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Qi Z, Chen X, Zhu Y, Yue Q, Ji W. Electrochemical sensing of transient ascorbate fluctuation under hypoxic stress in live rat brain. Talanta 2025; 282:126996. [PMID: 39383720 DOI: 10.1016/j.talanta.2024.126996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2024] [Revised: 09/11/2024] [Accepted: 10/03/2024] [Indexed: 10/11/2024]
Abstract
Hypoxia, a common cause of programmed cell death or apoptosis, represents a neuropathological process. Although certain response proteins to hypoxic stress and their effects on cell status and fate have been identified, the real-time quantification of smaller neurochemicals to understand pathogenic mechanism in live rat brain during such stress remains unexplored. In this study, by employing a cutting-edge electrochemical tool developed with carbon nanotube-sheathed carbon fiber microelectrode that offers remarkable selectivity and temporal/spatial resolution for monitoring ascorbate, we observed a substantial efflux of ascorbate in response to hypoxic stress in live rat brain. Furthermore, using a small molecule compound as channel inhibitor to investigate the behavior of ascorbate efflux, we found that this efflux is closely correlated with N-methyl-D-aspartic acid receptor-induced neuronal excitability. Notably, antagonistic actions on volume-sensitive anion channel can suppress ascorbate efflux evoked by hypoxic stress, further revealing that ascorbate fluctuation is volume-sensitive anion channel-dependent. This research not only facilitates a greater understanding of the neurochemical mechanism in hypoxia but also uncovers a potential biomarker for future closed-loop therapies.
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Affiliation(s)
- Ziyang Qi
- School of Education and Psychology, University of Jinan, Jinan, 250022, China
| | - Xingshuai Chen
- School of Physical Education, University of Jinan, Jinan, 250022, China
| | - Ye Zhu
- Shenzhen Research Institute of Shandong University, Shenzhen, 518000, China
| | - Qingwei Yue
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China.
| | - Wenliang Ji
- School of Physical Education, University of Jinan, Jinan, 250022, China.
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Woubshete M, Chan LI, Diallinas G, Byrne B. The dimer of human SVCT1 is key for transport function. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184390. [PMID: 39369805 DOI: 10.1016/j.bbamem.2024.184390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 08/06/2024] [Accepted: 10/03/2024] [Indexed: 10/08/2024]
Abstract
Humans and other primates lack the ability to synthesize the essential nutrient, Vitamin C, which is derived exclusively from the diet. Crucial for effective vitamin C uptake are the Na+ dependent Vitamin C transporters, SVCT1 and SVCT2, members of the nucleobase ascorbate transporter (NAT) family. SVCT1 and 2 actively transport the reduced form of Vitamin C, ascorbic acid, into key tissues. The recent structure of the mouse SVCT1 revealed the molecular basis of substrate binding and that, like the other structurally characterised members of the NAT family, it exists as a closely associated dimer. SVCT1 is likely to function via the elevator mechanism with the core domain of each protomer able to bind substrate and move through the membrane carrying the substrate across the membrane. Here we explored the function of a range of variants of the human SVCT1, revealing a range of residues involved in substrate selection and binding, and confirming the importance of the C-terminus in membrane localisation. Furthermore, using a dominant negative mutant we show that the dimer is essential for transport function, as previously seen in the fungal homologue, UapA. In addition, we show that a localisation deficient C-terminal truncation of SVCT1 blocks correct localisation of co-expressed, associated wildtype SVCT1. These results clearly show the importance of the dimer in both correct SVCT1 trafficking and transport activity.
