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Fletcher BD, Haszard JJ, Vissers MCM, Conner TS. Smartphone survey data reveal the timecourse of changes in mood outcomes following vitamin C or kiwifruit intervention in adults with low vitamin C. Br J Nutr 2024; 131:1384-1396. [PMID: 38073290 PMCID: PMC10950451 DOI: 10.1017/s0007114523002787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 11/09/2023] [Accepted: 11/20/2023] [Indexed: 01/23/2024]
Abstract
Vitamin C-rich foods can improve mood; however, the timecourse of these benefits is unknown. This study utilised intensive longitudinal smartphone surveys from a three-armed placebo-controlled trial to determine mood-related changes following supplementation with vitamin C (250 mg tablet/d), kiwifruit (2 SunGold™ kiwifruit/d) or a placebo (1 tablet/d). Secondary data were analysed from the KiwiC for Vitality trial (Trial ID: ACTRN12617001031358). Adults (n 155, 63 % female, aged 18-35 years) with low plasma vitamin C (<40 μmol/l) completed a 14-d lead-in, 28-d intervention and 14-d washout. Participants self-reported vitality (SF-36), mood (POMS total mood disturbance), flourishing (flourishing scale), sleep quality, sleep quantity and physical activity every second day using smartphone surveys. Plasma vitamin C, measured fortnightly, reached saturation after 2 weeks of vitamin C or kiwifruit supplementation. Kiwifruit supplementation improved vitality and mood within 4 days, peaking around 14-16 days, and improved flourishing from day 14. Vitamin C marginally improved mood until day 12. Incremental AUC analyses revealed significant overall effects of kiwifruit consumption on vitality and mood compared with placebo, which were stronger than effects for vitamin C tablets, but attenuated when adjusting for covariates. Sensitivity analyses of participants with low baseline vitamin C status revealed improved mood (vitamin C and kiwifruit) and flourishing (kiwifruit only). This is the first study to use intensive smartphone surveys to model the day-to-day timecourse of mood-related states following vitamin C intervention and highlights the value of using smartphone surveys to reveal the temporal changes in mood-related outcomes following nutrient supplementation.
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Affiliation(s)
- Benjamin D. Fletcher
- Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | | | - Margreet C. M. Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Tamlin S. Conner
- Department of Psychology, University of Otago, Dunedin, New Zealand
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2
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Coker SJ, Berry MJ, Vissers MCM, Dyson RM. Maternal Vitamin C Intake during Pregnancy Influences Long-Term Offspring Growth with Timing- and Sex-Specific Effects in Guinea Pigs. Nutrients 2024; 16:369. [PMID: 38337653 PMCID: PMC10857109 DOI: 10.3390/nu16030369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/18/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
Our previous work in guinea pigs revealed that low vitamin C intake during preconception and pregnancy adversely affects fertility, pregnancy outcomes, and foetal and neonatal growth in a sex-dependent manner. To investigate the long-term impact on offspring, we monitored their growth from birth to adolescence (four months), recorded organ weights at childhood equivalence (28 days) and adolescence, and assessed physiological parameters like oral glucose tolerance and basal cortisol concentrations. We also investigated the effects of the timing of maternal vitamin C restriction (early vs. late gestation) on pregnancy outcomes and the health consequences for offspring. Dunkin Hartley guinea pigs were fed an optimal (900 mg/kg feed) or low (100 mg/kg feed) vitamin C diet ad libitum during preconception. Pregnant dams were then randomised into four feeding regimens: consistently optimal, consistently low, low during early pregnancy, or low during late pregnancy. We found that low maternal vitamin C intake during early pregnancy accelerated foetal and neonatal growth in female offspring and altered glucose homeostasis in the offspring of both sexes at an age equivalent to early childhood. Conversely, low maternal vitamin C intake during late pregnancy resulted in foetal growth restriction and reduced weight gain in male offspring throughout their lifespan. We conclude that altered vitamin C during development has long-lasting, sex-specific consequences for offspring and that the timing of vitamin C depletion is also critical, with low levels during early development being associated with the development of a metabolic syndrome-related phenotype, while later deprivation appears to be linked to a growth-faltering phenotype.
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Affiliation(s)
- Sharna J. Coker
- Perinatal and Developmental Physiology Group, Department of Paediatrics and Child Health, University of Otago, Wellington 6242, New Zealand; (M.J.B.); (R.M.D.)
| | - Mary J. Berry
- Perinatal and Developmental Physiology Group, Department of Paediatrics and Child Health, University of Otago, Wellington 6242, New Zealand; (M.J.B.); (R.M.D.)
| | - Margreet C. M. Vissers
- Mātai Hāora-Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand;
| | - Rebecca M. Dyson
- Perinatal and Developmental Physiology Group, Department of Paediatrics and Child Health, University of Otago, Wellington 6242, New Zealand; (M.J.B.); (R.M.D.)
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3
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Peeters WM, Gram M, Dias GJ, Vissers MCM, Hampton MB, Dickerhof N, Bekhit AE, Black MJ, Oxbøll J, Bayer S, Dickens M, Vitzel K, Sheard PW, Danielson KM, Hodges LD, Brønd JC, Bond J, Perry BG, Stoner L, Cornwall J, Rowlands DS. Changes to insulin sensitivity in glucose clearance systems and redox following dietary supplementation with a novel cysteine-rich protein: A pilot randomized controlled trial in humans with type-2 diabetes. Redox Biol 2023; 67:102918. [PMID: 37812879 PMCID: PMC10570009 DOI: 10.1016/j.redox.2023.102918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 10/02/2023] [Indexed: 10/11/2023] Open
Abstract
We recently developed a novel keratin-derived protein (KDP) rich in cysteine, glycine, and arginine, with the potential to alter tissue redox status and insulin sensitivity. The KDP was tested in 35 human adults with type-2 diabetes mellitus (T2DM) in a 14-wk randomised controlled pilot trial comprising three 2×20 g supplemental protein/day arms: KDP-whey (KDPWHE), whey (WHEY), non-protein isocaloric control (CON), with standardised exercise. Outcomes were measured morning fasted and following insulin-stimulation (80 mU/m2/min hyperinsulinaemic-isoglycaemic clamp). With KDPWHE supplementation there was good and very-good evidence for moderate-sized increases in insulin-stimulated glucose clearance rate (GCR; 26%; 90% confidence limits, CL 2%, 49%) and skeletal-muscle microvascular blood flow (46%; 16%, 83%), respectively, and good evidence for increased insulin-stimulated sarcoplasmic GLUT4 translocation (18%; 0%, 39%) vs CON. In contrast, WHEY did not effect GCR (-2%; -25%, 21%) and attenuated HbA1c lowering (14%; 5%, 24%) vs CON. KDPWHE effects on basal glutathione in erythrocytes and skeletal muscle were unclear, but in muscle there was very-good evidence for large increases in oxidised peroxiredoxin isoform 2 (oxiPRX2) (19%; 2.2%, 35%) and good evidence for lower GPx1 concentrations (-40%; -4.3%, -63%) vs CON; insulin stimulation, however, attenuated the basal oxiPRX2 response (4%; -16%, 24%), and increased GPx1 (39%; -5%, 101%) and SOD1 (26%; -3%, 60%) protein expression. Effects of KDPWHE on oxiPRX3 and NRF2 content, phosphorylation of capillary eNOS and insulin-signalling proteins upstream of GLUT4 translocation AktSer437 and AS160Thr642 were inconclusive, but there was good evidence for increased IRSSer312 (41%; 3%, 95%), insulin-stimulated NFκB-DNA binding (46%; 3.4%, 105%), and basal PAK-1Thr423/2Thr402 phosphorylation (143%; 66%, 257%) vs WHEY. Our findings provide good evidence to suggest that dietary supplementation with a novel edible keratin protein in humans with T2DM may increase glucose clearance and modify skeletal-muscle tissue redox and insulin sensitivity within systems involving peroxiredoxins, antioxidant expression, and glucose uptake.
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Affiliation(s)
- W M Peeters
- Metabolic and Microvascular Laboratory, School of Sport, Exercise and Nutrition, Massey University, Wellington, Auckland, New Zealand; School of Biomedical, Nutritional and Sport Science, Newcastle University, United Kingdom
| | - M Gram
- Metabolic and Microvascular Laboratory, School of Sport, Exercise and Nutrition, Massey University, Wellington, Auckland, New Zealand
| | - G J Dias
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - M C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - M B Hampton
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - N Dickerhof
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - A E Bekhit
- Department of Food Sciences, University of Otago, Dunedin, New Zealand
| | - M J Black
- Metabolic and Microvascular Laboratory, School of Sport, Exercise and Nutrition, Massey University, Wellington, Auckland, New Zealand
| | - J Oxbøll
- Metabolic and Microvascular Laboratory, School of Sport, Exercise and Nutrition, Massey University, Wellington, Auckland, New Zealand
| | - S Bayer
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - M Dickens
- School of Health Sciences, Massey University, Wellington, Auckland, New Zealand
| | - K Vitzel
- School of Health Sciences, Massey University, Wellington, Auckland, New Zealand
| | - P W Sheard
- Department of Physiology, University of Otago, Dunedin, New Zealand
| | - K M Danielson
- Department of Anaesthesiology and Surgery, University of Otago, Wellington, New Zealand
| | - L D Hodges
- Metabolic and Microvascular Laboratory, School of Sport, Exercise and Nutrition, Massey University, Wellington, Auckland, New Zealand
| | - J C Brønd
- Department of Sports Science and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - J Bond
- Metabolic and Microvascular Laboratory, School of Sport, Exercise and Nutrition, Massey University, Wellington, Auckland, New Zealand
| | - B G Perry
- School of Health Sciences, Massey University, Wellington, Auckland, New Zealand
| | - L Stoner
- Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, USA
| | - J Cornwall
- Centre for Early Learning in Medicine, University of Otago, Dunedin, New Zealand
| | - D S Rowlands
- Metabolic and Microvascular Laboratory, School of Sport, Exercise and Nutrition, Massey University, Wellington, Auckland, New Zealand.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Coker SJ, Dyson RM, Smith-Díaz CC, Vissers MCM, Berry MJ. Effects of Low Vitamin C Intake on Fertility Parameters and Pregnancy Outcomes in Guinea Pigs. Nutrients 2023; 15:4107. [PMID: 37836389 PMCID: PMC10574174 DOI: 10.3390/nu15194107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/21/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023] Open
Abstract
Identifying how specific nutrients can impact fertility, pregnancy, and neonatal outcomes will yield important insights into the biological mechanisms linking diet and reproductive health. Our study investigates how dietary vitamin C intake affects various fertility parameters and pregnancy and neonatal outcomes in the guinea pig, a natural model of vitamin C dependency. Dunkin Hartley guinea pigs were fed an optimal (900 mg/kg feed) or low (100 mg/kg feed) vitamin C diet ad libitum for at least three weeks prior to mating and throughout pregnancy. We found that animals receiving the low vitamin C diet had an increased number of unsuccessful matings, a higher incidence of foetal reabsorption, and, among pregnancies resulting in delivery at term, produced fewer offspring. Neonates from mothers on the low vitamin C diet had significantly decreased plasma vitamin C concentrations at birth and exhibited mild growth impairments in a sex-dependent manner. We conclude that a diet low of vitamin C induces a state of subfertility, reduces overall fecundity, and adversely impacts both pregnancy outcomes and growth in the offspring. Our study provides an essential foundation for future investigations to determine whether these findings translate to humans. If so, they could have important clinical implications for assisted reproductive technologies and nutritional recommendations for couples trying to conceive, pregnant women, and breastfeeding mothers.
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Affiliation(s)
- Sharna J. Coker
- Perinatal and Developmental Physiology Group, Department of Paediatrics and Child Health, University of Otago, Wellington 6242, New Zealand; (S.J.C.); (R.M.D.)
| | - Rebecca M. Dyson
- Perinatal and Developmental Physiology Group, Department of Paediatrics and Child Health, University of Otago, Wellington 6242, New Zealand; (S.J.C.); (R.M.D.)
| | - Carlos C. Smith-Díaz
- Mātai Hāora—Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand;
| | - Margreet C. M. Vissers
- Mātai Hāora—Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand;
| | - Mary J. Berry
- Perinatal and Developmental Physiology Group, Department of Paediatrics and Child Health, University of Otago, Wellington 6242, New Zealand; (S.J.C.); (R.M.D.)
