151
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McCarty MF. Nutraceutical strategies for ameliorating the toxic effects of alcohol. Med Hypotheses 2013; 80:456-62. [PMID: 23380360 DOI: 10.1016/j.mehy.2012.12.040] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 12/29/2012] [Indexed: 12/26/2022]
Abstract
Rodent studies reveal that oxidative stress, much of it generated via induction/activation of NADPH oxidase, is a key mediator of a number of the pathogenic effects of chronic ethanol overconsumption. The highly reactive ethanol metabolite acetaldehyde is a key driver of this oxidative stress, and doubtless works in other ways to promote alcohol-induced pathology. Effective antioxidant measure may therefore be useful for mitigating the adverse health consequences of alcohol consumption; spirulina may have particular utility in this regard, as its chief phycochemical phycocyanobilin has recently been shown to function as an inhibitor of certain NADPH oxidase complexes, mimicking the physiological role of its chemical relatives biliverdin/bilirubin in this respect. Moreover, certain nutraceuticals, including taurine, pantethine, and lipoic acid, may have the potential to boost the activity of the mitochondrial isoform of aldehyde dehydrogenase, ALDH-2, accelerating conversion of acetaldehyde to acetate (which arguably has protective health effects). Little noticed clinical studies conducted nearly three decades ago reported that pre-ingestion of either taurine or pantethine could blunt the rise in blood acetaldehyde following ethanol consumption. Other evidence suggests that lipoic acid may function within mitochondria to maintain aldehyde dehydrogenase in a reduced active conformation; the impact of this agent on ethanol metabolism has however received little or no study. Studies evaluating the impact of nutracetical strategies on prevention of hangovers - which likely are mediated by acetaldehyde - may represent a quick, low-cost way to identify nutraceutical regimens that merit further attention for their potential impact on alcohol-induced pathology. Measures which boost or preserve ALDH-2 activity may also have important antioxidant potential, as this enzyme functions physiologically to protect cells from toxic aldehydes generated by oxidant stress.
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Affiliation(s)
- Mark F McCarty
- NutriGuard Research, 1051 Hermes Ave., Encinitas, CA 92024, United States.
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152
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Hansen JM, Harris C. Redox control of teratogenesis. Reprod Toxicol 2013; 35:165-79. [DOI: 10.1016/j.reprotox.2012.09.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 09/17/2012] [Accepted: 09/20/2012] [Indexed: 01/19/2023]
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153
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Pillai VB, Sundaresan NR, Kim G, Samant S, Moreno-Vinasco L, Garcia JGN, Gupta MP. Nampt secreted from cardiomyocytes promotes development of cardiac hypertrophy and adverse ventricular remodeling. Am J Physiol Heart Circ Physiol 2012. [PMID: 23203961 DOI: 10.1152/ajpheart.00468.2012] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Nicotinamide phosphoribosyltransferase (Nampt) is an important coenzyme involved in cellular redox reactions. Inside the cell, Nampt (iNampt) functions as a rate-limiting enzyme in the NAD salvage pathway, and outside the cell (eNampt), it acts as a proinflammatory cytokine. High-circulating levels of Nampt are reported in different pathological conditions. This study was designed to examine the role of Nampt in the development of cardiac hypertrophy and ventricular remodeling. We studied the hypertrophic response in Nampt heterozygous (+/-) knockout and cardiac-specific overexpressing Nampt transgenic mice. Whereas Nampt(+/-) mice were protected against agonist (isoproterenol and angiotensin II)-induced hypertrophy, Nampt transgenic mice spontaneously developed cardiac hypertrophy at 6 mo of age. Experiments conducted to gain insight into the mechanism revealed that treatment of cardiomyocytes with recombinant (eNampt) or overexpression with Nampt-synthesizing adenovirus vector (Ad.Nampt) induced cardiomyocyte hypertrophy. The prohypertrophic effects of eNampt and Ad.Nampt were blocked by the addition of a Nampt-blocking antibody into cultures, thus suggesting that Nampt was in fact invoking hypertrophic response of cardiomyocytes by acting on the cell surface receptors. We also found increased Nampt levels in the supernatant of cardiomyocyte cultures subjected to stress by either serum starvation or H(2)O(2) treatment. Exploration of signaling pathways in Nampt-induced cardiac hypertrophy and fibrosis revealed increased activation of mitogen-activated protein kinases, namely, JNK1, p38, and ERK. This was also associated with increased calcineurin levels and nuclear factor of activated T-cell localization into the nucleus. From these studies we conclude that cardiomyocytes are capable of secreting Nampt during stress, and exogenous Nampt is a positive regulator of cardiac hypertrophy and adverse ventricular remodeling.
