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Okamoto Y, Takashima H. The Current State of Charcot-Marie-Tooth Disease Treatment. Genes (Basel) 2023; 14:1391. [PMID: 37510296 PMCID: PMC10379063 DOI: 10.3390/genes14071391] [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: 05/28/2023] [Revised: 06/20/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023] Open
Abstract
Charcot-Marie-Tooth disease (CMT) and associated neuropathies are the most predominant genetically transmitted neuromuscular conditions; however, effective pharmacological treatments have not established. The extensive genetic heterogeneity of CMT, which impacts the peripheral nerves and causes lifelong disability, presents a significant barrier to the development of comprehensive treatments. An estimated 100 loci within the human genome are linked to various forms of CMT and its related inherited neuropathies. This review delves into prospective therapeutic strategies used for the most frequently encountered CMT variants, namely CMT1A, CMT1B, CMTX1, and CMT2A. Compounds such as PXT3003, which are being clinically and preclinically investigated, and a broad array of therapeutic agents and their corresponding mechanisms are discussed. Furthermore, the progress in established gene therapy techniques, including gene replacement via viral vectors, exon skipping using antisense oligonucleotides, splicing modification, and gene knockdown, are appraised. Each of these gene therapies has the potential for substantial advancements in future research.
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Affiliation(s)
- Yuji Okamoto
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
- Department of Physical Therapy, School of Health Sciences, Faculty of Medicine, Kagoshima University, Kagoshima 890-8544, Japan
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
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2
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In vitro effects of vitamins C and E on adipocyte function and redox status in obesity. PHARMANUTRITION 2022. [DOI: 10.1016/j.phanu.2022.100315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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3
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Opioids and Vitamin C: Known Interactions and Potential for Redox-Signaling Crosstalk. Antioxidants (Basel) 2022; 11:antiox11071267. [PMID: 35883757 PMCID: PMC9312198 DOI: 10.3390/antiox11071267] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/17/2022] [Accepted: 06/21/2022] [Indexed: 12/10/2022] Open
Abstract
Opioids are among the most widely used classes of pharmacologically active compounds both clinically and recreationally. Beyond their analgesic efficacy via μ opioid receptor (MOR) agonism, a prominent side effect is central respiratory depression, leading to systemic hypoxia and free radical generation. Vitamin C (ascorbic acid; AA) is an essential antioxidant vitamin and is involved in the recycling of redox cofactors associated with inflammation. While AA has been shown to reduce some of the negative side effects of opioids, the underlying mechanisms have not been explored. The present review seeks to provide a signaling framework under which MOR activation and AA may interact. AA can directly quench reactive oxygen and nitrogen species induced by opioids, yet this activity alone does not sufficiently describe observations. Downstream of MOR activation, confounding effects from AA with STAT3, HIF1α, and NF-κB have the potential to block production of antioxidant proteins such as nitric oxide synthase and superoxide dismutase. Further mechanistic research is necessary to understand the underlying signaling crosstalk of MOR activation and AA in the amelioration of the negative, potentially fatal side effects of opioids.
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4
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Miniou P, Fontes M. Therapeutic Development in Charcot Marie Tooth Type 1 Disease. Int J Mol Sci 2021; 22:ijms22136755. [PMID: 34201736 PMCID: PMC8268813 DOI: 10.3390/ijms22136755] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 01/04/2023] Open
Abstract
Charcot–Marie–Tooth disease (CMT) is the most frequent hereditary peripheral neuropathies. It is subdivided in two main groups, demyelinating (CMT1) and axonal (CMT2). CMT1 forms are the most frequent. The goal of this review is to present published data on 1—cellular and animal models having opened new potential therapeutic approaches. 2—exploration of these tracks, including clinical trials. The first conclusion is the great increase of publications on CMT1 subtypes since 2000. We discussed two points that should be considered in the therapeutic development toward a regulatory-approved therapy to be proposed to patients. The first point concerns long term safety if treatments will be a long-term process. The second point relates to the evaluation of treatment efficiency. Degradation of CMT clinical phenotype is not linear and progressive.
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Affiliation(s)
- Pierre Miniou
- InFlectis BioScience SAS, 21 Rue La Noue Bras de Fer, 44200 Nantes, France;
| | - Michel Fontes
- Centre de recherche en CardioVasculaire et Nutrition, Aix-Marseille Université, INRA 1260—INSERM 1263, 13005 Marseille, France
- Repositioning SAS, 8 Rue Napoleon, 20210 Calenzana, France
- Correspondence:
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5
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Stavrou M, Sargiannidou I, Georgiou E, Kagiava A, Kleopa KA. Emerging Therapies for Charcot-Marie-Tooth Inherited Neuropathies. Int J Mol Sci 2021; 22:6048. [PMID: 34205075 PMCID: PMC8199910 DOI: 10.3390/ijms22116048] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 12/12/2022] Open
Abstract
Inherited neuropathies known as Charcot-Marie-Tooth (CMT) disease are genetically heterogeneous disorders affecting the peripheral nerves, causing significant and slowly progressive disability over the lifespan. The discovery of their diverse molecular genetic mechanisms over the past three decades has provided the basis for developing a wide range of therapeutics, leading to an exciting era of finding treatments for this, until now, incurable group of diseases. Many treatment approaches, including gene silencing and gene replacement therapies, as well as small molecule treatments are currently in preclinical testing while several have also reached clinical trial stage. Some of the treatment approaches are disease-specific targeted to the unique disease mechanism of each CMT form, while other therapeutics target common pathways shared by several or all CMT types. As promising treatments reach the stage of clinical translation, optimal outcome measures, novel biomarkers and appropriate trial designs are crucial in order to facilitate successful testing and validation of novel treatments for CMT patients.
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Affiliation(s)
- Marina Stavrou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Irene Sargiannidou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Elena Georgiou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Alexia Kagiava
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
| | - Kleopas A. Kleopa
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus; (M.S.); (I.S.); (E.G.); (A.K.)