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Bozonet SM, Magon NJ, Schwartfeger AJ, Konigstorfer A, Heath SG, Vissers MCM, Morris VK, Göbl C, Murphy JM, Salvesen GS, Hampton MB. Oxidation of caspase-8 by hypothiocyanous acid enables TNF-mediated necroptosis. J Biol Chem 2023:104792. [PMID: 37150321 DOI: 10.1016/j.jbc.2023.104792] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/18/2023] [Accepted: 04/19/2023] [Indexed: 05/09/2023] Open
Abstract
Necroptosis is a form of regulated cell death triggered by various host and pathogen-derived molecules during infection and inflammation. The essential step leading to necroptosis is phosphorylation of the mixed lineage kinase domain-like protein (MLKL) by receptor-interacting protein kinase 3 (RIPK3). Caspase 8 cleaves RIPKs to block necroptosis, so synthetic caspase inhibitors are required to study this process in experimental models. However, it is unclear how caspase-8 activity is regulated in a physiological setting. The active site cysteine of caspases is sensitive to oxidative inactivation, so we hypothesized that oxidants generated at sites of inflammation can inhibit caspase-8 and promote necroptosis. Here, we discovered that hypothiocyanous acid (HOSCN), an oxidant generated in vivo by heme peroxidases including myeloperoxidase and lactoperoxidase, is a potent caspase-8 inhibitor. We found HOSCN was able to promote necroptosis in mouse fibroblasts treated with tumor necrosis factor (TNF). We also demonstrate purified caspase-8 was inactivated by low concentrations of HOSCN, with the predominant product being a disulfide-linked dimer between Cys360 and Cys409 of the large and small catalytic subunits. We show oxidation still occurred in the presence of reducing agents, and reduction of the dimer was slow, consistent with HOSCN being a powerful physiological caspase inhibitor. While the initial oxidation product is a dimer, further modification also occurred in cells treated with HOSCN, leading to higher molecular weight caspase-8 species. Taken together, these findings indicate major disruption of caspase-8 function, and suggest a novel mechanism for the promotion of necroptosis at sites of inflammation.
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Affiliation(s)
- S M Bozonet
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - N J Magon
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - A J Schwartfeger
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - A Konigstorfer
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - S G Heath
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - M C M Vissers
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - V K Morris
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - C Göbl
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand; School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - J M Murphy
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - G S Salvesen
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - M B Hampton
- Mātai Hāora - Centre for Redox Biology and Medicine, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand.
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Conner TS, Fletcher BD, Haszard JJ, Pullar JM, Spencer E, Mainvil LA, Vissers MCM. Correction: Conner et al. KiwiC for Vitality: Results of a Placebo-Controlled Trial Testing the Effects of Kiwifruit or Vitamin C Tablets on Vitality in Adults with Low Vitamin C Levels. Nutrients 2020, 12, 2898. Nutrients 2022; 14:nu14194063. [PMID: 36235871 PMCID: PMC9555711 DOI: 10.3390/nu14194063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 09/05/2022] [Indexed: 12/03/2022] Open
Abstract
In the original publication title [...].
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Affiliation(s)
- Tamlin S. Conner
- Department of Psychology, University of Otago, Dunedin 9054, New Zealand
- Correspondence: ; Tel.: +64-3-479-7624
| | | | - Jillian J. Haszard
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand
| | - Juliet M. Pullar
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand
| | - Emma Spencer
- Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand
| | - Louise A. Mainvil
- Department of Human Nutrition, University of Otago, Dunedin 9054, New Zealand
| | - Margreet C. M. Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand
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Conner TS, Fletcher BD, Haszard JJ, Pullar JM, Spencer E, Mainvil LA, Vissers MCM. Reply to Vorland et al. Mixed Random and Nonrandom Allocation, and Group Randomization Have Been Mislabeled and Misanalysed, Necessitating Reanalysis. Comment on "Conner et al. KiwiC for Vitality: Results of a Randomized Placebo-Controlled Trial Testing the Effects of Kiwifruit or Vitamin C Tablets on Vitality in Adults with Low Vitamin C Levels. Nutrients 2020, 12, 2898". Nutrients 2022; 14:nu14194065. [PMID: 36235717 PMCID: PMC9571931 DOI: 10.3390/nu14194065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
We have read the Comment article by Vorland et al. [...].
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Affiliation(s)
- Tamlin S. Conner
- Department of Psychology, University of Otago, Dunedin 9054, New Zealand
- Correspondence: ; Tel.: +64-3-479-7624
| | | | - Jillian J. Haszard
- Biostatistics Centre and Division of Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Juliet M. Pullar
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand
| | - Emma Spencer
- Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand
| | - Louise A. Mainvil
- Department of Human Nutrition, University of Otago, Dunedin 9054, New Zealand
| | - Margreet C. M. Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand
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Burgess ER, Wiggins GAR, Phillips E, Morrin H, Crake RLI, Slatter T, Royds J, Vissers MCM, Robinson BA, Dachs GU. P12.03.B Ascorbate alters the hypoxic pathway in glioblastoma cells in vitro and associates with improved patient survival. Neuro Oncol 2022. [DOI: 10.1093/neuonc/noac174.268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Glioblastomas are highly aggressive and hypoxic tumours. This environment activates the hypoxic pathway, driving glioma progression and treatment resistance. The hypoxic pathway is regulated by the hypoxia inducible factor (HIF) hydroxylases, which require oxygen as a substrate. Under normoxic conditions, the HIF hydroxylases are active, causing degradation and inhibition of HIF transcription factors. Under hypoxia, the activity of the hydroxylases reduces and HIF accumulates, activating the hypoxic response. HIF hydroxylases also require ascorbate as a cofactor for optimal function. The brain has one of the highest ascorbate levels in the human body, yet data on ascorbate levels in gliomas is scarce. Cellular ascorbate uptake occurs through solute carrier family 23 member 2 (SLC23A2). My aim is to understand the relationship between ascorbate, SLC23A2 and the hypoxic pathway in brain cancer using both in vitro cell culture and clinical samples.
Material and Methods
Ascorbate uptake was measured in human glioblastoma cell lines (T98G, U251MG, U87MG; ATCC) using reverse phase high performance liquid chromatography (HPLC-ECD). CRISPR-Cas was designed to knock-out SLC23A2. Clinical glioblastoma samples (n=37) and follow-up data were provided by the Cancer Society Tissue Bank and University of Otago Dunedin. Ethics and informed consent were obtained (H19/163, MEC/08/02/016). Ascorbate levels, measured by HPLC-ECD, and HIF-1α and downstream targets were measured using Western blotting or ELISA. A HIF score was calculated from HIF-1α and downstream target protein levels to estimate hypoxic pathway activity.
Results
In this study we have shown that T98G and U251 cells accumulate up to 15 nmol ascorbate/106 cells when exposed to 500 µM ascorbate for up to 24 hours, compared to U87MG cells with up to 3 nmol ascorbate/106 cells. Cancer Cell Line Encyclopaedia data shows that T98G and U251MG cells express higher levels of SLC23A2 compared to U87MG cells, aligning with our results. Clinical glioblastoma tissue contained a median of 7.6 µg ascorbate/100 mg tissue. Patients survival was significantly longer with above, vs below, median tumour ascorbate levels (Gehan-Breslow-Wilcoxon p = 0.027). The HIF score was negatively correlated with tumour ascorbate levels (Pearson r -0.327, p = 0.048). Patients with higher HIF-score had significantly shorter survival time compared to those with a lower HIF score (Gehan-Breslow-Wilcoxon p = 0.005).
Conclusion
Ascorbate uptake in glioblastoma cells varies between cell lines and appears reliant on the level of SLC23A2. Higher ascorbate content in clinical glioblastoma samples was associated with reduced hypoxic pathway activity and longer patient survival. Ongoing work, using SLC23A2 CRISPR-Cas knock-out cells, is investigating the effect of disrupting ascorbate uptake on hypoxic pathway signalling in glioblastoma cells.
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Affiliation(s)
- E R Burgess
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand
| | - G A R Wiggins
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand
| | - E Phillips
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand
| | - H Morrin
- Cancer Society Tissue Bank, University of Otago , Christchurch , New Zealand
| | - R L I Crake
- Metastasis Research Laboratory, GIGA-Cancer, University of Liège , Liège , Belgium
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand
| | - T Slatter
- Department of Pathology, Dunedin School of Medicine, University of Otago , Dunedin , New Zealand
| | - J Royds
- Department of Pathology, Dunedin School of Medicine, University of Otago , Dunedin , New Zealand
| | - M C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science University of Otago Christchurch , Christchurch , New Zealand
| | - B A Robinson
- Canterbury Regional Cancer and Haematology Service, Canterbury District Health Board , Christchurch , New Zealand
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand
| | - G U Dachs
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand
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Crake RLI, Burgess ER, Wiggins GAR, Magon NJ, Das AB, Vissers MCM, Morrin HR, Royds JA, Slatter TL, Robinson BA, Phillips E, Dachs GU. P12.06.A Relationship between ascorbate and DNA methylation markers in clinical glioma tumours. Neuro Oncol 2022. [DOI: 10.1093/neuonc/noac174.271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Members of the 2-oxoglutarate-dependent dioxygenase (OGDD) enzyme family play an important role in gliomas as they regulate epigenetic modifications and response to hypoxia. The OGDDs require 2-OG and O2 as substrates, and ferrous iron and ascorbate as cofactors. Both hypoxia and aberrant DNA methylation are prognostic indicators for gliomas. The ten-eleven translocase (TET) DNA demethylases are OGDDs that convert 5-methyl cytosine (5mC) to 5-hydroxymethylcytosine (5hmC), with 5hmC levels related to better prognosis. Despite this, there is limited data on the OGDD enzymes and their substrates/cofactors in glioma tissues. Our previous study showed an association between ascorbate content and markers of the hypoxic response in glioblastoma tissue. Here we determine whether there is an association between ascorbate and DNA methylation in glioma. In addition, we assess whether methylation of the methylguanine-DNA methyltransferase (DNA repair enzyme MGMT) promoter is associated with ascorbate content.
Materials and methods
Frozen clinical glioma samples from 37 patients (n=11 WHO grade I-III, n=26 glioblastoma) were obtained from the Cancer Society Tissue Bank (Ethics approval H19/163). Isocitrate dehydrogenase 1 (IDH1) mutation status was determined by sequencing. Samples were processed on dry ice in liquid nitrogen and analysed for ascorbate (high-performance liquid chromatography), global DNA methylation (mass spectrometry) and MGMT promoter analyses (methylation specific PCR).
Results
Many grade I-III tumours were IDH1 R132H mutant (6/11), and most glioblastomas were not (2/26). Glioblastoma had significantly lower ascorbate content than grade I-III tumours (p=0.026). Glioblastoma also had lower global 5hmC levels (p=0.0013). IDH1 R132H tumours tended to have a lower ascorbate content (p=0.09). Ascorbate and 5hmC levels were directly correlated (Spearman r= 0.466, p=0.004). However, cytosine and 5mC showed no association with grade or ascorbate. MGMT promoter methylation status was not associated with global methylation or ascorbate content (p=0.97, p=0.96, respectively).
Conclusion
Our data suggests that ascorbate supports TET activity in clinical glioma. It also appears that site-specific (promoter) methylation was not affected by ascorbate availability. These findings may have clinical implications, as higher 5hmC levels are associated with improved outcome, whilst continued MGMT suppression suggests chemotherapy responsiveness. However, evidence that raising tumour ascorbate leads to increased 5hmC levels, or an associated improvement in survival, requires intervention trials.
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Affiliation(s)
| | - E R Burgess
- University of Otago Christchurch , Christchurch , New Zealand
| | - G A R Wiggins
- University of Otago Christchurch , Christchurch , New Zealand
| | - N J Magon
- University of Otago Christchurch , Christchurch , New Zealand
| | - A B Das
- Peter MacCallum Cancer Centre , Melbourne , Australia
| | - M C M Vissers
- University of Otago Christchurch , Christchurch , New Zealand
| | - H R Morrin
- University of Otago Christchurch , Christchurch , New Zealand
| | - J A Royds
- University of Otago , Dunedin , New Zealand
| | | | - B A Robinson
- Canterbury District Health Board , Christchurch , New Zealand
| | - E Phillips
- University of Otago Christchurch , Christchurch , New Zealand
| | - G U Dachs
- University of Otago Christchurch , Christchurch , New Zealand
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11
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Burgess ER, Crake RLI, Phillips E, Morrin HR, Royds JA, Slatter TL, Wiggins GAR, Vissers MCM, Robinson BA, Dachs GU. Increased Ascorbate Content of Glioblastoma Is Associated With a Suppressed Hypoxic Response and Improved Patient Survival. Front Oncol 2022; 12:829524. [PMID: 35419292 PMCID: PMC8995498 DOI: 10.3389/fonc.2022.829524] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 02/23/2022] [Indexed: 12/13/2022] Open
Abstract
Glioblastoma multiforme is a challenging disease with limited treatment options and poor survival. Glioblastoma tumours are characterised by hypoxia that activates the hypoxia inducible factor (HIF) pathway and controls a myriad of genes that drive cancer progression. HIF transcription factors are regulated at the post-translation level via HIF-hydroxylases. These hydroxylases require oxygen and 2-oxoglutarate as substrates, and ferrous iron and ascorbate as cofactors. In this retrospective observational study, we aimed to determine whether ascorbate played a role in the hypoxic response of glioblastoma, and whether this affected patient outcome. We measured the ascorbate content and members of the HIF-pathway of clinical glioblastoma samples, and assessed their association with clinicopathological features and patient survival. In 37 samples (37 patients), median ascorbate content was 7.6 μg ascorbate/100 mg tissue, range 0.8 – 20.4 μg ascorbate/100 mg tissue. In tumours with above median ascorbate content, HIF-pathway activity as a whole was significantly suppressed (p = 0.005), and several members of the pathway showed decreased expression (carbonic anhydrase-9 and glucose transporter-1, both p < 0.01). Patients with either lower tumour HIF-pathway activity or higher tumour ascorbate content survived significantly longer than patients with higher HIF-pathway or lower ascorbate levels (p = 0.011, p = 0.043, respectively). Median survival for the low HIF-pathway score group was 362 days compared to 203 days for the high HIF-pathway score group, and median survival for the above median ascorbate group was 390 days, compared to the below median ascorbate group with 219 days. The apparent survival advantage associated with higher tumour ascorbate was more prominent for the first 8 months following surgery. These associations are promising, suggesting an important role for ascorbate-regulated HIF-pathway activity in glioblastoma that may impact on patient survival.