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Affiliation(s)
- Vinodkumar B Pillai
- Department of Surgery, Section of Cardiothoracic Surgery, University of Chicago, Chicago, Illinois 60637, USA
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154
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Locy ML, Rogers LK, Prigge JR, Schmidt EE, Arnér ESJ, Tipple TE. Thioredoxin reductase inhibition elicits Nrf2-mediated responses in Clara cells: implications for oxidant-induced lung injury. Antioxid Redox Signal 2012; 17:1407-16. [PMID: 22607006 PMCID: PMC3437047 DOI: 10.1089/ars.2011.4377] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
AIMS Pulmonary oxygen toxicity contributes to lung injury in newborn and adult humans. We previously reported that thioredoxin reductase (TrxR1) inhibition with aurothioglucose (ATG) attenuates hyperoxic lung injury in adult mice. The present studies tested the hypothesis that TrxR1 inhibition protects against the effects of hyperoxia via nuclear factor E2-related factor 2 (Nrf2)-dependent mechanisms. RESULTS Both pharmacologic and siRNA-mediated TrxR1 inhibition induced robust Nrf2 responses in murine-transformed Clara cells (mtCC). While TrxR1 inhibition did not alter the susceptibility of cells to the effects of hyperoxia, glutathione (GSH) depletion after TrxR1 inhibition markedly enhanced the hyperoxic susceptibility of cultured mtCCs. Finally, in vivo data revealed dose-dependent increases in the expression of the Nrf2 target gene NADPH:quinone oxidoreductase 1 (NQO1) in the lungs of ATG-treated adult mice. INNOVATION TrxR1 inhibition activates Nrf2-dependent antioxidant responses in mtCCs in vitro and in adult murine lungs in vivo, providing a plausible mechanism for the protective effects of TrxR1 inhibition in vivo. CONCLUSION GSH-dependent enzyme systems in mtCCs may be of greater importance for protection against hyperoxic exposure than are TrxR-dependent systems. The induction of Nrf2 activation via TrxR1 inhibition represents a novel therapeutic strategy that attenuates oxidant-mediated lung injury. Similar expression levels of TrxR1 in newborn and adult mouse or human lungs broaden the potential clinical applicability of the present findings to both neonatal and adult oxidant lung injury.
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Affiliation(s)
- Morgan L Locy
- Center for Perinatal Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
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155
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Glucose oxidase induces insulin resistance via influencing multiple targets in vitro and in vivo: The central role of oxidative stress. Biochimie 2012; 94:1705-17. [DOI: 10.1016/j.biochi.2012.03.024] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 03/29/2012] [Indexed: 01/11/2023]
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156
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Harris C, Hansen JM. Nrf2-mediated resistance to oxidant-induced redox disruption in embryos. ACTA ACUST UNITED AC 2012; 95:213-8. [PMID: 22495766 DOI: 10.1002/bdrb.21005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 01/19/2012] [Indexed: 12/20/2022]
Abstract
Events that control developmental changes occur during specific windows of gestation and if disrupted, can lead to dysmorphogenesis or embryolethality. One largely understudied aspect of developmental control is redox regulation, where the untimely disruption of intracellular redox potentials (E(h) ) may alter development, suggesting that tight control of developmental-stage-specific redox states is necessary to support normal development. In this study, mouse gestational day 8.5 embryos in whole embryo culture were treated with 10 μM dithiole-3-thione (D3T), an inducer of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). After 14 hr, D3T-treated and -untreated conceptuses were challenged with 200 μM hydrogen peroxide (H₂O₂) to induce oxidant-induced change to intracellular E(h) s. Redox potentials of glutathione (GSH), thioredoxin-1 (Trx1), and mitochondrial thioredoxin-2 (Trx2) were then measured over a 2-hr rebounding period following H₂O₂ treatment. D3T treatment increased embryonic expression of known Nrf2-regulated genes, including those responsible for redox regulation of major intracellular redox couples. Exposure to H₂O₂ without prior D3T treatment produced significant oxidation of GSH, Trx1, and Trx2, based on E(h) values, where GSH and Trx2 E(h) recovered, reaching to pre-H₂O₂ E(h) ranges, but Trx1 E(h) remained oxidized. Following H₂O₂ addition in culture to embryos that received D3T pretreatments, GSH, Trx1, and Trx2 were insulated from significant oxidation. These data show that Nrf2 activation may serve as a means to protect the embryo from chemically induced oxidative stress through the preservation of intracellular redox states during development, allowing normal morphogenesis to ensue.
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Affiliation(s)
- Craig Harris
- Developmental Toxicology Laboratory, Department of Environmental Health Sciences, University of Michigan, Ann Arbor, Michigan, USA
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157
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Wang X, Tao L, Hai CX. Redox-regulating role of insulin: the essence of insulin effect. Mol Cell Endocrinol 2012; 349:111-27. [PMID: 21878367 DOI: 10.1016/j.mce.2011.08.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 08/10/2011] [Accepted: 08/14/2011] [Indexed: 11/18/2022]
Abstract
It is well-known that insulin acts as an important hormone, controlling energy metabolism, cellular proliferation and biosynthesis of functional molecules to maintain a biological homeostasis. Over the past few years, intensive insulin therapy has been believed to be benefit for the outcome of diabetic patients, in which the suppression of oxidative stress plays a role. Moreover, insulin is accepted as a key component of glucose-insulin-potassium, a treatment which has been believed to exert significant cardiovascular protective effect via the reduction of oxidative stress. Furthermore, accumulating evidence has suggested that insulin exerts important redox-regulating actions in various insulin-sensitive target organs, implying the systematic antioxidative role of insulin as a hormone. It is time for us to revisit insulin effects, through summarizing and evaluating the novel functions of insulin and their mechanisms. This review focuses on the antioxidative effect of insulin and highlights insulin-induced regulation of various antioxidant enzymes via insulin signaling pathways and the cross talk between key transcription factors, including nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor κB (NF-κB) which are responsible for the transcription of antioxidant enzymes, leading to reduced generation of reactive oxygen species (ROS) and the enhancement of the elimination of ROS.
