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Zheng H, Xu Y, Liehn EA, Rusu M. Vitamin C as Scavenger of Reactive Oxygen Species during Healing after Myocardial Infarction. Int J Mol Sci 2024; 25:3114. [PMID: 38542087 PMCID: PMC10970003 DOI: 10.3390/ijms25063114] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/31/2024] [Accepted: 02/10/2024] [Indexed: 06/26/2024] Open
Abstract
Currently, coronary artery bypass and reperfusion therapies are considered the gold standard in long-term treatments to restore heart function after acute myocardial infarction. As a drawback of these restoring strategies, reperfusion after an ischemic insult and sudden oxygen exposure lead to the exacerbated synthesis of additional reactive oxidative species and the persistence of increased oxidation levels. Attempts based on antioxidant treatment have failed to achieve an effective therapy for cardiovascular disease patients. The controversial use of vitamin C as an antioxidant in clinical practice is comprehensively systematized and discussed in this review. The dose-dependent adsorption and release kinetics mechanism of vitamin C is complex; however, this review may provide a holistic perspective on its potential as a preventive supplement and/or for combined precise and targeted therapeutics in cardiovascular management therapy.
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Affiliation(s)
- Huabo Zheng
- Department of Cardiology, Angiology and Intensive Care, University Hospital, Rheinisch-Westfälische Technische Hochschule Aachen University, 52074 Aachen, Germany;
- Institute of Molecular Medicine, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark;
| | - Yichen Xu
- Institute of Molecular Medicine, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark;
- Department of Histology and Embryology, Medicine and Life Sciences, Hainan Medical University, Haikou 571199, China
| | - Elisa A. Liehn
- Institute of Molecular Medicine, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark;
- National Institute of Pathology “Victor Babes”, Splaiul Independentei Nr. 99-101, 050096 Bucharest, Romania
| | - Mihaela Rusu
- Institute of Applied Medical Engineering, Helmholtz Institute, Medical Faculty, Rheinisch-Westfälische Technische Hochschule Aachen University, 52074 Aachen, Germany
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Praditi C, Bozonet SM, Dachs GU, Vissers MCM. Ascorbate Uptake and Retention by Breast Cancer Cell Lines and the Intracellular Distribution of Sodium-Dependent Vitamin C Transporter 2. Antioxidants (Basel) 2023; 12:1929. [PMID: 38001782 PMCID: PMC10669237 DOI: 10.3390/antiox12111929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/26/2023] [Accepted: 10/26/2023] [Indexed: 11/26/2023] Open
Abstract
Ascorbate plays a vital role as a co-factor for a superfamily of enzymes, the 2-oxoglutarate dependent dioxygenases (2-OGDDs), which govern numerous pathways in cancer progression, including the hypoxic response and the epigenetic regulation of gene transcription. Ascorbate uptake into most cells is through active transport by the sodium-dependent vitamin C transporter 2 (SVCT2). The aims of this study were to determine the kinetics of ascorbate uptake and retention by breast cancer cell lines under various oxygen conditions, and to investigate the role of SVCT2 in mediating ascorbate uptake and intracellular trafficking. Human MDA-MB231 cells accumulated up to 5.1 nmol ascorbate/106 cells, human MCF7 cells 4.5 nmol/106 cells, and murine EO771 cells 26.7 nmol/106 cells. Intracellular ascorbate concentrations decreased rapidly after reaching maximum levels unless further ascorbate was supplied to the medium, and there was no difference in the rate of ascorbate loss under normoxia or hypoxia. SVCT2 was localised mainly to subcellular compartments, with the nucleus apparently containing the most SVCT2 protein, followed by the mitochondria. Much less SVCT2 staining was observed on the plasma membrane. Our data showed that careful management of the doses and incubation times with ascorbate in vitro allows for an approximation of in vivo conditions. The localisation of SVCT2 suggests that the distribution of ascorbate to intracellular compartments is closely aligned to the known function of ascorbate in supporting 2-OGDD enzymatic functions in the organelles and with supporting antioxidant protection in the mitochondria.
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Affiliation(s)
- Citra Praditi
- Mātai Hāora—Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand; (C.P.); (S.M.B.)
| | - Stephanie M. Bozonet
- Mātai Hāora—Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand; (C.P.); (S.M.B.)
| | - Gabi U. Dachs
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand;
| | - Margreet C. M. Vissers
- Mātai Hāora—Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand; (C.P.); (S.M.B.)