- Center for Neuromuscular Diseases, The Cyprus Institute of Neurology and Genetics, Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus
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6
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Boutary S, Echaniz-Laguna A, Adams D, Loisel-Duwattez J, Schumacher M, Massaad C, Massaad-Massade L. Treating PMP22 gene duplication-related Charcot-Marie-Tooth disease: the past, the present and the future. Transl Res 2021; 227:100-111. [PMID: 32693030 DOI: 10.1016/j.trsl.2020.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 07/02/2020] [Accepted: 07/15/2020] [Indexed: 12/30/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease is the most frequent inherited neuropathy, affecting 1/1500 to 1/10000. CMT1A represents 60%-70% of all CMT and is caused by a duplication on chromosome 17p11.2 leading to an overexpression of the Peripheral Myelin Protein 22 (PMP22). PMP22 gene is under tight regulation and small changes in its expression influences myelination and affect motor and sensory functions. To date, CMT1A treatment is symptomatic and classic pharmacological options have been disappointing. Here, we review the past, present, and future treatment options for CMT1A, with a special emphasis on the highly promising potential of PMP22-targeted small interfering RNA and antisense oligonucleotides.
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Affiliation(s)
- Suzan Boutary
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France
| | - Andoni Echaniz-Laguna
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | - David Adams
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | - Julien Loisel-Duwattez
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | | | - Charbel Massaad
- Faculty of Basic and Biomedical Sciences, Paris Descartes University, INSERM UMRS 1124, Paris, France
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7
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A comprehensive mechanistic review insight into the effects of micronutrients on toll-like receptors functions. Pharmacol Res 2019; 152:104619. [PMID: 31887355 DOI: 10.1016/j.phrs.2019.104619] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/23/2019] [Accepted: 12/26/2019] [Indexed: 12/29/2022]
Abstract
Toll-like receptors (TLRs) are the special proteins receptors for recognition of molecules related to the pathogens. In this way, TLRs and secreted cytokines as a result of TLRs activation are involved in the inflammation pathways. So far, in vivo and in vitro studies have demonstrated that micronutrients (vitamins & minerals) with a broad range of effects on body health, can regulate TLRs signaling pathways. Current review aimed at determining the possible mechanisms of micronutrient effects on TLRs functions. In the aspect of gene expression, micronutrients have inconsistent effects on mRNA level of TLRs which are dependent on time, dose and type of studied TLR. Also, some micronutrients affect gene expression of TLRs signaling mediators namely TLRs adaptors like Myeloid differentiation primary response 88 (MyD88). In the aspect of TLRs signaling pathways, nuclear factor-κB (NF-κB) is an important mediator which is regulated by micronutrients. Also, the regulatory effects of micronutrients on phosphorylation reactions may be effective in the activation/inactivation of TLRs signaling mediators. In addition, zinc can regulate TLRs signaling indirectly via the zinc finger proteins which have contradictory effects on TLRs cascade. In conclusion, the relationship between micronutrients and TLRs signaling is complicated and depends on some known internal, external and genetic factors like form of studied micronutrient, cell type, TLR agonist, dose and time of exposure, inflammation, apoptosis, cell cycle, and environmental factors. Some unknown factors may be effective in TLRs response and as a result additional mechanistic studies are needed to elucidate exact effect of micronutrients on TLRs signaling.
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8
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Kiepura AJ, Kochański A. Charcot-Marie-Tooth type 1A drug therapies: role of adenylyl cyclase activity and G-protein coupled receptors in disease pathomechanism. Acta Neurobiol Exp (Wars) 2018. [DOI: 10.21307/ane-2018-018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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9
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Domith I, Socodato R, Portugal CC, Munis AF, Duarte-Silva AT, Paes-de-Carvalho R. Vitamin C modulates glutamate transport and NMDA receptor function in the retina. J Neurochem 2017; 144:408-420. [PMID: 29164598 DOI: 10.1111/jnc.14260] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 11/09/2017] [Accepted: 11/11/2017] [Indexed: 12/27/2022]
Abstract
Vitamin C (in the reduced form ascorbate or in the oxidized form dehydroascorbate) is implicated in signaling events throughout the central nervous system (CNS). In the retina, a high-affinity transport system for ascorbate has been described and glutamatergic signaling has been reported to control ascorbate release. Here, we investigated the modulatory role played by vitamin C upon glutamate uptake and N-methyl-d-aspartate (NMDA) receptor activation in cultured retinal cells or in intact retinal tissue using biochemical and imaging techniques. We show that both forms of vitamin C, ascorbate or dehydroascorbate, promote an accumulation of extracellular glutamate by a mechanism involving the inhibition of glutamate uptake. This inhibition correlates with the finding that ascorbate promotes a decrease in cell surface levels of the neuronal glutamate transporter excitatory amino acid transporter 3 in retinal neuronal cultures. Interestingly, vitamin C is prone to increase the activity of NMDA receptors but also promotes a decrease in glutamate-stimulated [3 H] MK801 binding and decreases cell membrane content of NMDA receptor glutamate ionotropic receptor subunit 1 (GluN1) subunits. Both compounds were also able to increase cAMP response element-binding protein phosphorylation in neuronal nuclei in a glutamate receptor and calcium/calmodulin kinase-dependent manner. Moreover, the effect of ascorbate is not blocked by sulfinpyrazone and then does not depend on its uptake by retinal cells. Overall, these data indicate a novel molecular and functional target for vitamin C impacting on glutamate signaling in retinal neurons.
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Affiliation(s)
- Ivan Domith
- Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil
| | - Renato Socodato
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Camila C Portugal
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Andressa F Munis
- Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil
| | - Aline T Duarte-Silva
- Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil
| | - Roberto Paes-de-Carvalho
- Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil.,Department of Neurobiology, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil
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10
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Vitamin C in Stem Cell Biology: Impact on Extracellular Matrix Homeostasis and Epigenetics. Stem Cells Int 2017; 2017:8936156. [PMID: 28512473 PMCID: PMC5415867 DOI: 10.1155/2017/8936156] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 03/05/2017] [Indexed: 12/30/2022] Open
Abstract
Transcription factors and signaling molecules are well-known regulators of stem cell identity and behavior; however, increasing evidence indicates that environmental cues contribute to this complex network of stimuli, acting as crucial determinants of stem cell fate. l-Ascorbic acid (vitamin C (VitC)) has gained growing interest for its multiple functions and mechanisms of action, contributing to the homeostasis of normal tissues and organs as well as to tissue regeneration. Here, we review the main functions of VitC and its effects on stem cells, focusing on its activity as cofactor of Fe+2/αKG dioxygenases, which regulate the epigenetic signatures, the redox status, and the extracellular matrix (ECM) composition, depending on the enzymes' subcellular localization. Acting as cofactor of collagen prolyl hydroxylases in the endoplasmic reticulum, VitC regulates ECM/collagen homeostasis and plays a key role in the differentiation of mesenchymal stem cells towards osteoblasts, chondrocytes, and tendons. In the nucleus, VitC enhances the activity of DNA and histone demethylases, improving somatic cell reprogramming and pushing embryonic stem cell towards the naive pluripotent state. The broad spectrum of actions of VitC highlights its relevance for stem cell biology in both physiology and disease.