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Affiliation(s)
- Xin Wang
- Department of Toxicology, School of Preventive Medicine, The Fourth Military Medical University, Xi'an 710032, China
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158
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Feasibility of Medaka (Oryzias latipes) as an Animal Model to Study Fetal Alcohol Spectrum Disorder. ADVANCES IN MOLECULAR TOXICOLOGY VOLUME 6 2012. [DOI: 10.1016/b978-0-444-59389-4.00003-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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159
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Chen SY. Analysis of Nrf2-mediated transcriptional induction of antioxidant response in early embryos. Methods Mol Biol 2012; 889:277-290. [PMID: 22669671 DOI: 10.1007/978-1-61779-867-2_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Nrf2 is a transcription factor that regulates the induction of an expansive set of antioxidant proteins that act in synergy to remove reactive oxygen species (ROS). We have recently discovered that Nrf2 signaling is involved in the induction of antioxidant response in ethanol-exposed embryos. We have also demonstrated that chemically induced transcriptional activation of Nrf2 and subsequent induction of a broad spectrum of antioxidant proteins can act as an endogenous protective system against ethanol-induced oxidative stress and apoptosis in early mouse embryos. This chapter describes the methods used to analyze Nrf2-mediated transcriptional induction of antioxidant response in mouse embryos. Data which have been generated by using these methods have also been included to provide examples of their usefulness in evaluating Nrf2-mediated antioxidant response in early embryos.
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Affiliation(s)
- Shao-yu Chen
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria-UICOM-P, Peoria, IL, USA.
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160
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Narasimhan M, Mahimainathan L, Rathinam ML, Riar AK, Henderson GI. Overexpression of Nrf2 protects cerebral cortical neurons from ethanol-induced apoptotic death. Mol Pharmacol 2011; 80:988-99. [PMID: 21873460 DOI: 10.1124/mol.111.073262] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Ethanol (ETOH) can cause apoptotic death of neurons by depleting GSH with an associated increase in oxidative stress. The current study illustrates a means to overcome this ETOH-induced neurotoxicity by enhancing GSH through boosting Nrf2, a transcription factor that controls GSH homeostasis. ETOH treatment caused a significant increase in Nrf2 protein, transcript expression, Nrf2-DNA binding activity, and expression of its transcriptional target, NQO1, in primary cortical neuron (PCNs). However, this increase in Nrf2 did not maintain GSH levels in response to ETOH, and apoptotic death still occurred. To elucidate this phenomenon, we silenced Nrf2 in neurons and found that ETOH-induced GSH depletion and the increase in superoxide levels were exacerbated. Furthermore, Nrf2 knockdown resulted in significantly increased (P < 0.05) caspase 3 activity and apoptosis. Adenovirus-mediated overexpression of Nrf2 prevented ETOH-induced depletion of GSH from the medium and high GSH subpopulations and prevented ETOH-related apoptotic death. These studies illustrate the importance of Nrf2-dependent maintenance of GSH homeostasis in cerebral cortical neurons in the defense against oxidative stress and apoptotic death elicited by ETOH exposure.
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Affiliation(s)
- Madhusudhanan Narasimhan
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
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161
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Mehta AJ, Joshi PC, Fan X, Brown LAS, Ritzenthaler JD, Roman J, Guidot DM. Zinc supplementation restores PU.1 and Nrf2 nuclear binding in alveolar macrophages and improves redox balance and bacterial clearance in the lungs of alcohol-fed rats. Alcohol Clin Exp Res 2011; 35:1519-28. [PMID: 21447000 PMCID: PMC3128659 DOI: 10.1111/j.1530-0277.2011.01488.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Chronic alcohol abuse causes oxidative stress, impairs alveolar macrophage immune function, and increases the risk of pneumonia and acute lung injury. Recently we determined that chronic alcohol ingestion in rats decreases zinc levels and macrophage function in the alveolar space; provocative findings in that zinc is essential for normal immune and antioxidant defenses. Alveolar macrophage immune function depends on stimulation by granulocyte/monocyte colony-stimulating factor, which signals via the transcription factor PU.1. In parallel, the antioxidant response element signals via the transcription factor Nrf2. However, the role of zinc bioavailability on these signaling pathways within the alveolar space is unknown. METHODS To determine the efficacy of dietary zinc supplementation on lung bacterial clearance and oxidative stress, we tested 3 different groups of rats: control-fed, alcohol-fed, and alcohol-fed with zinc supplementation. Rats were then inoculated with intratracheal Klebsiella pneumoniae, and lung bacterial clearance was determined 24 hours later. Isolated alveolar macrophages were isolated from uninfected animals and evaluated for oxidative stress and signaling through PU.1 and Nrf2. RESULTS Alcohol-fed rats had a 5-fold decrease in lung bacterial clearance compared to control-fed rats. Dietary zinc supplementation of alcohol-fed rats normalized bacterial clearance and mitigated oxidative stress in the alveolar space, as reflected by the relative balance of the thiol redox pair cysteine and cystine, and increased nuclear binding of both PU.1 and Nrf2 in alveolar macrophages from alcohol-fed rats. CONCLUSIONS Dietary zinc supplementation prevents alcohol-induced alveolar macrophage immune dysfunction and oxidative stress in a relevant experimental model, suggesting that such a strategy could decrease the risk of pneumonia and lung injury in individuals with alcohol use disorders.