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3
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Mikkelsen SU, Gillberg L, Lykkesfeldt J, Grønbæk K. The role of vitamin C in epigenetic cancer therapy. Free Radic Biol Med 2021; 170:179-193. [PMID: 33789122 DOI: 10.1016/j.freeradbiomed.2021.03.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 12/27/2022]
Abstract
The role of vitamin C in the treatment of cancer has been subject to controversy for decades. Within the past 10 years, mechanistic insight into the importance of vitamin C in epigenetic regulation has provided a new rationale for its potential anti-cancer effects. At physiological concentrations, vitamin C is a potent antioxidant and thereby co-factor for a range of enzymes including the Fe(II)- and α-ketoglutarate-dependent dioxygenases that represent some of the most important epigenetic regulators; the ten-eleven translocation (TET) methylcytosine dioxygenases and the Jumonji-C domain-containing histone demethylases. Epigenetic deregulation is a hallmark of many cancers and reduced activity of these enzymes or somatic loss-of-function mutations in the genes encoding them, are observed in many cancer types. The present review outlines the growing literature on the role of vitamin C in epigenetic therapy of cancer. In the vast majority of in vitro, animal and clinical studies included in this review, vitamin C showed ability across cancer types to increase the hydroxylation of 5-methylcytosine to 5-hydroxymethylcytosine catalyzed by the TET enzymes - the first step in DNA demethylation. Most consistently, vitamin C in combination with the class of epigenetic drugs, DNA methyltransferase inhibitors, has demonstrated efficacy in the treatment of hematological malignancies in both preclinical and the limited number of available clinical studies. Yet, the pertinent question of what is the optimal dose of vitamin C in cancer studies remains to be answered. High-quality randomized placebo-controlled trials are needed to determine whether supplementation with vitamin C may benefit subgroups of patients with (pre-)cancer.
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Affiliation(s)
- Stine Ulrik Mikkelsen
- Department of Hematology, Rigshospitalet, Juliane Maries Vej 10, 2100, Copenhagen, Denmark; Biotech Research and Innovation Centre (BRIC), Department of Health and Medical Sciences, University of Copenhagen, Ole Maaløes Vej 5, Building 2, 3rd Floor, 2200, Copenhagen, Denmark
| | - Linn Gillberg
- Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Jens Lykkesfeldt
- Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1st Floor, 1870, Frederiksberg, Denmark
| | - Kirsten Grønbæk
- Department of Hematology, Rigshospitalet, Juliane Maries Vej 10, 2100, Copenhagen, Denmark; Biotech Research and Innovation Centre (BRIC), Department of Health and Medical Sciences, University of Copenhagen, Ole Maaløes Vej 5, Building 2, 3rd Floor, 2200, Copenhagen, Denmark; DanStem, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
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Vitamin C Deficiency Inhibits Nonalcoholic Fatty Liver Disease Progression through Impaired de Novo Lipogenesis. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:1550-1563. [PMID: 34126083 DOI: 10.1016/j.ajpath.2021.05.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/09/2021] [Accepted: 05/20/2021] [Indexed: 12/17/2022]
Abstract
Despite the increasing clinical importance of nonalcoholic fatty liver disease (NAFLD), little is known about its underlying pathogenesis or specific treatment. The senescence marker protein 30 (SMP30), which regulates the biosynthesis of vitamin C (VC) in many mammals, except primates and humans, was recently recognized as a gluconolactonase. However, the precise relation between VC and lipid metabolism in NAFLD is not completely understood. Therefore, this study aimed to clearly reveal the role of VC in NAFLD progression. SMP30 knockout (KO) mice were used as a VC-deficient mouse model. To investigate the precise role of VC on lipid metabolism, 13- to 15-week-old SMP30 KO mice and wild-type mice fed a 60% high-fat diet were exposed to tap water or VC-containing water (1.5 g/L) ad libitum for 11 weeks. Primary mouse hepatocytes isolated from the SMP30 KO and wild-type mice were used to demonstrate the relation between VC and lipid metabolism in hepatocytes. Long-term VC deficiency significantly suppressed the progression of simple steatosis. The high-fat diet-fed VC-deficient SMP30 KO mice exhibited impaired sterol regulatory element-binding protein-1c activation because of excessive cholesterol accumulation in hepatocytes. Long-term VC deficiency inhibits de novo lipogenesis through impaired sterol regulatory element-binding protein-1c activation.