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Affiliation(s)
- Eleanor R Burgess
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Rebekah L I Crake
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand.,Metastasis Research Laboratory, GIGA-Cancer, University of Liège, Liege, Belgium
| | - Elisabeth Phillips
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Helen R Morrin
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand.,Cancer Society Tissue Bank, University of Otago Christchurch, Christchurch, New Zealand
| | - Janice A Royds
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Tania L Slatter
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - George A R Wiggins
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Bridget A Robinson
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand.,Canterbury Regional Cancer and Haematology Service, Canterbury District Health Board, and Department of Medicine, University of Otago Christchurch, Christchurch, New Zealand
| | - Gabi U Dachs
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
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12
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Coker SJ, Smith-Díaz CC, Dyson RM, Vissers MCM, Berry MJ. The Epigenetic Role of Vitamin C in Neurodevelopment. Int J Mol Sci 2022; 23:ijms23031208. [PMID: 35163133 PMCID: PMC8836017 DOI: 10.3390/ijms23031208] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/16/2022] [Accepted: 01/17/2022] [Indexed: 02/07/2023] Open
Abstract
The maternal diet during pregnancy is a key determinant of offspring health. Early studies have linked poor maternal nutrition during gestation with a propensity for the development of chronic conditions in offspring. These conditions include cardiovascular disease, type 2 diabetes and even compromised mental health. While multiple factors may contribute to these outcomes, disturbed epigenetic programming during early development is one potential biological mechanism. The epigenome is programmed primarily in utero, and during this time, the developing fetus is highly susceptible to environmental factors such as nutritional insults. During neurodevelopment, epigenetic programming coordinates the formation of primitive central nervous system structures, neurogenesis, and neuroplasticity. Dysregulated epigenetic programming has been implicated in the aetiology of several neurodevelopmental disorders such as Tatton-Brown-Rahman syndrome. Accordingly, there is great interest in determining how maternal nutrient availability in pregnancy might affect the epigenetic status of offspring, and how such influences may present phenotypically. In recent years, a number of epigenetic enzymes that are active during embryonic development have been found to require vitamin C as a cofactor. These enzymes include the ten-eleven translocation methylcytosine dioxygenases (TETs) and the Jumonji C domain-containing histone lysine demethylases that catalyse the oxidative removal of methyl groups on cytosines and histone lysine residues, respectively. These enzymes are integral to epigenetic regulation and have fundamental roles in cellular differentiation, the maintenance of pluripotency and development. The dependence of these enzymes on vitamin C for optimal catalytic activity illustrates a potentially critical contribution of the nutrient during mammalian development. These insights also highlight a potential risk associated with vitamin C insufficiency during pregnancy. The link between vitamin C insufficiency and development is particularly apparent in the context of neurodevelopment and high vitamin C concentrations in the brain are indicative of important functional requirements in this organ. Accordingly, this review considers the evidence for the potential impact of maternal vitamin C status on neurodevelopmental epigenetics.
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Affiliation(s)
- Sharna J. Coker
- Perinatal & Developmental Physiology Group, Department of Paediatrics & Child Health, University of Otago, Wellington 6242, New Zealand; (S.J.C.); (R.M.D.)
| | - Carlos C. Smith-Díaz
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand;
| | - Rebecca M. Dyson
- Perinatal & Developmental Physiology Group, Department of Paediatrics & Child Health, University of Otago, Wellington 6242, New Zealand; (S.J.C.); (R.M.D.)
| | - Margreet C. M. Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8140, New Zealand;
- Correspondence: (M.C.M.V.); (M.J.B.)
| | - Mary J. Berry
- Perinatal & Developmental Physiology Group, Department of Paediatrics & Child Health, University of Otago, Wellington 6242, New Zealand; (S.J.C.); (R.M.D.)
- Correspondence: (M.C.M.V.); (M.J.B.)
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13
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Vissers MCM, Pullar JM. Re-opening old wounds-vitamin C and wound healing deserve a re-examination. Am J Clin Nutr 2022; 115:1-2. [PMID: 34510171 DOI: 10.1093/ajcn/nqab300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, Christchurch, New Zealand
| | - Juliet M Pullar
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, Christchurch, New Zealand
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14
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Wohlrab C, Vissers MCM, Burgess ER, Nonis M, Phillips E, Robinson BA, Dachs GU. Limited Association Between Ascorbate Concentrations and Vitamin C Transporters in Renal Cell Carcinoma Cells and Clinical Samples. Cell Physiol Biochem 2021; 55:553-568. [PMID: 34599650 DOI: 10.33594/000000435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2021] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND/AIMS Maintenance of whole-body ascorbate levels and distribution is mediated via sodium-dependent vitamin C transporters (SVCTs). The kidney is one of a few organs that express both SVCT1 and SVCT2. Recent evidence suggests that accumulation of ascorbate may be different in tumour compared to normal tissue, but data on SVCT levels in tumours is sparse. METHODS The role of the two SVCT isoforms in ascorbate uptake in renal cell carcinoma (RCC) was investigated in vitro and in clinical samples. In three human RCC cell lines, we investigated SVCT protein levels and cellular location in response to ascorbate supplementation and withdrawal. In clinical RCC samples (n=114), SVCT patterns of staining and protein levels were analysed and compared to ascorbate levels. RESULTS In cell culture, transporter levels and cellular location were not modified by ascorbate availability at any time up to 8h, although basal SVCT2 levels governed maximal ascorbate accumulation. In clinical samples, SVCT1 protein levels in papillary RCC (pRCC) were similar to matched normal renal cortex, but were increased in clear-cell RCC (ccRCC). Native SVCT2 (72 kDa) was significantly decreased in both pRCC and ccRCC tissues compared to cortex (p<0.01), whereas a modified form of SVCT2 (100 kDa) was significantly increased (p<0.001). There was no association between the transporters (SVCT1, native or modified SVCT2) and ascorbate concentrations in either normal or tumour tissues. SVCT1 and SVCT2 displayed diffuse cytoplasmic staining in both pRCC and ccRCC tumour cells, with cortex showing distinct membrane staining for SVCT1. CONCLUSION We observed a re-distribution of ascorbate transporters in tumour tissue compared to normal cortex and a shift from native to modified SVCT2 in cell culture and clinical samples. Data presented here show that SVCT protein levels do not appear to predict intracellular ascorbate accumulation in RCC.
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Affiliation(s)
- Christina Wohlrab
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand.,Fianostics GmbH, Technologie- und Forschungszentrum, Wiener Neustadt, Austria
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Eleanor R Burgess
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Maria Nonis
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Elisabeth Phillips
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Bridget A Robinson
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand.,Canterbury Regional Cancer and Hematology Service, Canterbury District Health Board, Christchurch, New Zealand
| | - Gabi U Dachs
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand,
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15
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Smith-Díaz CC, Magon NJ, McKenzie JL, Hampton MB, Vissers MCM, Das AB. Ascorbate Inhibits Proliferation and Promotes Myeloid Differentiation in TP53-Mutant Leukemia. Front Oncol 2021; 11:709543. [PMID: 34497762 PMCID: PMC8419345 DOI: 10.3389/fonc.2021.709543] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/02/2021] [Indexed: 11/26/2022] Open
Abstract
Loss-of-function mutations in the DNA demethylase TET2 are associated with the dysregulation of hematopoietic stem cell differentiation and arise in approximately 10% of de novo acute myeloid leukemia (AML). TET2 mutations coexist with other mutations in AML, including TP53 mutations, which can indicate a particularly poor prognosis. Ascorbate can function as an epigenetic therapeutic in pathological contexts involving heterozygous TET2 mutations by restoring TET2 activity. How this response is affected when myeloid leukemia cells harbor mutations in both TET2 and TP53 is unknown. Therefore, we examined the effects of ascorbate on the SKM-1 AML cell line that has mutated TET2 and TP53. Sustained treatment with ascorbate inhibited proliferation and promoted the differentiation of these cells. Furthermore, ascorbate treatment significantly increased 5-hydroxymethylcytosine, suggesting increased TET activity as the likely mechanism. We also investigated whether ascorbate affected the cytotoxicity of Prima-1Met, a drug that reactivates some p53 mutants and is currently in clinical trials for AML. We found that the addition of ascorbate had a minimal effect on Prima-1Met–induced cytotoxicity, with small increases or decreases in cytotoxicity being observed depending on the timing of treatment. Collectively, these data suggest that ascorbate could exert a beneficial anti-proliferative effect on AML cells harboring both TET2 and TP53 mutations whilst not interfering with targeted cytotoxic therapies such as Prima-1Met.
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Affiliation(s)
- Carlos C Smith-Díaz
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Nicholas J Magon
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Judith L McKenzie
- Haematology Research Group, Christchurch Hospital and Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Mark B Hampton
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Andrew B Das
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
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16
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Burgess ER, Crake RLI, Phillips E, Morrin HR, Royds JA, Vissers MCM, Robinson BA, Dachs GU. P16.11 Vitamin C levels and the hypoxic pathway in human glioma tissues. Neuro Oncol 2021. [DOI: 10.1093/neuonc/noab180.201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
BACKGROUND
Gliomas are the most common brain cancer and survival is poor, with 11–15 months for high-grade glioblastoma patients, despite treatment. Gliomas are hypoxic tumours, which increases with tumour grade. Under hypoxia, the transcription factor hypoxia inducible factor-1 (HIF) accumulates and upregulates expression of genes involved in tumour development and progression. HIF-1 levels and activity are controlled by HIF hydroxylases which target HIF-1α for degradation and prevent co-activation. HIF hydroxylases are part of the 2-oxoglutarate (2-OG)-dependent dioxygenase enzyme family, that require 2-OG and oxygen as substrates and ascorbate and iron as co-factors. The role of ascorbate in regulating the hypoxic pathway in cancer is of interest, with previous research showing reduced HIF pathway activity with increasing tumour ascorbate levels. Brain tissue has one of the highest ascorbate levels in the body, and is one of the last to become depleted under deficiency, indicating an important role for ascorbate in this tissue. One previous study has analysed ascorbate levels in 11 human glioblastoma patients, and showed lower ascorbate in tumour tissue compared to normal brain tissue. There have been no studies investigating the relationship between ascorbate levels and the hypoxic pathway in human glioma tissues.
MATERIAL AND METHODS
Human glioma tissues (n = 39), obtained from the Cancer Society Tissue Bank Christchurch (ethics approval H19/163), were processed for ascorbate and hypoxic pathway proteins (HIF-1α, CA-IX, BNIP3, HKII, GLUT1 and VEGF). Ascorbate levels were quantified by HPLC-ED, and proteins were measured by Western blotting and ELISA. Spearman’s correlations were used to identify relationships between ascorbate and HIF pathway proteins.
RESULTS
Of the samples, 64% were GBM. Ascorbate was significantly lower in GBM compared to low-grade gliomas (p = 0.04). VEGF was significantly higher in GBM compared to astrocytomas (p = 0.01). Increased tumour ascorbate was associated with lower VEGF and CA-IX proteins. HIF-1α and BNIP3 protein were positively associated, and VEGF was positively associated with HKII and CA-IX. VEGF inversely associated with BNIP3, and CA-IX inversely associated with HKII. The hypoxic pathway score (calculated from protein levels of members of the hypoxic pathway) was reduced in tumours with higher ascorbate but this did not reach significance (p = 0.2).
CONCLUSION
This is the first study to show that ascorbate levels were reduced in high-grade gliomas compared to low-grade. Some members of the hypoxic pathway were associated with ascorbate levels. The overall hypoxic pathway score did not significantly correlate with ascorbate and increased numbers of samples are required to confirm any associations. Other variables, such as IDH-1 mutation status of the tumours may affect the correlation and will be analysed next.
