Our data suggest that disruption of Nfe2l2 gene increased the vulnerability of outer retina to age-related degeneration. NRF2-deficient mice developed ocular pathology similar to cardinal features of human AMD and deregulated autophagy is likely a mechanistic link between oxidative injury and inflammation. The Nrf2(-/- mice can provide a novel model for mechanistic and translational research on AMD.

  5. Nrf2 regulates cellular behaviors and Notch signaling in oral squamous cell carcinoma cells.

    Science.gov (United States)

    Fan, Hong; Paiboonrungruan, Chorlada; Zhang, Xinyan; Prigge, Justin R; Schmidt, Edward E; Sun, Zheng; Chen, Xiaoxin

    2017-11-04

    Oxidative stress is known to play a pivotal role in the development of oral squamous cell carcinoma (OSCC). We have demonstrated that activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway has chemopreventive effects against oxidative stress-associated OSCC. However, Nrf2 have dual roles in cancer development; while it prevents carcinogenesis of normal cells, hyperactive Nrf2 also promotes the survival of cancer cells. This study is aimed to understand the function of Nrf2 in regulating cellular behaviors of OSCC cells, and the potential mechanisms through which Nrf2 facilitates OSCC. We established the Nrf2-overexpressing and Nrf2-knockdown OSCC cell lines, and examined the function of Nrf2 in regulating cell proliferation, migration, invasion, cell cycle and colony formation. Our data showed that Nrf2 overexpression promoted cancer phenotypes in OSCC cells, whereas Nrf2 silencing inhibited these phenotypes. In addition, Nrf2 positively regulated Notch signaling pathway in OSCC cells in vitro. Consistent with this observation, Nrf2 activation in Keap1 -/- mice resulted in not only hyperproliferation of squamous epithelial cells in mouse tongue as evidenced by increased expression of PCNA, but also activation of Notch signaling in these cells as evidenced by increased expression of NICD1 and Hes1. In conclusion, Nrf2 regulates cancer behaviors and Notch signaling in OSCC cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Src subfamily kinases regulate nuclear export and degradation of transcription factor Nrf2 to switch off Nrf2-mediated antioxidant activation of cytoprotective gene expression.

    Science.gov (United States)

    Niture, Suryakant K; Jain, Abhinav K; Shelton, Phillip M; Jaiswal, Anil K

    2011-08-19

    Nrf2 (NF-E2-related factor 2) is a nuclear transcription factor that in response to chemical and radiation stress regulates coordinated induction of a battery of cytoprotective gene expressions leading to cellular protection. In this study, we investigated the role of Src kinases in the regulation of Nrf2 and downstream signaling. siRNA-mediated inhibition of Fyn, Src, Yes, and Fgr, but not Lyn, in mouse hepatoma Hepa-1 cells, led to nuclear accumulation of Nrf2 and up-regulation of Nrf2 downstream gene expression. Mouse embryonic fibroblasts with combined deficiency of Fyn/Src/Yes/Fgr supported results from siRNA. In addition, steady-state overexpression of Fyn, Src, and Yes phosphorylated Nrf2Tyr568 that triggered nuclear export and degradation of Nrf2 and down-regulation of Nrf2 downstream gene expression. Exposure of cells to antioxidant, oxidant, or UV radiation increased nuclear import of Fyn, Src, and Yes kinases, which phosphorylated Nrf2Tyr568 resulting in nuclear export and degradation of Nrf2. Further analysis revealed that stress-activated GSK3β acted upstream to the Src kinases and phosphorylated the Src kinases, leading to their nuclear localization and Nrf2 phosphorylation. The overexpression of Src kinases in Hepa-1 cells led to decreased Nrf2, increased apoptosis, and decreased cell survival. Mouse embryonic fibroblasts deficient in Src kinases showed nuclear accumulation of Nrf2, induction of Nrf2 and downstream gene expression, reduced apoptosis, and increased cell survival. The studies together demonstrate that Src kinases play a critical role in nuclear export and degradation of Nrf2, thereby providing a negative feedback mechanism to switch off Nrf2 activation and restore normal cellular homeostasis.

  7. Targeted disruption of Nrf2 causes regenerative immune-mediated hemolytic anemia

    Science.gov (United States)

    Lee, Jong-Min; Chan, Kaimin; Kan, Yuet Wai; Johnson, Jeffrey A.

    2004-01-01

    A basic leucine zipper transcription factor, NF-E2-related factor 2 (Nrf2), plays a critical role in the cellular defense mechanism by mediating a coordinate up-regulation of antioxidant responsive element-driven detoxification and antioxidant genes. Here, we report that targeted disruption of Nrf2 causes regenerative immune-mediated hemolytic anemia due to increased sequestration of damaged erythrocytes. Splenomegaly and spleen toxicity in Nrf2-/- mice raised a possibility of hemolytic anemia and splenic extramedullary hematopoiesis in Nrf2-/- mice. In support of this, hematology analysis revealed that Nrf2-/- mice suffer from anemia with abnormal red cell morphologies (i.e., Howell-Jolly bodies, acantocytes, and schistocytes). In addition, Nrf2-/- erythrocytes were more sensitive to H2O2-induced hemolysis, and erythrocyte-bound IgG levels were markedly increased in Nrf2-/- mice compared with Nrf2+/+ mice. Because IgG bound to erythrocytes in the presence of oxidative damage in erythrocytes (regardless of Nrf2 genotype), these data support that Nrf2-/- erythrocytes have higher levels of damage compared with Nrf2+/+ cells. Finally, Nrf2-/- mice showed increased levels of erythrocyte-bound IgG compared with Nrf2+/+ mice after H2O2 injection in vivo, suggesting that the decreased glutathione and increased H2O2 render the Nrf2-/- mice more susceptible to toxicity. Taken together, these observations indicate that a chronic increase in oxidative stress due to decreased antioxidant capacity sensitizes erythrocytes and causes hemolytic anemia in Nrf2-/- mice, suggesting a pivotal role of Nrf2-antioxidant responsive element pathway in the cellular antioxidant defense system. PMID:15210949

  8. Haeme oxygenase-1 overexpression via nAChRs and the transcription factor Nrf2 has antinociceptive effects in the formalin test.

    Science.gov (United States)

    Egea, Javier; Rosa, Angelo O; Lorrio, Silvia; del Barrio, Laura; Cuadrado, Antonio; López, Manuela G

    2009-11-01

    Epibatidine has shown antinociceptive effects in various pain models, being 200-fold more potent than morphine. Previous results from our laboratory demonstrated that HO-1 overexpression has an antinociceptive effect in the formalin test. Furthermore, epibatidine was able to induce haeme oxygenase-1 (HO-1). So, the aim of this study was to investigate the effect of HO-1 overexpression induced by epibatidine in nociception elicited by formalin injection in the mice hindpaw. Administration of epibatidine (4 microg/kg) 24h before the test reduced the nociceptive response during the first phase and second phase of the formalin test. This effect was prevented by treatment with tin protoporphyrin (SnPP, an inhibitor of HO-1 activity) administered via intraplantar 5min before the test, suggesting a main role of HO-1. Western blot analysis revealed that epibatidine treatment increased by 2-fold HO-1 expression in the paw; this effect was lost in knockout mice for nuclear factor-erythroid 2-related factor 2 (Nrf2) and was accompanied by the loss of its antinociceptive effect. Furthermore, the antinociceptive effect of epibatidine was related to the activation of alpha7 and/or alpha9 nAChRs since methyllycaconitine (MLA) and mecamylamine but not dihydro-beta-erythroidine (DHbetaE) reverted this effect. Finally, we showed by flow cytometry and by immunofluorescence that white blood cells of the animals injected with epibatidine expressed more HO-1 than control animals, and this expression was also reverted by MLA pre-treatment. These findings demonstrate that HO-1 induction by epibatidine has antinociceptive and anti-inflammatory effects by the activation of MLA-sensitive nAChRs.

  9. The nuclear cofactor RAC3/AIB1/SRC-3 enhances Nrf2 signaling by interacting with transactivation domains.

    Science.gov (United States)

    Kim, J-H; Yu, S; Chen, J D; Kong, A N

    2013-01-24

    Nuclear factor erythroid 2-related factor 2 (Nrf2, NM 006164, 605 AA) is essential for the antioxidant responsive element (ARE)-mediated expression of a group of detoxifying antioxidant genes that detoxify carcinogens and protect against oxidative stress. Several proteins have been identified as Nrf2-interacting molecules. In this study, we found that the overexpression of receptor-associated coactivator 3 (RAC3)/AIB-1/steroid receptor coactivator-3, a nuclear coregulator and oncogene frequently amplified in human breast cancers, induced heme oxygenase-1 (HO-1) through Nrf2 transactivation in HeLa cells. Next, we determined the interaction between RAC3 and Nrf2 proteins using a co-immunoprecipitation assay and fluorescence resonance energy transfer analysis. The results showed that RAC3 bound directly to the Nrf2 protein in the nucleus. Subsequently, we identified the interacting domains of Nrf2 and RAC3 using a glutathione S-transferase pull-down assay. The results showed that both the N-terminal RAC3-pasB and C-terminal RAC3-R3B3 domains were tightly bound to the Neh4 and Neh5 transactivation domains. Furthermore, chromatin immunoprecipitation showed that RAC3 bound tightly to the ARE enhancer region of the HO-1 promoter via Nrf2 binding. These data suggest that Nrf2 activation is modulated and directly controlled through interactions with the RAC3 protein in HeLa cells.

  10. Sulforaphane attenuates di-N-butylphthalate-induced reproductive damage in pubertal mice: Involvement of the Nrf2-antioxidant system.

    Science.gov (United States)

    Jiang, Xu-Ping; Tang, Jing-Yuan; Xu, Zhen; Han, Peng; Qin, Zhi-Qiang; Yang, Cheng-di; Wang, Shang-Qian; Tang, Min; Wang, Wei; Qin, Chao; Xu, Yang; Shen, Bai-Xin; Zhou, Wei-Min; Zhang, Wei

    2017-07-01

    di-N-butylphthalate (DBP) is a ubiquitous environmental pollutant used for plastic coating and in the cosmetics industry. It has toxic effects on body health, especially the male reproductive system. Here, we investigated the effects of DBP on the male reproductive system of pubertal mice and explored the protective role of sulforaphane (SFN). The results showed that DBP significantly reduced the anogenital distance, testicular weight, sperm count and motility, and plasma and testicular testosterone levels and significantly increased the oxidative stress, sperm abnormalities, and testicular cell apoptosis. SFN supplementation ameliorated these effects. After DBP stimulation, the transcription factor nuclear factor erythroid-related factor 2 (Nrf2) was adaptively increased together with its target genes, such as HO-1 and NQO1. Upregulation of Nrf2 by SFN reduced the DBP-mediated intracellular oxidative toxicity and also increased testosterone secretion and spermatogenesis, which were decreased by DBP. These findings indicate that SFN can attenuate DBP-induced reproductive damage in pubertal mice via Nrf2-associated pathways. © 2017 Wiley Periodicals, Inc.

  11. Sulforaphane Prevents Testicular Damage in Kunming Mice Exposed to Cadmium via Activation of Nrf2/ARE Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Shu-Hua Yang

    2016-10-01

    Full Text Available Sulforaphane (SFN is a natural and highly effective antioxidant. Studies suggest that SFN protects cells and tissues against cadmium (Cd toxicity. This study investigated the protective effect of SFN against oxidative damage in the testes of Kunming mice exposed to cadmium, and explored the possible molecular mechanisms involved. Cadmium greatly reduced the serum testosterone levels in mice, reduced sperm motility, total sperm count, and increased the sperm deformity rate. Cadmium also reduces superoxide dismutase (T-SOD and glutathione (GSH levels and increases malondialdehyde (MDA concentrations. SFN intervention improved sperm quality, serum testosterone, and antioxidant levels. Both mRNA and protein expression of mouse testicular nuclear factor-erythroid 2-related factor 2 (Nrf2 was reduced in cadmium-treated group. Furthermore, the downstream genes of Nrf2, glutathione peroxidase (GSH-Px, γ-glutamyl cysteine synthetase (γ-GCS, heme oxygenase-1 (HO-1, and NAD(PH:quinone oxidoreductase-1 (NQO1 were also decreased in cadmium-treated group. SFN intervention increases the expression of these genes. Sulforaphane prevents cadmium-induced testicular damage, probably via activation of Nrf2/ARE signaling.

  12. Targeting HO-1 by Epigallocatechin-3-Gallate Reduces Contrast-Induced Renal Injury via Anti-Oxidative Stress and Anti-Inflammation Pathways.

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    Zhao Gao

    Full Text Available Both oxidative stress and inflammation are involved in the pathogenesis of contrast-induced nephropathy (CIN. Epigallocatechin-3-gallate (EGCG, a purified catechin from green tea, has antioxidant and anti-inflammatory effects. However, it is unknown whether or not EGCG is effective in treating CIN. Our present study found that intravenous administration of EGCG, either before or just after the establishment of CIN, had a protective effect, determined by normalization of serum creatinine and blood urea nitrogen levels, improvement in renal histopathological scoring and alleviation of apoptosis, accompanied by decreased oxidative stress and inflammation. Because EGCG is a potent inducer of the antioxidant heme oxygenase-1 (HO-1, we studied HO-1 signaling in CIN. HO-1 levels were increased in CIN; treatment with EGCG further increased HO-1 levels, accompanied by an increase in Nrf2, a regulator of antioxidant proteins. Interestingly, blockade of HO-1 with protoporphyrin IX zinc(II (ZnPP prevented the protective effect of EGCG on CIN. ZnPP also blocked the ability of EGCG to increase the activity of an antioxidant (superoxide dismutase, and decrease markers of oxidative stress (myeloperoxidase and malondialdehyde and inflammation (myeloperoxidase and IL-1β, indicating that HO-1 is the upstream molecule that regulates the EGCG-mediated protection. To determine further the role of HO-1 on the EGCG-mediated inhibition of inflammation, we studied the effect of EGCG on the NLRP3 inflammasome, an upstream signaling of IL-1β. EGCG down-regulated NLRP3 expression, which was blocked by ZnPP, indicating that HO-1 links EGCG with NLRP3. Therefore, EGCG, via up-regulation of HO-1, protects against CIN by amelioration of oxidative stress and inflammation.

  13. Nrf2 is overexpressed in pancreatic cancer: implications for cell proliferation and therapy

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    Neoptolemos John P

    2011-04-01

    Full Text Available Abstract Background Nrf2 is a key transcriptional regulator of a battery of genes that facilitate phase II/III drug metabolism and defence against oxidative stress. Nrf2 is largely regulated by Keap1, which directs Nrf2 for proteasomal degradation. The Nrf2/Keap1 system is dysregulated in lung, head and neck, and breast cancers and this affects cellular proliferation and response to therapy. Here, we have investigated the integrity of the Nrf2/Keap1 system in pancreatic cancer. Results Keap1, Nrf2 and the Nrf2 target genes AKR1c1 and GCLC were detected in a panel of five pancreatic cancer cell lines. Mutation analysis of NRF2 exon 2 and KEAP1 exons 2-6 in these cell lines identified no mutations in NRF2 and only synonomous mutations in KEAP1. RNAi depletion of Nrf2 caused a decrease in the proliferation of Suit-2, MiaPaca-2 and FAMPAC cells and enhanced sensitivity to gemcitabine (Suit-2, 5-flurouracil (FAMPAC, cisplatin (Suit-2 and FAMPAC and gamma radiation (Suit-2. The expression of Nrf2 and Keap1 was also analysed in pancreatic ductal adenocarcinomas (n = 66 and 57, respectively and matching normal benign epithelium (n = 21 cases. Whilst no significant correlation was seen between the expression levels of Keap1 and Nrf2 in the tumors, interestingly, Nrf2 staining was significantly greater in the cytoplasm of tumors compared to benign ducts (P Conclusions Expression of Nrf2 is up-regulated in pancreatic cancer cell lines and ductal adenocarcinomas. This may reflect a greater intrinsic capacity of these cells to respond to stress signals and resist chemotherapeutic interventions. Nrf2 also appears to support proliferation in certain pancreatic adenocarinomas. Therefore, strategies to pharmacologically manipulate the levels and/or activity of Nrf2 may have the potential to reduce pancreatic tumor growth, and increase sensitivity to therapeutics.

  14. Totarol prevents neuronal injury in vitro and ameliorates brain ischemic stroke: Potential roles of Akt activation and HO-1 induction

    International Nuclear Information System (INIS)

    Gao, Yuanxue; Xu, Xiaojun; Chang, Sai; Wang, Yunjie; Xu, Yazhou; Ran, Siqi; Huang, Zhangjian; Li, Ping; Li, Jia; Zhang, Luyong; Saavedra, Juan M.; Liao, Hong; Pang, Tao

    2015-01-01

    The natural product totarol, a phenolic diterpenoid and a major constituent isolated from the sap of Podocarpus totara, has been reported to have a potent antimicrobial activity. In this study, we determined whether totarol possessed an additional neuroprotective activity in vitro and in vivo. We found that totarol prevented glutamate- and oxygen and glucose deprivation-induced neuronal death in primary rat cerebellar granule neuronal cells and cerebral cortical neurons. Totarol increased Akt and GSK-3β phosphorylation, Nrf2 and heme oxygenase-1 (HO-1) protein expressions and suppressed oxidative stress by increasing GSH and SOD activities. The PI3K/Akt inhibitor LY294002 prevented totarol neuroprotective effect by suppressing the totarol-induced changes in HO-1 expression and the activities of GSH and SOD. The HO-1 inhibitor ZnPPIX also prevented totarol-increased GSH and SOD activities. In a model of acute cerebral ischemic injury in Sprague–Dawley rats, produced by occlusion of the middle cerebral artery for 2 h followed by 22 h or 46 h of reperfusion, totarol significantly reduced infarct volume and improved the neurological deficit. In this model, totarol increased HO-1 expression and the activities of GSH and SOD. These observations suggest that totarol may be a novel activator of the Akt/HO-1 pathway protecting against ischemic stroke through reduction of oxidative stress. - Graphical abstract: It is unknown whether the natural product totarol has neuroprotective effects in vitro and in vivo. This study underscores that totarol prevents neuronal injury in vitro, not only by activating PI3K/Akt pathway, but also via induction of Nrf2, HO-1, GSH and SOD expressions. Totarol also ameliorated acute cerebral ischemic injury in a rat ischemic stroke model. The findings highlight that totarol may be exploited for protecting against ischemic stroke through Akt/HO-1 pathway. - Highlights: • Totarol protects glutamate- and OGD-induced neuronal injury in vitro.

  15. Mechanism of chemical activation of Nrf2.

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    Yun Li

    Full Text Available NF-E2 related factor-2 (Nrf2 promotes the transcription of many cytoprotective genes and is a major drug target for prevention of cancer and other diseases. Indeed, the cancer-preventive activities of several well-known chemical agents were shown to depend on Nrf2 activation. It is well known that chemopreventive Nrf2 activators stabilize Nrf2 by blocking its ubiquitination, but previous studies have indicated that this process occurs exclusively in the cytoplasm. Kelch-like ECH-associated protein 1 (Keap1 binds to Nrf2 and orchestrates Nrf2 ubiquitination, and it has been a widely-held view that inhibition of Nrf2 ubiquitination by chemopreventive agents results from the dissociation of Nrf2 from its repressor Keap1. Here, we show that while the activation of Nrf2 by prototypical chemical activators, including 5,6-dihydrocyclopenta-1,2-dithiole-3-thione (CPDT and sulforaphane (SF, results solely from inhibition of its ubiquitination, such inhibition occurs predominantly in the nucleus. Moreover, the Nrf2 activators promote Nrf2 association with Keap1, rather than disassociation, which appears to result from inhibition of Nrf2 phosphorylation at Ser40. Available evidence suggests the Nrf2 activators may block Nrf2 ubiquitination by altering Keap1 conformation via reaction with the thiols of specific Keap1 cysteines. We further show that while the inhibitory effects of CPDT and SF on Nrf2 ubiquitination depend entirely on Keap1, Nrf2 is also degraded by a Keap1-independent mechanism. These findings provide significant new insight about Nrf2 activation and suggest that exogenous chemical activators of Nrf2 enter the nucleus to exert most of their inhibitory impact on Nrf2 ubiquitination and degradation.

  16. Involvement of PKA and HO-1 signaling in anti-inflammatory effects of surfactin in BV-2 microglial cells

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    Park, Sun Young; Kim, Ji-Hee [Department of Molecular Biology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Keumjeong-gu, Busan 609-735 (Korea, Republic of); Lee, Sang Joon [Department of Microbiology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Keumjeong-gu, Busan 609-735 (Korea, Republic of); Kim, YoungHee, E-mail: yheekim@pusan.ac.kr [Department of Molecular Biology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Keumjeong-gu, Busan 609-735 (Korea, Republic of)

    2013-04-01

    Surfactin, one of the most powerful biosurfactants, is a bacterial cyclic lipopeptide. Here, we investigated the anti-neuroinflammatory properties of surfactin in lipoteichoic acid (LTA)-stimulated BV-2 microglial cells. Surfactin significantly inhibited excessive production of the pro-inflammatory mediators TNF-α, IL-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1), prostaglandin E{sub 2} (PGE{sub 2}), nitric oxide (NO) and reactive oxygen species (ROS), and suppressed the expression of matrix metalloproteinase-9 (MMP-9), inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Subsequent mechanistic studies revealed that surfactin inhibited LTA-induced nuclear factor-kappaB (NF-κB) and signal transducer and activator of transcription-1 (STAT-1) activation. However, surfactin increases the phosphorylation of the STAT-3, a component of the homeostatic mechanism causing anti-inflammatory events. We also demonstrated that surfactin induces heme oxygenase-1 (HO-1) expression and nuclear factor-regulated factor-2 (Nrf-2) activation, and that the anti-inflammatory effects of surfactin are abrogated by small interfering RNA-mediated knock-down of HO-1 or Nrf-2. Interestingly, we found that surfactin increased the level of cAMP and induced phosphorylation of cAMP responsive element binding protein (CREB) in microglial cells. Furthermore, treatment with the protein kinase A (PKA) inhibitor, H-89, blocked HO-1 induction by surfactin and abolished surfactin's suppressive effects on ROS and NO production. These results indicate that HO-1 and its upstream effector, PKA, play a pivotal role in the anti-neuroinflammatory response of surfactin in LTA-stimulated microglia. Therefore, surfactin might have therapeutic potential for neuroprotective agents to treat inflammatory and neurodegenerative diseases. - Highlights: ► Surfactin inhibits proinflammatory mediator synthesis in LTA-activated BV-2 cells. ► Surfactin suppresses NF-κB and STAT-1, but potentiates

  17. Involvement of PKA and HO-1 signaling in anti-inflammatory effects of surfactin in BV-2 microglial cells

    International Nuclear Information System (INIS)

    Park, Sun Young; Kim, Ji-Hee; Lee, Sang Joon; Kim, YoungHee

    2013-01-01

    Surfactin, one of the most powerful biosurfactants, is a bacterial cyclic lipopeptide. Here, we investigated the anti-neuroinflammatory properties of surfactin in lipoteichoic acid (LTA)-stimulated BV-2 microglial cells. Surfactin significantly inhibited excessive production of the pro-inflammatory mediators TNF-α, IL-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1), prostaglandin E 2 (PGE 2 ), nitric oxide (NO) and reactive oxygen species (ROS), and suppressed the expression of matrix metalloproteinase-9 (MMP-9), inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Subsequent mechanistic studies revealed that surfactin inhibited LTA-induced nuclear factor-kappaB (NF-κB) and signal transducer and activator of transcription-1 (STAT-1) activation. However, surfactin increases the phosphorylation of the STAT-3, a component of the homeostatic mechanism causing anti-inflammatory events. We also demonstrated that surfactin induces heme oxygenase-1 (HO-1) expression and nuclear factor-regulated factor-2 (Nrf-2) activation, and that the anti-inflammatory effects of surfactin are abrogated by small interfering RNA-mediated knock-down of HO-1 or Nrf-2. Interestingly, we found that surfactin increased the level of cAMP and induced phosphorylation of cAMP responsive element binding protein (CREB) in microglial cells. Furthermore, treatment with the protein kinase A (PKA) inhibitor, H-89, blocked HO-1 induction by surfactin and abolished surfactin's suppressive effects on ROS and NO production. These results indicate that HO-1 and its upstream effector, PKA, play a pivotal role in the anti-neuroinflammatory response of surfactin in LTA-stimulated microglia. Therefore, surfactin might have therapeutic potential for neuroprotective agents to treat inflammatory and neurodegenerative diseases. - Highlights: ► Surfactin inhibits proinflammatory mediator synthesis in LTA-activated BV-2 cells. ► Surfactin suppresses NF-κB and STAT-1, but potentiates phosphorylation

  18. WDR23 regulates NRF2 independently of KEAP1.

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    Jacqueline Y Lo

    2017-04-01

    Full Text Available Cellular adaptation to stress is essential to ensure organismal survival. NRF2/NFE2L2 is a key determinant of xenobiotic stress responses, and loss of negative regulation by the KEAP1-CUL3 proteasome system is implicated in several chemo- and radiation-resistant cancers. Advantageously using C. elegans alongside human cell culture models, we establish a new WDR23-DDB1-CUL4 regulatory axis for NRF2 activity that operates independently of the canonical KEAP1-CUL3 system. WDR23 binds the DIDLID sequence within the Neh2 domain of NRF2 to regulate its stability; this regulation is not dependent on the KEAP1-binding DLG or ETGE motifs. The C-terminal domain of WDR23 is highly conserved and involved in regulation of NRF2 by the DDB1-CUL4 complex. The addition of WDR23 increases cellular sensitivity to cytotoxic chemotherapeutic drugs and suppresses NRF2 in KEAP1-negative cancer cell lines. Together, our results identify WDR23 as an alternative regulator of NRF2 proteostasis and uncover a cellular pathway that regulates NRF2 activity and capacity for cytoprotection independently of KEAP1.

  19. Nrf2-Mediated Regulation of Skeletal Muscle Glycogen Metabolism

    Science.gov (United States)

    Yagishita, Yoko; Katsuoka, Fumiki; Kitajima, Yasuo; Nunomiya, Aki; Nagatomi, Ryoichi; Pi, Jingbo; Biswal, Shyam S.

    2016-01-01

    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 their SkM and then examined Nrf2 target gene expression in that tissue. In Keap1MuKO mice, blood glucose levels were significantly downregulated and the levels of the glycogen branching enzyme (Gbe1) and muscle-type PhKα subunit (Phka1) mRNAs, along with those of the glycogen branching enzyme (GBE) and the phosphorylase b kinase α subunit (PhKα) protein, were significantly upregulated in mouse SkM. Consistent with this result, chemical Nrf2 inducers promoted Gbe1 and Phka1 mRNA expression in both mouse SkM and C2C12 myotubes. Chromatin immunoprecipitation analysis demonstrated that Nrf2 binds the Gbe1 and Phka1 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 and PhKα expression and reduces muscle glycogen content, resulting in improved glucose tolerance. Our results also indicate that Nrf2 differentially regulates glycogen metabolism in SkM and the liver. PMID:27044864

  20. Enhanced B-Raf-mediated NRF2 gene transcription and HATs-mediated NRF2 protein acetylation contributes to ABCC1-mediated chemoresistance and glutathione-mediated survival in acquired topoisomerase II poison-resistant cancer cells.

    Science.gov (United States)

    Chen, Huang-Hui; Chang, Hsin-Huei; Chang, Jang-Yang; Tang, Ya-Chu; Cheng, Yung-Chi; Lin, Li-Mei; Cheng, Shu-Ying; Huang, Chih-Hsiang; Sun, Man-Wu; Chen, Chiung-Tong; Kuo, Ching-Chuan

    2017-12-01

    Nuclear factor erythroid-2-related factor 2 (NRF2) mainly regulates transcriptional activation through antioxidant-responsive elements (AREs) present in the promoters of NRF2 target genes. Recently, we found that NRF2 was overexpressed in a KB-derived drug-resistant cancer cell panel. In this panel, KB-7D cells, which show acquired resistance to topoisomerase II (Top II) poisons, exhibited the highest NRF2 activation. To investigate whether NRF2 directly contributed to acquired resistance against Top II poisons, we manipulated NRF2 by genetic and pharmacological approaches. The result demonstrated that silencing of NRF2 by RNA interference increased the sensitivity and treatment with NRF2 activator decreased the sensitivity of KB and KB-7D cells toward Top II poisons. Further, increased B-Raf-mediated NRF2 gene transcription and HATs-mediated NRF2 protein acetylation activated NRF2 signaling in KB-7D cells. Moreover, increased binding of NRF2 to an ARE in the promoter of ATP-binding cassette subfamily C member 1 (ABCC1) directly contributed to Top II poison resistance. In addition, activation of NRF2 increased glutathione level and antioxidant capacity in KB-7D cells compared with that in KB cells; moreover, high glutathione level provided survival advantage to KB-7D cells. Our study is the first to show that aberrant NRF2 activation is via increased B-Raf-mediated NRF2 gene transcription and HATs-mediated NRF2 protein acetylation, which increases the acquired resistance and promote the survival of Top II poison-resistant cancer cells. Importantly, NRF2 downstream effectors ABCC1 and glutathione directly contribute to acquired resistance and survival, respectively. These results suggest that blockade of NRF2 signaling may enhance therapeutic efficacy and reduce the survival of Top II poison-refractory tumors in clinical. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Elevation of HO-1 Expression Mitigates Intestinal Ischemia-Reperfusion Injury and Restores Tight Junction Function in a Rat Liver Transplantation Model

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    Xinjin Chi

    2015-01-01

    Full Text Available Aims. This study was aimed at investigating whether elevation of heme oxygenase-1 (HO-1 expression could lead to restoring intestinal tight junction (TJ function in a rat liver transplantation model. Methods. Intestinal mucosa injury was induced by orthotopic autologous liver transplantation (OALT on male Sprague-Dawley rats. Hemin (a potent HO-1 activator and zinc-protoporphyrin (ZnPP, a HO-1 competitive inhibitor, were separately administered in selected groups before OALT. The serum and intestinal mucosa samples were collected at 8 hours after the operation for analysis. Results. Hemin pretreatment significantly reduced the inflammation and oxidative stress in the mucosal tissue after OALT by elevating HO-1 protein expression, while ZnPP pretreatment aggravated the OALT mucosa injury. Meanwhile, the restriction on the expression of tight junction proteins zonula occludens-1 and occludin was removed after hemin pretreatment. These molecular events led to significant improvement on intestinal barrier function, which was proved to be through increasing nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2 and reducing nuclear translocation of nuclear factor kappa-B (NF-κB in intestinal injured mucosa. Summary. Our study demonstrated that elevation of HO-1 expression reduced the OALT-induced intestinal mucosa injury and TJ dysfunction. The HO-1 protective function was likely mediated through its effects of anti-inflammation and antioxidative stress.

  2. Elevation of HO-1 Expression Mitigates Intestinal Ischemia-Reperfusion Injury and Restores Tight Junction Function in a Rat Liver Transplantation Model

    Science.gov (United States)

    Chi, Xinjin; Yao, Weifeng; Xia, Hua; Jin, Yi; Li, Xi; Cai, Jun; Hei, Ziqing

    2015-01-01

    Aims. This study was aimed at investigating whether elevation of heme oxygenase-1 (HO-1) expression could lead to restoring intestinal tight junction (TJ) function in a rat liver transplantation model. Methods. Intestinal mucosa injury was induced by orthotopic autologous liver transplantation (OALT) on male Sprague-Dawley rats. Hemin (a potent HO-1 activator) and zinc-protoporphyrin (ZnPP, a HO-1 competitive inhibitor), were separately administered in selected groups before OALT. The serum and intestinal mucosa samples were collected at 8 hours after the operation for analysis. Results. Hemin pretreatment significantly reduced the inflammation and oxidative stress in the mucosal tissue after OALT by elevating HO-1 protein expression, while ZnPP pretreatment aggravated the OALT mucosa injury. Meanwhile, the restriction on the expression of tight junction proteins zonula occludens-1 and occludin was removed after hemin pretreatment. These molecular events led to significant improvement on intestinal barrier function, which was proved to be through increasing nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2) and reducing nuclear translocation of nuclear factor kappa-B (NF-κB) in intestinal injured mucosa. Summary. Our study demonstrated that elevation of HO-1 expression reduced the OALT-induced intestinal mucosa injury and TJ dysfunction. The HO-1 protective function was likely mediated through its effects of anti-inflammation and antioxidative stress. PMID:26064429

  3. Andrographolide induces Nrf2 and heme oxygenase 1 in astrocytes by activating p38 MAPK and ERK.

    Science.gov (United States)

    Wong, Siew Ying; Tan, Michelle G K; Wong, Peter T H; Herr, Deron R; Lai, Mitchell K P

    2016-09-23

    Andrographolide is the major labdane diterpenoid originally isolated from Andrographis paniculata and has been shown to have anti-inflammatory and antioxidative effects. However, there is a dearth of studies on the potential therapeutic utility of andrographolide in neuroinflammatory conditions. Here, we aimed to investigate the mechanisms underlying andrographolide's effect on the expression of anti-inflammatory and antioxidant heme oxygenase-1 (HO-1) in primary astrocytes. Measurements of the effects of andrograholide on antioxidant HO-1 and its transcription factor, Nrf2, include gene expression, protein turnover, and activation of putative signaling regulators. Andrographolide potently activated Nrf2 and also upregulated HO-1 expression in primary astrocytes. Andrographolide's effects on Nrf2 seemed to be biphasic, with acute (within 1 h) reductions in Nrf2 ubiquitination efficiency and turnover rate, followed by upregulation of Nrf2 mRNA between 8 and 24 h. The acute regulation of Nrf2 by andrographolide seemed to be independent of Keap1 and partly mediated by p38 MAPK and ERK signaling. These data provide further insights into the mechanisms underlying andrographolide's effects on astrocyte-mediated antioxidant, and anti-inflammatory responses and support the further assessment of andrographolide as a potential therapeutic for neurological conditions in which oxidative stress and neuroinflammation are implicated.

  4. Lutein Activates the Transcription Factor Nrf2 in Human Retinal Pigment Epithelial Cells.

    Science.gov (United States)

    Frede, Katja; Ebert, Franziska; Kipp, Anna P; Schwerdtle, Tanja; Baldermann, Susanne

    2017-07-26

    The degeneration of the retinal pigment epithelium caused by oxidative damage is a stage of development in age-related macular degeneration (AMD). The carotenoid lutein is a major macular pigment that may reduce the incidence and progression of AMD, but the underlying mechanism is currently not fully understood. Carotenoids are known to be direct antioxidants. However, carotenoids can also activate cellular pathways resulting in indirect antioxidant effects. Here, we investigate the influence of lutein on the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) target genes in human retinal pigment epithelial cells (ARPE-19 cells) using lutein-loaded Tween40 micelles. The micelles were identified as a suitable delivery system since they were nontoxic in APRE-19 cells up to 0.04% Tween40 and led to a cellular lutein accumulation of 62 μM ± 14 μM after 24 h. Lutein significantly enhanced Nrf2 translocation to the nucleus 1.5 ± 0.4-fold compared to that of unloaded micelles after 4 h. Furthermore, lutein treatment for 24 h significantly increased the transcripts of NAD(P)H:quinone oxidoreductase 1 (NQO1) by 1.7 ± 0.1-fold, glutamate-cysteine ligase regulatory subunit (GCLm) by 1.4 ± 0.1-fold, and heme oxygenase-1 (HO-1) by 1.8 ± 0.3-fold. Moreover, we observed a significant enhancement of NQO1 activity by 1.2 ± 0.1-fold. Collectively, this study indicates that lutein not only serves as a direct antioxidant but also activates Nrf2 in ARPE-19 cells.

  5. Linalool Inhibits LPS-Induced Inflammation in BV2 Microglia Cells by Activating Nrf2.

    Science.gov (United States)

    Li, Yang; Lv, Ou; Zhou, Fenggang; Li, Qingsong; Wu, Zhichao; Zheng, Yongri

    2015-07-01

    Linalool, a natural compound of the essential oils, has been reported to have anti-inflammatory effects. This study aimed to investigate the anti-inflammatory effects and mechanism of linalool in LPS-stimulated BV2 microglia cells. BV2 microglia cells were stimulated with LPS in the presence or absence of linalool. The production of inflammatory mediators TNF-α, IL-1β, NO, and PGE2 as well as Nrf2, HO-1 expression were detected. Our results showed that linalool inhibited LPS-induced TNF-α, IL-1β, NO, and PGE2 production in a dose-dependent manner. Linalool also inhibited LPS-induced NF-κB activation. Treatment of linalool induced nuclear translocation of Nrf2 and expression of HO-1. In addition, our results showed that the anti-inflammatory effect of linalool was attenuated by transfection with Nrf2 siRNA. In conclusion, these results suggested that linalool inhibits LPS-induced inflammation in BV2 microglia cells by activating Nrf2/HO-1 signaling pathway.

  6. Berberine activates Nrf2 nuclear translocation and inhibits apoptosis induced by high glucose in renal tubular epithelial cells through a phosphatidylinositol 3-kinase/Akt-dependent mechanism.

    Science.gov (United States)

    Zhang, Xiuli; Liang, Dan; Lian, Xu; Jiang, Yan; He, Hui; Liang, Wei; Zhao, Yue; Chi, Zhi-Hong

    2016-06-01

    Apoptosis of tubular epithelial cells is a major feature of diabetic kidney disease, and hyperglycemia triggers the generation of free radicals and oxidant stress in tubular cells. Berberine (BBR) is identified as a potential anti-diabetic herbal medicine due to its beneficial effects on insulin sensitivity, glucose metabolism and glycolysis. In this study, the underlying mechanisms involved in the protective effects of BBR on high glucose-induced apoptosis were explored using cultured renal tubular epithelial cells (NRK-52E cells) and human kidney proximal tubular cell line (HK-2 cells). We identified the pivotal role of phosphatidylinositol 3-kinase (PI3K)/Akt in BBR cellular defense mechanisms and revealed the novel effect of BBR on nuclear factor (erythroid-derived 2)-related factor-2 (Nrf2) and heme oxygenase (HO)-1 in NRK-52E and HK-2 cells. BBR attenuated reactive oxygen species production, antioxidant defense (GSH and SOD) and oxidant-sensitive proteins (Nrf2 and HO-1), which also were blocked by LY294002 (an inhibitor of PI3K) in HG-treated NRK-52E and HK-2 cells. Furthermore, BBR improved mitochondrial function by increasing mitochondrial membrane potential. BBR-induced anti-apoptotic function was demonstrated by decreasing apoptotic proteins (cytochrome c, Bax, caspase3 and caspase9). All these findings suggest that BBR exerts the anti-apoptosis effects through activation of PI3K/Akt signal pathways and leads to activation of Nrf2 and induction of Nrf2 target genes, and consequently protecting the renal tubular epithelial cells from HG-induced apoptosis.

  7. The Keap1-Nrf2 system in cancers: Stress response and anabolic metabolism

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    Yoichiro eMitsuishi

    2012-12-01

    Full Text Available The Keap1-Nrf2 pathway plays a central role in the protection of cells against oxidative and xenobiotic stresses. Nrf2 is a potent transcription activator that recognizes a unique DNA sequence known as the antioxidant response element (ARE. Under normal conditions, Nrf2 binds to Keap1 in the cytoplasm, resulting in proteasomal degradation. Following exposure to electrophiles or reactive oxygen species, Nrf2 becomes stabilized, translocates into the nucleus and activates the transcription of various cytoprotective genes. Increasing attention has been paid to the role of Nrf2 in cancer cells because the constitutive stabilization of Nrf2 has been observed in many human cancers with poor prognosis. Recent studies have shown that the antioxidant and detoxification activities of Nrf2 confer chemo- and radio-resistance to cancer cells. In this review, we provide an overview of the Keap1-Nrf2 system and discuss its role under physiological and pathological conditions, including cancers. We also introduce the results of our recent study describing Nrf2 function in the metabolism of cancer cells. Nrf2 likely confers a growth advantage to cancer cells through enhancing cytoprotection and anabolism. Finally, we discuss the possible impact of Nrf2 inhibitors on cancer therapy.

  8. Novel Hematopoietic Target Genes in the NRF2-Mediated Transcriptional Pathway

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    Michelle R. Campbell

    2013-01-01

    Full Text Available Nuclear factor- (erythroid-derived 2 like 2 (NFE2L2, NRF2 is a key transcriptional activator of the antioxidant response pathway and is closely related to erythroid transcription factor NFE2. Under oxidative stress, NRF2 heterodimerizes with small Maf proteins and binds cis-acting enhancer sequences found near oxidative stress response genes. Using the dietary isothiocyanate sulforaphane (SFN to activate NRF2, chromatin immunoprecipitation sequencing (ChIP-seq identified several hundred novel NRF2-mediated targets beyond its role in oxidative stress. Activated NRF2 bound the antioxidant response element (ARE in promoters of several known and novel target genes involved in iron homeostasis and heme metabolism, including known targets FTL and FTH1, as well as novel binding in the globin locus control region. Five novel NRF2 target genes were chosen for followup: AMBP, ABCB6, FECH, HRG-1 (SLC48A1, and TBXAS1. SFN-induced gene expression in erythroid K562 and lymphoid cells were compared for each target gene. NRF2 silencing showed reduced expression in lymphoid, lung, and hepatic cells. Furthermore, stable knockdown of NRF2 negative regulator KEAP1 in K562 cells resulted in increased NQO1, AMBP, and TBXAS1 expression. NFE2 binding sites in K562 cells revealed similar binding profiles as lymphoid NRF2 sites in all potential NRF2 candidates supporting a role for NRF2 in heme metabolism and erythropoiesis.

  9. Acupuncture ameliorates cognitive impairment and hippocampus neuronal loss in experimental vascular dementia through Nrf2-mediated antioxidant response.

    Science.gov (United States)

    Wang, Xue-Rui; Shi, Guang-Xia; Yang, Jing-Wen; Yan, Chao-Qun; Lin, Li-Ting; Du, Si-Qi; Zhu, Wen; He, Tian; Zeng, Xiang-Hong; Xu, Qian; Liu, Cun-Zhi

    2015-12-01

    Emerging evidence suggests acupuncture could exert neuroprotection in the vascular dementia via anti-oxidative effects. However, the involvement of Nrf2, a master regulator of antioxidant defense, in acupuncture-induced neuroprotection in vascular dementia remains undetermined. The goal of our study was to investigate the contribution of Nrf2 in acupuncture and its effects on vascular dementia. Morris water maze and Nissl staining were used to assess the effect of acupuncture on cognitive function and hippocampal neurodegeneration in experimental vascular dementia. The distribution of Nrf2 in neurons in hippocampus, the protein expression of Nrf2 in both cytosol and nucleus, and the protein and mRNA levels of its downstream target genes NQO1 and HO-1 were detected by double immunofluorescent staining, Western blotting and realtime PCR analysis respectively. Cognitive function and microglia activation were measured in both wild-type and Nrf2 gene knockout mice after acupuncture treatment. We found that acupuncture could remarkably reverse the cognitive deficits, neuron cell loss, reactive oxygen species production, and decreased cerebral blood flow. It was notable that acupuncture enhanced nuclear translocation of Nrf2 in neurons and up-regulate the protein and mRNA levels of Nrf2 and its target genes HO-1 and NQO1. Moreover, acupuncture could significantly down-regulated the over-activation of microglia after common carotid artery occlusion surgery. However, the reversed cognitive deficits, neuron cell loss and microglia activation by acupuncture were abolished in Nrf2 gene knockout mice. In conclusion, these findings provide evidence that the neuroprotection of acupuncture in models of vascular dementia was via the Nrf2 activation and Nrf2-dependent microglia activation. Copyright © 2015. Published by Elsevier Inc.

