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Caligiuri A, Becatti M, Porro N, Borghi S, Marra F, Pastore M, Taddei N, Fiorillo C, Gentilini A. Oxidative Stress and Redox-Dependent Pathways in Cholangiocarcinoma. Antioxidants (Basel) 2023; 13:28. [PMID: 38247453 PMCID: PMC10812651 DOI: 10.3390/antiox13010028] [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: 10/30/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024] Open
Abstract
Cholangiocarcinoma (CCA) is a primary liver tumor that accounts for 2% of all cancer-related deaths worldwide yearly. It can arise from cholangiocytes of biliary tracts, peribiliary glands, and possibly from progenitor cells or even hepatocytes. CCA is characterized by high chemoresistance, aggressiveness, and poor prognosis. Potentially curative surgical therapy is restricted to a small number of patients with early-stage disease (up to 35%). Accumulating evidence indicates that CCA is an oxidative stress-driven carcinoma resulting from chronic inflammation. Oxidative stress, due to enhanced reactive oxygen species (ROS) production and/or decreased antioxidants, has been recently suggested as a key factor in cholangiocyte oncogenesis through gene expression alterations and molecular damage. However, due to different experimental models and conditions, contradictory results regarding oxidative stress in cholangiocarcinoma have been reported. The role of ROS and antioxidants in cancer is controversial due to their context-dependent ability to stimulate tumorigenesis and support cancer cell proliferation or promote cell death. On these bases, the present narrative review is focused on illustrating the role of oxidative stress in cholangiocarcinoma and the main ROS-driven intracellular pathways. Heterogeneous data about antioxidant effects on cancer development are also discussed.
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Affiliation(s)
- Alessandra Caligiuri
- Department of Experimental and Clinical Medicine, University of Florence, 50139 Florence, Italy; (A.C.); (F.M.); (M.P.)
| | - Matteo Becatti
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, 50139 Florence, Italy; (M.B.); (N.P.); (S.B.); (N.T.)
| | - Nunzia Porro
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, 50139 Florence, Italy; (M.B.); (N.P.); (S.B.); (N.T.)
| | - Serena Borghi
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, 50139 Florence, Italy; (M.B.); (N.P.); (S.B.); (N.T.)
| | - Fabio Marra
- Department of Experimental and Clinical Medicine, University of Florence, 50139 Florence, Italy; (A.C.); (F.M.); (M.P.)
| | - Mirella Pastore
- Department of Experimental and Clinical Medicine, University of Florence, 50139 Florence, Italy; (A.C.); (F.M.); (M.P.)
| | - Niccolò Taddei
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, 50139 Florence, Italy; (M.B.); (N.P.); (S.B.); (N.T.)
| | - Claudia Fiorillo
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, 50139 Florence, Italy; (M.B.); (N.P.); (S.B.); (N.T.)
| | - Alessandra Gentilini
- Department of Experimental and Clinical Medicine, University of Florence, 50139 Florence, Italy; (A.C.); (F.M.); (M.P.)
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2
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Miyazaki T, Kanatsu-Shinohara M, Ogonuki N, Matoba S, Ogura A, Yabe-Nishimura C, Zhang H, Pommier Y, Trumpp A, Shinohara T. Glutamine protects mouse spermatogonial stem cells against NOX1-derived ROS for sustaining self-renewal division in vitro. Development 2023; 150:dev201157. [PMID: 36897562 PMCID: PMC10698750 DOI: 10.1242/dev.201157] [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: 07/24/2022] [Accepted: 02/24/2023] [Indexed: 03/11/2023]
Abstract
Reactive oxygen species (ROS) are generated from NADPH oxidases and mitochondria; they are generally harmful for stem cells. Spermatogonial stem cells (SSCs) are unique among tissue-stem cells because they undergo ROS-dependent self-renewal via NOX1 activation. However, the mechanism by which SSCs are protected from ROS remains unknown. Here, we demonstrate a crucial role for Gln in ROS protection using cultured SSCs derived from immature testes. Measurements of amino acids required for SSC cultures revealed the indispensable role of Gln in SSC survival. Gln induced Myc expression to drive SSC self-renewal in vitro, whereas Gln deprivation triggered Trp53-dependent apoptosis and impaired SSC activity. However, apoptosis was attenuated in cultured SSCs that lacked NOX1. In contrast, cultured SSCs lacking Top1mt mitochondria-specific topoisomerase exhibited poor mitochondrial ROS production and underwent apoptosis. Gln deprivation reduced glutathione production; supra-molar Asn supplementation allowed offspring production from SSCs cultured without Gln. Therefore, Gln ensures ROS-dependent SSC-self-renewal by providing protection against NOX1 and inducing Myc.
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Affiliation(s)
- Takehiro Miyazaki
- Department of Molecular Genetics, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Mito Kanatsu-Shinohara
- Department of Molecular Genetics, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Narumi Ogonuki
- RIKEN, Bioresource Research Center, Tsukuba 305-0074, Japan
| | - Shogo Matoba
- RIKEN, Bioresource Research Center, Tsukuba 305-0074, Japan
| | - Atsuo Ogura
- RIKEN, Bioresource Research Center, Tsukuba 305-0074, Japan
| | - Chihiro Yabe-Nishimura
- Deparment of Pharmacology, Kyoto Prefectural University of Medicine, Kyoto 606-8566, Japan
| | - Hongliang Zhang
- Deveopmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institute of Health, Bethesda, MD 20892, USA
| | - Yves Pommier
- Deveopmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institute of Health, Bethesda, MD 20892, USA
| | - Andreas Trumpp
- Division of Stem Cells and Cancer, Deutsches Krebsforshungszentrum (DKFZ), 69120 Heidelberg, Germany
| | - Takashi Shinohara
- Department of Molecular Genetics, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
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3
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Defendi-Cho G, Gould TM. In vitro culture of bovine fibroblasts using select serum-free media supplemented with Chlorella vulgaris extract. BMC Biotechnol 2023; 23:4. [PMID: 36755248 PMCID: PMC9909908 DOI: 10.1186/s12896-023-00774-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 01/30/2023] [Indexed: 02/10/2023] Open
Abstract
Standard cell culture practices require the addition of animal-derived serum to culture media to achieve adequate cell growth. Typically, 5-10% by volume of fetal bovine serum (FBS) is used, which accounts for a vast majority of the media cost while also imposing environmental and ethical concerns associated with the use of animal serum. Here we tested the efficacy of culturing cells by replacing serum in the media with algae extract and select additives. Using LC-MS, we compared molecular signatures of FBS to Chlorella algae extracts and identified NAD(H)/NADP(H) as common and relatively abundant features in their characteristic profiles. Bovine fibroblasts, cultured in serum-free media supplemented with C. vulgaris extract and just two growth factors plus insulin, showed significant growth with enhanced viability compared to control cells cultured without serum, albeit still lower than that of controls cultured with 10% FBS. Moreover, C. vulgaris extract enhanced cell viability beyond that of cells cultured with the two growth factors and insulin alone. These results suggest that key components in serum which are essential for cell growth may also be present in C. vulgaris extract, demonstrating that it may be used at least as a partial alternative to serum for cell culture applications.
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Affiliation(s)
- Galileo Defendi-Cho
- grid.254544.60000 0001 0657 7781Department of Chemistry and Biochemistry, Colorado College, Colorado Springs, CO USA
| | - Timothy M. Gould
- grid.254544.60000 0001 0657 7781Department of Chemistry and Biochemistry, Colorado College, Colorado Springs, CO USA
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4
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Hang TD, Hung HM, Beckers P, Desmet N, Lamrani M, Massie A, Hermans E, Vanommeslaeghe K. Structural investigation of human cystine/glutamate antiporter system xc− (Sxc−) using homology modeling and molecular dynamics. Front Mol Biosci 2022; 9:1064199. [DOI: 10.3389/fmolb.2022.1064199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/15/2022] [Indexed: 12/04/2022] Open
Abstract
The cystine/glutamate antiporter system xc− (Sxc−) belongs to the SLC7 family of plasma membrane transporters. It exports intracellular glutamate along the latter’s concentration gradient as a driving force for cellular uptake of cystine. Once imported, cystine is mainly used for the production of glutathione, a tripeptide thiol crucial in maintenance of redox homeostasis and protection of cells against oxidative stress. Overexpression of Sxc− has been found in several cancer cells, where it is thought to counteract the increased oxidative stress. In addition, Sxc− is important in the central nervous system, playing a complex role in regulating glutamatergic neurotransmission and glutamate toxicity. Accordingly, this transporter is considered a potential target for the treatment of cancer as well as neurodegenerative diseases. Till now, no specific inhibitors are available. We herein present four conformations of Sxc− along its transport pathway, obtained using multi-template homology modeling and refined by means of Molecular Dynamics. Comparison with a very recently released cryo-EM structure revealed an excellent agreement with our inward-open conformation. Intriguingly, our models contain a structured N-terminal domain that is unresolved in the experimental structures and is thought to play a gating role in the transport mechanism of other SLC7 family members. In contrast to the inward-open model, there is no direct experimental counterpart for the other three conformations we obtained, although they are in fair agreement with the other stages of the transport mechanism seen in other SLC7 transporters. Therefore, our models open the prospect for targeting alternative Sxc− conformations in structure-based drug design efforts.