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Affiliation(s)
- Ashish J Mehta
- Atlanta VAMC, Emory University School of Medicine, Atlanta, GA 30033, USA.
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162
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Wang SK, Weaver JD, Zhang S, Lei XG. Knockout of SOD1 promotes conversion of selenocysteine to dehydroalanine in murine hepatic GPX1 protein. Free Radic Biol Med 2011; 51:197-204. [PMID: 21420488 PMCID: PMC3109192 DOI: 10.1016/j.freeradbiomed.2011.03.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 02/22/2011] [Accepted: 03/11/2011] [Indexed: 12/23/2022]
Abstract
Se-dependent glutathione peroxidase-1 (GPX1) and Cu,Zn-superoxide dismutase (SOD1) are two major intracellular antioxidant enzymes. The purpose of this study was to elucidate the biochemical mechanisms for the 40% loss of hepatic GPX1 activity in SOD1(-/-) mice. Compared with the wild type (WT), the SOD1(-/-) mice showed no change in the total amount of GPX1 protein. However, their total enzyme protein exhibited 31 and 38% decreases (P<0.05) in the apparent k(cat) for hydrogen peroxide and tert-butylperoxide (at 2mM GSH), respectively. Most striking, mass spectrometry revealed two chemical forms of the 47th residue of GPX1: the projected native selenocysteine (Sec) and the Se-lacking dehydroalanine (DHA). The hepatic GPX1 protein of the SOD1(-/-) mice contained 38% less Sec and 77% more DHA than that of WT and showed aggravated dissociation of the tetramer structure. In conclusion, knockout of SOD1 elevated the conversion of Sec to DHA in the active site of hepatic GPX1, leading to proportional decreases in the apparent k(cat) and activity of the enzyme protein as a whole. Our data reveal a structural and kinetic mechanism for the in vivo functional dependence of GPX1 on SOD1 in mammals and provide a novel mass spectrometric method for the assay of oxidative modification of the GPX1 protein.
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Affiliation(s)
- Shi Kui Wang
- Department of Animal Science, Cornell University, Ithaca, NY 14853, USA
| | - Jeremy D. Weaver
- Department of Animal Science, Cornell University, Ithaca, NY 14853, USA
| | - Sheng Zhang
- Department of Proteomics and Mass Spectrometry Core Facility, Cornell University, Ithaca, NY 14853, USA
| | - Xin Gen Lei
- Department of Animal Science, Cornell University, Ithaca, NY 14853, USA
- Contact information of the corresponding author: Dr. X. G. Lei, Professor, Department of Animal Science, Cornell University, Ithaca, NY 14853, USA, Tel: (607)-254-4703, Fax: (607)-255-9829,
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163
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Abstract
The developing brain is particularly vulnerable to reactive oxygen and reactive nitrogen species-mediated damage because of its high concentrations of unsaturated fatty acids, high rate of oxygen consumption, low concentrations of antioxidants, high content of metals catalyzing free radical formation, and large proportion of sensitive immature cells. In this review, we outline the dynamic changes of energy resources, metabolic requirements, and endogenous free radical scavenging systems during physiologic brain development. We further discuss the involvement of oxidative stress in the pathogenesis of neuronal death after exposure of the infant brain to hyperoxia, hypoxia/ischemia, sedative drugs, ethanol, and mechanical trauma. Several approaches have been developed to combat oxidative stress, but neuroprotective treatment strategies are limited in the clinical setting.
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Affiliation(s)
- Chrysanthy Ikonomidou
- Department of Neurology, University of Wisconsin, 600 Highland Avenue, Madison, WI 53792, USA.
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164
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Abstract
The ingestion of alcohol during pregnancy can result in a group of neurobehavioral abnormalities collectively known as fetal alcohol spectrum disorders (FASD). During the past decade, studies using animal models indicated that early alcohol exposure can dramatically affect neuronal plasticity, an essential property of the central nervous system responsible for the normal wiring of the brain and involved in processes such as learning and memory. The abnormalities in neuronal plasticity caused by alcohol can explain many of the neurobehavioral deficits observed in FASD. Conversely, improving neuronal plasticity may have important therapeutic benefits. In this review, the author discuss the mechanisms that lead to these abnormalities and comment on recent pharmacological approaches that have been showing promising results in improving neuronal plasticity in FASD.