  10. Induction of activation of the antioxidant response element and stabilization of Nrf2 by 3-(3-pyridylmethylidene)-2-indolinone (PMID) confers protection against oxidative stress-induced cell death

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    Yao, Jia-Wei [Tianjin University, School of Chemical Engineering and Technology, Department of pharmaceutical engineering, Tianjin 300072 (China); Beijing Institute of Radiation Medicine, Beijing 100850 (China); Liu, Jing [Beijing Institute of Radiation Medicine, Beijing 100850 (China); Kong, Xiang-Zhen [Tianjin University, School of Chemical Engineering and Technology, Department of pharmaceutical engineering, Tianjin 300072 (China); Beijing Institute of Radiation Medicine, Beijing 100850 (China); Zhang, Shou-Guo [Beijing Institute of Radiation Medicine, Beijing 100850 (China); Wang, Xiao-Hui [Beijing Institute of Radiation Medicine, Beijing 100850 (China); State Key laboratory of Proteomics, Beijing 100850 (China); Yu, Miao; Zhan, Yi-Qun; Li, Wei; Xu, Wang-Xiang [Beijing Institute of Radiation Medicine, Beijing 100850 (China); Tang, Liu-Jun [Beijing Institute of Radiation Medicine, Beijing 100850 (China); State Key laboratory of Proteomics, Beijing 100850 (China); Ge, Chang-Hui [Beijing Institute of Radiation Medicine, Beijing 100850 (China); Wang, Lin, E-mail: wanlin07@sina.com [Beijing Institute of Radiation Medicine, Beijing 100850 (China); Li, Chang-Yan, E-mail: happylichy@yahoo.com.cn [Beijing Institute of Radiation Medicine, Beijing 100850 (China); State Key laboratory of Proteomics, Beijing 100850 (China); Yang, Xiao-Ming, E-mail: xmyang2@nic.bmi.ac.cn [Tianjin University, School of Chemical Engineering and Technology, Department of pharmaceutical engineering, Tianjin 300072 (China); Beijing Institute of Radiation Medicine, Beijing 100850 (China); State Key laboratory of Proteomics, Beijing 100850 (China)

    2012-03-01

    The antioxidant response elements (ARE) are a cis-acting enhancer sequence located in regulatory regions of antioxidant and detoxifying genes. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a member of the Cap ‘n’ Collar family of transcription factors that binds to the ARE and regulates the transcription of specific ARE-containing genes. Under oxidative stress, Nrf2/ARE induction is fundamental to defense against reactive oxygen species (ROS) and serves as a key factor in the protection against toxic xenobiotics. 3-(3-Pyridylmethylidene)-2-Indolinone (PMID) is a derivative of 2-indolinone compounds which act as protein kinase inhibitors and show anti-tumor activity. However, the role of PMID in the oxidative stress remains unknown. In the present study, we showed that PMID induced the activation of ARE-mediated transcription, increased the DNA-binding activity of Nrf2 and then up-regulated the expression of antioxidant genes such as HO-1, SOD, and NQO1. The level of Nrf2 protein was increased in cells treated with PMID by a post-transcriptional mechanism. Under CHX treatment, the stability of Nrf2 protein was enhanced by PMID with decreased turnover rate. We showed that PMID reduced the ubiquitination of Nrf2 and disrupted the Cullin3 (Cul3)-Keap1 interaction. Furthermore, cells treated with PMID showed resistance to cytotoxicity by H{sub 2}O{sub 2} and pro-oxidant 6-OHDA. PMID also up-regulated the antioxidant level in BALB/c mice. Taken together, the compound PMID induces the ARE-mediated gene expression through stabilization of Nrf2 protein and activation of Nrf2/ARE pathway and protects against oxidative stress-mediated cell death. -- Highlights: ► PMID up-regulates ARE-mediated antioxidant gene expression in vitro and in vivo. ► PMID enhances the stabilization of Nrf2 protein, decreasing Nrf2 turnover rate. ► PMID disrupted the Cullin3 (Cul3)-Keap1 interaction. ► PMID protects against cell death induced by H{sub 2}O{sub 2} and pro-oxidant 6

  11. A possible involvement of Nrf2-mediated heme oxygenase-1 up-regulation in protective effect of the proton pump inhibitor pantoprazole against indomethacin-induced gastric damage in rats

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    Lee Ho-Jae

    2012-10-01

    Full Text Available Abstract Background Proton pump is an integral membrane protein that is ubiquitous ATP binding cassette (ABC involved in many transport processes in all living organisms, among which a specialized form of pump, so called p-type proton pump, exists in the parietal cells of stomach. Though proton pump inhibitors (PPIs are frequently prescribed to prevent nonsteroidal anti-inflammatory drugs (NSAIDs-induced gastric damage, the acid suppressive actions do not suffice to explain. Methods In order to document the effects of pantoprazole, one of PPIs, on the NSAIDs-induced gastric damage, in vitro and in vivo studies were performed. Immunocytochemistry, Western blot analysis, electrophoretic mobility shift assay and RT-PCR were conducted to evaluate the induction of heme oxygenase-1 (HO-1 through Nrf2 activation in normal gastric mucosal RGM-1 cells or in vivo stomach tissues from rats treated with indomethacin and/or pantoprazole. Results Pantoprazole activated Nrf2 through inactivation of Keap1, after which the expression of HO-1 was significantly increased in a dose-dependent manner in RGM-1 cells. Increased ARE-DNA binding activity was observed maximally at 1 h with 300 μM of pantoprazole. The expression of HO-1 induced by pantoprazole was significantly associated with the increased in vitro tube formation (P P In vivo model of indomethacin-induced gastric damage could validate in vitro-drawn results that pantoprazole remarkably protected against indomethacin-induced gastric damage, in which zinc protoporphyrin (5 mg/kg, ip significantly abolished the protective efficacy of pantoprazole. Conclusion These results demonstrate that Nrf2-mediated HO-1 induction of PPIs afforded a significant protective effect against NSAIDs-induced gastric damage beyond acid suppressive actions.

  12. Oxidative Stress Responses and NRF2 in Human Leukaemia

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    Amina Abdul-Aziz

    2015-01-01

    Full Text Available Oxidative stress as a result of elevated levels of reactive oxygen species (ROS has been observed in almost all cancers, including leukaemia, where they contribute to disease development and progression. However, cancer cells also express increased levels of antioxidant proteins which detoxify ROS. This includes glutathione, the major antioxidant in human cells, which has recently been identified to have dysregulated metabolism in human leukaemia. This suggests that critical balance of intracellular ROS levels is required for cancer cell function, growth, and survival. Nuclear factor (erythroid-derived 2-like 2 (NRF2 transcription factor plays a dual role in cancer. Primarily, NRF2 is a transcription factor functioning to protect nonmalignant cells from malignant transformation and oxidative stress through transcriptional activation of detoxifying and antioxidant enzymes. However, once malignant transformation has occurred within a cell, NRF2 functions to protect the tumour from oxidative stress and chemotherapy-induced cytotoxicity. Moreover, inhibition of the NRF2 oxidative stress pathway in leukaemia cells renders them more sensitive to cytotoxic chemotherapy. Our improved understanding of NRF2 biology in human leukaemia may permit mechanisms by which we could potentially improve future cancer therapies. This review highlights the mechanisms by which leukaemic cells exploit the NRF2/ROS response to promote their growth and survival.

  13. Hawthorn (Crataegus oxyacantha L.) bark extract regulates antioxidant response element (ARE)-mediated enzyme expression via Nrf2 pathway activation in normal hepatocyte cell line.

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    Krajka-Kuźniak, Violetta; Paluszczak, Jarosław; Oszmiański, Jan; Baer-Dubowska, Wanda

    2014-04-01

    Hawthorn (Crataegus oxyacantha L.), a plant used in traditional medicine, is a rich source of procyanidins which have been reported to exhibit antioxidant and anti-carcinogenic activity. In this study, we assessed the effect of hawthorn bark extract (HBE) on Nrf2 pathway activation in THLE-2 and HepG2 cells. Treatment with 1.1 µg/mL, 5.5 µg/mL and 11 µg/mL of HBE resulted in the translocation of Nrf2 from the cytosol to the nucleus in both cell lines; however, the accumulation of phosphorylated Nrf2 was observed only in THLE-2. Accordingly, treatment of cells with HBE was associated with an increase in the mRNA and protein level of such Nrf2-dependent genes as glutathione S-transferases (GSTA, GSTP, GSTM, GSTT), NAD(P)H:quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (HO-1) (0.2-1.1-fold change, p < 0.05), however, only in normal THLE-2 hepatocytes. The induction of NQO1 correlated with an increased level of p53 (0.21-0.42-fold change, p < 0.05). These effects may be related to induction of phosphorylation of upstream ERK and JNK kinases. Collectively, the results suggest that the Nrf2/ARE pathway may play an important role in the regulation of procyanidin-mediated antioxidant/detoxifying effects in hepatocytes, and this may explain the hepatoprotective and chemopreventive properties of these phytochemicals. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Nrf2-dependent induction of innate host defense via heme oxygenase-1 inhibits Zika virus replication

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    Huang, Hanxia; Falgout, Barry; Takeda, Kazuyo; Yamada, Kenneth M.; Dhawan, Subhash

    2017-01-01

    We identified primary human monocyte-derived macrophages (MDM) as vulnerable target cells for Zika virus (ZIKV) infection. We demonstrate dramatic effects of hemin, the natural inducer of the heme catabolic enzyme heme oxygenase-1 (HO-1), in the reduction of ZIKV replication in vitro. Both LLC-MK2 monkey kidney cells and primary MDM exhibited hemin-induced HO-1 expression with major reductions of > 90% in ZIKV replication, with little toxicity to infected cells. Silencing expression of HO-1 or its upstream regulatory gene, nuclear factor erythroid-related factor 2 (Nrf2), attenuated hemin-induced suppression of ZIKV infection, suggesting an important role for induction of these intracellular mediators in retarding ZIKV replication. The inverse correlation between hemin-induced HO-1 levels and ZIKV replication provides a potentially useful therapeutic modality based on stimulation of an innate cellular response against Zika virus infection. PMID:28068513

  15. Inhibition of neuroinflammation in BV2 microglia by the biflavonoid kolaviron is dependent on the Nrf2/ARE antioxidant protective mechanism.

    Science.gov (United States)

    Onasanwo, Samuel A; Velagapudi, Ravikanth; El-Bakoush, Abdelmeneim; Olajide, Olumayokun A

    2016-03-01

    Kolaviron is a mixture of biflavonoids found in the nut of the West African edible seed Garcinia kola, and it has been reported to exhibit a wide range of pharmacological activities. In this study, we investigated the effects of kolaviron in neuroinflammation. The effects of kolaviron on the expression of nitric oxide/inducible nitric oxide synthase (iNOS), prostaglandin E2 (PGE2)/cyclooxygenase-2, cellular reactive oxygen species (ROS) and the pro-inflammatory cytokines were examined in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Molecular mechanisms of the effects of kolaviron on NF-κB and Nrf2/ARE signalling pathways were analysed by immunoblotting, binding assays and reporter assays. RNA interference was used to investigate the role of Nrf2 in the anti-inflammatory effect of kolaviron. Neuroprotective effect of kolaviron was assessed in a BV2 microglia/HT22 hippocampal neuron co-culture. Kolaviron inhibited the protein levels of NO/iNOS, PGE2/COX-2, cellular ROS and the pro-inflammatory cytokines (TNFα and IL-6) in LPS-stimulated microglia. Further mechanistic studies showed that kolaviron inhibited neuroinflammation by inhibiting IκB/NF-κB signalling pathway in LPS-activated BV2 microglia. Kolaviron produced antioxidant effect in BV2 microglia by increasing HO-1 via the Nrf2/antioxidant response element pathway. RNAi experiments revealed that Nrf2 is needed for the anti-inflammatory effects of kolaviron. Kolaviron protected HT22 neurons from neuroinflammation-induced toxicity. Kolaviron inhibits neuroinflammation through Nrf2-dependent mechanisms. This compound may therefore be beneficial in neuroinflammation-related neurodegenerative disorders.

  16. The Cytoprotective Effects of E-α-(4-Methoxyphenyl-2',3,4,4'-Tetramethoxychalcone (E-α-p-OMe-C6H4-TMC--A Novel and Non-Cytotoxic HO-1 Inducer.

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    Kai B Kaufmann

    Full Text Available Cell protection against different noxious stimuli like oxidative stress or chemical toxins plays a central role in the treatment of many diseases. The inducible heme oxygenase isoform, heme oxygenase-1 (HO-1, is known to protect cells against a variety of harmful conditions including apoptosis. Because a number of medium strong electrophiles from a series of α-X-substituted 2',3,4,4'-tetramethoxychalcones (α-X-TMCs, X = H, F, Cl, Br, I, CN, Me, p-NO2-C6H4, Ph, p-OMe-C6H4, NO2, CF3, COOEt, COOH had proven to activate Nrf2 resulting in HO-1 induction and inhibit NF-κB downstream target genes, their protective effect against staurosporine induced apoptosis and reactive oxygen species (ROS production was investigated. RAW264.7 macrophages treated with 19 different chalcones (15 α-X-TMCs, chalcone, 2'-hydroxychalcone, calythropsin and 2'-hydroxy-3,4,4'-trimethoxychalcone prior to staurosporine treatment were analyzed for apoptosis and ROS production, as well as HO-1 protein expression and enzyme activity. Additionally, Nrf2 and NF-κB activity was assessed. We found that amongst all tested chalcones only E-α-(4-methoxyphenyl-2',3,4,4'-tetramethoxychalcone (E-α-p-OMe-C6H4-TMC demonstrated a distinct, statistically significant antiapoptotic effect in a dose dependent manner, showing no toxic effects, while its double bond isomer Z-α-p-OMe-C6H4-TMC displayed no significant activity. Also, E-α-p-OMe-C6H4-TMC induced HO-1 protein expression and increased HO-1 activity, whilst inhibition of HO-1 by SnPP-IX abolished its antiapoptotic effect. The only weakly electrophilic chalcone E-α-p-OMe-C6H4-TMC reduced the staurosporine triggered formation of ROS, while inducing the translocation of Nrf2 into the nucleus. Furthermore, staurosporine induced NF-κB activity was attenuated following E-α-p-OMe-C6H4-TMC treatment. Overall, E-α-p-OMe-C6H4-TMC demonstrated its effective cytoprotective potential via a non-toxic induction of HO-1 in RAW264

  17. The Cytoprotective Effects of E-α-(4-Methoxyphenyl)-2’,3,4,4'-Tetramethoxychalcone (E-α-p-OMe-C6H4-TMC)—A Novel and Non-Cytotoxic HO-1 Inducer

    Science.gov (United States)

    Kaufmann, Kai B.; Al-Rifai, Nafisah; Ulbrich, Felix; Schallner, Nils; Rücker, Hannelore; Enzinger, Monika; Petkes, Hermina; Pitzl, Sebastian

    2015-01-01

    Cell protection against different noxious stimuli like oxidative stress or chemical toxins plays a central role in the treatment of many diseases. The inducible heme oxygenase isoform, heme oxygenase-1 (HO-1), is known to protect cells against a variety of harmful conditions including apoptosis. Because a number of medium strong electrophiles from a series of α-X-substituted 2’,3,4,4’-tetramethoxychalcones (α-X-TMCs, X = H, F, Cl, Br, I, CN, Me, p-NO2-C6H4, Ph, p-OMe-C6H4, NO2, CF3, COOEt, COOH) had proven to activate Nrf2 resulting in HO-1 induction and inhibit NF-κB downstream target genes, their protective effect against staurosporine induced apoptosis and reactive oxygen species (ROS) production was investigated. RAW264.7 macrophages treated with 19 different chalcones (15 α-X-TMCs, chalcone, 2’-hydroxychalcone, calythropsin and 2’-hydroxy-3,4,4’-trimethoxychalcone) prior to staurosporine treatment were analyzed for apoptosis and ROS production, as well as HO-1 protein expression and enzyme activity. Additionally, Nrf2 and NF-κB activity was assessed. We found that amongst all tested chalcones only E-α-(4-methoxyphenyl)-2’,3,4,4'-tetramethoxychalcone (E-α-p-OMe-C6H4-TMC) demonstrated a distinct, statistically significant antiapoptotic effect in a dose dependent manner, showing no toxic effects, while its double bond isomer Z-α-p-OMe-C6H4-TMC displayed no significant activity. Also, E-α-p-OMe-C6H4-TMC induced HO-1 protein expression and increased HO-1 activity, whilst inhibition of HO-1 by SnPP-IX abolished its antiapoptotic effect. The only weakly electrophilic chalcone E-α-p-OMe-C6H4-TMC reduced the staurosporine triggered formation of ROS, while inducing the translocation of Nrf2 into the nucleus. Furthermore, staurosporine induced NF-κB activity was attenuated following E-α-p-OMe-C6H4-TMC treatment. Overall, E-α-p-OMe-C6H4-TMC demonstrated its effective cytoprotective potential via a non-toxic induction of HO-1 in RAW264

  18. Escin activates AKT-Nrf2 signaling to protect retinal pigment epithelium cells from oxidative stress.

    Science.gov (United States)

    Wang, Kaijun; Jiang, Yiqian; Wang, Wei; Ma, Jian; Chen, Min

    2015-12-25

    Here we explored the anti-oxidative and cytoprotective potentials of escin, a natural triterpene-saponin, against hydrogen peroxide (H2O2) in retinal pigment epithelium (RPE) cells. We showed that escin remarkably attenuated H2O2-induced death and apoptosis of established (ARPE-19) and primary murine RPE cells. Meanwhile, ROS production and lipid peroxidation by H2O2 were remarkably inhibited by escin. Escin treatment in RPE cells resulted in NF-E2-related factor 2 (Nrf2) signaling activation, evidenced by transcription of anti-oxidant-responsive element (ARE)-regulated genes, including HO-1, NQO-1 and SRXN-1. Knockdown of Nrf2 through targeted shRNAs/siRNAs alleviated escin-mediated ARE gene transcription, and almost abolished escin-mediated anti-oxidant activity and RPE cytoprotection against H2O2. Reversely, escin was more potent against H2O2 damages in Nrf2-over-expressed ARPE-19 cells. Further studies showed that escin-induced Nrf2 activation in RPE cells required AKT signaling. AKT inhibitors (LY294002 and perifosine) blocked escin-induced AKT activation, and dramatically inhibited Nrf2 phosphorylation, its cytosol accumulation and nuclear translocation in RPE cells. Escin-induced RPE cytoprotection against H2O2 was also alleviated by the AKT inhibitors. Together, these results demonstrate that escin protects RPE cells from oxidative stress possibly through activating AKT-Nrf2 signaling. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Nrf2 signaling contributes to the neuroprotective effects of urate against 6-OHDA toxicity.

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    Ning Zhang

    Full Text Available BACKGROUND: Mounting evidence shows that urate may become a biomarker of Parkinson's disease (PD diagnosis and prognosis and a neuroprotectant candidate for PD therapy. However, the cellular and molecular mechanisms underlying its neuroprotective actions remain poorly understood. RESULTS: In this study, we showed that urate pretreatment protected dopaminergic cell line (SH-SY5Y and MES23.5 against 6-hydroxydopamine (6-OHDA- and hydrogen peroxide- induced cell damage. Urate was found to be accumulated into SH-SY5Y cells after 30 min treatment. Moreover, urate induced NF-E2-related factor 2 (Nrf2 accumulation by inhibiting its ubiquitinationa and degradation, and also promoted its nuclear translocation; however, it did not modulate Nrf2 mRNA level or Kelch-like ECH-associated protein 1 (Keap1 expression. In addition, urate markedly up-regulated the transcription and protein expression of γ-glutamate-cysteine ligase catalytic subunit (γ-GCLC and heme oxygenase-1 (HO-1, both of which are controlled by Nrf2 activity. Furthermore, Nrf2 knockdown by siRNA abolished the intracellular glutathione augmentation and the protection exerted by urate pretreatment. CONCLUSION: Our findings demonstrated that urate treatment may result in Nrf2-targeted anti-oxidant genes transcription and expression by reducing Nrf2 ubiquitination and degradation and promoting its nuclear translocation, and thus offer neuroprotection on dopaminergic cells against oxidative stresses.

  20. Sulforaphane reverses glucocorticoid-induced apoptosis in osteoblastic cells through regulation of the Nrf2 pathway

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    Lin H

    2014-07-01

    Full Text Available Hao Lin,1,* Bo Wei,1,* Guangsheng Li,1 Jinchang Zheng,1 Jiecong Sun,1 Jiaqi Chu,2 Rong Zeng,1 Yanru Niu21Department of Spinal Surgery, Affiliated Hospital of Guangdong Medical College, Zhanjiang, People’s Republic of China; 2Laboratory Institute of Minimally Invasive Orthopedic Surgery, Affiliated Hospital of Guangdong Medical College, Zhanjiang, People’s Republic of China *These authors contributed equally to this work Abstract: Apoptosis of osteoblasts triggered by high-dose glucocorticoids (GCs has been identified as a major cause of osteoporosis. However, the underlying molecular mechanisms accounting for this action remain elusive, which has impeded the prevention and cure of this side effect. Sulforaphane (SFP is a naturally occurring isothiocyanate that has huge health benefits for humans. In this study, by using osteoblastic MC3T3-E1 cells as a model, we demonstrate the protective effects of SFP against dexamethasone (Dex-induced apoptosis and elucidate the underlying molecular mechanisms. The results show that SFP could effectively inhibit the Dex-induced growth inhibition and release of lactate dehydrogenase in MC3T3-E1 cells. Treatment with Dex induced caspase-dependent apoptosis in MC3T3-E1 cells, as evidenced by an increase in the Sub-G1 phase, chromatin condensation, and deoxyribonucleic acid fragmentation, which were significantly suppressed by coincubation with SFP. Mitochondria-mediated apoptosis pathway contributed importantly to Dex-induced apoptosis, as revealed by the activation of caspase-3/-9 and subsequent cleavage of poly adenosine diphosphate ribose polymerase, which was also effectively blocked by SFP. Moreover, treatments of Dex strongly induced overproduction of reactive oxygen species and inhibited the expression of nuclear factor erythroid 2-related factor 2 (Nrf2 and the downstream effectors HO1 and NQO1. However, cotreatment with SFP effectively reversed this action of Dex. Furthermore, silencing of Nrf2 by

  1. Nrf2 deficiency improves glucose tolerance in mice fed a high-fat diet

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    Zhang, Yu-Kun Jennifer; Wu, Kai Connie; Liu, Jie; Klaassen, Curtis D., E-mail: cklaasse@kumc.edu

    2012-11-01

    Nrf2, a master regulator of intracellular redox homeostasis, is indicated to participate in fatty acid metabolism in liver. However, its role in diet-induced obesity remains controversial. In the current study, genetically engineered Nrf2-null, wild-type (WT), and Nrf2-activated, Keap1-knockdown (K1-KD) mice were fed either a control or a high-fat Western diet (HFD) for 12 weeks. The results indicate that the absence or enhancement of Nrf2 activity did not prevent diet-induced obesity, had limited effects on lipid metabolism, but affected blood glucose homeostasis. Whereas the Nrf2-null mice were resistant to HFD-induced glucose intolerance, the Nrf2-activated K1-KD mice exhibited prolonged elevation of circulating glucose during a glucose tolerance test even on the control diet. Feeding a HFD did not activate the Nrf2 signaling pathway in mouse livers. Fibroblast growth factor 21 (Fgf21) is a liver-derived anti-diabetic hormone that exerts glucose- and lipid-lowering effects. Fgf21 mRNA and protein were both elevated in livers of Nrf2-null mice, and Fgf21 protein was lower in K1-KD mice than WT mice. The inverse correlation between Nrf2 activity and hepatic expression of Fgf21 might explain the improved glucose tolerance in Nrf2-null mice. Furthermore, a more oxidative cellular environment in Nrf2-null mice could affect insulin signaling in liver. For example, mRNA of insulin-like growth factor binding protein 1, a gene repressed by insulin in hepatocytes, was markedly elevated in livers of Nrf2-null mice. In conclusion, genetic alteration of Nrf2 does not prevent diet-induced obesity in mice, but deficiency of Nrf2 improves glucose homeostasis, possibly through its effects on Fgf21 and/or insulin signaling. -- Highlights: ► Nrf2 deficiency improves glucose tolerance in mice fed a high-fat diet. ► The anti-diabetic hormone, Fgf21, is highly expressed in livers of Nrf2-null mice. ► The absence of Nrf2 increases the insulin-regulated Igfbp-1 mRNA in liver.

  2. Nrf2 deficiency improves glucose tolerance in mice fed a high-fat diet

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    Zhang, Yu-Kun Jennifer; Wu, Kai Connie; Liu, Jie; Klaassen, Curtis D.

    2012-01-01

    Nrf2, a master regulator of intracellular redox homeostasis, is indicated to participate in fatty acid metabolism in liver. However, its role in diet-induced obesity remains controversial. In the current study, genetically engineered Nrf2-null, wild-type (WT), and Nrf2-activated, Keap1-knockdown (K1-KD) mice were fed either a control or a high-fat Western diet (HFD) for 12 weeks. The results indicate that the absence or enhancement of Nrf2 activity did not prevent diet-induced obesity, had limited effects on lipid metabolism, but affected blood glucose homeostasis. Whereas the Nrf2-null mice were resistant to HFD-induced glucose intolerance, the Nrf2-activated K1-KD mice exhibited prolonged elevation of circulating glucose during a glucose tolerance test even on the control diet. Feeding a HFD did not activate the Nrf2 signaling pathway in mouse livers. Fibroblast growth factor 21 (Fgf21) is a liver-derived anti-diabetic hormone that exerts glucose- and lipid-lowering effects. Fgf21 mRNA and protein were both elevated in livers of Nrf2-null mice, and Fgf21 protein was lower in K1-KD mice than WT mice. The inverse correlation between Nrf2 activity and hepatic expression of Fgf21 might explain the improved glucose tolerance in Nrf2-null mice. Furthermore, a more oxidative cellular environment in Nrf2-null mice could affect insulin signaling in liver. For example, mRNA of insulin-like growth factor binding protein 1, a gene repressed by insulin in hepatocytes, was markedly elevated in livers of Nrf2-null mice. In conclusion, genetic alteration of Nrf2 does not prevent diet-induced obesity in mice, but deficiency of Nrf2 improves glucose homeostasis, possibly through its effects on Fgf21 and/or insulin signaling. -- Highlights: ► Nrf2 deficiency improves glucose tolerance in mice fed a high-fat diet. ► The anti-diabetic hormone, Fgf21, is highly expressed in livers of Nrf2-null mice. ► The absence of Nrf2 increases the insulin-regulated Igfbp-1 mRNA in liver.

  3. Genetic activation of Nrf2 protects against fasting-induced oxidative stress in livers of mice.

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    Yu-Kun Jennifer Zhang

    Full Text Available Acute fasting causes elevated oxidative stress. The current study investigated the effects of the nuclear factor erythoid 2-related factor 2 (Nrf2, the sensor of oxidative stress in cells, on energy homeostasis and liver pathophysiology during fasting. Feed was removed from mice possessing none (Nrf2-null, normal (wild-type, WT, enhanced (Keap1-knockdown, K1-KD, and maximum (hepatocyte-specific Keap1-knockout, K1-HKO Nrf2 activity in liver for 24 h. Body weight, blood glucose, and blood lipid profiles were similar among mice with graded Nrf2 activity under either fed or fasted conditions. Fasting reduced liver size in mice expressing Nrf2, but not in Nrf2-null mice. Nrf2-null mice accumulated more non-esterified free fatty acids and triglycerides in liver after fasting than the other genotypes of mice. Fatty acids are mainly catabolized in mitochondria, and Nrf2-null mice had lower mitochondrial content in liver under control feeding conditions, which was further reduced by fasting. In contrast, mitochondrial contents in mice with enhanced Nrf2 activity were not affected by fasting. Oxidative stress, determined by staining of free radicals and quantification of malondialdehyde equivalents, was highest in Nrf2-null and lowest in K1-HKO mice after fasting. The exacerbated oxidative stress in livers of Nrf2-null mice is predicted to lead to damages to mitochondria, and therefore diminished oxidation and increased accumulation of lipids in livers of Nrf2-null mice. In summary, the Nrf2-regulated signaling pathway is critical in protecting mitochondria from oxidative stress during feed deprivation, which ensures efficient utilization of fatty acids in livers of mice.

  4. Differential expression patterns of Nqo1, AKR1B8 and Ho-1 in the liver and small intestine of C57BL/6 mice treated with sulforaphane

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    Lin Luo

    2015-12-01

    Full Text Available This data article contains complementary figures and results related to the research article entitled “butylated hydroxyanisole induces distinct expression patterns of Nrf2 and detoxification enzymes in the liver and small intestine of C57BL/6 mice” (Luo et al., 2015 [1], which defined the basal and butylated hydroxyanisole (BHA-induced expression patterns of Phase II enzymes Nqo1, AKR1B8, and Ho-1 in the liver and small intestine of C57BL/6 mice. Sulforaphane [1-isothiocyanato-4-(methylsulfinylbutane] (SFN, a naturally occurring isothiocyanate derived from cruciferous vegetables, is a highly potent inducer of phase II cytoprotective enzymes. This dataset reports the histological changes of Nqo1, AKR1B8, and Ho-1 in wild-type (WT and Nrf2-/- mice induced by SFN. The mice were given a 25 mg/kg single oral dose of SFN for 24 h and 48 h. Immunohistochemistry revealed that, in the liver from WT mice, SFN increased Nqo1 staining in hepatocytes with slight higher staining in the pericentral region. The induction of AKR1B8 appeared mostly in hepatocytes in the periportal region. The basal and inducible Ho-1 was located predominately in Kupffer cells. In the small intestine from WT mice, the inducible expression of Nqo1 and AKR1B8 appeared more obvious in the villus than that in the crypt.

  5. Novel compound from Polygonum multiflorum inhibits inflammatory response in LPS-stimulated microglia by upregulating AMPK/Nrf2 pathways.

    Science.gov (United States)

    Park, Sun Young; Jin, Mei Ling; Chae, Seon Yeong; Ko, Min Jung; Choi, Yung Hyun; Park, Geuntae; Choi, Young-Whan

    2016-11-01

    Polygonum multiflorum extracts are known to improve memory and learning ability, and have neuroprotective and anti-aging activity. However, its function and the underlying mechanisms in neuroinflammation-mediated neurodegenerative disease remain poorly understood. In the present study, we investigated the anti-neuroinflammatory effects of several compounds from P. multiflorum, and found a novel compound, CRPE55IB. The CRPE55IB-induced suppression of NO and PGE 2 production correlated with inhibition of iNOS and COX-2 protein expression and promoter activity in lipopolysaccharide (LPS)-stimulated microglia. CRPE55IB also reduced the production of pro-inflammatory cytokines (TNF-α and IL-6) induced by LPS. Furthermore, investigation of the molecular mechanism indicated that CRPE55IB inhibited LPS-induced NF-κB activation by inactivating phosphorylation of IKKα/β, and phosphorylation and degradation of IκBα. We further found that CRPE55IB inhibited the phosphorylation of ERK and JNK at a lower concentration than that for p38 MAPK. Further experiments revealed that CRPE55IB treatment considerably increased the activation of Nrf2/ARE, and the expression of its target genes, including HO-1 and NQO1. Moreover, the Knockdown of Nrf2, HO-1, and NQO1 by siRNA abrogated the inhibitory effect of CRPE55IB on iNOS and COX-2 promoter activity. CRPE55IB also induced phosphorylation of AMPK/LKB/CaMKII in microglia. Analysis using a specific inhibitor of AMPK demonstrated that AMPK activation was involved in CRPE55IB-induced HO-1 and NQO1 expression. In addition, the CRPE55IB-induced anti-neuroinflammatory effect was abrogated by a specific inhibitor of AMPK, indicating the important role of AMPK in CRPE55IB-induced anti-neuroinflammation. Collectively, these results demonstrate that CRPE55IB exerts anti-neuroinflammatory effects against LPS via the Nrf2/AMPK signaling pathways. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Reduction of oxidative damages induced by titanium dioxide nanoparticles correlates with induction of the Nrf2 pathway by GSPE supplementation in mice.

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    Niu, Linpeng; Shao, Mengjiao; Liu, Yuan; Hu, Jinfeng; Li, Ruofan; Xie, Heran; Zhou, Lixiao; Shi, Lei; Zhang, Rong; Niu, Yujie

    2017-09-25

    Titanium dioxide nanoparticles (TiO 2 NPs) are widely used to additives in cosmetics, pharmaceuticals, paints and foods. Recent studies have demonstrated that TiO 2 NPs increased the risk of cancer and the mechanism might relate with oxidative stress. Grape seed procyanidin extract (GSPE) is a natural compound which has been demonstrated to possess a wide array of pharmacological and biochemical actions, including anti-inflammatory, anti-carcinogenic, and antioxidant properties. Our data show that GSPE prevents the changes of histopathology and biomarkers in heart, liver and kidney that occur in mice exposed to TiO 2 NPs. After pretreatment with GSPE, the DNA damage, reactive oxygen species (ROS) generation and malondialdehyde (MDA) content in mice exposed to TiO 2 NPs had statistically significant decreases in dose dependent manners. GSPE increased the expression of nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), NAD(P)H dehydrogenase[quinine] 1(NQO1), heme oxygenase 1 (HO-1) and glutamate-cysteine ligase catalytic subunit (GCLC). We conclude that grape seed procyanidin extract prevents the majority of tissue and molecular damage resulting from nanoparticle treatment. The protective effect of GSPE may be due to its strong antioxidative activities which related with the activated Nrf2 and its down-regulated genes including NQO1, HO-1 and GCLC. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Activation of Transcription Factor Nrf2 Signalling by the Sphingosine Kinase Inhibitor SKI-II Is Mediated by the Formation of Keap1 Dimers

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    Mercado, Nicolas; Kizawa, Yasuo; Ueda, Keitaro; Xiong, Yeping; Kimura, Genki; Moses, Audric; Curtis, Jonathan M.; Ito, Kazuhiro; Barnes, Peter J.

    2014-01-01

    Background Anti-oxidant capacity is crucial defence against environmental or endogenous oxidative stress. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that plays a key defensive role against oxidative and cytotoxic stress and cellular senescence. However, Nrf2 signalling is impaired in several aging-related diseases, such as chronic pulmonary obstructive disease (COPD), cancer, and neurodegenerative diseases. Thus, novel therapeutics that enhance Nrf2 signalling are an attractive approach to treat these diseases. Methodology/Principal Findings Nrf2 was stabilized by SKI-II (2-(p-hydroxyanilino)-4-(p-chlorophenyl) thiazole), which is a known sphingosine kinase inhibitor, in human bronchial epithelial cell line, BEAS2B, and in primary human bronchial epithelial cells, leading to enhancement of anti-oxidant proteins, such as HO-1, NQO1 and GCLM. The activation of Nrf2 was achieved by the generation of inactive dimerized form of Keap1, a negative regulator of Nrf2 expression, which was independent of sphingosine kinase inhibition. Using mice that were exposed to cigarette smoke, SKI-II induced Nrf2 expression together with HO-1 in their lungs. In addition, SKI-II reduced cigarette smoke mediated oxidative stress, macrophages and neutrophil infiltration and markers of inflammation in mice. Conclusions/Significance SKI-II appears to be a novel activator of Nrf2 signalling via the inactivation of Keap1. PMID:24505412

  8. The novel triterpenoid RTA 408 protects human retinal pigment epithelial cells against H2O2-induced cell injury via NF-E2-related factor 2 (Nrf2 activation

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    Xiaobin Liu

    2016-08-01

    Full Text Available Oxidative stress-induced retinal pigment epithelial (RPE cell damage is an important factor in the pathogenesis of age-related macular degeneration (AMD. Previous studies have shown that RTA 408, a synthetic triterpenoid compound, potently activates Nrf2. This study aimed to investigate the protective effects of RTA 408 in cultured RPE cells during oxidative stress and to determine the effects of RTA 408 on Nrf2 and its downstream target genes. Primary human RPE cells were pretreated with RTA 408 and then incubated in 200 μM H2O2 for 6 h. Cell viability was measured with the WST-8 assay. Apoptosis was quantitatively measured by annexin V/propidium iodide (PI double staining and Hoechst 33342 fluorescent staining. Reduced (GSH and oxidized glutathione (GSSG were measured using colorimetric assays. Nrf2 activation and its downstream effects on phase II enzymes were examined by Western blot. Treatment of RPE cells with nanomolar ranges (10 and 100 nM of RTA 408 markedly attenuated H2O2-induced viability loss and apoptosis. RTA 408 pretreatment significantly protected cells from oxidative stress-induced GSH loss, GSSG formation and decreased ROS production. RTA 408 activated Nrf2 and increased the expression of its downstream genes, such as HO-1, NQO1, SOD2, catalase, Grx1, and Trx1. Consequently, the enzyme activities of NQO1, Grx1, and Trx1 were fully protected by RTA 408 pretreatment under oxidative stress. Moreover, knockdown of Nrf2 by siRNA significantly reduced the cytoprotective effects of RTA 408. In conclusion, our data suggest that RTA 408 protect primary human RPE cells from oxidative stress-induced damage by activating Nrf2 and its downstream genes.

  9. Xyloketal B Exhibits Its Antioxidant Activity through Induction of HO-1 in Vascular Endothelial Cells and Zebrafish

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    Guan-Lei Wang

    2013-02-01

    Full Text Available We previously reported that a novel marine compound, xyloketal B, has strong antioxidative actions in different models of cardiovascular diseases. Induction of heme oxygenase-1 (HO-1, an important endogenous antioxidant enzyme, has been considered as a potential therapeutic strategy for cardiovascular diseases. We here investigated whether xyloketal B exhibits its antioxidant activity through induction of HO-1. In human umbilical vein endothelial cells (HUVECs, xyloketal B significantly induced HO-1 gene expression and translocation of the nuclear factor-erythroid 2-related factor 2 (Nrf-2 in a concentration- and time-dependent manner. The protection of xyloketal B against angiotensin II-induced apoptosis and reactive oxygen species (ROS production could be abrogated by the HO-1 specific inhibitor, tin protoporphyrin-IX (SnPP. Consistently, the suppressive effects of xyloketal B on NADPH oxidase activity could be reversed by SnPP in zebrafish embryos. In addition, xyloketal B induced Akt and Erk1/2 phosphorylation in a concentration- and time-dependent manner. Furthermore, PI3K inhibitor LY294002 and Erk1/2 inhibitor U0126 suppressed the induction of HO-1 and translocation of Nrf-2 by xyloketal B, whereas P38 inhibitor SB203580 did not. In conclusion, xyloketal B can induce HO-1 expression via PI3K/Akt/Nrf-2 pathways, and the induction of HO-1 is mainly responsible for the antioxidant and antiapoptotic actions of xyloketal B.

  10. Anti-inflammatory effects of novel polygonum multiflorum compound via inhibiting NF-κB/MAPK and upregulating the Nrf2 pathways in LPS-stimulated microglia.

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    Park, Sun Young; Jin, Mei Ling; Kang, Nam Jun; Park, Geuntae; Choi, Young-Whan

    2017-06-09

    The incorporation of Polygonum multiflorum into the diet can result in anti-aging effects owing to its wide range of biological and pharmaceutical properties. We investigated the anti-neuroinflammatory properties of CRPE56IGIH isolated from P. multiflorum by focusing on its role in the induction of phase II antioxidant enzymes and the modulation of upstream signaling pathways. In microglia, CRPE56IGIH significantly inhibited lipopolysaccharide (LPS)-stimulated nitric oxide and prostaglandin E 2 production with nonspecific cytotoxicity. CRPE56IGIH also markedly inhibited LPS-inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 protein and mRNA expression in the same manner as it inhibited nitric oxide and prostaglandin E 2 production. In the control cells, NF-κB transactivation and nuclear translocation occurred at a baseline level, which was significantly increased in response to LPS. However, pretreatment with CRPE56IGIH concentration-dependently inhibited the LPS-induced NF-κB transactivation and nuclear translocation. The phosphorylation of Janus kinase-signal transducers and activators of transcription and mitogen-activated protein kinases was markedly upregulated by LPS, but considerably and dose-dependently inhibited by pretreatment with CRPE56IGIH. Furthermore, CRPE56IGIH induced the expression of phase II antioxidant enzymes, including heme oxygenase-1 (HO-1) and NADPH dehydrogenase quinone-1 (NQO-1). The activation of upstream signaling pathways, such as the Nrf2 pathway, was significantly increased following CRPE56IGIH treatment. Furthermore, the anti-neuroinflammatory effect of CRPE56IGIH was reversed by transfection of Nrf2, HO-1, and NQO-1 siRNA. Our results indicated that CRPE56IGIH isolated from P. multiflorum could be used as a natural anti-neuroinflammatory agent that induces phase II antioxidant enzymes via Nrf2 signaling. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Transcription factor Nrf2 maintains the basal expression of Mdm2: An implication of the regulation of p53 signaling by Nrf2.

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    You, Aram; Nam, Chang-Won; Wakabayashi, Nobunao; Yamamoto, Masayuki; Kensler, Thomas W; Kwak, Mi-Kyoung

    2011-03-15

    Co-operated regulation of oxidative stress-response transcription factors would be an important issue for animals to determine the cell fate under environmental stress. This notion raises a possibility that NF-E2-related factor 2 (Nrf2), which confers cytoprotection against oxidative stress, and p53 can have a direct co-regulation network. In the current study, we have indentified that the expression of murine double minute 2 (Mdm2) is repressed in nrf2-deleted murine embryonic fibroblasts (MEFs). This was confirmed by microarray, RT-PCR, and immunoblot analyses, and further promoter analysis showed that Nrf2 is directly involved in the basal expression of Mdm2 through the antioxidant response element, which is located in the first intron of this gene. This linkage between Nrf2 and Mdm2 appears to cause the accumulation of p53 protein in nrf2-deficent MEFs. In addition, we show that ovarian carcinoma A2780 cells with Nrf2 shRNA expression displayed higher levels of p53 activation in response to hydrogen peroxide treatment, leading to increased cell death. Collectively, our results suggest novel evidence that the inhibition of Nrf2 can suppress Mdm2 expression, which may result in p53 signaling modulation. In addition, this observation supports the concept that Nrf2 inhibition in cancer cells can facilitate apoptotic response upon environmental stress. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Perspectives of the Nrf-2 signaling pathway in cancer progression and therapy

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    Priyanka Basak

    Full Text Available The Nuclear factor erythroid2-related factor2 (Nrf2, a master regulator of redox homoeostasis, is a key transcription factor regulating a wide array of genes for antioxidant and detoxification enzymes. It protects organs from various kinds of toxic insults. On the other hand, activation of Nrf2 is also correlated with cancer progression and chemoresistance. Downregulation of Nrf2 activity has attracted an increasing amount of attention as it may provide an alternative cancer therapy. In this review, we examine recent studies on roles of Nrf2 in several pathophysiological conditions emphasising cancer. We discuss elaborately the current knowledge on Nrf2 regulation including KEAP1-dependent and KEAP1-independent cascades. KEAP1/Nrf2 system is a master regulator of cellular response against a variety of environmental stresses. We also highlight several tightly controlled regulations of Nrf2 by numerous proteins, small molecules, toxic metals, etc. In addition, we evaluate the possible therapeutic approaches of increasing chemosensitivity via modulating Nrf2 signaling. Keywords: Nrf2, Transcription factor, KEAP1, Oxidative stress, Cell proliferation, Carcinogenesis, Chemoprevention

  13. Laminarin protects against hydrogen peroxide-induced oxidative damage in MRC-5 cells possibly via regulating NRF2.

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    Liu, Xue; Liu, Huaman; Zhai, Yi; Li, Yan; Zhu, Xue; Zhang, Wei

    2017-01-01

    Oxidative damage is a major cause of lung diseases, including pulmonary fibrosis. Laminarin is a kind of polysaccharide extracted from brown algae and plays vital roles in various biological processes. However, the functions and mechanisms of laminarin in pulmonary oxidative damage are poorly understood. This study aimed at investigating the protective effect of laminarin against pulmonary oxidative damage and underlying mechanisms. Human lung fibroblasts MRC-5 cells were treated with hydrogen peroxide to induce oxidative damage. Laminarin treatment was performed before or after hydrogen peroxide treatment, and then major indexes of oxidative damage, including superoxide dismutase (SOD), malondialdehyde (MDA), reduced glutathione (GSH) and catalase (CAT), were quantified by biochemical assays. The expression of oxidation-related factor, nuclear factor erythroid 2 like 2 (NRF2) was analyzed by qPCR, Western blot and immunofluorescence assay. NRF2 knockdown and overexpression were performed by cell transfection to reveal possible mechanisms. Results showed that laminarin treatment of 0.020 mg/mL for 24 h, especially the pre-treatment, could significantly relieve changes in SOD, MDA, GSH and CAT that were altered by hydrogen peroxide, and promote NRF2 mRNA ( P  < 0.001). NRF2 protein was also elevated by laminarin, and nuclear translocation was observed. Factors in NRF2 signaling pathways, including KEAP1, NQO1, GCLC and HO1, were all regulated by laminarin. Roles of NRF2 were tested, suggesting that NRF2 regulated the concentration of SOD, MDA, GSH and CAT, suppressed KEAP1, and promoted NQO1, GCLC and HO1. These findings suggested the protective role of laminarin against pulmonary oxidative damage, which might involve the regulation of NRF2 signaling pathways. This study provided information for the clinical application of laminarin to pulmonary diseases like pulmonary fibrosis.

  14. Astaxanthin protects against MPP+-induced oxidative stress in PC12 cells via the HO-1/NOX2 axis

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    Ye Qinyong

    2012-12-01

    Full Text Available Abstract Background Although the etiology of PD remains unclear, increasing evidence has shown that oxidative stress plays an important role in its pathogenesis and that of other neurodegenerative disorders. NOX2, a cytochrome subunit of NOX, transports electrons across the plasma membrane to generate ROS, leading to physiological and pathological processes. Heme oxygenase-1 (HO-1 can be rapidly induced by oxidative stress and other noxious stimuli in the brain or other tissues. Astaxanthin (ATX, a carotenoid with antioxidant properties, is 100–1000 times more effective than vitamin E. The present study investigated the neuroprotective effects of ATX on MPP+-induced oxidative stress in PC12 cells. Results MPP+ significantly decreased MTT levels in a concentration-dependent manner. Hemin, SnPPIX and ATX didn’t exhibit any cytotoxic effects on PC12 cells. Pretreatment with ATX (5, 10, 20 μM, caused intracellular ROS production in the MPP+ group to decrease by 13.06%, 22.13%, and 27.86%, respectively. MPP+ increased NOX2, NRF2 and HO-1 protein expression compared with control (p + treatment up-regulated both NOX2 (p + increased NOX2 and HO-1 expression with considerable fluorescence extending out from the perinuclear region toward the periphery; this was attenuated by DPI. Co-treatment with hemin or ATX significantly up-regulated HO-1 expression and decreased NOX2 expression with considerable fluorescence intensity (stronger than the control and MPP+ groups. Conclusions ATX suppresses MPP+-induced oxidative stress in PC12 cells via the HO-1/NOX2 axis. ATX should be strongly considered as a potential neuroprotectant and adjuvant therapy for patients with Parkinson’s disease.