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5
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4-Methylumebelliferone Enhances Radiosensitizing Effects of Radioresistant Oral Squamous Cell Carcinoma Cells via Hyaluronan Synthase 3 Suppression. Cells 2022; 11:cells11233780. [PMID: 36497040 PMCID: PMC9741296 DOI: 10.3390/cells11233780] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/20/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
Radioresistant (RR) cells are poor prognostic factors for tumor recurrence and metastasis after radiotherapy. The hyaluronan (HA) synthesis inhibitor, 4-methylumbelliferone (4-MU), shows anti-tumor and anti-metastatic effects through suppressing HA synthase (HAS) expression in various cancer cells. We previously reported that the administration of 4-MU with X-ray irradiation enhanced radiosensitization. However, an effective sensitizer for radioresistant (RR) cells is yet to be established, and it is unknown whether 4-MU exerts radiosensitizing effects on RR cells. We investigated the radiosensitizing effects of 4-MU in RR cell models. This study revealed that 4-MU enhanced intracellular oxidative stress and suppressed the expression of cluster-of-differentiation (CD)-44 and cancer stem cell (CSC)-like phenotypes. Interestingly, eliminating extracellular HA using HA-degrading enzymes did not cause radiosensitization, whereas HAS3 knockdown using siRNA showed similar effects as 4-MU treatment. These results suggest that 4-MU treatment enhances radiosensitization of RR cells through enhancing oxidative stress and suppressing the CSC-like phenotype. Furthermore, the radiosensitizing mechanisms of 4-MU may involve HAS3 or intracellular HA synthesized by HAS3.
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6
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Managing GSH elevation and hypoxia to overcome resistance of cancer therapies using functionalized nanocarriers. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2021.103022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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7
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Ribeiro da Silva M, Zaborowska I, Carillo S, Bones J. A rapid, simple and sensitive microfluidic chip electrophoresis mass spectrometry method for monitoring amino acids in cell culture media. J Chromatogr A 2021; 1651:462336. [PMID: 34153732 DOI: 10.1016/j.chroma.2021.462336] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 06/01/2021] [Accepted: 06/04/2021] [Indexed: 10/21/2022]
Abstract
The development and optimization of cell culture media for biotech applications is a fundamental step of process development. The composition of cell culture media requires an ideal blend of amino acids, vitamins, nucleosides, lipids, carbohydrates, trace elements and other components. The ability to monitor these constituents is required to ensure that cells receive sufficient nutrients to facilitate growth, viability and productivity. Analysis of cell culture media is challenging due to the range and diversity of compounds contained in this matrix and normally requires time consuming methods. A rapid, simple and sensitive microfluidic chip CE-MS method is described to monitor amino acids in chemically defined cell culture media from a Chinese hamster ovary cell line cultured over a period of 10 days. The described platform enabled the separation of 16 amino acids in less than 2 minutes and without the requirement for extensive sample preparation. The analytical parameters evaluated were precision, linearity, limit of detection and limit of quantification. The majority of essential amino acids were present in cell culture growth in high concentrations compared to non-essential amino acids. Over the course of the 10 days cell culture the concentration of certain amino acids declined by up to 100%. Microfluidic chip based CE-MS methods can be used effectively to obtain the consumption rates of amino acids in cell culture media during cell growth and to perform at-line monitoring and screening of cell culture status.
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Affiliation(s)
| | - Izabela Zaborowska
- NIBRT - National Institute for Bioprocessing Research and Training, Dublin, Ireland
| | - Sara Carillo
- NIBRT - National Institute for Bioprocessing Research and Training, Dublin, Ireland
| | - Jonathan Bones
- NIBRT - National Institute for Bioprocessing Research and Training, Dublin, Ireland; School of Chemical and Bioprocess Engineering, University College Dublin, Dublin 4, Ireland.
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8
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Thanee M, Dokduang H, Kittirat Y, Phetcharaburanin J, Klanrit P, Titapun A, Namwat N, Khuntikeo N, Wangwiwatsin A, Saya H, Loilome W. CD44 modulates metabolic pathways and altered ROS-mediated Akt signal promoting cholangiocarcinoma progression. PLoS One 2021; 16:e0245871. [PMID: 33780455 PMCID: PMC8007026 DOI: 10.1371/journal.pone.0245871] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 01/10/2021] [Indexed: 12/12/2022] Open
Abstract
CD44 is a transmembrane glycoprotein, the phosphorylation of which can directly trigger intracellular signaling, particularly Akt protein, for supporting cell growth, motility and invasion. This study examined the role of CD44 on the progression of Cholangiocarcinoma (CCA) using metabolic profiling to investigate the molecular mechanisms involved in the Akt signaling pathway. Our results show that the silencing of CD44 decreases Akt and mTOR phosphorylation resulting in p21 and Bax accumulation and Bcl-2 suppression that reduces cell proliferation. Moreover, an inhibition of cell migration and invasion regulated by CD44. Similarly, the silencing of CD44 showed an alteration in the epithelial-mesenchymal transition (EMT), e.g. an upregulation of E-cadherin and a downregulation of vimentin, and the reduction of the matrix metalloproteinase (MMP)-9 signal. Interestingly, a depletion of CD44 leads to metabolic pathway changes resulting in redox status modification and Trolox (anti-oxidant) led to the recovery of the cancer cell functions. Based on our findings, the regulation of CCA progression and metastasis via the redox status-related Akt signaling pathway depends on the alteration of metabolic profiling synchronized by CD44.
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Affiliation(s)
- Malinee Thanee
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand
- Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Hasaya Dokduang
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand
| | - Yingpinyapat Kittirat
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Jutarop Phetcharaburanin
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Poramate Klanrit
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Attapol Titapun
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand
- Department of Surgery, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Nisana Namwat
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Narong Khuntikeo
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand
- Department of Surgery, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Arporn Wangwiwatsin
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Hideyuki Saya
- Division of Gene Regulation, Institute for Advanced Medical Research (IAMR), Keio University School of Medicine, Tokyo, Japan
| | - Watcharin Loilome
- Cholangiocarcinoma Screening and Care Program (CASCAP), Khon Kaen University, Khon Kaen, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen, Thailand
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- * E-mail:
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9
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Ueda S, Takanashi M, Sudo K, Kanekura K, Kuroda M. miR-27a ameliorates chemoresistance of breast cancer cells by disruption of reactive oxygen species homeostasis and impairment of autophagy. J Transl Med 2020; 100:863-873. [PMID: 32066826 DOI: 10.1038/s41374-020-0409-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 01/28/2020] [Indexed: 12/16/2022] Open
Abstract
In patients with breast cancer, primary chemotherapy often fails due to survival of chemoresistant breast cancer stem cells (BCSCs) which results in recurrence and metastasis of the tumor. However, the factors determining the chemoresistance of BCSCs have remained to be investigated. Here, we profiled a series of differentially expressed microRNAs (miRNAs) between parental adherent breast cancer cells and BCSC-mimicking mammosphere-derived cancer cells, and identified hsa-miR-27a as a negative regulator for survival and chemoresistance of BCSCs. In the mammosphere, we found that the expression of hsa-miR-27a was downregulated, and ectopic overexpression of hsa-miR-27a reduced both number and size of mammospheres. In addition, overexpression of hsa-miR-27a sensitized breast cancer cells to anticancer drugs by downregulation of genes essential for detoxification of reactive oxygen species (ROS) and impairment of autophagy. Therefore, enhancing the hsa-miR-27a signaling pathway can be a potential therapeutic modality for breast cancer.