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11
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Batra SD, Nandi M, Sikri K, Tyagi JS. Genome-wide expression profiling establishes novel modulatory roles of vitamin C in THP-1 human monocytic cell line. BMC Genomics 2017; 18:252. [PMID: 28335738 PMCID: PMC5364625 DOI: 10.1186/s12864-017-3635-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 03/16/2017] [Indexed: 12/12/2022] Open
Abstract
Background Vitamin C (vit C) is an essential dietary nutrient, which is a potent antioxidant, a free radical scavenger and functions as a cofactor in many enzymatic reactions. Vit C is also considered to enhance the immune effector function of macrophages, which are regarded to be the first line of defence in response to any pathogen. The THP-1 cell line is widely used for studying macrophage functions and for analyzing host cell-pathogen interactions. Results We performed a genome-wide temporal gene expression and functional enrichment analysis of THP-1 cells treated with 100 μM of vit C, a physiologically relevant concentration of the vitamin. Modulatory effects of vitamin C on THP-1 cells were revealed by differential expression of genes starting from 8 h onwards. The number of differentially expressed genes peaked at the earliest time-point i.e. 8 h followed by temporal decline till 96 h. Further, functional enrichment analysis based on statistically stringent criteria revealed a gamut of functional responses, namely, ‘Regulation of gene expression’, ‘Signal transduction’, ‘Cell cycle’, ‘Immune system process’, ‘cAMP metabolic process’, ‘Cholesterol transport’ and ‘Ion homeostasis’. A comparative analysis of vit C-mediated modulation of gene expression data in THP-1cells and human skin fibroblasts disclosed an overlap in certain functional processes such as ‘Regulation of transcription’, ‘Cell cycle’ and ‘Extracellular matrix organization’, and THP-1 specific responses, namely, ‘Regulation of gene expression’ and ‘Ion homeostasis’. It was noteworthy that vit C modulated the ‘Immune system’ process throughout the time-course. Conclusions This study reveals the genome-wide effects of physiological levels of vit C on THP-1 gene expression. The multitude of effects impacted by vit C in macrophages highlights its role in maintaining homeostasis of several cellular functions. This study provides a rational basis for the use of the Vitamin C- THP-1 cell model, to study biochemical and cellular responses to stresses, including infection with M. tuberculosis and other intracellular pathogens. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3635-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sakshi Dhingra Batra
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Malobi Nandi
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Kriti Sikri
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Jaya Sivaswami Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, 110029, India.
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Rahman F, Bordignon B, Culerrier R, Peiretti F, Spicuglia S, Djabali M, Landrier JF, Fontes M. Ascorbic acid drives the differentiation of mesoderm-derived embryonic stem cells. Involvement of p38 MAPK/CREB and SVCT2 transporter. Mol Nutr Food Res 2017; 61. [DOI: 10.1002/mnfr.201600506] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Revised: 10/28/2016] [Accepted: 11/03/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Fryad Rahman
- NORT. UMR INSERM 1062, INRA 1260; Aix-Marseille University; Marseille Cedex 5 France
- Department of Biology, Faculty of Science; University of Sulaimani; Sulaimani Kurdistan Region Iraq
| | - Benoit Bordignon
- NORT. UMR INSERM 1062, INRA 1260; Aix-Marseille University; Marseille Cedex 5 France
| | - Raphael Culerrier
- CNRS-UMR 5088/University of Toulouse-3; Université-Paul-Sabatier; Toulouse Cedex France
| | - Franck Peiretti
- NORT. UMR INSERM 1062, INRA 1260; Aix-Marseille University; Marseille Cedex 5 France
| | | | - Malek Djabali
- CNRS-UMR 5088/University of Toulouse-3; Université-Paul-Sabatier; Toulouse Cedex France
| | | | - Michel Fontes
- NORT. UMR INSERM 1062, INRA 1260; Aix-Marseille University; Marseille Cedex 5 France
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13
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Parker WH, Qu ZC, May JM. Intracellular Ascorbate Prevents Endothelial Barrier Permeabilization by Thrombin. J Biol Chem 2015; 290:21486-97. [PMID: 26152729 DOI: 10.1074/jbc.m115.662098] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Indexed: 12/11/2022] Open
Abstract
Intracellular ascorbate (vitamin C) has previously been shown to tighten the endothelial barrier and maintain barrier integrity during acute inflammation in vitro. However, the downstream effectors of ascorbate in the regulation of endothelial permeability remain unclear. In this study, we evaluated ascorbate as a mediator of thrombin-induced barrier permeabilization in human umbilical vein endothelial cells and their immortalized hybridoma line, EA.hy926. We found that the vitamin fully prevented increased permeability to the polysaccharide inulin by thrombin in a dose-dependent manner, and it took effect both before and after subjection to thrombin. Thrombin exposure consumed intracellular ascorbate but not the endogenous antioxidant GSH. Likewise, the antioxidants dithiothreitol and tempol did not reverse permeabilization. We identified a novel role for ascorbate in preserving cAMP during thrombin stimulation, resulting in two downstream effects. First, ascorbate maintained the cortical actin cytoskeleton in a Rap1- and Rac1-dependent manner, thus preserving stable adherens junctions between adjacent cells. Second, ascorbate prevented actin polymerization and formation of stress fibers by reducing the activation of RhoA and phosphorylation of myosin light chain. Although ascorbate and thrombin both required calcium for their respective effects, ascorbate did not prevent thrombin permeabilization by obstructing calcium influx. However, preservation of cAMP by ascorbate was found to depend on both the production of nitric oxide by endothelial nitric-oxide synthase, which ascorbate is known to activate, and the subsequent generation cGMP by guanylate cyclase. Together, these data implicate ascorbate in the prevention of inflammatory endothelial barrier permeabilization and explain the underlying signaling mechanism.