  15. Baicalin Ameliorates Experimental Liver Cholestasis in Mice by Modulation of Oxidative Stress, Inflammation, and NRF2 Transcription Factor

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    Kezhen Shen

    2017-01-01

    Full Text Available Experimental cholestatic liver fibrosis was performed by bile duct ligation (BDL in mice, and significant liver injury was observed in 15 days. Administration of baicalin in mice significantly ameliorates liver fibrosis. Experimental cholestatic liver fibrosis was associated with induced gene expression of fibrotic markers such as collagen I, fibronectin, alpha smooth muscle actin (SMA, and connective tissue growth factor (CTGF; increased inflammatory cytokines (TNFα, MIP1α, IL1β, and MIP2; increased oxidative stress and reactive oxygen species- (ROS- inducing enzymes (NOX2 and iNOS; dysfunctional mitochondrial electron chain complexes; and apoptotic/necrotic cell death markers (DNA fragmentation, caspase 3 activity, and PARP activity. Baicalin administration on alternate day reduced fibrosis along with profibrotic gene expression, proinflammatory cytokines, oxidative stress, and cell death whereas improving the function of mitochondrial electron transport chain. We observed baicalin enhanced NRF2 activation by nuclear translocation and induced its target genes HO-1 and GCLM, thus enhancing antioxidant defense. Interplay of oxidative stress/inflammation and NRF2 were key players for baicalin-mediated protection. Stellate cell activation is crucial for initiation of fibrosis. Baicalin alleviated stellate cell activation and modulated TIMP1, SMA, collagen 1, and fibronectin in vitro. This study indicates that baicalin might be beneficial for reducing inflammation and fibrosis in liver injury models.

  16. Dietary luteolin protects against HgCl2-induced renal injury via activation of Nrf2-mediated signaling in rat.

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    Tan, Xiao; Liu, Biying; Lu, Jingjing; Li, Siyu; Baiyun, Ruiqi; Lv, Yueying; Lu, Qian; Zhang, Zhigang

    2018-02-01

    Luteolin (Lut) belongs to the flavonoid family with various beneficial bioactivities. Here, we investigated whether Lut attenuate mercuric chloride (HgCl 2 )-induced renal injury in rat. We found that oral gavage administration of Lut (80mg/kg) alleviated anemia and renal histology upon HgCl 2 treatment (80mg/L). Lut also significantly reduced HgCl 2 -induced oxidative stress and inflammatory, presenting as the reduced malondialdehyde (MDA) formation, increased glutathione (GSH) level, and inhibited activation of nuclear factor kappa B (NF-κB). Moreover, Lut protected renal cells from HgCl 2 -induced apoptosis, as assessed by Terminal deoxynucleotidyl transferase dUNT nick end labeling (TUNEL) assay and the protein levels of B-cell lymphoma gene 2 (Bcl-2), B-cell lymphoma-extra large (Bcl-xL), Bcl-2-associated X protein (Bax), and p53. Interestingly, Lut reduced renal mercuric accumulation in rat. Furthermore, Lut increased nuclear translocation of the nuclear factor-erythroid-2-related factor 2 (Nrf2), and subsequent protein expression of the antioxidant enzymes, heme oxygenase-1 (HO-1) and nicotinamide adenine dinucleotide phosphatase: quinone-acceptor 1 (NQO1). Our results suggest that Lut suppress HgCl 2 -induced renal injury via activation of Nrf2 signaling pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Arctigenin Increases Hemeoxygenase-1 Gene Expression by Modulating PI3K/AKT Signaling Pathway in Rat Primary Astrocytes.

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    Jeong, Yeon-Hui; Park, Jin-Sun; Kim, Dong-Hyun; Kim, Hee-Sun

    2014-11-01

    In the present study, we found that the natural compound arctigenin inhibited hydrogen peroxide-induced reactive oxygen species (ROS) production in rat primary astrocytes. Since hemeoxygenase-1 (HO-1) plays a critical role as an antioxidant defense factor in the brain, we examined the effect of arctigenin on HO-1 expression in rat primary astrocytes. We found that arctigenin increased HO-1 mRNA and protein levels. Arctigenin also increases the nuclear translocation and DNA binding of Nrf2/c-Jun to the antioxidant response element (ARE) on HO-1 promoter. In addition, arctigenin increased ARE-mediated transcriptional activities in rat primary astrocytes. Further mechanistic studies revealed that arctigenin increased the phosphorylation of AKT, a downstream substrate of phosphatidylinositol 3-kinase (PI3K). Treatment of cells with a PI3K-specific inhibitor, LY294002, suppressed the HO-1 expression, Nrf2 DNA binding and ARE-mediated transcriptional activities in arctigenin-treated astrocyte cells. The results collectively suggest that PI3K/AKT signaling pathway is at least partly involved in HO-1 expression by arctigenin via modulation of Nrf2/ARE axis in rat primary astrocytes.

  18. Protective Effects of Maillard Reaction Products of Whey Protein Concentrate against Oxidative Stress through an Nrf2-Dependent Pathway in HepG2 Cells.

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    Pyo, Min Cheol; Yang, Sung-Yong; Chun, Su-Hyun; Oh, Nam Su; Lee, Kwang-Won

    2016-09-01

    Whey protein concentrate (WPC), which contains α-lactalbumin and β-lactoglobulin, is utilized widely in the food industry. The Maillard reaction is a complex reaction that produces Maillard reaction products (MRPs), which are associated with the formation of antioxidant compounds. In this study, the hepatoprotection activity of MRPs of WPC against oxidative stress through the nuclear factor-E2-related factor 2 (Nrf2)-dependent antioxidant pathway in HepG2 cells was examined. Glucose-whey protein concentrate conjugate (Glc-WPC) was obtained from Maillard reaction between WPC and glucose. The fluorescence intensity of Glc-WPC increased after 7 d compared to native WPC, and resulted in loss of 48% of the free amino groups of WPC. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of Glc-WPC showed the presence of a high-molecular-weight portion. Treatment of HepG2 cells with Glc-WPC increased cell viability in the presence of oxidative stress, inhibited the generation of intracellular reactive oxygen species by tert-butyl hydroperoxide (t-BHP), and increased the glutathione level. Nrf2 translocation and Nrf2, reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H)-quinone oxidoreductase 1 (NOQ1), heme oxygenase-1 (HO-1), glutamate-L-cysteine ligase (GCL)M and GCLC mRNA levels were increased by Glc-WPC. Also, Glc-WPC increased the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK). The results of this study demonstrate that Glc-WPC activates the Nrf2-dependent pathway through the phosphorylation of ERK1/2 and JNK in HepG2 cells, and induces production of antioxidant enzymes and phase II enzymes.

  19. NRF2 deficiency replicates transcriptomic changes in Alzheimer's patients and worsens APP and TAU pathology

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    Ana I. Rojo

    2017-10-01

    Full Text Available Failure to translate successful neuroprotective preclinical data to a clinical setting in Alzheimer's disease (AD indicates that amyloidopathy and tauopathy alone provide an incomplete view of disease. We have tested here the relevance of additional homeostatic deviations that result from loss of activity of transcription factor NRF2, a crucial regulator of multiple stress responses whose activity declines with ageing. A transcriptomic analysis demonstrated that NRF2-KO mouse brains reproduce 7 and 10 of the most dysregulated pathways of human ageing and AD brains, respectively. Then, we generated a mouse that combines amyloidopathy and tauopathy with either wild type (AT-NRF2-WT or NRF2-deficiency (AT-NRF2-KO. AT-NRF2-KO brains presented increased markers of oxidative stress and neuroinflammation as well as higher levels of insoluble phosphorylated-TAU and Aβ*56 compared to AT-NRF2-WT mice. Young adult AT-NRF2-KO mice exhibited deficits in spatial learning and memory and reduced long term potentiation in the perforant pathway. This study demonstrates the relevance of normal homeostatic responses that decline with ageing, such as NRF2 activity, in the protection against proteotoxic, inflammatory and oxidative stress and provide a new strategy to fight AD.

  20. Propofol induces proliferation and invasion of gallbladder cancer cells through activation of Nrf2

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    Zhang Lingmin

    2012-08-01

    Full Text Available Abstract Background Propofol is one of the most commonly used intravenous anaesthetic agents during cancer resection surgery, but the effect of propofol on gallbladder cancer is not clear. NF-E2-related factor 2 (Nrf2 is abundantly expressed in cancer cells and relates to proliferation, invasion, and chemoresistance. The aims of the current study were to evaluate effects of propofol on the behavior of human GC cells and role of Nrf2 in these effects. Method The effects of propofol on cell proliferation, apoptosis, and invasion were detected by MTT assays, flow cytometry, and transwell assay. Also, activation of Nrf2 was determined by western blot, RT-PCR, and immunofluorescence assays. Nrf2 was knocked-down in GBC-SD cells by shRNA before evaluating the role of Nrf2 in the influence of propofol on biological behaviors. Results Propofol promoted the proliferation of GBC-SD cells in a dose- and time- dependent manner. After exposure to propofol for 48 h, GBC-SD cells showed decreased apoptosis and increased invasion. Also, propofol over-expressed Nrf2 at both the protein and mRNA levels and induced translocation of Nrf2 into the nucleus. Finally, loss of Nrf2 by shRNA reversed the effect of propofol on cell proliferation, apoptosis, and invasion. Conclusion Propofol induces proliferation and promotes invasion of GC cells through activation of Nrf2.

  1. Overview of Nrf2 as Therapeutic Target in Epilepsy

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    Liliana Carmona-Aparicio

    2015-08-01

    Full Text Available Oxidative stress is a biochemical state of imbalance in the production of reactive oxygen and nitrogen species and antioxidant defenses. It is involved in the physiopathology of degenerative and chronic neuronal disorders, such as epilepsy. Experimental evidence in humans and animals support the involvement of oxidative stress before and after seizures. In the past few years, research has increasingly focused on the molecular pathways of this process, such as that involving transcription factor nuclear factor E2-related factor 2 (Nrf2, which plays a central role in the regulation of antioxidant response elements (ARE and modulates cellular redox status. The aim of this review is to present experimental evidence on the role of Nrf2 in this neurological disorder and to further determine the therapeutic impact of Nrf2 in epilepsy.

  2. Review of NRF2-regulated genes induced in response to antioxidants

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    Ahmed Atia, Azman Abdullah

    2014-04-01

    Full Text Available Nuclear factor (erythroid-derived 2 -like 2 (Nrf2 is a transcription factor that plays an important role in the cellular protection against free radical damage and reduce the incidence of radical derived degenerative diseases such as cancer. Nrf2 is referred to as the “master regulator” of the antioxidant response due to the fact that it modulates the expression of several genes including phase-2 and antioxidant enzymes playing a crucial role in detoxification of electrophiles and reactive oxygen species (ROS, including glutathione-S-transferase (GST, gamma-glutamyl cysteine ligase (γ-GCL, glutathione-S-reductase (GSR, NAD(PH:quinoneoxidoreductase-1 (NQO1, heme oxygenase-1 (HO-1, etc. Following dissociation from it obligatory partner Kelch like ECH-associated protein 1 (Keap1, Nrf2 translocates to the nucleus and transactivates the antioxidant response element (ARE in the promoter region of several antioxidant genes. In this review, we discuss the role of the Nrf2 system, with particular focus on Nrf2-controlled target genes.

  3. Preconditioning with Ginkgo biloba (EGb 761®) provides neuroprotection through HO1 and CRMP2.

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    Nada, Shadia E; Shah, Zahoor A

    2012-04-01

    Ginkgo biloba/EGb 761® (EGb 761) is a popular and standardized natural extract used worldwide for the treatment of many ailments. Although EGb 761 is purported to have a plethora of benefits, here, we were interested to study the neuroprotective properties of EGb 761 and its components and determine whether nuclear factor E2 (Nrf2)/heme oxygenase 1 (HO1) induction of the collapsin response mediator protein 2 (CRMP2) pathway contributes to neuroprotection. Mice were pretreated with EGb 761 or one of its constituents (bilobalide, ginkgolide A, ginkgolide B, and terpene free material [TFM]) for 7days and then subjected to transient middle cerebral artery occlusion (tMCAO) and 48 h of reperfusion. All components except TFM significantly reduced infarct volumes and neurologic deficits. Next, we examined the antioxidant and neuritogenic properties of EGb 761 in primary neurons. Compared with vehicle-treated cells, pretreatment with EGb 761 significantly enhanced the survival of neurons exposed to tertiary butylhydroperoxide (t-BuOOH), hydrogen peroxide (H2O2), and N-methyl-D-aspartate (NMDA). Bilobalide and ginkgolide A also protected cells against NMDA-induced excitotoxicity. Immunofluorescence and Western blot analysis showed that EGb 761 pretreatment significantly increased the protein expression levels of Nrf2, HO1, GAPDH, β-actin, CRMP2, and histone H3 during t-BuOOH-induced oxidative stress. These findings suggest that EGb 761 not only has antioxidant activity but also neuritogenic potential. Demonstrating such effects for possible drug discovery may prove beneficial in stroke and ischemic brain injury. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Oligomeric proanthocyanidins protects A549 cells against H2O2-induced oxidative stress via the Nrf2-ARE pathway.

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    Sun, Chao; Jin, Weiguo; Shi, Hongcan

    2017-06-01

    Oxidative signaling and oxidative stress contribute to aging, cancer and diseases resulting from lung fibrosis. In this study, we explored the anti-oxidative potential of oligomeric proanthocyanidins (OPCs), natural flavonoid compounds. We examined the protective effects of OPCs against hydrogen peroxide (H2O2)-induced oxidative stress in non-small cell lung cancer cells (A549). We demonstrated that OPC markedly attenuated H2O2-induced A549 cell viability, as shown by by 3-[4,5-dimethylthiazol-2-yl)]-2,5-diphenyl-tetrazolium bromide (MTT) assay. At the same time, OPC inhibited H2O2-induced oxidative stress by significantly increasing the activities of superoxide dismutase, catalase and glutathione, and reducing the levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Treatment of the A549 cells with OPC significantly promoted the nuclear translocation of NF-E2-related factor 2 (Nrf2) and significantly enhanced the expression of its target genes [heme oxygenase-1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1) and thioredoxin reductase 1 (TXNRD1)] with different fold change values at both the mRNA and protein level. The knockout of Nrf2 using CRISPR/Cas9 technology attenuated OPC-mediated ARE gene transcription, and almost abolished the OPC-mediated protective effects against H2O2-induced oxidative stress. On the whole, our study suggests that OPC plays an important role in controlling the antioxidant response of A549 cells via the Nrf2-ARE pathway.

  5. Targeting NRF2 signaling for cancer chemoprevention

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    Kwak, Mi-Kyoung; Kensler, Thomas W.

    2010-01-01

    Modulation of the metabolism and disposition of carcinogens through induction of cytoprotective enzymes is one of several promising strategies to prevent cancer. Chemopreventive efficacies of inducers such as dithiolethiones and sulforaphane have been extensively studied in animals as well as in humans. The KEAP1-NRF2 system is a key, but not unilateral, molecular target for these chemopreventive agents. The transcription factor NRF2 (NF-E2-related factor 2) is a master regulator of the expression of a subset of genes, which produce proteins responsible for the detoxication of electrophiles and reactive oxygen species as well as the removal or repair of some of their damage products. It is believed that chemopreventive enzyme inducers affect the interaction between KEAP1 and NRF2 through either mediating conformational changes of the KEAP1 protein or activating phosphorylation cascades targeting the KEAP1-NRF2 complex. These events in turn affect NRF2 stability and trafficking. Recent advances elucidating the underlying structural biology of KEAP1-NRF2 signaling and identification of the gene clusters under the transcriptional control of NRF2 are facilitating understanding of the potential pleiotropic effects of NRF2 activators and discovery of novel classes of potent chemopreventive agents such as the triterpenoids. Although there is appropriately a concern regarding a deleterious role of the KEAP1-NRF2 system in cancer cell biology, especially as the pathway affects cell survival and drug resistance, the development and the use of NRF2 activators as chemopreventive agents still holds a great promise for protection of normal cells from a diversity of environmental stresses that contribute to the burden of cancer and other chronic, degenerative diseases.

  6. Hepatocyte-specific deletion of the keap1 gene activates Nrf2 and confers potent resistance against acute drug toxicity

    International Nuclear Information System (INIS)

    Okawa, Hiromi; Motohashi, Hozumi; Kobayashi, Akira; Aburatani, Hiroyuki; Kensler, Thomas W.; Yamamoto, Masayuki

    2006-01-01

    Nrf2 is a key regulator of many detoxifying enzyme genes, and cytoplasmic protein Keap1 represses the Nrf2 activity under quiescent conditions. Germ line deletion of the keap1 gene results in constitutive activation of Nrf2, but the pups unexpectedly died before weaning. To investigate how constitutive activation of Nrf2 influences the detoxification system in adult mice, we generated mice bearing a hepatocyte-specific disruption of the keap1 gene. Homozygous mice were viable and their livers displayed no apparent abnormalities, but nuclear accumulation of Nrf2 is elevated. Microarray analysis revealed that, while many detoxifying enzyme genes are highly expressed, some of the typical Nrf2-dependent genes are only marginally increased in the Keap1-deficient liver. The mutant mice were significantly more resistant to toxic doses of acetaminophen than control animals. These results demonstrate that chronic activation of Nrf2 confers animals with resistance to xenobiotics without affecting the morphological and physiological integrity of hepatocytes

  7. NRF2/Long Noncoding RNA ROR Signaling Regulates Mammary Stem Cell Expansion and Protects against Estrogen Genotoxicity*

    Science.gov (United States)

    Zhang, Yongshu; Xia, Jixiang; Li, Qinglin; Yao, Yuan; Eades, Gabriel; Gernapudi, Ramkishore; Duru, Nadire; Kensler, Thomas W.; Zhou, Qun

    2014-01-01

    Long noncoding RNAs (lncRNAs) have emerged as key regulators of gene expression in embryonic stem cell (ESC) self-renewal and differentiation. In ESCs, lncRNAs are regulated at the genetic level via transcription factor binding to lncRNA gene promoters. Here we demonstrate that the key cytoprotective transcription factor NRF2 controls lncRNA expression in mammary stem cells. By profiling lncRNAs in wild-type and NRF2 knockdown mammary stem cells, we demonstrate that the lncRNA ROR, a regulator of embryonic stem cell pluripotency, is overexpressed upon NRF2 knockdown. We performed promoter analyses and examined predicted NRF2 binding elements in the ROR promoter using luciferase reporter constructs of a ROR promoter deletion series. Our studies revealed that NRF2 binds to two specific NRF2 response elements flanking the ROR promoter and that these two NRF2 response elements are equally important to suppress ROR transcription. In addition, we identified associated H3K27me3 chromatin modification and EZH2 binding at the ROR promoter that was dependent on NRF2 binding. We observed that NRF2 knockdown or ROR overexpression leads to increased stem cell self-renewal in mammary stem cells. Furthermore, we demonstrate Nrf2 regulation of the mammary stem cell population in vivo. These observations provide further evidence for the critical role of NRF2 in maintaining normal stem cell subpopulations in mammary epithelium. PMID:25231996

  8. NRF2/long noncoding RNA ROR signaling regulates mammary stem cell expansion and protects against estrogen genotoxicity.

    Science.gov (United States)

    Zhang, Yongshu; Xia, Jixiang; Li, Qinglin; Yao, Yuan; Eades, Gabriel; Gernapudi, Ramkishore; Duru, Nadire; Kensler, Thomas W; Zhou, Qun

    2014-11-07

    Long noncoding RNAs (lncRNAs) have emerged as key regulators of gene expression in embryonic stem cell (ESC) self-renewal and differentiation. In ESCs, lncRNAs are regulated at the genetic level via transcription factor binding to lncRNA gene promoters. Here we demonstrate that the key cytoprotective transcription factor NRF2 controls lncRNA expression in mammary stem cells. By profiling lncRNAs in wild-type and NRF2 knockdown mammary stem cells, we demonstrate that the lncRNA ROR, a regulator of embryonic stem cell pluripotency, is overexpressed upon NRF2 knockdown. We performed promoter analyses and examined predicted NRF2 binding elements in the ROR promoter using luciferase reporter constructs of a ROR promoter deletion series. Our studies revealed that NRF2 binds to two specific NRF2 response elements flanking the ROR promoter and that these two NRF2 response elements are equally important to suppress ROR transcription. In addition, we identified associated H3K27me3 chromatin modification and EZH2 binding at the ROR promoter that was dependent on NRF2 binding. We observed that NRF2 knockdown or ROR overexpression leads to increased stem cell self-renewal in mammary stem cells. Furthermore, we demonstrate Nrf2 regulation of the mammary stem cell population in vivo. These observations provide further evidence for the critical role of NRF2 in maintaining normal stem cell subpopulations in mammary epithelium. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Disruption of Nrf2, a key inducer of antioxidant defenses, attenuates ApoE-mediated atherosclerosis in mice.

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    Thomas E Sussan

    Full Text Available BACKGROUND: Oxidative stress and inflammation are two critical factors that drive the formation of plaques in atherosclerosis. Nrf2 is a redox-sensitive transcription factor that upregulates a battery of antioxidative genes and cytoprotective enzymes that constitute the cellular response to oxidative stress. Our previous studies have shown that disruption of Nrf2 in mice (Nrf2(-/- causes increased susceptibility to pulmonary emphysema, asthma and sepsis due to increased oxidative stress and inflammation. Here we have tested the hypothesis that disruption of Nrf2 in mice causes increased atherosclerosis. PRINCIPAL FINDINGS: To investigate the role of Nrf2 in the development of atherosclerosis, we crossed Nrf2(-/- mice with apoliporotein E-deficient (ApoE(-/- mice. ApoE(-/- and ApoE(-/-Nrf2(-/- mice were fed an atherogenic diet for 20 weeks, and plaque area was assessed in the aortas. Surprisingly, ApoE(-/-Nrf2(-/- mice exhibited significantly smaller plaque area than ApoE(-/- controls (11.5% vs 29.5%. This decrease in plaque area observed in ApoE(-/-Nrf2(-/- mice was associated with a significant decrease in uptake of modified low density lipoproteins (AcLDL by isolated macrophages from ApoE(-/-Nrf2(-/- mice. Furthermore, atherosclerotic plaques and isolated macrophages from ApoE(-/-Nrf2(-/- mice exhibited decreased expression of the scavenger receptor CD36. CONCLUSIONS: Nrf2 is pro-atherogenic in mice, despite its antioxidative function. The net pro-atherogenic effect of Nrf2 may be mediated via positive regulation of CD36. Our data demonstrates that the potential effects of Nrf2-targeted therapies on cardiovascular disease need to be investigated.

  10. Eriodictyol-7-O-glucoside activates Nrf2 and protects against cerebral ischemic injury

    International Nuclear Information System (INIS)

    Jing, Xu; Ren, Dongmei; Wei, Xinbing; Shi, Huanying; Zhang, Xiumei; Perez, Ruth G.; Lou, Haiyan; Lou, Hongxiang

    2013-01-01

    Stroke is a complex disease that may involve oxidative stress-related pathways in its pathogenesis. The nuclear factor erythroid-2-related factor 2/antioxidant response element (Nrf2/ARE) pathway plays an important role in inducing phase II detoxifying enzymes and antioxidant proteins and thus has been considered a potential target for neuroprotection in stroke. The aim of the present study was to determine whether eriodictyol-7-O-glucoside (E7G), a novel Nrf2 activator, can protect against cerebral ischemic injury and to understand the role of the Nrf2/ARE pathway in neuroprotection. In primary cultured astrocytes, E7G increased the nuclear localization of Nrf2 and induced the expression of the Nrf2/ARE-dependent genes. Exposure of astrocytes to E7G provided protection against oxygen and glucose deprivation (OGD)-induced oxidative insult. The protective effect of E7G was abolished by RNA interference-mediated knockdown of Nrf2 expression. In vivo administration of E7G in a rat model of focal cerebral ischemia significantly reduced the amount of brain damage and ameliorated neurological deficits. These data demonstrate that activation of Nrf2/ARE signaling by E7G is directly associated with its neuroprotection against oxidative stress-induced ischemic injury and suggest that targeting the Nrf2/ARE pathway may be a promising approach for therapeutic intervention in stroke. - Highlights: • E7G activates Nrf2 in astrocytes. • E7G stimulates expression of Nrf2-mediated cytoprotective proteins in astrocytes. • E7G protects astrocytes against OGD-induced cell death and apoptosis. • The neuroprotective effect of E7G involves the Nrf2/ARE pathway. • E7G protects rats against cerebral ischemic injury

  11. Glucose availability is a decisive factor for Nrf2-mediated gene expression

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    Elke H. Heiss

    2013-01-01

    Full Text Available Activation of the transcription factor Nrf2 (nuclear factor-erythroid 2-related factor 2 is one of the major cellular defense lines against oxidative and xenobiotic stress, but also influences genes involved in lipid and glucose metabolism. It is unresolved whether the cytoprotective and metabolic responses mediated by Nrf2 are connected or separable events in non-malignant cells. In this study we show that activation of Nrf2, either by the small molecule sulforaphane or knockout of the Nrf2 inhibitor Keap1, leads to increased cellular glucose uptake and increased glucose addiction in fibroblasts. Upon Nrf2 activation glucose is preferentially metabolized through the pentose phosphate pathway with increased production of NADPH. Interference with the supply of glucose or the pentose phosphate pathway and NADPH generation not only hampers Nrf2-mediated detoxification of reactive oxygen species on the enzyme level but also Nrf2-initiated expression of antioxidant defense proteins, such as glutathione reductase and heme-oxygenase1. We conclude that the Nrf2-dependent protection against oxidative stress relies on an intact pentose phosphate pathway and that there is crosstalk between metabolism and detoxification already at the level of gene expression in mammalian cells.

  12. Arctigenin Increases Hemeoxygenase-1 Gene Expression by Modulating PI3K/AKT Signaling Pathway in Rat Primary Astrocytes

    OpenAIRE

    Jeong, Yeon-Hui; Park, Jin-Sun; Kim, Dong-Hyun; Kim, Hee-Sun

    2014-01-01

    In the present study, we found that the natural compound arctigenin inhibited hydrogen peroxide-induced reactive oxygen species (ROS) production in rat primary astrocytes. Since hemeoxygenase-1 (HO-1) plays a critical role as an antioxidant defense factor in the brain, we examined the effect of arctigenin on HO-1 expression in rat primary astrocytes. We found that arctigenin increased HO-1 mRNA and protein levels. Arctigenin also increases the nuclear translocation and DNA binding of Nrf2/c-J...

  13. Nrf2 impacts cellular bioenergetics by controlling substrate availability for mitochondrial respiration

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    Kira M. Holmström

    2013-06-01

    Transcription factor Nrf2 and its repressor Keap1 regulate a network of cytoprotective genes involving more than 1% of the genome, their best known targets being drug-metabolizing and antioxidant genes. Here we demonstrate a novel role for this pathway in directly regulating mitochondrial bioenergetics in murine neurons and embryonic fibroblasts. Loss of Nrf2 leads to mitochondrial depolarisation, decreased ATP levels and impaired respiration, whereas genetic activation of Nrf2 increases the mitochondrial membrane potential and ATP levels, the rate of respiration and the efficiency of oxidative phosphorylation. We further show that Nrf2-deficient cells have increased production of ATP in glycolysis, which is then used by the F1Fo-ATPase for maintenance of the mitochondrial membrane potential. While the levels and in vitro activities of the respiratory complexes are unaffected by Nrf2 deletion, their activities in isolated mitochondria and intact live cells are substantially impaired. In addition, the rate of regeneration of NADH after inhibition of respiration is much slower in Nrf2-knockout cells than in their wild-type counterparts. Taken together, these results show that Nrf2 directly regulates cellular energy metabolism through modulating the availability of substrates for mitochondrial respiration. Our findings highlight the importance of efficient energy metabolism in Nrf2-mediated cytoprotection.

  14. High NRF2 expression controls endoplasmic reticulum stress induced apoptosis in multiple myeloma.

    Science.gov (United States)

    Sun, Yu; Abdul Aziz, Amina; Bowles, Kristian; Rushworth, Stuart

    2018-01-01

    Multiple myeloma (MM) is an incurable disease characterized by clonal plasma cell proliferation. The stress response transcription factor Nuclear factor erythroid 2 [NF-E2]-related factor 2 (NRF2) is known to be activated in MM in response to proteasome inhibitors (PI). Here, we hypothesize that the transcription factor NRF2 whose physiological role is to protect cells from reactive oxygen species via the regulation of drug metabolism and antioxidant gene plays an important role in MM cells survival and proliferation. We report for the first time that NRF2 is constitutively activated in circa 50% of MM primary samples and all MM cell lines. Moreover, genetic inhibition of constitutively expressed NRF2 reduced MM cell viability. We confirm that PI induced further expression of NRF2 in MM cell lines and primary MM. Furthermore, genetic inhibition of NRF2 of PI treated MM cells increased ER-stress through the regulation of CCAAT-enhancer-binding protein homologous protein (CHOP). Finally, inhibition of NRF2 in combination with PI treatment significantly increased apoptosis in MM cells. Here we identify NRF2 as a key regulator of MM survival in treatment naive and PI treated cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. HO-1 Is Essential for Tetrahydroxystilbene Glucoside Mediated Mitochondrial Biogenesis and Anti-Inflammation Process in LPS-Treated RAW264.7 Macrophages

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    Weihua Yu

    2017-01-01

    Full Text Available 2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG, an important monomer extracted from Polygonum multiflorum, can prevent a number of inflammation associated chronic diseases. However, the mechanism involved in TSG inducing anti-inflammatory role remains unclear. As an inducible antioxidant enzyme, Heme oxygenase-1 (HO-1, is crucial for protecting the mammalian cells against adverse stimuli. Here, we found that the TSG treatment strongly induces the expression of HO-1 in an NRF2-depended manner. Meanwhile, TSG increased the mitochondrial mass through upregulation of the mitochondrial biogenesis activators (PGC-1α, NRF1, and TFAM as well as the mitochondrial complex IV. Furthermore, TSG attenuated Lipopolysaccharide (LPS mediated RAW264.7 cells activation and secretion of proinflammatory cytokines, including interleukin-6 (IL-6 and tumor necrosis factor-α (TNF-α. Zinc Protoporphyrin (ZnPP, a selective inhibitor of HO-1 activity, was able to attenuate TSG mediated mitochondrial biogenesis and anti-inflammatory process. Finally, we observed that LPS induced obvious mtDNA depletion and ATP deficiency, which indicated a severe damage of mitochondria. TSG restored the LPS induced mitochondrial dysfunction via activation of the mitochondrial biogenesis. ZnPP treatment markedly reversed the inhibitory effects of TSG on mitochondrial damage and oxidative stress in LPS stimulated macrophages. Taken together, these findings suggest that TSG enhances mitochondrial biogenesis and function mainly via activation the HO-1. TSG can be developed as a potential drug for treatment of inflammatory diseases.

  16. The anti-inflammatory activity of Phellinus linteus (Berk. & M.A. Curt.) is mediated through the PKCdelta/Nrf2/ARE signaling to up-regulation of heme oxygenase-1.

    Science.gov (United States)

    Kim, Byung-Chul; Jeon, Woo-Kwang; Hong, Hye-Young; Jeon, Kyung-Bum; Hahn, Jang-Hee; Kim, Young-Myeong; Numazawa, Satoshi; Yosida, Takemi; Park, Eun-Hee; Lim, Chang-Jin

    2007-09-05

    It has been reported that heme oxygenase-1 (HO-1) mediates the anti-inflammatory activity of the n-BuOH subfraction (PL) prepared from fruiting bodies of Phellinus linteus. This continuing work aimed to elucidate the signaling pathway to the up-regulation of HO-1 by PL. In RAW264.7 macrophage cells, PL was able to enhance phosphorylation of protein kinase Cdelta (PKCdelta), but not PKCalpha/betaII, in a time-dependent manner. PL-induced HO-1 expression was dramatically released by GF109203X, a general inhibitor of PKC, and rottlerin, a specific PKCdelta inhibitor but not by Gö6976, a selective inhibitor for PKCalpha/beta. Additionally, PL treatment resulted in a marked increase in antioxidant response element (ARE)-driven transcriptional activity, which was dependent on PKCdelta but not PKCalpha. An increase by PL treatment in the ARE-driven transcriptional activity was further enhanced by Nrf2, whereas it was diminished by Keap1. Furthermore, pretreatment of rottlerin and overexpression of PKCdelta (K376R), a kinase-inactive form of PKCdelta, partly blocked the suppression by PL of nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression, and iNOS promoter activity, which were elevated in the lypopolysaccharide (LPS)-activated macrophages. Similarly, expression of matrix metalloproteinase-9 (MMP-9) and its promoter activity were suppressed by PL, which were dependent upon PKCdelta. The present findings indicate that Phellinus linteus gives rise to an anti-inflammatory activity though the PKCdelta/Nrf2/ARE signaling to the up-regulation of HO-1 in an in vitro inflammation model.

  17. Bixin protects mice against ventilation-induced lung injury in an NRF2-dependent manner.

    Science.gov (United States)

    Tao, Shasha; Rojo de la Vega, Montserrat; Quijada, Hector; Wondrak, Georg T; Wang, Ting; Garcia, Joe G N; Zhang, Donna D

    2016-01-05

    Mechanical ventilation (MV) is a therapeutic intervention widely used in the clinic to assist patients that have difficulty breathing due to lung edema, trauma, or general anesthesia. However, MV causes ventilator-induced lung injury (VILI), a condition characterized by increased permeability of the alveolar-capillary barrier that results in edema, hemorrhage, and neutrophil infiltration, leading to exacerbated lung inflammation and oxidative stress. This study explored the feasibility of using bixin, a canonical NRF2 inducer identified during the current study, to ameliorate lung damage in a murine VILI model. In vitro, bixin was found to activate the NRF2 signaling pathway through blockage of ubiquitylation and degradation of NRF2 in a KEAP1-C151 dependent manner; intraperitoneal (IP) injection of bixin led to pulmonary upregulation of the NRF2 response in vivo. Remarkably, IP administration of bixin restored normal lung morphology and attenuated inflammatory response and oxidative DNA damage following MV. This observed beneficial effect of bixin derived from induction of the NRF2 cytoprotective response since it was only observed in Nrf2(+/+) but not in Nrf2(-/-) mice. This is the first study providing proof-of-concept that NRF2 activators can be developed into pharmacological agents for clinical use to prevent patients from lung injury during MV treatment.

  18. Escin activates AKT-Nrf2 signaling to protect retinal pigment epithelium cells from oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Kaijun [Eye Center, The 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou (China); Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou (China); Jiang, Yiqian [The First People Hospital of Xiaoshan, Hangzhou (China); Wang, Wei; Ma, Jian [Eye Center, The 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou (China); Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou (China); Chen, Min, E-mail: eyedrchenminzj@163.com [Eye Center, The 2nd Affiliated Hospital, Medical College of Zhejiang University, Hangzhou (China); Zhejiang Provincial Key Lab of Ophthalmology, Hangzhou (China)

    2015-12-25

    Here we explored the anti-oxidative and cytoprotective potentials of escin, a natural triterpene-saponin, against hydrogen peroxide (H{sub 2}O{sub 2}) in retinal pigment epithelium (RPE) cells. We showed that escin remarkably attenuated H{sub 2}O{sub 2}-induced death and apoptosis of established (ARPE-19) and primary murine RPE cells. Meanwhile, ROS production and lipid peroxidation by H{sub 2}O{sub 2} were remarkably inhibited by escin. Escin treatment in RPE cells resulted in NF-E2-related factor 2 (Nrf2) signaling activation, evidenced by transcription of anti-oxidant-responsive element (ARE)-regulated genes, including HO-1, NQO-1 and SRXN-1. Knockdown of Nrf2 through targeted shRNAs/siRNAs alleviated escin-mediated ARE gene transcription, and almost abolished escin-mediated anti-oxidant activity and RPE cytoprotection against H{sub 2}O{sub 2}. Reversely, escin was more potent against H{sub 2}O{sub 2} damages in Nrf2-over-expressed ARPE-19 cells. Further studies showed that escin-induced Nrf2 activation in RPE cells required AKT signaling. AKT inhibitors (LY294002 and perifosine) blocked escin-induced AKT activation, and dramatically inhibited Nrf2 phosphorylation, its cytosol accumulation and nuclear translocation in RPE cells. Escin-induced RPE cytoprotection against H{sub 2}O{sub 2} was also alleviated by the AKT inhibitors. Together, these results demonstrate that escin protects RPE cells from oxidative stress possibly through activating AKT-Nrf2 signaling.

  19. Attenuation of Aβ25–35-induced parallel autophagic and apoptotic cell death by gypenoside XVII through the estrogen receptor-dependent activation of Nrf2/ARE pathways

    International Nuclear Information System (INIS)

    Meng, Xiangbao; Wang, Min; Sun, Guibo; Ye, Jingxue; Zhou, Yanhui; Dong, Xi; Wang, Tingting; Lu, Shan; Sun, Xiaobo

    2014-01-01

    Amyloid-beta (Aβ) has a pivotal function in the pathogenesis of Alzheimer's disease. To investigate Aβ neurotoxicity, we used an in vitro model that involves Aβ 25–35 -induced cell death in the nerve growth factor-induced differentiation of PC12 cells. Aβ 25–35 (20 μM) treatment for 24 h caused apoptotic cell death, as evidenced by significant cell viability reduction, LDH release, phosphatidylserine externalization, mitochondrial membrane potential disruption, cytochrome c release, caspase-3 activation, PARP cleavage, and DNA fragmentation in PC12 cells. Aβ 25–35 treatment led to autophagic cell death, as evidenced by augmented GFP-LC3 puncta, conversion of LC3-I to LC3-II, and increased LC3-II/LC3-I ratio. Aβ 25–35 treatment induced oxidative stress, as evidenced by intracellular ROS accumulation and increased production of mitochondrial superoxide, malondialdehyde, protein carbonyl, and 8-OHdG. Phytoestrogens have been proved to be protective against Aβ-induced neurotoxicity and regarded as relatively safe targets for AD drug development. Gypenoside XVII (GP-17) is a novel phytoestrogen isolated from Gynostemma pentaphyllum or Panax notoginseng. Pretreatment with GP-17 (10 μM) for 12 h increased estrogen response element reporter activity, activated PI3K/Akt pathways, inhibited GSK-3β, induced Nrf2 nuclear translocation, augmented antioxidant responsive element enhancer activity, upregulated heme oxygenase 1 (HO-1) expression and activity, and provided protective effects against Aβ 25–35 -induced neurotoxicity, including oxidative stress, apoptosis, and autophagic cell death. In conclusion, GP-17 conferred protection against Aβ 25–35 -induced neurotoxicity through estrogen receptor-dependent activation of PI3K/Akt pathways, inactivation of GSK-3β and activation of Nrf2/ARE/HO-1 pathways. This finding might provide novel insights into understanding the mechanism for neuroprotective effects of phytoestrogens or gypenosides

  20. Effects of Nrf2 Deficiency on Bone Microarchitecture in an Experimental Model of Osteoporosis

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    Lidia Ibáñez

    2014-01-01

    Full Text Available Objective. Redox imbalance contributes to bone fragility. We have evaluated the in vivo role of nuclear factor erythroid derived 2-related factor-2 (Nrf2, an important regulator of cellular responses to oxidative stress, in bone metabolism using a model of postmenopausal osteoporosis. Methods. Ovariectomy was performed in both wild-type and mice deficient in Nrf2 (Nrf2−/−. Bone microarchitecture was analyzed by μCT. Serum markers of bone metabolism were also measured. Reactive oxygen species production was determined using dihydrorhodamine 123. Results. Sham-operated or ovariectomized Nrf2−/− mice exhibit a loss in trabecular bone mineral density in femur, accompanied by a reduction in cortical area in vertebrae. Nrf2 deficiency tended to increase osteoblastic markers and significantly enhanced osteoclastic markers in sham-operated animals indicating an increased bone turnover with a main effect on bone resorption. We have also shown an increased production of oxidative stress in bone marrow-derived cells from sham-operated or ovariectomized Nrf2−/− mice and a higher responsiveness of bone marrow-derived cells to osteoclastogenic stimuli in vitro. Conclusion. We have demonstrated in vivo a key role of Nrf2 in the maintenance of bone microarchitecture.

  1. Enhanced sensitivity of A549 cells to the cytotoxic action of anticancer drugs via suppression of Nrf2 by procyanidins from Cinnamomi Cortex extract

    Energy Technology Data Exchange (ETDEWEB)

    Ohnuma, Tomokazu; Matsumoto, Takashi; Itoi, Ayano; Kawana, Ayako; Nishiyama, Takahito; Ogura, Kenichiro [Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji-shi, Tokyo 192-0392 (Japan); Hiratsuka, Akira, E-mail: hiratuka@toyaku.ac.jp [Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji-shi, Tokyo 192-0392 (Japan)

    2011-10-07

    Highlights: {yields} We found a novel inhibitor of Nrf2 known as a chemoresistance factor. {yields} Overexpressed Nrf2 in lung cancer cells was suppressed by Cinnamomi Cortex extract. {yields} Cytotoxic action of anticancer drugs in cells treated with the extract was enhanced. {yields} Procyanidin tetramers and pentamers were active components in suppressing Nrf2. -- Abstract: Nuclear factor-E2-related factor 2 (Nrf2) is an important cytoprotective transcription factor because Nrf2-regulated enzymes play a key role in antioxidant and detoxification processes. Recent studies have reported that lung cancer cells overexpressing Nrf2 exhibit increased resistance to chemotherapy. Suppression of overexpressed Nrf2 is needed for a new therapeutic approach against lung cancers. In the present study, we found that Cinnamomi Cortex extract (CCE) has an ability to suppress Nrf2-regulated enzyme activity and Nrf2 expression in human lung cancer A549 cells with high Nrf2 activity. Moreover, we demonstrated that CCE significantly enhances sensitivity of A549 cells to the cytotoxic action of doxorubicin and etoposide as well as increasing the intracellular accumulation of both drugs. These results suggest that CCE might be an effective concomitant agent to reduce anticancer drug resistance derived from Nrf2 overexpression. Bioactivity-guided fractionation revealed that procyanidin tetramers and pentamers contained in CCE were active components in suppressing Nrf2.

  2. Curcumin attenuates insulin resistance in hepatocytes by inducing Nrf2 nuclear translocation.

    Science.gov (United States)

    Zhao, Shu-Guang; Li, Qiang; Liu, Zhen-Xiong; Wang, Jing-Jie; Wang, Xv-Xia; Qin, Ming; Wen, Qin-Sheng

    2011-01-01

    NF-E2-Related Factor-2 (Nrf2) is a transcription factor that plays a crucial role in the cellular protection against oxidative stress. Curcumin has been reported to induce Nrf2 nuclear translocation and upregulate the expression of numerous reactive oxygen species (ROS) detoxifying and antioxidant genes in hepatocytes. This study was designed to investigate whether curcumin-induced Nrf2 nuclear translocation could reduce ROS-mediated insulin resistance in cultured LO2 hepatocytes. Human LO2 hepatocytes were incubated with curcumine and glucose oxidase (GO) in the presence/absence of wortmannin (a phosphatidyinositol 3-kinase (PI3K) inhibitor), oxidative stress, cellular damage, Nrf2 nuclear translocation and insulin resistance were measured. GO exposure significantly increased intracellular ROS, glutathione (GSH) depletion, malondialdehyde (MDA) formation, and increased activities of cellular lactate dehydrogenase (LDH) and aspartate amino transferase (AST), as well as causing insulin resistance. Curcumin pretreatment significantly attenuated these disturbances in intracellular ROS, liver enzyme activity and significantly antagonized the lipid peroxidation, GSH depletion and insulin resistance induced by GO in LO2 hepatocytes. These effects paralleled Nrf2 nuclear translocation induced by curcumin. Wortmannin partially blocked curcumin-induced Nrf2 nuclear translocation. In addition, wortmannin prevented curcumin-induced improvements in intracellular ROS, MDA formation, GSH depletion, liver enzyme activity and insulin resistance in cultured LO2 hepatocytes. These findings suggest that curcumin could reduce ROS-mediated insulin resistance in hepatocytes, at least in part through nuclear translocation of Nrf2.

  3. Acceleration of UVB-induced photoageing in nrf2 gene-deficient mice.

    Science.gov (United States)

    Hirota, Ayako; Kawachi, Yasuhiro; Yamamoto, Masayuki; Koga, Tsutomu; Hamada, Kazuhiko; Otsuka, Fujio

    2011-08-01

    Ultraviolet (UV) radiation is one of the most important environmental factors involved in the pathogenesis of premature skin ageing, termed photoageing. The harmful effects of UV in photoageing are associated with the generation of reactive oxygen species, and cellular antioxidants act to prevent the occurrence and reduce the severity of UV-induced photoageing. The transcription factor Nrf2 and its cytoplasmic anchor protein, Keap1, are central regulators of the cellular antioxidant response. Here, we investigated the role of the Nrf2-Keap1 pathway in photoageing using nrf2 gene-deficient (nrf2(-/-)) mice. Our results indicated that UVB-irradiated nrf2(-/-) mice showed accelerated photoageing, such as coarse wrinkle formation, loss of skin flexibility, epidermal thickening and deposition of extracellular matrix in the upper dermis. In addition, nrf2(-/-) mice also showed an increase in cutaneous reactivity for the lipid peroxidation product 4-hydroxy-2-nonenal and a significant decrease in cutaneous glutathione level. These findings indicate that Nrf2 plays the important role in the protection against UVB-induced photoageing. © 2011 John Wiley & Sons A/S.