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Affiliation(s)
- Alexandre E Medina
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0709, USA.
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165
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Dong J, Yan D, Chen SY. Stabilization of Nrf2 protein by D3T provides protection against ethanol-induced apoptosis in PC12 cells. PLoS One 2011; 6:e16845. [PMID: 21304811 PMCID: PMC3033411 DOI: 10.1371/journal.pone.0016845] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 01/06/2011] [Indexed: 12/03/2022] Open
Abstract
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.
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Affiliation(s)
- Jian Dong
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Dong Yan
- Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Shao-yu Chen
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine, Peoria, Illinois, United States of America
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166
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Wu M, Shariat-Madar B, Haron MH, Wu M, Khan IA, Dasmahapatra AK. Ethanol-induced attenuation of oxidative stress is unable to alter mRNA expression pattern of catalase, glutathione reductase, glutathione-S-transferase (GST1A), and superoxide dismutase (SOD3) enzymes in Japanese rice fish (Oryzias latipes) embryogenesis. Comp Biochem Physiol C Toxicol Pharmacol 2011; 153:159-67. [PMID: 20965276 PMCID: PMC2997190 DOI: 10.1016/j.cbpc.2010.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 10/08/2010] [Accepted: 10/10/2010] [Indexed: 10/18/2022]
Abstract
Although the mechanism of ethanol toxicity during embryogenesis is unknown, our earlier studies on Japanese rice fish (Oryzias latipes) embryos indicated that the effects might be mediated through oxidative stress. In this study we have determined the oxidative stress and the mRNA content of four antioxidant enzymes (catalase, glutathione reductase, glutathione-S-transferase, and superoxide dismutase) during Japanese rice fish embryogenesis (from 0 day post-fertilization to hatching) and after exposing the embryos to ethanol (100 and 300 mM) for 48 h at three stages (0-2, 1-3 and 4-6 days post-fertilization, dpf) of organogenesis. We observed that oxidative stress was minimal in blastula, gastrula or neurula stages, increased gradually with the advancement of morphogenesis and reached its maximum level in hatchlings. The antioxidant enzyme mRNAs were constitutively expressed throughout development; however, the expression pattern was not identical among the enzymes. Catalase and superoxide dismutase (SOD) mRNAs were minimal in the fertilized eggs, but increased significantly in 1 dpf and then either sharply dropped (SOD) or maintained a steady-state (catalase). Glutathione-S-transferase (GST) was very high in fertilized eggs and sharply dropped 1 dpf and then gradually increased thereafter. Glutathione reductase (GR) maintained a steady-state throughout the development. Ethanol was able to attenuate oxidative stress in embryos exposed only to 300 mM 1-3 dpf; no significant difference with controls was observed in other ethanol-treated groups. The antioxidant enzyme mRNAs also remained unaltered after ethanol treatment. From these data we conclude that the attenuation of oxidative stress by ethanol is probably due to the inhibition of normal growth of the embryos rather than by inhibiting catalase, GST, GR or SOD-dependent activities.
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Affiliation(s)
- Minghui Wu
- National Center for Natural Product Research, University of Mississippi, USA
- Department of Pharmacology, School of Pharmacy, University of Mississippi, USA
| | | | - Mona H. Haron
- National Center for Natural Product Research, University of Mississippi, USA
- Department of Pharmacology, School of Pharmacy, University of Mississippi, USA
| | - Mengmeng Wu
- Department of Pharmacology, School of Pharmacy, University of Mississippi, USA
| | - Ikhlas A. Khan
- National Center for Natural Product Research, University of Mississippi, USA
- Environmental Toxicology Research Program, University of Mississippi, USA
| | - Asok K. Dasmahapatra
- National Center for Natural Product Research, University of Mississippi, USA
- Environmental Toxicology Research Program, University of Mississippi, USA
- Department of Pharmacology, School of Pharmacy, University of Mississippi, USA
- Corresponding Author: Asok Dasmahapatra, National Center for Natural Product Research, School of Pharmacy, University of Mississippi, University, MS 38677, USA, Phone: 662-9157077; Fax: 662-9155148,
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167
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Idrus NM, Thomas JD. Fetal alcohol spectrum disorders: experimental treatments and strategies for intervention. ALCOHOL RESEARCH & HEALTH : THE JOURNAL OF THE NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM 2011; 34:76-85. [PMID: 23580044 PMCID: PMC3831616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/30/2022]
Abstract
Despite the known damaging effects of prenatal alcohol exposure, women continue to drink during pregnancy, creating a need for effective interventions and treatments for fetal alcohol spectrum disorders (FASD). Experimental models can be useful in identifying potential treatments, and this article describes the spectrum of experimental therapeutics that currently are being investigated, including pharmacological, nutritional, and environmental/behavioral interventions. Some treatments target the underlying mechanisms that contribute to alcohol-induced damage, protecting against alcohol's teratogenic effects, whereas other treatments may enhance central nervous system plasticity either during alcohol exposure or long after alcohol exposure has ceased. The insights gained to date from experimental models offer several candidates for attenuating the deficits associated with FASD.