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Affiliation(s)
- William H Parker
- From the Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6303
| | - Zhi-chao Qu
- From the Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6303
| | - James M May
- From the Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6303
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Ekins S, Litterman NK, Arnold RJG, Burgess RW, Freundlich JS, Gray SJ, Higgins JJ, Langley B, Willis DE, Notterpek L, Pleasure D, Sereda MW, Moore A. A brief review of recent Charcot-Marie-Tooth research and priorities. F1000Res 2015; 4:53. [PMID: 25901280 PMCID: PMC4392824 DOI: 10.12688/f1000research.6160.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/24/2015] [Indexed: 12/14/2022] Open
Abstract
This brief review of current research progress on Charcot-Marie-Tooth (CMT) disease is a summary of discussions initiated at the Hereditary Neuropathy Foundation (HNF) scientific advisory board meeting on November 7, 2014. It covers recent published and unpublished
in vitro and
in vivo research. We discuss recent promising preclinical work for CMT1A, the development of new biomarkers, the characterization of different animal models, and the analysis of the frequency of gene mutations in patients with CMT. We also describe how progress in related fields may benefit CMT therapeutic development, including the potential of gene therapy and stem cell research. We also discuss the potential to assess and improve the quality of life of CMT patients. This summary of CMT research identifies some of the gaps which may have an impact on upcoming clinical trials. We provide some priorities for CMT research and areas which HNF can support. The goal of this review is to inform the scientific community about ongoing research and to avoid unnecessary overlap, while also highlighting areas ripe for further investigation. The general collaborative approach we have taken may be useful for other rare neurological diseases.
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Affiliation(s)
- Sean Ekins
- Hereditary Neuropathy Foundation, New York, NY, 10016, USA ; Collaborations in Chemistry, Fuquay Varina, NC, 27526, USA ; Collaborative Drug Discovery, Burlingame, CA, 94010, USA
| | | | - Renée J G Arnold
- Arnold Consultancy & Technology LLC, New York, NY, 10023, USA ; Master of Public Health Program, Mount Sinai School of Medicine, New York, NY, 10029, USA ; Quorum Consulting, Inc, San Francisco, CA, 94104, USA
| | - Robert W Burgess
- The Jackson Laboratory in Bar Harbor, Bar Harbour, ME, 04609, USA
| | - Joel S Freundlich
- Department of Medicine, Center for Emerging and Reemerging Pathogens, Rutgers University - New Jersey Medical School, Newark, NJ, 07103, USA
| | - Steven J Gray
- Gene Therapy Center and Dept. of Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-7352, USA
| | | | - Brett Langley
- Burke-Cornell Medical Research Institute, White Plains, NY, 10605, USA ; Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY, 10065, USA
| | - Dianna E Willis
- Burke-Cornell Medical Research Institute, White Plains, NY, 10605, USA
| | - Lucia Notterpek
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, FL, 32611, USA
| | - David Pleasure
- Institute for Pediatric Regenerative Medicine, University of California Davis, School of Medicine, Sacramento, CA, 95817, USA ; Department of Neurology, University of California, Davis, School of Medicine, c/o Shriners Hospital, Sacramento, CA, 95817, USA
| | - Michael W Sereda
- Department of Neurogenetics, Max Planck Institute (MPI) of Experimental Medicine, Göttingen, 37075, Germany ; Department of Clinical Neurophysiology, University Medical Center (UMG), Göttingen, D-37075, Germany
| | - Allison Moore
- Hereditary Neuropathy Foundation, New York, NY, 10016, USA
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15
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Brewer MH, Ma KH, Beecham GW, Gopinath C, Baas F, Choi BO, Reilly MM, Shy ME, Züchner S, Svaren J, Antonellis A. Haplotype-specific modulation of a SOX10/CREB response element at the Charcot-Marie-Tooth disease type 4C locus SH3TC2. Hum Mol Genet 2014; 23:5171-87. [PMID: 24833716 PMCID: PMC4168306 DOI: 10.1093/hmg/ddu240] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/01/2014] [Accepted: 05/12/2014] [Indexed: 12/22/2022] Open
Abstract
Loss-of-function mutations in the Src homology 3 (SH3) domain and tetratricopeptide repeats 2 (SH3TC2) gene cause autosomal recessive demyelinating Charcot-Marie-Tooth neuropathy. The SH3TC2 protein has been implicated in promyelination signaling through axonal neuregulin-1 and the ERBB2 Schwann cell receptor. However, little is known about the transcriptional regulation of the SH3TC2 gene. We performed computational and functional analyses that revealed two cis-acting regulatory elements at SH3TC2-one at the promoter and one ∼150 kb downstream of the transcription start site. Both elements direct reporter gene expression in Schwann cells and are responsive to the transcription factor SOX10, which is essential for peripheral nervous system myelination. The downstream enhancer harbors a single-nucleotide polymorphism (SNP) that causes an ∼80% reduction in enhancer activity. The SNP resides directly within a predicted binding site for the transcription factor cAMP response element binding protein (CREB), and we demonstrate that this regulatory element binds to CREB and is activated by CREB expression. Finally, forskolin induces Sh3tc2 expression in rat primary Schwann cells, indicating that SH3TC2 is a CREB target gene. These findings prompted us to determine if SNP genotypes at SH3TC2 are associated with differential phenotypes in the most common demyelinating peripheral neuropathy, CMT1A. Interestingly, this revealed several associations between SNP alleles and disease severity. In summary, our data indicate that SH3TC2 is regulated by the transcription factors CREB and SOX10, define a regulatory SNP at this disease-associated locus and reveal SH3TC2 as a candidate modifier locus of CMT disease phenotypes.
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Affiliation(s)
| | - Ki Hwan Ma
- Cellular and Molecular Pathology (CMP) Program
| | - Gary W Beecham
- Dr John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Chetna Gopinath
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Frank Baas
- Department of Genome Analysis, Academic Medical Centre, Amsterdam, The Netherlands
| | - Byung-Ok Choi
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Gangnam-Gu, Seoul, Korea
| | - Mary M Reilly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, Queen Square, London, UK
| | - Michael E Shy
- Department of Neurology Department of Pediatrics and Department of Physiology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Stephan Züchner
- Dr John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - John Svaren
- Waisman Center and Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Anthony Antonellis
- Department of Human Genetics Department of Neurology and Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, USA
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Low in vitro permeability of the cyanotoxin microcystin-LR across a Caco-2 monolayer: with identification of the limiting factors using modelling. Toxicon 2014; 91:5-14. [PMID: 25110175 DOI: 10.1016/j.toxicon.2014.07.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/29/2014] [Accepted: 07/31/2014] [Indexed: 01/25/2023]
Abstract
Microcystins (MCs) are toxins produced by several cyanobacteria species found worldwide. MC-LR is the most frequent. Here, we used the human Caco-2 cell line grown on semi-permeable filter supports as an in vitro model for determining MC-LR intestinal bidirectional transport. In this study, there was very low and time-dependent apparent permeability of MC-LR. To identify the limiting factors involved in the low permeability of MC-LR, a mathematical model was constructed to get physiologically relevant and informative parameters. The apical-to-basolateral transport was characterised by a rapid and substantial decrease in apical MC-LR concentrations (24-40% of the initial amount). In the basolateral compartment, the concentrations increased slowly after a lag time, but represented only a small fraction of the loaded concentrations (0.3-1.3%) after 24 h. This weak permeability was mainly due to a low clearance of efflux (from the cellular to the basolateral compartment) and effective secretion (from the cellular to the apical compartment). During the basolateral-to-apical transport, we observed a slow decrease in basolateral concentrations and a rapid increase in apical concentrations. In conclusion, modelling has the potential to highlight the key mechanisms involved in the complex kinetics of toxin transport.