  4. Nrf2 activators as potential modulators of injury in human kidney cells

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    Amandla Atilano-Roque

    2016-01-01

    Full Text Available Cisplatin is a chemotherapeutic agent used in the treatment of solid tumors, with clinical use often complicated by kidney toxicity. Nuclear factor (erythroid-derived-2-like 2 (Nrf2 is a transcription factor involved in kidney protectant effects. The purpose of this study was to determine whether the Nrf2 activators oltipraz, sulforaphane, and oleanolic acid could protect human kidney cells against cisplatin-induced injury and to compare the protective effects between three Nrf2 activators. Human proximal tubule cells (hPTC and human embryonic kidney 293 cells (HEK293 were exposed to cisplatin doses in the absence and presence of Nrf2 activators. Pre- and delayed-cisplatin and Nrf2 activator exposures were also assessed. Cell viability was enhanced with Nrf2 activator exposures, with differences detected between pre- and delayed-treatments. Both sulforaphane and oltipraz increased the expression of anti-oxidant genes GCLC and NQO1. These findings suggest potential human kidney protective benefits of Nrf2 activators with planned exposures to cisplatin.

  5. Curcumin Pretreatment Induces Nrf2 and an Antioxidant Response and Prevents Hemin-Induced Toxicity in Primary Cultures of Cerebellar Granule Neurons of Rats

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    Susana González-Reyes

    2013-01-01

    Full Text Available Curcumin is a bifunctional antioxidant derived from Curcuma longa. This study identifies curcumin as a neuroprotectant against hemin-induced damage in primary cultures of cerebellar granule neurons (CGNs of rats. Hemin, the oxidized form of heme, is a highly reactive compound that induces cellular injury. Pretreatment of CGNs with 5–30 μM curcumin effectively increased by 2.3–4.9 fold heme oxygenase-1 (HO-1 expression and by 5.6–14.3-fold glutathione (GSH levels. Moreover, 15 μM curcumin attenuated by 55% the increase in reactive oxygen species (ROS production, by 94% the reduction of GSH/glutathione disulfide (GSSG ratio, and by 49% the cell death induced by hemin. The inhibition of heme oxygenase system or GSH synthesis with tin mesoporphyrin and buthionine sulfoximine, respectively, suppressed the protective effect of curcumin against hemin-induced toxicity. These data strongly suggest that HO-1 and GSH play a major role in the protective effect of curcumin. Furthermore, it was found that 24 h of incubation with curcumin increases by 1.4-, 2.3-, and 5.2-fold the activity of glutathione reductase, glutathione S-transferase and superoxide dismutase, respectively. Additionally, it was found that curcumin was capable of inducing nuclear factor (erythroid-derived 2-like 2 (Nrf2 translocation into the nucleus. These data suggest that the pretreatment with curcumin induces Nrf2 and an antioxidant response that may play an important role in the protective effect of this antioxidant against hemin-induced neuronal death.

  6. Nrf2 protects photoreceptor cells from photo-oxidative stress induced by blue light.

    Science.gov (United States)

    Chen, Wan-Ju; Wu, Caiying; Xu, Zhenhua; Kuse, Yoshiki; Hara, Hideaki; Duh, Elia J

    2017-01-01

    Oxidative stress plays a key role in age-related macular degeneration and hereditary retinal degenerations. Light damage in rodents has been used extensively to model oxidative stress-induced photoreceptor degeneration, and photo-oxidative injury from blue light is particularly damaging to photoreceptors. The endogenous factors protecting photoreceptors from oxidative stress, including photo-oxidative stress, are continuing to be elucidated. In this study, we evaluated the effect of blue light exposure on photoreceptors and its relationship to Nrf2 using cultured murine photoreceptor (661W) cells. 661W cells were exposed to blue light at 2500 lux. Exposure to blue light for 6-24 h resulted in a significant increase in intracellular reactive oxygen species (ROS) and death of 661W cells in a time-dependent fashion. Blue light exposure resulted in activation of Nrf2, as indicated by an increase in nuclear translocation of Nrf2. This was associated with a significant induction of expression of Nrf2 as well as an array of Nrf2 target genes, including antioxidant genes, as indicated by quantitative reverse transcription PCR (qRT-PCR). In order to determine the functional role of Nrf2, siRNA-mediated knockdown studies were performed. Nrf2-knockdown in 661W cells resulted in significant exacerbation of blue light-induced reactive oxygen species levels as well as cell death. Taken together, these findings indicate that Nrf2 is an important endogenous protective factor against oxidative stress in photoreceptor cells. This suggests that drugs targeting Nrf2 could be considered as a neuroprotective strategy for photoreceptors in AMD and other retinal conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. ABCF2, an Nrf2 target gene, contributes to cisplatin resistance in ovarian cancer cells.

    Science.gov (United States)

    Bao, Lingjie; Wu, Jianfa; Dodson, Matthew; Rojo de la Vega, Elisa Montserrat; Ning, Yan; Zhang, Zhenbo; Yao, Ming; Zhang, Donna D; Xu, Congjian; Yi, Xiaofang

    2017-06-01

    Previously, we have demonstrated that NRF2 plays a key role in mediating cisplatin resistance in ovarian cancer. To further explore the mechanism underlying NRF2-dependent cisplatin resistance, we stably overexpressed or knocked down NRF2 in parental and cisplatin-resistant human ovarian cancer cells, respectively. These two pairs of stable cell lines were then subjected to microarray analysis, where we identified 18 putative NRF2 target genes. Among these genes, ABCF2, a cytosolic member of the ABC superfamily of transporters, has previously been reported to contribute to chemoresistance in clear cell ovarian cancer. A detailed analysis on ABCF2 revealed a functional antioxidant response element (ARE) in its promoter region, establishing ABCF2 as an NRF2 target gene. Next, we investigated the contribution of ABCF2 in NRF2-mediated cisplatin resistance using our stable ovarian cancer cell lines. The NRF2-overexpressing cell line, containing high levels of ABCF2, was more resistant to cisplatin-induced apoptosis compared to its control cell line; whereas the NRF2 knockdown cell line with low levels of ABCF2, was more sensitive to cisplatin treatment than its control cell line. Furthermore, transient overexpression of ABCF2 in the parental cells decreased apoptosis and increased cell viability following cisplatin treatment. Conversely, knockdown of ABCF2 using specific siRNA notably increased apoptosis and decreased cell viability in cisplatin-resistant cells treated with cisplatin. This data indicate that the novel NRF2 target gene, ABCF2, plays a critical role in cisplatin resistance in ovarian cancer, and that targeting ABCF2 may be a new strategy to improve chemotherapeutic efficiency. © 2017 Wiley Periodicals, Inc.

  8. Stabilization of Nrf2 protein by D3T provides protection against ethanol-induced apoptosis in PC12 cells.

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    Jian Dong

    2011-02-01

    Full Text Available Previous studies have demonstrated that maternal ethanol exposure induces a moderate increase in Nrf2 protein expression in mouse embryos. Pretreatment with the Nrf2 inducer, 3H-1, 2-dithiole-3-thione (D3T, significantly increases the Nrf2 protein levels and prevents apoptosis in ethanol-exposed embryos. The present study, using PC12 cells, was designed to determine whether increased Nrf2 stability is a mechanism by which D3T enhances Nrf2 activation and subsequent antioxidant protection. Ethanol and D3T treatment resulted in a significant accumulation of Nrf2 protein in PC 12 cells. CHX chase analysis has shown that ethanol treatment delayed the degradation of Nrf2 protein in PC12 cells. A significantly greater decrease in Nrf2 protein degradation was observed in the cells treated with D3T alone or with both ethanol and D3T. In addition, D3T treatment significantly reduced ethanol-induced apoptosis. These results demonstrate that the stabilization of Nrf2 protein by D3T confers protection against ethanol-induced apoptosis.

  9. Effects of Glycyrrhetinic Acid on GSH Synthesis Induced by Realgar in the Mouse Hippocampus: Involvement of System [Formula: see text], System [Formula: see text], MRP-1, and Nrf2.

    Science.gov (United States)

    Wang, Yan-Lei; Chen, Mo; Huo, Tao-Guang; Zhang, Ying-Hua; Fang, Ying; Feng, Cong; Wang, Shou-Yun; Jiang, Hong

    2017-05-01

    Realgar, a type of mineral drug-containing arsenic, exhibits neurotoxicity. Brain glutathione (GSH) is crucial to protect the nervous system and to resist arsenic toxicity. Therefore, the main aim of this study was to explore the neurotoxic mechanisms of realgar and the protective effects of glycyrrhetinic acid (GA) by observing the effects of GA on the hippocampal GSH biosynthetic pathway after exposure to realgar. Institute of Cancer Research (ICR) mice were randomly divided into five groups: a control group, a GA control group, a realgar alone group, a low-dose GA intervention group, and a high-dose GA intervention group. Cognitive ability was tested using an object recognition task (ORT). The ultrastructures of the hippocampal neurons and synapses were observed. mRNA and protein levels of EAAT1, EAAT2, EAAT3, xCT, Nrf2, HO-1, γ-GCS (GCLC, GCLM), and MRP-1 were measured, as was the cellular localization of EAAT3, xCT, MRP-1, and Nrf2. The levels of GSH in the hippocampus, the levels of glutamate (Glu) and cysteine (Cys) in the extracellular fluid of hippocampal CA1 region, and the levels of active sulfur in the brain were also investigated. The results indicate that realgar lowered hippocampal GSH levels, resulting in ultrastructural changes in hippocampal neurons and synapses and deficiencies in cognitive ability, ultimately inducing neurotoxicity. GA could trigger the expression of Nrf2, HO-1, EAAT1, EAAT2, EAAT3, xCT, MRP-1, GCLC, and GCLM. Additionally, the expression of γ-GT and the supply levels of Glu and Cys increased, ultimately causing a significant increase in hippocampal GSH to alleviate realgar-induced neurotoxicity. In conclusion, the findings from our study indicate that GA can antagonize decreased brain GSH levels induced by realgar and can lessen the neurotoxicity of realgar.

  10. The NRF2 Activation and Antioxidative Response Are Not Impaired Overall during Hyperoxia-Induced Lung Epithelial Cell Death

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    Haranatha R. Potteti

    2013-01-01

    Full Text Available Lung epithelial and endothelial cell death caused by pro-oxidant insults is a cardinal feature of acute lung injury/acute respiratory distress syndrome (ALI/ARDS patients. The NF-E2-related factor 2 (NRF2 activation in response to oxidant exposure is crucial to the induction of several antioxidative and cytoprotective enzymes that mitigate cellular stress. Since prolonged exposure to hyperoxia causes cell death, we hypothesized that chronic hyperoxia impairs NRF2 activation, resulting in cell death. To test this hypothesis, we exposed nonmalignant small airway epithelial cells (AECs to acute (1–12 h and chronic (36–48 h hyperoxia and evaluated cell death, NRF2 nuclear accumulation and target gene expression, and NRF2 recruitment to the endogenous HMOX1 and NQO1 promoters. As expected, hyperoxia gradually induced death in AECs, noticeably and significantly by 36 h; ~60% of cells were dead by 48 h. However, we unexpectedly found increased expression levels of NRF2-regulated antioxidative genes and nuclear NRF2 in AECs exposed to chronic hyperoxia as compared to acute hyperoxia. Chromatin Immunoprecipitation (ChIP assays revealed an increased recruitment of NRF2 to the endogenous HMOX1 and NQO1 promoters in AECs exposed to acute or chronic hyperoxia. Thus, our findings demonstrate that NRF2 activation and antioxidant gene expression are functional during hyperoxia-induced lung epithelial cell death and that chronic hyperoxia does not impair NRF2 signaling overall.

  11. Nrf2-AKT interactions regulate heme oxygenase 1 expression in kidney epithelia during hypoxia and hypoxia-reoxygenation.

    Science.gov (United States)

    Potteti, Haranatha R; Tamatam, Chandramohan R; Marreddy, Rakesh; Reddy, Narsa M; Noel, Sanjeev; Rabb, Hamid; Reddy, Sekhar P

    2016-11-01

    Ischemia-reperfusion (IR)-induced kidney injury is a major clinical problem, but its underlying mechanisms remain unclear. The transcription factor known as nuclear factor, erythroid 2-like 2 (NFE2L2 or Nrf2) is crucial for protection against oxidative stress generated by pro-oxidant insults. We have previously shown that Nrf2 deficiency enhances susceptibility to IR-induced kidney injury in mice and that its upregulation is protective. Here, we examined Nrf2 target antioxidant gene expression and the mechanisms of its activation in both human and murine kidney epithelia following acute (2 h) and chronic (12 h) hypoxia and reoxygenation conditions. We found that acute hypoxia modestly stimulates and chronic hypoxia strongly stimulates Nrf2 putative target HMOX1 expression, but not that of other antioxidant genes. Inhibition of AKT1/2 or ERK1/2 signaling blocked this induction; AKT1/2 but not ERK1/2 inhibition affected Nrf2 levels in basal and acute hypoxia-reoxygenation states. Unexpectedly, chromatin immunoprecipitation assays revealed reduced levels of Nrf2 binding at the distal AB1 and SX2 enhancers and proximal promoter of HMOX1 in acute hypoxia, accompanied by diminished levels of nuclear Nrf2. In contrast, Nrf2 binding at the AB1 and SX2 enhancers significantly but differentially increased during chronic hypoxia and reoxygenation, with reaccumulation of nuclear Nrf2 levels. Small interfering-RNA-mediated Nrf2 depletion attenuated acute and chronic hypoxia-inducible HMOX1 expression, and primary Nrf2-null kidney epithelia showed reduced levels of HMOX1 induction in response to both acute and chronic hypoxia. Collectively, our data demonstrate that Nrf2 upregulates HMOX1 expression in kidney epithelia through a distinct mechanism during acute and chronic hypoxia reoxygenation, and that both AKT1/2 and ERK1/2 signaling are required for this process. Copyright © 2016 the American Physiological Society.

  12. Nrf2 mediates redox adaptation in NOX4-overexpressed non-small cell lung cancer cells

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    Wu, Qipeng; Yao, Bei; Li, Ning; Ma, Lei; Deng, Yanchao; Yang, Yang; Zeng, Cheng; Yang, Zhicheng [Department of Clinical Pharmacy, School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006 (China); Liu, Bing, E-mail: liubing520@gdpu.edu.cn [Department of Clinical Pharmacy, School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006 (China); Guangdong Key Laboratory of Pharmaceutical Bioactive Substances, Guangdong Pharmaceutical University, Guangzhou 510006 (China)

    2017-03-15

    The redox adaptation mechanisms in cancer cells are very complex and remain largely unclear. Our previous studies have confirmed that NADPH oxidase 4 (NOX4) is abundantly expressed in non-small cell lung cancer (NSCLC) and confers apoptosis resistance on NSCLC cells. However, the comprehensive mechanisms for NOX4-mediated oxidative resistance of cancer cells remain still undentified. The present study found that NOX4-derived H{sub 2}O{sub 2} enhanced the nuclear factor erythroid 2-related factor 2 (Nrf2) stability via disruption of redox-dependent proteasomal degradation and stimulated its activity through activation of PI3K signaling. Specifically, the results showed that ectopic NOX4 expression did not induce apoptosis of A549 cells; however, inhibition of Nrf2 resulted in obvious apoptotic death of NOX4-overexpressed A549 cells, accompanied by a significant increase in H{sub 2}O{sub 2} level and decrease in GSH content. Besides, inhibition of Nrf2 could suppress cell growth and efficiently reverse the enhancement effect of NOX4 on cell growth. The in vivo data confirmed that inhibition of Nrf2 could interfere apoptosis resistance in NOX4-overexpressed A549 tumors and led to cell growth inhibition. In conclusion, these results reveal that Nrf2 is critically involved in redox adaptation regulation in NOX4-overexpressed NSCLC cells. Therefore, NOX4 and Nrf2 may be promising combination targets against malignant progression of NSCLC. - Highlights: • NOX4-derived H{sub 2}O{sub 2} upregulates Nrf2 expression and activity in NSCLC. • Nrf2 confers apoptosis resistance in NOX4-overexpressed NSCLC cells. • Inhibition of Nrf2 reverses the enhancement effect of NOX4 on cell growth.

  13. Constitutive activation of Nrf2 induces a stable reductive state in the mouse myocardium

    Directory of Open Access Journals (Sweden)

    Gobinath Shanmugam

    2017-08-01

    Full Text Available Redox homeostasis regulates key cellular signaling pathways in both physiology and pathology. The cell's antioxidant response provides a defense against oxidative stress and establishes a redox tone permissive for cell signaling. The molecular regulation of the well-known Keap1/Nrf2 system acts as sensor responding to changes in redox homeostasis and is poorly studied in the heart. Importantly, it is not yet known whether Nrf2 alone can serve as a master regulator of cellular redox homeostasis without compensation of the transcriptional regulation of antioxidant response element (ARE genes through alternate mechanisms. Here, we addressed this question using cardiac-specific transgenic expression at two different levels of constitutively active nuclear erythroid related factor 2 (caNrf2 functioning independently of Keap1. The caNrf2 mice showed augmentation of glutathione (GSH, the key regulator of the cellular thiol redox state. The Trans-AM assay for Nrf2-binding to the antioxidant response element (ARE showed a dose-dependent increase associated with upregulation of several major antioxidant genes and proteins. This was accompanied by a significant decrease in dihydroethidium staining and malondialdehyde (MDA in the caNrf2-TG mice myocardium. Interestingly, caNrf2 gene-dosage dependent redox changes were noted resulting in generation of a multi-stage model of pro-reductive and reductive conditions in the myocardium of TG-low and TG-high mice, respectively. These data clearly show that Nrf2 levels alone are capable of serving as the master regulator of the ARE. These models provide an important platform to investigate the impact of the Nrf2 system independent of the need to regulate the activity of Keap1 and the consequent exposure to pro-oxidants or electrophiles, which have numerous off-target effects.

  14. Nrf2 Activation Protects against Solar-Simulated Ultraviolet Radiation in Mice and Humans.

    Science.gov (United States)

    Knatko, Elena V; Ibbotson, Sally H; Zhang, Ying; Higgins, Maureen; Fahey, Jed W; Talalay, Paul; Dawe, Robert S; Ferguson, James; Huang, Jeffrey T-J; Clarke, Rosemary; Zheng, Suqing; Saito, Akira; Kalra, Sukirti; Benedict, Andrea L; Honda, Tadashi; Proby, Charlotte M; Dinkova-Kostova, Albena T

    2015-06-01

    The transcription factor Nrf2 determines the ability to adapt and survive under conditions of electrophilic, oxidative, and inflammatory stress by regulating the expression of elaborate networks comprising nearly 500 genes encoding proteins with versatile cytoprotective functions. In mice, disruption of Nrf2 increases susceptibility to carcinogens and accelerates disease pathogenesis. Paradoxically, Nrf2 is upregulated in established human tumors, but whether this upregulation drives carcinogenesis is not known. Here we show that the incidence, multiplicity, and burden of solar-simulated UV radiation-mediated cutaneous tumors that form in SKH-1 hairless mice in which Nrf2 is genetically constitutively activated are lower than those that arise in their wild-type counterparts. Pharmacologic Nrf2 activation by topical biweekly applications of small (40 nmol) quantities of the potent bis(cyano enone) inducer TBE-31 has a similar protective effect against solar-simulated UV radiation in animals receiving long-term treatment with the immunosuppressive agent azathioprine. Genetic or pharmacologic Nrf2 activation lowers the expression of the pro-inflammatory factors IL6 and IL1β, and COX2 after acute exposure of mice to UV radiation. In healthy human subjects, topical applications of extracts delivering the Nrf2 activator sulforaphane reduced the degree of solar-simulated UV radiation-induced skin erythema, a quantifiable surrogate endpoint for cutaneous damage and skin cancer risk. Collectively, these data show that Nrf2 is not a driver for tumorigenesis even upon exposure to a very potent and complete carcinogen and strongly suggest that the frequent activation of Nrf2 in established human tumors is a marker of metabolic adaptation. ©2015 American Association for Cancer Research.

  15. Nrf2 mediates redox adaptation in NOX4-overexpressed non-small cell lung cancer cells

    International Nuclear Information System (INIS)

    Wu, Qipeng; Yao, Bei; Li, Ning; Ma, Lei; Deng, Yanchao; Yang, Yang; Zeng, Cheng; Yang, Zhicheng; Liu, Bing

    2017-01-01

    The redox adaptation mechanisms in cancer cells are very complex and remain largely unclear. Our previous studies have confirmed that NADPH oxidase 4 (NOX4) is abundantly expressed in non-small cell lung cancer (NSCLC) and confers apoptosis resistance on NSCLC cells. However, the comprehensive mechanisms for NOX4-mediated oxidative resistance of cancer cells remain still undentified. The present study found that NOX4-derived H 2 O 2 enhanced the nuclear factor erythroid 2-related factor 2 (Nrf2) stability via disruption of redox-dependent proteasomal degradation and stimulated its activity through activation of PI3K signaling. Specifically, the results showed that ectopic NOX4 expression did not induce apoptosis of A549 cells; however, inhibition of Nrf2 resulted in obvious apoptotic death of NOX4-overexpressed A549 cells, accompanied by a significant increase in H 2 O 2 level and decrease in GSH content. Besides, inhibition of Nrf2 could suppress cell growth and efficiently reverse the enhancement effect of NOX4 on cell growth. The in vivo data confirmed that inhibition of Nrf2 could interfere apoptosis resistance in NOX4-overexpressed A549 tumors and led to cell growth inhibition. In conclusion, these results reveal that Nrf2 is critically involved in redox adaptation regulation in NOX4-overexpressed NSCLC cells. Therefore, NOX4 and Nrf2 may be promising combination targets against malignant progression of NSCLC. - Highlights: • NOX4-derived H 2 O 2 upregulates Nrf2 expression and activity in NSCLC. • Nrf2 confers apoptosis resistance in NOX4-overexpressed NSCLC cells. • Inhibition of Nrf2 reverses the enhancement effect of NOX4 on cell growth.

  16. Nrf2 is required to maintain the self-renewal of glioma stem cells

    International Nuclear Information System (INIS)

    Zhu, Jianhong; Wang, Handong; Sun, Qing; Ji, Xiangjun; Zhu, Lin; Cong, Zixiang; Zhou, Yuan; Liu, Huandong; Zhou, Mengliang

    2013-01-01

    Glioblastomas are deadly cancers that display a functional cellular hierarchy maintained by self-renewing glioma stem cells (GSCs). Self-renewal is a complex biological process necessary for maintaining the glioma stem cells. Nuclear factor rythroid 2-related factor 2(Nrf2) plays a significant role in protecting cells from endogenous and exogenous stresses. Nrf2 is a key nuclear transcription factor that regulates antioxidant response element (ARE)-containing genes. Previous studies have demonstrated the significant role of Nrf2 in the proliferation of glioblastoma, and in their resistance to radioactive therapies. We examined the effect of knocking down Nrf2 in GSCs. Nrf2 expression was down-regulated by shRNA transinfected with lentivirus. Expression levels of Nestin, Nrf2, BMI-1, Sox2 and Cyclin E were assessed by western blotting, quantitative polymerase chain reaction (qPCR) and immunohistochemistry analysis. The capacity for self-renewal in vitro was assessed by genesis of colonies. The capacity for self-renewal in vivo was analyzed by tumor genesis of xenografts in nude mice. Knockdown of Nrf2 inhibited the proliferation of GSCs, and significantly reduced the expression of BMI-1, Sox2 and CyclinE. Knocking down of Nrf2 changed the cell cycle distribution of GSCs by causing an uncharacteristic increase in the proportion of cells in the G2 phase and a decrease in the proportion of cells in the S phase of the cell cycle. Nrf2 is required to maintain the self-renewal of GSCs, and its down-regulation can attenuate the self-renewal of GSCs significantly

  17. Luteolin and Apigenin Attenuate 4-Hydroxy-2-Nonenal-Mediated Cell Death through Modulation of UPR, Nrf2-ARE and MAPK Pathways in PC12 Cells

    Science.gov (United States)

    Wu, Pei-Shan; Yen, Jui-Hung; Kou, Mei-Chun; Wu, Ming-Jiuan

    2015-01-01

    Luteolin and apigenin are dietary flavones and exhibit a broad spectrum of biological activities including antioxidant, anti-inflammatory, anti-cancer and neuroprotective effects. The lipid peroxidation product 4-hydroxy-2-nonenal (4-HNE) has been implicated as a causative agent in the development of neurodegenerative disorders. This study investigates the cytoprotective effects of luteolin and apigenin against 4-HNE-mediated cytotoxicity in neuronal-like catecholaminergic PC12 cells. Both flavones restored cell viability and repressed caspase-3 and PARP-1 activation in 4-HNE-treated cells. Luteolin also mitigated 4-HNE-mediated LC3 conversion and reactive oxygen species (ROS) production. Luteolin and apigenin up-regulated 4-HNE-mediated unfolded protein response (UPR), leading to an increase in endoplasmic reticulum chaperone GRP78 and decrease in the expression of UPR-targeted pro-apoptotic genes. They also induced the expression of Nrf2-targeted HO-1 and xCT in the absence of 4-HNE, but counteracted their expression in the presence of 4-HNE. Moreover, we found that JNK and p38 MAPK inhibitors significantly antagonized the increase in cell viability induced by luteolin and apigenin. Consistently, enhanced phosphorylation of JNK and p38 MAPK was observed in luteolin- and apigenin-treated cells. In conclusion, this result shows that luteolin and apigenin activate MAPK and Nrf2 signaling, which elicit adaptive cellular stress response pathways, restore 4-HNE-induced ER homeostasis and inhibit cytotoxicity. Luteolin exerts a stronger cytoprotective effect than apigenin possibly due to its higher MAPK, Nrf2 and UPR activation, and ROS scavenging activity. PMID:26087007

  18. Oxidative Stress in Cardiovascular Diseases: Involvement of Nrf2 Antioxidant Redox Signaling in Macrophage Foam Cells Formation

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    Bee Kee Ooi

    2017-11-01

    Full Text Available Oxidative stress is an important risk factor contributing to the pathogenesis of cardiovascular diseases. Oxidative stress that results from excessive reactive oxygen species (ROS production accounts for impaired endothelial function, a process which promotes atherosclerotic lesion or fatty streaks formation (foam cells. Nuclear factor erythroid 2-related factor 2 (Nrf2 is a transcription factor involved in cellular redox homeostasis. Upon exposure to oxidative stress, Nrf2 is dissociated from its inhibitor Keap-1 and translocated into the nucleus, where it results in the transcriptional activation of cell defense genes. Nrf2 has been demonstrated to be involved in the protection against foam cells formation by regulating the expression of antioxidant proteins (HO-1, Prxs, and GPx1, ATP-binding cassette (ABC efflux transporters (ABCA1 and ABCG1 and scavenger receptors (scavenger receptor class B (CD36, scavenger receptor class A (SR-A and lectin-type oxidized LDL receptor (LOX-1. However, Nrf2 has also been reported to exhibit pro-atherogenic effects. A better understanding on the mechanism of Nrf2 in oxidative stress-induced cardiac injury, as well as the regulation of cholesterol uptake and efflux, are required before it can serve as a novel therapeutic target for cardiovascular diseases prevention and treatment.

  19. Clopidogrel Protects Endothelium by Hindering TNFα-Induced VCAM-1 Expression through CaMKKβ/AMPK/Nrf2 Pathway

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    Huabing Yang

    2016-01-01

    Full Text Available Clopidogrel (INN, an oral antiplatelet drug, has been revealed to have a number of biological properties, for instance, anti-inflammation and antioxidation. Oxidative stress plays an imperative role in inflammation, diabetes mellitus, atherosclerosis, and cancer. In the present study, human aortic endothelial cells (HAECs were employed to explore the anti-inflammatory activity of INN. INN reduced TNFα-induced reactive oxygen species (ROS generation and time-dependently prompted the expression and activity of heme oxygenase 1 (HO-1. Cellular glutathione (GSH levels were augmented by INN. shHO-1 blocked the INN suppression of TNFα-induced HL-60 cell adhesion. The CaMKKβ/AMPK pathway and Nrf2 transcriptional factor were implicated in the induction of HO-1 by INN. Additionally, TNFα dramatically augmented VCAM-1 expression at protein and mRNA levels. INN treatment strikingly repressed TNFα-induced expression of VCAM-1 and HL-60 cell adhesion. Compound C, an AMPK inhibitor, and shNrf2 abolished TNFα-induced expression of VCAM-1 and HL-60 cell adhesion. Our data suggest that INN diminishes TNFα-stimulated VCAM-1 expression at least in part via HO-1 induction, which is CaMKKβ/AMPK pathway-dependent.

  20. Paeonia lactiflora Pall. protects against ANIT-induced cholestasis by activating Nrf2 via PI3K/Akt signaling pathway

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    Ma X

    2015-09-01

    -cysteine ligase catalytic subunit (GCLc, glutamate-cysteine ligase modulatory subunit (GCLm, Akt, heme oxygenase-1 (HO-1, NAD(PH/quinone oxidoreductase 1 (Nqo1, and Nrf2 were further analyzed. In addition, validation of PLP putative target network was also performed in silico. Results: Four major compounds including paeoniflorin, albiflorin, oxypaeoniflorin, and benzoylpaeoniflorin were identified by LC-MS analysis in water extract of PLP. Moreover, PLP could remarkably downregulate serum levels of TBIL, DBIL, AST, ALT, ALP, γ-GT, and TBA, and alleviate the histological damage of liver tissue caused by ANIT. It enhanced antioxidative system by activating PI3K/Akt/Nrf2 pathway through increasing Akt, Nrf2, HO-1, Nqo1, GCLc, and GCLm expression. The putative targets network validation also confirmed the important role of PLP in activating Akt expression. Conclusion: The potential mechanism of PLP in alleviating ANIT-induced cholestasis could to be related to the induction of GSH synthesis by activating Nrf2 through PI3K/Akt-dependent pathway. This indicates that PLP might be a potential therapeutic agent for cholestasis. Keywords: Paeonia lactiflora Pall., cholestatic hepatitis, antioxidation, Nrf2, Akt

  1. RNAi Screen for NRF2 Inducers Identifies Targets That Rescue Primary Lung Epithelial Cells from Cigarette Smoke Induced Radical Stress.

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    Frances-Rose Schumacher

    Full Text Available Chronic Obstructive Pulmonary Disease (COPD is a highly prevalent condition characterized by inflammation and progressive obstruction of the airways. At present, there is no treatment that suppresses the chronic inflammation of the disease, and COPD patients often succumb to the condition. Excessive oxidative stress caused by smoke inhalation is a major driving force of the disease. The transcription factor NRF2 is a critical player in the battle against oxidative stress and its function is impaired in COPD. Increasing NRF2 activity may therefore be a viable therapeutic option for COPD treatment. We show that down regulation of KEAP1, a NRF2 inhibitor, protects primary human lung epithelial cells from cigarette-smoke-extract (CSE induced cell death in an established in vitro model of radical stress. To identify new potential drug targets with a similar effect, we performed a siRNA screen of the 'druggable' genome using a NRF2 transcriptional reporter cell line. This screen identified multiple genes that when down regulated increased NRF2 transcriptional activity and provided a survival benefit in the in vitro model. Our results suggest that inhibiting components of the ubiquitin-proteasome system will have the strongest effects on NRF2 transcriptional activity by increasing NRF2 levels. We also find that down regulation of the small GTPase Rab28 or the Estrogen Receptor ESRRA provide a survival benefit. Rab28 knockdown increased NRF2 protein levels, indicating that Rab28 may regulate NRF2 proteolysis. Conversely ESRRA down regulation increased NRF2 transcriptional activity without affecting NRF2 levels, suggesting a proteasome-independent mechanism.

  2. Eriodictyol Protects Endothelial Cells against Oxidative Stress-Induced Cell Death through Modulating ERK/Nrf2/ARE-Dependent Heme Oxygenase-1 Expression.

    Science.gov (United States)

    Lee, Seung Eun; Yang, Hana; Son, Gun Woo; Park, Hye Rim; Park, Cheung-Seog; Jin, Young-Ho; Park, Yong Seek

    2015-06-26

    The pathophysiology of cardiovascular diseases is complex and may involve oxidative stress-related pathways. Eriodictyol is a flavonoid present in citrus fruits that demonstrates anti-inflammatory, anti-cancer, neurotrophic, and antioxidant effects in a range of pathophysiological conditions including vascular diseases. Because oxidative stress plays a key role in the pathogenesis of cardiovascular disease, the present study was designed to verify whether eriodictyol has therapeutic potential. Upregulation of heme oxygenase-1 (HO-1), a phase II detoxifying enzyme, in endothelial cells is considered to be helpful in cardiovascular disease. In this study, human umbilical vein endothelial cells (HUVECs) treated with eriodictyol showed the upregulation of HO-1 through extracellular-regulated kinase (ERK)/nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathways. Further, eriodictyol treatment provided protection against hydrogen peroxide-provoked cell death. This protective effect was eliminated by treatment with a specific inhibitor of HO-1 and RNA interference-mediated knockdown of HO-1 expression. These data demonstrate that eriodictyol induces ERK/Nrf2/ARE-mediated HO-1 upregulation in human endothelial cells, which is directly associated with its vascular protection against oxidative stress-related endothelial injury, and propose that targeting the upregulation of HO-1 is a promising approach for therapeutic intervention in cardiovascular disease.

  3. Cadmium induced cardiac oxidative stress in rats and its attenuation by GSP through the activation of Nrf2 signaling pathway.

    Science.gov (United States)

    Nazimabashir; Manoharan, Vaihundam; Miltonprabu, Selvaraj

    2015-12-05

    Cadmium (Cd) is one of the toxic heavy metals in the environment, which induces oxidative stress, dyslipidemia and membrane disturbances in heart. The present study was designed to evaluate the role of grape seed proanthocyanidins (GSP) against Cd induced oxidative stress mediated cardio-toxicity in rats. In this study, male Wistar rats were treated with Cd as cadmium chloride (CdCl2, 5 mg/ kg bw, PO) and pre-administered with GSP (100 mg/kg bw, PO) 90 min before the Cd intoxication for 4 weeks. Our results demonstrate a significant increase in the levels of cardiac troponins T and I (cTnT & I), cardiac serum markers, lipid peroxidative markers and plasma total cholesterol (TC), triglycerides (TG), phospholipids (PL) and free fatty acids (FFA). Cd induced oxidative stress decreased the levels of mitochondrial Krebs cycle enzymes as well as the respiratory chain enzyme activities and altered the levels of cardiac enzymatic and non-enzymatic antioxidants. The inflammatory (NF-kB, NO, TNF-α, IL-6), apoptotic markers (caspase 3, cytochrome C, Bax, Bcl-2), membrane bound ATPases and antioxidant Nrf2 (HO-1, keap1) markers were also measured in the control and experimental rats. All these alterations caused by Cd could be lessened by the pre-supplementation of GSP. The pre-administration of GSP significantly increased the activities of mitochondrial and respiratory chain enzymes, reduced the levels of cardio-oxidative stress markers in Cd-treated rats, which examines the stress stabilizing action of GSP. GSP also prevented the cytochrome C release, inhibited the caspase activation and maintained the ratio of Bcl-2/Bax by its free radical scavenging ability. Nrf2 expression was transiently increased while the impaired cardiac markers were restored near to their basal levels by the pre-treatment with GSP in Cd intoxicated rats. The cardioprotective nature of the GSP was further fortified by our light microscopic and ultra structural findings. Overall, our results suggest

  4. Keap1/Nrf2 pathway in kidney cancer : frequent methylation of KEAP1 gene promoter in clear renal cell carcinoma

    NARCIS (Netherlands)

    Fabrizio, Federico Pio; Costantini, Manuela; Copetti, Massimiliano; la Torre, Annamaria; Sparaneo, Angelo; Fontana, Andrea; Poeta, Luana; Gallucci, Michele; Sentinelli, Steno; Graziano, Paolo; Parente, Paola; Pompeo, Vincenzo; De Salvo, Laura; Simone, Giuseppe; Papalia, Rocco; Picardo, Francesco; Balsamo, Teresa; Flammia, Gerardo Paolo; Trombetta, Domenico; Pantalone, Angela; Kok, Klaas; Paranita, Ferronika; Muscarella, Lucia Anna; Fazio, Vito Michele

    2017-01-01

    The Keap1/Nrf2 pathway is a master regulator of the cellular redox state through the induction of several antioxidant defence genes implicated in chemotherapeutic drugs resistance of tumor cells. An increasing body of evidence supports a key role for Keap1/Nrf2 pathway in kidney diseases and renal

  5. Nrf2 transcription factor gene regulates basal transcription of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... The dietary additives caused a small induction of SOD2 in the Nrf2(-/-) mouse brain, ethoxyquin and kahwoel palmitate each ... to investigate this possi- bility, cytosols from the brains of Nrf2(-/-) and Nrf2(+/+) mice ... (1970) using a Bio-Rad mini-protean vertical electrophoresis kit. Typically, 20 µg proteins ...

  6. Design, synthesis, and evaluation of curcumin derivatives as Nrf2 activators and cytoprotectors against oxidative death.

    Science.gov (United States)

    Tu, Zhi-Shan; Wang, Qi; Sun, Dan-Dan; Dai, Fang; Zhou, Bo

    2017-07-07

    Activation of nuclear factor erythroid-2-related factor 2 (Nrf2) has been proven to be an effective means to prevent the development of cancer, and natural curcumin stands out as a potent Nrf2 activator and cancer chemopreventive agent. In this study, we synthesized a series of curcumin analogs by introducing the geminal dimethyl substituents on the active methylene group to find more potent Nrf2 activators and cytoprotectors against oxidative death. The geminally dimethylated and catechol-type curcumin analog (compound 3) was identified as a promising lead molecule in terms of its increased stability and cytoprotective activity against the tert-butyl hydroperoxide (t-BHP)-induced death of HepG2 cells. Mechanism studies indicate that its cytoprotective effects are mediated by activating the Nrf2 signaling pathway in the Michael acceptor- and catechol-dependent manners. Additionally, we verified by using copper and iron ion chelators that the two metal ion-mediated oxidations of compound 3 to its corresponding electrophilic o-quinone, contribute significantly to its Nrf2-dependent cytoprotection. This work provides an example of successfully designing natural curcumin-directed Nrf2 activators by a stability-increasing and proelectrophilic strategy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. Metabolism and tissue distribution of sulforaphane in Nrf2 knockout and wild-type mice.

    Science.gov (United States)

    Clarke, John D; Hsu, Anna; Williams, David E; Dashwood, Roderick H; Stevens, Jan F; Yamamoto, Masayuki; Ho, Emily

    2011-12-01

    To determine the metabolism and tissue distribution of the dietary chemoprotective agent sulforaphane following oral administration to wild-type and Nrf2 knockout (Nrf2(-/-)) mice. Male and female wild-type and Nrf2(-/-) mice were given sulforaphane (5 or 20 μmoles) by oral gavage; plasma, liver, kidney, small intestine, colon, lung, brain and prostate were collected at 2, 6 and 24 h (h). The five major metabolites of sulforaphane were measured in tissues by high performance liquid chromatography coupled with tandem mass spectrometry. Sulforaphane metabolites were detected in all tissues at 2 and 6 h post gavage, with the highest concentrations in the small intestine, prostate, kidney and lung. A dose-dependent increase in sulforaphane concentrations was observed in all tissues except prostate. At 5 μmole, Nrf2(-/-) genotype had no effect on sulforaphane metabolism. Only Nrf2(-/-) females given 20 μmoles sulforaphane for 6 h exhibited a marked increase in tissue sulforaphane metabolite concentrations. The relative abundance of each metabolite was not strikingly different between genders and genotypes. Sulforaphane is metabolized and reaches target tissues in wild-type and Nrf2(-/-) mice. These data provide further evidence that sulforaphane is bioavailable and may be an effective dietary chemoprevention agent for several tissue sites.

  8. Nrf2 activation involves an oxidative-stress independent pathway in tetrafluoroethylcysteine-induced cytotoxicity.

    Science.gov (United States)

    Ho, Han K; White, Collin C; Fernandez, Carolina; Fausto, Nelson; Kavanagh, Terrance J; Nelson, Sidney D; Bruschi, Sam A

    2005-08-01

    Tetrafluoroethylcysteine (TFEC), a metabolite of the industrial gas tetrafluoroethylene, can cause both nephrotoxicity and limited hepatotoxicity in animal models, and this is associated with the covalent modification of specific intramitochondrial proteins including heat shock protein 60 (HSP60), mitochondrial HSP70 (mtHSP70), aspartate aminotransferase (AST), aconitase, and alpha-ketoglutarate dehydrogenase (alphaKGDH). Using the murine TAMH cell line as a useful in vitro model for TFEC toxicity, we demonstrate a rapid and sustained induction of Nrf2, a member of the "cap-and-collar" transcription factor family, following exposure to cytotoxic concentrations of TFEC. A functional correlate was also established with the rapid translocation of cytosolic Nrf2 into the nucleus. In addition, transcriptional and translational upregulation of known Nrf2 regulated genes including glutamate cysteine ligase (GCL), both catalytic and modulatory subunits, heme oxygenase-1, and glutathione S-transferase (GST) isoforms were detected. While Nrf2 activation is often linked to perturbation of cellular thiol status and/or oxidative stress, we were unable to detect any significant depletion of cellular glutathione or oxidation of mitochondrial membrane cardiolipin or increases in reactive oxygen species (ROS). These data suggest Nrf2 activation is likely independent of classical oxidative stress or, at best, a result of a transient, low-level redox stress. Moreover, supporting evidence indicates an early endoplasmic reticular (ER) stress response after TFEC treatment, with a time-dependent upregulation of the ER responsive genes gadd34, gadd45, gadd153, and ndr1 . These findings suggest an alternative pathway for Nrf2 activation, i.e., Nrf2 phosphorylation through ER-mediated protein kinases such as PKR-like endoplasmic reticular kinase (PERK). Overall, the results implicate a role for Nrf2 in the cellular response to TFEC toxicity and suggest a previously unrecognized role for the

  9. Sulforaphane prevents pulmonary damage in response to inhaled arsenic by activating the Nrf2-defense response

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yi [Department of Environmental and Occupational Health, School of Public Health, China Medical University, Shenyang, Liaoning 110001 (China); Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, AZ 85721 (United States); Tao, Shasha [Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, AZ 85721 (United States); Lian, Fangru [Department of Pathology, University of Arizona, 1501 North Campbell Ave, Tucson, AZ 85724 (United States); Chau, Binh T. [Department of Cellular and Molecular Medicine, The University of Arizona, 1501 North Campbell Ave, Tucson, AZ 85724 (United States); Chen, Jie; Sun, Guifan [Department of Environmental and Occupational Health, School of Public Health, China Medical University, Shenyang, Liaoning 110001 (China); Fang, Deyu [Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 (United States); Lantz, R. Clark [Department of Cellular and Molecular Medicine, The University of Arizona, 1501 North Campbell Ave, Tucson, AZ 85724 (United States); Arizona Cancer Center, University of Arizona, 1515 North Campbell Avenue, Tucson, AZ 85724 (United States); Zhang, Donna D., E-mail: dzhang@pharmacy.arizona.edu [Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, AZ 85721 (United States); Arizona Cancer Center, University of Arizona, 1515 North Campbell Avenue, Tucson, AZ 85724 (United States)

    2012-12-15

    Exposure to arsenic is associated with an increased risk of lung disease. Novel strategies are needed to reduce the adverse health effects associated with arsenic exposure in the lung. Nrf2, a transcription factor that mediates an adaptive cellular defense response, is effective in detoxifying environmental insults and prevents a broad spectrum of diseases induced by environmental exposure to harmful substances. In this report, we tested whether Nrf2 activation protects mice from arsenic-induced toxicity. We used an in vivo arsenic inhalation model that is highly relevant to low environmental human exposure to arsenic-containing dusts. Two-week exposure to arsenic-containing dust resulted in pathological alterations, oxidative DNA damage, and mild apoptotic cell death in the lung; all of which were blocked by sulforaphane (SF) in an Nrf2-dependent manner. Mechanistically, SF-mediated activation of Nrf2 alleviated inflammatory responses by modulating cytokine production. This study provides strong evidence that dietary intervention targeting Nrf2 activation is a feasible approach to reduce adverse health effects associated with arsenic exposure. -- Highlights: ► Exposed to arsenic particles and/or SF have elevated Nrf2 and its target genes. ► Sulforaphane prevents pathological alterations, oxidative damage and cell death. ► Sulforaphane alleviates infiltration of inflammatory cells into the lungs. ► Sulforaphane suppresses arsenic-induced proinflammatory cytokine production.

  10. Nrf2 mitigates LRRK2- and α-synuclein-induced neurodegeneration by modulating proteostasis.

    Science.gov (United States)

    Skibinski, Gaia; Hwang, Vicky; Ando, Dale Michael; Daub, Aaron; Lee, Alicia K; Ravisankar, Abinaya; Modan, Sara; Finucane, Mariel M; Shaby, Benjamin A; Finkbeiner, Steven

    2017-01-31

    Mutations in leucine-rich repeat kinase 2 (LRRK2) and α-synuclein lead to Parkinson's disease (PD). Disruption of protein homeostasis is an emerging theme in PD pathogenesis, making mechanisms to reduce the accumulation of misfolded proteins an attractive therapeutic strategy. We determined if activating nuclear factor erythroid 2-related factor (Nrf2), a potential therapeutic target for neurodegeneration, could reduce PD-associated neuron toxicity by modulating the protein homeostasis network. Using a longitudinal imaging platform, we visualized the metabolism and location of mutant LRRK2 and α-synuclein in living neurons at the single-cell level. Nrf2 reduced PD-associated protein toxicity by a cell-autonomous mechanism that was time-dependent. Furthermore, Nrf2 activated distinct mechanisms to handle different misfolded proteins. Nrf2 decreased steady-state levels of α-synuclein in part by increasing α-synuclein degradation. In contrast, Nrf2 sequestered misfolded diffuse LRRK2 into more insoluble and homogeneous inclusion bodies. By identifying the stress response strategies activated by Nrf2, we also highlight endogenous coping responses that might be therapeutically bolstered to treat PD.

