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A Covarrubias-Pinto, A I Acuña, G Boncompain, E Pápic, P V Burgos, F Perez, M A Castro
Ascorbic acid (Asc) is an antioxidant molecule essential for physiological functions. The concentration of extracellular Asc increases during synaptic transmission and renal reabsorption. These phenomena induce an increase of the Sodium-dependent-Vitamin-C-transporter 2 (SVCT2) at plasma membrane (PM) localization, as we previously demonstrated in neuronal and non-neuronal cells. Hence, the aim of this study was to evaluate intracellular SVCT2 trafficking kinetics in response to Asc. We observed two peaks of SVCT2 localization and function at the PM (at 5-10min, "acute response", and 30-60min, "post-acute response") when cells were incubated with Asc...
March 12, 2018: Free Radical Biology & Medicine
Karina Oyarce, Mauricio Campos-Mora, Tania Gajardo-Carrasco, Karina Pino-Lagos
Regulatory T cells (Tregs) are critical players of immunological tolerance due to their ability to suppress effector T cell function thereby preventing transplant rejection and autoimmune diseases. During allograft transplantation, increases of both Treg expansion and generation, as well as their stable function, are needed to ensure allograft acceptance; thus, efforts have been made to discover new molecules that enhance Treg-mediated tolerance and to uncover their mechanisms. Recently, vitamin C (VitC), known to regulate T cell maturation and dendritic cell-mediated T cell polarization, has gained attention as a relevant epigenetic remodeler able to enhance and stabilize the expression of the Treg master regulator gene Foxp3, positively affecting the generation of induced Tregs (iTregs)...
2018: Frontiers in Immunology
Thaísa Godinho da Encarnação, Camila Cabral Portugal, Caio Eduardo Nogueira, Felipe Nascimento Santiago, Renato Socodato, Roberto Paes-de-Carvalho
Ascorbate, the reduced form of vitamin C, is highly concentrated in the central nervous system (CNS), including the retina, where it plays important physiological functions. In the CNS, the plasma membrane transporter sodium vitamin C co-transporter 2 (SVCT2) is responsible for ascorbate transport in neurons. The neurotransmitter dopamine (DA), acting through D1 - and D2 -like receptor subfamilies and classically coupled to adenylyl cyclase, is known to modulate synaptic transmission in the retina. Here, we reveal that DA controls the release of ascorbate from retinal neurons...
February 23, 2018: Molecular Neurobiology
P Marcos, J González-Fuentes, L Castro-Vázquez, M V Lozano, M J Santander-Ortega, V Rodríguez-Robledo, N Villaseca-González, M M Arroyo-Jiménez
Its high metabolic rate and high polyunsaturated fatty acid content make the brain very sensitive to oxidative damage. In the brain, neuronal metabolism occurs at a very high rate and generates considerable amounts of reactive oxygen species and free radicals, which accumulate inside neurons, leading to altered cellular homeostasis and integrity and eventually irreversible damage and cell death. A misbalance in redox metabolism and the subsequent neurodegeneration increase throughout the course of normal aging, leading to several age-related changes in learning and memory as well as motor functions...
January 8, 2018: Journal of Anatomy
Camila C Portugal, Renato Socodato, João B Relvas
No abstract text is available yet for this article.
November 21, 2017: Oncotarget
Mohammed M Aldajani, Clemens N Vanicek, Norah Alhazzaa, Taras Lysyy, Raghav Agarwal, John P Geibel
BACKGROUND/AIM: Colorectal cancer is still considered a leading cause of death in the United States and worldwide. One potential way to improve survival besides detection is to look to new therapeutic agents that can be taken prophylactically to reduce the risk of tumor formation. For cancer cells to grow and invade, a higher (more alkaline) intracellular pH must occur. We chose to examine a specific nutraceutical agent, which is Vitamin C. The acute effect of Vitamin C exposure on normal colonic crypts has been studied, providing some insight into how Vitamin C achieve its effect...
November 13, 2017: Cellular Physiology and Biochemistry
Katterine Salazar, Fernando Martínez, Margarita Pérez-Martín, Manuel Cifuentes, Laura Trigueros, Luciano Ferrada, Francisca Espinoza, Natalia Saldivia, Romina Bertinat, Katherine Forman, María José Oviedo, Antonio J López-Gambero, Christian Bonansco, Ernesto R Bongarzone, Francisco Nualart
Ascorbic acid (AA), the reduced form of vitamin C, acts as a neuroprotector by eliminating free radicals in the brain. Sodium/vitamin C co-transporter isoform 2 (SVCT2) mediates uptake of AA by neurons. It has been reported that SVCT2 mRNA is induced in astrocytes under ischemic damage, suggesting that its expression is enhanced in pathological conditions. However, it remains to be established if SVCT expression is altered in the presence of reactive astrogliosis generated by different brain pathologies. In the present work, we demonstrate that SVCT2 expression is increased in astrocytes present at sites of neuroinflammation induced by intracerebroventricular injection of a GFP-adenovirus or the microbial enzyme, neuraminidase...