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Rahman F, Al Frouh F, Bordignon B, Fraterno M, Landrier JF, Peiretti F, Fontes M. Ascorbic acid is a dose-dependent inhibitor of adipocyte differentiation, probably by reducing cAMP pool. Front Cell Dev Biol 2014; 2:29. [PMID: 25364736 PMCID: PMC4207035 DOI: 10.3389/fcell.2014.00029] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 06/29/2014] [Indexed: 12/14/2022] Open
Abstract
Ascorbic acid (AA) is the active component of vitamin C and antioxidant activity was long considered to be the primary molecular mechanism underlying the physiological actions of AA. We recently demonstrated that AA is a competitive inhibitor of adenylate cyclase, acting as a global regulator of intracellular cyclic adenosine monophosphate (cAMP) levels. Our study, therefore, aimed to determine new targets of AA that would account for its potential effect on signal transduction, particularly during cell differentiation. We demonstrated that AA is an inhibitor of pre-adipocyte cell line differentiation, with a dose-dependent effect. Additionally, we describe the impact of AA on the expression of genes involved in adipogenesis and/or the adipocyte phenotype. Moreover, our data suggest that treatment with AA partially reverses lipid accumulation in mature adipocytes. These properties likely reflect the function of AA as a global regulator of the cAMP pool, since an analog of AA without any antioxidant properties elicited the same effect. Additionally, we demonstrated that AA inhibits adipogenesis in OP9 mesenchymal cell line and drives the differentiation of this line toward osteogenesis. Finally, our data suggest that the intracellular transporter SVCT2 is involved in these processes and may act as a receptor for AA.
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Affiliation(s)
- Fryad Rahman
- Nutrition, Obesity and Risk of Thrombosis, INSERM U 1062, INRA 1260, Aix-Marseille University Marseille, France
| | - Fadi Al Frouh
- Nutrition, Obesity and Risk of Thrombosis, INSERM U 1062, INRA 1260, Aix-Marseille University Marseille, France
| | - Benoit Bordignon
- Nutrition, Obesity and Risk of Thrombosis, INSERM U 1062, INRA 1260, Aix-Marseille University Marseille, France
| | - Marc Fraterno
- Service of Electron Microscope, Faculté de Médecine, Aix-Marseille University Marseille, France
| | - Jean-François Landrier
- Nutrition, Obesity and Risk of Thrombosis, INSERM U 1062, INRA 1260, Aix-Marseille University Marseille, France
| | - Franck Peiretti
- Nutrition, Obesity and Risk of Thrombosis, INSERM U 1062, INRA 1260, Aix-Marseille University Marseille, France
| | - Michel Fontes
- Nutrition, Obesity and Risk of Thrombosis, INSERM U 1062, INRA 1260, Aix-Marseille University Marseille, France
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Gess B, Röhr D, Young P. Ascorbic acid and sodium-dependent vitamin C transporters in the peripheral nervous system: from basic science to clinical trials. Antioxid Redox Signal 2013; 19:2105-14. [PMID: 23642070 DOI: 10.1089/ars.2013.5380] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
SIGNIFICANCE Ascorbic acid and sodium-dependent vitamin C transporters (SVCT) have been shown to have important functions in the peripheral nervous system (PNS). Ascorbic acid is known to promote myelination in vitro in Schwann cell/dorsal root ganglion co-cultures by the formation of a collagen- and laminin-containing extracellular matrix. RECENT ADVANCES Recently, the function of ascorbic acid and SVCT2 in the PNS has been shown in vivo as well. Several studies on ascorbic acid treatment of Charcot-Marie-Tooth neuropathy 1A (CMT1A) have been completed and showed no clinical benefit. CRITICAL ISSUES Possible reasons for the failure of ascorbic acid in CMT1A treatment are discussed in this review. More preclinical trials, ideally using different animal models, should be considered before the initiation of clinical trials in humans. More knowledge about ascorbic acid transport kinetics and inter-individual differences in humans is necessary for future studies. FUTURE DIRECTIONS Further research into ascorbic acid transport mechanisms in the PNS is warranted. Especially the effects of transgenic or pharmacologic SVCT2 up-regulation on PNS myelination and remyelination will be an interesting area of research in the future. Furthermore, the potential use of ascorbic acid for peripheral neuropathies other than CMT1A would be a possible future research direction.
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Affiliation(s)
- Burkhard Gess
- 1 Department of Neurology, Clinic for Sleep Medicine and Neuromuscular Disorders, University of Muenster , Muenster, Germany
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Bordignon B, Mones S, Rahman F, Chiron J, Peiretti F, Vidal N, Fontes M. A derivative of ascorbic acid modulates cAMP production. Biochem Biophys Res Commun 2013; 439:137-41. [PMID: 23942115 DOI: 10.1016/j.bbrc.2013.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Accepted: 08/03/2013] [Indexed: 11/25/2022]
Abstract
We reported, in previous experiments, that AA is a global regulator of cAMP pools. In this study, we demonstrate that K873, an analog of AA we synthesized and presenting antiproliferative properties, has also an impact on cAMP production. However, K873 has no antioxidant activity, at the contrary of AA. It definitively demonstrates that action of AA on the cAMP production is not linked to antioxidant activity. These data suggest that AA, and derivatives of this molecule, could be promising drug acting on biological processes that are under the control of cAMP dependent pathway.