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Affiliation(s)
- E R Burgess
- University of Otago Christchurch, CHRISTCHURCH, New Zealand
| | - R L I Crake
- University of Otago Christchurch, CHRISTCHURCH, New Zealand
| | - E Phillips
- University of Otago Christchurch, CHRISTCHURCH, New Zealand
| | - H R Morrin
- Cancer Society Tissue Bank, University of Otago, CHRISTCHURCH, New Zealand
| | - J A Royds
- University of Otago Christchurch, CHRISTCHURCH, New Zealand
| | - M C M Vissers
- University of Otago Christchurch, CHRISTCHURCH, New Zealand
| | - B A Robinson
- University of Otago Christchurch, CHRISTCHURCH, New Zealand
- Canterbury Regional Cancer and Hematology Service, Christchurch, New Zealand
| | - G U Dachs
- University of Otago Christchurch, CHRISTCHURCH, New Zealand
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17
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Crake RLI, Burgess ER, Royds JA, Phillips E, Vissers MCM, Dachs GU. The Role of 2-Oxoglutarate Dependent Dioxygenases in Gliomas and Glioblastomas: A Review of Epigenetic Reprogramming and Hypoxic Response. Front Oncol 2021; 11:619300. [PMID: 33842321 PMCID: PMC8027507 DOI: 10.3389/fonc.2021.619300] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 01/25/2021] [Indexed: 12/30/2022] Open
Abstract
Gliomas are a heterogeneous group of cancers that predominantly arise from glial cells in the brain, but may also arise from neural stem cells, encompassing low-grade glioma and high-grade glioblastoma. Whereas better diagnosis and new treatments have improved patient survival for many cancers, glioblastomas remain challenging with a highly unfavorable prognosis. This review discusses a super-family of enzymes, the 2-oxoglutarate dependent dioxygenase enzymes (2-OGDD) that control numerous processes including epigenetic modifications and oxygen sensing, and considers their many roles in the pathology of gliomas. We specifically describe in more detail the DNA and histone demethylases, and the hypoxia-inducible factor hydroxylases in the context of glioma, and discuss the substrate and cofactor requirements of the 2-OGDD enzymes. Better understanding of how these enzymes contribute to gliomas could lead to the development of new treatment strategies.
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Affiliation(s)
- Rebekah L. I. Crake
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Eleanor R. Burgess
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Janice A. Royds
- Department of Pathology, University of Otago, Dunedin, New Zealand
| | - Elisabeth Phillips
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Margreet C. M. Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Gabi U. Dachs
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
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18
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Ang AD, Vissers MCM, Burgess ER, Currie MJ, Dachs GU. Gene and Protein Expression Is Altered by Ascorbate Availability in Murine Macrophages Cultured under Tumour-Like Conditions. Antioxidants (Basel) 2021; 10:antiox10030430. [PMID: 33799728 PMCID: PMC7998289 DOI: 10.3390/antiox10030430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/22/2021] [Accepted: 03/09/2021] [Indexed: 01/01/2023] Open
Abstract
Tumour-associated macrophages (TAMs) are ubiquitously present in tumours and commonly associated with poor prognosis. In immune cells, ascorbate affects epigenetic regulation, differentiation and phenotype via its co-factor activity for the 2-oxoglutarate dependent dioxygenase enzymes. Here, we determined the effect of ascorbate on TAM development in response to tumour microenvironmental cues. Naïve murine bone marrow monocytes were cultured with Lewis Lung Carcinoma conditioned media (LLCM) or macrophage colony-stimulating factor (MCSF) to encourage the development into tumour-associated macrophages. Cells were stimulated with hypoxia (1% O2), with or without ascorbate (500 µM) supplementation. Cells and media were harvested for gene, cell surface marker and protein analyses. LLCM supported bone marrow monocyte growth with >90% of cells staining CD11b+F4/80+, indicative of monocytes/macrophages. LLCM-grown cells showed increased expression of M2-like and TAM genes compared to MCSF-grown cells, which further increased with hypoxia. In LLCM-grown cells, ascorbate supplementation was associated with increased F4/80 cell surface expression, and altered gene expression and protein secretion. Our study shows that ascorbate modifies monocyte phenotype when grown under tumour microenvironmental conditions, but this was not clearly associated with either a pro- or anti-tumour phenotype, and reflects a complex and nuanced response of macrophages to ascorbate. Overall, ascorbate supplementation clearly has molecular consequences for TAMs, but functional and clinical consequences remain unknown.
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Affiliation(s)
- Abel D. Ang
- Mackenzie Cancer Research Group, Department of Pathology & Biomedical Science, University of Otago Christchurch, Christchurch 8140, New Zealand; (A.D.A.); (E.R.B.); (M.J.C.)
| | - Margreet C. M. Vissers
- Centre for Free Radical Research, Department of Pathology & Biomedical Science, University of Otago Christchurch, Christchurch 8140, New Zealand;
| | - Eleanor R. Burgess
- Mackenzie Cancer Research Group, Department of Pathology & Biomedical Science, University of Otago Christchurch, Christchurch 8140, New Zealand; (A.D.A.); (E.R.B.); (M.J.C.)
| | - Margaret J. Currie
- Mackenzie Cancer Research Group, Department of Pathology & Biomedical Science, University of Otago Christchurch, Christchurch 8140, New Zealand; (A.D.A.); (E.R.B.); (M.J.C.)
| | - Gabi U. Dachs
- Mackenzie Cancer Research Group, Department of Pathology & Biomedical Science, University of Otago Christchurch, Christchurch 8140, New Zealand; (A.D.A.); (E.R.B.); (M.J.C.)
- Correspondence:
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19
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Fletcher BD, Flett JAM, Wickham SR, Pullar JM, Vissers MCM, Conner TS. Initial Evidence of Variation by Ethnicity in the Relationship between Vitamin C Status and Mental States in Young Adults. Nutrients 2021; 13:792. [PMID: 33673717 PMCID: PMC7997165 DOI: 10.3390/nu13030792] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/17/2021] [Accepted: 02/24/2021] [Indexed: 12/21/2022] Open
Abstract
Higher fruit and vegetable intake has been associated with improved mood, greater vitality, and lower stress. Although the nutrients driving these benefits are not specifically identified, one potentially important micronutrient is vitamin C, an important co-factor for the production of peptide hormones, carnitine and neurotransmitters that are involved in regulation of physical energy and mood. The aim of our study was to investigate the cross-sectional relationship between blood plasma vitamin C status and mood, vitality and perceived stress. A sample of 419 university students (aged 18 to 35; 67.8% female) of various ethnicities (49.2% European, 16.2% East Asian, 8.1% Southeast/Other Asian, 9.1% Māori/Pasifika, 11.5% Other) provided a fasting blood sample to determine vitamin C status and completed psychological measures consisting of the Profile of Mood States Short Form (POMS-SF), the vitality subscale of the Rand 36-Item Short Form (SF-36), and the Perceived Stress Scale (PSS). Participants were screened for prescription medication, smoking history, vitamin C supplementation, fruit/juice and vegetable consumption, kiwifruit allergies, excessive alcohol consumption and serious health issues, and provided age, gender, ethnicity, and socioeconomic status information, which served as covariates. There were no significant associations between vitamin C status and the psychological measures for the sample overall. However, associations varied by ethnicity. Among Māori/Pasifika participants, higher vitamin C was associated with greater vitality and lower stress, whereas among Southeast Asian participants, higher vitamin C was associated with greater confusion on the POMS-SF subscale. These novel findings demonstrate potential ethnicity-linked differences in the relationship between vitamin C and mental states. Further research is required to determine whether genetic variation or cultural factors are driving these ethnicity differences.
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Affiliation(s)
- Benjamin D. Fletcher
- Department of Psychology, University of Otago, Dunedin 9016, New Zealand; (B.D.F.); (S.-R.W.)
| | | | - Shay-Ruby Wickham
- Department of Psychology, University of Otago, Dunedin 9016, New Zealand; (B.D.F.); (S.-R.W.)
| | - Juliet M. Pullar
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8011, New Zealand; (J.M.P.); (M.C.M.V.)
| | - Margreet C. M. Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch 8011, New Zealand; (J.M.P.); (M.C.M.V.)
| | - Tamlin S. Conner
- Department of Psychology, University of Otago, Dunedin 9016, New Zealand; (B.D.F.); (S.-R.W.)
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Dachs GU, Gandhi J, Wohlrab C, Carr AC, Morrin HR, Pullar JM, Bayer SB, Eglinton TW, Robinson BA, Vissers MCM. Vitamin C Administration by Intravenous Infusion Increases Tumor Ascorbate Content in Patients With Colon Cancer: A Clinical Intervention Study. Front Oncol 2021; 10:600715. [PMID: 33505915 PMCID: PMC7830882 DOI: 10.3389/fonc.2020.600715] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/24/2020] [Indexed: 12/12/2022] Open
Abstract
The use of high dose ascorbate infusions in cancer patients is widespread, but without evidence of efficacy. Several mechanisms whereby ascorbate could affect tumor progression have been proposed, including: (i) the localized generation of cytotoxic quantities of H2O2; (ii) ascorbate-dependent activation of the 2-oxoglutarate-dependent dioxygenases that control the hypoxia-inducible factors (HIFs) and that are responsible for the demethylation of DNA and histones; (iii) increased oxidative stress induced by dehydroascorbic acid. We hypothesize that the dysfunctional vasculature of solid tumors results in compromised delivery of ascorbate to poorly perfused regions of the tumor and that this ascorbate deficit acts as an additional driver of the hypoxic response via upregulation of HIFs. Using a randomized “therapeutic window of opportunity” clinical study design we aimed to determine whether ascorbate infusions affected tumor ascorbate content and tumor biology. Patients with colon cancer were randomized to receive infusions of up to 1 g/kg ascorbate for 4 days before surgical resection (n = 9) or to not receive infusions (n = 6). Ascorbate was measured in plasma, erythrocytes, tumor and histologically normal mucosa at diagnostic colonoscopy and at surgery. Protein markers of tumor hypoxia or DNA damage were monitored in resected tissue. Plasma ascorbate reached millimolar levels following infusion and returned to micromolar levels over 24 h. Pre-infusion plasma ascorbate increased from 38 ± 10 µM to 241 ± 33 µM (p < 0.0001) over 4 days and erythrocyte ascorbate from 18 ± 20 µM to 2509 ± 1016 µM (p < 0.005). Tumor ascorbate increased from 15 ± 6 to 28 ± 6 mg/100 g tissue (p < 0.0001) and normal tissue from 14 ± 6 to 21 ± 4 mg/100 g (p < 0.001). A gradient of lower ascorbate was evident towards the tumor centre in both control and infusion samples. Lower expression of hypoxia-associated proteins was seen in post-infusion tumors compared with controls. There were no significant adverse events and quality of life was unaffected by ascorbate infusion. This is the first clinical study to demonstrate that tumor ascorbate levels increase following infusion, even in regions of poor diffusion, and that this could modify tumor biology.
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Affiliation(s)
- Gabi U Dachs
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Jamish Gandhi
- Department of Surgery, Christchurch Hospital, University of Otago Christchurch, Christchurch, New Zealand
| | - Christina Wohlrab
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Anitra C Carr
- Nutrition in Medicine Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Helen R Morrin
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand.,Cancer Society Tissue Bank, University of Otago Christchurch, Christchurch, New Zealand
| | - Juliet M Pullar
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Simone B Bayer
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Tim W Eglinton
- Department of Surgery, Christchurch Hospital, University of Otago Christchurch, Christchurch, New Zealand
| | - Bridget A Robinson
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand.,Canterbury Regional Cancer and Haematology Service, Canterbury District Health Board, Department of Medicine, University of Otago Christchurch, Christchurch, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
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21
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Das AB, Smith-Díaz CC, Vissers MCM. Emerging epigenetic therapeutics for myeloid leukemia: modulating demethylase activity with ascorbate. Haematologica 2021; 106:14-25. [PMID: 33099992 PMCID: PMC7776339 DOI: 10.3324/haematol.2020.259283] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/17/2020] [Indexed: 12/23/2022] Open
Abstract
The past decade has seen a proliferation of drugs that target epigenetic pathways. Many of these drugs were developed to treat acute myeloid leukemia, a condition in which dysregulation of the epigenetic landscape is well established. While these drugs have shown promise, critical issues persist. Specifically, patients with the same mutations respond quite differently to treatment. This is true even with highly specific drugs that are designed to target the underlying oncogenic driver mutations. Furthermore, patients who do respond may eventually develop resistance. There is now evidence that epigenetic heterogeneity contributes, in part, to these issues. Cancer cells also have a remarkable capacity to ‘rewire’ themselves at the epigenetic level in response to drug treatment, and thereby maintain expression of key oncogenes. This epigenetic plasticity is a promising new target for drug development. It is therefore important to consider combination therapy in cases in which both driver mutations and epigenetic plasticity are targeted. Using ascorbate as an example of an emerging epigenetic therapeutic, we review the evidence for its potential use in both of these modes. We provide an overview of 2-oxoglutarate dependent dioxygenases with DNA, histone and RNA demethylase activity, focusing on those which require ascorbate as a cofactor. We also evaluate their role in the development and maintenance of acute myeloid leukemia. Using this information, we highlight situations in which the use of ascorbate to restore 2-oxoglutarate dependent dioxygenase activity could prove beneficial, in contrast to contexts in which targeted inhibition of specific enzymes might be preferred. Finally, we discuss how these insights could be incorporated into the rational design of future clinical trials.