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Affiliation(s)
- Shinobu Ueda
- Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan
| | - Masakatsu Takanashi
- Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan
| | - Katsuko Sudo
- Preclinical Research Center, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan
| | - Kohsuke Kanekura
- Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan
| | - Masahiko Kuroda
- Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan.
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10
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Chase LA, VerHeulen Kleyn M, Schiller N, King AG, Flores G, Engelsman SB, Bowles C, Smith SL, Robinson AE, Rothstein J. Hydrogen peroxide triggers an increase in cell surface expression of system x c- in cultured human glioma cells. Neurochem Int 2019; 134:104648. [PMID: 31874187 DOI: 10.1016/j.neuint.2019.104648] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/15/2019] [Accepted: 12/18/2019] [Indexed: 12/14/2022]
Abstract
System xc- exchanges extracellular cystine for intracellular glutamate across the plasma membrane of many cell types. One of the physiological roles of System xc- is to provide cystine for synthesis of the antioxidant glutathione. Here we report that hydrogen peroxide (H2O2) triggers the translocation of System xc- to the plasma membrane within 10 min of the initial exposure. Specifically, we observed a three-fold increase in 35S-l-cystine uptake following a 10 min exposure to 0.3 mM H2O2. This effect was dose-dependent with an EC50 for H2O2 of 65 μM. We then used cell surface biotinylation analysis to test the hypothesis that the increase in activity is due to an increased number of transporters on the plasma membrane. We demonstrated that the amount of transporter protein, xCT, localized to the plasma membrane doubles within 10 min of H2O2 exposure as a result of an increase in its delivery rate and a reduction in its internalization rate. In addition, we demonstrated that H2O2 triggered a rapid decrease in total cellular glutathione which recovered within 2 h of the oxidative insult. The kinetics of glutathione recovery matched the time course for the recovery of xCT cell surface expression and System xc- activity following removal of the oxidative insult. Collectively, these results suggest that oxidants acutely modulate the activity of System xc- by increasing its cell surface expression, and that this process may serve as an important mechanism to increase de novo glutathione synthesis during periods of oxidative stress.
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Affiliation(s)
- Leah A Chase
- Department of Chemistry, Hope College, Holland, MI, 49423, USA; Department of Biology, Hope College, Holland, MI, 49423, USA.
| | | | - NaTasha Schiller
- Department of Chemistry, Hope College, Holland, MI, 49423, USA; Department of Biology, Hope College, Holland, MI, 49423, USA
| | - Abby Goltz King
- Department of Chemistry, Hope College, Holland, MI, 49423, USA
| | - Guillermo Flores
- Department of Chemistry, Hope College, Holland, MI, 49423, USA; Department of Biology, Hope College, Holland, MI, 49423, USA
| | | | | | - Sara Lang Smith
- Department of Biology, Hope College, Holland, MI, 49423, USA
| | - Anne E Robinson
- Department of Chemistry, Hope College, Holland, MI, 49423, USA; Department of Biology, Hope College, Holland, MI, 49423, USA
| | - Jeffrey Rothstein
- Department of Neurology, Department of Neuroscience, Johns Hopkins University, Baltimore, MD, 21287, USA
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11
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Ishii T, Warabi E. Mechanism of Rapid Nuclear Factor-E2-Related Factor 2 (Nrf2) Activation via Membrane-Associated Estrogen Receptors: Roles of NADPH Oxidase 1, Neutral Sphingomyelinase 2 and Epidermal Growth Factor Receptor (EGFR). Antioxidants (Basel) 2019; 8:antiox8030069. [PMID: 30889865 PMCID: PMC6466580 DOI: 10.3390/antiox8030069] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 03/07/2019] [Accepted: 03/13/2019] [Indexed: 12/12/2022] Open
Abstract
Membrane-associated estrogen receptors (ER)-α36 and G protein-coupled estrogen receptor (GPER) play important roles in the estrogen’s rapid non-genomic actions including stimulation of cell proliferation. Estrogen via these receptors induces rapid activation of transcription factor nuclear factor-E2-related factor 2 (Nrf2), a master regulator of detoxification and antioxidant systems, playing a key role in the metabolic reprogramming to support cell proliferation. This review highlights the possible mechanism underlying rapid Nrf2 activation via membrane-associated estrogen receptors by estrogen and phytoestrogens. Stimulation of ER-α36-GPER signaling complex rapidly induces Src-mediated transactivation of epidermal growth factor receptor (EGFR) leading to a kinase-mediated signaling cascade. We propose a novel hypothesis that ER-α36-GPER signaling initially induces rapid and temporal activation of NADPH oxidase 1 to generate superoxide, which subsequently activates redox-sensitive neutral sphingomyelinase 2 generating the lipid signaling mediator ceramide. Generation of ceramide is required for Ras activation and ceramide-protein kinase C ζ-casein kinase 2 (CK2) signaling. Notably, CK2 enhances chaperone activity of the Cdc37-Hsp90 complex supporting activation of various signaling kinases including Src, Raf and Akt (protein kinase B). Activation of Nrf2 may be induced by cooperation of two signaling pathways, (i) Nrf2 stabilization by direct phosphorylation by CK2 and (ii) EGFR-Ras-PI 3 kinase (PI3K)-Akt axis which inhibits glycogen synthase kinase 3β leading to enhanced nuclear transport and stability of Nrf2.
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Affiliation(s)
- Tetsuro Ishii
- Faculty of Medicine, University of Tsukuba, Tsukuba Ibaraki 305-8575, Japan.
| | - Eiji Warabi
- Faculty of Medicine, University of Tsukuba, Tsukuba Ibaraki 305-8575, Japan.