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Affiliation(s)
- B Bordignon
- N.O.R.T.: Nutrition, Obesity and Risk of Thrombosis, Aix-Marseille University, INSERM U 1062, INRA 1260, 27 boulevard Jean Moulin, F-13385 Marseille, France
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Bordignon B, Chiron J, Fontés M. Ascorbic acid derivatives as a new class of antiproliferative molecules. Cancer Lett 2013; 338:317-27. [PMID: 23791877 DOI: 10.1016/j.canlet.2013.06.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 05/30/2013] [Accepted: 06/02/2013] [Indexed: 01/10/2023]
Abstract
Ascorbic acid (AA) has long been described as an antiproliferative agent. However, the molecule has to be used at a very high concentrations, which necessitates i.v. injection, and the tight regulation of in-blood and in-cell AA concentrations making it impossible to hold very high concentrations for any substantial length of time. Here we report evidence that AA derivates are antiproliferative and cytotoxic molecules at an IC50 lower than AA itself. Among these new molecules, we selected K873 that has cytotoxic and antiproliferative effects on different human tumor cells at tenth micromolar concentration. In a further step, we demonstrated that K873 selectively to kills only cancer cells without being toxic for normal non-dividing (or poorly dividing) cells. Finally, we tested the effect of treatment with K873 (5-10 mg/kg/d by i.p. route) on tumor progression in xenografted immunodeficient mice (BALB/c Nude). Our data suggest that K873 administration strongly inhibits tumor progression. In a previous study using microarrays, we demonstrated that AA decreases the expression of two genes families involved in cell cycle progression, i.e. initiation factor of translation and tRNA synthetases. Here we show that K873 treatment also decreases the expression of four of these genes in xenografted tumors, in proportions similar to that previously observed with AA. Taken together, our data suggest that AA and K873 share similar action. Our findings suggest that AA derivatives could be a promising new class of anti-cancer drugs, either alone or in combination with other molecules.
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Affiliation(s)
- Benoit Bordignon
- Therapy of Genetic Disorders, EA 4263, Aix-Marseille Université (AMU), Faculté de Médecine, 27 Boulevard Jean Moulin, F-13385 Marseille, France
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Li J, Parker B, Martyn C, Natarajan C, Guo J. The PMP22 gene and its related diseases. Mol Neurobiol 2012; 47:673-98. [PMID: 23224996 DOI: 10.1007/s12035-012-8370-x] [Citation(s) in RCA: 167] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 10/22/2012] [Indexed: 10/27/2022]
Abstract
Peripheral myelin protein-22 (PMP22) is primarily expressed in the compact myelin of the peripheral nervous system. Levels of PMP22 have to be tightly regulated since alterations of PMP22 levels by mutations of the PMP22 gene are responsible for >50 % of all patients with inherited peripheral neuropathies, including Charcot-Marie-Tooth type-1A (CMT1A) with trisomy of PMP22, hereditary neuropathy with liability to pressure palsies (HNPP) with heterozygous deletion of PMP22, and CMT1E with point mutations of PMP22. While overexpression and point-mutations of the PMP22 gene may produce gain-of-function phenotypes, deletion of PMP22 results in a loss-of-function phenotype that reveals the normal physiological functions of the PMP22 protein. In this article, we will review the basic genetics, biochemistry and molecular structure of PMP22, followed by discussion of the current understanding of pathogenic mechanisms involving in the inherited neuropathies with mutations in PMP22 gene.
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Affiliation(s)
- Jun Li
- VA Tennessee Valley Healthcare System, 1310 24th Avenue South, Nashville, TN 37212, USA.
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Belin S, Kaya F, Burtey S, Fontes M. Ascorbic Acid and gene expression: another example of regulation of gene expression by small molecules? Curr Genomics 2011; 11:52-7. [PMID: 20808524 PMCID: PMC2851117 DOI: 10.2174/138920210790217936] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 09/24/2009] [Accepted: 10/22/2009] [Indexed: 01/31/2023] Open
Abstract
Ascorbic acid (vitamin C, AA) has long been considered a food supplement necessary for life and for preventing scurvy. However, it has been reported that other small molecules such as retinoic acid (vitamin A) and different forms of calciferol (vitamin D) are directly involved in regulating the expression of numerous genes. These molecules bind to receptors that are differentially expressed in the embryo and are therefore crucial signalling molecules in vertebrate development. The question is: is ascorbic acid also a signalling molecule that regulates gene expression? We therefore present and discuss recent publications that demonstrate that AA regulates the expression of a battery of genes. We offer a clue to understanding the biochemical mechanism by which AA regulates gene expression. Finally we will discuss the question of a receptor for AA and its potential involvement in embryonic development and cell differentiation.
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Affiliation(s)
- Sophie Belin
- Therapy of Genetic Disorders, EA 4263, Faculté de Médecine de la Timone, Université de la Méditerranée, Marseille, France
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Pavan B, Paganetto G, Dalpiaz A. Dopamine-sensitive adenylyl cyclases in neuronal development: physiopathological and pharmacological implications. Drug Discov Today 2011; 16:520-9. [DOI: 10.1016/j.drudis.2011.03.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 02/23/2011] [Accepted: 03/29/2011] [Indexed: 11/24/2022]
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Tsuruta H, Yagishita T, Shimizu M, Tamura H. Megadose vitamin C suppresses sulfoconjugation in human colon carcinoma cell line Caco-2. Toxicol In Vitro 2010; 25:500-4. [PMID: 21144891 DOI: 10.1016/j.tiv.2010.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 11/12/2010] [Accepted: 12/01/2010] [Indexed: 01/14/2023]
Abstract
Intake of high doses of vitamin C has known to modulate sulfoconjugation of drugs in the intestine, but the underlying mechanisms for this effect remain to be elucidated. In the present study, we investigated the effects of vitamin C (l-ascorbic acid (AA)) on sulfation of 1-naphthol using Caco-2 cells, a model of human intestinal cells. We found that high dose of AA inhibited the accumulation of 1-naphthyl sulfate in Caco-2 culture medium within 24h in a dose-dependent manner (IC(50)=42 mM). Dehydroascorbic acid (DA), an oxidized form of AA, showed no inhibition. AA did not inhibit the in vitro sulfotransferase (SULT) activity toward 1-naphthol, whereas it reduced the expression of genes belonging to SULT1A family, SULT1A1 and SULT1A3. DA showed no effect on SULT1A gene expression. Consistent with the reduction in gene expression, AA reduced the cytosolic SULT activity towards 1-naphthol in the AA-treated Caco-2 cells. In addition, cAMP exerted an additive effect on AA-mediated repression of SULT1A gene expression. Our results suggest that megadose AA suppresses sulfoconjugation in the intestine mainly by downregulating the expression of SULT1A genes.