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Gonzalez-Menendez P, Romano M, Yan H, Deshmukh R, Papoin J, Oburoglu L, Daumur M, Dumé AS, Phadke I, Mongellaz C, Qu X, Bories PN, Fontenay M, An X, Dardalhon V, Sitbon M, Zimmermann VS, Gallagher PG, Tardito S, Blanc L, Mohandas N, Taylor N, Kinet S. An IDH1-vitamin C crosstalk drives human erythroid development by inhibiting pro-oxidant mitochondrial metabolism. Cell Rep 2021; 34:108723. [PMID: 33535038 PMCID: PMC9169698 DOI: 10.1016/j.celrep.2021.108723] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 11/26/2020] [Accepted: 01/12/2021] [Indexed: 12/12/2022] Open
Abstract
The metabolic changes controlling the stepwise differentiation of hematopoietic stem and progenitor cells (HSPCs) to mature erythrocytes are poorly understood. Here, we show that HSPC development to an erythroid-committed proerythroblast results in augmented glutaminolysis, generating alpha-ketoglutarate (αKG) and driving mitochondrial oxidative phosphorylation (OXPHOS). However, sequential late-stage erythropoiesis is dependent on decreasing αKG-driven OXPHOS, and we find that isocitrate dehydrogenase 1 (IDH1) plays a central role in this process. IDH1 downregulation augments mitochondrial oxidation of αKG and inhibits reticulocyte generation. Furthermore, IDH1 knockdown results in the generation of multinucleated erythroblasts, a morphological abnormality characteristic of myelodysplastic syndrome and congenital dyserythropoietic anemia. We identify vitamin C homeostasis as a critical regulator of ineffective erythropoiesis; oxidized ascorbate increases mitochondrial superoxide and significantly exacerbates the abnormal erythroblast phenotype of IDH1-downregulated progenitors, whereas vitamin C, scavenging reactive oxygen species (ROS) and reprogramming mitochondrial metabolism, rescues erythropoiesis. Thus, an IDH1-vitamin C crosstalk controls terminal steps of human erythroid differentiation.
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Affiliation(s)
- Pedro Gonzalez-Menendez
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France.
| | - Manuela Romano
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France
| | - Hongxia Yan
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; New York Blood Center, New York, NY, USA
| | - Ruhi Deshmukh
- Cancer Research UK Beatson Institute, Glasgow G61 1BD, UK
| | - Julien Papoin
- The Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Leal Oburoglu
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France
| | - Marie Daumur
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France
| | - Anne-Sophie Dumé
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France
| | - Ira Phadke
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France; Pediatric Oncology Branch, NCI, CCR, NIH, Bethesda, MD, USA
| | - Cédric Mongellaz
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France
| | - Xiaoli Qu
- New York Blood Center, New York, NY, USA
| | - Phuong-Nhi Bories
- Service d'Hématologie Biologique, Assistance Publique-Hôpitaux de Paris, Institut Cochin, Paris, France
| | - Michaela Fontenay
- Laboratory of Excellence GR-Ex, Paris 75015, France; Service d'Hématologie Biologique, Assistance Publique-Hôpitaux de Paris, Institut Cochin, Paris, France
| | - Xiuli An
- New York Blood Center, New York, NY, USA
| | - Valérie Dardalhon
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France
| | - Marc Sitbon
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France
| | - Valérie S Zimmermann
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France
| | - Patrick G Gallagher
- Departments of Pediatrics and Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Saverio Tardito
- Cancer Research UK Beatson Institute, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Glasgow G61 1QH, UK
| | - Lionel Blanc
- The Feinstein Institute for Medical Research, Manhasset, NY, USA
| | | | - Naomi Taylor
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France; Pediatric Oncology Branch, NCI, CCR, NIH, Bethesda, MD, USA.
| | - Sandrina Kinet
- Institut de Génétique Moléculaire de Montpellier, Univ. Montpellier, CNRS, Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France.
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Goralska M, Fleisher LN, McGahan MC. Vitreous Humor Changes Expression of Iron-Handling Proteins in Lens Epithelial Cells. Invest Ophthalmol Vis Sci 2017; 58:1187-1195. [PMID: 28245299 PMCID: PMC5338632 DOI: 10.1167/iovs.16-20610] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose In humans, vitrectomy is associated with development of nuclear cataracts. Iron catalyzes free radical formation causing oxidative damage, which is implicated in cataract formation. This study was designed to determine if vitreous humor, which can initiate differentiation of lens epithelial cells, would have an effect on iron-handling proteins. Methods Cultured canine lens epithelial cells were treated with collected canine vitreous humor. Lysates of treated and control cells were separated by SDS-PAGE. Ferritin H- and L-chains, transferrin receptor 1, and aquaporin 0 were immunodetected and quantitated with specific antibodies. Morphologic changes in treated cells were assessed. Results Treatment of lens epithelial cells with a 33% (vol/vol) solution of vitreous humor changed the morphology of lens cells and induced expression of aquaporin 0, a marker of fiber cell differentiation that was undetectable in control cells. Treatment did not modify the size of iron-handling proteins but significantly increased content of ferritin from 2.9- to 8.8-fold over control and decreased levels of transferrin receptor by 37% to 59%. Conclusions Vitreous humor may significantly limit iron uptake by transferrin/transferrin receptor pathway, and by increasing ferritin levels could profoundly increase the iron-storage capacity of ferritin in lens cells. Vitreous humor may play a significant protective role against iron-catalyzed oxidative damage of lens epithelial cells and therefore in the formation of cataracts.