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Affiliation(s)
- Andrew B Das
- Department of Pathology and Biomedical Science, University of Otago, Christchurch.
| | - Carlos C Smith-Díaz
- Department of Pathology and Biomedical Science, University of Otago, Christchurch
| | - Margreet C M Vissers
- Department of Pathology and Biomedical Science, University of Otago, Christchurch
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22
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White R, Nonis M, Pearson JF, Burgess E, Morrin HR, Pullar JM, Spencer E, Vissers MCM, Robinson BA, Dachs GU. Low Vitamin C Status in Patients with Cancer Is Associated with Patient and Tumor Characteristics. Nutrients 2020; 12:nu12082338. [PMID: 32764253 PMCID: PMC7468872 DOI: 10.3390/nu12082338] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 12/16/2022] Open
Abstract
Vitamin C (ascorbate) acts as an antioxidant and enzyme cofactor, and plays a vital role in human health. Vitamin C status can be affected by illness, with low levels being associated with disease due to accelerated turnover. However, robust data on the ascorbate status of patients with cancer are sparse. This study aimed to accurately measure ascorbate concentrations in plasma from patients with cancer, and determine associations with patient or tumor characteristics. We recruited 150 fasting patients with cancer (of 199 total recruited) from two cohorts, either prior to cancer surgery or during cancer chemo- or immunotherapy. A significant number of patients with cancer had inadequate plasma ascorbate concentrations. Low plasma status was more prevalent in patients undergoing cancer therapy. Ascorbate status was higher in women than in men, and exercising patients had higher levels than sedentary patients. Our study may prompt increased vigilance of ascorbate status in cancer patients.
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Affiliation(s)
- Rebecca White
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand; (R.W.); (M.N.); (E.B.); (H.R.M.); (B.A.R.)
| | - Maria Nonis
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand; (R.W.); (M.N.); (E.B.); (H.R.M.); (B.A.R.)
| | - John F. Pearson
- Biostatistics and Computational Biology Unit, University of Otago Christchurch, Christchurch 8011, New Zealand;
| | - Eleanor Burgess
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand; (R.W.); (M.N.); (E.B.); (H.R.M.); (B.A.R.)
| | - Helen R. Morrin
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand; (R.W.); (M.N.); (E.B.); (H.R.M.); (B.A.R.)
- Cancer Society Tissue Bank, University of Otago Christchurch, Christchurch 8011, New Zealand
| | - Juliet M. Pullar
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand; (J.M.P.); (M.C.M.V.)
| | - Emma Spencer
- Nutrition in Medicine Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand;
| | - Margreet C. M. Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand; (J.M.P.); (M.C.M.V.)
| | - Bridget A. Robinson
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand; (R.W.); (M.N.); (E.B.); (H.R.M.); (B.A.R.)
- Canterbury Regional Cancer and Hematology Service, Canterbury District Health Board, and Department of Medicine, University of Otago Christchurch, Christchurch 8011, New Zealand
| | - Gabi U. Dachs
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch 8011, New Zealand; (R.W.); (M.N.); (E.B.); (H.R.M.); (B.A.R.)
- Correspondence: ; Tel.: +64-3-3640544
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23
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Das AB, Kakadia PM, Wojcik D, Pemberton L, Browett PJ, Bohlander SK, Vissers MCM. Clinical remission following ascorbate treatment in a case of acute myeloid leukemia with mutations in TET2 and WT1. Blood Cancer J 2019; 9:82. [PMID: 31578317 PMCID: PMC6775073 DOI: 10.1038/s41408-019-0242-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 09/06/2019] [Accepted: 09/17/2019] [Indexed: 12/21/2022] Open
Affiliation(s)
- Andrew B Das
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, Christchurch, New Zealand
| | - Purvi M Kakadia
- Leukaemia & Blood Cancer Research Unit, Department of Molecular Medicine and Pathology, The University of Auckland, Auckland, New Zealand
| | - Damian Wojcik
- Northland Environmental Health Clinic, 2 Dip Rd, Kamo, Whangarei, New Zealand
| | - Lucy Pemberton
- Southern Blood and Cancer Service, Southern District Health Board, Dunedin Hospital, Dunedin, New Zealand
| | - Peter J Browett
- Leukaemia & Blood Cancer Research Unit, Department of Molecular Medicine and Pathology, The University of Auckland, Auckland, New Zealand
| | - Stefan K Bohlander
- Leukaemia & Blood Cancer Research Unit, Department of Molecular Medicine and Pathology, The University of Auckland, Auckland, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, Christchurch, New Zealand.
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Tang JS, Bozonet SM, McKenzie JL, Anderson RF, Melton LD, Vissers MCM. Back Cover: Physiological Concentrations of Blueberry‐Derived Phenolic Acids Reduce Monocyte Adhesion to Human Endothelial Cells. Mol Nutr Food Res 2019. [DOI: 10.1002/mnfr.201970047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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25
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Talla U, Bozonet SM, Parker HA, Hampton MB, Vissers MCM. Prolonged exposure to hypoxia induces an autophagy-like cell survival program in human neutrophils. J Leukoc Biol 2019; 106:1367-1379. [PMID: 31412152 DOI: 10.1002/jlb.4a0319-079rr] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 07/14/2019] [Accepted: 07/14/2019] [Indexed: 12/13/2022] Open
Abstract
Neutrophils contribute to low oxygen availability at inflammatory sites through the generation of reactive oxidants. They are also functionally affected by hypoxia, which delays neutrophil apoptosis. However, the eventual fate of neutrophils in hypoxic conditions is unknown and this is important for their effective clearance and the resolution of inflammation. We have monitored the survival and function of normal human neutrophils exposed to hypoxia over a 48 h period. Apoptosis was delayed, and the cells remained intact even at 48 h. However, hypoxia promoted significant changes in neutrophil morphology with the appearance of many new cytoplasmic vesicles, often containing cell material, within 5 hours of exposure to low O2 . This coincided with an increase in LC3B-II expression, indicative of autophagosome formation and an autophagy-like process. In hypoxic conditions, neutrophils preferentially lost myeloperoxidase, a marker of azurophil granules. Short-term (2 h) hypoxic exposure resulted in sustained potential to generate superoxide when O2 was restored, but the capacity for oxidant production was lost with longer periods of hypoxia. Phagocytic ability was unchanged by hypoxia, and bacterial killing by neutrophils in both normoxic and hypoxic conditions was substantially diminished after 24 hours. However, pre-exposure to hypoxia resulted in an enhanced ability to kill bacteria by oxidant-independent mechanisms. Our data provide the first evidence for hypoxia as a driver of neutrophil autophagy that can influence the function and ultimate fate of these cells, including their eventual clearance and the resolution of inflammation.
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Affiliation(s)
- Usharani Talla
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Stephanie M Bozonet
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Heather A Parker
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Mark B Hampton
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
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26
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Tang JS, Bozonet SM, McKenzie JL, Anderson RF, Melton LD, Vissers MCM. Physiological Concentrations of Blueberry-Derived Phenolic Acids Reduce Monocyte Adhesion to Human Endothelial Cells. Mol Nutr Food Res 2019; 63:e1900478. [PMID: 31216087 DOI: 10.1002/mnfr.201900478] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Indexed: 12/12/2022]
Abstract
SCOPE Blueberry polyphenols are thought to confer cardiovascular health benefits, but have limited bioavailability. They undergo extensive metabolism and their phenolic acid metabolites are likely to be the mediators of bioactivity. The effect of blueberry-derived phenolic acids on one aspect of inflammation, monocyte adhesion to vascular endothelial cells, is investigated. METHODS AND RESULTS The major blueberry-derived phenolic acids in human plasma are identified and quantified. Three test mixtures representing compounds present at 0-4 h (Early), 4-24 h (Late), or 0-24 h (Whole) are used to investigate the effect on adhesion of monocytes to tumor necrosis factor alpha (TNFα)-activated endothelial cells. The Late mixture reduces monocyte adhesion, but there is no effect of the Early or Whole mixtures. Exclusion of syringic acid from each mixture results in inhibition of monocyte adhesion. Exposure to the phenolic acid mixtures has no effect on the endothelial surface expression of adhesion molecules intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), or E-selectin, suggesting that other molecular mechanisms are responsible for the observed effect. CONCLUSION This study shows that physiological concentrations of blueberry polyphenol metabolites can help maintain cardiovascular health by regulating monocyte adhesion to the vascular endothelium.
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Affiliation(s)
- Jeffry S Tang
- School of Chemical Sciences, University of Auckland, Auckland, 1142, New Zealand.,Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, 8011, New Zealand
| | - Stephanie M Bozonet
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, 8011, New Zealand
| | - Judith L McKenzie
- Hematology Research Group, Department of Pathology & Biomedical Science, University of Otago, Christchurch, 8011, New Zealand
| | - Robert F Anderson
- School of Chemical Sciences, University of Auckland, Auckland, 1142, New Zealand.,Faculty of Medical and Health Sciences, Auckland Cancer Society Research Centre, University of Auckland, Auckland, 1023, New Zealand
| | - Laurence D Melton
- School of Chemical Sciences, University of Auckland, Auckland, 1142, New Zealand.,Riddet Centre of Research Excellence for Food Research, Palmerston North, 4442, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, 8011, New Zealand
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Campbell EJ, Dachs GU, Morrin HR, Davey VC, Robinson BA, Vissers MCM. Activation of the hypoxia pathway in breast cancer tissue and patient survival are inversely associated with tumor ascorbate levels. BMC Cancer 2019; 19:307. [PMID: 30943919 PMCID: PMC6448303 DOI: 10.1186/s12885-019-5503-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 03/21/2019] [Indexed: 12/21/2022] Open
Abstract
Background The transcription factor hypoxia inducible factor (HIF) -1 drives tumor growth and metastasis and is associated with poor prognosis in breast cancer. Ascorbate can moderate HIF-1 activity in vitro and is associated with HIF pathway activation in a number of cancer types, but whether tissue ascorbate levels influence the HIF pathway in breast cancer is unknown. In this study we investigated the association between tumor ascorbate levels and HIF-1 activation and patient survival in human breast cancer. Methods In a retrospective analysis of human breast cancer tissue, we analysed primary tumor and adjacent uninvolved tissue from 52 women with invasive ductal carcinoma. We measured HIF-1α, HIF-1 gene targets CAIX, BNIP-3 and VEGF, and ascorbate content. Patient clinical outcomes were evaluated against these parameters. Results HIF-1 pathway proteins were upregulated in tumor tissue and increased HIF-1 activation was associated with higher tumor grade and stage, with increased vascular invasion and necrosis, and with decreased disease-free and disease-specific survival. Grade 1 tumors had higher ascorbate levels than did grade 2 or 3 tumors. Higher ascorbate levels were associated with less tumor necrosis, with lower HIF-1 pathway activity and with increased disease-free and disease-specific survival. Conclusions Our findings indicate that there is a direct correlation between intracellular ascorbate levels, activation of the HIF-1 pathway and patient survival in breast cancer. This is consistent with the known capacity of ascorbate to stimulate the activity of the regulatory HIF hydroxylases and suggests that optimisation of tumor ascorbate could have clinical benefit via modulation of the hypoxic response.
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Affiliation(s)
- Elizabeth J Campbell
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, 8011, New Zealand.,Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, 8140, New Zealand
| | - Gabi U Dachs
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, 8011, New Zealand
| | - Helen R Morrin
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, 8011, New Zealand.,Cancer Society Tissue Bank, University of Otago, Christchurch, 8011, New Zealand
| | - Valerie C Davey
- Christchurch Breast Cancer Patient Register, Christchurch Hospital, Christchurch, 8011, New Zealand
| | - Bridget A Robinson
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, 8011, New Zealand.,Canterbury Regional Cancer and Haematology Service, Canterbury District Health Board, Christchurch, and Department of Medicine, University of Otago, Christchurch, 8011, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, 8140, New Zealand.
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Wohlrab C, Vissers MCM, Phillips E, Morrin H, Robinson BA, Dachs GU. The Association Between Ascorbate and the Hypoxia-Inducible Factors in Human Renal Cell Carcinoma Requires a Functional Von Hippel-Lindau Protein. Front Oncol 2018; 8:574. [PMID: 30555801 PMCID: PMC6284050 DOI: 10.3389/fonc.2018.00574] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 11/15/2018] [Indexed: 12/11/2022] Open
Abstract
Hypoxia-inducible transcription factors (HIFs) drive angiogenesis and cancer cell growth, contributing to an aggressive tumor phenotype. HIF-α protein levels and activity are controlled at the post-translational level by HIF hydroxylases. Hydroxylated HIF-α is recognized by the von Hippel Lindau (VHL) tumor suppressor and targeted for degradation. The HIF hydroxylases are members of the iron and 2-oxoglutarate-dependent dioxygenases, which require ascorbate as cofactor for activity. Clear cell renal cell carcinomas (ccRCC) harbor mutations in the VHL gene, whereas papillary RCC (pRCC) have a functional VHL. These natural occurring VHL variants in RCC enable the testing, in clinical samples, of the hypothesis that ascorbate modulates HIF-α levels through its role as a cofactor for the HIF hydroxylases. We measured ascorbate, HIF-1α, and HIF-2α protein and HIF downstream targets BNIP3, CA9, cyclin D1, GLUT1, and VEGF (combined to generate the HIF pathway score) in VHL-defective ccRCC (n = 73) and VHL-proficient pRCC human tumor tissue (n = 41). HIF and ascorbate levels were increased in ccRCC and pRCC tumors compared to matched renal cortex. HIF-1 and total HIF pathway activation scores were decreased with higher ascorbate in pRCC tumors (Spearman r = −0.38, p < 0.05 and r = −0.35, p < 0.05). This was not evident for ccRCC tumors. In mechanistic studies in vitro, ascorbate influenced HIF-1 activity in VHL-proficient, but not VHL-defective ccRCC cells. Our results indicate that ccRCC, which lacks a functional VHL, does not respond to ascorbate-mediated modulation of the HIF response. This contrasts with the demonstrated association between ascorbate content and the HIF pathway observed in pRCC and other tumors with a functional VHL. The results support a role for ascorbate as a modulator of HIF activity and tumor aggression in cancer types with a functional hypoxic response.