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Affiliation(s)
- Hidetaka Tsuruta
- Keio University, Faculty of Pharmacy, Shibakoen, Minatoku, Tokyo, Japan
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26
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Kim MK, Park KS, Lee C, Park HR, Choo H, Chong Y. Enhanced stability and intracellular accumulation of quercetin by protection of the chemically or metabolically susceptible hydroxyl groups with a pivaloxymethyl (POM) promoiety. J Med Chem 2010; 53:8597-607. [PMID: 21090565 DOI: 10.1021/jm101252m] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In order to increase stability of quercetin, its metabolically and chemically susceptible hydroxyl groups 7-OH and 3-OH respectively were transiently blocked with a pivaloxymethyl (POM) promoiety to provide two novel quercetin conjugates [7-O-POM-Q, 3-O-POM-Q]. In the absence of stabilizer (ascorbic acid), the synthesized conjugates showed significantly increased stability in cell culture media [t(½) = 4 h, 52 h] compared with quercetin (t(½) < 30 min) and quercetin prodrug 1 (t(½) = 0.8 h). In addition, the quercetin conjugate 2 underwent efficient cellular uptake and intracellular levels of its hydrolysis product, quercetin, were maintained up to 12 h. Stability and intracellular accumulation of were demonstrated by its stabilizer-independent cytostatic effect and induction of apoptotic cell death. Even though was more stable than, it failed to penetrate cell membranes. However, the remarkable stability of warrants further investigation of quercetin conjugates with various promoieties at the 3-OH position.
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Affiliation(s)
- Mi Kyoung Kim
- Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Korea
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Elevated cyclic AMP levels in T lymphocytes transformed by human T-cell lymphotropic virus type 1. J Virol 2010; 84:8732-42. [PMID: 20573814 DOI: 10.1128/jvi.00487-10] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Human T-cell lymphotropic virus type 1 (HTLV-1), the cause of adult T-cell leukemia/lymphoma (ATLL), transforms CD4(+) T cells to permanent growth through its transactivator Tax. HTLV-1-transformed cells share phenotypic properties with memory and regulatory T cells (T-reg). Murine T-reg-mediated suppression employs elevated cyclic AMP (cAMP) levels as a key regulator. This led us to determine cAMP levels in HTLV-1-transformed cells. We found elevated cAMP concentrations as a consistent feature of all HTLV-1-transformed cell lines, including in vitro-HTLV-1-transformed, Tax-transformed, and patient-derived cells. In transformed cells with conditional Tax expression, high cAMP levels coincided with the presence of Tax but were lost without it. However, transient ectopic expression of Tax alone was not sufficient to induce cAMP. We found specific downregulation of the cAMP-degrading phosphodiesterase 3B (PDE3B) in HTLV-1-transformed cells, which was independent of Tax in transient expression experiments. This is in line with the notion that PDE3B transcripts and cAMP levels are inversely correlated. Overexpression of PDE3B led to a decrease of cAMP in HTLV-1-transformed cells. Decreased expression of PDE3B was associated with inhibitory histone modifications at the PDE3B promoter and the PDE3B locus. In summary, Tax transformation and its continuous expression contribute to elevated cAMP levels, which may be regulated through PDE3B suppression. This shows that HTLV-1-transformed cells assume biological features of long-lived T-cell populations that potentially contribute to viral persistence.
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Gess B, Lohmann C, Halfter H, Young P. Sodium-dependent vitamin C transporter 2 (SVCT2) is necessary for the uptake of L-ascorbic acid into Schwann cells. Glia 2010; 58:287-99. [PMID: 19672970 DOI: 10.1002/glia.20923] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Ascorbic acid has been shown to be an essential component for in vitro myelination and to improve the clinical and pathological phenotype of a mouse model of Charcot-Marie-tooth disease 1A. The mechanism of ascorbic acid uptake into peripheral nerves, however, has not been addressed so far. Hence, we studied the expression and activity of sodium-dependent vitamin C transporters 1 and 2 (SVCT1 and 2) in the peripheral nervous system. Using immunohistochemistry, immunoblotting, and reverse transcription PCR, we could show that SVCT1 and 2 were differentially expressed in myelinated peripheral nerve fibers and Schwann cell (SC) cultures. SVCT1 was expressed at very low levels confined to the axons, whereas SVCT2 was highly expressed both in the axons and in the SCs. SVCT2 was localized particularly in SC compartments of uncompacted myelin. Uptake assays using (14)C-labeled ascorbic acid showed transport of ascorbic acid into SC cultures. Ascorbic acid transport was dependent on the concentration of sodium, magnesium, and calcium in the extracellular medium. Treatment with the flavonoid phloretin, a known inhibitor of SVCT1 and 2, and specific RNA interference with SVCT2 caused significant reductions in ascorbic acid uptake into SCs. Phloretin-inhibited uptake of ascorbic acid was further shown in freshly dissected, cell-culture-naïve rat sciatic nerves. These results provide evidence for the first time that uptake of ascorbic acid in the peripheral nervous system is crucially dependent on the expression and activity of SVCT2.
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Affiliation(s)
- Burkhard Gess
- Department of Neurology, University of Muenster, Albert-Schweitzer-Strasse 33, Muenster, Germany
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Han M, Pendem S, Teh SL, Sukumaran DK, Wu F, Wilson JX. Ascorbate protects endothelial barrier function during septic insult: Role of protein phosphatase type 2A. Free Radic Biol Med 2010; 48:128-35. [PMID: 19840845 PMCID: PMC2818310 DOI: 10.1016/j.freeradbiomed.2009.10.034] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 10/07/2009] [Accepted: 10/13/2009] [Indexed: 02/08/2023]
Abstract
Endothelial barrier dysfunction contributes to morbidity in sepsis. We tested the hypothesis that raising the intracellular ascorbate concentration protects the endothelial barrier from septic insult by inhibiting protein phosphatase type 2A. Monolayer cultures of microvascular endothelial cells were incubated with ascorbate, dehydroascorbic acid (DHAA), the NADPH oxidase inhibitors apocynin and diphenyliodonium, or the PP2A inhibitor okadaic acid and then were exposed to septic insult (lipopolysaccharide and interferon-gamma). Under standard culture conditions that depleted intracellular ascorbate, septic insult stimulated oxidant production and PP2A activity, dephosphorylated phosphoserine and phosphothreonine residues in the tight junction-associated protein occludin, decreased the abundance of occludin at cell borders, and increased monolayer permeability to albumin. NADPH oxidase inhibitors prevented PP2A activation and monolayer leak, showing that these changes required reactive oxygen species. Okadaic acid, at a concentration that inhibited PP2A activity and monolayer leak, prevented occludin dephosphorylation and redistribution, implicating PP2A in the response of occludin to septic insult. Incubation with ascorbate or DHAA raised intracellular ascorbate concentrations and mitigated the effects of septic insult. In conclusion, ascorbate acts within microvascular endothelial cells to inhibit septic stimulation of oxidant production by NADPH oxidase and thereby prevents PP2A activation, PP2A-dependent dephosphorylation and redistribution of occludin, and disruption of the endothelial barrier.