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12
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Yip Y, Yan Z, Law G, Wong W. Reaction‐Based Europium Complex for Specific Detection of Cysteine Over Homocysteine and Glutathione with Variable‐Temperature Kinetic Studies. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201801315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yuk‐Wang Yip
- The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen PR China
- State Key Laboratory of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hung Hom Hong Kong SAR
| | - Zhiyuan Yan
- State Key Laboratory of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hung Hom Hong Kong SAR
| | - Ga‐Lai Law
- The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen PR China
- State Key Laboratory of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hung Hom Hong Kong SAR
| | - Wing‐Tak Wong
- The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen PR China
- State Key Laboratory of Chemical Biology and Drug Discovery Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University Hung Hom Hong Kong SAR
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13
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Ortega-Ferrusola C, Martin Muñoz P, Ortiz-Rodriguez JM, Anel-López L, Balao da Silva C, Álvarez M, de Paz P, Tapia JA, Anel L, Silva- Rodríguez A, Aitken RJ, Gil MC, Gibb Z, Peña FJ. Depletion of thiols leads to redox deregulation, production of 4-hydroxinonenal and sperm senescence: a possible role for GSH regulation in spermatozoa†. Biol Reprod 2018; 100:1090-1107. [DOI: 10.1093/biolre/ioy241] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/06/2018] [Accepted: 11/07/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
| | - Patricia Martin Muñoz
- Laboratory of Equine Reproduction and Equine Spermatology, Veterinary Teaching Hospital, University of Extremadura, Cáceres, Spain
| | - Jose Manuel Ortiz-Rodriguez
- Laboratory of Equine Reproduction and Equine Spermatology, Veterinary Teaching Hospital, University of Extremadura, Cáceres, Spain
| | - Luis Anel-López
- Reproduction and Obstetrics Department of Animal Medicine and Surgery, University of León, Spain
| | | | - Mercedes Álvarez
- Reproduction and Obstetrics Department of Animal Medicine and Surgery, University of León, Spain
| | - Paulino de Paz
- Reproduction and Obstetrics Department of Animal Medicine and Surgery, University of León, Spain
| | - Jose Antonio Tapia
- Laboratory of Equine Reproduction and Equine Spermatology, Veterinary Teaching Hospital, University of Extremadura, Cáceres, Spain
| | - Luis Anel
- Reproduction and Obstetrics Department of Animal Medicine and Surgery, University of León, Spain
| | - Antonio Silva- Rodríguez
- Facility of Innovation and Analysis in Animal Source Foodstuffs, University of Extremadura, Cáceres, Spain
| | - Robert J Aitken
- Facility of Innovation and Analysis in Animal Source Foodstuffs, University of Extremadura, Cáceres, Spain
| | - M Cruz Gil
- Laboratory of Equine Reproduction and Equine Spermatology, Veterinary Teaching Hospital, University of Extremadura, Cáceres, Spain
| | - Zamira Gibb
- Priority Research Center in Reproductive Science, School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
| | - Fernando J Peña
- Laboratory of Equine Reproduction and Equine Spermatology, Veterinary Teaching Hospital, University of Extremadura, Cáceres, Spain
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14
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Zheng Y, Ritzenthaler JD, Burke TJ, Otero J, Roman J, Watson WH. Age-dependent oxidation of extracellular cysteine/cystine redox state (E h(Cys/CySS)) in mouse lung fibroblasts is mediated by a decline in Slc7a11 expression. Free Radic Biol Med 2018; 118:13-22. [PMID: 29458149 PMCID: PMC5884717 DOI: 10.1016/j.freeradbiomed.2018.02.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 01/23/2018] [Accepted: 02/15/2018] [Indexed: 12/26/2022]
Abstract
Aging is associated with progressive oxidation of the extracellular environment. The redox state of human plasma, defined by the concentrations of cysteine (Cys) and cystine (CySS), becomes more oxidized as we age. Recently, we showed that fibroblasts isolated from the lungs of young and old mice retain this differential phenotype; old cells produce and maintain a more oxidizing extracellular redox potential (Eh(Cys/CySS)) than young cells. Microarray analysis identified down-regulation of Slc7a11, the light subunit of the CySS/glutamate transporter, as a potential mediator of age-related oxidation in these cells. The purpose of the present study was to investigate the mechanistic link between Slc7a11 expression and extracellular Eh(Cys/CySS). Sulforaphane treatment or overexpression of Slc7a11 was used to increase Slc7a11 in lung fibroblasts from old mice, and sulfasalazine treatment or siRNA-mediated knock down was used to decrease Slc7a11 in young fibroblasts. Slc7a11 mRNA levels were measured by real-time PCR, Slc7a11 activity was determined by measuring the rate of glutamate release, Cys, CySS, glutathione (GSH) and its disulfide (GSSG) were measured by HPLC, and Eh(Cys/CySS) was calculated from the Nernst equation. The results showed that both Eh(Cys/CySS) and Eh(GSH/GSSG) were more oxidized in the conditioned media of old cells than in young cells. Up-regulation of Slc7a11 via overexpression or sulforaphane treatment restored extracellular Eh(Cys/CySS) in cultures of old cells, whereas down-regulation reproduced the oxidizing Eh(Cys/CySS) in young cells. Only sulforaphane treatment was able to increase total GSH and restore Eh(GSH/GSSG), whereas overexpression, knock down and sulfasalazine had no effect on these parameters. In addition, inhibition of GSH synthesis with buthionine sulfoximine had no effect on the ability of cells to restore their extracellular redox potential in response to an oxidative challenge. In conclusion, our study reveals Slc7a11 is the key regulator of age-dependent changes in extracellular Eh(Cys/CySS) in primary mouse lung fibroblasts, and its effects are not dependent on GSH synthesis.
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Affiliation(s)
- Yuxuan Zheng
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, 505 South Hancock Street, Louisville, KY 40202, United States.
| | - Jeffrey D Ritzenthaler
- Department of Medicine, Divisions of Gastroenterology, Hepatology and Nutrition, and Pulmonary, Critical Care, & Sleep Medicine, University of Louisville School of Medicine, 550 South Jackson Street, Louisville, KY 40202, United States.
| | - Tom J Burke
- Department of Medicine, Divisions of Gastroenterology, Hepatology and Nutrition, and Pulmonary, Critical Care, & Sleep Medicine, University of Louisville School of Medicine, 550 South Jackson Street, Louisville, KY 40202, United States.
| | - Javier Otero
- Department of Medicine, Divisions of Gastroenterology, Hepatology and Nutrition, and Pulmonary, Critical Care, & Sleep Medicine, University of Louisville School of Medicine, 550 South Jackson Street, Louisville, KY 40202, United States.
| | - Jesse Roman
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, 505 South Hancock Street, Louisville, KY 40202, United States; Department of Medicine, Divisions of Gastroenterology, Hepatology and Nutrition, and Pulmonary, Critical Care, & Sleep Medicine, University of Louisville School of Medicine, 550 South Jackson Street, Louisville, KY 40202, United States; Robley Rex Veterans Affairs Medical Center, 800 Zorn Avenue, Louisville, KY 40206, United States.
| | - Walter H Watson
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, 505 South Hancock Street, Louisville, KY 40202, United States; Department of Medicine, Divisions of Gastroenterology, Hepatology and Nutrition, and Pulmonary, Critical Care, & Sleep Medicine, University of Louisville School of Medicine, 550 South Jackson Street, Louisville, KY 40202, United States.
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15
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Fazzari J, Linher-Melville K, Singh G. Tumour-Derived Glutamate: Linking Aberrant Cancer Cell Metabolism to Peripheral Sensory Pain Pathways. Curr Neuropharmacol 2018; 15:620-636. [PMID: 27157265 PMCID: PMC5543678 DOI: 10.2174/1570159x14666160509123042] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/16/2016] [Accepted: 04/17/2016] [Indexed: 01/22/2023] Open
Abstract
Background Chronic pain is a major symptom that develops in cancer patients, most commonly emerging during advanced stages of the disease. The nature of cancer-induced pain is complex, and the efficacy of current therapeutic interventions is restricted by the dose-limiting side-effects that accompany common centrally targeted analgesics. Methods This review focuses on how up-regulated glutamate production and export by the tumour converge at peripheral afferent nerve terminals to transmit nociceptive signals through the transient receptor cation channel, TRPV1, thereby initiating central sensitization in response to peripheral disease-mediated stimuli. Results Cancer cells undergo numerous metabolic changes that include increased glutamine catabolism and over-expression of enzymes involved in glutaminolysis, including glutaminase. This mitochondrial enzyme mediates glutaminolysis, producing large pools of intracellular glutamate. Up-regulation of the plasma membrane cystine/glutamate antiporter, system xc-, promotes aberrant glutamate release from cancer cells. Increased levels of extracellular glutamate have been associated with the progression of cancer-induced pain and we discuss how this can be mediated by activation of TRPV1. Conclusion With a growing population of patients receiving inadequate treatment for intractable pain, new targets need to be considered to better address this largely unmet clinical need for improving their quality of life. A better understanding of the mechanisms that underlie the unique qualities of cancer pain will help to identify novel targets that are able to limit the initiation of pain from a peripheral source–the tumour.
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Affiliation(s)
| | | | - Gurmit Singh
- Department of Pathology and Molecular Medicine; Michael G. DeGroote Institute for Pain Research and Care, McMaster University, Hamilton, ON. Canada
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16
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Stennett BA, Frankowski JC, Peris J, Knackstedt LA. Ceftriaxone reduces alcohol intake in outbred rats while upregulating xCT in the nucleus accumbens core. Pharmacol Biochem Behav 2017; 159:18-23. [PMID: 28687200 DOI: 10.1016/j.pbb.2017.07.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 06/19/2017] [Accepted: 07/03/2017] [Indexed: 12/11/2022]
Abstract
Alcohol addiction is a chronic disease characterized by an inability to regulate drinking. A critical brain region involved in alcohol consumption is the nucleus accumbens (NA). Glutamate transmission in this region regulates alcohol consumption and relapse to alcohol-seeking. Across multiple alcohol-administration rodent models, basal extracellular glutamate levels are increased in the NA during early withdrawal. Glutamate transporter 1 (GLT-1) and system xC-, containing the subunit xCT, regulate NA glutamate levels. Ceftriaxone (Cef) increases expression and function of both transporters following extinction from cocaine self-administration and here we sought to determine if Cef would similarly decrease alcohol consumption while increasing xCT and GLT-1 in the NA core. We used the intermittent access to alcohol (IAA) paradigm to induce drinking in outbred Sprague-Dawley rats; this paradigm permits rats access to alcohol (20%v/v) for 24-h without water deprivation, followed by 24-h of abstinence. Following 17 24-h drinking sessions, Cef treatment (200mg/kg IP) was initiated and continued for 5days while a control group received vehicle (0.9% saline IP). Alcohol consumption was assessed for two 24-h periods during Cef and two 24-h periods after cessation of Cef treatment. In a separate cohort of rats, Cef's ability to alter blood alcohol levels (BALs) after a non-contingent alcohol injection (1g/kg) was assessed. We found that Cef decreased alcohol consumption during the period of Cef treatment and on the two days following injections, and this was accompanied by an increase in NA core xCT expression. Furthermore, a history of alcohol consumption did not alter xCT and GLT-1 expression relative to alcohol-naïve controls. Cef did not alter BALs, indicating that the reduction in alcohol consumption was not caused by altered alcohol clearance. These results indicate that while Cef reduces alcohol consumption in outbred rats, its ability to do so is not associated with an increase in GLT-1 expression.