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Affiliation(s)
- Malgorzata Goralska
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, North Carolina, United States
| | - Lloyd N Fleisher
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, North Carolina, United States
| | - M Christine McGahan
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, North Carolina, United States
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Ascorbic acid, but not dehydroascorbic acid increases intracellular vitamin C content to decrease Hypoxia Inducible Factor -1 alpha activity and reduce malignant potential in human melanoma. Biomed Pharmacother 2016; 86:502-513. [PMID: 28012930 DOI: 10.1016/j.biopha.2016.12.056] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 12/09/2016] [Accepted: 12/14/2016] [Indexed: 12/13/2022] Open
Abstract
INTRODUCTION Accumulation of hypoxia inducible factor-1 alpha (HIF-1α) in malignant tissue is known to contribute to oncogenic progression and is inversely associated with patient survival. Ascorbic acid (AA) depletion in malignant tissue may contribute to aberrant normoxic activity of HIF-1α. While AA supplementation has been shown to attenuate HIF-1α function in malignant melanoma, the use of dehydroascorbic acid (DHA) as a therapeutic means to increase intracellular AA and modulate HIF-1α function is yet to be evaluated. Here we compared the ability of AA and DHA to increase intracellular vitamin C content and decrease the malignant potential of human melanoma by reducing the activity of HIF-1α. METHODS HIF-1α protein accumulation was evaluated by western blot and transcriptional activity was evaluated by reporter gene assay using a HIF-1 HRE-luciferase plasmid. Protein expressions and subcellular localizations of vitamin C transporters were evaluated by western blot and confocal imaging. Intracellular vitamin C content following AA, ascorbate 2-phosphate (A2P), or DHA supplementation was determined using a vitamin C assay. Malignant potential was accessed using a 3D spheroid Matrigel invasion assay. Data was analyzed by One or Two-way ANOVA with Tukey's multiple comparisons test as appropriate with p<0.05 considered significant. RESULTS Melanoma cells expressed both sodium dependent vitamin C (SVCT) and glucose (GLUT) transporters for AA and DHA transport respectively, however advanced melanomas responded favorably to AA, but not DHA. Physiological glucose conditions significantly impaired intracellular vitamin C accumulation following DHA treatment. Consequently, A2P and AA, but not DHA treated cells demonstrated lower HIF-1α protein expression and activity, and reduced malignant potential. The ability of AA to regulate HIF-1α was dependent on SVCT2 function and SVCT2 was not significantly inhibited at pH representative of the tumor microenvironment. CONCLUSIONS The use of ascorbic acid as an adjuvant cancer therapy remains under investigated. While AA and A2P were capable of modulating HIF-1α protein accumulation/activity, DHA supplementation resulted in minimal intracellular vitamin C activity with decreased ability to inhibit HIF-1α activity and malignant potential in advanced melanoma. Restoring AA dependent regulation of HIF-1α in malignant cells may prove beneficial in reducing chemotherapy resistance and improving treatment outcomes.
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A reactivity-based probe of the intracellular labile ferrous iron pool. Nat Chem Biol 2016; 12:680-5. [PMID: 27376690 PMCID: PMC4990480 DOI: 10.1038/nchembio.2116] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 04/12/2016] [Indexed: 12/14/2022]
Abstract
Improved methods for studying intracellular reactive iron(II) are of significant interest for studies of iron metabolism and disease relevant changes in iron homeostasis. Here we describe a highly-selective reactivity-based probe in which Fenton-type reaction with intracellular labile iron(II) leads to unmasking of the aminonucleoside puromycin. Puromycin leaves a permanent and dose-dependent mark on treated cells that can be detected with high sensitivity and precision using the high-content, plate-based immunofluorescence assay described. Using this new probe and screening approach, we detected alteration of cellular labile iron(II) in response extracellular iron conditioning, overexpression of iron storage and/or export proteins, and post-translational regulation of iron export. Finally, we utilized this new tool to demonstrate the presence of augmented labile iron(II) pools in cancer cells as compared to non-tumorigenic cells.
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Abstract
The prognosis for patients diagnosed with pancreatic cancer remains dismal, with less than 3% survival at 5 years. Recent studies have demonstrated that high-dose, intravenous pharmacological ascorbate (ascorbic acid, vitamin C) induces cytotoxicity and oxidative stress selectively in pancreatic cancer cells vs. normal cells, suggesting a promising new role of ascorbate as a therapeutic agent. At physiologic concentrations, ascorbate functions as a reducing agent and antioxidant. However, when pharmacological ascorbate is given intravenously, it is possible to achieve millimolar plasma concentration. At these pharmacological levels, and in the presence of catalytic metal ions, ascorbate can induce oxidative stress through the generation of hydrogen peroxide (H2O2). Recent in vitro and in vivo studies have demonstrated ascorbate oxidation occurs extracellularly, generating H2O2 flux into cells resulting in oxidative stress. Pharmacologic ascorbate also inhibits the growth of pancreatic tumor xenografts and displays synergistic cytotoxic effects when combined with gemcitabine in pancreatic cancer. Phase I trials of pharmacological ascorbate in pancreatic cancer patients have demonstrated safety and potential efficacy. In this chapter, we will review the mechanism of ascorbate-induced cytotoxicity, examine the use of pharmacological ascorbate in treatment and assess the current data supporting its potential as an adjuvant in pancreatic cancer.