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Affiliation(s)
- Christina Wohlrab
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Elisabeth Phillips
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Helen Morrin
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand.,Cancer Society Tissue Bank, University of Otago, Christchurch, New Zealand
| | - Bridget A Robinson
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand.,Canterbury Regional Cancer and Haematology Service, Canterbury District Health Board, Christchurch Hospital, Christchurch, New Zealand
| | - Gabi U Dachs
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
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Abstract
Whether vitamin C (ascorbate) has a role to play as an anti-cancer agent has been debated for decades. Ascorbate has been used by cancer patients in an unregulated environment, either as a dietary supplement or in pharmacological doses administered by infusion, with numerous reports of clinical benefit, but in the absence of rigorous clinical trial data. The design of appropriate clinical trials has been hindered by a lack of understanding of the mechanism(s) of action that would inform the choice of effective dose, timing of administration and likely responsive cancer models. More recently, expanded understanding of the biological activities of ascorbate has led to a number of plausible hypotheses for mechanisms of anti-cancer activity. Prominent among these are the generation of significant quantities of hydrogen peroxide by the autoxidation of supra-physiological concentrations of ascorbate and stimulation of the 2-oxoglutarate-dependent dioxygenase family of enzymes (2-OGDDs) that have a cofactor requirement for ascorbate. Hydrogen peroxide generation is postulated to generate oxidative stress that preferentially targets cancer cells. The 2-OGDDs include the hydroxylases that regulate the hypoxic response, a major driver of tumor survival, angiogenesis, stem cell phenotype and metastasis, and the epigenetic histone and DNA demethylases. The latter are of particular interest, with recent studies suggesting a promising role for ascorbate in the regulation of the ten-eleven translocase (TET) DNA demethylases in hematological cancers. Support for these proposed mechanisms has come from many in vitro studies, and xenograft animal models have consistently shown an anti-cancer effect of ascorbate administration. However, decisive evidence for any particular mechanism(s) of action is not yet available from an in vivo setting. With a number of early phase clinical trials currently underway, evidence for potential mechanism(s) of action is required to inform the most appropriate study design and choice of cancer model. Hopefully such information will result in sound clinical data that will avert adding any further controversy to this already contentious debate.
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Affiliation(s)
- Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, Christchurch, New Zealand
| | - Andrew B Das
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, Christchurch, New Zealand
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Tang JS, Vissers MCM, Anderson RF, Sreebhavan S, Bozonet SM, Scheepens A, Melton LD. Bioavailable Blueberry-Derived Phenolic Acids at Physiological Concentrations Enhance Nrf2-Regulated Antioxidant Responses in Human Vascular Endothelial Cells. Mol Nutr Food Res 2018; 62. [PMID: 29278300 DOI: 10.1002/mnfr.201700647] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 12/15/2017] [Indexed: 12/13/2022]
Abstract
SCOPE Blueberry consumption is believed to confer a cardiovascular health advantage, but the active compounds and effects require characterization. This study aims to identify the polyphenol metabolites in plasma after blueberry juice intake and determine their bioactivity on endothelial cells. METHODS AND RESULTS Three healthy individuals are recruited to obtain profiles of bioavailable plasma polyphenol metabolites following intake of blueberry juice. Of 33 phenolic compounds screened, 12 aglycone phenolic acids are detected and their maximum plasma concentrations and circulation time determined. Using this information, the effect of three physiologically relevant mixtures of blueberry-derived phenolic acids is investigated for their ability to induce nuclear factor erythroid 2-related factor 2 (Nrf2)-nuclear translocation and downstream gene expression in human endothelial cells. Pretreatment with the phenolic acids for 18 h results in a significant upregulation of the Nrf2-regulated antioxidant response proteins heme oxygenase 1 (HO-1) and glutamate-cysteine ligase modifier subunit (GCLM), following 6 h exposure to 2.5 μm H2 O2 . CONCLUSION Physiologically relevant concentrations of blueberry-derived aglycone phenolic acids can induce Nrf2-regulated antioxidant response proteins in vascular endothelial cells in response to low μm concentrations of H2 O2 . Our results represent an advance over previous studies that have used single compounds or high concentrations in cell-based investigations.
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Affiliation(s)
- Jeffry S Tang
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand
| | - Robert F Anderson
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand.,Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, University of Auckland, Aukland, New Zealand
| | - Sreevalsan Sreebhavan
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, University of Auckland, Aukland, New Zealand
| | - Stephanie M Bozonet
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand
| | - Arjan Scheepens
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Laurence D Melton
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand.,Riddet Centre of Research Excellence for Food Research, Palmerston North, New Zealand
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Mitsuya K, Parker AN, Liu L, Ruan J, Vissers MCM, Myatt L. Alterations in the placental methylome with maternal obesity and evidence for metabolic regulation. PLoS One 2017; 12:e0186115. [PMID: 29045485 PMCID: PMC5646778 DOI: 10.1371/journal.pone.0186115] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 09/25/2017] [Indexed: 12/23/2022] Open
Abstract
The inflammatory and metabolic derangements of obesity in pregnant women generate an adverse intrauterine environment, increase pregnancy complications and adverse fetal outcomes and program the fetus for obesity and metabolic syndrome in later life. We hypothesized that epigenetic modifications in placenta including altered DNA methylation/hydroxymethylation may mediate these effects. Term placental villous tissue was collected following cesarean section from lean (prepregnancy BMI<25) or obese (BMI>30) women. Genomic DNA was isolated, methylated and hydroxymethylated DNA immunoprecipitated and hybridized to the NimbleGen 2.1M human DNA methylation array. Intermediate metabolites in placental tissues were measured by HPLC-ESI-MS, ascorbate levels by reverse phase HPLC and gene expression by RT-PCR. Differentially methylated and hydroxymethylated regions occurred across the genome, with a 21% increase in methylated but a 31% decrease in hydroxymethylated regions in obese vs lean groups. Whereas increased methylation and decreased methylation was evident around transcription start sites of multiple genes in the GH/CSH and PSG gene clusters on chromosomes 17 and 19 in other areas there was no relationship. Increased methylation was associated with decreased expression only for some genes in these clusters. Biological pathway analysis revealed the 262 genes which showed reciprocal differential methylation/ hydroxymethylation were enriched for pregnancy, immune response and cell adhesion-linked processes. We found a negative relationship for maternal BMI but a positive relationship for ascorbate with α-ketoglutarate a metabolite that regulates ten eleven translocase (TET) which mediates DNA methylation. We provide evidence for the obese maternal metabolic milieu being linked to an altered DNA methylome that may affect placental gene expression in relation to adverse outcomes.
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Affiliation(s)
- Kohzoh Mitsuya
- Center for Pregnancy and Newborn Research, Department of Obstetrics and Gynecology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Ashley N. Parker
- Center for Pregnancy and Newborn Research, Department of Obstetrics and Gynecology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Lu Liu
- Department of Computer Science, University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Jianhua Ruan
- Department of Computer Science, University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Margreet C. M. Vissers
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand
| | - Leslie Myatt
- Center for Pregnancy and Newborn Research, Department of Obstetrics and Gynecology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- * E-mail:
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Abstract
The primary function of the skin is to act as a barrier against insults from the environment, and its unique structure reflects this. The skin is composed of two layers: the epidermal outer layer is highly cellular and provides the barrier function, and the inner dermal layer ensures strength and elasticity and gives nutritional support to the epidermis. Normal skin contains high concentrations of vitamin C, which supports important and well-known functions, stimulating collagen synthesis and assisting in antioxidant protection against UV-induced photodamage. This knowledge is often used as a rationale for the addition of vitamin C to topical applications, but the efficacy of such treatment, as opposed to optimising dietary vitamin C intake, is poorly understood. This review discusses the potential roles for vitamin C in skin health and summarises the in vitro and in vivo research to date. We compare the efficacy of nutritional intake of vitamin C versus topical application, identify the areas where lack of evidence limits our understanding of the potential benefits of vitamin C on skin health, and suggest which skin properties are most likely to benefit from improved nutritional vitamin C intake.
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Affiliation(s)
- Juliet M Pullar
- Department of Pathology, University of Otago, Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand.
| | - Anitra C Carr
- Department of Pathology, University of Otago, Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand.
| | - Margreet C M Vissers
- Department of Pathology, University of Otago, Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand.
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Conner TS, Brookie KL, Carr AC, Mainvil LA, Vissers MCM. Let them eat fruit! The effect of fruit and vegetable consumption on psychological well-being in young adults: A randomized controlled trial. PLoS One 2017; 12:e0171206. [PMID: 28158239 PMCID: PMC5291486 DOI: 10.1371/journal.pone.0171206] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/05/2017] [Indexed: 01/06/2023] Open
Abstract
This study tested the psychological benefits of a 14-day preregistered clinical intervention to increase fruit and vegetable (FV) consumption in 171 low-FV-consuming young adults (67% female, aged 18–25). Participants were randomly assigned into a diet-as-usual control condition, an ecological momentary intervention (EMI) condition involving text message reminders to increase their FV consumption plus a voucher to purchase FV, or a fruit and vegetable intervention (FVI) condition in which participants were given two additional daily servings of fresh FV to consume on top of their normal diet. Self-report outcome measures were depressive symptoms and anxiety measured pre- and post-intervention, and daily negative and positive mood, vitality, flourishing, and flourishing behaviors (curiosity, creativity, motivation) assessed nightly using a smartphone survey. Vitamin C and carotenoids were measured from blood samples pre- and post-intervention, and psychological expectancies about the benefits of FV were measured post-intervention to test as mediators of psychological change. Only participants in the FVI condition showed improvements to their psychological well-being with increases in vitality, flourishing, and motivation across the 14-days relative to the other groups. No changes were found for depressive symptoms, anxiety, or mood. Intervention benefits were not mediated by vitamin C, carotenoids, or psychological expectancies. We conclude that providing young adults with high-quality FV, rather than reminding them to eat more FV (with a voucher to purchase FV), resulted in significant short-term improvements to their psychological well-being. These results provide initial proof-of-concept that giving young adults fresh fruit and vegetables to eat can have psychological benefits even over a brief period of time. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12615000183583
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Affiliation(s)
- Tamlin S. Conner
- Department of Psychology, University of Otago, Dunedin, Otago, New Zealand
- * E-mail:
| | - Kate L. Brookie
- Department of Psychology, University of Otago, Dunedin, Otago, New Zealand
| | - Anitra C. Carr
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand
| | - Louise A. Mainvil
- Department of Human Nutrition, University of Otago, Dunedin, Otago, New Zealand
| | - Margreet C. M. Vissers
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand
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Campbell EJ, Vissers MCM, Wohlrab C, Hicks KO, Strother RM, Bozonet SM, Robinson BA, Dachs GU. Pharmacokinetic and anti-cancer properties of high dose ascorbate in solid tumours of ascorbate-dependent mice. Free Radic Biol Med 2016; 99:451-462. [PMID: 27567539 DOI: 10.1016/j.freeradbiomed.2016.08.027] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 08/23/2016] [Accepted: 08/23/2016] [Indexed: 12/18/2022]
Abstract
Despite recent evidence for an anti-tumour role for high-dose ascorbate, potential mechanisms of action are still unclear. At mM concentrations that are achieved with high-dose intravenous administration, autoxidation of ascorbate can generate cytotoxic levels of H2O2. Ascorbate is also a required co-factor for the hydroxylases that suppress the transcription factor hypoxia-inducible factor (HIF-1). HIF-1 supports an aggressive tumour phenotype and is associated with poor prognosis, and previous studies have shown that optimizing intracellular ascorbate levels down-regulates HIF-1 activation. In this study we have simultaneously measured ascorbate concentrations and the HIF-1 pathway activity in tumour tissue following high dose ascorbate administration, and have studied tumour growth and physiology. Gulo-/- mice, a model of the human ascorbate dependency condition, were implanted with syngeneic Lewis lung tumours, 1g/kg ascorbate was administered into the peritoneum, and ascorbate concentrations were monitored in plasma, liver and tumours. Ascorbate levels peaked within 30min, and although plasma and liver ascorbate returned to baseline within 16h, tumour levels remained elevated for 48h, possibly reflecting increased stability in the hypoxic tumour environment. The expression of HIF-1 and its target proteins was down-regulated with tumour ascorbate uptake. Elevated tumour ascorbate levels could be maintained with daily administration, and HIF-1 and vascular endothelial growth factor protein levels were reduced in these conditions. Increased tumour ascorbate was associated with slowed tumour growth, reduced tumour microvessel density and decreased hypoxia. Alternate day administration of ascorbate resulted in lower tumour levels and did not consistently decrease HIF-1 pathway activity. Levels of sodium-dependent vitamin C transporters 1 and 2 were not clearly associated with ascorbate accumulation by murine tumour cells in vitro or in vivo. Our results support the suppression of the hypoxic response by ascorbate as a plausible mechanism of action of its anti-tumour activity, and this may be useful in a clinical setting.