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Affiliation(s)
- Bethany A Stennett
- Psychology Department, University of Florida, Gainesville, FL, United States.
| | - Jan C Frankowski
- Psychology Department, University of Florida, Gainesville, FL, United States
| | - Joanna Peris
- Department of Pharmacodynamics, University of Florida, Gainesville, FL, United States
| | - Lori A Knackstedt
- Psychology Department, University of Florida, Gainesville, FL, United States
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17
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Hammad AM, Althobaiti YS, Das SC, Sari Y. Effects of repeated cocaine exposure and withdrawal on voluntary ethanol drinking, and the expression of glial glutamate transporters in mesocorticolimbic system of P rats. Mol Cell Neurosci 2017; 82:58-65. [PMID: 28442364 DOI: 10.1016/j.mcn.2017.04.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/18/2017] [Accepted: 04/20/2017] [Indexed: 11/26/2022] Open
Abstract
Glutamatergic neurotransmission within the brain's reward circuits plays a major role in the reinforcing properties of both ethanol and cocaine. Glutamate homeostasis is regulated by several glutamate transporters, including glutamate transporter type 1 (GLT-1), cystine/glutamate transporter (xCT), and glutamate aspartate transporter (GLAST). Cocaine exposure has been shown to induce a dysregulation in glutamate homeostasis and a decrease in the expression of GLT-1 and xCT in the nucleus accumbens (NAc). In this study, alcohol preferring (P) rats were exposed to free-choice of ethanol (15% and 30%) and/or water for five weeks. On Week 6, rats were administered (i.p.) cocaine (10 and 20mg/kg) or saline for 12 consecutive days. This study tested two groups of rats: the first group was euthanized after seven days of repeated cocaine i.p. injection, and the second group was deprived from cocaine for five days and euthanized at Day 5 after cocaine withdrawal. Only repeated cocaine (20mg/kg, i.p.) exposure decreased ethanol intake from Day 3 through Day 8. Co-exposure of cocaine and ethanol decreased the relative mRNA expression and the expression of GLT-1 in the NAc but not in the medial prefrontal cortex (mPFC). Importantly, co-exposure of cocaine and ethanol decreased relative expression of xCT in the NAc but not in the mPFC. Our findings demonstrated that chronic cocaine exposure affects ethanol intake; and ethanol and cocaine co-abuse alters the expression of glial glutamate transporters.
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Affiliation(s)
- Alaa M Hammad
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH, USA
| | - Yusuf S Althobaiti
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH, USA
| | - Sujan C Das
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH, USA
| | - Youssef Sari
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH, USA.
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18
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Doll S, Proneth B, Tyurina YY, Panzilius E, Kobayashi S, Ingold I, Irmler M, Beckers J, Aichler M, Walch A, Prokisch H, Trümbach D, Mao G, Qu F, Bayir H, Füllekrug J, Scheel CH, Wurst W, Schick JA, Kagan VE, Angeli JPF, Conrad M. ACSL4 dictates ferroptosis sensitivity by shaping cellular lipid composition. Nat Chem Biol 2016; 13:91-98. [PMID: 27842070 DOI: 10.1038/nchembio.2239] [Citation(s) in RCA: 2125] [Impact Index Per Article: 265.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 09/13/2016] [Indexed: 02/07/2023]
Abstract
Ferroptosis is a form of regulated necrotic cell death controlled by glutathione peroxidase 4 (GPX4). At present, mechanisms that could predict sensitivity and/or resistance and that may be exploited to modulate ferroptosis are needed. We applied two independent approaches-a genome-wide CRISPR-based genetic screen and microarray analysis of ferroptosis-resistant cell lines-to uncover acyl-CoA synthetase long-chain family member 4 (ACSL4) as an essential component for ferroptosis execution. Specifically, Gpx4-Acsl4 double-knockout cells showed marked resistance to ferroptosis. Mechanistically, ACSL4 enriched cellular membranes with long polyunsaturated ω6 fatty acids. Moreover, ACSL4 was preferentially expressed in a panel of basal-like breast cancer cell lines and predicted their sensitivity to ferroptosis. Pharmacological targeting of ACSL4 with thiazolidinediones, a class of antidiabetic compound, ameliorated tissue demise in a mouse model of ferroptosis, suggesting that ACSL4 inhibition is a viable therapeutic approach to preventing ferroptosis-related diseases.
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Affiliation(s)
- Sebastian Doll
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Bettina Proneth
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Yulia Y Tyurina
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Elena Panzilius
- Institute of Stem Cell Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Sho Kobayashi
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Irina Ingold
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Martin Irmler
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Johannes Beckers
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Michaela Aichler
- Institute of Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Axel Walch
- Institute of Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Holger Prokisch
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,Technische Universität München, Institute of Human Genetics, München, Germany
| | - Dietrich Trümbach
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Gaowei Mao
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Feng Qu
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Hulya Bayir
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Joachim Füllekrug
- Department of Gastroenterology, University of Heidelberg, Heidelberg, Germany
| | - Christina H Scheel
- Institute of Stem Cell Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Joel A Schick
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Valerian E Kagan
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | | - Marcus Conrad
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
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19
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Thanee M, Loilome W, Techasen A, Sugihara E, Okazaki S, Abe S, Ueda S, Masuko T, Namwat N, Khuntikeo N, Titapun A, Pairojkul C, Saya H, Yongvanit P. CD44 variant-dependent redox status regulation in liver fluke-associated cholangiocarcinoma: A target for cholangiocarcinoma treatment. Cancer Sci 2016; 107:991-1000. [PMID: 27176078 PMCID: PMC4946726 DOI: 10.1111/cas.12967] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 05/04/2016] [Accepted: 05/11/2016] [Indexed: 12/13/2022] Open
Abstract
Expression of CD44, especially the variant isoforms (CD44v) of this major cancer stem cell marker, contributes to reactive oxygen species (ROS) defense through stabilizing xCT (a cystine–glutamate transporter) and promoting glutathione synthesis. This enhances cancer development and increases chemotherapy resistance. We investigate the role of CD44v in the regulation of the ROS defense system in cholangiocarcinoma (CCA). Immunohistochemical staining of CD44v and p38MAPK (a major ROS target) expression in Opisthorchis viverrini‐induced hamster CCA tissues (at 60, 90, 120, and 180 days) reveals a decreased phospho‐p38MAPK signal, whereas the CD44v signal was increased during bile duct transformation. Patients with CCA showed CD44v overexpression and negative‐phospho‐p38MAPK patients a significantly shorter survival rate than the low CD44v signal and positive‐phospho‐p38MAPK patients (P = 0.030). Knockdown of CD44 showed that xCT and glutathione levels were decreased, leading to a high level of ROS. We examined xCT‐targeted CD44v cancer stem cell therapy using sulfasalazine. Glutathione decreased and ROS increased after the treatment, leading to inhibition of cell proliferation and induction of cell death. Thus, the accumulation of CD44v leads to the suppression of p38MAPK in transforming bile duct cells. The redox status regulation of CCA cells depends on the expression of CD44v to contribute the xCT function and is a link to the poor prognosis of patients. Thus, an xCT inhibitor could inhibit cell growth and activate cell death. This suggests that an xCT‐targeting drug may improve CCA therapy by sensitization to the available drug (e.g. gemcitabine) by blocking the mechanism of the cell's ROS defensive system.