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Affiliation(s)
- Min Han
- Department of Exercise and Nutrition Sciences, University at Buffalo, 3435 Main Street, Buffalo, NY 14214-8028, USA
- Division of Nephrology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, P. R. China 430030
| | - Suresh Pendem
- Department of Exercise and Nutrition Sciences, University at Buffalo, 3435 Main Street, Buffalo, NY 14214-8028, USA
| | - Suet Ling Teh
- Department of Exercise and Nutrition Sciences, University at Buffalo, 3435 Main Street, Buffalo, NY 14214-8028, USA
| | | | - Feng Wu
- Department of Exercise and Nutrition Sciences, University at Buffalo, 3435 Main Street, Buffalo, NY 14214-8028, USA
| | - John X. Wilson
- Department of Exercise and Nutrition Sciences, University at Buffalo, 3435 Main Street, Buffalo, NY 14214-8028, USA
- Corresponding author. Telephone: +1 716 829 5596. Fax: +1 716 829 2428.
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Abstract
PURPOSE OF REVIEW We review recent advances in Charcot-Marie-Tooth disease (CMT), the most frequent inherited neuromuscular disorder. RECENT FINDINGS During the last year further progresses have occurred in this field and concerned identification of novel mutations in recently identified genes, allowing better definition of associated phenotypes; increased knowledge on pathophysiologic mechanisms of the different CMT types, with the contribution of cellular and animal model studies; studies on the natural history of CMT and attempts at developing appropriate outcome measures to assess disease course and intervention efficacy; trials with ascorbic acid in CMT type 1A; and studies on new possible therapeutic strategies. SUMMARY Such advances have implications on clinical management of CMT and are modifying the clinical approach to CMT, by improving diagnostic tools, allowing better definition of prognosis, and increasing the hope for future effective treatments. Research on CMT is important as is shedding light on important pathways that regulates the normal function of axonal transport, vesicular trafficking, and also revealing new aspects of intracellular organelles' function and interactions.
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Micallef J, Attarian S, Dubourg O, Gonnaud PM, Hogrel JY, Stojkovic T, Bernard R, Jouve E, Pitel S, Vacherot F, Remec JF, Jomir L, Azabou E, Al-Moussawi M, Lefebvre MN, Attolini L, Yaici S, Tanesse D, Fontes M, Pouget J, Blin O. Effect of ascorbic acid in patients with Charcot–Marie–Tooth disease type 1A: a multicentre, randomised, double-blind, placebo-controlled trial. Lancet Neurol 2009; 8:1103-10. [DOI: 10.1016/s1474-4422(09)70260-1] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Belin S, Kaya F, Duisit G, Giacometti S, Ciccolini J, Fontés M. Antiproliferative effect of ascorbic acid is associated with the inhibition of genes necessary to cell cycle progression. PLoS One 2009; 4:e4409. [PMID: 19197388 PMCID: PMC2634969 DOI: 10.1371/journal.pone.0004409] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Accepted: 12/05/2008] [Indexed: 11/18/2022] Open
Abstract
Background Ascorbic acid (AA), or Vitamin C, is most well known as a nutritional supplement with antioxidant properties. Recently, we demonstrated that high concentrations of AA act on PMP22 gene expression and partially correct the Charcot-Marie-Tooth disease phenotype in a mouse model. This is due to the capacity of AA, but not other antioxidants, to down-modulate cAMP intracellular concentration by a competitive inhibition of the adenylate cyclase enzymatic activity. Because of the critical role of cAMP in intracellular signalling, we decided to explore the possibility that ascorbic acid could modulate the expression of other genes. Methods and Findings Using human pangenomic microarrays, we found that AA inhibited the expression of two categories of genes necessary for cell cycle progression, tRNA synthetases and translation initiation factor subunits. In in vitro assays, we demonstrated that AA induced the S-phase arrest of proliferative normal and tumor cells. Highest concentrations of AA leaded to necrotic cell death. However, quiescent cells were not susceptible to AA toxicity, suggesting the blockage of protein synthesis was mainly detrimental in metabolically-active cells. Using animal models, we found that high concentrations of AA inhibited tumor progression in nude mice grafted with HT29 cells (derived from human colon carcinoma). Consistently, expression of tRNA synthetases and ieF2 appeared to be specifically decreased in tumors upon AA treatment. Conclusions AA has an antiproliferative activity, at elevated concentration that could be obtained using IV injection. This activity has been observed in vitro as well in vivo and likely results from the inhibition of expression of genes involved in protein synthesis. Implications for a clinical use in anticancer therapies will be discussed.
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Affiliation(s)
- Sophie Belin
- EA 4263, Therapy of Genetic Disorder, Faculté de Médecine de la Timone, Marseille, France
| | - Ferdinand Kaya
- EA 4263, Therapy of Genetic Disorder, Faculté de Médecine de la Timone, Marseille, France
| | - Ghislaine Duisit
- EA 4263, Therapy of Genetic Disorder, Faculté de Médecine de la Timone, Marseille, France
| | - Sarah Giacometti
- UPRES EA 3286, Laboratory of Pharmacokinetic and Toxicokinetic, Faculté de Pharmacie, Marseille, France
| | - Joseph Ciccolini
- UPRES EA 3286, Laboratory of Pharmacokinetic and Toxicokinetic, Faculté de Pharmacie, Marseille, France
| | - Michel Fontés
- EA 4263, Therapy of Genetic Disorder, Faculté de Médecine de la Timone, Marseille, France
- * E-mail:
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