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Affiliation(s)
| | - Joseph J Cullen
- 1528 JCP, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA.
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10
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Wang TY, Sun Y, Muthukrishnan N, Erazo-Oliveras A, Najjar K, Pellois JP. Membrane Oxidation Enables the Cytosolic Entry of Polyarginine Cell-penetrating Peptides. J Biol Chem 2016; 291:7902-14. [PMID: 26888085 DOI: 10.1074/jbc.m115.711564] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Indexed: 12/29/2022] Open
Abstract
Arginine-rich peptides can penetrate cells and consequently be used as delivery agents in various cellular applications. The activity of these reagents is often context-dependent, and the parameters that impact cell entry are not fully understood, giving rise to variability and limiting progress toward their usage. Herein, we report that the cytosolic penetration of linear polyarginine peptides is dependent on the oxidation state of the cell. In particular, we find that hypoxia and cellular antioxidants inhibit cell penetration. In contrast, oxidants promote cytosolic cell entry with an efficiency proportional to the level of reactive oxygen species generated within membranes. Moreover, an antibody that binds to oxidized lipids inhibits cell penetration, whereas extracellularly administered pure oxidized lipids enhance peptide transport into cells. Overall, these data indicate that oxidized lipids are capable of mediating the transport of polyarginine peptides across membranes. These data may also explain variability in cell-penetrating peptide performance in different experimental conditions. These new findings therefore provide new opportunities for the rational design of future cell-permeable compounds and for the optimization of delivery protocols.
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Affiliation(s)
- Ting-Yi Wang
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128
| | - Yusha Sun
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128
| | - Nandhini Muthukrishnan
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128
| | - Alfredo Erazo-Oliveras
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128
| | - Kristina Najjar
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128
| | - Jean-Philippe Pellois
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128
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11
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Lane DJR, Richardson DR. The active role of vitamin C in mammalian iron metabolism: much more than just enhanced iron absorption! Free Radic Biol Med 2014; 75:69-83. [PMID: 25048971 DOI: 10.1016/j.freeradbiomed.2014.07.007] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/04/2014] [Accepted: 07/08/2014] [Indexed: 01/18/2023]
Abstract
Ascorbate is a cofactor in numerous metabolic reactions. Humans cannot synthesize ascorbate owing to inactivation of the gene encoding the enzyme l-gulono-γ-lactone oxidase, which is essential for ascorbate synthesis. Accumulating evidence strongly suggests that in addition to the known ability of dietary ascorbate to enhance nonheme iron absorption in the gut, ascorbate within mammalian systems can regulate cellular iron uptake and metabolism. Ascorbate modulates iron metabolism by stimulating ferritin synthesis, inhibiting lysosomal ferritin degradation, and decreasing cellular iron efflux. Furthermore, ascorbate cycling across the plasma membrane is responsible for ascorbate-stimulated iron uptake from low-molecular-weight iron-citrate complexes, which are prominent in the plasma of individuals with iron-overload disorders. Importantly, this iron-uptake pathway is of particular relevance to astrocyte brain iron metabolism and tissue iron loading in disorders such as hereditary hemochromatosis and β-thalassemia. Recent evidence also indicates that ascorbate is a novel modulator of the classical transferrin-iron uptake pathway, which provides almost all iron for cellular demands and erythropoiesis under physiological conditions. Ascorbate acts to stimulate transferrin-dependent iron uptake by an intracellular reductive mechanism, strongly suggesting that it may act to stimulate iron mobilization from the endosome. The ability of ascorbate to regulate transferrin iron uptake could help explain the metabolic defect that contributes to ascorbate-deficiency-induced anemia.
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Affiliation(s)
- Darius J R Lane
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, NSW 2006, Australia.
| | - Des R Richardson
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, NSW 2006, Australia.
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12
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Michels AJ, Frei B. Myths, artifacts, and fatal flaws: identifying limitations and opportunities in vitamin C research. Nutrients 2013; 5:5161-92. [PMID: 24352093 PMCID: PMC3875932 DOI: 10.3390/nu5125161] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 11/23/2013] [Accepted: 11/27/2013] [Indexed: 01/01/2023] Open
Abstract
Research progress to understand the role of vitamin C (ascorbic acid) in human health has been slow in coming. This is predominantly the result of several flawed approaches to study design, often lacking a full appreciation of the redox chemistry and biology of ascorbic acid. In this review, we summarize our knowledge surrounding the limitations of common approaches used in vitamin C research. In human cell culture, the primary issues are the high oxygen environment, presence of redox-active transition metal ions in culture media, and the use of immortalized cell lines grown in the absence of supplemental ascorbic acid. Studies in animal models are also limited due to the presence of endogenous ascorbic acid synthesis. Despite the use of genetically altered rodent strains lacking synthesis capacity, there are additional concerns that these models do not adequately recapitulate the effects of vitamin C deprivation and supplementation observed in humans. Lastly, several flaws in study design endemic to randomized controlled trials and other human studies greatly limit their conclusions and impact. There also is anecdotal evidence of positive and negative health effects of vitamin C that are widely accepted but have not been substantiated. Only with careful attention to study design and experimental detail can we further our understanding of the possible roles of vitamin C in promoting human health and preventing or treating disease.