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Affiliation(s)
- Menebere Woubshete
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Lok I Chan
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, 15784 Athens, Greece; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, 70013 Heraklion, Greece
| | - Bernadette Byrne
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
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Cao Q, Hong A, Chen M, Wang C, Zhu M, Liang X. The association between vitamin C and depressive risk based on the National Health and Nutrition Examination Survey of 2017-2018 and Mendelian randomization study. Am J Transl Res 2024; 16:5137-5149. [PMID: 39398569 PMCID: PMC11470305 DOI: 10.62347/fxxd5655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Accepted: 08/25/2024] [Indexed: 10/15/2024]
Abstract
OBJECTIVES There is some debate about the link between vitamin C and depressive risk. This study utilized data from the National Health and Nutrition Examination Survey (NHANES) and Mendelian randomization (MR) methodology to investigate the association between the two. METHODS We obtained serum vitamin C levels through laboratory data and determined the intake of vitamin C through a 24-hour dietary recall method on the first day from NHANES 2017 to 2018. Assessment of depressive risk was employed by the 9-item Patient Health Questionnaire (PHQ-9). The association between serum vitamin C levels and depressive risk was examined using logistic regression. Furthermore, the research utilized a two-sample MR methodology to investigate the potential causal connection between vitamin C and depressive risk. RESULTS Three thousand four hundred and thirty-four participants aged 20+ with serum vitamin C levels and depressive risk data was included. Among the participants, 18.7% had low serum vitamin C levels and 25.2% had self-reported depressive risk. Serum vitamin C levels were associated with depressive risk [OR 1.64, (95% CI: 1.36-1.97), P < 0.01], which remained significant [OR 1.32, (95% CI: 1.08-1.61), P < 0.01] after adjustments. Distinct genetic SNPs were identified for serum vitamin C levels and depressive risk, allowing detailed analysis. No additional influences were observed between genetic variations. IVW and MR Egger analysis showed a non-causal association between vitamin C levels and depressive risk (All P > 0.05). CONCLUSIONS Our findings of the nationally representative survey revealed a strong correlation between serum levels, intake as a supplement or medication of vitamin C and depressive risk, however, without a unidirectional causal association.
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Affiliation(s)
- Qian Cao
- Department of Anesthesiology, Jiangnan University Medical CenterWuxi, Jiangsu, China
| | - Aonan Hong
- Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing University of Chinese MedicineNanjing, Jiangsu, China
| | - Ming Chen
- Department of Orthopedic, Jiangnan University Medical CenterWuxi, Jiangsu, China
| | - Chunhui Wang
- Department of Anesthesiology, Yixing People’s HospitalYixing, Jiangsu, China
| | - Minmin Zhu
- Department of Anesthesiology, Jiangnan University Medical CenterWuxi, Jiangsu, China
| | - Xiao Liang
- Department of Anesthesiology, Jiangnan University Medical CenterWuxi, Jiangsu, China
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Saldivia N, Salazar K, Cifuentes M, Espinoza F, Harrison FE, Nualart F. Ascorbic acid and its transporter SVCT2, affect radial glia cells differentiation in postnatal stages. Glia 2024; 72:708-727. [PMID: 38180226 DOI: 10.1002/glia.24498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 12/03/2023] [Accepted: 12/10/2023] [Indexed: 01/06/2024]
Abstract
Radial glia (RG) cells generate neurons and glial cells that make up the cerebral cortex. Both in rodents and humans, these stem cells remain for a specific time after birth, named late radial glia (lRG). The knowledge of lRG and molecules that may be involved in their differentiation is based on very limited data. We analyzed whether ascorbic acid (AA) and its transporter SVCT2, are involved in lRG cells differentiation. We demonstrated that lRG cells are highly present between the first and fourth postnatal days. Anatomical characterization of lRG cells, revealed that lRG cells maintained their bipolar morphology and stem-like character. When lRG cells were labeled with adenovirus-eGFP at 1 postnatal day, we detected that some cells display an obvious migratory neuronal phenotype, suggesting that lRG cells continue generating neurons postnatally. Moreover, we demonstrated that SVCT2 was apically polarized in lRG cells. In vitro studies using the transgenic mice SVCT2+/- and SVCT2tg (SVCT2-overexpressing mouse), showed that decreased SVCT2 levels led to accelerated differentiation into astrocytes, whereas both AA treatment and elevated SVCT2 expression maintain the lRG cells in an undifferentiated state. In vivo overexpression of SVCT2 in lRG cells generated cells with a rounded morphology that were migratory and positive for proliferation and neuronal markers. We also examined mediators that can be involved in AA/SVCT2-modulated signaling pathways, determining that GSK3-β through AKT, mTORC2, and PDK1 is active in brains with high levels of SVCT2/AA. Our data provide new insights into the role of AA and SVCT2 in late RG cells.