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168
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Wilson SE, Cudd TA. Focus on: the use of animal models for the study of fetal alcohol spectrum disorders. ALCOHOL RESEARCH & HEALTH : THE JOURNAL OF THE NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM 2011; 34:92-8. [PMID: 23580046 PMCID: PMC3625987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Considerable efforts to educate women not to abuse alcohol during pregnancy have failed to reduce the incidence of fetal alcohol syndrome. Therefore, other approaches to limit the effects of prenatal alcohol exposure are under consideration, including the development of prevention programs and interventions. For these strategies to be as successful as possible, it also is important to improve methods for identifying affected children. The use of animal models in prenatal alcohol exposure research is critical because of the practical and ethical limitations of using human subjects for such studies. This article reviews the use of animal models in three areas of research: addressing basic questions about alcohol exposure during development; improving the identification of affected individuals; and developing approaches to reduce the impact of prenatal alcohol exposure. The various animal-model systems that have been used to study fetal alcohol spectrum disorders, each with their own specific strengths, have provided new findings that have been successfully extrapolated to human subjects, resulting in advancement of the research field and our understanding of fetal alcohol spectrum disorders.
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Affiliation(s)
- Shannon E Wilson
- College of Veterinary Medicine and Biomedical Sciences, Texas A and M University, College Station, Texas
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169
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Parnell SE, Sulik KK, Dehart DB, Chen SY. Reduction of ethanol-induced ocular abnormalities in mice through dietary administration of N-acetylcysteine. Alcohol 2010; 44:699-705. [PMID: 21112471 DOI: 10.1016/j.alcohol.2010.05.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 05/07/2010] [Accepted: 05/12/2010] [Indexed: 02/05/2023]
Abstract
N-acetylcysteine (NAC) is a derivative of the amino acid l-cysteine, which, previously, has been shown to protect against ethanol-induced apoptosis during early development. Ongoing research demonstrates that NAC is also proving clinically beneficial in reducing oxidative stress-mediated lung, liver, and kidney damage, with protection likely resulting from a NAC-mediated increase in glutathione levels. In the present study, the hypothesis that coadministration of NAC and ethanol by means of liquid diet on days 7 and 8 of pregnancy in mice would reduce ethanol's teratogenicity was tested. For this work, adult nonpregnant female mice were acclimated to a liquid diet containing ethanol for 16 days, withdrawn from the ethanol, bred, and then returned to the liquid diet containing 4.8% ethanol and/or either 0.5 or 1-mg NAC/mL diet on their seventh and eighth days of pregnancy. At the concentrations used, the mice received NAC dosages of approximately 300 or 600 mg/kg/day and achieved peak blood ethanol concentrations (BEC) that averaged approximately 200mg/dL. There was no difference in BEC between the ethanol-alone and ethanol plus 600 mg/kg NAC group. After maternal euthanasia, gestational day (GD) 14 fetuses were removed, fixed, weighed, and examined for the presence and severity of ocular abnormalities, a readily assessed endpoint that results from GD 7 and 8 ethanol exposures. Although the lower dosage of NAC (300 mg/kg) resulted in a decrease in the incidence of ocular defects in both the left and right eyes, this reduction was not statistically significant. However, doubling the NAC concentration did yield a significant change; as compared with the group treated with ethanol alone, the incidence of ocular abnormalities was diminished by 22%. These results show the potential of an orally administered compound with proven clinical efficacy to reduce ethanol's teratogenic effects and support the premise that oxidative damage plays an important mechanistic role in fetal alcohol spectrum disorders.
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Affiliation(s)
- Scott E Parnell
- Bowles Center for Alcohol Studies and Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
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170
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Yan D, Dong J, Sulik KK, Chen SY. Induction of the Nrf2-driven antioxidant response by tert-butylhydroquinone prevents ethanol-induced apoptosis in cranial neural crest cells. Biochem Pharmacol 2010; 80:144-9. [PMID: 20223225 PMCID: PMC2860686 DOI: 10.1016/j.bcp.2010.03.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 03/02/2010] [Accepted: 03/02/2010] [Indexed: 11/23/2022]
Abstract
Previous studies have shown that ethanol exposure causes apoptosis in cranial neural crest cells (NCCs), an ethanol-sensitive cell population implicated in Fetal Alcohol Spectrum Disorders (FASD). Additionally, induction of endogenous antioxidants through activation of nuclear factor-erythroid 2-related factor 2 (Nrf2) has been shown to prevent oxidative stress and apoptosis in ethanol-exposed mouse embryos. The objective of this study was to test whether tert-butylhydroquinone (tBHQ), an Nrf2 inducer, can protect NCCs against ethanol-induced apoptosis. Ethanol exposure was shown to cause a moderate increase in the protein expression of Nrf2 and its downstream antioxidants in the NCCs. Treatment of NCCs with tBHQ alone significantly increased the protein expression of Nrf2 and its downstream antioxidants and also significantly increased the activities of the antioxidant enzymes. In NCCs exposed to ethanol, the tBHQ-mediated antioxidant response prevented oxidative stress and apoptosis. These results clearly demonstrate that the activation of Nrf2 signaling confers protection against ethanol-induced apoptosis in NCCs.