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MESH Headings
- Animals
- Antineoplastic Agents/blood
- Antineoplastic Agents/pharmacokinetics
- Antineoplastic Agents/pharmacology
- Antioxidants/metabolism
- Antioxidants/pharmacokinetics
- Antioxidants/pharmacology
- Ascorbic Acid/blood
- Ascorbic Acid/pharmacokinetics
- Ascorbic Acid/pharmacology
- Carcinoma, Lewis Lung/drug therapy
- Carcinoma, Lewis Lung/genetics
- Carcinoma, Lewis Lung/metabolism
- Carcinoma, Lewis Lung/pathology
- Drug Administration Schedule
- Female
- Gene Expression Regulation, Neoplastic
- Hypoxia-Inducible Factor 1, alpha Subunit/antagonists & inhibitors
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Injections, Intraperitoneal
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Mice
- Mice, Knockout
- Signal Transduction
- Sodium-Coupled Vitamin C Transporters/genetics
- Sodium-Coupled Vitamin C Transporters/metabolism
- Vascular Endothelial Growth Factor A/antagonists & inhibitors
- Vascular Endothelial Growth Factor A/genetics
- Vascular Endothelial Growth Factor A/metabolism
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Affiliation(s)
- Elizabeth J Campbell
- Mackenzie Cancer Research Group, Department of Pathology, University of Otago, Christchurch 8011, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch 8011, New Zealand
| | - Christina Wohlrab
- Mackenzie Cancer Research Group, Department of Pathology, University of Otago, Christchurch 8011, New Zealand
| | - Kevin O Hicks
- Auckland Cancer Society Research Centre, University of Auckland, Auckland 1142, New Zealand
| | - R Matthew Strother
- Canterbury Regional Cancer and Haematology Service, Canterbury District Health Board, Christchurch 8011, New Zealand
| | - Stephanie M Bozonet
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch 8011, New Zealand
| | - Bridget A Robinson
- Mackenzie Cancer Research Group, Department of Pathology, University of Otago, Christchurch 8011, New Zealand; Canterbury Regional Cancer and Haematology Service, Canterbury District Health Board, Christchurch 8011, New Zealand; Department of Medicine, University of Otago, Christchurch 8011, New Zealand
| | - Gabi U Dachs
- Mackenzie Cancer Research Group, Department of Pathology, University of Otago, Christchurch 8011, New Zealand.
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Kuiper C, Vissers MCM. Ascorbate as a co-factor for fe- and 2-oxoglutarate dependent dioxygenases: physiological activity in tumor growth and progression. Front Oncol 2014; 4:359. [PMID: 25540771 PMCID: PMC4261134 DOI: 10.3389/fonc.2014.00359] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 11/27/2014] [Indexed: 01/07/2023] Open
Abstract
Ascorbate is a specific co-factor for a large family of enzymes known as the Fe- and 2-oxoglutarate-dependent dioxygenases. These enzymes are found throughout biology and catalyze the addition of a hydroxyl group to various substrates. The proline hydroxylase that is involved in collagen maturation is well known, but in recent times many new enzymes and functions have been uncovered, including those involved in epigenetic control and hypoxia-inducible factor (HIF) regulation. These discoveries have provided crucial mechanistic insights into how ascorbate may affect tumor biology. In particular, there is growing evidence that HIF-1-dependent tumor progression may be inhibited by increasing tumor ascorbate levels. However, rigorous clinical intervention studies are lacking. This review will explore the physiological role of ascorbate as an enzyme co-factor and how this mechanism relates to cancer biology and treatment. The use of ascorbate in cancer should be informed by clinical studies based on such mechanistic hypotheses.
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Affiliation(s)
- Caroline Kuiper
- Department of Pathology, Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
| | - Margreet C. M. Vissers
- Department of Pathology, Centre for Free Radical Research, University of Otago, Christchurch, New Zealand
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36
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Kuiper C, Vissers MCM, Hicks KO. Pharmacokinetic modeling of ascorbate diffusion through normal and tumor tissue. Free Radic Biol Med 2014; 77:340-52. [PMID: 25277418 DOI: 10.1016/j.freeradbiomed.2014.09.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 09/12/2014] [Accepted: 09/19/2014] [Indexed: 01/21/2023]
Abstract
Ascorbate is delivered to cells via the vasculature, but its ability to penetrate into tissues remote from blood vessels is unknown. This is particularly relevant to solid tumors, which often contain regions with dysfunctional vasculature, with impaired oxygen and nutrient delivery, resulting in upregulation of the hypoxic response and also the likely depletion of essential plasma-derived biomolecules, such as ascorbate. In this study, we have utilized a well-established multicell-layered, three-dimensional pharmacokinetic model to measure ascorbate diffusion and transport parameters through dense tissue in vitro. Ascorbate was found to penetrate the tissue at a slightly lower rate than mannitol and to travel via the paracellular route. Uptake parameters into the cells were also determined. These data were fitted to the diffusion model, and simulations of ascorbate pharmacokinetics in normal tissue and in hypoxic tumor tissue were performed with varying input concentrations, ranging from normal dietary plasma levels (10-100 μM) to pharmacological levels (>1 mM) as seen with intravenous infusion. The data and simulations demonstrate heterogeneous distribution of ascorbate in tumor tissue at physiological blood levels and provide insight into the range of plasma ascorbate concentrations and exposure times needed to saturate all regions of a tumor. The predictions suggest that supraphysiological plasma ascorbate concentrations (>100 μM) are required to achieve effective delivery of ascorbate to poorly vascularized tumor tissue.
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Affiliation(s)
- Caroline Kuiper
- Centre for Free Radical Research, Pathology Department, University of Otago at Christchurch, Christchurch, New Zealand.
| | - Margreet C M Vissers
- Centre for Free Radical Research, Pathology Department, University of Otago at Christchurch, Christchurch, New Zealand
| | - Kevin O Hicks
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
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Campbell EJ, Vissers MCM, Bozonet S, Dyer A, Robinson BA, Dachs GU. Restoring physiological levels of ascorbate slows tumor growth and moderates HIF-1 pathway activity in Gulo(-/-) mice. Cancer Med 2014; 4:303-14. [PMID: 25354695 PMCID: PMC4329013 DOI: 10.1002/cam4.349] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 08/21/2014] [Indexed: 12/18/2022] Open
Abstract
Hypoxia-inducible factor-1 (HIF-1) governs cellular adaption to the hypoxic microenvironment and is associated with a proliferative, metastatic, and treatment-resistant tumor phenotype. HIF-1 levels and transcriptional activity are regulated by proline and asparagine hydroxylases, which require ascorbate as cofactor. Ascorbate supplementation reduced HIF-1 activation in vitro, but only limited data are available in relevant animal models. There is no information of the effect of physiological levels of ascorbate on HIF activity and tumor growth, which was measured in this study. C57BL/6 Gulo−/− mice (a model of the human ascorbate dependency condition) were supplemented with 3300 mg/L, 330 mg/L, or 33 mg/L of ascorbate in their drinking water before and during subcutaneous tumor growth of B16-F10 melanoma or Lewis lung carcinoma (LL/2). Ascorbate levels in tumors increased significantly with elevated ascorbate intake and restoration of wild-type ascorbate levels led to a reduction in growth of B16-F10 (log phase P < 0.001) and LL/2 tumors (lag growth P < 0.001, log phase P < 0.05). Levels of HIF-1α protein in tumors decreased as dietary ascorbate supplementation increased for both tumor models (P < 0.001). Similarly, tumor ascorbate was inversely correlated with levels of the HIF-1 target proteins CA-IX, GLUT-1, and VEGF in both B16-F10 and LL/2 tumors (P < 0.05). The extent of necrosis was similar between ascorbate groups but varied between models (30% for B16-F10 and 21% for LL/2), indicating that ascorbate did not affect tumor hypoxia. Our data support the hypothesis that restoration of optimal intracellular ascorbate levels reduces tumor growth via moderation of HIF-1 pathway activity.
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Affiliation(s)
- Elizabeth J Campbell
- Mackenzie Cancer Research Group, Department of Pathology, University of Otago, Christchurch, New Zealand
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Carr AC, Vissers MCM, Cook JS. The effect of intravenous vitamin C on cancer- and chemotherapy-related fatigue and quality of life. Front Oncol 2014; 4:283. [PMID: 25360419 PMCID: PMC4199254 DOI: 10.3389/fonc.2014.00283] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 09/29/2014] [Indexed: 12/30/2022] Open
Abstract
Cancer patients commonly experience a number of symptoms of disease progression and the side-effects of radiation therapy and adjuvant chemotherapy, which adversely impact on their quality of life (QOL). Fatigue is one of the most common and debilitating symptom reported by cancer patients and can affect QOL more than pain. Several recent studies have indicated that intravenous (IV) vitamin C alleviates a number of cancer- and chemotherapy-related symptoms, such as fatigue, insomnia, loss of appetite, nausea, and pain. Improvements in physical, role, cognitive, emotional, and social functioning, as well as an improvement in overall health, were also observed. In this mini review, we briefly cover the methods commonly used to assess health-related QOL in cancer patients, and describe the few recent studies examining the effects of IV vitamin C on cancer- and chemotherapy-related QOL. We discuss potential mechanisms that might explain an improvement in QOL and also considerations for future studies.
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Affiliation(s)
- Anitra C Carr
- Department of Pathology, Centre for Free Radical Research, University of Otago , Christchurch , New Zealand
| | - Margreet C M Vissers
- Department of Pathology, Centre for Free Radical Research, University of Otago , Christchurch , New Zealand
| | - John S Cook
- New Brighton Health Care , Christchurch , New Zealand
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Carr AC, Vissers MCM, Cook J. Parenteral vitamin C for palliative care of terminal cancer patients. N Z Med J 2014; 127:84-86. [PMID: 24997468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- Anitra C Carr
- Department of Pathology, University of Otago, Christchurch, New Zealand
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Kuiper C, Dachs GU, Currie MJ, Vissers MCM. Intracellular ascorbate enhances hypoxia-inducible factor (HIF)-hydroxylase activity and preferentially suppresses the HIF-1 transcriptional response. Free Radic Biol Med 2014; 69:308-17. [PMID: 24495550 DOI: 10.1016/j.freeradbiomed.2014.01.033] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 01/22/2014] [Accepted: 01/25/2014] [Indexed: 12/17/2022]
Abstract
Hypoxia-inducible factor (HIF)-1 drives the transcription of hundreds of genes to support cell survival under conditions of microenvironmental and metabolic stress. HIF-1 is downregulated by iron-containing 2-oxoglutarate-dependent enzymes that require ascorbate as a cofactor. The HIF hydroxylases control both protein stability and the formation of an active transcription complex and, consequently, ascorbate could affect HIF-1α stabilization and/or gene expression, but the relative effect of ascorbate on these separate processes has not been well characterized. In this study we examined the effects of known intracellular ascorbate concentrations on both processes in response to various means of hydroxylase inhibition, including CoCl2, NiCl2, desferrioxamine, dimethyloxalylglycine, and hypoxia. Ascorbate inhibited HIF-1 activity most dramatically with all mechanisms of iron competition. In addition, HIF-1-dependent gene expression was effectively prevented by ascorbate and was inhibited even under conditions that allowed HIF-1α protein stabilization. This suggests that (1) ascorbate acts primarily to stabilize and reduce the iron atom in the hydroxylase active site and (2) the asparagine hydroxylase controlling HIF-1 transcriptional activity is particularly susceptible to fluctuations in intracellular ascorbate. These findings suggest that ascorbate plays a significant role in supporting HIF-hydroxylase function and that it could thereby modulate the cell survival response.
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Affiliation(s)
- Caroline Kuiper
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago at Christchurch, Christchurch 8140, New Zealand.
| | - Gabi U Dachs
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago at Christchurch, Christchurch 8140, New Zealand
| | - Margaret J Currie
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago at Christchurch, Christchurch 8140, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago at Christchurch, Christchurch 8140, New Zealand
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Dachs GU, Munn DG, Carr AC, Vissers MCM, Robinson BA. Consumption of vitamin C is below recommended daily intake in many cancer patients and healthy volunteers in Christchurch. N Z Med J 2014; 127:73-76. [PMID: 24670594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- Gabi U Dachs
- Mackenzie Cancer Research Group, Department of Pathology, University of Otago, Christchurch, New Zealand.