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Affiliation(s)
- Natalia Saldivia
- Laboratory of Neurobiology and Stem Cells, NeuroCellT, Department of Cellular Biology, Center for Advanced Microscopy, CMA BIO BIO, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Katterine Salazar
- Laboratory of Neurobiology and Stem Cells, NeuroCellT, Department of Cellular Biology, Center for Advanced Microscopy, CMA BIO BIO, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Manuel Cifuentes
- Department of Cell Biology, Genetics and Physiology, Universidad de Málaga, IBIMA, Málaga, Spain
| | - Francisca Espinoza
- Laboratory of Neurobiology and Stem Cells, NeuroCellT, Department of Cellular Biology, Center for Advanced Microscopy, CMA BIO BIO, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Fiona E Harrison
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, USA
| | - Francisco Nualart
- Laboratory of Neurobiology and Stem Cells, NeuroCellT, Department of Cellular Biology, Center for Advanced Microscopy, CMA BIO BIO, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
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Zhong Y, Wang G, Yang S, Zhang Y, Wang X. The role of DNA damage in neural stem cells ageing. J Cell Physiol 2024; 239:e31187. [PMID: 38219047 DOI: 10.1002/jcp.31187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 11/17/2023] [Accepted: 12/20/2023] [Indexed: 01/15/2024]
Abstract
Neural stem cells (NSCs) are pluripotent stem cells with the potential to differentiate into a variety of nerve cells. NSCs are susceptible to both intracellular and extracellular insults, thus causing DNA damage. Extracellular insults include ultraviolet, ionizing radiation, base analogs, modifiers, alkyl agents and others, while intracellular factors include Reactive oxygen species (ROS) radicals produced by mitochondria, mismatches that occur during DNA replication, deamination of bases, loss of bases, and more. When encountered with DNA damage, cells typically employ three coping strategies: DNA repair, damage tolerance, and apoptosis. NSCs, like many other stem cells, have the ability to divide, differentiate, and repair DNA damage to prevent mutations from being passed down to the next generation. However, when DNA damage accumulates over time, it will lead to a series of alterations in the metabolism of cells, which will cause cellular ageing. The ageing and exhaustion of neural stem cell will have serious effects on the body, such as neurodegenerative diseases. The purpose of this review is to examine the processes by which DNA damage leads to NSCs ageing and the mechanisms of DNA repair in NSCs.
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Affiliation(s)
- Yiming Zhong
- School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Guangming Wang
- School of Medicine, Postdoctoral Station of Clinical Medicine, Shanghai Tongji Hospital, Tongji University, Shanghai, China
| | - Shangzhi Yang
- School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yang Zhang
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Xianli Wang
- School of Public Health, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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Portugal CC. Ascorbate and its transporter SVCT2: The dynamic duo's integrated roles in CNS neurobiology and pathophysiology. Free Radic Biol Med 2024; 212:448-462. [PMID: 38182073 DOI: 10.1016/j.freeradbiomed.2023.12.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 12/11/2023] [Accepted: 12/27/2023] [Indexed: 01/07/2024]
Abstract
Ascorbate is a small antioxidant molecule essential for the proper development and function of the brain. Ascorbate is transported into the brain and between brain cells via the Sodium vitamin C co-transporter 2 (SVCT2). This review provides an in-depth analysis of ascorbate's physiology, including how ascorbate is absorbed from food into the CNS, emphasizing cellular mechanisms of ascorbate recycling and release in different CNS compartments. Additionally, the review delves into the various functions of ascorbate in the CNS, including its impact on epigenetic modulation, synaptic plasticity, and neurotransmission. It also emphasizes ascorbate's role on neuromodulation and its involvement in neurodevelopmental processes and disorders. Furthermore, it analyzes the relationship between the duo ascorbate/SVCT2 in neuroinflammation, particularly its effects on microglial activation, cytokine release, and oxidative stress responses, highlighting its association with neurodegenerative diseases, such as Alzheimer's disease (AD). Overall, this review emphasizes the crucial role of the dynamic duo ascorbate/SVCT2 in CNS physiology and pathology and the need for further research to fully comprehend its significance in a neurobiological context and its potential therapeutic applications.
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Affiliation(s)
- Camila C Portugal
- I3s - Instituto de Investigação e Inovação em Saúde da Universidade do Porto and IBMC - Instituto de Biologia Molecular e Celular, Rua Alfredo Allen 208, 4200-135, Porto, Portugal.
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