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Affiliation(s)
- Dong Yan
- Bowles Center for Alcohol Studies & Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Jian Dong
- Bowles Center for Alcohol Studies & Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kathleen K. Sulik
- Bowles Center for Alcohol Studies & Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Shao-yu Chen
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine, Peoria, IL 61656, USA
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171
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Alexander PG, Tuan RS. Role of environmental factors in axial skeletal dysmorphogenesis. ACTA ACUST UNITED AC 2010; 90:118-32. [DOI: 10.1002/bdrc.20179] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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172
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Abstract
Oxidative stress and matrix metalloproteinases (MMPs) contribute to hemorrhagic transformation after ischemic stroke and brain injury after intracerebral hemorrhage (ICH). The goal of this study was to develop a new model of spontaneous ICH, based on the hypothesis that acute, superimposed on chronic, hypertension produces ICH. We hypothesized that increases in angiotensin II (AngII)-mediated oxidative stress and activation of MMPs are associated with, and may precede, spontaneous ICH during hypertension. In C57BL/6 mice, chronic hypertension was produced with AngII infusion and an inhibitor of nitric oxide synthase. During chronic hypertension, mice with acute hypertension from injections of AngII developed ICH. Oxidative stress and MMP levels increased in the brain even before developing ICH. Active MMPs colocalized with a marker of oxidative stress, especially on cerebral vessels that appeared to lead toward regions with ICH. Incidence of ICH and levels of oxidative stress and MMP-9 were greater in mice with acute hypertension produced by AngII than by norepinephrine. In summary, we have developed an experimental model of ICH during hypertension that may facilitate studies in genetically altered mice. We speculate that acute hypertension, especially when induced by AngII, may be critical in spontaneous ICH during chronic hypertension, possibly through oxidative stress and MMP-9.
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173
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The role of NOX enzymes in ethanol-induced oxidative stress and apoptosis in mouse embryos. Toxicol Lett 2009; 193:94-100. [PMID: 20026259 DOI: 10.1016/j.toxlet.2009.12.012] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 12/10/2009] [Accepted: 12/11/2009] [Indexed: 01/21/2023]
Abstract
Reactive oxygen species (ROS) play an important role in ethanol-induced apoptosis and teratogenesis. However, the major sources of ROS in ethanol-exposed embryos have remained undefined. This study was conducted to determine the role of NADPH oxidase (NOX) in ethanol-induced oxidative stress and apoptosis in mouse embryos. Analyses of mRNA expression indicated that ethanol treatment resulted in a significant increase in mRNA expression of NOX catalytic subunit Duox-1 in gestational day 9 (GD 9:0) mouse embryos. Ethanol exposure also resulted in significant increases in mRNA expression of NOX regulatory subunits, p22phox, p67phox, NOXA1 and NOXO1. In addition, a significant increase in NOX enzyme activity was found in the ethanol-exposed embryos as compared to controls. Co-treatment with the NOX inhibitor, diphenyleneiodonium (DPI), significantly prevented ethanol-induced increases in NOX enzyme activity, ROS generation and oxidative DNA damage in ethanol-exposed embryos. DPI treatment also resulted in a reduction in caspase-3 activation, decreased caspase-3 activity and diminished prevalence of apoptosis in ethanol-exposed embryos. These results support the hypothesis that NOX is a critical source of ROS in ethanol-exposed embryos and that it plays an important role in ethanol-induced oxidative stress and pathogenesis.
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174
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Altered gene expression in neural crest cells exposed to ethanol in vitro. Brain Res 2009; 1305 Suppl:S50-60. [DOI: 10.1016/j.brainres.2009.08.057] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 07/07/2009] [Accepted: 08/06/2009] [Indexed: 11/19/2022]
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175
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Pillai VB, Sundaresan NR, Kim G, Gupta M, Rajamohan SB, Pillai JB, Samant S, Ravindra PV, Isbatan A, Gupta MP. Exogenous NAD blocks cardiac hypertrophic response via activation of the SIRT3-LKB1-AMP-activated kinase pathway. J Biol Chem 2009; 285:3133-44. [PMID: 19940131 DOI: 10.1074/jbc.m109.077271] [Citation(s) in RCA: 319] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Since the discovery of NAD-dependent deacetylases, sirtuins, it has been recognized that maintaining intracellular levels of NAD is crucial for the management of stress response of cells. Here we show that agonist-induced cardiac hypertrophy is associated with loss of intracellular levels of NAD, but not exercise-induced physiologic hypertrophy. Exogenous addition of NAD was capable of maintaining intracellular levels of NAD and blocking the agonist-induced cardiac hypertrophic response in vitro as well as in vivo. NAD treatment blocked the activation of pro-hypertrophic Akt1 signaling, and augmented the activity of anti-hypertrophic LKB1-AMPK signaling in the heart, which prevented subsequent induction of mTOR-mediated protein synthesis. By using gene knock-out and transgenic mouse models of SIRT3 and SIRT1, we showed that the anti-hypertrophic effects of exogenous NAD are mediated through activation of SIRT3, but not SIRT1. SIRT3 deacetylates and activates LKB1, thus augmenting the activity of the LKB1-AMPK pathway. These results reveal a novel role of NAD as an inhibitor of cardiac hypertrophic signaling, and suggest that prevention of NAD depletion may be critical in the treatment of cardiac hypertrophy and heart failure.