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Affiliation(s)
- Malinee Thanee
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Watcharin Loilome
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Anchalee Techasen
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Eiji Sugihara
- Division of Gene Regulation, Institute for Advanced Medical Research, School of Medicine, Keio University, Tokyo, Japan
| | - Shogo Okazaki
- Division of Gene Regulation, Institute for Advanced Medical Research, School of Medicine, Keio University, Tokyo, Japan
| | - Shinya Abe
- Cell Biology Laboratory, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, Higashiosaka, Japan.,Laboratory of Biological Protection, Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Shiho Ueda
- Cell Biology Laboratory, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, Higashiosaka, Japan
| | - Takashi Masuko
- Cell Biology Laboratory, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, Higashiosaka, Japan
| | - Nisana Namwat
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Narong Khuntikeo
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Department of Surgery, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Attapol Titapun
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Department of Surgery, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Chawalit Pairojkul
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Hideyuki Saya
- Division of Gene Regulation, Institute for Advanced Medical Research, School of Medicine, Keio University, Tokyo, Japan
| | - Puangrat Yongvanit
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
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20
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Bell RL, Hauser S, Rodd ZA, Liang T, Sari Y, McClintick J, Rahman S, Engleman EA. A Genetic Animal Model of Alcoholism for Screening Medications to Treat Addiction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2016; 126:179-261. [PMID: 27055615 PMCID: PMC4851471 DOI: 10.1016/bs.irn.2016.02.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The purpose of this review is to present up-to-date pharmacological, genetic, and behavioral findings from the alcohol-preferring P rat and summarize similar past work. Behaviorally, the focus will be on how the P rat meets criteria put forth for a valid animal model of alcoholism with a highlight on its use as an animal model of polysubstance abuse, including alcohol, nicotine, and psychostimulants. Pharmacologically and genetically, the focus will be on the neurotransmitter and neuropeptide systems that have received the most attention: cholinergic, dopaminergic, GABAergic, glutamatergic, serotonergic, noradrenergic, corticotrophin releasing hormone, opioid, and neuropeptide Y. Herein, we sought to place the P rat's behavioral and neurochemical phenotypes, and to some extent its genotype, in the context of the clinical literature. After reviewing the findings thus far, this chapter discusses future directions for expanding the use of this genetic animal model of alcoholism to identify molecular targets for treating drug addiction in general.
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Affiliation(s)
- R L Bell
- Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, United States.
| | - S Hauser
- Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Z A Rodd
- Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, United States
| | - T Liang
- Indiana University School of Medicine, Indianapolis, IN, United States
| | - Y Sari
- University of Toledo, Toledo, OH, United States
| | - J McClintick
- Center for Medical Genomics, Indiana University School of Medicine, Indianapolis, IN, United States
| | - S Rahman
- Department of Pharmaceutical Sciences, South Dakota State University, Brookings, SD, United States
| | - E A Engleman
- Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, United States
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21
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Lewerenz J, Maher P. Chronic Glutamate Toxicity in Neurodegenerative Diseases-What is the Evidence? Front Neurosci 2015; 9:469. [PMID: 26733784 PMCID: PMC4679930 DOI: 10.3389/fnins.2015.00469] [Citation(s) in RCA: 468] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 11/24/2015] [Indexed: 12/13/2022] Open
Abstract
Together with aspartate, glutamate is the major excitatory neurotransmitter in the brain. Glutamate binds and activates both ligand-gated ion channels (ionotropic glutamate receptors) and a class of G-protein coupled receptors (metabotropic glutamate receptors). Although the intracellular glutamate concentration in the brain is in the millimolar range, the extracellular glutamate concentration is kept in the low micromolar range by the action of excitatory amino acid transporters that import glutamate and aspartate into astrocytes and neurons. Excess extracellular glutamate may lead to excitotoxicity in vitro and in vivo in acute insults like ischemic stroke via the overactivation of ionotropic glutamate receptors. In addition, chronic excitotoxicity has been hypothesized to play a role in numerous neurodegenerative diseases including amyotrophic lateral sclerosis, Alzheimer's disease and Huntington's disease. Based on this hypothesis, a good deal of effort has been devoted to develop and test drugs that either inhibit glutamate receptors or decrease extracellular glutamate. In this review, we provide an overview of the different pathways that are thought to lead to an over-activation of the glutamatergic system and glutamate toxicity in neurodegeneration. In addition, we summarize the available experimental evidence for glutamate toxicity in animal models of neurodegenerative diseases.
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Affiliation(s)
- Jan Lewerenz
- Department of Neurology, Ulm UniversityUlm, Germany
| | - Pamela Maher
- Cellular Neurobiology Laboratory, Salk Institute for Biological StudiesLa Jolla, CA, USA
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22
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Thomas AG, Sattler R, Tendyke K, Loiacono KA, Hansen H, Sahni V, Hashizume Y, Rojas C, Slusher BS. High-Throughput Assay Development for Cystine-Glutamate Antiporter (xc-) Highlights Faster Cystine Uptake than Glutamate Release in Glioma Cells. PLoS One 2015; 10:e0127785. [PMID: 26252954 PMCID: PMC4529246 DOI: 10.1371/journal.pone.0127785] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 04/19/2015] [Indexed: 01/22/2023] Open
Abstract
The cystine-glutamate antiporter (system xc-) is a Na+-independent amino acid transporter that exchanges extracellular cystine for intracellular glutamate. It is thought to play a critical role in cellular redox processes through regulation of intracellular glutathione synthesis via cystine uptake. In gliomas, system xc- expression is universally up-regulated while that of glutamate transporters down-regulated, leading to a progressive accumulation of extracellular glutamate and excitotoxic cell death of the surrounding non-tumorous tissue. Additionally, up-regulation of system xc- in activated microglia has been implicated in the pathogenesis of several neurodegenerative disorders mediated by excess glutamate. Consequently, system xc- is a new drug target for brain cancer and neuroinflammatory diseases associated with excess extracellular glutamate. Unfortunately no potent and selective small molecule system xc- inhibitors exist and to our knowledge, no high throughput screening (HTS) assay has been developed to identify new scaffolds for inhibitor design. To develop such an assay, various neuronal and non-neuronal human cells were evaluated as sources of system xc-. Human glioma cells were chosen based on their high system xc- activity. Using these cells, [14C]-cystine uptake and cystine-induced glutamate release assays were characterized and optimized with respect to cystine and protein concentrations and time of incubation. A pilot screen of the LOPAC/NINDS libraries using glutamate release demonstrated that the logistics of the assay were in place but unfortunately, did not yield meaningful pharmacophores. A larger, HTS campaign using the 384-well cystine-induced glutamate release as primary assay and the 96-well 14C-cystine uptake as confirmatory assay is currently underway. Unexpectedly, we observed that the rate of cystine uptake was significantly faster than the rate of glutamate release in human glioma cells. This was in contrast to the same rates of cystine uptake and glutamate release previously reported in normal human fibroblast cells.
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Affiliation(s)
- Ajit G. Thomas
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States of America
| | - Rita Sattler
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States of America
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States of America
| | - Karen Tendyke
- Next Generation Systems CFU, Eisai Inc., Andover, MA, 01810, United States of America
| | - Kara A. Loiacono
- Next Generation Systems CFU, Eisai Inc., Andover, MA, 01810, United States of America
| | - Hans Hansen
- Next Generation Systems CFU, Eisai Inc., Andover, MA, 01810, United States of America
| | - Vishal Sahni
- Neuroscience and General Medicine PCU, Eisai Inc., Andover, MA, 01810, United States of America
| | - Yutaka Hashizume
- Neuroscience and General Medicine PCU, Eisai Inc., Andover, MA, 01810, United States of America
| | - Camilo Rojas
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States of America
- Department of Comparative Medicine and Molecular Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States of America
- * E-mail: (CR); (BSS)
| | - Barbara S. Slusher
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States of America
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States of America
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States of America
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States of America
- * E-mail: (CR); (BSS)
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Featherstone DE, Yanoga F, Grosjean Y. Accelerated bang recovery in Drosophila genderblind mutants. Commun Integr Biol 2014; 1:14-17. [PMID: 19430543 DOI: 10.4161/cib.1.1.6437] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cystine-glutamate transporters import cystine into cells for glutathione synthesis and protection from oxidative stress, but also export significant amounts of glutamate. Increasing evidence suggests that 'ambient extracellular glutamate' secreted by cystine-glutamate transporters in the nervous system modulates glutamatergic synapse strength and behavior. To date, the only cystine-glutamate transporter mutants examined behaviorally are Drosophila genderblind mutants. These animals contain loss-of-function mutations in the 'genderblind' gene, which encodes an xCT subunit essential for cystine-glutamate transporter function. Genderblind was named based on a mutant courtship phenotype: male genderblind mutants are attracted to normally aversive male pheromones and thus court and attempt to copulate with both male and female partners equally. However, genderblind protein is expressed in many parts of the fly brain and thus might be expected to also regulate other behaviors, including behaviors not related to male courtship or chemosensation. Here, we show that genderblind mutants display faster recovery and increased negative geotaxis after strong mechanical stimuli (e.g., they climb faster and farther after vial banging). This phenotype is displayed by both males and females, consistent with strong genderblind expression in both sexes.