  11. ROLE OF NRF2 IN THE OXIDATIVE STRESS-DEPENDENT HYPERTENSION ASSOCIATED WITH THE DEPLETION OF DJ-1

    Science.gov (United States)

    Cuevas, Santiago; Yang, Yu; Konkalmatt, Prasad; Asico, Laureano; Feranil, Jun; Jones, John; Villar, Van Anthony; Armando, Ines; Jose, Pedro A.

    2015-01-01

    Renal dopamine 2 receptor dysfunction is associated with oxidative stress and high blood pressure. We have reported that DJ-1, an oxidative stress response protein, is positively regulated by dopamine 2 receptor in the kidney. The transcription factor Nrf2 regulates the expression of several antioxidant genes. We tested the hypothesis that Nrf2 is involved in the renal DJ-1-mediated inhibition of reactive oxygen species production. We have reported that silencing dopamine 2 receptor in mouse renal proximal tubule cells decreases the expression of DJ-1. We now report that silencing DJ-1 or dopamine 2 receptor in mouse proximal tubule cells and mouse kidneys, decreases Nrf2 expression and activity and increases reactive oxygen species production; blood pressure is also increased in mice in which renal DJ-1 or dopamine 2 receptor is silenced. DJ-1−/− mice have decreased renal Nrf2 expression and activity, and increased nitro-tyrosine levels an dopamine 2 receptor d blood pressure. Silencing Nrf2 in mouse proximal tubule cells does not alter the expression of DJ-1 or dopamine 2 receptor, indicating that Nrf2 is downstream of dopamine 2 receptor and DJ-1. A Nrf2 inducer, bardoxolone, normalizes the systolic blood pressure and renal malondialdehyde levels in DJ-1−/− mice without affecting them in their wild-type littermates. Because Nrf2 ubiquitination is increased in DJ-1−/− mice, we conclude that the protective effect of DJ-1 on renal oxidative stress is mediated, in part, by preventing Nrf2 degradation. Moreover, renal dopamine 2 receptor and DJ-1 are necessary for normal Nrf2 activity to keep a normal redox balance and blood pressure. PMID:25895590

  12. miRNA-141 attenuates UV-induced oxidative stress via activating Keap1-Nrf2 signaling in human retinal pigment epithelium cells and retinal ganglion cells

    Science.gov (United States)

    Cheng, Li-Bo; Li, Ke-ran; Yi, Nan; Li, Xiu-miao; Wang, Feng; Xue, Bo; Pan, Ying-shun; Yao, Jin; Jiang, Qin; Wu, Zhi-feng

    2017-01-01

    Activation of NF-E2-related factor 2 (Nrf2) signaling could protect cells from ultra violet (UV) radiation. We aim to provoke Nrf2 activation via downregulating its inhibitor Keap1 by microRNA-141 (“miR-141”). In both human retinal pigment epithelium cells (RPEs) and retinal ganglion cells (RGCs), forced-expression of miR-141 downregulated Keap1, causing Nrf2 stabilization, accumulation and nuclear translocation, which led to transcription of multiple antioxidant-responsive element (ARE) genes (HO1, NOQ1 and GCLC). Further, UV-induced reactive oxygen species (ROS) production and cell death were significantly attenuated in miR-141-expressing RPEs and RGCs. On the other hand, depletion of miR-141 via expressing its inhibitor antagomiR-141 led to Keap1 upregulation and Nrf2 degradation, which aggravated UV-induced death of RPEs and RGCs. Significantly, Nrf2 shRNA knockdown almost abolished miR-141-mediated cytoprotection against UV in RPEs. These results demonstrate that miR-141 targets Keap1 to activate Nrf2 signaling, which protects RPEs and RGCs from UV radiation. PMID:28061435

  13. Panaxatriol Saponins Attenuated Oxygen-Glucose Deprivation Injury in PC12 Cells via Activation of PI3K/Akt and Nrf2 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Yongliang Huang

    2014-01-01

    Full Text Available Panaxatriol saponins (PTS, the main components extracted from Panax notoginseng, have been shown to be efficacious in the prevention and treatment of cerebrovascular diseases in China. NF-E2-related factor 2 (Nrf2, a transcription factor regulating antioxidant and cytoprotective responses to oxidative stress, has received particular attention as a molecular target for pharmacological intervention of ischemic diseases. The aim of this study was to characterize the effect of PTS on the activation of Nrf2 signaling pathway and the potential role in its protective effect. We found that PTS induced heme oxygenase-1 (HO-1 expression in PC12 cells via activating Nrf2 signaling pathway. Phosphatidylinositol 3-kinase (PI3K/Akt kinase was involved in the upstream of this PTS activated pathway. Moreover, combination of the main components in PTS significantly enhanced the expression of Nrf2 mediated phase II enzymes. Importantly, the protective effect of PTS against oxygen-glucose deprivation-reperfusion (OGD-Rep induced cell death was significantly attenuated by PI3K inhibitor and antioxidant response element (ARE decoy oligonucleotides, suggesting that both PI3K/Akt and Nrf2 signaling pathway are essential during this protective process. Taken together, our results suggest that PTS may activate endogenous cytoprotective mechanism against OGD-Rep induced oxidative injury via the activation of PI3K/Akt and Nrf2 signaling pathway.

  14. Activation of the NRF2-ARE signalling pathway by the Lentinula edodes polysaccharose LNT alleviates ROS-mediated cisplatin nephrotoxicity.

    Science.gov (United States)

    Chen, Qian; Peng, Huixia; Dong, Lei; Chen, Lijuan; Ma, Xiaobin; Peng, Yuping; Dai, Shejiao; Liu, Qiang

    2016-07-01

    The nephrotoxicity of cisplatin (cis-DDP) limits its general clinical applications. Lentinan (LNT), a dextran extracted from the mushroom Lentinula edodes, has been shown to have multiple pharmacological activities. The primary objective of the current study was to determine whether and how LNT alleviates cis-DDP- induced cytotoxicity in HK-2 cells and nephrotoxicity in mice. LNT did not interfere with cisplatin's anti-tumour efficacy in vitro and functioned cooperatively with cis-DDP to inhibit activity in HeLa and A549 tumour cells. LNT alleviated the cis-DDP-induced decrease in HK-2 cell viability, caspase-3 activation and cleavage of the DNA repair enzyme PARP, decreased HK-2 cell apoptosis and inhibited reactive oxygen species (ROS) accumulation in HK-2 cells. The inhibitor of ROS (N-acetyl-L-cysteine, NAC) could decreased the apoptosis of HK-2 cell. In addition, LNT significantly prevented cis-DDP-induced kidney injury in vivo. LNT itself could not eliminate ROS levels in vitro. Further studies demonstrated that LNT induced NF-E2 p45-related factor 2 (Nrf2) protein and mRNA expression in a time- and dose-dependent manner. LNT promoted Nrf2 translocation to the nucleus and binding to the antioxidant-response element (ARE) sequence and induced the transcription and translation of heme oxygenase 1 (HO-1), aldo-keto reductases 1C1 and 1C2 (AKR1C), and NADP(H):quinone oxidoreductase 1 (NQO1). Finally, we used hNrf2 siRNA and an Nrf2 agonist (tBHQ) to inhibit or enhance Nrf2 expression. The results demonstrated that the LNT-mediated alleviation of cis-DDP-induced nephrotoxicity was achieved by preventing the accumulation of ROS in a manner that depended on the activation of the Nrf2-ARE signalling pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Isolating a cytoprotective compound from Ganoderma tsugae: effects on induction of Nrf-2-related genes in endothelial cells.

    Science.gov (United States)

    Wei, Yu-Shan; Wung, Being-Sun; Lin, Yuan-Chun; Hsieh, Chia-Wen

    2009-08-01

    Ganoderma tsugae is a medicinal fungus with several biological activities. It has long been used as a folk remedy for the promotion of health and longevity in China and other oriental countries. Here, a bioactive fraction of G. tsugae was progressively purified to be enriched in the activity of cytoprotective enzymes. The highest bioactivity was detected in the 20% EtOH-precipitated fraction, which was prepared from submerged fermentation filtrate of G. tsugae. Following further purification by gel filtration chromatography and acetone extraction, the most bioactive fraction, F5-2, was identified as a peptidoglycan-like compound. Extracts of G. tsugae (F5-2) induced heme oxygenase-1 (HO-1) and thioredoxin reductase-1 (TrxR1) expression in endothelial cells by increasing NF-E2-related factor-2 (Nrf2) nuclear translocation. Pretreatment with F5-2 increased intracellular glutathione (GSH) and protected against H(2)O(2), suggesting that induction of these antioxidant enzymes is important in protection against oxidative stress. Hence the bioactive peptidoglycan-like compound from G. tsugae might protect endothelial cells.

  16. Attenuation of Aβ{sub 25–35}-induced parallel autophagic and apoptotic cell death by gypenoside XVII through the estrogen receptor-dependent activation of Nrf2/ARE pathways

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Xiangbao; Wang, Min [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193 (China); Sun, Guibo, E-mail: sunguibo@126.com [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193 (China); Ye, Jingxue [Jilin Agricultural University, Changchun, Jilin 130021 (China); Zhou, Yanhui [Center of Cardiology, People' s Hospital of Jilin Province, Changchun, 130021, Jilin (China); Dong, Xi [Wenzhou Medical University, Wenzhou, Zhejiang 325035 (China); Wang, Tingting; Lu, Shan [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193 (China); Sun, Xiaobo, E-mail: sun_xiaobo163@163.com [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193 (China)

    2014-08-15

    Amyloid-beta (Aβ) has a pivotal function in the pathogenesis of Alzheimer's disease. To investigate Aβ neurotoxicity, we used an in vitro model that involves Aβ{sub 25–35}-induced cell death in the nerve growth factor-induced differentiation of PC12 cells. Aβ{sub 25–35} (20 μM) treatment for 24 h caused apoptotic cell death, as evidenced by significant cell viability reduction, LDH release, phosphatidylserine externalization, mitochondrial membrane potential disruption, cytochrome c release, caspase-3 activation, PARP cleavage, and DNA fragmentation in PC12 cells. Aβ{sub 25–35} treatment led to autophagic cell death, as evidenced by augmented GFP-LC3 puncta, conversion of LC3-I to LC3-II, and increased LC3-II/LC3-I ratio. Aβ{sub 25–35} treatment induced oxidative stress, as evidenced by intracellular ROS accumulation and increased production of mitochondrial superoxide, malondialdehyde, protein carbonyl, and 8-OHdG. Phytoestrogens have been proved to be protective against Aβ-induced neurotoxicity and regarded as relatively safe targets for AD drug development. Gypenoside XVII (GP-17) is a novel phytoestrogen isolated from Gynostemma pentaphyllum or Panax notoginseng. Pretreatment with GP-17 (10 μM) for 12 h increased estrogen response element reporter activity, activated PI3K/Akt pathways, inhibited GSK-3β, induced Nrf2 nuclear translocation, augmented antioxidant responsive element enhancer activity, upregulated heme oxygenase 1 (HO-1) expression and activity, and provided protective effects against Aβ{sub 25–35}-induced neurotoxicity, including oxidative stress, apoptosis, and autophagic cell death. In conclusion, GP-17 conferred protection against Aβ{sub 25–35}-induced neurotoxicity through estrogen receptor-dependent activation of PI3K/Akt pathways, inactivation of GSK-3β and activation of Nrf2/ARE/HO-1 pathways. This finding might provide novel insights into understanding the mechanism for neuroprotective effects of phytoestrogens

  17. NRF2 ACTIVATION AS TARGET TO IMPLEMENT THERAPEUTIC TREATMENTS

    Directory of Open Access Journals (Sweden)

    Velio eBocci

    2015-02-01

    Full Text Available A chronic increase of oxidative stress is typical of serious pathologies such as myocardial infarction, stroke, chronic limb ischemia, chronic obstructive pulmonary disease (COPD, type II-diabetes, age-related macular degeneration leads to an epic increase of morbidity and mortality in all countries of the world. The initial inflammation followed by an excessive release of reactive oxygen species (ROS implies a diffused cellular injury that needs to be corrected by an inducible expression of the innate detoxifying and antioxidant system. The transcription factor Nrf2, when properly activated, is able to restore a redox homeostasis and possibly improve human health.

  18. NRF2 Activation as Target to Implement Therapeutic Treatments

    Science.gov (United States)

    Bocci, Velio; Valacchi, Giuseppe

    2015-02-01

    A chronic increase of oxidative stress is typical of serious pathologies such as myocardial infarction, stroke, chronic limb ischemia, chronic obstructive pulmonary disease (COPD), type II-diabetes, age-related macular degeneration leads to an epic increase of morbidity and mortality in all countries of the world. The initial inflammation followed by an excessive release of reactive oxygen species (ROS) implies a diffused cellular injury that needs to be corrected by an inducible expression of the innate detoxifying and antioxidant system. The transcription factor Nrf2, when properly activated, is able to restore a redox homeostasis and possibly improve human health.

  19. Disruption of Nrf2/ARE signaling impairs antioxidant mechanisms and promotes cell degradation pathways in aged skeletal muscle.

    Science.gov (United States)

    Miller, Corey J; Gounder, Sellamuthu S; Kannan, Sankaranarayanan; Goutam, Karan; Muthusamy, Vasanthi R; Firpo, Matthew A; Symons, J David; Paine, Robert; Hoidal, John R; Rajasekaran, Namakkal Soorappan

    2012-06-01

    Age-associated decline in antioxidant potential and accumulation of reactive oxygen/nitrogen species are primary causes for multiple health problems, including muscular dystrophy and sarcopenia. The role of the nuclear erythroid-2-p45-related factor-2 (Nrf2) signaling has been implicated in antioxidant gene regulation. Here, we investigated the loss-of-function mechanisms for age-dependent regulation of Nrf2/ARE (Antioxidant Response Element) signaling in skeletal muscle (SM). Under basal physiological conditions, disruption of Nrf2 showed minimal effects on antioxidant defenses in young (2months) Nrf2-/- mice. Interestingly, mRNA and protein levels of NADH Quinone Oxidase-1 were dramatically (*P24months) had a significant increase in ROS along with a decrease in glutathione (GSH) levels and impaired antioxidants in Nrf2-/- when compared to WT SM. Further, disruption of Nrf2 appears to induce oxidative stress (increased ROS, HNE-positive proteins), ubiquitination and pro-apoptotic signals in the aged SM of Nrf2-/- mice. These results indicate a direct role for Nrf2/ARE signaling on impairment of antioxidants, which contribute to muscle degradation pathways upon aging. Our findings conclude that though the loss of Nrf2 is not amenable at younger age; it could severely affect the SM defenses upon aging. Thus, Nrf2 signaling might be a potential therapeutic target to protect the SM from age-dependent accumulation of ROS by rescuing redox homeostasis to prevent age-related muscle disorders such as sarcopenia and myopathy. © 2012 Elsevier B.V. All rights reserved.

  20. Sulforaphane Suppresses Hepatitis C Virus Replication by Up-Regulating Heme Oxygenase-1 Expression through PI3K/Nrf2 Pathway.

    Directory of Open Access Journals (Sweden)

    Jung-Sheng Yu

    Full Text Available Hepatitis C virus (HCV infection-induced oxidative stress is a major risk factor for the development of HCV-associated liver disease. Sulforaphane (SFN is an antioxidant phytocompound that acts against cellular oxidative stress and tumorigenesis. However, there is little known about its anti-viral activity. In this study, we demonstrated that SFN significantly suppressed HCV protein and RNA levels in HCV replicon cells and infectious system, with an IC50 value of 5.7 ± 0.2 μM. Moreover, combination of SFN with anti-viral drugs displayed synergistic effects in the suppression of HCV replication. In addition, we found nuclear factor erythroid 2-related factor 2 (Nrf2/HO-1 induction in response to SFN and determined the signaling pathways involved in this process, including inhibition of NS3 protease activity and induction of IFN response. In contrast, the anti-viral activities were attenuated by knockdown of HO-1 with specific inhibitor (SnPP and shRNA, suggesting that anti-HCV activity of SFN is dependent on HO-1 expression. Otherwise, SFN stimulated the phosphorylation of phosphoinositide 3-kinase (PI3K leading Nrf2-mediated HO-1 expression against HCV replication. Overall, our results indicated that HO-1 is essential in SFN-mediated anti-HCV activity and provide new insights in the molecular mechanism of SFN in HCV replication.

  1. Myricitrin Attenuates High Glucose-Induced Apoptosis through Activating Akt-Nrf2 Signaling in H9c2 Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Bin Zhang

    2016-07-01

    Full Text Available Hyperglycemia, as well as diabetes mellitus, has been shown to trigger cardiac cell apoptosis. We have previously demonstrated that myricitrin prevents endothelial cell apoptosis. However, whether myricitrin can attenuate H9c2 cell apoptosis remains unknown. In this study, we established an experiment model in H9c2 cells exposed to high glucose. We tested the hypothesis that myricitrin may inhibit high glucose (HG-induced cardiac cell apoptosis as determined by TUNEL staining. Furthermore, myricitrin promoted antioxidative enzyme production, suppressed high glucose-induced reactive oxygen species (ROS production and decreased mitochondrial membrane potential (MMP in H9c2 cells. This agent significantly inhibited apoptotic protein expression, activated Akt and facilitated the transcription of NF-E2-related factor 2 (Nrf2-mediated protein (heme oxygenase-1 (HO-1 and quinone oxidoreductase 1 (NQO-1 expression as determined by Western blotting. Significantly, an Akt inhibitor (LY294002 or HO-1 inhibitor (ZnPP not only inhibited myricitrin-induced HO-1/NQO-1 upregulation but also alleviated its anti-apoptotic effects. In summary, these observations demonstrate that myricitrin activates Nrf2-mediated anti-oxidant signaling and attenuates H9c2 cell apoptosis induced by high glucose via activation of Akt signaling.

  2. A novel antioxidant peptide, purified from Bacillus amyloliquefaciens, showed strong antioxidant potential via Nrf-2 mediated heme oxygenase-1 expression.

    Science.gov (United States)

    Rahman, Md Saifur; Hee Choi, Yun; Seok Choi, Yoon; Alam, Md Badrul; Han Lee, Sang; Cheol Yoo, Jin

    2018-01-15

    A novel antioxidant peptide YD1 (∼1.0kDa), purified from the strain Bacillus amyloliquefaciens CBSYD1, displayed activity in several in vitro assays and was also efficient against Gram-positive, Gram-negative as well as multidrug-resistant (MDR) bacteria. Strain growth was adapted to bile-salt conditions where a clear halos-zone was observed in a bile-salt plate assay and was viable in different digestive track conditions. YD1 treatment on RAW 264.7 cells increased the transcriptional and translational activities of NF-E2-related factor-2 (Nrf-2) through the enhanced levels of heme oxygenase-1 (HO-1). Furthermore, the YD1-treated group showed higher levels of antioxidant enzymes compared to the oxidative stress group. YD1 demonstrated a strong antioxidant activity by decreasing nitric oxide (NO) and reactive oxygen species (ROS) in RAW 264.7 cells. This study suggests that YD1 and the strain could be a natural antioxidant and a probiotic candidate respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. EGFR mediates astragaloside IV-induced Nrf2 activation to protect cortical neurons against in vitro ischemia/reperfusion damages

    International Nuclear Information System (INIS)

    Gu, Da-min; Lu, Pei-Hua; Zhang, Ke; Wang, Xiang; Sun, Min; Chen, Guo-Qian; Wang, Qiong

    2015-01-01

    In this study, we tested the potential role of astragaloside IV (AS-IV) against oxygen and glucose deprivation/re-oxygenation (OGD/R)-induced damages in murine cortical neurons, and studied the associated signaling mechanisms. AS-IV exerted significant neuroprotective effects against OGD/R by reducing reactive oxygen species (ROS) accumulation, thereby attenuating oxidative stress and neuronal cell death. We found that AS-IV treatment in cortical neurons resulted in NF-E2-related factor 2 (Nrf2) signaling activation, evidenced by Nrf2 Ser-40 phosphorylation, and its nuclear localization, as well as transcription of antioxidant-responsive element (ARE)-regulated genes: heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO-1) and sulphiredoxin 1 (SRXN-1). Knockdown of Nrf2 through lentiviral shRNAs prevented AS-IV-induced ARE genes transcription, and abolished its anti-oxidant and neuroprotective activities. Further, we discovered that AS-IV stimulated heparin-binding-epidermal growth factor (HB-EGF) release to trans-activate epidermal growth factor receptor (EGFR) in cortical neurons. Blockage or silencing EGFR prevented Nrf2 activation by AS-IV, thus inhibiting AS-IV-mediated anti-oxidant and neuroprotective activities against OGD/R. In summary, AS-IV protects cortical neurons against OGD/R damages through activating of EGFR-Nrf2 signaling. - Highlights: • Pre-treatment of astragaloside IV (AS-IV) protects murine cortical neurons from OGD/R. • AS-IV activates Nrf2-ARE signaling in murine cortical neurons. • Nrf2 is required for AS-IV-mediated anti-oxidant and neuroprotective activities. • AS-IV stimulates HB-EGF release to trans-activate EGFR in murine cortical neurons. • EGFR mediates AS-IV-induced Nrf2 activation and neuroprotection against OGD/R

  4. EGFR mediates astragaloside IV-induced Nrf2 activation to protect cortical neurons against in vitro ischemia/reperfusion damages

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Da-min [Department of Anesthesiology, Affiliated Yixing People' s Hospital, Jiangsu University, Yixing (China); Lu, Pei-Hua, E-mail: lphty1_1@163.com [Department of Medical Oncology, Wuxi People' s Hospital Affiliated to Nanjing Medical University, Wuxi (China); Zhang, Ke; Wang, Xiang [Department of Anesthesiology, Affiliated Yixing People' s Hospital, Jiangsu University, Yixing (China); Sun, Min [Department of General Surgery, Affiliated Yixing People' s Hospital, Jiangsu University, Yixing (China); Chen, Guo-Qian [Department of Clinical Laboratory, Wuxi People' s Hospital Affiliated to Nanjing Medical University, Wuxi (China); Wang, Qiong, E-mail: WangQiongprof1@126.com [Department of Clinical Laboratory, Wuxi People' s Hospital Affiliated to Nanjing Medical University, Wuxi (China)

    2015-02-13

    In this study, we tested the potential role of astragaloside IV (AS-IV) against oxygen and glucose deprivation/re-oxygenation (OGD/R)-induced damages in murine cortical neurons, and studied the associated signaling mechanisms. AS-IV exerted significant neuroprotective effects against OGD/R by reducing reactive oxygen species (ROS) accumulation, thereby attenuating oxidative stress and neuronal cell death. We found that AS-IV treatment in cortical neurons resulted in NF-E2-related factor 2 (Nrf2) signaling activation, evidenced by Nrf2 Ser-40 phosphorylation, and its nuclear localization, as well as transcription of antioxidant-responsive element (ARE)-regulated genes: heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO-1) and sulphiredoxin 1 (SRXN-1). Knockdown of Nrf2 through lentiviral shRNAs prevented AS-IV-induced ARE genes transcription, and abolished its anti-oxidant and neuroprotective activities. Further, we discovered that AS-IV stimulated heparin-binding-epidermal growth factor (HB-EGF) release to trans-activate epidermal growth factor receptor (EGFR) in cortical neurons. Blockage or silencing EGFR prevented Nrf2 activation by AS-IV, thus inhibiting AS-IV-mediated anti-oxidant and neuroprotective activities against OGD/R. In summary, AS-IV protects cortical neurons against OGD/R damages through activating of EGFR-Nrf2 signaling. - Highlights: • Pre-treatment of astragaloside IV (AS-IV) protects murine cortical neurons from OGD/R. • AS-IV activates Nrf2-ARE signaling in murine cortical neurons. • Nrf2 is required for AS-IV-mediated anti-oxidant and neuroprotective activities. • AS-IV stimulates HB-EGF release to trans-activate EGFR in murine cortical neurons. • EGFR mediates AS-IV-induced Nrf2 activation and neuroprotection against OGD/R.

  5. Concerted action of p62 and Nrf2 protects cells from palmitic acid-induced lipotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Su [Severance Biomedical Science Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kang, Dong Hoon [Department of Life Science and Ewha Research Center for Systems Biology (Korea, Republic of); The Research Center for Cell Homeostasis, Ewha Womans University, Seoul 127-750 (Korea, Republic of); Lee, Da Hyun [Severance Biomedical Science Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Bae, Soo Han, E-mail: soohanbae@yuhs.ac [Severance Biomedical Science Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of)

    2015-10-09

    Nonalcoholic fatty liver disease (NAFLD), frequently associated with obesity and diabetes mellitus, is caused by the accumulation of excess fatty acids within liver cells. Palmitic acid (PA), a common saturated fatty acid found in mammals, induces the generation of reactive oxygen species (ROS) and elicits apoptotic cell death, known as lipotoxicity. However, protective mechanisms against PA-induced lipotoxicity have not been elucidated. In this study, we aimed to clarify the role of p62, an adapter protein in the autophagic process, as well as the nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway, in protecting cells from PA-induced lipotoxicity. The Nrf2-Keap1 pathway is essential for the protection of cells from oxidative stress. p62 enhances its binding to Keap1 and leads to Nrf2 activation. Here, we show that PA potentiates Keap1 degradation and thereby activates the transcription of Nrf2 target genes partially through autophagy. Furthermore, this PA-mediated Keap1 degradation depends on p62. Correspondingly, a lack of p62 attenuates the PA-mediated Nrf2 activation and increases the susceptibility of cells to oxidative stress. These results indicate that p62 plays an important role in protecting cells against lipotoxicity through Keap1 degradation-mediated Nrf2 activation. - Highlights: • PA induces Keap1 downregulation and activates Nrf2 target gene transcription. • PA-induced Keap1 degradation is partly mediated by the autophagic pathway. • PA-induced Keap1 degradation depends on p62. • Ablation of p62 exacerbates PA-mediated apoptotic cell death.

  6. Pirfenidone attenuates bleomycin-induced pulmonary fibrosis in mice by regulating Nrf2/Bach1 equilibrium.

    Science.gov (United States)

    Liu, Yuan; Lu, Fuai; Kang, Lirong; Wang, Zhihua; Wang, Yongfu

    2017-04-18

    Oxidative stress is one of the important factors involved in the pathogenesis of idiopathic pulmonary fibrosis (IPF). The equilibrium of Nuclear factor-erythroid-related factor 2 (Nrf2)/[BTB (broad-complex, tramtrack and bric-a-brac) and CNC (cap'n'collar protein) homology 1, Bach1] determines the expression level of antioxidant factors, further regulating the function of oxidation/antioxidation capacity. Pirfenidone (PFD) is one of two currently for IPF therapy approved drugs. PFD regulates intracellular antioxidants, inhibits secretion of inflammatory cytokines and collagen synthesis. However the mechanisms of its antioxidant effects remain elusive. Effects of PFD treatment were studied in mouse lung fibroblasts (MLF) following induction by transforming-growth factor beta 1 (TGF-β1) and in mice following bleomycin-induced lung fibrosis. The mRNA and protein levels of oxidative stress-related factors Nrf2/Bach1 and their downstream antioxidant factors heme oxygenase-1 (Ho-1) and glutathione peroxidase 1 (Gpx1) were determined by RT-PCR and Western blot. Fibrosis-related cytokines interleukin-6 (IL-6) and myofibroblast markers type 1 collagen α1 (COL1A1) levels in supernate of MLF, serum, and bronchoalveolar lavage fluid (BALF) as well as malondialdehyde (MDA) in serum and BALF were detected by ELISA, reactive oxygen species (ROS) generation was measured by 2',7'- dichlorofluorescin diacetate (DCFH-DA) assay and lung pathological/morphological alterations in mice were observed by HE and Masson to assess the antioxidant mechanism and therapeutic effects on pulmonary fibrosis induced by bleomycin. PFD inhibited Bach1 mRNA and protein expressions in mouse lung fibroblasts induced by TGF-β1 and lung tissues with pulmonary fibrosis induced by bleomycin. Furthermore, it improved Nrf2, Ho-1 and Gpx1 mRNA and protein expressions. After PFD treatment, COL1A1and IL-6 levels in supernate of MLF, serum, and BALF as well as ROS in lung tissues and MDA in serum and BALF from

  7. Alteration of Nrf2 and Glutamate Cysteine Ligase expression contribute to lesions growth and fibrogenesis in ectopic endometriosis.

    Science.gov (United States)

    Marcellin, L; Santulli, P; Chouzenoux, S; Cerles, O; Nicco, C; Dousset, B; Pallardy, M; Kerdine-Römer, S; Just, P A; Chapron, C; Batteux, F

    2017-09-01

    The redox-sensitive nuclear factor erythroid-derived 2-like 2 (NRF2) controls endogenous antioxidant enzymes' transcription and protects against oxidative damage which is triggered by inflammation and known to favor progression of endometriosis. Glutamate Cysteine Ligase (GCL), a target gene of NRF2, is the first enzyme in the synthesis cascade of glutathione, an important endogenous antioxidant. Sixty-one patients, with thorough surgical examination of the abdominopelvic cavity, were recruited for the study: 31 with histologically-proven endometriosis and 30 disease-free women taken as controls. Expressions of NRF2 and GCL were investigated by quantitative RT-PCR and immunohistochemistry in eutopic and ectopic endometria from endometriosis-affected women and in endometrium of disease-free women. Ex vivo stromal and epithelial cells were extracted and purified from endometrial and endometriotic biopsies to explore expression of NRF2 and GCL in both stromal and epithelial compartments by western blot. Finally, in order to strengthen the role of NRF2 in endometriosis pathogenesis, we evaluated the drop of NRF2 expression in a mouse model of endometriosis using NRF2 knockout (NRF2 -/- ) mice. The mRNA levels of NRF2 and GCL were significantly lower in ectopic endometria of endometriosis-affected women compared to eutopic endometria of disease-free women. The immunohistochemical analysis confirmed the decreased expression of both NRF2 and GCL in ectopic endometriotic tissues compared to eutopic endometria of endometriosis-affected and disease-free women. Immunoblotting revealed a significant decreased of NRF2 and GCL expression in epithelial and stroma cells from ectopic lesions of endometriosis-affected women compared to eutopic endometria from controls. Using a murine model of endometriosis, NRF2 -/- implants were more fibrotic compared to wild-type with an increased weight and volume. These findings indicate that expression of the transcription factor NRF2 and its

  8. Effects of Nrf2 deficiency on arsenic metabolism in mice.

    Science.gov (United States)

    Wang, Huihui; Zhu, Jiayu; Li, Lu; Li, Yongfang; Lv, Hang; Xu, Yuanyuan; Sun, Guifan; Pi, Jingbo

    2017-12-15

    Inorganic arsenic (iAs) is a known toxicant and carcinogen. Worldwide arsenic exposure has become a threat to human health. The severity of arsenic toxicity is strongly correlated with the speed of arsenic metabolism (methylation) and clearance. Furthermore, oxidative stress is recognized as a major mechanism for arsenic-induced toxicity. Nuclear factor-E2-related factor 2 (Nrf2), a key regulator in cellular adaptive antioxidant response, is clearly involved in alleviation of arsenic-induced oxidative damage. Multiple studies demonstrate that Nrf2 deficiency mice are more vulnerable to arsenic-induced intoxication. However, what effect Nrf2 deficiency might have on arsenic metabolism in mice is still unknown. In the present study, we measured the key enzymes involved in arsenic metabolism in Nrf2-WT and Nrf2-KO mice. Our results showed that basal transcript levels of glutathione S-transferase omega 2 (Gsto2) were significantly higher and GST mu 1 (Gstm1) lower in Nrf2-KO mice compared to Nrf2-WT control. Arsenic speciation and methylation rate in liver and urine was then studied in mice treated with 5mg/kg sodium arsenite for 12h. Although there were some alterations in arsenic metabolism enzymes between Nrf2-WT and Nrf2-KO mice, the Nrf2 deficiency had no significant effect on arsenic methylation. These results suggest that the Nrf2-KO mice are more sensitive to arsenic than Nrf2-WT mainly because of differences in adaptive antioxidant detoxification capacity rather than arsenic methylation capacity. Copyright © 2017. Published by Elsevier Inc.

  9. Aging-related decline in the induction of Nrf2-regulated antioxidant genes in human bronchial epithelial cells

    Directory of Open Access Journals (Sweden)

    Lulu Zhou

    2018-04-01

    Full Text Available Evidence from animal studies suggests that stress-induced increases in Nrf2-regulated antioxidant gene expression, a critical mechanism of cellular protection, declines with aging. This study examined whether this also occurs in humans. We measured the basal and inducible levels of Nrf2-regulated antioxidant genes in human bronchial epithelial (HBE cells from subjects of young adult (21–29 years and older (60–69 years non-smokers, and explored factors affecting expresion. The basal expression of three representative Nrf2-regulated genes, the catalytic and modulator subunits of glutamate cysteine ligase (GCLC and GCLM, respectively, and NAD(PH quinone oxidoreductase 1 (NQO1, was higher in cells from the older donors compared with cells from the young adult donors. Upon exposure to the Nrf2 activator, sulforaphane (SF, the expression of these antioxidant genes was increased in cells from both the young adults and the older donors; however, the induction by SF in older donor cells was significantly less than that seen in young adult cells. In addition, the activation of an EpRE-driven reporter by SF was lower in cells from older donors compared to cells from young adults. The basal expression of Nrf2 protein was also lower in cells from older donors than cells from young adults. Furthermore, we found that the basal expression of both Bach1 and c-Myc, two Nrf2 suppressors, was higher in cells from older adults than from young adult donors. In summary, our data suggest that, as in other species, basal expression of Nrf2-regulated genes increases with aging, while inducibility declines with aging. The increased expression of Nrf2 suppressors such as Bach1 and c-Myc may contribute to the impaired inducibility of the Nrf2-regulated antioxidant genes with aging in human bronchial epithelial cells.

  10. Translational control of Nrf2 within the open reading frame

    International Nuclear Information System (INIS)

    Perez-Leal, Oscar; Barrero, Carlos A.; Merali, Salim

    2013-01-01

    Highlights: •Identification of a novel Nrf2 translational repression mechanism. •The repressor is within the 3′ portion of the Nrf2 ORF. •The translation of Nrf2 or eGFP is reduced by the regulatory element. •The translational repression can be reversed with synonymous codon substitutions. •The molecular mechanism requires the mRNA sequence, but not the encoded amino acids. -- Abstract: Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) is a transcription factor that is essential for the regulation of an effective antioxidant and detoxifying response. The regulation of its activity can occur at transcription, translation and post-translational levels. Evidence suggests that under environmental stress conditions, new synthesis of Nrf2 is required – a process that is regulated by translational control and is not fully understood. Here we described the identification of a novel molecular process that under basal conditions strongly represses the translation of Nrf2 within the open reading frame (ORF). This mechanism is dependent on the mRNA sequence within the 3′ portion of the ORF of Nrf2 but not in the encoded amino acid sequence. The Nrf2 translational repression can be reversed with the use of synonymous codon substitutions. This discovery suggests an additional layer of control to explain the reason for the low Nrf2 concentration under quiescent state

  11. Compensatory role of the Nrf2–ARE pathway against paraquat toxicity: Relevance of 26S proteasome activity

    Directory of Open Access Journals (Sweden)

    Yasuhiko Izumi

    2015-11-01

    Full Text Available Oxidative stress and the ubiquitin–proteasome system play a key role in the pathogenesis of Parkinson disease. Although the herbicide paraquat is an environmental factor that is involved in the etiology of Parkinson disease, the role of 26S proteasome in paraquat toxicity remains to be determined. Using PC12 cells overexpressing a fluorescent protein fused to the proteasome degradation signal, we report here that paraquat yielded an inhibitory effect on 26S proteasome activity without an obvious decline in 20S proteasome activity. Relative low concentrations of proteasome inhibitors caused the accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2, which is targeted to the ubiquitin–proteasome system, and activated the antioxidant response element (ARE-dependent transcription. Paraquat also upregulated the protein level of Nrf2 without increased expression of Nrf2 mRNA, and activated the Nrf2–ARE pathway. Consequently, paraquat induced expression of Nrf2-dependent ARE-driven genes, such as γ-glutamylcysteine synthetase, catalase, and hemeoxygenase-1. Knockdown of Nrf2 or inhibition of γ-glutamylcysteine synthetase and catalase exacerbated paraquat-induced toxicity, whereas suppression of hemeoxygenase-1 did not. These data indicate that the compensatory activation of the Nrf2–ARE pathway via inhibition of 26S proteasome serves as part of a cellular defense mechanism to protect against paraquat toxicity.

  12. Compensatory role of the Nrf2-ARE pathway against paraquat toxicity: Relevance of 26S proteasome activity.

    Science.gov (United States)

    Izumi, Yasuhiko; Yamamoto, Noriyuki; Matsushima, Sayaka; Yamamoto, Takamori; Takada-Takatori, Yuki; Akaike, Akinori; Kume, Toshiaki

    2015-11-01

    Oxidative stress and the ubiquitin-proteasome system play a key role in the pathogenesis of Parkinson disease. Although the herbicide paraquat is an environmental factor that is involved in the etiology of Parkinson disease, the role of 26S proteasome in paraquat toxicity remains to be determined. Using PC12 cells overexpressing a fluorescent protein fused to the proteasome degradation signal, we report here that paraquat yielded an inhibitory effect on 26S proteasome activity without an obvious decline in 20S proteasome activity. Relative low concentrations of proteasome inhibitors caused the accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2), which is targeted to the ubiquitin-proteasome system, and activated the antioxidant response element (ARE)-dependent transcription. Paraquat also upregulated the protein level of Nrf2 without increased expression of Nrf2 mRNA, and activated the Nrf2-ARE pathway. Consequently, paraquat induced expression of Nrf2-dependent ARE-driven genes, such as γ-glutamylcysteine synthetase, catalase, and hemeoxygenase-1. Knockdown of Nrf2 or inhibition of γ-glutamylcysteine synthetase and catalase exacerbated paraquat-induced toxicity, whereas suppression of hemeoxygenase-1 did not. These data indicate that the compensatory activation of the Nrf2-ARE pathway via inhibition of 26S proteasome serves as part of a cellular defense mechanism to protect against paraquat toxicity. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  13. Neuroprotective effects of the triterpenoid, CDDO methyl amide, a potent inducer of Nrf2-mediated transcription.

    Directory of Open Access Journals (Sweden)

    Lichuan Yang

    Full Text Available The NF-E2-related factor-2 (Nrf2/antioxidant response element (ARE signaling pathway regulates phase 2 detoxification genes, including a variety of antioxidative enzymes. We tested neuroprotective effects of the synthetic triterpenoid CDDO-MA, a potent activator of the Nrf2/ARE signaling. CDDO-MA treatment of neuroblastoma SH-SY5Y cells resulted in Nrf2 upregulation and translocation from cytosol to nucleus and subsequent activation of ARE pathway genes. CDDO-MA blocked t-butylhydroperoxide-induced production of reactive oxygen species (ROS by activation of ARE genes only in wild type, but not Nrf2 knockout mouse embryonic fibroblasts. Oral administration of CDDO-MA resulted in significant protection against MPTP-induced nigrostriatal dopaminergic neurodegeneration, pathological alpha-synuclein accumulation and oxidative damage in mice. Additionally, CDDO-MA treatment in rats produced significant rescue against striatal lesions caused by the neurotoxin 3-NP, and associated increases in the oxidative damage markers malondialdehyde, F(2-Isoprostanes, 8-hydroxy-2-deoxyguanosine, 3-nitrotyrosine, and impaired glutathione homeostasis. Our results indicate that the CDDO-MA renders its neuroprotective effects through its potent activation of the Nrf2/ARE pathway, and suggest that triterpenoids may be beneficial for the treatment of neurodegenerative diseases like Parkinson's disease and Huntington's disease.

  14. Linalool attenuates lung inflammation induced by Pasteurella multocida via activating Nrf-2 signaling pathway.

    Science.gov (United States)

    Wu, Qianchao; Yu, Lijun; Qiu, Jiaming; Shen, Bingyu; Wang, Di; Soromou, Lanan Wassy; Feng, Haihua

    2014-08-01

    Pasteurellosis caused by Pasteurella multocida manifest often as respiratory infection in farmed small ruminants. Although the incidence of pasteurellosis due to P. multocida mainly takes the form of pneumonia, there is limited information on host factors that play a role in disease pathogenesis in the milieu of host-pathogen interactions. Nuclear factor-erythroid 2 related factor 2 (Nrf-2), a critical regulator for various inflammatory and immune responses by controlling oxidative stress, may play an important role in the processes of inflammation induced by P. multocida. In this study, linalool, a natural compound of the essential oils in several aromatic plant species, elevated nuclear Nrf-2 protein translocation in the A549 lung cell line and in vivo. The P. multocida-induced pro-inflammatory cytokines expression was abrogated by Nrf-2 siRNA. Postponed treatment with linalool decreased lung neutrophil accumulation and enhanced clearance of P. multocida. Furthermore, linalool significantly increased the expression of antioxidant enzymes regulated by Nrf-2 and diminished lung tissue levels of several pro-inflammatory cytokines, including tumor necrosis factor α (TNF-α) and interleukin (IL)-6. In addition, animals treated with linalool had a marked improvement in survival. These findings have uncovered that linalool acts as a novel Nrf-2 activator for a novel therapeutic strategy in pathogen-mediated lung inflammation. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Overexpression of Nrf2 protects against microcystin-induced hepatotoxicity in mice.

    Directory of Open Access Journals (Sweden)

    Yuan-Fu Lu

    Full Text Available Oxidative stress and glutathione (GSH depletion are implicated in mycocystin hepatotoxicity. To investigate the role of nuclear factor erythroid 2-related factor 2 (Nrf2 in microcystin-induced liver injury, Nrf2-null, wild-type, and Keap1-hepatocyte knockout (Keap1-HKO mice were treated with microcystin (50 μg/kg, i.p.. Blood and liver samples were collected 8 h thereafter. Microcystin increased serum alanine aminotransferase and aspartate aminotransferase activities, and caused extensive inflammation and necrosis in Nrf2-null and wild-type mice, but not in Keap1-HKO mice. Oxidative stress and inflammation are implicated in microcystin-induced hepatotoxicity, as evidenced by increased lipid peroxidation and increased expression of pro-inflammatory genes, such as neutrophil-specific chemokines mKC and MIP-2, and pro-inflammatory cytokines IL-1β and IL-6. The increased expression of these pro-inflammatory genes was attenuated in Keap1-HKO mice. Nrf2 and Nqo1 mRNA and protein were higher in Keap1-HKO mice at constitutive levels and after microcystin. To further investigate the mechanism of the protection, hepatic GSH and the mRNA of GSH-related enzymes were determined. Microcystin markedly depleted liver GSH by 60-70% in Nrf2 and WT mice but only 35% in Keap1-HKO mice. The mRNAs of GSH conjugation and peroxide reduction enzymes, such as Gstα1, Gstα4, Gstμ, and Gpx2 were higher in livers of Keap1-HKO mice, together with higher expression of the rate-limiting enzyme for GSH synthesis (Gclc. Organic anion transport polypeptides were increased by microcystin with the most increase in Keap1-HKO mice. In conclusion, this study demonstrates that higher basal levels of Nrf2 and GSH-related genes in Keap1-HKO mice prevented microcystin-induced oxidative stress and liver injury.

  16. Molecular Evolution of the Nuclear Factor (Erythroid-Derived 2)-Like 2 Gene Nrf2 in Old World Fruit Bats (Chiroptera: Pteropodidae).

    Science.gov (United States)

    Yin, Qiuyuan; Zhu, Lei; Liu, Di; Irwin, David M; Zhang, Shuyi; Pan, Yi-Hsuan

    2016-01-01

    Mammals developed antioxidant systems to defend against oxidative damage in their daily life. Enzymatic antioxidants and low molecular weight antioxidants (LMWAs) constitute major parts of the antioxidant systems. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2, encoded by the Nrf2 gene) is a central transcriptional regulator, regulating transcription, of many antioxidant enzymes. Frugivorous bats eat large amounts of fruits that contain high levels of LMWAs such as vitamin C, thus, a reliance on LMWAs might greatly reduce the need for antioxidant enzymes in comparison to insectivorous bats. Therefore, it is possible that frugivorous bats have a reduced need for Nrf2 function due to their substantial intake of diet-antioxidants. To test whether the Nrf2 gene has undergone relaxed evolution in fruit-eating bats, we obtained Nrf2 sequences from 16 species of bats, including four Old World fruit bats (Pteropodidae) and one New World fruit bat (Phyllostomidae). Our molecular evolutionary analyses revealed changes in the selection pressure acting on Nrf2 gene and identified seven specific amino acid substitutions that occurred on the ancestral lineage leading to Old World fruit bats. Biochemical experiments were conducted to examine Nrf2 in Old World fruit bats and showed that the amount of catalase, which is regulated by Nrf2, was significantly lower in the brain, heart and liver of Old World fruit bats despite higher levels of Nrf2 protein in Old World fruit bats. Computational predictions suggest that three of these seven amino acid replacements might be deleterious to Nrf2 function. Therefore, the results suggest that Nrf2 gene might have experienced relaxed constraint in Old World fruit bats, however, we cannot rule out the possibility of positive selection. Our study provides the first data on the molecular adaptation of Nrf2 gene in frugivorous bats in compensation to the increased levels of LWMAs from their fruit-diet.