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176
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Cederbaum A. Nrf2 and antioxidant defense against CYP2E1 toxicity. Expert Opin Drug Metab Toxicol 2009; 5:1223-44. [PMID: 19671018 DOI: 10.1517/17425250903143769] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The transcription factor Nrf2 regulates the expression of important cytoprotective enzymes. Induction of CYP2E1 is one of the central pathways by which ethanol generates oxidative stress. CYP2E1 can be induced by ethanol and several low molecular mass chemicals such as pyrazole. This review discusses biochemical and toxicological effects of CYP2E1 and the effects of Nrf2 in modulating these actions of CYP2E1. Besides ethanol, CYP2E1 metabolizes and activates many other toxicologic important compounds. One approach to try to understand the basic effects and actions of CYP2E1 was to establish HepG2 cell lines that constitutively express human CYP2E1. Ethanol, polyunsaturated fatty acids and iron were toxic to the HepG2 cells, which express CYP2E1 (E47 cells) but not control C34HepG2 cells, which do not express CYP2E1. Toxicity was associated with enhanced oxidant stress and could be prevented by antioxidants and potentiated if glutathione was removed. The E47 cells had higher glutathione levels and a twofold increase in catalase, cytosolic and microsomal glutathione transferase, and heme oxygenase-1 than control HepG2 cells due to activation of their respective genes. These activations were prevented by antioxidants, suggesting that reactive oxygen species generated by CYP2E1 were responsible for the upregulation of these antioxidant genes. This upregulation may reflect an adaptive mechanism to remove CYP2E1-derived oxidants. Increases in Nrf2 protein and mRNA were observed in livers of chronic alcohol-fed mice or rats and of pyrzole-treated rats or mice, conditions known to elevate CYP2E1. E47 cells showed increased Nrf2 mRNA and protein expression compared with control HepG2 C34 cells. Upregulation of antioxidant genes in E47 cells is dependent on Nrf2 and is prevented by siRNA-Nrf2. Blocking Nrf2 by siRNA-Nrf2 decreases glutathione and increases reactive oxygen species and lipid peroxidation, resulting in decreased mitochondrial membrane potential and loss of cell viability of E47 cells, but not C34 cells. Nrf2 is activated and levels of Nrf2 protein and mRNA are increased when CYP2E1 is elevated. These results suggest that Nrf2 plays a key role in the adaptive response against increased oxidative stress caused by CYP2E1 in the HepG2 cells. However, it is not clear whether Nrf2 is protective against CYP2E1 toxicity in vivo as pyrazole which elevates CYP2E1 in wild-type mice did not elevate CYP2E1 in Nrf2 knockout mice, although pyrazole produced toxicity in the Nrf2 knockout mice.
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Affiliation(s)
- Arthur Cederbaum
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, Box 1603, One Gustave L Levy Place, New York, NY 10029, USA.
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177
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Sundaresan NR, Gupta M, Kim G, Rajamohan SB, Isbatan A, Gupta MP. Sirt3 blocks the cardiac hypertrophic response by augmenting Foxo3a-dependent antioxidant defense mechanisms in mice. J Clin Invest 2009; 119:2758-71. [PMID: 19652361 DOI: 10.1172/jci39162] [Citation(s) in RCA: 504] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Accepted: 06/03/2009] [Indexed: 01/11/2023] Open
Abstract
Sirtuin 3 (SIRT3) is a member of the sirtuin family of proteins that promote longevity in many organisms. Increased expression of SIRT3 has been linked to an extended life span in humans. Here, we have shown that Sirt3 protects the mouse heart by blocking the cardiac hypertrophic response. Although Sirt3-deficient mice appeared to have normal activity, they showed signs of cardiac hypertrophy and interstitial fibrosis at 8 weeks of age. Application of hypertrophic stimuli to these mice produced a severe cardiac hypertrophic response, whereas Sirt3-expressing Tg mice were protected from similar stimuli. In primary cultures of cardiomyocytes, Sirt3 blocked cardiac hypertrophy by activating the forkhead box O3a-dependent (Foxo3a-dependent), antioxidant-encoding genes manganese superoxide dismutase (MnSOD) and catalase (Cat), thereby decreasing cellular levels of ROS. Reduced ROS levels suppressed Ras activation and downstream signaling through the MAPK/ERK and PI3K/Akt pathways. This resulted in repressed activity of transcription factors, specifically GATA4 and NFAT, and translation factors, specifically eukaryotic initiation factor 4E (elf4E) and S6 ribosomal protein (S6P), which are involved in the development of cardiac hypertrophy. These results demonstrate that SIRT3 is an endogenous negative regulator of cardiac hypertrophy, which protects hearts by suppressing cellular levels of ROS.
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