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Affiliation(s)
- Alexander J Michels
- Linus Pauling Institute, 307 Linus Pauling Science Center, Oregon State University, Corvallis, OR 97331, USA.
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Tveden-Nyborg P, Lykkesfeldt J. Does vitamin C deficiency increase lifestyle-associated vascular disease progression? Evidence based on experimental and clinical studies. Antioxid Redox Signal 2013; 19:2084-104. [PMID: 23642093 DOI: 10.1089/ars.2013.5382] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
SIGNIFICANCE Despite continuous advances in the prevention of cardiovascular disease (CVD), critical issues associated with an unhealthy lifestyle remain an increasing cause of morbidity and mortality in industrialized countries. RECENT ADVANCES A growing body of literature supports a specific role for vitamin C in a number of reactions that are associated with vascular function and control including, for example, nitric oxide bioavailability, lipid metabolism, and vascular integrity. CRITICAL ISSUES A large body of epidemiological evidence supports a relationship between poor vitamin C status and increased risk of developing CVD, and the prevalence of deficiency continues to be around 10%-20% of the general Western population although this problem could easily and cheaply be solved by supplementation. However, large intervention studies using vitamin C have not found a beneficial effect of supplementation. This review outlines the proposed mechanism by which vitamin C deficiency worsens CVD progression. In addition, it discusses problems with the currently available literature, including the discrepancies between the large intervention studies and the experimental and epidemiological literature. FUTURE DIRECTIONS Increased insights into vitamin C deficiency-mediated CVD progression will enable the design of future randomized controlled trials that are better suited to test the efficacy of vitamin C in disease prevention as well as the identification of high-risk individuals which could possibly benefit from supplementation.
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Affiliation(s)
- Pernille Tveden-Nyborg
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen , Frederiksberg, Denmark
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Manning J, Mitchell B, Appadurai DA, Shakya A, Pierce LJ, Wang H, Nganga V, Swanson PC, May JM, Tantin D, Spangrude GJ. Vitamin C promotes maturation of T-cells. Antioxid Redox Signal 2013; 19:2054-67. [PMID: 23249337 PMCID: PMC3869442 DOI: 10.1089/ars.2012.4988] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AIMS Vitamin C (ascorbic acid) is thought to enhance immune function, but the mechanisms involved are obscure. We utilized an in vitro model of T-cell maturation to evaluate the role of ascorbic acid in lymphocyte development. RESULTS Ascorbic acid was essential for the developmental progression of mouse bone marrow-derived progenitor cells to functional T-lymphocytes in vitro and also played a role in vivo. Ascorbate-mediated enhancement of T-cell development was lymphoid cell-intrinsic and independent of T-cell receptor (TCR) rearrangement. Analysis of TCR rearrangements demonstrated that ascorbic acid enhanced the selection of functional TCRαβ after the stage of β-selection. Genes encoding the coreceptor CD8 as well as the kinase ZAP70 were upregulated by ascorbic acid. Pharmacologic inhibition of methylation marks on DNA and histones enhanced ascorbate-mediated differentiation, suggesting an epigenetic mechanism of Cd8 gene regulation via active demethylation by ascorbate-dependent Fe(2+) and 2-oxoglutarate-dependent dioxygenases. INNOVATION We speculate that one aspect of gene regulation mediated by ascorbate occurs at the level of chromatin demethylation, mediated by Jumonji C (JmjC) domain enzymes that are known to be reliant upon ascorbate as a cofactor. JmjC domain enzymes are also known to regulate transcription factor activity. These two mechanisms are likely to play key roles in the modulation of immune development and function by ascorbic acid. CONCLUSION Our results provide strong experimental evidence supporting a role for ascorbic acid in T-cell maturation as well as insight into the mechanism of ascorbate-mediated enhancement of immune function.
