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Karina Oyarce, Carmen Silva-Alvarez, Luciano Ferrada, Fernando Martínez, Katterine Salazar, Francisco Nualart
Ascorbic acid (AA) is a known antioxidant that participates in a wide range of processes, including stem cell differentiation. It enters the cell through the sodium-ascorbate co-transporter SVCT2, which is mainly expressed by neurons in the adult brain. Here, we have characterized SVCT2 expression in the postnatal cerebellum in situ, a model used for studying neurogenesis, and have identified its expression in granular precursor cells and mature neurons. We have also detected SVCT2 expression in the cerebellar cell line C17...
January 17, 2017: Molecular Neurobiology
Adam P Fischer, Sarah L Miles
INTRODUCTION: Accumulation of hypoxia inducible factor-1 alpha (HIF-1α) in malignant tissue is known to contribute to oncogenic progression and is inversely associated with patient survival. Ascorbic acid (AA) depletion in malignant tissue may contribute to aberrant normoxic activity of HIF-1α. While AA supplementation has been shown to attenuate HIF-1α function in malignant melanoma, the use of dehydroascorbic acid (DHA) as a therapeutic means to increase intracellular AA and modulate HIF-1α function is yet to be evaluated...
February 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
F Rahman, B Bordignon, R Culerrier, F Peiretti, S Spicuglia, M Djabali, J F Landrier, M Fontes
SCOPE: Here we tested the hypothesis that ascorbic acid (AA) is a signalling molecule acting on stem cells via the differentiation of mesoderm derivatives, including myocytes, osteocytes and adipocytes. MATERIAL AND METHODS: Investigations used a murine embryonic stem cell line CGR8 able to differentiate into different cell types and treated or not with ascorbic acid. Differentiation was tracked mainly through cellular anatomy (including presence of beating cardiomyocytes) and expression of specific markers...
December 13, 2016: Molecular Nutrition & Food Research
C Silva-Álvarez, K Salazar, P Cisternas, F Martínez, S Liour, N Jara, R Bertinat, F Nualart
During brain development, radial glial (RG) cells and the different progenitor subtypes are characterized by their bipolar morphology that includes an ovoid cell body and one or two radial processes that span across the developing cerebral wall. Different cells transport the reduced form of vitamin C, ascorbic acid (AA), using sodium-dependent ascorbic acid cotransporters (SVCT1 or SVCT2). SVCT2 is mainly expressed in the nervous system (CNS); however, its localization in the central nervous system during embryonic development along with the mechanism by which RG take up vitamin C and its intracellular effects is unknown...
September 5, 2016: Molecular Neurobiology
Jun-Man Hong, Jin-Hee Kim, Jae Seung Kang, Wang Jae Lee, Young-Il Hwang
Vitamin C is an essential micronutrient that affects immune responses. T cells are one of the main players in acquired immunity and have been reported to be influenced by in vivo vitamin C supplementation. Yet, the way by which T cells uptake vitamin C and what direct effects vitamin C exerts on the cells are not known. To elucidate, we isolated human peripheral blood T cells and analyzed the expression of sodium-dependent vitamin C transporters (SVCT). T cells were activated in vitro in the absence or presence of vitamin C, before or after activation...
June 2016: Anatomy & Cell Biology
Nan Ma, Carla Siegfried, Miyuki Kubota, Jie Huang, Ying Liu, Margaret Liu, Belinda Dana, Andrew Huang, David Beebe, Hong Yan, Ying-Bo Shui
PURPOSE: Ascorbic acid (AsA) is an important antioxidant in the eye. Ascorbic acid is usually transported by sodium-dependent AsA transporters (SVCTs), and dehydroascorbic acid (DHA) by glucose transporters (GLUTs). This study investigates these AsA-related transporters in human compared with mouse eyes. METHODS: Five pairs of human donor eyes and 15 pairs of mouse eyes were collected. Immunofluorescence and in situ hybridization were performed to detect SVCTs and GLUTs expression in the ciliary epithelium, retina, and lens epithelial cells (LECs)...
June 1, 2016: Investigative Ophthalmology & Visual Science
Rui Li, Le Shen, Xuerong Yu, Chao Ma, Yuguang Huang
AIMS: Gabapentin (Gap) relieves neuropathic pain, but it has several adverse effects as well. We aimed to investigate whether vitamin C (VitC) supplementation would reduce the effective dose of Gap for analgesia in rats with chronic constriction injury (CCI). MAIN METHODS: Rats were randomly assigned to Sham, CCI, VitC, Gap, and VitC+Gap treatment groups. CCI, involving the left sciatic nerve, was induced in all animals except the Sham group. VitC (500mg/kg (body weight)), Gap (10, 30, or 100mg/kg), or VitC (500mg/kg)+Gap (10, 30, or 100mg/kg) were injected intraperitoneally twice daily for a week from 7days after sham or CCI surgery...