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Affiliation(s)
- David E Featherstone
- Department of Biological Sciences; University of Illinois at Chicago; Chicago, Illinois, USA
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Total cysteine and glutathione determination in hemolymph of individual adult D. melanogaster. Anal Chim Acta 2014; 853:660-667. [PMID: 25467515 DOI: 10.1016/j.aca.2014.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/28/2014] [Accepted: 10/02/2014] [Indexed: 11/22/2022]
Abstract
Determination of thiols, glutathione (GSH) and cysteine (Cys) are important due to their roles in oxidative stress and aging. Oxidants such as soluble O2 and H2O2 promote oxidation of thiols to disulfide (SS) bonded dimers affecting quantitation accuracy. The method presented here reduces disulfide-bonded species followed by fluorescence labelling of the 29.5 (±18.2) nL hemolymph volumes of individual adult Drosophila Melanogaster. The availability of only tens of nanoliter (nL) samples that are also highly volume variant requires efficient sample handling to improve thiol measurements while minimizing sample dilution. The optimized method presented here utilizes defined lengths of capillaries to meter tris(2-carboxyethyl)phosphine reducing reagent and monobromobimane derivatizing reagent volumes enabling Cys and GSH quantitation with only 20-fold dilution. The nL assay developed here was optimized with respect to reagent concentrations, sample dilution, reaction times and temperatures. Separation and identification of the nL thiol mixtures were obtained with capillary electrophoresis-laser induced fluorescence. To demonstrate the capability of this method total Cys and total GSH were measured in the hemolymph collected from individual adult D. Melanogaster. The thiol measurements were used to compare a mutant fly strain with a non-functional cystine-glutamate transporter (xCT) to its background control. The mutant fly, genderblind (gb), carries a non-functional gene for a protein similar to mammalian xCT whose function is not fully understood. Average concentrations obtained for mutant and control flies are 2.19 (±0.22) and 1.94 (±0.34) mM Cys and 2.14 (±0.60) and 2.08 (±0.71) mM GSH, respectively, and are not significantly different (p>0.05). Statistical analysis showed significant differences in total GSH of males and females independent of the xCT mutation. Overall, the method demonstrates an approach for effective chemical characterization of thiols in nL sample volumes.
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25
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Alhaddad H, Das SC, Sari Y. Effects of ceftriaxone on ethanol intake: a possible role for xCT and GLT-1 isoforms modulation of glutamate levels in P rats. Psychopharmacology (Berl) 2014; 231:4049-57. [PMID: 24687412 PMCID: PMC4176549 DOI: 10.1007/s00213-014-3545-y] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 03/12/2014] [Indexed: 12/21/2022]
Abstract
RATIONALE Evidence suggests that glutamate transporter 1 (GLT-1) and cystine/glutamate exchanger transporter (xCT) are critical in maintaining glutamate homeostasis. We have recently demonstrated that ceftriaxone treatment induced upregulation of GLT1 levels and attenuated ethanol intake; however, less is known about the involvement of xCT on ethanol intake. In this study, we investigated the effects of ceftriaxone on the levels of xCT in both continuous and relapse-like ethanol drinking, as well as GLT-1 isoforms, and glutamate aspartate transporter (GLAST) in relapse-like ethanol intake. METHODS P rats received free choice of 15 and 30 % ethanol and water for 5 weeks and then deprived of ethanol for 2 weeks. Rats were treated with ceftriaxone (100 mg/kg, i.p.) or saline during the last 5 days of the 2-week deprivation period. After deprivation period, P rats were re-exposed to free choice of 15 and 30 % ethanol and water for nine consecutive days. A second group of P rats was given continuous ethanol access for 5 weeks, then ceftriaxone (100 mg/kg, i.p.) or saline throughout the week 6. RESULTS Ceftriaxone significantly attenuated relapse-like ethanol intake. Importantly, this effect of ceftriaxone was associated in part with upregulation of the levels of GLT-1a and GLT-1b isoforms and xCT in the prefrontal cortex (PFC) and the nucleus accumbens (NAc). There were no significant differences in GLAST expression among all groups. We also found that ceftriaxone treatment increased xCT levels in both PFC and NAc in continuous ethanol intake. CONCLUSION These findings suggest that xCT and GLT-1 isoforms might be target proteins for the treatment of alcohol dependence.
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26
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Zweygarth E, Josemans AI. L-cysteine replaces microaerophilous culture conditions for the in vitro initiation of Theileria equi. Parasitol Res 2013; 113:433-5. [PMID: 24257973 DOI: 10.1007/s00436-013-3672-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Accepted: 10/25/2013] [Indexed: 11/25/2022]
Abstract
Fifty-one blood samples of carrier horses from Theileria equi-endemic localities in South Africa were used for two different methods of in vitro culture initiation of T. equi parasites. Cultures were initiated either in a oxygen-reduced gas mixture or in a 5% CO2-in-air atmosphere in combination with L-cysteine-supplemented culture medium. Out of the 51 blood samples, 43 and 42 cultures, respectively, became culture positive. A possible explanation for this observation is proposed.
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Affiliation(s)
- E Zweygarth
- Onderstepoort Veterinary Institute, Private Bag X5, Onderstepoort, 0110, South Africa,
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27
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Lewerenz J, Hewett SJ, Huang Y, Lambros M, Gout PW, Kalivas PW, Massie A, Smolders I, Methner A, Pergande M, Smith SB, Ganapathy V, Maher P. The cystine/glutamate antiporter system x(c)(-) in health and disease: from molecular mechanisms to novel therapeutic opportunities. Antioxid Redox Signal 2013; 18:522-55. [PMID: 22667998 PMCID: PMC3545354 DOI: 10.1089/ars.2011.4391] [Citation(s) in RCA: 666] [Impact Index Per Article: 60.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The antiporter system x(c)(-) imports the amino acid cystine, the oxidized form of cysteine, into cells with a 1:1 counter-transport of glutamate. It is composed of a light chain, xCT, and a heavy chain, 4F2 heavy chain (4F2hc), and, thus, belongs to the family of heterodimeric amino acid transporters. Cysteine is the rate-limiting substrate for the important antioxidant glutathione (GSH) and, along with cystine, it also forms a key redox couple on its own. Glutamate is a major neurotransmitter in the central nervous system (CNS). By phylogenetic analysis, we show that system x(c)(-) is a rather evolutionarily new amino acid transport system. In addition, we summarize the current knowledge regarding the molecular mechanisms that regulate system x(c)(-), including the transcriptional regulation of the xCT light chain, posttranscriptional mechanisms, and pharmacological inhibitors of system x(c)(-). Moreover, the roles of system x(c)(-) in regulating GSH levels, the redox state of the extracellular cystine/cysteine redox couple, and extracellular glutamate levels are discussed. In vitro, glutamate-mediated system x(c)(-) inhibition leads to neuronal cell death, a paradigm called oxidative glutamate toxicity, which has successfully been used to identify neuroprotective compounds. In vivo, xCT has a rather restricted expression pattern with the highest levels in the CNS and parts of the immune system. System x(c)(-) is also present in the eye. Moreover, an elevated expression of xCT has been reported in cancer. We highlight the diverse roles of system x(c)(-) in the regulation of the immune response, in various aspects of cancer and in the eye and the CNS.