September 23, 2017: Molecular Neurobiology
Kavita R Gajbhiye, Virendra Gajbhiye, Imtiaz A Siddiqui, Srikanth Pilla, Vandana Soni
The aim of this work was to enhance the transportation of the galantamine to the brain via ascorbic acid grafted PLGA-b-PEG nanoparticles (NPs) using SVCT2 transporters of choroid plexus. PLGA-b-PEG copolymer was synthesized and characterized by (1)H NMR, gel permeation chromatography, and differential scanning calorimetry. PLGA-b-PEG-NH2 and PLGA-b-mPEG NPs were prepared by nanoprecipitation method. PLGA-b-PEG NPs with desirable size, polydispersity, and drug loading were used for the conjugation with ascorbic acid (PLGA-b-PEG-Asc) to facilitate SVCT2 mediated transportation of the same into the brain...
September 11, 2017: Scientific Reports
Shilpy Dixit, Joshua P Fessel, Fiona E Harrison
Mitochondrial dysfunction is elevated in very early stages of Alzheimer's disease and exacerbates oxidative stress, which contributes to disease pathology. Mitochondria were isolated from 4-month-old wild-type mice, transgenic mice carrying the APPSWE and PSEN1dE9 mutations, mice with decreased brain and mitochondrial ascorbate (vitamin C) via heterozygous knockout of the sodium dependent vitamin C transporter (SVCT2(+/-)) and transgenic APP/PSEN1 mice with heterozygous SVCT2 expression. Mitochondrial isolates from SVCT2(+/-) mice were observed to consume less oxygen using high-resolution respirometry, and also exhibited decreased mitochondrial membrane potential compared to wild type isolates...
November 2017: Free Radical Biology & Medicine
Orazio Cantoni, Andrea Guidarelli, Mara Fiorani
SIGNIFICANCE: The mitochondrial fraction of l-ascorbic acid (AA) is of critical importance for the regulation of the redox status of these organelles and for cell survival. Recent Advances: Most cell types take up AA by the high-affinity sodium-dependent vitamin C transporter 2 (SVCT2) sensitive to inhibition by dehydroascorbic acid (DHA). DHA can also be taken up by glucose transporters (GLUTs) and then reduced back to AA. DHA concentrations, normally very low in biological fluids, may only become significant next to superoxide-releasing cells...
August 9, 2017: Antioxidants & Redox Signaling
Dominik Röhr, Hartmut Halfter, Jörg B Schulz, Peter Young, Burkhard Gess
Peripheral nerve myelination involves rapid production of tightly bound lipid layers requiring cholesterol biosynthesis and myelin protein expression, but also a collagen-containing extracellular matrix providing mechanical stability. In previous studies, we showed a function of ascorbic acid in peripheral nerve myelination and extracellular matrix formation in adult mice. Here, we sought the mechanism of action of ascorbic acid in peripheral nerve myelination using different paradigms of myelination in vivo and in vitro...
April 29, 2017: Glia
Changzheng Wang, Hongwei Lv, Wen Yang, Ting Li, Tian Fang, Guishuai Lv, Qin Han, Liwei Dong, Tianyi Jiang, Beige Jiang, Guangshun Yang, Hongyang Wang
Cholangiocarcinoma (CC) is a devastating malignancy with late diagnosis and poor response to conventional chemotherapy. Recent studies have revealed anti-cancer effect of vitamin C (l-ascorbic acid, ascorbate) in several types of cancer. However, the effect of l-ascorbic acid (AA) in CC remains elusive. Herein, we demonstrated that AA induced cytotoxicity in CC cells by generating intracellular reactive oxygen species (ROS), and subsequently DNA damage, ATP depletion, mTOR pathway inhibition. Moreover, AA worked synergistically with chemotherapeutic agent cisplatin to impair CC cells growth both in vitro and in vivo...
July 10, 2017: Cancer Letters
Camila C Portugal, Renato Socodato, Teresa Canedo, Cátia M Silva, Tânia Martins, Vivian S M Coreixas, Erick C Loiola, Burkhard Gess, Dominik Röhr, Ana R Santiago, Peter Young, Richard D Minshall, Roberto Paes-de-Carvalho, António F Ambrósio, João B Relvas
Vitamin C is essential for the development and function of the central nervous system (CNS). The plasma membrane sodium-vitamin C cotransporter 2 (SVCT2) is the primary mediator of vitamin C uptake in neurons. SVCT2 specifically transports ascorbate, the reduced form of vitamin C, which acts as a reducing agent. We demonstrated that ascorbate uptake through SVCT2 was critical for the homeostasis of microglia, the resident myeloid cells of the CNS that are essential for proper functioning of the nervous tissue...
March 28, 2017: Science Signaling
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
Fryad Rahman, Benoit Bordignon, Raphael Culerrier, Franck Peiretti, Salvatore Spicuglia, Malek Djabali, Jean François Landrier, Michel Fontes
SCOPE: Here we tested the hypothesis that ascorbic acid (AA) is a signaling 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...
May 2017: 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 2017: 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
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