  17. Suppression of NRF2–ARE activity sensitizes chemotherapeutic agent-induced cytotoxicity in human acute monocytic leukemia cells

    International Nuclear Information System (INIS)

    Peng, Hui; Wang, Huihui; Xue, Peng; Hou, Yongyong; Dong, Jian; Zhou, Tong; Qu, Weidong; Peng, Shuangqing; Li, Jin; Carmichael, Paul L.; Nelson, Bud; Clewell, Rebecca; Zhang, Qiang; Andersen, Melvin E.; Pi, Jingbo

    2016-01-01

    Nuclear factor erythroid 2-related factor 2 (NRF2), a master regulator of the antioxidant response element (ARE)-dependent transcription, plays a pivotal role in chemical detoxification in normal and tumor cells. Consistent with previous findings that NRF2–ARE contributes to chemotherapeutic resistance of cancer cells, we found that stable knockdown of NRF2 by lentiviral shRNA in human acute monocytic leukemia (AML) THP-1 cells enhanced the cytotoxicity of several chemotherapeutic agents, including arsenic trioxide (As 2 O 3 ), etoposide and doxorubicin. Using an ARE-luciferase reporter expressed in several human and mouse cells, we identified a set of compounds, including isonicotinic acid amides, isoniazid and ethionamide, that inhibited NRF2–ARE activity. Treatment of THP-1 cells with ethionamide, for instance, significantly reduced mRNA expression of multiple ARE-driven genes under either basal or As 2 O 3 -challenged conditions. As determined by cell viability and cell cycle, suppression of NRF2–ARE by ethionamide also significantly enhanced susceptibility of THP-1 and U937 cells to As 2 O 3 -induced cytotoxicity. In THP-1 cells, the sensitizing effect of ethionamide on As 2 O 3 -induced cytotoxicity was highly dependent on NRF2. To our knowledge, the present study is the first to demonstrate that ethionamide suppresses NRF2–ARE signaling and disrupts the transcriptional network of the antioxidant response in AML cells, leading to sensitization to chemotherapeutic agents. - Highlights: • Identification of novel inhibitors of ARE-dependent transcription • Suppression of NRF2–ARE sensitizes THP-1 cells to chemotherapy. • Ethionamide suppresses ARE-dependent transcriptional activity. • Ethionamide and isoniazid increase the cytotoxicity of As 2 O 3 in AML cells. • Sensitization of THP-1 cells to As 2 O 3 toxicity by ethionamide is NRF2-dependent.

  18. Nrf2 regulates mass accrual and the antioxidant endogenous response in bone differently depending on the sex and age.

    Directory of Open Access Journals (Sweden)

    Gretel Gisela Pellegrini

    Full Text Available Accumulation of reactive oxygen species (ROS is an important pathogenic mechanism underling the loss of bone mass and strength with aging and other conditions leading to osteoporosis. The transcription factor erythroid 2-related factor2 (Nrf2 plays a central role in activating the cellular response to ROS. Here, we examined the endogenous response of bone regulated by Nrf2, and its relationship with bone mass and architecture in the male and female murine skeleton. Young (3 month-old and old (15 month-old Nrf2 knockout (KO mice of either sex exhibited the expected reduction in Nrf2 mRNA expression compared to wild type (WT littermates. Nrf2 deletion did not lead to compensatory increase in Nrf1 or Nrf3, other members of this transcription factor family; and instead, Nrf1 expression was lower in KO mice. Compared to the respective WT littermate controls, female KO mice, young and old, exhibited lower expression of both detoxifying and antioxidant enzymes; young male KO mice, displayed lower expression of detoxifying enzymes but not antioxidant enzymes; and old male KO mice showed no differences in either detoxifying or antioxidant enzymes. Moreover, old male WT mice exhibited lower Nrf2 levels, and consequently lower expression of both detoxifying and antioxidant enzymes, compared to old female WT mice. These endogenous antioxidant responses lead to delayed rate of bone acquisition in female KO mice and higher bone acquisition in male KO mice as quantified by DXA and μCT, demonstrating that Nrf2 is required for full bone accrual in the female skeleton but unnecessary and even detrimental in the male skeleton. Therefore, Nrf2 regulates the antioxidant endogenous response and bone accrual differently depending on sex and age. These findings suggest that therapeutic interventions that target Nrf2 could be developed to enhance the endogenous antioxidant response in a sex- and age-selective manner.

  19. Nrf2 regulates mass accrual and the antioxidant endogenous response in bone differently depending on the sex and age

    Science.gov (United States)

    Pellegrini, Gretel Gisela; Cregor, Meloney; McAndrews, Kevin; Morales, Cynthya Carolina; McCabe, Linda Doyle; McCabe, George P.; Peacock, Munro; Burr, David; Weaver, Connie; Bellido, Teresita

    2017-01-01

    Accumulation of reactive oxygen species (ROS) is an important pathogenic mechanism underling the loss of bone mass and strength with aging and other conditions leading to osteoporosis. The transcription factor erythroid 2-related factor2 (Nrf2) plays a central role in activating the cellular response to ROS. Here, we examined the endogenous response of bone regulated by Nrf2, and its relationship with bone mass and architecture in the male and female murine skeleton. Young (3 month-old) and old (15 month-old) Nrf2 knockout (KO) mice of either sex exhibited the expected reduction in Nrf2 mRNA expression compared to wild type (WT) littermates. Nrf2 deletion did not lead to compensatory increase in Nrf1 or Nrf3, other members of this transcription factor family; and instead, Nrf1 expression was lower in KO mice. Compared to the respective WT littermate controls, female KO mice, young and old, exhibited lower expression of both detoxifying and antioxidant enzymes; young male KO mice, displayed lower expression of detoxifying enzymes but not antioxidant enzymes; and old male KO mice showed no differences in either detoxifying or antioxidant enzymes. Moreover, old male WT mice exhibited lower Nrf2 levels, and consequently lower expression of both detoxifying and antioxidant enzymes, compared to old female WT mice. These endogenous antioxidant responses lead to delayed rate of bone acquisition in female KO mice and higher bone acquisition in male KO mice as quantified by DXA and μCT, demonstrating that Nrf2 is required for full bone accrual in the female skeleton but unnecessary and even detrimental in the male skeleton. Therefore, Nrf2 regulates the antioxidant endogenous response and bone accrual differently depending on sex and age. These findings suggest that therapeutic interventions that target Nrf2 could be developed to enhance the endogenous antioxidant response in a sex- and age-selective manner. PMID:28152064

  20. Nrf2/p62 Signaling in Apoptosis Resistance and Its Role in Cadmium-induced Carcinogenesis*

    Science.gov (United States)

    Son, Young-Ok; Pratheeshkumar, Poyil; Roy, Ram Vinod; Hitron, John Andrew; Wang, Lei; Zhang, Zhuo; Shi, Xianglin

    2014-01-01

    The cadmium-transformed human lung bronchial epithelial BEAS-2B cells exhibit a property of apoptosis resistance as compared with normal non-transformed BEAS-2B cells. The level of basal reactive oxygen species (ROS) is extremely low in transformed cells in correlation with elevated expressions of both antioxidant enzymes (catalase, SOD1, and SOD2) and antiapoptotic proteins (Bcl-2/Bcl-xL). Moreover, Nrf2 and p62 are highly expressed in these transformed cells. The knockdown of Nrf2 or p62 by siRNA enhances ROS levels and cadmium-induced apoptosis. The binding activities of Nrf2 on the antioxidant response element promoter regions of p62/Bcl-2/Bcl-xL were dramatically increased in the cadmium-exposed transformed cells. Cadmium exposure increased the formation of LC3-II and the frequency of GFP-LC3 punctal cells in non-transformed BEAS-2B cells, whereas these increases are not shown in transformed cells, an indication of autophagy deficiency of transformed cells. Furthermore, the expression levels of Nrf2 and p62 are dramatically increased during chronic long term exposure to cadmium in the BEAS-2B cells as well as antiapoptotic proteins and antioxidant enzymes. These proteins are overexpressed in the tumor tissues derived from xenograft mouse models. Moreover, the colony growth is significantly attenuated in the transformed cells by siRNA transfection specific for Nrf2 or p62. Taken together, this study demonstrates that cadmium-transformed cells have acquired autophagy deficiency, leading to constitutive p62 and Nrf2 overexpression. These overexpressions up-regulate the antioxidant proteins catalase and SOD and the antiapoptotic proteins Bcl-2 and Bcl-xL. The final consequences are decrease in ROS generation, apoptotic resistance, and increased cell survival, proliferation, and tumorigenesis. PMID:25157103

  1. Licochalcone A Upregulates Nrf2 Antioxidant Pathway and Thereby Alleviates Acetaminophen-Induced Hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Hongming Lv

    2018-03-01

    Full Text Available Acetaminophen (APAP overdose-induced fatal hepatotoxicity is majorly characterized by overwhelmingly increased oxidative stress while enhanced nuclear factor-erythroid 2-related factor 2 (Nrf2 is involved in prevention of hepatotoxicity. Although Licochalcone A (Lico A upregulates Nrf2 signaling pathway against oxidative stress-triggered cell injury, whether it could protect from APAP-induced hepatotoxicity by directly inducing Nrf2 activation is still poorly elucidated. This study aims to explore the protective effect of Lico A against APAP-induced hepatotoxicity and its underlying molecular mechanisms. Our findings indicated that Lico A effectively decreased tert-butyl hydroperoxide (t-BHP- and APAP-stimulated cell apoptosis, mitochondrial dysfunction and reactive oxygen species generation and increased various anti-oxidative enzymes expression, which is largely dependent on upregulating Nrf2 nuclear translocation, reducing the Keap1 protein expression, and strengthening the antioxidant response element promoter activity. Meanwhile, Lico A dramatically protected against APAP-induced acute liver failure by lessening the lethality; alleviating histopathological liver changes; decreasing the alanine transaminase and aspartate aminotransferase levels, malondialdehyde formation, myeloperoxidase level and superoxide dismutase depletion, and increasing the GSH-to-GSSG ratio. Furthermore, Lico A not only significantly modulated apoptosis-related protein by increasing Bcl-2 expression, and decreasing Bax and caspase-3 cleavage expression, but also efficiently alleviated mitochondrial dysfunction by reducing c-jun N-terminal kinase phosphorylation and translocation, inhibiting Bax mitochondrial translocation, apoptosis-inducing factor and cytochrome c release. However, Lico A-inhibited APAP-induced the lethality, histopathological changes, hepatic apoptosis, and mitochondrial dysfunction in WT mice were evidently abrogated in Nrf2-/- mice. These

  2. Essential role of Nrf2 in keratinocyte protection from UVA by quercetin

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Shintarou [Majors of Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki (Japan); Warabi, Eiji, E-mail: warabi-e@md.tsukuba.ac.jp [Majors of Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki (Japan); Yanagawa, Toru; Ma, Dongmei [Majors of Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki (Japan); Itoh, Ken [Department of Stress Response Science, Hirosaki University Graduate School of Medicine, Hirosaki (Japan); Ishii, Yoshiyuki; Kawachi, Yasuhiro; Ishii, Tetsuro [Majors of Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki (Japan)

    2009-09-11

    Much of the cell injury caused by ultraviolet A (UVA) irradiation is associated with oxidative stress. Quercetin is a major natural polyphenol that is known to protect cells from UVA-induced damage. Here, we investigated the molecular mechanism of this protection. Quercetin pretreatment strongly suppressed UVA-induced apoptosis in human keratinocyte HaCaT cells, markedly increased protein levels of the transcription factor Nrf2, induced the expression of antioxidative genes, and dramatically reduced the production of reactive oxygen species following UVA irradiation. Importantly, these beneficial effects were greatly attenuated by downregulating Nrf2 expression. Thus, quercetin protects cells from UVA damage mainly by elevating intracellular antioxidative activity via the enhanced accumulation of a transcription factor for antioxidant genes, Nrf2.

  3. Gastrodin protects against LPS-induced acute lung injury by activating Nrf2 signaling pathway.

    Science.gov (United States)

    Zhang, Zhuo; Zhou, Jie; Song, Daqiang; Sun, Yuhong; Liao, Changli; Jiang, Xian

    2017-05-09

    Gastrodin (GAS), a phenolic glucoside derived from Gastrodiaelata Blume, has been reported to have anti-inflammatory effect. The aim of this study was to investigate the effects of GAS on LPS-induced acute lung injury in mice. ALI was induced by the intranasal administration of LPS and GAS was given 1 h or 12 h after LPS treatment. The results indicated that GAS treatment markedly attenuated the damage of lung injury induced by LPS. GAS attenuated the activity of myeloperoxidase (MPO) and down-regulated the levels of pro-inflammatory cytokines TNF-α, IL-6 and IL-1β in BALF. LPS-induced lung edema and lung function were also reversed by GAS. Furthermore, GAS was found to inhibit LPS-induced inflammatory cells infiltration. In addition, treatment of GAS inhibited LPS-induced NF-κB activation and up-regulated the expression of Nrf2 and HO-1. In conclusion, our results indicated that GAS had anti-inflammatory effects on LPS-induced acute lung injury. The anti-inflammatory mechanism of GAS was through the inhibition of NF-κB and activation of Nrf2 signaling pathways.

  4. Preventive Effects of Velvet Antler (Cervus elaphus against Lipopolysaccharide-Induced Acute Lung Injury in Mice by Inhibiting MAPK/NF-κB Activation and Inducing AMPK/Nrf2 Pathways

    Directory of Open Access Journals (Sweden)

    Jui-Shu Chang

    2018-01-01

    Full Text Available Velvet antler (Cervus elaphus is a typical traditional animal medicine. It is considered to have various pharmacological effects including stimulation of the immune system, increase in the physical strength, and enhancement of sexual function. This paper aims to investigate the aqueous extract of velvet antler (AVA in the mouse models of LPS-induced ALI. Inhibition of NO, TNF-α, IL-1β, IL-6, and IL-10 productions contributes to the attenuation of LPS-induced lung inflammation by AVA. A 5-day pretreatment of AVA prevented histological alterations and enhanced antioxidant enzyme activity in lung tissues. AVA significantly reduced the material (total number of cells and proteins in the BALF. Western blot analysis revealed that the expression of iNOS and COX-2 and phosphorylation of IκB-α and MAPKs proteins are blocked in LPS-stimulated macrophages as well as LPS-induced lung injury in mice. Consistent with this concept, the phosphorylation of CaMKKβ, LKB1, AMPK, Nrf2, and HO-1 was activated after AVA treatment. The results from this study indicate AVA has anti-inflammatory effects in vivo and AVA is a potential model for the development of health food. In addition, its pathways may be at least partially associated with inhibiting MAPK/NF-κB activation and upregulating AMPK/Nrf2 pathways and the regulation of antioxidant enzyme activity.

  5. Repeated Nrf2 stimulation using sulforaphane protects fibroblasts from ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Mathew, Sherin T.; Bergström, Petra; Hammarsten, Ola, E-mail: ola.hammarsten@clinchem.gu.se

    2014-05-01

    Most of the cytotoxicity induced by ionizing radiation is mediated by radical-induced DNA double-strand breaks. Cellular protection from free radicals can be stimulated several fold by sulforaphane-mediated activation of the transcription factor Nrf2 that regulates more than 50 genes involved in the detoxification of reactive substances and radicals. Here, we report that repeated sulforaphane treatment increases radioresistance in primary human skin fibroblasts. Cells were either treated with sulforaphane for four hours once or with four-hour treatments repeatedly for three consecutive days prior to radiation exposure. Fibroblasts exposed to repeated-sulforaphane treatment showed a more pronounced dose-dependent induction of Nrf2-regulated mRNA and reduced amount of radiation-induced free radicals compared with cells treated once with sulforaphane. In addition, radiation- induced DNA double-strand breaks measured by gamma-H2AX foci were attenuated following repeated sulforaphane treatment. As a result, cellular protection from ionizing radiation measured by the 5-ethynyl-2′-deoxyuridine (EdU) assay was increased, specifically in cells exposed to repeated sulforaphane treatment. Sulforaphane treatment was unable to protect Nrf2 knockout mouse embryonic fibroblasts, indicating that the sulforaphane-induced radioprotection was Nrf2-dependent. Moreover, radioprotection by repeated sulforaphane treatment was dose-dependent with an optimal effect at 10 uM, whereas both lower and higher concentrations resulted in lower levels of radioprotection. Our data indicate that the Nrf2 system can be trained to provide further protection from radical damage. - Highlights: • Repeated treatment with sulforaphane protects fibroblasts from ionizing radiation • Repeated sulforaphane treatment attenuates radiation induced ROS and DNA damage • Sulforaphane mediated protection is Nrf2 dependent.

  6. Erdosteine protects HEI-OC1 auditory cells from cisplatin toxicity through suppression of inflammatory cytokines and induction of Nrf2 target proteins

    International Nuclear Information System (INIS)

    Kim, Se-Jin; Park, Channy; Lee, Joon No; Lim, Hyewon; Hong, Gi-yeon; Moon, Sung K.; Lim, David J.; Choe, Seong-Kyu; Park, Raekil

    2015-01-01

    Cisplatin has many adverse effects, which are a major limitation to its use, including ototoxicity, neurotoxicity, and nephrotoxicity. This study aims to elucidate the protective mechanisms of erdosteine against cisplatin in HEI-OC1 cells. Pretreatment with erdosteine protects HEI-OC1 cells from cisplatin-medicated apoptosis, which is characterized by increase in nuclear fragmentation, DNA laddering, sub-G 0 /G 1 phase, H2AX phosphorylation, PARP cleavage, and caspase-3 activity. Erdosteine significantly suppressed the production of reactive nitrogen/oxygen species and pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 in cisplatin-treated cells. Studies using pharmacologic inhibitors demonstrated that phosphatidylinositol-3-kinases (PI3K) and protein kinase B (Akt) have protective roles in the action of erdosteine against cisplatin in HEI-OC1 cells. In addition, pretreatment with erdosteine clearly suppressed the phosphorylation of p53 (Ser15) and expression of p53-upregulated modulator of apoptosis. Erdosteine markedly induces expression of NF-E2-related factor 2 (Nrf2), which may contribute to the increase in expression of glutathione redox genes γ-L-glutamate-L-cysteine-ligase catalytic and γ-L-glutamate-L-cysteine-ligase modifier subunits, as well as in the antioxidant genes HO-1 and SOD2 in cisplatin-treated HEI-OC1 cells. Furthermore, the increase in expression of phosphorylated p53 induced by cisplatin is markedly attenuated by pretreatment with erdosteine in the mitochondrial fraction. This increased expression may inhibit the cytosolic expression of the apoptosis-inducing factor, cytochrome c, and Bax/Bcl-xL ratio. Thus, our results suggest that treatment with erdosteine is significantly attenuated cisplatin-induced damage through the activation of Nrf2-dependent antioxidant genes, inhibition of pro-inflammatory cytokines, activation of the PI3K/Akt signaling, and mitochondrial-related inhibition of pro

  7. Hydrogen peroxide prevents vascular calcification induced ROS production by regulating Nrf-2 pathway.

    Science.gov (United States)

    Zhang, Wensong; Li, Yi; Ding, Hanlu; Du, Yaqin; Wang, Li

    2016-08-01

    Although vascular calcification in end-stage renal disease (ESRD) represents a ubiquitous human health problem, effective therapies with limited side effects are still lacking, and the precise mechanisms are not fully understood. The Nrf-2/ARE pathway is a pivotal to regulate anti-oxidative responses in vascular calcification upon ESRD. Although Nrf-2 plays a crucial role in atherosclerosis, pulmonary fibrosis, and brain ischemia, the effect of Nrf-2 and oxidative stress on vascular calcification in ESRD patients is still unclear. The aim of this research was to study the protective role of hydrogen peroxide in vascular calcification and the mechanism of Nrf-2 and oxidative stress on vascular calcification. Here we used the rat vascular smooth muscle cell model of β-glycerophosphate-induced calcification resembling vascular calcification in ESRD to investigate the therapeutic effect of 0.01 mM hydrogen peroxide on vascular calcification and further explores the possible underlying mechanisms. Our current report shows the in vitro role of 0.01 mM hydrogen peroxide in protecting against intracellular ROS accumulation upon vascular calcification. Both hydrogen peroxide and sulforaphane pretreatment reduced ROS production, increased the expression of Nrf-2, and decreased the expression of Runx2 following calcification. Our study demonstrates that 0.01 mM hydrogen peroxide can effectively protect rat aortic vascular smooth muscle cells against oxidative stress by preventing vascular calcification induced ROS production through Nrf-2 pathway. These data might define an antioxidant role of hydrogen peroxide in vascular calcification upon ESRD.

  8. PCB 126 toxicity is modulated by cross-talk between caveolae and Nrf2 signaling

    Energy Technology Data Exchange (ETDEWEB)

    Petriello, Michael C. [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Han, Sung Gu [University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Department of Food Science and Biotechnology of Animal Resources, College of Animal Bioscience and Technology, Konkuk University, Seoul 143-701 (Korea, Republic of); Newsome, Bradley J. [University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Department of Chemistry, College of Arts and Sciences, University of Kentucky, Lexington, KY 40506 (United States); Hennig, Bernhard [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, KY 40506 (United States)

    2014-06-01

    Environmental toxicants such as polychlorinated biphenyls (PCBs) have been implicated in the promotion of multiple inflammatory disorders including cardiovascular disease, but information regarding mechanisms of toxicity and cross-talk between relevant cell signaling pathways is lacking. To examine the hypothesis that cross-talk between membrane domains called caveolae and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathways alters PCB-induced inflammation, caveolin-1 was silenced in vascular endothelial cells, resulting in a decreased PCB-induced inflammatory response. Cav-1 silencing (siRNA treatment) also increased levels of Nrf2-ARE transcriptional binding, resulting in higher mRNA levels of the antioxidant genes glutathione s-transferase and NADPH dehydrogenase quinone-1 in both vehicle and PCB-treated systems. Along with this upregulated antioxidant response, Cav-1 siRNA treated cells exhibited decreased mRNA levels of the Nrf2 inhibitory protein Keap1 in both vehicle and PCB-treated samples. Silencing Cav-1 also decreased protein levels of Nrf2 inhibitory proteins Keap1 and Fyn kinase, especially in PCB-treated cells. Further, endothelial cells from wildtype and Cav-1 −/− mice were isolated and treated with PCB to better elucidate the role of functional caveolae in PCB-induced endothelial inflammation. Cav-1 −/− endothelial cells were protected from PCB-induced cellular dysfunction as evidenced by decreased vascular cell adhesion molecule (VCAM-1) protein induction. Compared to wildtype cells, Cav-1 −/− endothelial cells also allowed for a more effective antioxidant response, as observed by higher levels of the antioxidant genes. These data demonstrate novel cross-talk mechanisms between Cav-1 and Nrf2 and implicate the reduction of Cav-1 as a protective mechanism for PCB-induced cellular dysfunction and inflammation. - Highlights: • Reduction of caveolin-1 protein protects against polychlorinated biphenyl toxicity. • Decreasing

  9. Allantopyrone A activates Keap1-Nrf2 pathway and protects PC12 cells from oxidative stress-induced cell death.

    Science.gov (United States)

    Uesugi, Shota; Muroi, Makoto; Kondoh, Yasumitsu; Shiono, Yoshihito; Osada, Hiroyuki; Kimura, Ken-Ichi

    2017-04-01

    Keap1-Nrf2 system is known as a sensor of electrophilic compounds, and protects cells from oxidative stress through induction of various antioxidant enzymes. We found by proteomic analysis that allantopyrone A, a metabolite isolated from an endophytic fungus, upregulates the expression of proteins that are regulated by the transcription factor Nrf2. Indeed, allantopyrone A increased the antioxidant enzyme heme oxygenase-1 in PC12 cells. Moreover, it induced localization of Nrf2 in the nucleus. Affinity purification of allantopyrone A-binding protein showed that this compound could bind directly to Keap1. Allantopyrone A suppressed intracellular reactive oxygen species level and cell death induced by H 2 O 2 in PC12 cells. These results indicate that allantopyrone A protects PC12 cells from oxidative stress-induced cell death through direct binding with Keap1 and activation of the Keap1-Nrf2 pathway.

  10. Involvement of the Nrf2-proteasome pathway in the endoplasmic reticulum stress response in pancreatic β-cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sanghwan; Hur, Eu-gene [Yeungnam University, College of Pharmacy, Gyeongsan-si, Gyeongsangbuk-do 712‐749 (Korea, Republic of); Ryoo, In-geun; Jung, Kyeong-Ah [The Catholic University of Korea, College of Pharmacy, Wonmi-gu, Bucheon, Gyeonggi-do 420‐743 (Korea, Republic of); Kwak, Jiyeon [Inha University, College of Medicine, 253 Yonghyun-dong, Nam-gu, Incheon 402‐751 (Korea, Republic of); Kwak, Mi-Kyoung, E-mail: mkwak@catholic.ac.kr [The Catholic University of Korea, College of Pharmacy, Wonmi-gu, Bucheon, Gyeonggi-do 420‐743 (Korea, Republic of)

    2012-11-01

    The ubiquitin-proteasome system plays a central role in protein quality control through endoplasmic reticulum (ER)-associated degradation (ERAD) of unfolded and misfolded proteins. NF-E2‐related factor 2 (Nrf2) is a transcription factor that controls the expression of an array of phase II detoxification and antioxidant genes. Nrf2 signaling has additionally been shown to upregulate the expression of the proteasome catalytic subunits in several cell types. Here, we investigated the role of Nrf2 in tunicamycin-induced ER stress using a murine insulinoma β-cell line, βTC-6. shRNA-mediated silencing of Nrf2 expression in βTC-6 cells significantly increased tunicamycin-induced cytotoxicity, elevated the expression of the pro-apoptotic ER stress marker Chop10, and inhibited tunicamycin-inducible expression of the proteasomal catalytic subunits Psmb5 and Psmb6. The effects of 3H-1,2-dithiole-3-thione (D3T), a small molecule Nrf2 activator, on ER stress were also examined in βTC-6 cells. D3T pretreatment reduced tunicamycin cytotoxicity and attenuated the tunicamycin-inducible Chop10 and protein kinase RNA-activated‐like ER kinase (Perk). The protective effect of D3T was shown to be associated with increased ERAD. D3T increased the expression of Psmb5 and Psmb6 and elevated chymotrypsin-like peptidase activity; proteasome inhibitor treatment blocked D3T effects on tunicamycin cytotoxicity and ER stress marker changes. Similarly, silencing of Nrf2 abolished the protective effect of D3T against ER stress. These results indicate that the Nrf2 pathway contributes to the ER stress response in pancreatic β-cells by enhancing proteasome-mediated ERAD. -- Highlights: ► Nrf2 silencing in pancreatic β-cells enhanced tunicamycin-mediated ER stress. ► Expression of the proteasome was inducible by Nrf2 signaling. ► Nrf2 activator D3T protected β-cells from tunicamycin-mediated ER stress. ► Protective effect of D3T was associated with Nrf2-dependent proteasome

  11. Role of Nrf2 antioxidant defense in mitigating cadmium-induced oxidative stress in the olfactory system of zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lu; Gallagher, Evan P., E-mail: evang3@uw.edu

    2013-01-15

    Exposure to trace metals can disrupt olfactory function in fish leading to a loss of behaviors critical to survival. Cadmium (Cd) is an olfactory toxicant that elicits cellular oxidative stress as a mechanism of toxicity while also inducing protective cellular antioxidant genes via activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. However, the molecular mechanisms of Cd-induced olfactory injury have not been characterized. In the present study, we investigated the role of the Nrf2-mediated antioxidant defense pathway in protecting against Cd-induced olfactory injury in zebrafish. A dose-dependent induction of Nrf2-regulated antioxidant genes associated with cellular responses to oxidative stress was observed in the olfactory system of adult zebrafish following 24 h Cd exposure. Zebrafish larvae exposed to Cd for 3 h showed increased glutathione S-transferase pi (gst pi), glutamate–cysteine ligase catalytic subunit (gclc), heme oxygenase 1 (hmox1) and peroxiredoxin 1 (prdx1) mRNA levels indicative of Nrf2 activation, and which were blocked by morpholino-mediated Nrf2 knockdown. The inhibition of antioxidant gene induction in Cd-exposed Nrf2 morphants was associated with disruption of olfactory driven behaviors, increased cell death and loss of olfactory sensory neurons (OSNs). Nrf2 morphants also exhibited a downregulation of OSN-specific genes after Cd exposure. Pre-incubation of embryos with sulforaphane (SFN) partially protected against Cd-induced olfactory tissue damage. Collectively, our results indicate that oxidative stress is an important mechanism of Cd-mediated injury in the zebrafish olfactory system. Moreover, the Nrf2 pathway plays a protective role against cellular oxidative damage and is important in maintaining zebrafish olfactory function. -- Highlights: ► Oxidative stress is an important mechanism of Cd-mediated olfactory injury. ► Cd induces antioxidant gene expression in the zebrafish olfactory system. ► The

  12. The neuroprotective effects of α-iso-cubebene on dopaminergic cell death: involvement of CREB/Nrf2 signaling.

    Science.gov (United States)

    Park, Sun Young; Son, Beung Gu; Park, Young Hoon; Kim, Cheol-Min; Park, Geuntae; Choi, Young-Whan

    2014-09-01

    As a part of ongoing studies to elucidate pharmacologically active components of Schisandra chinensis, we isolated and studied α-iso-cubebene. The neuroprotective mechanisms of α-iso-cubebene in human neuroblastoma SH-SY5Y cells were investigated. α-Iso-cubebene significantly inhibited cytotoxicity and apoptosis due to 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in dopaminergic SH-SY5Y cells. Pretreatment of cells with α-iso-cubebene reduced intracellular accumulation of ROS and calcium in response to 6-OHDA. The neuroprotective effects of α-iso-cubebene were found to result from protecting the mitochondrial membrane potential. Notably, α-iso-cubebene inhibited the release of apoptosis-inducing factor from the mitochondria into the cytosol and nucleus after 6-OHDA treatment. α-Iso-cubebene also induced the activation of PKA/PKB/CREB/Nrf2 and suppressed 6-OHDA-induced neurotoxicity. α-Iso-cubebene was found to induce phosphorylation of PKA and PKB and activate Nrf2 and CREB signaling pathways in a dose-dependent manner. Additionally, α-iso-cubebene stimulated the expression of the antioxidant response genes NQO1 and HO-1. Finally, α-iso-cubebene-mediated neuroprotective effects were found to be reversible after transfection with CREB and Nrf2 small interfering RNAs.

  13. Activation of Nrf2 protects against triptolide-induced hepatotoxicity.

    Directory of Open Access Journals (Sweden)

    Jia Li

    Full Text Available Triptolide, the major active component of Tripterygium wilfordii Hook f. (TWHF, has a wide range of pharmacological activities. However, the toxicities of triptolide, particularly the hepatotoxicity, limit its clinical application. The hepatotoxicity of triptolide has not been well characterized yet. The aim of this study was to investigate the role of NF-E2-related factor 2 (Nrf2 in triptolide-induced toxicity and whether activation of Nrf2 could protect against triptolide-induced hepatotoxicity. The results showed that triptolide caused oxidative stress and cell damage in HepG2 cells, and these toxic effects could be aggravated by Nrf2 knockdown or be counteracted by overexpression of Nrf2. Treatment with a typical Nrf2 agonist, sulforaphane (SFN, attenuated triptolide-induced liver dysfunction, structural damage, glutathione depletion and decrease in antioxidant enzymes in BALB/C mice. Moreover, the hepatoprotective effect of SFN on triptolide-induced liver injury was associated with the activation of Nrf2 and its downstream targets. Collectively, these results indicate that Nrf2 activation protects against triptolide-induced hepatotoxicity.

  14. Neuroprotective effect of melatonin against ischemia is partially mediated by alpha-7 nicotinic receptor modulation and HO-1 overexpression.

    Science.gov (United States)

    Parada, Esther; Buendia, Izaskun; León, Rafael; Negredo, Pilar; Romero, Alejandro; Cuadrado, Antonio; López, Manuela G; Egea, Javier

    2014-03-01

    Melatonin has been widely studied as a protective agent against oxidative stress. However, the molecular mechanisms underlying neuroprotection in neurodegeneration and ischemic stroke are not yet well understood. In this study, we evaluated the neuroprotective/antioxidant mechanism of action of melatonin in organotypic hippocampal cultures (OHCs) as well as in photothrombotic stroke model in vivo. Melatonin (0.1, 1, and 10 μM) incubated postoxygen and glucose deprivation (OGD) showed a concentration-dependent protection; maximum protection was achieved at 10 μM (90% protection). Next, OHCs were exposed to 10 μM melatonin at different post-OGD times; the protective effect of melatonin was maintained at 0, 1, and 2 hr post-OGD treatment, but it was lost at 6 hr post-OGD. The protective effect of melatonin and the reduction in OGD-induced ROS were prevented by luzindole (melatonin antagonist) and α-bungarotoxin (α-Bgt, a selective α7 nAChR antagonist). In Nrf2 knockout mice, the protective effect of melatonin was reduced by 40% compared with controls. Melatonin, incubated 0, 1, and 2 hr post-OGD, increased the expression of heme oxygenase-1 (HO-1), and this overexpression was prevented by luzindole and α-bungarotoxin. Finally, administration of 15 mg/kg melatonin following the induction of photothrombotic stroke in vivo, reduced infarct size (50%), and improved motor skills; this effect was partially lost in 0.1 mg/kg methyllycaconitine (MLA, selective α7 nAChR antagonist)-treated mice. Taken together, these results demonstrate that postincubation of melatonin provides a protective effect that, at least in part, depends on nicotinic receptor activation and overexpression of HO-1. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Soluble factors from stellate cells induce pancreatic cancer cell proliferation via Nrf2-activated metabolic reprogramming and ROS detoxification.

    Science.gov (United States)

    Wu, Yuan Seng; Looi, Chung Yeng; Subramaniam, Kavita S; Masamune, Atsushi; Chung, Ivy

    2016-06-14

    Pancreatic stellate cells (PSC), a prominent stromal cell, contribute to the progression of pancreatic ductal adenocarcinoma (PDAC). We aim to investigate the mechanisms by which PSC promote cell proliferation in PDAC cell lines, BxPC-3 and AsPC-1. PSC-conditioned media (PSC-CM) induced proliferation of these cells in a dose- and time-dependent manner. Nrf2 protein was upregulated and subsequently, its transcriptional activity was increased with greater DNA binding activity and transcription of target genes. Downregulation of Nrf2 led to suppression of PSC-CM activity in BxPC-3, but not in AsPC-1 cells. However, overexpression of Nrf2 alone resulted in increased cell proliferation in both cell lines, and treatment with PSC-CM further enhanced this effect. Activation of Nrf2 pathway resulted in upregulation of metabolic genes involved in pentose phosphate pathway, glutaminolysis and glutathione biosynthesis. Downregulation and inhibition of glucose-6-phosphate-dehydrogenase with siRNA and chemical approaches reduced PSC-mediated cell proliferation. Among the cytokines present in PSC-CM, stromal-derived factor-1 alpha (SDF-1α) and interleukin-6 (IL-6) activated Nrf2 pathway to induce cell proliferation in both cells, as shown with neutralization antibodies, recombinant proteins and signaling inhibitors. Taken together, SDF-1α and IL-6 secreted from PSC induced PDAC cell proliferation via Nrf2-activated metabolic reprogramming and ROS detoxification.

  16. Anti-Inflammatory Therapy Modulates Nrf2-Keap1 in Kidney from Rats with Diabetes

    Directory of Open Access Journals (Sweden)

    Abraham Said Arellano-Buendía

    2016-01-01

    Full Text Available This study addressed the relationship of proinflammatory cytokines and Nrf2-Keap1 system in diabetic nephropathy. The experimental groups were control, diabetic, and diabetic treated with mycophenolate mofetil (MMF. The renal function, proinflammatory and profibrotic cytokines, oxidative stress, morphology, and nephrin expression were assessed. Diabetic group showed impaired renal function in association with oxidative stress and decreased Nrf2 nuclear translocation. These results were associated with increased mesangial matrix index, interstitial fibrosis, and increased nephrin expression in cortex and urine excretion. Additionally, interleukin-1β, IL-6, and transforming growth factor-β1 were increased in plasma and kidney. MMF treatment conserved renal function, prevented renal structural alterations, and partially prevented the proinflammatory and profibrotic cytokines overexpression. Despite that MMF treatment induced nephrin overexpression in renal tissue, preventing its urinary loss. MMF salutary effects were associated with a partial prevention of oxidative stress, increased Nrf2 nuclear translocation, and conservation of antioxidant enzymes in renal tissue. In conclusion, our results confirm that inflammation is a key factor in the progression of diabetic nephropathy and suggest that treatment with MMF protects the kidney by an antioxidant mechanism, possibly regulated at least in part by the Nrf2/Keap1 system, in addition to its well-known anti-inflammatory effects.

  17. Dose-dependent transitions in Nrf2-mediated adaptive response and related stress responses to hypochlorous acid in mouse macrophages

    International Nuclear Information System (INIS)

    Woods, Courtney G.; Fu Jingqi; Xue Peng; Hou Yongyong; Pluta, Linda J.; Yang Longlong; Zhang Qiang; Thomas, Russell S.; Andersen, Melvin E.; Pi Jingbo

    2009-01-01

    Hypochlorous acid (HOCl) is potentially an important source of cellular oxidative stress. Human HOCl exposure can occur from chlorine gas inhalation or from endogenous sources of HOCl, such as respiratory burst by phagocytes. Transcription factor Nrf2 is a key regulator of cellular redox status and serves as a primary source of defense against oxidative stress. We recently demonstrated that HOCl activates Nrf2-mediated antioxidant response in cultured mouse macrophages in a biphasic manner. In an effort to determine whether Nrf2 pathways overlap with other stress pathways, gene expression profiling was performed in RAW 264.7 macrophages exposed to HOCl using whole genome mouse microarrays. Benchmark dose (BMD) analysis on gene expression data revealed that Nrf2-mediated antioxidant response and protein ubiquitination were the most sensitive biological pathways that were activated in response to low concentrations of HOCl (< 0.35 mM). Genes involved in chromatin architecture maintenance and DNA-dependent transcription were also sensitive to very low doses. Moderate concentrations of HOCl (0.35 to 1.4 mM) caused maximal activation of the Nrf2 pathway and innate immune response genes, such as IL-1β, IL-6, IL-10 and chemokines. At even higher concentrations of HOCl (2.8 to 3.5 mM) there was a loss of Nrf2-target gene expression with increased expression of numerous heat shock and histone cluster genes, AP-1-family genes, cFos and Fra1 and DNA damage-inducible Gadd45 genes. These findings confirm an Nrf2-centric mechanism of action of HOCl in mouse macrophages and provide evidence of interactions between Nrf2, inflammatory, and other stress pathways.

  18. l-carnitine preserves cardiac function by activating p38 MAPK/Nrf2 signalling in hearts exposed to irradiation.

    Science.gov (United States)

    Fan, Zhigang; Han, Yang; Ye, Yuanpeng; Liu, Chao; Cai, Hui

    2017-06-05

    Radiation-induced heart damage (RIHD) is now considered to be one of the causes of mortality in cancer patients undergoing radiotherapy. Cardiac function impairments are clinical manifestations of RIHD. L-carnitine shows protective effects against irradiation and heart disease. This study was aimed to investigate the cardioprotective effects and potential molecular mechanisms of L-carnitine against RIHD. Mouse hearts were exposed to γ-radiation to induce RIHD. L-carnitine at doses of 100mg/Kg and 200mg/Kg was used to treat animals intraperitoneally. Additionally, a specific inhibitor of p38 MAPK was used to treat animals by intraperitoneal injections. Cardiac systolic/diastolic functions were determined using invasive hemodynamic methods; myocyte apoptosis was assessed using the TUNEL assay; intracellular reactive oxygen species production was measured using DHE staining; and western blotting was used to evaluate the phosphorylation of p38MAPK, phosphorylation of Nrf2, and expression levels of HO1, NQO1, caspase3 and bax. L-carnitine treatments inhibited irradiation induced cardiac function impairments. Radiation exposure induced myocyte apoptosis and reactive oxygen species production, which were attenuated by L-carnitine treatments. However, administration of a p38 MAPK inhibitor (SB203580) dramatically impaired L-carnitine's effect on attenuating apoptosis, reactive oxygen species accumulation and cardiac functions in irradiated hearts. Our study showed that L-carnitine administration activated p38MAPK/Nrf2 signalling, initiating the expression of HO1 and NQO1, which have anti-apoptotic and anti-oxidative effects, respectively. In conclusion, L-carnitine attenuates cardiac function loss by inhibiting reactive oxygen species production and apoptosis in hearts exposed to radiation. The cardioprotective effects of L-carnitine were mediated by p38MAPK/Nrf2 signalling. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Hydrogen Gas Inhalation Attenuates Seawater Instillation-Induced Acute Lung Injury via the Nrf2 Pathway in Rabbits.

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    Diao, Mengyuan; Zhang, Sheng; Wu, Lifeng; Huan, Le; Huang, Fenglou; Cui, Yunliang; Lin, Zhaofen

    2016-12-01

    Seawater instillation-induced acute lung injury involves oxidative stress and apoptosis. Although hydrogen gas inhalation is reportedly protective in multiple types of lung injury, the effect of hydrogen gas inhalation on seawater instillation-induced acute lung injury remains unknown. This study investigated the effect of hydrogen gas on seawater instillation-induced acute lung injury and explored the mechanisms involved. Rabbits were randomly assigned to control, hydrogen (2 % hydrogen gas inhalation), seawater (3 mL/kg seawater instillation), and seawater + hydrogen (3 mL/kg seawater instillation + 2 % hydrogen gas inhalation) groups. Arterial partial oxygen pressure and lung wet/dry weight ratio were detected. Protein content in bronchoalveolar lavage fluid (BALF) and serum as well as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 levels were determined. Hematoxylin-eosin staining was used to monitor changes in lung specimens, and malondialdehyde (MDA) content and myeloperoxidase (MPO) activity were assayed. In addition, NF-E2-related factor (Nrf) 2 and heme oxygenase (HO)-1 mRNA and protein expression were measured, and apoptosis was assessed by measuring caspase-3 expression and using terminal deoxy-nucleotidyl transferase dUTP nick end-labeling (TUNEL) staining. Hydrogen gas inhalation markedly improved lung endothelial permeability and decreased both MDA content and MPO activity in lung tissue; these changes were associated with decreases in TNF-α, IL-1β, and IL-6 in BALF. Hydrogen gas also alleviated histopathological changes and cell apoptosis. Moreover, Nrf2 and HO-1 expressions were significantly activated and caspase-3 expression was inhibited. These results demonstrate that hydrogen gas inhalation attenuates seawater instillation-induced acute lung injury in rabbits and that the protective effects observed may be related to the activation of the Nrf2 pathway.

  20. Cytoprotective effect exerted by geraniin in HepG2 cells is through microRNA mediated regulation of BACH-1 and HO-1.

    Science.gov (United States)

    Aayadi, Hoda; Mittal, Smriti P K; Deshpande, Anjali; Gore, Makarand; Ghaskadbi, Saroj S

    2017-11-01

    Geraniin, a hydrolysable tannin, used in traditional medicine in Southeast Asia, is known to exhibit various biological activities. As an antioxidant it is known to up-regulate phase II enzyme Heme oxygenase-1 (HO-1). However its mechanism is not clearly understood. Nuclear factor erythroid-derived 2 related factor 2 (Nrf-2) is transcriptionally up-regulated by Extracellular signal-regulated kinase (ERK) 1/2 and retained in nucleus due to inactivated Glycogen synthase kinase 3 beta (GSK-3β). Geraniin additionally down-regulates expression of microRNA 217 and 377 (miR-217 and miR-377) which target HO-1 mRNA. Expression of BTB and CNC homolog 1 (BACH-1), another regulator of HO-1, is also down-regulated by up-regulating microRNA 98 (miR-98), a negative regulator of BACH-1. Thus, geraniin up-regulates HO-1 expression both through activating its positive regulator Nrf-2 and by down-regulating its negative regulator BACH-1. Up-regulation of HO-1 also confers protection to HepG2 cells from tertiary butyl hydroperoxide (TBH) induced cytotoxicity. [BMB Reports 2017; 50(11): 560-565].

  1. Evaluation of potential antioxidant and anti-inflammatory effects of Antrodia cinnamomea powder and the underlying molecular mechanisms via Nrf2- and NF-κB-dominated pathways in broiler chickens.