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Kuiper C, Dachs GU, Munn D, Currie MJ, Robinson BA, Pearson JF, Vissers MCM. Increased Tumor Ascorbate is Associated with Extended Disease-Free Survival and Decreased Hypoxia-Inducible Factor-1 Activation in Human Colorectal Cancer. Front Oncol 2014; 4:10. [PMID: 24551593 PMCID: PMC3912592 DOI: 10.3389/fonc.2014.00010] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/17/2014] [Indexed: 12/13/2022] Open
Abstract
Ascorbate is a co-factor for the hydroxylases that regulate the transcription factor hypoxia-inducible factor (HIF)-1, which provides cancer cells with a metabolic and survival advantage in the hypoxic environment of solid tumors. However, whether ascorbate affects tumor development is a highly debated issue. We aimed to determine whether tumor ascorbate was associated with HIF-1 activation and patient disease-free survival. In this study, we undertook a retrospective observational analysis of tissue-banked tumor and paired normal tissue from 49 colorectal cancer patients, measuring ascorbate levels, HIF-1α and its downstream gene products BNIP3, and vascular endothelial cell growth factor (VEGF). Patient survival was monitored for the first 6 years after surgery. We found that ascorbate levels were lower in tumor tissue compared to normal tissue (p < 0.001) but overall levels varied considerably. HIF-1α, VEGF, and BNIP3 were elevated in tumor samples (p < 0.01). There was an inverse relationship between tumor ascorbate content and HIF-1 pathway activation (p = 0.002) and tumor size (p = 0.018). Higher tumor ascorbate content was associated with significantly improved disease-free survival in the first 6 years after surgery (p = 0.006), with 141–1,094 additional disease-free days. This was independent of tumor grade and stage. Survival advantage was associated with the amount of ascorbate in the tumor, but not with the amount in adjacent normal tissue. Our results demonstrate that higher tumor ascorbate content is associated with decreased HIF-1 activation, most likely due to the co-factor activity of ascorbate for the regulatory HIF hydroxylases. Our findings support the need for future studies to determine whether raising tumor ascorbate is possible with clinical intervention and whether this results in modification of hydroxylase-dependent pathways in the tumor.
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Affiliation(s)
- Caroline Kuiper
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand
| | - Gabi U Dachs
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand
| | - Delwyn Munn
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand
| | - Margaret J Currie
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand
| | - Bridget A Robinson
- Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand ; Canterbury Regional Cancer and Blood Service, Canterbury District Health Board, Christchurch Hospital , Christchurch , New Zealand
| | - John F Pearson
- Biostatistics and Computational Biology Unit, Department of Public Health and General Practice, University of Otago Christchurch , Christchurch , New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch , Christchurch , New Zealand
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Carr AC, Vissers MCM, Cook J. Relief from cancer chemotherapy side effects with pharmacologic vitamin C. N Z Med J 2014; 127:66-70. [PMID: 24481389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Fatigue is a common, often debilitating, side effect of cancer chemotherapy. Pharmacologic vitamin C has been used as an alternative treatment for the disease itself but its effects on fatigue have not often been documented. Here we report on the case of a woman with recurrent breast cancer, undergoing weekly chemotherapy, with lethargy as a major symptom. Vitamin C (50 g/session) was administered twice weekly and quality of life and multidimensional fatigue symptomology questionnaires were undertaken. Dramatic decreases in fatigue and insomnia were observed, as well as increased cognitive functioning. There were no adverse side effects of i.v. vitamin C.
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Affiliation(s)
- Anitra C Carr
- Department of Pathology, University of Otago, Christchurch, PO Box 4345, Christchurch 8140, New Zealand.
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Carr AC, Bozonet SM, Vissers MCM. A randomised cross-over pharmacokinetic bioavailability study of synthetic versus kiwifruit-derived vitamin C. Nutrients 2013; 5:4451-61. [PMID: 24284610 PMCID: PMC3847741 DOI: 10.3390/nu5114451] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 10/08/2013] [Accepted: 10/24/2013] [Indexed: 11/17/2022] Open
Abstract
Kiwifruit are a rich source of vitamin C and also contain numerous phytochemicals, such as flavonoids, which may influence the bioavailability of kiwifruit-derived vitamin C. The aim of this study was to compare the relative bioavailability of synthetic versus kiwifruit-derived vitamin C using a randomised cross-over pharmacokinetic study design. Nine non-smoking males (aged 18–35 years) received either a chewable tablet (200 mg vitamin C) or the equivalent dose from gold kiwifruit (Actinidia chinensis var. Sungold). Fasting blood and urine were collected half hourly to hourly over the eight hours following intervention. The ascorbate content of the plasma and urine was determined using HPLC with electrochemical detection. Plasma ascorbate levels increased from 0.5 h after the intervention (P = 0.008). No significant differences in the plasma time-concentration curves were observed between the two interventions (P = 0.645). An estimate of the total increase in plasma ascorbate indicated complete uptake of the ingested vitamin C tablet and kiwifruit-derived vitamin C. There was an increase in urinary ascorbate excretion, relative to urinary creatinine, from two hours post intervention (P < 0.001). There was also a significant difference between the two interventions, with enhanced ascorbate excretion observed in the kiwifruit group (P = 0.016). Urinary excretion was calculated as ~40% and ~50% of the ingested dose from the vitamin C tablet and kiwifruit arms, respectively. Overall, our pharmacokinetic study has shown comparable relative bioavailability of kiwifruit-derived vitamin C and synthetic vitamin C.
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Affiliation(s)
- Anitra C Carr
- Centre for Free Radical Research, Department of Pathology & Biomedical Science, University of Otago, Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand.
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Carr AC, Pullar JM, Vissers MCM. Beating the blues--the association between fruit and vegetable intake and improved mood. N Z Med J 2013; 126:131-132. [PMID: 24162641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Affiliation(s)
| | - Juliet M Pullar
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand
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Pullar JM, Carr AC, Vissers MCM. Vitamin C supplementation and kidney stone risk. N Z Med J 2013; 126:133-134. [PMID: 24162642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Affiliation(s)
| | - Anitra C Carr
- Centre for Free Radical Research, Department of Pathology, University of Otago, Christchurch, New Zealand
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Carr AC, Bozonet SM, Pullar JM, Simcock JW, Vissers MCM. A randomized steady-state bioavailability study of synthetic versus natural (kiwifruit-derived) vitamin C. Nutrients 2013; 5:3684-95. [PMID: 24067392 PMCID: PMC3798928 DOI: 10.3390/nu5093684] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 08/15/2013] [Accepted: 08/26/2013] [Indexed: 01/07/2023] Open
Abstract
Whether vitamin C from wholefoods has equivalent bioavailability to a purified supplement remains unclear. We have previously showed that kiwifruit provided significantly higher serum and tissue ascorbate levels than synthetic vitamin C in a genetically vitamin C-deficient mouse model, suggesting a synergistic activity of the whole fruit. To determine if these results are translatable to humans, we carried out a randomized human study comparing the bioavailability of vitamin C from kiwifruit with that of a vitamin C tablet of equivalent dosage. Thirty-six young non-smoking adult males were randomized to receive either half a gold kiwifruit (Actinidia Chinensis var. Hort 16A) per day or a comparable vitamin C dose (50 mg) in a chewable tablet for six weeks. Ascorbate was monitored weekly in fasting venous blood and in urine, semen, leukocytes, and skeletal muscle (vastus lateralis) pre- and post-intervention. Dietary intake of vitamin C was monitored using seven day food and beverage records. Participant ascorbate levels increased in plasma (P < 0.001), urine (P < 0.05), mononuclear cells (P < 0.01), neutrophils (P < 0.01) and muscle tissue (P < 0.001) post intervention. There were no significant differences in vitamin C bioavailability between the two intervention groups in any of the fluid, cell or tissue samples tested. Overall, our study showed comparable bioavailability of synthetic and kiwifruit-derived vitamin C.
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Affiliation(s)
- Anitra C. Carr
- Centre for Free Radical Research, Department of Pathology & Biomedical Science, University of Otago, Christchurch, PO Box 4345, Christchurch 8140, New Zealand; E-Mails: (S.M.B.); (J.M.P.); margreet.vissers@otag (M.C.M.V.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +64-3-378-6498; Fax: +64-3-378-6540
| | - Stephanie M. Bozonet
- Centre for Free Radical Research, Department of Pathology & Biomedical Science, University of Otago, Christchurch, PO Box 4345, Christchurch 8140, New Zealand; E-Mails: (S.M.B.); (J.M.P.); margreet.vissers@otag (M.C.M.V.)
| | - Juliet M. Pullar
- Centre for Free Radical Research, Department of Pathology & Biomedical Science, University of Otago, Christchurch, PO Box 4345, Christchurch 8140, New Zealand; E-Mails: (S.M.B.); (J.M.P.); margreet.vissers@otag (M.C.M.V.)
| | - Jeremy W. Simcock
- Department of Plastic and Reconstructive Surgery, University of Otago, Christchurch, PO Box 4345, Christchurch 8140, New Zealand; E-Mail:
| | - Margreet C. M. Vissers
- Centre for Free Radical Research, Department of Pathology & Biomedical Science, University of Otago, Christchurch, PO Box 4345, Christchurch 8140, New Zealand; E-Mails: (S.M.B.); (J.M.P.); margreet.vissers@otag (M.C.M.V.)
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Carr AC, Vissers MCM, Lewis J, Elder P. Multiple nutrient insufficiencies--hypovitaminosis D and C in young adult New Zealand males. N Z Med J 2012; 125:119-120. [PMID: 23242409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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Parker A, Cuddihy SL, Son TG, Vissers MCM, Winterbourn CC. Roles of superoxide and myeloperoxidase in ascorbate oxidation in stimulated neutrophils and H2O2-treated HL60 cells. Free Radic Biol Med 2011; 51:1399-405. [PMID: 21791243 DOI: 10.1016/j.freeradbiomed.2011.06.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 06/22/2011] [Accepted: 06/24/2011] [Indexed: 11/29/2022]
Abstract
Ascorbate is present at high concentrations in neutrophils and becomes oxidized when the cells are stimulated. We have investigated the mechanism of oxidation by studying cultured HL60 cells and isolated neutrophils. Addition of H(2)O(2) to ascorbate-loaded HL60 cells resulted in substantial oxidation of intracellular ascorbate. Oxidation was myeloperoxidase-dependent, but not attributable to hypochlorous acid, and can be explained by myeloperoxidase (MPO) exhibiting direct ascorbate peroxidase activity. When neutrophils were stimulated with phorbol myristate acetate, about 40% of their intracellular ascorbate was oxidized over 20 min. Ascorbate loss required NADPH oxidase activity but in contrast to the HL60 cells did not involve myeloperoxidase. It did not occur when exogenous H(2)O(2) was added, was not inhibited by myeloperoxidase inhibitors, and was the same for normal and myeloperoxidase-deficient cells. Neutrophil ascorbate loss was enhanced when endogenous superoxide dismutase was inhibited by cyanide or diethyldithiocarbamate and appears to be due to oxidation by superoxide. We propose that in HL60 cells, MPO-dependent ascorbate oxidation occurs because cellular ascorbate can access newly synthesized MPO before it becomes packaged in granules: a mechanism not possible in neutrophils. In neutrophils, we estimate that ascorbate is capable of competing with superoxide dismutase for a small fraction of the superoxide they generate and propose that the superoxide responsible is likely to come from previously identified sites of intracellular NADPH oxidase activity. We speculate that ascorbate might protect the neutrophil against intracellular effects of superoxide generated at these sites.
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Affiliation(s)
- Amber Parker
- Department of Pathology, University of Otago Christchurch, Christchurch, New Zealand
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50
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Vissers MCM, Bozonet SM, Pearson JF, Braithwaite LJ. Dietary ascorbate intake affects steady state tissue concentrations in vitamin C-deficient mice: tissue deficiency after suboptimal intake and superior bioavailability from a food source (kiwifruit). Am J Clin Nutr 2011; 93:292-301. [PMID: 21123463 DOI: 10.3945/ajcn.110.004853] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Humans acquire vitamin C (ascorbate) from their diet, and optimal tissue concentrations are required to maintain its enzyme cofactor and antioxidant activities. How dietary intake affects tissue concentrations is difficult to monitor and has generally been based on the measurement of plasma concentrations. OBJECTIVE We aimed to determine the effect of various ascorbate intakes on tissue concentrations in the Gulo mouse model of vitamin C deficiency and to compare the effectiveness of delivery when ascorbate was added to the drinking water or obtained through a fruit source (kiwifruit). DESIGN Gulo(-/-) mice were fed various amounts of ascorbate for 1 mo, either in their drinking water or as a kiwifruit gel. Tissue vitamin C content was measured and compared with concentrations in wild-type mice. RESULTS Ascorbate concentrations in serum, liver, kidney, heart, and white blood cells were extremely labile and were well below concentrations observed in the wild-type mice when serum concentrations were below saturation. All tissues except for brain were rapidly depleted when intake was stopped. Consumption of a preparation of fresh kiwifruit (either green or gold varieties) resulted in up to 5 times more effective delivery to tissues than when ascorbate was administered via the drinking water. CONCLUSIONS Subsaturation concentrations of plasma ascorbate resulted in severe deficiency in many tissues, and saturating amounts were required to achieve tissue concentrations similar to those found in wild-type animals. It is possible that the bioavailability of ascorbate is superior from some foods, such as kiwifruit. These results have important implications for human nutrition.
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