July 15, 2016: Life Sciences
Hua Tian, Xiaoxia Ye, Xiaojie Hou, Xiaowei Yang, Jingyu Yang, Chunfu Wu
Sodium vitamin C transporter 2 (SVCT2) plays a key role in transporting ascorbic acid (AA), an important intracellular antioxidant, into neurons. It is well known that ethanol (EtOH) abuse causes significant neurodegeneration, as well as endogenous AA release in certain encephalic regions. Here, we identified that SVCT2 forms part of a self-defense mechanism that protects against oxidative stress in binge drinking rats, and SVCT2 levels are correlated with antioxidants and neuronal injury. Four days of binge drinking led to massive neuron degeneration in prefrontal cortex (PFC), accompanied by increased levels of 4-hydroxynonenal (4-HNE)-adducted proteins and SVCT2 expression, as well as dramatic changes in AA levels in rat brain...
July 2016: Free Radical Biology & Medicine
Soo-A Jung, Dae-Hee Lee, Jai-Hee Moon, Seung-Woo Hong, Jae-Sik Shin, Ih Yeon Hwang, Yu Jin Shin, Jeong Hee Kim, Eun-Yeung Gong, Seung-Mi Kim, Eun Young Lee, Seul Lee, Jeong Eun Kim, Kyu-Pyo Kim, Yong Sang Hong, Jung Shin Lee, Dong-Hoon Jin, TaeWon Kim, Wang Jae Lee
Colon cancer patients with mutant KRAS are resistant to cetuximab, an antibody directed against the epidermal growth factor receptor, which is an effective clinical therapy for patients with wild-type KRAS. Numerous combinatorial therapies have been tested to overcome the resistance to cetuximab. However, no combinations have been found that can be used as effective therapeutic strategies. In this study, we demonstrate that L-ascorbic acid partners with cetuximab to induce killing effects, which are influenced by sodium-dependent vitamin C transporter 2 (SVCT-2) in human colon cancer cells with a mutant KRAS...
June 2016: Free Radical Biology & Medicine
Shaun A Mason, Paul A Della Gatta, Rod J Snow, Aaron P Russell, Glenn D Wadley
AIM/HYPOTHESIS: Skeletal muscle insulin resistance and oxidative stress are characteristic metabolic disturbances in people with type 2 diabetes. Studies in insulin resistant rodents show an improvement in skeletal muscle insulin sensitivity and oxidative stress following antioxidant supplementation. We therefore investigated the potential ameliorative effects of antioxidant ascorbic acid (AA) supplementation on skeletal muscle insulin sensitivity and oxidative stress in people with type 2 diabetes...
April 2016: Free Radical Biology & Medicine
Katterine Salazar, Milka Martínez, Viviana Ulloa, Romina Bertinat, Fernando Martínez, Nery Jara, Francisca Espinoza, Ernesto R Bongarzone, Francisco Nualart
Expression of the sodium and ascorbic acid (AA) cotransporter SVCT2 is induced during the period of cellular arborization and synaptic maturation of early postnatal (P1-P5) rat cerebral neurons. The physiological importance of the transporter for neurons is evidenced by the lethality and delayed neuronal differentiation detected in mice with ablation of SVCT2. The mechanism(s) involved in these defects and the role of SVCT2 in neuronal branching have not been determined yet. To address this, we used lentiviral expression vectors to increase the levels of SVCT2 in N2a cells and analyzed the effects on neurite formation...
December 2016: Molecular Neurobiology
Andrea García-Krauss, Luciano Ferrada, Allisson Astuya, Katterine Salazar, Pedro Cisternas, Fernando Martínez, Eder Ramírez, Francisco Nualart
Ascorbic acid (AA), the reduced form of vitamin C, is incorporated into neurons via the sodium ascorbate co-transporter SVCT2. However, this transporter is not expressed in astrocytes, which take up the oxidized form of vitamin C, dehydroascorbic acid (DHA), via the facilitative hexose transporter GLUT1. Therefore, neuron and astrocyte interactions are thought to mediate vitamin C recycling in the nervous system. Although astrocytes are essential for the antioxidant defense of neurons under oxidative stress, a condition in which a large amount of ROS is generated that may favor the extracellular oxidation of AA and the subsequent neuronal uptake of DHA via GLUT3, potentially increasing oxidative stress in neurons...
October 26, 2015: Molecular Neurobiology
Marquicia R Pierce, Amita Raj, Katherine M Betke, L Nora Zeidan, Heinrich J G Matthies, James M May
It has been shown that vitamin C (VC) is transported at synaptic boutons, but how this occurs has not been elucidated. This study investigates the role of the sodium-dependent vitamin C transporter-2 (SVCT2) in transporting VC at the cortical nerve terminal. Immunostaining of cultured mouse superior cervical ganglion cells showed the SVCT2 to be expressed in presynaptic boutons, colocalizing with the vesicular monoamine transporter-2 and the norepinephrine transporter. Immunoblotting of enriched cortical synaptosomes demonstrated that the SVCT2 was enriched in presynaptic fractions, confirming a predominantly presynaptic location...