    Science.gov (United States)

    Lee, M T; Lin, W C; Wang, S Y; Lin, L J; Yu, B; Lee, T T

    2018-04-17

    Antrodia cinnamomea, a precious and unique medical fungus existing exclusively in Taiwan, exhibits antioxidant and immunomodulatory properties. This study was conducted to evaluate the beneficial effects of A. cinnamomea powder (ACP) and to further illuminate its underlying antioxidant and immunomodulation molecular mechanisms in broilers. The functional compounds of ACP-crude triterpenoids, crude polysaccharides, and total phenolic content-were assayed, respectively. Two-hundred-forty one-day-old broilers (Ross 308) were assigned to 4 treatment groups receiving dietary supplementation with ACP at 0, 0.1, 0.2, and 0.4% for 35 days. Each group had 4 replicate pens, with 15 birds per pen. During 1 to 21- and 22 to 35-day periods, chickens on ACP-supplemented diet demonstrated increased body weight gain, compared to those on the control diet, resulting in increased weight gain throughout the entire experimental period with an increased tendency in feed consumption yet no significant difference in FCR. Blood antioxidant potentiality, superoxide dismutase (SOD), increased in birds fed the supplemented diet at both 21 and 35 d, accompanied by higher catalase (CAT) activity at 21 days. In vivo peripheral blood mononuclear cells (PBMC) exposed to lipopolysaccharide (LPS) and 2,2΄-Azobis(2-amidinopropane) dihydrochloride (AAPH) capability showed that the diminished cell viability caused by both challenge factors was improved in ACP-supplemented groups. Antioxidant genes dominated by Nrf2 genes, such as HO-1 and GCLC, were up-regulated in 35-day-old birds. Inflammatory-related genes, such as IL-1β and IL-6, ruled mainly by NF-κB, were rather down-regulated by 0.2% ACP addition at 21 and 35 days. Protein expression of Nrf2 and NF-κB in the liver supported the mRNA results, demonstrating that all ACP-supplemented groups showed significantly higher Nrf2 expression, whereas the NF-κB was inhibited. In conclusion, preferable microbial balance may putatively indicate the

  2. Proteasome inhibition induces both antioxidant and hb f responses in sickle cell disease via the nrf2 pathway.

    Science.gov (United States)

    Pullarkat, Vinod; Meng, Zhuo; Tahara, Stanley M; Johnson, Cage S; Kalra, Vijay K

    2014-01-01

    Oxidant stress is implicated in the manifestations of sickle cell disease including hemolysis and vascular occlusion. Strategies to induce antioxidant response as well as Hb F (α2γ2) have the potential to ameliorate the severity of sickle cell disease. Nuclear factor (erythroid-derived 2)-like 2 (NFE2L2 or Nrf2) is a transcription factor that regulates antioxidant enzymes as well as γ-globin transcription. The Nrf2 in the cytoplasm is bound to its adapter protein Keap-1 that targets Nrf2 for proteasomal degradation, thereby preventing its nuclear translocation. We examined whether inhibiting the 26S proteasome using the clinically applicable proteasome inhibitors bortezomib and MLN 9708 would promote nuclear translocation of Nrf2, and thereby induce an antioxidant response and as well as Hb F in sickle cell disease. Proteasome inhibitors induced reactive oxygen species (ROS) and thereby increased Nrf2-dependent antioxidant enzyme transcripts, elevated cellular glutathione (GSH) levels and γ-globin transcripts as well as Hb F levels in the K562 cell line and also in erythroid burst forming units (BFU-E) generated from peripheral blood mononuclear cells of sickle cell disease patients. These responses were abolished by siRNA-mediated knockdown of Nrf2. Proteasome inhibitors, especially newer oral agents such as MLN9708 have the potential to be readily translated to clinical trials in sickle cell disease with the dual end points of antioxidant response and Hb F induction.

  3. Unique effects of zinc protoporphyrin on HO-1 induction and apoptosis.

    Science.gov (United States)

    Yang, G; Nguyen, X; Ou, J; Rekulapelli, P; Stevenson, D K; Dennery, P A

    2001-03-01

    Zinc protoporphyrin (ZnPP), a naturally occurring molecule, is increased in iron deficiency and lead intoxication. ZnPP can also induce heme oxygenase (HO-1), the enzyme it competitively inhibits. In cultured cells (HA-1), ZnPP was the strongest HO-1 inducer of any metalloporphyrin (MP) tested. This was not due to increased oxidative stress, enhanced binding at metal response element, nor increased binding at activator protein-1 (AP-1) or SP-1 sites on HO-1. Only ZnPP, however, increased binding of nuclear proteins to early growth response-1 (Egr-1) protein consensus sequence. Pretreatment of HA-1 with cycloheximide inhibited ZnPP-induced HO-1 messenger RNA (mRNA) by 55%. Incubation with antisense Egr-1 oligomers decreased ZnPP-induced HO-1 expression by 47%. Furthermore, the level of HO-1 mRNA induction by ZnPP was 2-fold less in Egr-1-deficient fibroblasts than in wild-type cells. Because no Egr-1 binding site was previously identified on the HO-1 promoter, HA-1 cells were transfected with HO-1 CAT constructs containing segments of a 12.5-kb enhancer region of HO-1. A 196-bp fragment (RH) located approximately 9.5 kb upstream of the transcription start site mediated HO-1 induction by ZnPP alone. DNase I footprinting analysis further revealed that nuclear proteins bound to a 50-bp sequence in the RH. Within this sequence, a novel 9-bp region with 78% homology to the Egr-1 consensus sequence was identified further suggesting that Egr-1 partially mediates HO-1 induction by ZnPP. Lastly, increased apoptosis and nuclear localization were only seen with ZnPP, suggesting that increased ZnPP in disease states may serve as a cellular signaling mechanism.

  4. Protective Effect of the Fruit Hull of Gleditsia sinensis on LPS-Induced Acute Lung Injury Is Associated with Nrf2 Activation

    Directory of Open Access Journals (Sweden)

    Jun-Young Choi

    2012-01-01

    Full Text Available The fruit hull of Gleditsia sinensis (FGS has been prescribed as a traditional eastern Asian medicinal remedy for the treatment of various respiratory diseases, but the efficacy and underlying mechanisms remain poorly characterized. Here, we explored a potential usage of FGS for the treatment of acute lung injury (ALI, a highly fatal inflammatory lung disease that urgently needs effective therapeutics, and investigated a mechanism for the anti-inflammatory activity of FGS. Pretreatment of C57BL/6 mice with FGS significantly attenuated LPS-induced neutrophilic lung inflammation compared to sham-treated, inflamed mice. Reporter assays, semiquantitative RT-PCR, and Western blot analyses show that while not affecting NF-κB, FGS activated Nrf2 and expressed Nrf2-regulated genes including GCLC, NQO-1, and HO-1 in RAW 264.7 cells. Furthermore, pretreatment of mice with FGS enhanced the expression of GCLC and HO-1 but suppressed that of proinflammatory cytokines in including TNF-α and IL-1β in the inflamed lungs. These results suggest that FGS effectively suppresses neutrophilic lung inflammation, which can be associated with, at least in part, FGS-activating anti-inflammatory factor Nrf2. Our results suggest that FGS can be developed as a therapeutic option for the treatment of ALI.

  5. Itaconate is an anti-inflammatory metabolite that activates Nrf2 via alkylation of KEAP1.

    Science.gov (United States)

    Mills, Evanna L; Ryan, Dylan G; Prag, Hiran A; Dikovskaya, Dina; Menon, Deepthi; Zaslona, Zbigniew; Jedrychowski, Mark P; Costa, Ana S H; Higgins, Maureen; Hams, Emily; Szpyt, John; Runtsch, Marah C; King, Martin S; McGouran, Joanna F; Fischer, Roman; Kessler, Benedikt M; McGettrick, Anne F; Hughes, Mark M; Carroll, Richard G; Booty, Lee M; Knatko, Elena V; Meakin, Paul J; Ashford, Michael L J; Modis, Louise K; Brunori, Gino; Sévin, Daniel C; Fallon, Padraic G; Caldwell, Stuart T; Kunji, Edmund R S; Chouchani, Edward T; Frezza, Christian; Dinkova-Kostova, Albena T; Hartley, Richard C; Murphy, Michael P; O'Neill, Luke A

    2018-03-28

    The endogenous metabolite itaconate has recently emerged as a regulator of macrophage function, but its precise mechanism of action remains poorly understood. Here we show that itaconate is required for the activation of the anti-inflammatory transcription factor Nrf2 (also known as NFE2L2) by lipopolysaccharide in mouse and human macrophages. We find that itaconate directly modifies proteins via alkylation of cysteine residues. Itaconate alkylates cysteine residues 151, 257, 288, 273 and 297 on the protein KEAP1, enabling Nrf2 to increase the expression of downstream genes with anti-oxidant and anti-inflammatory capacities. The activation of Nrf2 is required for the anti-inflammatory action of itaconate. We describe the use of a new cell-permeable itaconate derivative, 4-octyl itaconate, which is protective against lipopolysaccharide-induced lethality in vivo and decreases cytokine production. We show that type I interferons boost the expression of Irg1 (also known as Acod1) and itaconate production. Furthermore, we find that itaconate production limits the type I interferon response, indicating a negative feedback loop that involves interferons and itaconate. Our findings demonstrate that itaconate is a crucial anti-inflammatory metabolite that acts via Nrf2 to limit inflammation and modulate type I interferons.

  6. Activating Nrf-2 signaling depresses unilateral ureteral obstruction-evoked mitochondrial stress-related autophagy, apoptosis and pyroptosis in kidney.

    Directory of Open Access Journals (Sweden)

    Shue Dong Chung

    Full Text Available Exacerbated oxidative stress and inflammation may induce three types of programmed cell death, autophagy, apoptosis and pyroptosis in unilateral ureteral obstruction (UUO kidney. Sulforaphane activating NF-E2-related nuclear factor erythroid-2 (Nrf-2 signaling may ameliorate UUO-induced renal damage. UUO was induced in the left kidney of female Wistar rats. The level of renal blood flow, cortical and medullary oxygen tension and reactive oxygen species (ROS was evaluated. Fibrosis, ED-1 (macrophage/monocyte infiltration, oxidative stress, autophagy, apoptosis and pyroptosis were evaluated by immunohistochemistry and Western blot in UUO kidneys. Effects of sulforaphane, an Nrf-2 activator, on Nrf-2- and mitochondrial stress-related proteins and renal injury were examined. UUO decreased renal blood flow and oxygen tension and increased renal ROS, 3-nitrotyrosine stain, ED-1 infiltration and fibrosis. Enhanced renal tubular Beclin-1 expression started at 4 h UUO and further enhanced at 3d UUO, whereas increased Atg-5-Atg12 and LC3-II expression were found at 3d UUO. Increased renal Bax/Bcl-2 ratio, caspase 3 and PARP fragments, apoptosis formation associated with increased caspase 1 and IL-1β expression for pyroptosis formation were started from 3d UUO. UUO reduced nuclear Nrf-2 translocation, increased cytosolic and inhibitory Nrf-2 expression, increased cytosolic Bax translocation to mitochondrial and enhanced mitochondrial Cytochrome c release into cytosol of the UUO kidneys. Sulforaphane significantly increased nuclear Nrf-2 translocation and decreased mitochondrial Bax translocation and Cytochrome c release into cytosol resulting in decreased renal injury. In conclusion, sulforaphane via activating Nrf-2 signaling preserved mitochondrial function and suppressed UUO-induced renal oxidative stress, inflammation, fibrosis, autophagy, apoptosis and pyroptosis.

  7. The Crosstalk between Nrf2 and TGF-β1 in the Epithelial-Mesenchymal Transition of Pancreatic Duct Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Sarah Arfmann-Knübel

    Full Text Available Nrf2 and TGF-β1 both affect tumorigenesis in a dual fashion, either by preventing carcinogen induced carcinogenesis and suppressing tumor growth, respectively, or by conferring cytoprotection and invasiveness to tumor cells during malignant transformation. Given the involvement of Nrf2 and TGF-β1 in the adaptation of epithelial cells to persistent inflammatory stress, e.g. of the pancreatic duct epithelium during chronic pancreatitis, a crosstalk between Nrf2 and TGF-β1 can be envisaged. By using premalignant human pancreatic duct cells (HPDE and the pancreatic ductal adenocarcinoma cell line Colo357, we could show that Nrf2 and TGF-β1 independently but additively conferred an invasive phenotype to HPDE cells, whereas acting synergistically in Colo357 cells. This was accompanied by differential regulation of EMT markers like vimentin, Slug, L1CAM and E-cadherin. Nrf2 activation suppressed E-cadherin expression through an as yet unidentified ARE related site in the E-cadherin promoter, attenuated TGF-β1 induced Smad2/3-activity and enhanced JNK-signaling. In Colo357 cells, TGF-β1 itself was capable of inducing Nrf2 whereas in HPDE cells TGF-β1 per-se did not affect Nrf2 activity, but enhanced Nrf2 induction by tBHQ. In Colo357, but not in HPDE cells, the effects of TGF-β1 on invasion were sensitive to Nrf2 knock-down. In both cell lines, E-cadherin re-expression inhibited the proinvasive effect of Nrf2. Thus, the increased invasion of both cell lines relates to the Nrf2-dependent downregulation of E-cadherin expression. In line, immunohistochemistry analysis of human pancreatic intraepithelial neoplasias in pancreatic tissues from chronic pancreatitis patients revealed strong Nrf2 activity already in premalignant epithelial duct cells, accompanied by partial loss of E-cadherin expression. Our findings indicate that Nrf2 and TGF-β1 both contribute to malignant transformation through distinct EMT related mechanisms accounting for an

  8. Propolis reversed cigarette smoke-induced emphysema through macrophage alternative activation independent of Nrf2.

    Science.gov (United States)

    Barroso, Marina Valente; Cattani-Cavalieri, Isabella; de Brito-Gitirana, Lycia; Fautrel, Alain; Lagente, Vincent; Schmidt, Martina; Porto, Luís Cristóvão; Romana-Souza, Bruna; Valença, Samuel Santos; Lanzetti, Manuella

    2017-10-15

    Chronic obstructive pulmonary disease (COPD) is an incurable and progressive disease. Emphysema is the principal manifestation of COPD, and the main cause of this condition is cigarette smoke (CS). Natural products have shown antioxidant and anti-inflammatory properties that can prevent acute lung inflammation and emphysema, but there are few reports in the literature regarding therapeutic approaches to emphysema. We hypothesized that supplementation with natural extracts would repair lung damage in emphysema caused by CS exposure. Mice were exposed to 60days of CS and then treated or not with three different natural extracts (mate tea, grape and propolis) orally for additional 60days. Histological analysis revealed significant improvements in lung histoarchitecture, with recovery of alveolar spaces in all groups treated with natural extracts. Propolis was also able to recovery alveolar septa and elastic fibers. Propolis also increased MMP-2 and decreased MMP-12 expression, favoring the process of tissue repair. Additionally, propolis recruited leukocytes, including macrophages, without ROS release. These findings led us to investigate the profile of these macrophages, and we showed that propolis could promote macrophage alternative activation, thus increasing the number of arginase-positive cells and IL-10 levels and favoring an anti-inflammatory microenvironment. We further investigated the participation of Nrf2 in lung repair, but no Nrf2 translocation to the nucleus was observed in lung cells. Proteins and enzymes related to Nrf2 were not altered, other than NQO1, which seemed to be activated by propolis in a Nrf2-independent manner. Finally, propolis downregulated IGF1 expression. In conclusion, propolis promoted lung repair in a mouse emphysema model via macrophage polarization from M1 to M2 in parallel to the downregulation of IGF1 expression in a Nrf2-independent manner. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Fenofibrate activates Nrf2 through p62-dependent Keap1 degradation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Su [Severance Biomedical Science Institute (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kang, Dong Hoon [Department of Life Science and Ewha Research Center for Systems Biology (Korea, Republic of); The Research Center for Cell Homeostasis, Ewha Womans University, Seoul 127-750 (Korea, Republic of); Lee, Da Hyun [Severance Biomedical Science Institute (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Bae, Soo Han, E-mail: soohanbae@yuhs.ac [Severance Biomedical Science Institute (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of)

    2015-09-25

    Peroxisome proliferator-activated receptor α (PPARα) activates the β-oxidation of fatty acids in the liver. Fenofibrate is a potent agonist of PPARα and is used in the treatment of hyperlipidemia. Fenofibrate treatment often induces the production of intracellular reactive oxygen species (ROS), leading to cell death. The nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway is an essential component of the defense mechanism against oxidative stress. However, the molecular mechanism underlying the regulation of the Nrf2-Keap1 pathway in fenofibrate-induced cell death is not known. In this study, we demonstrated that fenofibrate induces Keap1 degradation and Nrf2 activation. This fenofibrate-mediated Keap1 degradation is partly dependent on autophagy. Furthermore, fenofibrate-induced Keap1 degradation followed by Nrf2 activation is mainly mediated by p62, which functions as an adaptor protein in the autophagic pathway. Consistent with these findings, ablation of p62 increased fenofibrate-mediated apoptotic cell death associated with ROS accumulation. These results strongly suggest that p62 plays a crucial role in preventing fenofibrate-induced cell death. - Highlights: • Fenofibrate induces cell death by increasing ROS production. • The underlying defense mechanism against this effect is unknown. • Fenofibrate induces autophagy-dependent Keap1 degradation and Nrf2 activation. • This process is p62-dependent; lack of p62 enhanced fenofibrate-mediated apoptosis. • p62 plays a crucial role in preventing fenofibrate-induced cell death.

  10. Repeated Nrf2 stimulation using sulforaphane protects fibroblasts from ionizing radiation.

    Science.gov (United States)

    Mathew, Sherin T; Bergström, Petra; Hammarsten, Ola

    2014-05-01

    Most of the cytotoxicity induced by ionizing radiation is mediated by radical-induced DNA double-strand breaks. Cellular protection from free radicals can be stimulated several fold by sulforaphane-mediated activation of the transcription factor Nrf2 that regulates more than 50 genes involved in the detoxification of reactive substances and radicals. Here, we report that repeated sulforaphane treatment increases radioresistance in primary human skin fibroblasts. Cells were either treated with sulforaphane for four hours once or with four-hour treatments repeatedly for three consecutive days prior to radiation exposure. Fibroblasts exposed to repeated-sulforaphane treatment showed a more pronounced dose-dependent induction of Nrf2-regulated mRNA and reduced amount of radiation-induced free radicals compared with cells treated once with sulforaphane. In addition, radiation- induced DNA double-strand breaks measured by gamma-H2AX foci were attenuated following repeated sulforaphane treatment. As a result, cellular protection from ionizing radiation measured by the 5-ethynyl-2'-deoxyuridine (EdU) assay was increased, specifically in cells exposed to repeated sulforaphane treatment. Sulforaphane treatment was unable to protect Nrf2 knockout mouse embryonic fibroblasts, indicating that the sulforaphane-induced radioprotection was Nrf2-dependent. Moreover, radioprotection by repeated sulforaphane treatment was dose-dependent with an optimal effect at 10 uM, whereas both lower and higher concentrations resulted in lower levels of radioprotection. Our data indicate that the Nrf2 system can be trained to provide further protection from radical damage. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Respiratory syncytial virus infection down-regulates antioxidant enzyme expression by triggering deacetylation-proteasomal degradation of Nrf2.

    Science.gov (United States)

    Komaravelli, Narayana; Tian, Bing; Ivanciuc, Teodora; Mautemps, Nicholas; Brasier, Allan R; Garofalo, Roberto P; Casola, Antonella

    2015-11-01

    Respiratory syncytial virus (RSV) is the most important cause of viral acute respiratory tract infections and hospitalizations in children, for which no vaccine or treatment is available. RSV infection in cells, mice, and children leads to rapid generation of reactive oxygen species, which are associated with oxidative stress and lung damage, due to a significant decrease in the expression of airway antioxidant enzymes (AOEs). Oxidative stress plays an important role in the pathogenesis of RSV-induced lung disease, as antioxidants ameliorate clinical disease and inflammation in vivo. The aim of this study is to investigate the unknown mechanism(s) of virus-induced inhibition of AOE expression. RSV infection is shown to induce a progressive reduction in nuclear and total cellular levels of the transcription factor NF-E2-related factor 2 (Nrf2), resulting in decreased binding to endogenous AOE gene promoters and decreased AOE expression. RSV induces Nrf2 deacetylation and degradation via the proteasome pathway in vitro and in vivo. Histone deacetylase and proteasome inhibitors block Nrf2 degradation and increase Nrf2 binding to AOE endogenous promoters, resulting in increased AOE expression. Known inducers of Nrf2 are able to increase Nrf2 activation and subsequent AOE expression during RSV infection in vitro and in vivo, with significant amelioration of oxidative stress. This is the first study to investigate the mechanism(s) of virus-induced inhibition of AOE expression. RSV-induced inhibition of Nrf2 activation, due to deacetylation and proteasomal degradation, could be targeted for therapeutic intervention aimed to increase airway antioxidant capacity during infection. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. PCB 126 toxicity is modulated by cross-talk between caveolae and Nrf2 signaling.

    Science.gov (United States)

    Petriello, Michael C; Han, Sung Gu; Newsome, Bradley J; Hennig, Bernhard

    2014-06-01

    Environmental toxicants such as polychlorinated biphenyls (PCBs) have been implicated in the promotion of multiple inflammatory disorders including cardiovascular disease, but information regarding mechanisms of toxicity and cross-talk between relevant cell signaling pathways is lacking. To examine the hypothesis that cross-talk between membrane domains called caveolae and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathways alters PCB-induced inflammation, caveolin-1 was silenced in vascular endothelial cells, resulting in a decreased PCB-induced inflammatory response. Cav-1 silencing (siRNA treatment) also increased levels of Nrf2-ARE transcriptional binding, resulting in higher mRNA levels of the antioxidant genes glutathione s-transferase and NADPH dehydrogenase quinone-1 in both vehicle and PCB-treated systems. Along with this upregulated antioxidant response, Cav-1 siRNA treated cells exhibited decreased mRNA levels of the Nrf2 inhibitory protein Keap1 in both vehicle and PCB-treated samples. Silencing Cav-1 also decreased protein levels of Nrf2 inhibitory proteins Keap1 and Fyn kinase, especially in PCB-treated cells. Further, endothelial cells from wildtype and Cav-1-/- mice were isolated and treated with PCB to better elucidate the role of functional caveolae in PCB-induced endothelial inflammation. Cav-1-/- endothelial cells were protected from PCB-induced cellular dysfunction as evidenced by decreased vascular cell adhesion molecule (VCAM-1) protein induction. Compared to wildtype cells, Cav-1-/- endothelial cells also allowed for a more effective antioxidant response, as observed by higher levels of the antioxidant genes. These data demonstrate novel cross-talk mechanisms between Cav-1 and Nrf2 and implicate the reduction of Cav-1 as a protective mechanism for PCB-induced cellular dysfunction and inflammation. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Transcription factor Nrf2 mediates an adaptive response to sulforaphane that protects fibroblasts in vitro against the cytotoxic effects of electrophiles, peroxides and redox-cycling agents

    International Nuclear Information System (INIS)

    Higgins, Larry G.; Kelleher, Michael O.; Eggleston, Ian M.; Itoh, Ken; Yamamoto, Masayuki; Hayes, John D.

    2009-01-01

    Sulforaphane can stimulate cellular adaptation to redox stressors through transcription factor Nrf2. Using mouse embryonic fibroblasts (MEFs) as a model, we show herein that the normal homeostatic level of glutathione in Nrf2 -/- MEFs was only 20% of that in their wild-type counterparts. Furthermore, the rate of glutathione synthesis following its acute depletion upon treatment with 3 μmol/l sulforaphane was very substantially lower in Nrf2 -/- MEFs than in wild-type cells, and the rebound leading to a ∼ 1.9-fold increase in glutathione that occurred 12-24 h after Nrf2 +/+ MEFs were treated with sulforaphane was not observed in Nrf2 -/- fibroblasts. Wild-type MEFs that had been pre-treated for 24 h with 3 μmol/l sulforaphane exhibited between 1.4- and 3.2-fold resistance against thiol-reactive electrophiles, including isothiocyanates, α,β-unsaturated carbonyl compounds (e.g. acrolein), aryl halides and alkene epoxides. Pre-treatment of Nrf2 +/+ MEFs with sulforaphane also protected against hydroperoxides (e.g. cumene hydroperoxide, CuOOH), free radical-generating compounds (e.g. menadione), and genotoxic electrophiles (e.g. chlorambucil). By contrast, Nrf2 -/- MEFs were typically ∼ 50% less tolerant of these agents than wild-type fibroblasts, and sulforaphane pre-treatment did not protect the mutant cells against xenobiotics. To test whether Nrf2-mediated up-regulation of glutathione represents the major cytoprotective mechanism stimulated by sulforaphane, 5 μmol/l buthionine sulfoximine (BSO) was used to inhibit glutathione synthesis. In Nrf2 +/+ MEFs pre-treated with sulforaphane, BSO diminished intrinsic resistance and abolished inducible resistance to acrolein, CuOOH and chlorambucil, but not menadione. Thus Nrf2-dependent up-regulation of GSH is the principal mechanism by which sulforaphane pre-treatment induced resistance to acrolein, CuOOH and chlorambucil, but not menadione.

  14. Extratumoral Heme Oxygenase-1 (HO-1 Expressing Macrophages Likely Promote Primary and Metastatic Prostate Tumor Growth.

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    Sofia Halin Bergström

    Full Text Available Aggressive tumors induce tumor-supporting changes in the benign parts of the prostate. One factor that has increased expression outside prostate tumors is hemoxygenase-1 (HO-1. To investigate HO-1 expression in more detail, we analyzed samples of tumor tissue and peritumoral normal prostate tissue from rats carrying cancers with different metastatic capacity, and human prostate cancer tissue samples from primary tumors and bone metastases. In rat prostate tumor samples, immunohistochemistry and quantitative RT-PCR showed that the main site of HO-1 synthesis was HO-1+ macrophages that accumulated in the tumor-bearing organ, and at the tumor-invasive front. Small metastatic tumors were considerably more effective in attracting HO-1+ macrophages than larger non-metastatic ones. In clinical samples, accumulation of HO-1+ macrophages was seen at the tumor invasive front, almost exclusively in high-grade tumors, and it correlated with the presence of bone metastases. HO-1+ macrophages, located at the tumor invasive front, were more abundant in bone metastases than in primary tumors. HO-1 expression in bone metastases was variable, and positively correlated with the expression of macrophage markers but negatively correlated with androgen receptor expression, suggesting that elevated HO-1 could be a marker for a subgroup of bone metastases. Together with another recent observation showing that selective knockout of HO-1 in macrophages reduced prostate tumor growth and metastatic capacity in animals, the results of this study suggest that extratumoral HO-1+ macrophages may have an important role in prostate cancer.

  15. SPBP Is a Sulforaphane Induced Transcriptional Coactivator of NRF2 Regulating Expression of the Autophagy Receptor p62/SQSTM1

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    Darvekar, Sagar Ramesh; Elvenes, Julianne; Brenne, Hanne Britt; Johansen, Terje; Sjøttem, Eva

    2014-01-01

    Organisms exposed to oxidative stress respond by orchestrating a stress response to prevent further damage. Intracellular levels of antioxidant agents increase, and damaged components are removed by autophagy induction. The KEAP1-NRF2 signaling pathway is the main pathway responsible for cell defense against oxidative stress and for maintaining the cellular redox balance at physiological levels. Sulforaphane, an isothiocyanate derived from cruciferous vegetables, is a potent inducer of KEAP1-NRF2 signaling and antioxidant response element driven gene expression. In this study, we show that sulforaphane enhances the expression of the transcriptional coregulator SPBP. The expression curve peaks 6–8 hours post stimulation, and parallels the sulforaphane-induced expression of NRF2 and the autophagy receptor protein p62/SQSTM1. Reporter gene assays show that SPBP stimulates the expression of p62/SQSTM1 via ARE elements in the promoter region, and siRNA mediated knock down of SPBP significantly decreases the expression of p62/SQSTM1 and the formation of p62/SQSTM1 bodies in HeLa cells. Furthermore, SPBP siRNA reduces the sulforaphane induced expression of NRF2, and the expression of the autophagy marker protein LC3B. Both these proteins contain ARE-like elements in their promoter regions. Over-expressed SPBP and NRF2 acts synergistically on the p62/SQSTM1 promoter and colocalize in nuclear speckles in HeLa cells. Collectively, these results suggest that SPBP is a coactivator of NRF2, and hence may be important for securing enhanced and sustained expression of NRF2 induced genes such as proteins involved in selective autophagy. PMID:24416372

  16. SPBP is a sulforaphane induced transcriptional coactivator of NRF2 regulating expression of the autophagy receptor p62/SQSTM1.

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    Sagar Ramesh Darvekar

    Full Text Available Organisms exposed to oxidative stress respond by orchestrating a stress response to prevent further damage. Intracellular levels of antioxidant agents increase, and damaged components are removed by autophagy induction. The KEAP1-NRF2 signaling pathway is the main pathway responsible for cell defense against oxidative stress and for maintaining the cellular redox balance at physiological levels. Sulforaphane, an isothiocyanate derived from cruciferous vegetables, is a potent inducer of KEAP1-NRF2 signaling and antioxidant response element driven gene expression. In this study, we show that sulforaphane enhances the expression of the transcriptional coregulator SPBP. The expression curve peaks 6-8 hours post stimulation, and parallels the sulforaphane-induced expression of NRF2 and the autophagy receptor protein p62/SQSTM1. Reporter gene assays show that SPBP stimulates the expression of p62/SQSTM1 via ARE elements in the promoter region, and siRNA mediated knock down of SPBP significantly decreases the expression of p62/SQSTM1 and the formation of p62/SQSTM1 bodies in HeLa cells. Furthermore, SPBP siRNA reduces the sulforaphane induced expression of NRF2, and the expression of the autophagy marker protein LC3B. Both these proteins contain ARE-like elements in their promoter regions. Over-expressed SPBP and NRF2 acts synergistically on the p62/SQSTM1 promoter and colocalize in nuclear speckles in HeLa cells. Collectively, these results suggest that SPBP is a coactivator of NRF2, and hence may be important for securing enhanced and sustained expression of NRF2 induced genes such as proteins involved in selective autophagy.

  17. Nrf2/Keap1 system regulates vascular smooth muscle cell apoptosis for vascular homeostasis: role in neointimal formation after vascular injury.

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    Ashino, Takashi; Yamamoto, Masayuki; Numazawa, Satoshi

    2016-05-20

    Abnormal increases in vascular smooth muscle cells (VSMCs) in the intimal region after a vascular injury is a key event in developing neointimal hyperplasia. To maintain vascular function, proliferation and apoptosis of VSMCs is tightly controlled during vascular remodeling. NF-E2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1) system, a key component of the oxidative stress response that acts in maintaining homeostasis, plays an important role in neointimal hyperplasia after a vascular injury; however, the role of Nrf2/Keap1 in VSMC apoptosis has not been clarified. Here we report that 14 days after arterial injury in mice, TUNEL-positive VSMCs are detected in both the neointimal and medial layers. These layers contain cells expressing high levels of Nrf2 but low Keap1 expression. In VSMCs, Keap1 depletion induces features of apoptosis, such as positive TUNEL staining and annexin V binding. These changes are associated with an increased expression of nuclear Nrf2. Simultaneous Nrf2 depletion inhibits Keap1 depletion-induced apoptosis. At 14 days after the vascular injury, Nrf2-deficient mice demonstrated fewer TUNEL-positive cells and increased neointimal formation in the neointimal and medial areas. The results suggest that the Nrf2/Keap1 system regulates VSMC apoptosis during neointimal formation, thereby inhibiting neointimal hyperplasia after a vascular injury.

  18. Astaxanthin Activates Nuclear Factor Erythroid-Related Factor 2 and the Antioxidant Responsive Element (Nrf2-ARE Pathway in the Brain after Subarachnoid Hemorrhage in Rats and Attenuates Early Brain Injury

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    Qi Wu

    2014-12-01

    Full Text Available Astaxanthin (ATX has been proven to ameliorate early brain injury (EBI after experimental subarachnoid hemorrhage (SAH by modulating cerebral oxidative stress. This study was performed to assess the effect of ATX on the Nrf2-ARE pathway and to explore the underlying molecular mechanisms of antioxidant properties of ATX in EBI after SAH. A total of 96 male SD rats were randomly divided into four groups. Autologous blood was injected into the prechiasmatic cistern of the rat to induce an experimental SAH model. Rats in each group were sacrificed at 24 h after SAH. Expressions of Nrf2 and heme oxygenase-1 (HO-1 were measured by Western blot and immunohistochemistry analysis. The mRNA levels of HO-1, NAD (P H: quinone oxidoreductase 1 (NQO-1, and glutathione S-transferase-α1 (GST-α1 were determined by real-time polymerase chain reaction (PCR. It was observed that administration of ATX post-SAH could up-regulate the cortical expression of these agents, mediated in the Nrf2-ARE pathway at both pretranscriptional and posttranscriptional levels. Meanwhile, oxidative damage was reduced. Furthermore, ATX treatment significantly attenuated brain edema, blood–brain barrier (BBB disruption, cellular apoptosis, and neurological dysfunction in SAH models. This study demonstrated that ATX treatment alleviated EBI in SAH model, possibly through activating the Nrf2-ARE pathway by inducing antioxidant and detoxifying enzymes.

  19. Sulforaphane is a Nrf2-independent inhibitor of mitochondrial fission

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    Gary B. O'Mealey

    2017-04-01

    Full Text Available The KEAP1-Nrf2-ARE antioxidant system is a principal means by which cells respond to oxidative and xenobiotic stresses. Sulforaphane (SFN, an electrophilic isothiocyanate derived from cruciferous vegetables, activates the KEAP1-Nrf2-ARE pathway and has become a molecule-of-interest in the treatment of diseases in which chronic oxidative stress plays a major etiological role. We demonstrate here that the mitochondria of cultured, human retinal pigment epithelial (RPE-1 cells treated with SFN undergo hyperfusion that is independent of both Nrf2 and its cytoplasmic inhibitor KEAP1. Mitochondrial fusion has been reported to be cytoprotective by inhibiting pore formation in mitochondria during apoptosis, and consistent with this, we show Nrf2-independent, cytoprotection of SFN-treated cells exposed to the apoptosis-inducer, staurosporine. Mechanistically, SFN mitigates the recruitment and/or retention of the soluble fission factor Drp1 to mitochondria and to peroxisomes but does not affect overall Drp1 abundance. These data demonstrate that the beneficial properties of SFN extend beyond activation of the KEAP1-Nrf2-ARE system and warrant further interrogation given the current use of this agent in multiple clinical trials.

  20. Contribution of Nrf2 to Atherogenic Phenotype Switching of Coronary Arterial Smooth Muscle Cells Lacking CD38 Gene

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    Ming Xu

    2015-08-01

    Full Text Available Background/Aims: Recent studies have indicated that CD38 gene deficiency results in dedifferentiation or transdifferentiation of arterial smooth muscle cells upon atherogenic stimulations. However, the molecular mechanisms mediating this vascular smooth muscle (SMC phenotypic switching remain unknown. Methods & Results: In the present study, we first characterized the phenotypic change in the primary cultures of coronary arterial myocytes (CAMs from CD38-/- mice. It was shown that CD38 deficiency decreased the expression of contractile marker calponin, SM22α and α-SMA but increased the expression of SMC dedifferentiation marker, vimentin, which was accompanied by enhanced cell proliferation. This phenotypic change in CD38-/- CAMs was enhanced by 7-ketocholesterol (7-Ket, an atherogenic stimulus. We further found that the CD38 deficiency decreased the expression and activity of nuclear factor E2-related factor 2 (Nrf2, a basic leucine zipper (bZIP transcription factor sensitive to redox regulation. Similar to CD38 deletion, Nrf2 gene silencing increased CAM dedifferentiation upon 7-Ket stimulation. In contrast, the overexpression of Nrf2 gene abolished 7-Ket-induced dedifferentiation in CD38-/- CAMs. Given the sensitivity of Nrf2 to oxidative stress, we determined the role of redox signaling in the regulation of Nrf2 expression and activity associated with CD38 effect in CAM phenotype changes. It was demonstrated that in CD38-/- CAMs, 7-Ket failed to stimulate the production of O2-., while in CD38+/+ CAMs 7-Ket induced marked O2-. production and enhancement of Nrf2 activity, which was substantially attenuated by NOX4 gene silencing. Finally, we demonstrated that 7-Ket-induced and NOX4-dependent O2-. production was inhibited by 8-Br-cADPR, an antagonist of cADPR or NED-19, an antagonist of NAADP as product of CD38 ADP-ribosylcyclase, which significantly inhibited the level of cytosolic Ca2+ and the activation of Nrf2 under 7-Ket. Conclusion

  1. HO-1 Upregulation Attenuates Adipocyte Dysfunction, Obesity, and Isoprostane Levels in Mice Fed High Fructose Diets

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    Zeid Khitan

    2014-01-01

    Full Text Available Background. Fructose metabolism is an unregulated metabolic pathway and excessive fructose consumption is known to activate ROS. HO-1 is a potent antioxidant gene that plays a key role in decreasing ROS and isoprostanes. We examined whether the fructose-mediated increase in adipocyte dysfunction involves an increase in isoprostanes and that pharmacological induction of HO-1 would decrease both isoprostane levels and adipogenesis. Methods and Results. We examined the effect of fructose, on adipogenesis in human MSCs in the presence and absence of CoPP, an inducer of HO-1. Fructose increased adipogenesis and the number of large lipid droplets while decreasing the number of small lipid droplets (P<0.05. Levels of heme and isoprostane in fructose treated MSC-derived adipocytes were increased. CoPP reversed these effects and markedly increased HO-1 and the Wnt signaling pathway. The high fructose diet increased heme levels in adipose tissue and increased circulating isoprostane levels (P<0.05 versus control. Fructose diets decreased HO-1 and adiponectin levels in adipose tissue. Induction of HO-1 by CoPP decreased isoprostane synthesis (P<0.05 versus fructose. Conclusion. Fructose treatment resulted in increased isoprostane production and adipocyte dysfunction, which was reversed by the increased expression of HO-1.

  2. Nrf2 Regulates the Risk of a Diesel Exhaust Inhalation-Induced Immune Response during Bleomycin Lung Injury and Fibrosis in Mice.

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    Li, Ying-Ji; Shimizu, Takako; Shinkai, Yusuke; Hirata, Yukiyo; Inagaki, Hirofumi; Takeda, Ken; Azuma, Arata; Yamamoto, Masayuki; Kawada, Tomoyuki

    2017-03-17

    The present study investigated the effects of diesel exhaust (DE) on an experimental model of bleomycin (BLM)-induced lung injury and fibrosis in mice. BLM was intravenously administered to both Nrf2 +/+ and Nrf2 -/- C57BL/6J mice on day 0. The mice were exposed to DE for 56 days from 28 days before the BLM injection to 28 days after the BLM injection. Inhalation of DE induced significant inhibition of airway clearance function and the proinflammatory cytokine secretion in macrophages, an increase in neutrophils, and severe lung inflammatory injury, which were greater in Nrf2 -/- mice than in Nrf2 +/+ mice. In contrast, inhalation of DE was observed to induce a greater increase of hydroxyproline content in the lung tissues and significantly higher pulmonary antioxidant enzyme mRNA expression in the Nrf2 +/+ mice than in Nrf2 -/- mice. DE is an important risk factor, and Nrf2 regulates the risk of a DE inhalation induced immune response during BLM lung injury and fibrosis in mice.

  3. The Transcription Factor Nrf2 Protects Angiogenic Capacity of Endothelial Colony-Forming Cells in High-Oxygen Radical Stress Conditions

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    Hendrik Gremmels

    2017-01-01

    Full Text Available Background. Endothelial colony forming cells (ECFCs have shown a promise in tissue engineering of vascular constructs, where they act as endothelial progenitor cells. After implantation, ECFCs are likely to be subjected to elevated reactive oxygen species (ROS. The transcription factor Nrf2 regulates the expression of antioxidant enzymes in response to ROS. Methods. Stable knockdown of Nrf2 and Keap1 was achieved by transduction with lentiviral shRNAs; activation of Nrf2 was induced by incubation with sulforaphane (SFN. Expression of Nrf2 target genes was assessed by qPCR, oxidative stress was assessed using CM-DCFDA, and angiogenesis was quantified by scratch-wound and tubule-formation assays. Results. Nrf2 knockdown led to a reduction of antioxidant gene expression and increased ROS. Angiogenesis was disturbed after Nrf2 knockdown even in the absence of ROS. Conversely, angiogenesis was preserved in high ROS conditions after knockdown of Keap1. Preincubation of ECFCs with SFN reduced intracellular ROS in the presence of H2O2 and preserved scratch-wound closure and tubule-formation. Conclusion. The results of this study indicate that Nrf2 plays an important role in the angiogenic capacity of ECFCs, particularly under conditions of increased oxidative stress. Pretreatment of ECFCs with SFN prior to implantation may be a protective strategy for tissue-engineered constructs or cell therapies.

  4. Prolonged fasting activates Nrf2 in post-weaned elephant seals.

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    Vázquez-Medina, José Pablo; Soñanez-Organis, José G; Rodriguez, Ruben; Viscarra, Jose A; Nishiyama, Akira; Crocker, Daniel E; Ortiz, Rudy M

    2013-08-01

    Elephant seals naturally experience prolonged periods of absolute food and water deprivation (fasting). In humans, rats and mice, prolonged food deprivation activates the renin-angiotensin system (RAS) and increases oxidative damage. In elephant seals, prolonged fasting activates RAS without increasing oxidative damage likely due to an increase in antioxidant defenses. The mechanism leading to the upregulation of antioxidant defenses during prolonged fasting remains elusive. Therefore, we investigated whether prolonged fasting activates the redox-sensitive transcription factor Nrf2, which controls the expression of antioxidant genes, and if such activation is potentially mediated by systemic increases in RAS. Blood and skeletal muscle samples were collected from seals fasting for 1, 3, 5 and 7 weeks. Nrf2 activity and nuclear content increased by 76% and 167% at week 7. Plasma angiotensin II (Ang II) and transforming growth factor β (TGF-β) were 5000% and 250% higher at week 7 than at week 1. Phosphorylation of Smad2, an effector of Ang II and TGF signaling, increased by 120% at week 7 and by 84% in response to intravenously infused Ang II. NADPH oxidase 4 (Nox4) mRNA expression, which is controlled by smad proteins, increased 430% at week 7, while Nox4 protein expression, which can activate Nrf2, was 170% higher at week 7 than at week 1. These results demonstrate that prolonged fasting activates Nrf2 in elephant seals and that RAS stimulation can potentially result in increased Nox4 through Smad phosphorylation. The results also suggest that Nox4 is essential to sustain the hormetic adaptive response to oxidative stress in fasting seals.

  5. Nrf2-dependent gene expressions: a molecular toxicological aspect.

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    Numazawa, Satoshi; Yoshida, Takemi

    2004-05-01

    Although NF-E2 related factor 2 (Nrf2) was found to be a transcriptional regulator that controls an expression of the beta-globin gene, the notion is now widely accepted that this transfactor serves as a master regulator for the gene expression of a battery of proteins acting on anti-oxidative stress and detoxification of electrophiles. The function of Nrf2 that bears transcriptional activation depends solely on its nuclear localization, which is regulated by interaction with the cytosolic anchor protein Keap1 and its own turnover rate. In the present mini-review, we focus on the regulation of Nrf2 function and discuss the physiological and toxicological aspects of this transcriptional factor.

  6. The Dual Role of Nrf2 in Nonalcoholic Fatty Liver Disease: Regulation of Antioxidant Defenses and Hepatic Lipid Metabolism

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    Sílvia S. Chambel

    2015-01-01

    Full Text Available Nonalcoholic fatty liver disease (NAFLD is a progressive liver disease with ever-growing incidence in the industrialized world. It starts with the simple accumulation of lipids in the hepatocyte and can progress to the more severe nonalcoholic steatohepatitis (NASH, which is associated with inflammation, fibrosis, and cirrhosis. There is increasing awareness that reactive oxygen species and electrophiles are implicated in the pathogenesis of NASH. Transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2 is a positive regulator of the expression of a battery of genes involved in the protection against oxidative/electrophilic stress. In rodents, Nrf2 is also known to participate in hepatic fatty acid metabolism, as a negative regulator of genes that promote hepatosteatosis. We review relevant evidence in the literature that these two mechanisms may contribute to the protective role of Nrf2 in the development of hepatic steatosis and in the progression to steatohepatitis, particularly in young animals. We propose that age may be a key to explain contradictory findings in the literature. In summary, Nrf2 mediates the crosstalk between lipid metabolism and antioxidant defense mechanisms in experimental models of NAFLD, and the nutritional or pharmacological induction of Nrf2 represents a promising potential new strategy for its prevention and treatment.

  7. Targeted deletion of Nrf2 reduces urethane-induced lung tumor development in mice.

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    Alison K Bauer

    Full Text Available Nrf2 is a key transcription factor that regulates cellular redox and defense responses. However, permanent Nrf2 activation in human lung carcinomas promotes pulmonary malignancy and chemoresistance. We tested the hypothesis that Nrf2 has cell survival properties and lack of Nrf2 suppresses chemically-induced pulmonary neoplasia by treating Nrf2(+/+ and Nrf2(-/- mice with urethane. Airway inflammation and injury were assessed by bronchoalveolar lavage analyses and histopathology, and lung tumors were analyzed by gross and histologic analysis. We used transcriptomics to assess Nrf2-dependent changes in pulmonary gene transcripts at multiple stages of neoplasia. Lung hyperpermeability, cell death and apoptosis, and inflammatory cell infiltration were significantly higher in Nrf2(-/- mice compared to Nrf2(+/+ mice 9 and 11 wk after urethane. Significantly fewer lung adenomas were found in Nrf2(-/- mice than in Nrf2(+/+ mice at 12 and 22 wk. Nrf2 modulated expression of genes involved cell-cell signaling, glutathione metabolism and oxidative stress response, and immune responses during early stage neoplasia. In lung tumors, Nrf2-altered genes had roles in transcriptional regulation of cell cycle and proliferation, carcinogenesis, organismal injury and abnormalities, xenobiotic metabolism, and cell-cell signaling genes. Collectively, Nrf2 deficiency decreased susceptibility to urethane-induced lung tumorigenesis in mice. Cell survival properties of Nrf2 were supported, at least in part, by reduced early death of initiated cells and heightened advantage for tumor cell expansion in Nrf2(+/+ mice relative to Nrf2(-/- mice. Our results were consistent with the concept that Nrf2 over-activation is an adaptive response of cancer conferring resistance to anti-cancer drugs and promoting malignancy.