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Affiliation(s)
- Jared Manning
- 1 Division of Hematology, Department of Medicine, University of Utah , Salt Lake City, Utah
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15
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Zeller KS, Riaz A, Sarve H, Li J, Tengholm A, Johansson S. The role of mechanical force and ROS in integrin-dependent signals. PLoS One 2013; 8:e64897. [PMID: 23738008 PMCID: PMC3667809 DOI: 10.1371/journal.pone.0064897] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 04/19/2013] [Indexed: 12/22/2022] Open
Abstract
Cells are exposed to several types of integrin stimuli, which generate responses generally referred to as “integrin signals”, but the specific responses to different integrin stimuli are poorly defined. In this study, signals induced by integrin ligation during cell attachment, mechanical force from intracellular contraction, or cell stretching by external force were compared. The elevated phosphorylation levels of several proteins during the early phase of cell attachment and spreading of fibroblast cell lines were not affected by inhibition of ROCK and myosin II activity, i.e. the reactions occurred independently of intracellular contractile force acting on the adhesion sites. The contraction-independent phosphorylation sites included ERK1/2 T202/Y204, AKT S473, p130CAS Y410, and cofilin S3. In contrast to cell attachment, cyclic stretching of the adherent cells induced a robust phosphorylation only of ERK1/2 and the phosphorylation levels of the other investigated proteins were not or only moderately affected by stretching. No major differences between signaling via α5β1 or αvβ3 integrins were detected. The importance of mitochondrial ROS for the integrin-induced signaling pathways was investigated using rotenone, a specific inhibitor of complex I in the respiratory chain. While rotenone only moderately reduced ATP levels and hardly affected the signals induced by cyclic cell stretching, it abolished the activation of AKT and reduced the actin polymerization rate in response to attachment in both cell lines. In contrast, scavenging of extracellular ROS with catalase or the vitamin C analog Asc-2P did not significantly influence the attachment-derived signaling, but caused a selective and pronounced enhancement of ERK1/2 phosphorylation in response to stretching. In conclusion, the results showed that “integrin signals” are composed of separate sets of reactions triggered by different types of integrin stimulation. Mitochondrial ROS and extracellular ROS had specific and distinct effects on the integrin signals induced by cell attachment and mechanical stretching.
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Affiliation(s)
- Kathrin S. Zeller
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Anjum Riaz
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Hamid Sarve
- Centre for Image Analysis, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Jia Li
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Staffan Johansson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
- * E-mail:
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16
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Lane DJR, Chikhani S, Richardson V, Richardson DR. Transferrin iron uptake is stimulated by ascorbate via an intracellular reductive mechanism. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1527-41. [PMID: 23481043 DOI: 10.1016/j.bbamcr.2013.02.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 02/14/2013] [Accepted: 02/15/2013] [Indexed: 02/08/2023]
Abstract
Although ascorbate has long been known to stimulate dietary iron (Fe) absorption and non-transferrin Fe uptake, the role of ascorbate in transferrin Fe uptake is unknown. Transferrin is a serum Fe transport protein supplying almost all cellular Fe under physiological conditions. We sought to examine ascorbate's role in this process, particularly as cultured cells are typically ascorbate-deficient. At typical plasma concentrations, ascorbate significantly increased (59)Fe uptake from transferrin by 1.5-2-fold in a range of cells. Moreover, ascorbate enhanced ferritin expression and increased (59)Fe accumulation in ferritin. The lack of effect of cycloheximide or the cytosolic aconitase inhibitor, oxalomalate, on ascorbate-mediated (59)Fe uptake from transferrin indicate increased ferritin synthesis or cytosolic aconitase activity was not responsible for ascorbate's activity. Experiments with membrane-permeant and -impermeant ascorbate-oxidizing reagents indicate that while extracellular ascorbate is required for stimulation of (59)Fe uptake from (59)Fe-citrate, only intracellular ascorbate is needed for transferrin (59)Fe uptake. Additionally, experiments with l-ascorbate analogs indicate ascorbate's reducing ene-diol moiety is necessary for its stimulatory activity. Importantly, neither N-acetylcysteine nor buthionine sulfoximine, which increase or decrease intracellular glutathione, respectively, affected transferrin-dependent (59)Fe uptake. Thus, ascorbate's stimulatory effect is not due to a general increase in cellular reducing capacity. Ascorbate also did not affect expression of transferrin receptor 1 or (125)I-transferrin cellular flux. However, transferrin receptors, endocytosis, vacuolar-type ATPase activity and endosomal acidification were required for ascorbate's stimulatory activity. Therefore, ascorbate is a novel modulator of the classical transferrin Fe uptake pathway, acting via an intracellular reductive mechanism.
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Affiliation(s)
- Darius J R Lane
- Department of Pathology, University of Sydney, Sydney, New South Wales, Australia.