December 2015: Journal of Neuroscience Research
James M May, Zhi-Chao Qu
Microvascular pericytes take up ascorbic acid on the ascorbate transporter SVCT2. Intracellular ascorbate then protects the cells against apoptosis induced by culture at diabetic glucose concentrations. To investigate whether pericytes might also provide ascorbate to the underlying endothelial cells, we studied ascorbate efflux from human pericytes. When loaded with ascorbate to intracellular concentrations of 0.8-1.0 mM, almost two-thirds of intracellular ascorbate effluxed from the cells over 2 H. This efflux was opposed by ascorbate re-uptake from the medium, since preventing re-uptake by destroying extracellular ascorbate with ascorbate oxidase increased ascorbate loss even further...
September 2015: BioFactors
Rajnikumar Sangani, Sudharsan Periyasamy-Thandavan, Rajneesh Pathania, Saif Ahmad, Ammar Kutiyanawalla, Ravindra Kolhe, Maryka H Bhattacharyya, Norman Chutkan, Monte Hunter, William D Hill, Mark Hamrick, Carlos Isales, Sadanand Fulzele
Vitamin C is an antioxidant that plays a vital role in various biological processes including bone formation. Previously, we reported that vitamin C is transported into bone marrow stromal cells (BMSCs) through the sodium dependent Vitamin C Transporter 2 (SVCT2) and this transporter plays an important role in osteogenic differentiation. Furthermore, this transporter is regulated by oxidative stress. To date, however, the exact role of vitamin C and its transporter (SVCT2) in ROS regulated autophagy and apoptosis in BMSCs is poorly understood...
September 2015: Stem Cell Research
Mara Fiorani, Catia Azzolini, Andrea Guidarelli, Liana Cerioni, Maddalena Scotti, Orazio Cantoni
Exposure of U937 cells to low concentrations of L-ascorbic acid (AA) is associated with a prompt cellular uptake and a further mitochondrial accumulation of the vitamin. Under the same conditions, dehydroascorbic acid (DHA) uptake was followed by rapid reduction and accumulation of identical intracellular levels of AA, however, in the absence of significant mitochondrial uptake. This event was instead observed after exposure to remarkably greater concentrations of DHA. Furthermore, experiments performed in isolated mitochondria revealed that DHA transport through hexose transporters and Na(+) -dependent transport of AA were very similar...
September 2015: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
Nirina Larsson, Gregory D Rankin, Elif M Bicer, Ester Roos-Engstrand, Jamshid Pourazar, Anders Blomberg, Ian S Mudway, Annelie F Behndig
OBJECTIVES: Vitamin C is an important low-molecular weight antioxidant at the air-lung interface. Despite its critical role as a sacrificial antioxidant, little is known about its transport into the respiratory tract lining fluid (RTLF), or the underlying airway epithelial cells. While several vitamin C transporters have been identified, such as sodium-ascorbate cotransporters (SVCT1/2) and glucose transporters (GLUTs), the latter transporting dehydroascorbate, knowledge of their protein distribution within the human lung is limited, in the case of GLUTs or unknown for SVCTs...
2015: BMJ Open
Mara Fiorani, Catia Azzolini, Liana Cerioni, Maddalena Scotti, Andrea Guidarelli, Caterina Ciacci, Orazio Cantoni
We recently reported that U937 cell mitochondria express a functional Na+-dependent ascorbic acid (AA) transporter recognised by anti-SVCT2 antibodies. The present study confirms and extends these observations by showing that this transporter is characterised by a Km and a pH-dependence comparable with that reported for the plasma membrane SVCT2. In isolated mitochondria, Na+ increased AA transport rate in a cooperative manner, revealed by a sigmoid curve and a Hill coefficient of 2, as also observed in intact Raw 264...
June 2015: Biochimica et Biophysica Acta
William H Parker, Zhi-Chao Qu, James M May
Intracellular vitamin C, or ascorbic acid, has been shown to prevent the apoptosis of cultured vascular pericytes under simulated diabetic conditions. We sought to determine the mechanism by which ascorbate is transported into pericytes prior to exerting this protective effect. Measuring intracellular ascorbate, we found that pericytes display a linear uptake over 30 min and an apparent transport Km of 21 μM, both of which are consistent with activity of the Sodium-dependent Vitamin C Transporter 2 (SVCT2)...
March 6, 2015: Biochemical and Biophysical Research Communications
Shilpy Dixit, Alexandra Bernardo, Jennifer Michelle Walker, John Andrew Kennard, Grace Youngeun Kim, Eric Sean Kessler, Fiona Edith Harrison
Subclinical vitamin C deficiency is widespread in many populations, but its role in both Alzheimer's disease and normal aging is understudied. In the present study, we decreased brain vitamin C in the APPSWE/PSEN1deltaE9 mouse model of Alzheimer's disease by crossing APP/PSEN1(+) bigenic mice with SVCT2(+/-) heterozygous knockout mice, which have lower numbers of the sodium-dependent vitamin C transporter required for neuronal vitamin C transport. SVCT2(+/-) mice performed less well on the rotarod task at both 5 and 12 months of age compared to littermates...
April 15, 2015: ACS Chemical Neuroscience
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