  8. Silymarin protects against acrylamide-induced neurotoxicity via Nrf2 signalling in PC12 cells.

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    Li, Liang; Sun, Hong-Yang; Liu, Wei; Zhao, Hong-Yu; Shao, Mei-Li

    2017-04-01

    Silymarin (SM) is a well-known antioxidant, anti-inflammatory and anti-cancer compound extracted from the milk thistle. Here, we investigated the protective effect of SM against acrylamide (AA)-induced neurotoxicity, mainly caused by oxidative stress, via activation of the nuclear transcription factor E2-related factor 2 (Nrf2) signalling pathway in PC12 cells. The MTT reduction assay was used to measure cell viability in various drug-treated groups and demonstrated that SM could increase cell viability in AA-treated PC12 cells. We then measured the reactive oxygen species (ROS) levels by the peroxide-sensitive fluorescent probe DCFH-DA and intracellular glutathione (GSH) and malondialdehyde (MDA) levels by absorption spectrophotometry. Our data revealed that SM could reduce ROS and MDA levels and increase GSH levels in AA-induced PC12 cells. To identify a potential mechanism for SM-induced protection, we measured the mRNA and protein expression levels of Nrf2 and its downstream target antioxidants glutathione peroxidase (Gpx), glutamate cysteine ligase catalytic subunit (GCLC) and glutamate cysteine ligase modifier subunit (GCLM) by quantitative real-time PCR and Western blot, respectively. The results suggested that SM could activate Nrf2 signalling and increase the expression of Nrf2, Gpx, GCLC and GCLM in AA-treated PC12 cells. In conclusion, SM can effectively alleviate AA-induced neurotoxicity in PC12 cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. TOP 1 and 2, polysaccharides from Taraxacum officinale, inhibit NFκB-mediated inflammation and accelerate Nrf2-induced antioxidative potential through the modulation of PI3K-Akt signaling pathway in RAW 264.7 cells.

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    Park, Chung Mu; Cho, Chung Won; Song, Young Sun

    2014-04-01

    Anti-inflammatory and anti-oxidative activities of polysaccharides from Taraxacum officinale (TOP 1 and 2) were analyzed in RAW 264.7 cells. First, lipopolysaccharide (LPS) was applied to identify anti-inflammatory activity of TOPs, which reduced expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-α. TOPs treatment inhibited phosphorylation of inflammatory transcription factor, nuclear factor (NF)κB, and its upstream signaling molecule, PI3K/Akt. Second, cytoprotective potential of TOPs against oxidative stress was investigated via heme oxygenase (HO)-1 induction. HO-1, one of phase II enzymes shows antioxidative activity, was potently induced by TOPs treatment, which was in accordance with the nuclear translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2). In addition, TOPs treatment phosphorylated PI3K/Akt with slight activation of c-Jun NH2-terminal kinase (JNK). TOPs-mediated HO-1 induction protected macrophage cells from oxidative stress-induced cell death, which was confirmed by SnPP and CoPP (HO-1 inhibitor and inducer, respectively). Consequently, TOPs potently inhibited NFκB-mediated inflammation and accelerated Nrf2-mediated antioxidative potential through the modulation of PI3K/Akt pathway, which would contribute to their promising strategy for novel anti-inflammatory and anti-oxidative agents. Copyright © 2014. Published by Elsevier Ltd.

  10. Topical application of the synthetic triterpenoid RTA 408 activates Nrf2 and induces cytoprotective genes in rat skin.

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    Reisman, Scott A; Lee, Chun-Yue I; Meyer, Colin J; Proksch, Joel W; Ward, Keith W

    2014-07-01

    RTA 408 is a member of the synthetic oleanane triterpenoid class of compounds known to potently activate the cytoprotective transcription factor Nrf2. Because skin is constantly exposed to external oxidative stress, such as that from ultraviolet radiation, from chemical exposure, during improper wound healing, and throughout the course of cancer radiation therapy, it may benefit from activation of Nrf2. This study was conducted to evaluate the transdermal penetration properties and Nrf2 activation potential of RTA 408 in normal rat skin. RTA 408 (0.1, 1.0, or 3.0%) was applied topically to the shaved skin of male Sprague-Dawley rats twice daily for 4 days and once on Day 5. Topical application of RTA 408 resulted in transdermal penetration, with low but dose-dependent plasma exposure with AUC(0-24 h) values of 3.6, 26.0, and 41.1 h ng/mL for the 0.1, 1.0, and 3.0% doses, respectively. Further, topical application of RTA 408 resulted in increased translocation of Nrf2 to the nucleus, dose-dependent mRNA induction of Nrf2 target genes (e.g. Nqo1, Srxn1, Gclc, and Gclm), and induction of the protein expression of the prototypical Nrf2 target gene Nqo1 and increased total glutathione (GSH) in normal rat skin. Immunohistochemistry demonstrated that increased staining for Nqo1 and total GSH of structures in both the epidermis and dermis was consistent with the full transdermal penetration of RTA 408. Finally, topically administered RTA 408 was well tolerated with no adverse in-life observations and normal skin histology. Thus, the data support the further development of RTA 408 for the potential treatment of skin diseases.

  11. Andrographolide protects against cigarette smoke-induced oxidative lung injury via augmentation of Nrf2 activity

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    Guan, SP; Tee, W; Ng, DSW; Chan, TK; Peh, HY; Ho, WE; Cheng, C; Mak, JC; Wong, WSF

    2013-01-01

    Background and Purpose Cigarette smoke is a major cause for chronic obstructive pulmonary disease (COPD). Andrographolide is an active biomolecule isolated from the plant Andrographis paniculata. Andrographolide has been shown to activate nuclear factor erythroid-2-related factor 2 (Nrf2), a redox-sensitive antioxidant transcription factor. As Nrf2 activity is reduced in COPD, we hypothesize that andrographolide may have therapeutic value for COPD. Experimental Approach Andrographolide was given i.p. to BALB/c mice daily 2 h before 4% cigarette smoke exposure for 1 h over five consecutive days. Bronchoalveolar lavage fluid and lungs were collected for analyses of cytokines, oxidative damage markers and antioxidant activities. BEAS-2B bronchial epithelial cells were exposed to cigarette smoke extract (CSE) and used to study the antioxidant mechanism of action of andrographolide. Key Results Andrographolide suppressed cigarette smoke-induced increases in lavage fluid cell counts; levels of IL-1β, MCP-1, IP-10 and KC; and levels of oxidative biomarkers 8-isoprostane, 8-OHdG and 3-nitrotyrosine in a dose-dependent manner. Andrographolide promoted inductions of glutathione peroxidase (GPx) and glutathione reductase (GR) activities in lungs from cigarette smoke-exposed mice. In BEAS-2B cells, andrographolide markedly increased nuclear Nrf2 accumulation, promoted binding to antioxidant response element (ARE) and total cellular glutathione level in response to CSE. Andrographolide up-regulated ARE-regulated gene targets including glutamate-cysteine ligase catalytic (GCLC) subunit, GCL modifier (GCLM) subunit, GPx, GR and heme oxygenase-1 in BEAS-2B cells in response to CSE. Conclusions Andrographolide possesses antioxidative properties against cigarette smoke-induced lung injury probably via augmentation of Nrf2 activity and may have therapeutic potential for treating COPD. PMID:23146110

  12. Geraniin attenuates LPS-induced acute lung injury via inhibiting NF-κB and activating Nrf2 signaling pathways.

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    Zhu, Guangfa; Xin, Xi; Liu, Yan; Huang, Yan; Li, Keng; Wu, Chunting

    2017-04-04

    Geraniin, a typical ellagitannin isolated from Phyllanthusurinaria Linn, has been reported to have anti-inflammatory effect. The aim of the study is to investigate the therapeutic effects of geraniin on LPS-induced acute lung injury (ALI) in mice. The mice were intranasal adminisration of LPS for 12 h. Geraniin was intra-peritoneal injection 1 h after LPS treatment. The results showed that geraniin significantly attenuated LPS-induced pathological changes in the lung. Geraniin also inhibited LPS-induced macrophages and neutrophils infiltration in the lung. Geraniin significantly attenuated LPS-induced elevation of MPO level. LPS-induced TNF-α, IL-6 and IL-1β production were markedly suppressed by treatment of geraniin. Furthermore, geraniin inhibited NF-κB activation in LPS-induced ALI. In addition, geraniin was found to up-regulate the expression of Nrf2 and HO-1. In conclusion, these data suggested that geraniin had therapeutic effects in LPS-induced ALI by inhibiting NF-κB and activating Nrf2 signaling pathways.

  13. The Role of Nrf2-Mediated Pathway in Cardiac Remodeling and Heart Failure

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    Shanshan Zhou

    2014-01-01

    Full Text Available Heart failure (HF is frequently the consequence of sustained, abnormal neurohormonal, and mechanical stress and remains a leading cause of death worldwide. The key pathophysiological process leading to HF is cardiac remodeling, a term referring to maladaptation to cardiac stress at the molecular, cellular, tissue, and organ levels. HF and many of the conditions that predispose one to HF are associated with oxidative stress. Increased generation of reactive oxygen species (ROS in the heart can directly lead to increased necrosis and apoptosis of cardiomyocytes which subsequently induce cardiac remodeling and dysfunction. Nuclear factor-erythroid-2- (NF-E2- related factor 2 (Nrf2 is a transcription factor that controls the basal and inducible expression of a battery of antioxidant genes and other cytoprotective phase II detoxifying enzymes that are ubiquitously expressed in the cardiovascular system. Emerging evidence has revealed that Nrf2 and its target genes are critical regulators of cardiovascular homeostasis via the suppression of oxidative stress, which is the key player in the development and progression of HF. The purpose of this review is to summarize evidence that activation of Nrf2 enhances endogenous antioxidant defenses and counteracts oxidative stress-associated cardiac remodeling and HF.

  14. Dietary moderately oxidized oil activates the Nrf2 signaling pathway in the liver of pigs

    Directory of Open Access Journals (Sweden)

    Varady Juliane

    2012-02-01

    Full Text Available Abstract Background Previous studies have shown that administration of oxidized oils increases gene expression and activities of various enzymes involved in xenobiotic metabolism and stress response in the liver of rats and guinea pigs. As these genes are controlled by nuclear factor erythroid-derived 2-like 2 (Nrf2, we investigated the hypothesis that feeding of oxidized fats causes an activation of that transcription factor in the liver which in turn activates the expression of antioxidant, cytoprotective and detoxifying genes. Methods Twenty four crossbred pigs were allocated to two groups of 12 pigs each and fed nutritionally adequate diets with either fresh rapeseed oil (fresh fat group or oxidized rapeseed oil prepared by heating at a temperature of 175°C for 72 h (oxidized fat group. Results After 29 days of feeding, pigs of the oxidized fat group had a markedly increased nuclear concentration of the transcription factor Nrf2 and a higher activity of cellular superoxide dismutase and T4-UDP glucuronosyltransferase in liver than the fresh fat group (P P Conclusion The present study shows for the first time that administration of an oxidized fat activates the Nrf2 in the liver of pigs which likely reflects an adaptive mechanism to prevent cellular oxidative damage. Activation of the NF-κB pathway might also contribute to this effect of oxidized fat.

  15. Sulforaphane Induces Nrf2 and Protects Against CYP2E1-dependent Binge Alcohol –induced Liver Steatosis

    Science.gov (United States)

    Zhou, Richard; Lin, Jianjun; Wu, Defeng

    2013-01-01

    Background The mechanism(s) by which alcohol causes cell injury are still not clear but a major mechanism appears to be the role of lipid peroxidation and oxidative stress in alcohol toxicity. CYP2E1-generated ROS contributes to the ethanol-induced oxidant stress and inhibition of CYP2E1 activity decreases ethanol-induced fatty liver. The transcription factor Nrf2 regulates the expression of many cytoprotective enzymes which results in cellular protection against a variety of toxins. Method The current study was designed to evaluate the ability of sulforaphane, an activator of Nrf2, to blunt CYP2E1-dependent, ethanol-induced steatosis in vivo and in vitro. Results The sulforaphane treatment activated Nrf2, increased levels of the Nrf2 target heme oxygenase -1 and subsequently lowered oxidant stress as shown by the decline in lipid peroxidation and 3-Nitrotyrosine protein adducts and an increase in GSH levels after the acute ethanol treatment. It decreased ethanol-elevated liver levels of triglycerides and cholesterol and Oil Red O staining. Similar results were found in vitro as addition of sulforaphane to HepG2 E47 cells, which express CYP2E1, elevated Nrf2 levels and decreased the accumulation of lipid in cells cultured with ethanol. Sulforaphane treatment had no effect on levels of or activity of CYP2E1. Conclusions Sulforaphane proved to be an effective in vivo inhibitor of acute ethanol–induced fatty liver in mice. General significance The possible amelioration of liver injury which occurs under these conditions by chemical activators of Nrf2 is of clinical relevance and worthy of further study. PMID:24060752

  16. Sulforaphane induces Nrf2 and protects against CYP2E1-dependent binge alcohol-induced liver steatosis.

    Science.gov (United States)

    Zhou, Richard; Lin, Jianjun; Wu, Defeng

    2014-01-01

    The mechanism(s) by which alcohol causes cell injury are still not clear but a major mechanism appears to be the role of lipid peroxidation and oxidative stress in alcohol toxicity. CYP2E1-generated ROS contributes to the ethanol-induced oxidant stress and inhibition of CYP2E1 activity decreases ethanol-induced fatty liver. The transcription factor Nrf2 regulates the expression of many cytoprotective enzymes which results in cellular protection against a variety of toxins. The current study was designed to evaluate the ability of sulforaphane, an activator of Nrf2, to blunt CYP2E1-dependent, ethanol-induced steatosis in vivo and in vitro. The sulforaphane treatment activated Nrf2, increased levels of the Nrf2 target heme oxygenase-1 and subsequently lowered oxidant stress as shown by the decline in lipid peroxidation and 3-nitrotyrosine protein adducts and an increase in GSH levels after the acute ethanol treatment. It decreased ethanol-elevated liver levels of triglycerides and cholesterol and Oil Red O staining. Similar results were found in vitro as addition of sulforaphane to HepG2 E47 cells, which express CYP2E1, elevated Nrf2 levels and decreased the accumulation of lipid in cells cultured with ethanol. Sulforaphane treatment had no effect on levels of or activity of CYP2E1. Sulforaphane proved to be an effective in vivo inhibitor of acute ethanol-induced fatty liver in mice. The possible amelioration of liver injury which occurs under these conditions by chemical activators of Nrf2 is of clinical relevance and worthy of further study. © 2013.

  17. Calycosin regulates glucocorticoid-induced apoptosis via Nrf2/ARE ...

    African Journals Online (AJOL)

    Calycosin regulates glucocorticoid-induced apoptosis via Nrf2/ARE signaling in MC3T3-E1 cells. ... If you would like more information about how to print, save, and work with PDFs, Highwire Press provides a helpful Frequently Asked Questions about PDFs. Alternatively, you can download the PDF file directly to your ...

  18. Calycosin regulates glucocorticoid-induced apoptosis via Nrf2/ARE ...

    African Journals Online (AJOL)

    treatment decreased expression levels of caspase-3/-8/-9 and PARP. In addition, DEX treatment significantly suppressed the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2) as well as its downstream targets, viz, heme oxygenase-1 and quinone oxidoreductase-1. Interestingly, CA treatment reversed this ...

  19. The PTEN/NRF2 Axis Promotes Human Carcinogenesis

    DEFF Research Database (Denmark)

    Rojo, Ana I; Rada, Patricia; Mendiola, Marta

    2014-01-01

    UNLABELLED: Abstract Aims: A recent study conducted in mice reported that liver-specific knockout of tumor suppressor Pten augments nuclear factor (erythroid-derived 2)-like 2 (NRF2) transcriptional activity. Here, we further investigated how phosphatase and tensin homolog deleted on chromosome 1...

  20. Fumaric acid esters stimulate astrocytic VEGF expression through HIF-1α and Nrf2.

    Directory of Open Access Journals (Sweden)

    Diana Wiesner

    Full Text Available Fumaric acid esters (FAE are oral analogs of fumarate that have recently been shown to decrease relapse rate and disease progression in multiple sclerosis (MS, prompting to investigate their protective potential in other neurological diseases such as amyotrophic lateral sclerosis (ALS. Despite efficacy in MS, mechanisms of action of FAEs are still largely unknown. FAEs are known to activate the transcription factor Nrf2 and downstream anti-oxidant responses through the succination of Nrf2 inhibitor KEAP1. However, fumarate is also a known inhibitor of prolyl-hydroxylases domain enzymes (PhD, and PhD inhibition might lead to stabilization of the HIF-1α transcription factor under normoxic conditions and subsequent activation of a pseudo hypoxic response. Whether Nrf2 activation is associated with HIF-1α stabilization in response to FAEs in cell types relevant to MS or ALS remains unknown. Here, we show that FAEs elicit HIF-1α accumulation, and VEGF release as its expected consequence, in astrocytes but not in other cell types of the central nervous system. Reporter assays demonstrated that increased astrocytic VEGF release in response to FAEs was dependent upon both HIF-1α and Nrf2 activation. Last, astrocytes of transgenic mice expressing SOD1(G93A, an animal model of ALS, displayed reduced VEGF release in response to FAEs. These studies show that FAEs elicit different signaling pathways in cell types from the central nervous system, in particular a pseudo-hypoxic response in astrocytes. Disease relevant mutations might affect this response.

  1. Role of Nrf2 and protective effects of Metformin against tobacco smoke-induced cerebrovascular toxicity

    Directory of Open Access Journals (Sweden)

    Shikha Prasad

    2017-08-01

    Full Text Available Cigarette smoking (CS is associated with vascular endothelial dysfunction in a causative way primarily related to the TS content of reactive oxygen species (ROS, nicotine, and inflammation. TS promotes glucose intolerance and increases the risk of developing type-2 diabetes mellitus (2DM with which it shares other pathogenic traits including the high risk of cerebrovascular and neurological disorders like stroke via ROS generation, inflammation, and blood-brain barrier (BBB impairment. Herein we provide evidence of the role played by nuclear factor erythroid 2-related factor (Nrf2 in CS-induced cerebrobvascular/BBB impairments and how these cerebrovascular harmful effects can be circumvented by the use of metformin (MF; a widely prescribed, firstline anti-diabetic drug treatment. Our data in fact revealed that MF activates counteractive mechanisms primarily associated with the Nrf2 pathway which drastically reduce CS toxicity at the cerebrovascular level. These include the suppression of tight junction (TJ protein downregulation and loss of BBB integrity induced by CS, reduction of inflammation and oxidative stress, renormalization of the expression levels of the major BBB glucose transporter Glut-1 and that of the anticoagulant factor thrombomodulin. Further, we provide additional insights on the controversial interplay between Nrf2 and AMPK.

  2. NRF2 Orchestrates the Metabolic Shift during Induced Pluripotent Stem Cell Reprogramming

    Directory of Open Access Journals (Sweden)

    Kate E. Hawkins

    2016-03-01

    Full Text Available The potential of induced pluripotent stem cells (iPSCs in disease modeling and regenerative medicine is vast, but current methodologies remain inefficient. Understanding the cellular mechanisms underlying iPSC reprogramming, such as the metabolic shift from oxidative to glycolytic energy production, is key to improving its efficiency. We have developed a lentiviral reporter system to assay longitudinal changes in cell signaling and transcription factor activity in living cells throughout iPSC reprogramming of human dermal fibroblasts. We reveal early NF-κB, AP-1, and NRF2 transcription factor activation prior to a temporal peak in hypoxia inducible factor α (HIFα activity. Mechanistically, we show that an early burst in oxidative phosphorylation and elevated reactive oxygen species generation mediates increased NRF2 activity, which in turn initiates the HIFα-mediated glycolytic shift and may modulate glucose redistribution to the pentose phosphate pathway. Critically, inhibition of NRF2 by KEAP1 overexpression compromises metabolic reprogramming and results in reduced efficiency of iPSC colony formation.

  3. Ketone body 3-hydroxybutyrate mimics calorie restriction via the Nrf2 activator, fumarate, in the retina.

    Science.gov (United States)

    Izuta, Yusuke; Imada, Toshihiro; Hisamura, Ryuji; Oonishi, Erina; Nakamura, Shigeru; Inagaki, Emi; Ito, Masataka; Soga, Tomoyoshi; Tsubota, Kazuo

    2018-02-01

    Calorie restriction (CR) being the most robust dietary intervention provides various health benefits. D-3-hydroxybutyrate (3HB), a major physiological ketone, has been proposed as an important endogenous molecule for CR. To investigate the role of 3HB in CR, we investigated potential shared mechanisms underlying increased retinal 3HB induced by CR and exogenously applied 3HB without CR to protect against ischemic retinal degeneration. The repeated elevation of retinal 3HB, with or without CR, suppressed retinal degeneration. Metabolomic analysis showed that the antioxidant pentose phosphate pathway and its limiting enzyme, glucose-6-phosphate dehydrogenase (G6PD), were concomitantly preserved. Importantly, the upregulation of nuclear factor erythroid 2 p45-related factor 2 (Nrf2), a regulator of G6PD, and elevation of the tricarboxylic acid cycle's Nrf2 activator, fumarate, were also shared. Together, our findings suggest that CR provides retinal antioxidative defense by 3HB through the antioxidant Nrf2 pathway via modification of a tricarboxylic acid cycle intermediate during 3HB metabolism. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  4. Effects of Glucagon-Like Peptide-1 on Oxidative Stress and Nrf2 Signaling

    Directory of Open Access Journals (Sweden)

    Yoon Sin Oh

    2017-12-01

    Full Text Available Oxidative cellular damage caused by free radicals is known to contribute to the pathogenesis of various diseases such as cancer, diabetes, and neurodegenerative diseases, as well as to aging. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2 and Kelch-like ECH-associated protein1 (Keap1 signaling pathways play an important role in preventing stresses including oxidative and inflammatory stresses. Nrf2 is a master regulator of cellular stress responses, induces the expression of antioxidant and detoxification enzymes, and protects against oxidative stress-induced cell damage. Glucagon-like peptide-1 (GLP-1 is an incretin hormone, which was originally found to increase insulin synthesis and secretion. It is now widely accepted that GLP-1 has multiple functions beyond glucose control in various tissues and organs including brain, kidney, and heart. GLP-1 and GLP-1 receptor agonists are known to be effective in many chronic diseases, including diabetes, via antioxidative mechanisms. In this review, we summarize the current knowledge regarding the role of GLP-1 in the protection against oxidative damage and the activation of the Nrf2 signaling pathway.

  5. Agmatine, by Improving Neuroplasticity Markers and Inducing Nrf2, Prevents Corticosterone-Induced Depressive-Like Behavior in Mice.

    Science.gov (United States)

    Freitas, Andiara E; Egea, Javier; Buendia, Izaskun; Gómez-Rangel, Vanessa; Parada, Esther; Navarro, Elisa; Casas, Ana Isabel; Wojnicz, Aneta; Ortiz, José Avendaño; Cuadrado, Antonio; Ruiz-Nuño, Ana; Rodrigues, Ana Lúcia S; Lopez, Manuela G

    2016-07-01

    Agmatine, an endogenous neuromodulator, is a potential candidate to constitute an adjuvant/monotherapy for the management of depression. A recent study by our group demonstrated that agmatine induces Nrf2 and protects against corticosterone effects in a hippocampal neuronal cell line. The present study is an extension of this previous study by assessing the antidepressant-like effect of agmatine in an animal model of depression induced by corticosterone in mice. Swiss mice were treated simultaneously with agmatine or imipramine at a dose of 0.1 mg/kg/day (p.o.) and corticosterone for 21 days and the daily administrations of experimental drugs were given immediately prior to corticosterone (20 mg/kg/day, p.o.) administrations. Wild-type C57BL/6 mice (Nrf2 (+/+)) and Nrf2 KO (Nrf2 (-/-)) were treated during 21 days with agmatine (0.1 mg/kg/day, p.o.) or vehicle. Twenty-four hours after the last treatments, the behavioral tests and biochemical assays were performed. Agmatine treatment for 21 days was able to abolish the corticosterone-induced depressive-like behavior and the alterations in the immunocontent of mature BDNF and synaptotagmin I, and in the serotonin and glutamate levels. Agmatine also abolished the corticosterone-induced changes in the morphology of astrocytes and microglia in CA1 region of hippocampus. In addition, agmatine treatment in control mice increased noradrenaline, serotonin, and dopamine levels, CREB phosphorylation, mature BDNF and synaptotagmin I immunocontents, and reduced pro-BDNF immunocontent in the hippocampus. Agmatine's ability to produce an antidepressant-like effect was abolished in Nrf2 (-/-) mice. The present results reinforce the participation of Nrf2 in the antidepressant-like effect produced by agmatine and expand literature data concerning its mechanisms of action.

  6. The Nrf2-inducers tanshinone I and dihydrotanshinone protect human skin cells and reconstructed human skin against solar simulated UV☆

    Science.gov (United States)

    Tao, Shasha; Justiniano, Rebecca; Zhang, Donna D.; Wondrak, Georg T.

    2013-01-01

    Exposure to solar ultraviolet (UV) radiation is a causative factor in skin photocarcinogenesis and photoaging, and an urgent need exists for improved strategies for skin photoprotection. The redox-sensitive transcription factor Nrf2 (nuclear factor-E2-related factor 2), a master regulator of the cellular antioxidant defense against environmental electrophilic insult, has recently emerged as an important determinant of cutaneous damage from solar UV, and the concept of pharmacological activation of Nrf2 has attracted considerable attention as a novel approach to skin photoprotection. In this study, we examined feasibility of using tanshinones, a novel class of phenanthrenequinone-based cytoprotective Nrf2 inducers derived from the medicinal plant Salvia miltiorrhiza, for protection of cultured human skin cells and reconstructed human skin against solar simulated UV. Using a dual luciferase reporter assay in human Hs27 dermal fibroblasts pronounced transcriptional activation of Nrf2 by four major tanshinones [tanshinone I (T-I), dihydrotanshinone (DHT), tanshinone IIA (T-II-A) and cryptotanshinone (CT)] was detected. In fibroblasts, the more potent tanshinones T-I and DHT caused a significant increase in Nrf2 protein half-life via blockage of ubiquitination, ultimately resulting in upregulated expression of cytoprotective Nrf2 target genes (GCLC, NQO1) with the elevation of cellular glutathione levels. Similar tanshinone-induced changes were also observed in HaCaT keratinocytes. T-I and DHT pretreatment caused significant suppression of skin cell death induced by solar simulated UV and riboflavin-sensitized UVA. Moreover, feasibility of tanshinone-based cutaneous photoprotection was tested employing a human skin reconstruct exposed to solar simulated UV (80 mJ/cm2 UVB; 1.53 J/cm2 UVA). The occurrence of markers of epidermal solar insult (cleaved procaspase 3, pycnotic nuclei, eosinophilic cytoplasm, acellular cavities) was significantly attenuated in DHT

  7. The Nrf2-inducers tanshinone I and dihydrotanshinone protect human skin cells and reconstructed human skin against solar simulated UV.

    Science.gov (United States)

    Tao, Shasha; Justiniano, Rebecca; Zhang, Donna D; Wondrak, Georg T

    2013-01-01

    Exposure to solar ultraviolet (UV) radiation is a causative factor in skin photocarcinogenesis and photoaging, and an urgent need exists for improved strategies for skin photoprotection. The redox-sensitive transcription factor Nrf2 (nuclear factor-E2-related factor 2), a master regulator of the cellular antioxidant defense against environmental electrophilic insult, has recently emerged as an important determinant of cutaneous damage from solar UV, and the concept of pharmacological activation of Nrf2 has attracted considerable attention as a novel approach to skin photoprotection. In this study, we examined feasibility of using tanshinones, a novel class of phenanthrenequinone-based cytoprotective Nrf2 inducers derived from the medicinal plant Salvia miltiorrhiza, for protection of cultured human skin cells and reconstructed human skin against solar simulated UV. Using a dual luciferase reporter assay in human Hs27 dermal fibroblasts pronounced transcriptional activation of Nrf2 by four major tanshinones [tanshinone I (T-I), dihydrotanshinone (DHT), tanshinone IIA (T-II-A) and cryptotanshinone (CT)] was detected. In fibroblasts, the more potent tanshinones T-I and DHT caused a significant increase in Nrf2 protein half-life via blockage of ubiquitination, ultimately resulting in upregulated expression of cytoprotective Nrf2 target genes (GCLC, NQO1) with the elevation of cellular glutathione levels. Similar tanshinone-induced changes were also observed in HaCaT keratinocytes. T-I and DHT pretreatment caused significant suppression of skin cell death induced by solar simulated UV and riboflavin-sensitized UVA. Moreover, feasibility of tanshinone-based cutaneous photoprotection was tested employing a human skin reconstruct exposed to solar simulated UV (80 mJ/cm(2) UVB; 1.53 J/cm(2) UVA). The occurrence of markers of epidermal solar insult (cleaved procaspase 3, pycnotic nuclei, eosinophilic cytoplasm, acellular cavities) was significantly attenuated in DHT

  8. The Nrf2-inducers tanshinone I and dihydrotanshinone protect human skin cells and reconstructed human skin against solar simulated UV

    Directory of Open Access Journals (Sweden)

    Shasha Tao

    2013-01-01

    Full Text Available Exposure to solar ultraviolet (UV radiation is a causative factor in skin photocarcinogenesis and photoaging, and an urgent need exists for improved strategies for skin photoprotection. The redox-sensitive transcription factor Nrf2 (nuclear factor-E2-related factor 2, a master regulator of the cellular antioxidant defense against environmental electrophilic insult, has recently emerged as an important determinant of cutaneous damage from solar UV, and the concept of pharmacological activation of Nrf2 has attracted considerable attention as a novel approach to skin photoprotection. In this study, we examined feasibility of using tanshinones, a novel class of phenanthrenequinone-based cytoprotective Nrf2 inducers derived from the medicinal plant Salvia miltiorrhiza, for protection of cultured human skin cells and reconstructed human skin against solar simulated UV. Using a dual luciferase reporter assay in human Hs27 dermal fibroblasts pronounced transcriptional activation of Nrf2 by four major tanshinones [tanshinone I (T-I, dihydrotanshinone (DHT, tanshinone IIA (T-II-A and cryptotanshinone (CT] was detected. In fibroblasts, the more potent tanshinones T-I and DHT caused a significant increase in Nrf2 protein half-life via blockage of ubiquitination, ultimately resulting in upregulated expression of cytoprotective Nrf2 target genes (GCLC, NQO1 with the elevation of cellular glutathione levels. Similar tanshinone-induced changes were also observed in HaCaT keratinocytes. T-I and DHT pretreatment caused significant suppression of skin cell death induced by solar simulated UV and riboflavin-sensitized UVA. Moreover, feasibility of tanshinone-based cutaneous photoprotection was tested employing a human skin reconstruct exposed to solar simulated UV (80 mJ/cm2 UVB; 1.53 J/cm2 UVA. The occurrence of markers of epidermal solar insult (cleaved procaspase 3, pycnotic nuclei, eosinophilic cytoplasm, acellular cavities was significantly attenuated in DHT

  9. CD36 Upregulation Mediated by Intranasal LV-NRF2 Treatment Mitigates Hypoxia-Induced Progression of Alzheimer's-Like Pathogenesis

    Science.gov (United States)

    Wang, Chun-Yan; Xie, Jing-Wei; Cai, Jian-Hui; Wang, Tao; Xu, Ye; Wang, Xu

    2014-01-01

    Abstract Aims: There is extensive evidence that oxidative stress induces cellular dysfunction in the brain and plays a critical role in Alzheimer's disease (AD) pathogenesis. Hypoxia increases factors involved in oxidative stress injury and contributes to the onset and progression of AD. Nuclear factor erythroid 2-related factor 2 (NRF2), a major component regulating antioxidant response, is attenuated in the AD brain. Importantly, NRF2 directly regulates the alternative first exons of CD36, an important participant in oxidative and inflammatory processes. To explore the effects of hypoxia-induced deterioration of AD-like pathogenesis and investigate the correlation between hypoxia-induced NRF2 signal alterations and CD36 expression, we examined the NRF2 signaling, CD36, and oxidative stress events in hypoxia-treated APPswe/PSEN1dE9 (APP/PS1) mice brain. Results: We observed that hypoxia treatment increased oxidative stress, exacerbated inflammation, and aggravated learning defects in aged APP/PS1 mice. Microglia from hypoxia-treated mice brain exhibited marked reduction in CD36 expression and inhibition of β-amyloid (Aβ) degradation. Accordingly, hypoxia treatment caused a decrease in transactivation of NRF2 target genes in the aging mouse brain. Intranasal administration with a lentiviral vector encoding human NRF2 increased CD36 expression, ameliorated the weak antioxidant response triggered by hypoxia, diminished Aβ deposition, and improved spatial memory defects. Innovation: In this study, we demonstrated for the first time that NRF2 intranasal treatment-induced increases of CD36 could enhance Aβ clearance in AD transgenic mouse. Conclusion: These results suggest that targeting NRF2-mediated CD36 expression might provide a beneficial intervention for cognitive impairment and oxidative stress in AD progression. Antioxid. Redox Signal. 21, 2208–2230. PMID:24702189

  10. Induction of cancer chemopreventive enzymes by coffee is mediated by transcription factor Nrf2. Evidence that the coffee-specific diterpenes cafestol and kahweol confer protection against acrolein

    International Nuclear Information System (INIS)

    Higgins, Larry G.; Cavin, Christophe; Itoh, Ken; Yamamoto, Masayuki; Hayes, John D.

    2008-01-01

    Mice fed diets containing 3% or 6% coffee for 5 days had increased levels of mRNA for NAD(P)H:quinone oxidoreductase 1 (NQO1) and glutathione S-transferase class Alpha 1 (GSTA1) of between 4- and 20-fold in the liver and small intestine. Mice fed 6% coffee also had increased amounts of mRNA for UDP-glucuronosyl transferase 1A6 (UGT1A6) and the glutamate cysteine ligase catalytic (GCLC) subunit of between 3- and 10-fold in the small intestine. Up-regulation of these mRNAs was significantly greater in mice possessing Nrf2 (NF-E2 p45 subunit-related factor 2) than those lacking the transcription factor. Basal levels of mRNAs for NQO1, GSTA1, UGT1A6 and GCLC were lower in tissues from nrf2 -/- mice than from nrf2 +/+ mice, but modest induction occurred in the mutant animals. Treatment of mouse embryonic fibroblasts (MEFs) from nrf2 +/+ mice with either coffee or the coffee-specific diterpenes cafestol and kahweol (C + K) increased NQO1 mRNA up to 9-fold. MEFs from nrf2 -/- mice expressed less NQO1 mRNA than did wild-type MEFs, but NQO1 was induced modestly by coffee or C + K in the mutant fibroblasts. Transfection of MEFs with nqo1-luciferase reporter constructs showed that induction by C + K was mediated primarily by Nrf2 and required the presence of an antioxidant response element in the 5'-upstream region of the gene. Luciferase reporter activity did not increase following treatment of MEFs with 100 μmol/l furan, suggesting that this ring structure within C + K is insufficient for gene induction. Priming of nrf2 +/+ MEFs, but not nrf2 -/- MEFs, with C + K conferred 2-fold resistance towards acrolein

  11. Effect of coffee combining green coffee bean constituents with typical roasting products on the Nrf2/ARE pathway in vitro and in vivo.

    Science.gov (United States)

    Volz, Nadine; Boettler, Ute; Winkler, Swantje; Teller, Nicole; Schwarz, Christoph; Bakuradze, Tamara; Eisenbrand, Gerhard; Haupt, Larissa; Griffiths, Lyn R; Stiebitz, Herbert; Bytof, Gerhard; Lantz, Ingo; Lang, Roman; Hofmann, Thomas; Somoza, Veronika; Marko, Doris

    2012-09-26

    This study investigated Nrf2-activating properties of a coffee blend combining raw coffee bean constituents with 5-O-caffeoylquinic acid (CGA) as a lead component with typical roasting products such as N-methylpyridinium (NMP). In cell culture (HT29) the respective coffee extract (CN-CE) increased nuclear Nrf2 translocation and enhanced the transcription of ARE-dependent genes as exemplified for NAD(P)H:quinone oxidoreductase and glutathione-S-transferase (GST)A1, reflected in the protein level by an increase in GST enzyme activity. In a pilot human intervention study (29 healthy volunteers), daily consumption of 750 mL of CN-coffee for 4 weeks increased Nrf2 transcription in peripheral blood lymphocytes on average. However, the transcriptional response pattern of Nrf2/ARE-dependent genes showed substantial interindividual variations. The presence of SNPs in the Nrf2-promoter, reported recently, as well as the detection of GSTT1*0 (null) genotypes in the study collective strengthens the hypothesis that coffee acts as a modulator of Nrf2-dependent gene response in humans, but genetic polymorphisms play an important role in the individual response pattern.

  12. Differential effect of covalent protein modification and glutathione depletion on the transcriptional response of Nrf2 and NF-kappaB.

    Science.gov (United States)

    Chia, Alvin J L; Goldring, Christopher E; Kitteringham, Neil R; Wong, Shi Quan; Morgan, Paul; Park, B Kevin

    2010-08-01

    Liver injury associated with exposure to therapeutic agents that undergo hepatic metabolism can involve the formation of reactive metabolites. These may cause redox perturbation which can result in oxidative stress as well as protein modification leading to activation or inhibition of cellular transcriptional responses. Nevertheless, the effects of these challenges on more than one transcriptional pathway simultaneously remain unclear. We have investigated two transcription factors known to be sensitive to electrophilic stress and redox perturbation, Nrf2 and NF-kappaB, in mouse liver cells. Cellular stress was induced by the probes: N-acetyl-p-benzoquinineimine (NAPQI), the reactive metabolite of acetaminophen; dinitrochlorobenzene (DNCB), a model electrophile; and buthionine (S,R)-sulfoximine (BSO), an inhibitor of glutamate-cysteine ligase. NAPQI, DNCB and BSO can all cause glutathione (GSH) depletion; however only NAPQI and DNCB can covalently bind proteins. We also employed RNAi to manipulate Keap1 (the inhibitor of Nrf2), Nrf2 itself and NF-kappaB-p65, to understand their roles in the response to drug stress. All three chemicals induced Nrf2, but NF-kappaB binding activity was only increased after BSO treatment. In fact, NF-kappaB binding activity decreased after exposure to NAPQI and DNCB. While RNAi depletion of Keap1 led to reduced toxicity following exposure to DNCB, depletion of Nrf2 and NF-kappaB augmented toxicity. Interestingly, increased Nrf2 caused by Keap1 depletion was reversed by co-depletion of NF-kappaB. We demonstrate that Keap1/Nrf2 and NF-kappaB respond differently to electrophiles that bind proteins covalently and the redox perturbation associated with glutathione depletion, and that crosstalk may enable NF-kappaB to partly influence Nrf2 expression during cellular stress. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  13. Cancer Chemoprevention by Traditional Chinese Herbal Medicine and Dietary Phytochemicals: Targeting Nrf2-Mediated Oxidative Stress/Anti-Inflammatory Responses, Epigenetics, and Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Jong Hun Lee

    2013-01-01

    Full Text Available Excessive oxidative stress induced by reactive oxygen species (ROS, reactive nitrogen species (RNS, and reactive metabolites of carcinogens alters cellular homeostasis, leading to genetic/epigenetic changes, genomic instability, neoplastic transformation, and cancer initiation/progression. As a protective mechanism against oxidative stress, antioxidant/detoxifying enzymes reduce these reactive species and protect normal cells from endo-/exogenous oxidative damage. The transcription factor nuclear factor-erythroid 2 p45 (NF-E2-related factor 2 (Nrf2, a master regulator of the antioxidative stress response, plays a critical role in the expression of many cytoprotective enzymes, including NAD(PH:quinine oxidoreductase (NQO1, heme oxygenase-1 (HO-1, UDP-glucuronosyltransferase (UGT, and glutathione S-transferase (GST. Recent studies demonstrated that many dietary phytochemicals derived from various vegetables, fruits, spices, and herbal medicines induce Nrf2-mediated antioxidant/detoxifying enzymes, restore aberrant epigenetic alterations, and eliminate cancer stem cells (CSCs. The Nrf2-mediated antioxidant response prevents many age-related diseases, including cancer. Owing to their fundamental contribution to carcinogenesis, epigenetic modifications and CSCs are novel targets of dietary phytochemicals and traditional Chinese herbal medicine (TCHM. In this review, we summarize cancer chemoprevention by dietary phytochemicals, including TCHM, which have great potential as a safer and more effective strategy for preventing cancer.

  14. Curcumin attenuates lipopolysaccharide/d-galactosamine-induced acute liver injury by activating Nrf2 nuclear translocation and inhibiting NF-kB activation.

    Science.gov (United States)

    Xie, Yi-Lian; Chu, Jin-Guo; Jian, Xiao-Min; Dong, Jin-Zhong; Wang, Li-Ping; Li, Guo-Xiang; Yang, Nai-Bin

    2017-07-01

    Curcumin, a polyphenol in curry spice isolated from the rhizome of turmeric, has been reported to possess versatile biological properties including anti-inflammatory, anti-oxidant, antifibrotic, and anticancer activities. In this study, the hepatoprotective effect of curcumin was investigated in lipopolysaccharide (LPS)/d-galactosamine (d-GalN)-induced acute liver injury (ALI) in rats. Experimental ALI was induced with an intraperitoneal (ip) injection of sterile 0.9% sodium chloride (NaCl) solution containing 8μg LPS and 800mg/kg d-GalN. Curcumin was administered once daily starting three days prior to LPS/d-GalN treatment. Results indicated that curcumin could attenuate hepatic pathological damage, decrease serum ALT and AST levels, and reduce malondialdehyde (MDA) content in experimental ALI rats. Moreover, higher dosages of curcumin pretreatment inhibited NF-κB activation and reduced serum TNF-α and liver TNF-α levels induced by LPS/d-GalN ip injection. Furthermore, we found that curcumin up-regulated the expression of nuclear Nrf2 and Nrf2-dependent antioxidant defense genes including heme oxygenase-1 (HO-1), glutamate-cysteine ligase (GCLC), NAD(P)H dehydrogenase, and quinone (NQO-1) in a dose-dependent manner. Our results showed that curcumin protected experimental animals against LPS/d-GalN-induced ALI through activation of Nrf2 nuclear translocation and inhibition of NF-κB activation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  15. Topical Bixin Confers NRF2-Dependent Protection Against Photodamage and Hair Graying in Mouse Skin

    Science.gov (United States)

    Rojo de la Vega, Montserrat; Zhang, Donna D.; Wondrak, Georg T.

    2018-01-01

    Environmental exposure to solar ultraviolet (UV) radiation causes acute photodamage, premature aging, and skin cancer, attributable to UV-induced genotoxic, oxidative, and inflammatory stress. The transcription factor NRF2 [nuclear factor erythroid 2 (E2)-related factor 2] is the master regulator of the cellular antioxidant response protecting skin against various environmental stressors including UV radiation and electrophilic pollutants. NRF2 in epidermal keratinocytes can be activated using natural chemopreventive compounds such as the apocarotenoid bixin, an FDA-approved food additive and cosmetic ingredient from the seeds of the achiote tree (Bixa orellana). Here, we tested the feasibility of topical use of bixin for NRF2-dependent skin photoprotection in two genetically modified mouse models [SKH1 and C57BL/6J (Nrf2+/+ versus Nrf2-/-)]. First, we observed that a bixin formulation optimized for topical NRF2 activation suppresses acute UV-induced photodamage in Nrf2+/+ but not Nrf2-/- SKH1 mice, a photoprotective effect indicated by reduced epidermal hyperproliferation and oxidative DNA damage. Secondly, it was demonstrated that topical bixin suppresses PUVA (psoralen + UVA)-induced hair graying in Nrf2+/+ but not Nrf2-/- C57BL/6J mice. Collectively, this research provides the first in vivo evidence that topical application of bixin can protect against UV-induced photodamage and PUVA-induced loss of hair pigmentation through NRF2 activation. Topical NRF2 activation using bixin may represent a novel strategy for human skin photoprotection, potentially complementing conventional sunscreen-based approaches. PMID:29636694

  16. The effect of Mastin® on expression of Nrf2 in the rat heart with subtotally nephrectomy chronic Kidney disease model

    Science.gov (United States)

    Nathania, J.; Soetikno, V.

    2017-08-01

    Chronic kidney disease (CKD) is increasingly prevalent in Indonesia and worldwide. One of the major causes of morbidity and mortality in CKD is the complication of cardiovascular disease. Mastin® is a supplement that is locally produced in Indonesia and is made from extract of mangosteen pericarp, which is reported to have antioxidative, anti-inflammatory, and antitumor properties. The present study aimed to investigate whether Mastin® could improve antioxidant responses in the rat heart during CKD by measuring the expression of nuclear factor erythroid-2-related factor (Nrf)2, a master regulator of antioxidant response elements. RNA was extracted from the heart tissue of three groups of rats: a normal group, a nephrectomy group, and a nephrectomy with Mastin® group. Two-step real-time RT-PCR was then conducted to calculate the relative expression of the Nrf2 gene. Nrf2 expression was markedly decreased in the nephrectomy group vs the normal group, but slightly increas ed in the nephrectomy with Mastin® group vs the nephrectomy group. CKD resulted in impaired activation of the Nrf2 pathway in the rat heart. Although the administration of Mastin® slightly increased Nrf2 expression, it was not enough to confer cardioprotective effects through the Nrf2 pathway.

  17. Induction of the pi class of glutathione S-transferase by carnosic acid in rat Clone 9 cells via the p38/Nrf2 pathway.

    Science.gov (United States)

    Lin, Chia-Yuan; Wu, Chi-Rei; Chang, Shu-Wei; Wang, Yu-Jung; Wu, Jia-Jiuan; Tsai, Chia-Wen

    2015-06-01

    Induction of phase II enzymes is important in cancer chemoprevention. We compared the effect of rosemary diterpenes on the expression of the pi class of glutathione S-transferase (GSTP) in rat liver Clone 9 cells and the signaling pathways involved. Culturing cells with 1, 5, 10, or 20 μM carnosic acid (CA) or carnosol (CS) for 24 h in a dose-dependent manner increased the GSTP expression. CA was more potent than