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17
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Olney KE, Du J, van 't Erve TJ, Witmer JR, Sibenaller ZA, Wagner BA, Buettner GR, Cullen JJ. Inhibitors of hydroperoxide metabolism enhance ascorbate-induced cytotoxicity. Free Radic Res 2013. [PMID: 23205739 DOI: 10.3109/10715762.2012.755263] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Pharmacological ascorbate, via its oxidation, has been proposed as a pro-drug for the delivery of H(2)O(2) to tumors. Pharmacological ascorbate decreases clonogenic survival of pancreatic cancer cells, which can be reversed by treatment with scavengers of H(2)O(2). The goal of this study was to determine if inhibitors of intracellular hydroperoxide detoxification could enhance the cytotoxic effects of ascorbate. Human pancreatic cancer cells were treated with ascorbate alone or in combination with inhibitors of hydroperoxide removal including the glutathione disulfide reductase inhibitor 1,3 bis (2-chloroethyl)-1-nitrosurea (BCNU), siRNA targeted to glutathione disulfide reductase (siGR), and 2-deoxy-D-glucose (2DG), which inhibits glucose metabolism. Changes in the intracellular concentration of H(2)O(2) were determined by analysis of the rate of aminotriazole-mediated inactivation of endogenous catalase activity. Pharmacological ascorbate increased intracellular H(2)O(2) and depleted intracellular glutathione. When inhibitors of H(2)O(2) metabolism were combined with pharmacological ascorbate the increase in intracellular H(2)O(2) was amplified and cytotoxicity was enhanced. We conclude that inclusion of agents that inhibit cellular peroxide removal produced by pharmacological ascorbate leads to changes in the intracellular redox state resulting in enhanced cytotoxicity.
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Affiliation(s)
- K E Olney
- Department of Radiation Oncology, University of Iowa , Iowa City, IA 52242, USA
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Frikke-Schmidt H, Roursgaard M, Lykkesfeldt J, Loft S, Nøjgaard JK, Møller P. Effect of vitamin C and iron chelation on diesel exhaust particle and carbon black induced oxidative damage and cell adhesion molecule expression in human endothelial cells. Toxicol Lett 2011; 203:181-9. [PMID: 21421028 DOI: 10.1016/j.toxlet.2011.03.011] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 03/04/2011] [Accepted: 03/07/2011] [Indexed: 01/07/2023]
Abstract
Exposure to particulate matter is associated with oxidative stress and risk of cardiovascular diseases. We investigated if vitamin C and desferrioxamine (iron chelator) altered the levels of oxidative stress and expression of cell adhesion molecules upon exposure to diesel exhaust particles (DEP) and carbon black in cultured human umbilical vein endothelial cells (HUVECs). We found that the particles were only slightly cytotoxic in the high concentration ranges. Particle-induced intracellular reactive oxygen species (ROS) production was attenuated by vitamin C administration or iron chelation and particularly when combined (p<0.001). Only desferrioxamine protected the DNA from oxidative damage in terms of strand breaks and formamidopyrimidine DNA glycosylase sensitive sites induced by carbon black (p<0.01). Carbon black and small sized DEP generated from an Euro4 engine increased the surface expression of VCAM-1 and ICAM-1, whereas DEP from an engine representing an old combustion type engine (SRM2975) with larger particles did not affect the expression of cell adhesion molecules. These effects were also attenuated by desferrioxamine but not vitamin C. The study shows that exposure to carbon black and DEP in HUVECs can generate both oxidative stress and expression of cell surface adhesion molecules and that these effects can in part be attenuated by vitamin C and desferrioxamine.
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Affiliation(s)
- Henriette Frikke-Schmidt
- Section of Biomedicine, Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, Denmark
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Two routes of iron accumulation in astrocytes: ascorbate-dependent ferrous iron uptake via the divalent metal transporter (DMT1) plus an independent route for ferric iron. Biochem J 2010; 432:123-32. [PMID: 20819077 DOI: 10.1042/bj20101317] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Astrocytes are central to iron and ascorbate homoeostasis within the brain. Although NTBI (non-transferrin-bound iron) may be a major form of iron imported by astrocytes in vivo, the mechanisms responsible remain unclear. The present study examines NTBI uptake by cultured astrocytes and the involvement of ascorbate and DMT1 (divalent metal transporter 1). We demonstrate that iron accumulation by ascorbate-deficient astrocytes is insensitive to both membrane-impermeant Fe(II) chelators and to the addition of the ferroxidase caeruloplasmin. However, when astrocytes are ascorbate-replete, as occurs in vivo, their rate of iron accumulation is doubled. The acquisition of this additional iron depends on effluxed ascorbate and can be blocked by the DMT1 inhibitor ferristatin/NSC306711. Furthermore, the calcein-accessible component of intracellular labile iron, which appears during iron uptake, appears to consist of only Fe(III) in ascorbate-deficient astrocytes, whereas that of ascorbate-replete astrocytes comprises both valencies. Our data suggest that an Fe(III)-uptake pathway predominates when astrocytes are ascorbate-deficient, but that in ascorbate-replete astrocytes, at least half of the accumulated iron is initially reduced by effluxed ascorbate and then imported by DMT1. These results suggest that ascorbate is intimately involved in iron accumulation by astrocytes, and is thus an important contributor to iron homoeostasis in the mammalian brain.
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