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Affiliation(s)
- Jan Lewerenz
- Department of Neurology, University of Ulm, Ulm, Germany.
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28
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Yoshikawa M, Tsuchihashi K, Ishimoto T, Yae T, Motohara T, Sugihara E, Onishi N, Masuko T, Yoshizawa K, Kawashiri S, Mukai M, Asoda S, Kawana H, Nakagawa T, Saya H, Nagano O. xCT inhibition depletes CD44v-expressing tumor cells that are resistant to EGFR-targeted therapy in head and neck squamous cell carcinoma. Cancer Res 2013; 73:1855-66. [PMID: 23319806 DOI: 10.1158/0008-5472.can-12-3609-t] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The targeting of antioxidant systems that allow stem-like cancer cells to avoid the adverse consequences of oxidative stress might be expected to improve the efficacy of cancer treatment. Here, we show that head and neck squamous cell carcinoma (HNSCC) cells that express variant isoforms of CD44 (CD44v) rely on the activity of the cystine transporter subunit xCT for control of their redox status. xCT inhibition selectively induces apoptosis in CD44v-expressing tumor cells without affecting CD44v-negative differentiated cells in the same tumor. In contrast to CD44v-expressing undifferentiated cells, CD44v-negative differentiated cells manifest EGF receptor (EGFR) activation and rely on EGFR activity for their survival. Combined treatment with inhibitors of xCT-dependent cystine transport and of EGFR resulted in a synergistic reduction of EGFR-expressing HNSCC tumor growth. Thus, xCT-targeted therapy may deplete CD44v-expressing undifferentiated HNSCC cells and concurrently sensitize the remaining differentiating cells to available treatments including EGFR-targeted therapy.
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Affiliation(s)
- Momoko Yoshikawa
- Division of Gene Regulation, Institute for Advanced Medical Research, School of Medicine, School of Medicine, Keio University, Shinjuku-ku, Japan
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29
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Lim CH, Jeong W, Lim W, Kim J, Song G, Bazer FW. Differential Expression of Select Members of the SLC Family of Genes and Regulation of Expression by MicroRNAs in the Chicken Oviduct1. Biol Reprod 2012; 87:145. [DOI: 10.1095/biolreprod.112.101444] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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30
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Bridges R, Lutgen V, Lobner D, Baker DA. Thinking outside the cleft to understand synaptic activity: contribution of the cystine-glutamate antiporter (System xc-) to normal and pathological glutamatergic signaling. Pharmacol Rev 2012; 64:780-802. [PMID: 22759795 PMCID: PMC3400835 DOI: 10.1124/pr.110.003889] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
System x(c)(-) represents an intriguing target in attempts to understand the pathological states of the central nervous system. Also called a cystine-glutamate antiporter, system x(c)(-) typically functions by exchanging one molecule of extracellular cystine for one molecule of intracellular glutamate. Nonvesicular glutamate released during cystine-glutamate exchange activates extrasynaptic glutamate receptors in a manner that shapes synaptic activity and plasticity. These findings contribute to the intriguing possibility that extracellular glutamate is regulated by a complex network of release and reuptake mechanisms, many of which are unique to glutamate and rarely depicted in models of excitatory signaling. Because system x(c)(-) is often expressed on non-neuronal cells, the study of cystine-glutamate exchange may advance the emerging viewpoint that glia are active contributors to information processing in the brain. It is noteworthy that system x(c)(-) is at the interface between excitatory signaling and oxidative stress, because the uptake of cystine that results from cystine-glutamate exchange is critical in maintaining the levels of glutathione, a critical antioxidant. As a result of these dual functions, system x(c)(-) has been implicated in a wide array of central nervous system diseases ranging from addiction to neurodegenerative disorders to schizophrenia. In the current review, we briefly discuss the major cellular components that regulate glutamate homeostasis, including glutamate release by system x(c)(-). This is followed by an in-depth discussion of system x(c)(-) as it relates to glutamate release, cystine transport, and glutathione synthesis. Finally, the role of system x(c)(-) is surveyed across a number of psychiatric and neurodegenerative disorders.
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Affiliation(s)
- Richard Bridges
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana, USA
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31
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Yae T, Tsuchihashi K, Ishimoto T, Motohara T, Yoshikawa M, Yoshida GJ, Wada T, Masuko T, Mogushi K, Tanaka H, Osawa T, Kanki Y, Minami T, Aburatani H, Ohmura M, Kubo A, Suematsu M, Takahashi K, Saya H, Nagano O. Alternative splicing of CD44 mRNA by ESRP1 enhances lung colonization of metastatic cancer cell. Nat Commun 2012; 3:883. [PMID: 22673910 DOI: 10.1038/ncomms1892] [Citation(s) in RCA: 280] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 05/08/2012] [Indexed: 12/15/2022] Open
Abstract
In cancer metastasis, various environmental stressors attack the disseminating cells. The successful colonization of cancer cells in secondary sites therefore requires the ability of the cells to avoid the consequences of such exposure to the stressors. Here we show that orthotopic transplantation of a CD44 variant isoform-expressing (CD44v(+)) subpopulation of 4T1 breast cancer cells, but not that of a CD44v(-) subpopulation, in mice results in efficient lung metastasis accompanied by expansion of stem-like cancer cells. Such metastasis is dependent on the activity of the cystine transporter xCT, and the stability of this protein is controlled by CD44v. We find that epithelial splicing regulatory protein 1 regulates the expression of CD44v, and knockdown of epithelial splicing regulatory protein 1 in CD44v(+) cells results in an isoform switch from CD44v to CD44 standard (CD44s), leading to reduced cell surface expression of xCT and suppression of lung colonization. The epithelial splicing regulatory protein 1-CD44v-xCT axis is thus a potential therapeutic target for the prevention of metastasis.
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Affiliation(s)
- Toshifumi Yae
- Division of Gene Regulation, Institute for Advanced Medical Research, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
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32
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Ramalingam M, Kim SJ. Reactive oxygen/nitrogen species and their functional correlations in neurodegenerative diseases. J Neural Transm (Vienna) 2012; 119:891-910. [PMID: 22212484 DOI: 10.1007/s00702-011-0758-7] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 12/20/2011] [Indexed: 12/11/2022]
Abstract
The continuous production and efflux of reactive oxygen/nitrogen species from endogenous and exogenous sources can damage biological molecules and initiate a cascade of events. Mitochondria are pivotal in controlling cell survival and death. Cumulative oxidative stress, disrupted mitochondrial respiration, and mitochondrial damage are related with various neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, and others. Biochemical cascades of apoptosis are mediated in signaling molecules, including protein kinases and transcription factors. The expressions in the pro-apoptotic signal transduction networks may indeed promote cell death and degeneration in brain cells. The regulation of that protein phosphorylation by kinases and phosphatases is emerging as a prerequisite mechanism in the control of the apoptotic cell death program. In this review, we attempt to put forth the evidence for possible mechanistic explanations for involvement of free radicals in the pathogenesis of neurodegenerative diseases.
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Affiliation(s)
- Mahesh Ramalingam
- Department of Pharmacology and Toxicology, Metabolic Diseases Research Laboratory, School of Dentistry, Kyung Hee University, #1 Hoegi-dong, Dongdaemun-gu, Seoul, Republic of Korea
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Giraudi PJ, Bellarosa C, Coda-Zabetta CD, Peruzzo P, Tiribelli C. Functional induction of the cystine-glutamate exchanger system Xc(-) activity in SH-SY5Y cells by unconjugated bilirubin. PLoS One 2011; 6:e29078. [PMID: 22216172 PMCID: PMC3246462 DOI: 10.1371/journal.pone.0029078] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Accepted: 11/21/2011] [Indexed: 12/18/2022] Open
Abstract
We have previously reported that exposure of SH-SY5Y neuroblastoma cells to unconjugated bilirubin (UCB) resulted in a marked up-regulation of the mRNA encoding for the Na+ -independent cystine∶glutamate exchanger System Xc− (SLC7A11 and SLC3A2 genes). In this study we demonstrate that SH-SY5Y cells treated with UCB showed a higher cystine uptake due to a significant and specific increase in the activity of System Xc−, without the contribution of the others two cystine transporters (XAG− and GGT) reported in neurons. The total intracellular glutathione content was 2 folds higher in the cells exposed to bilirubin as compared to controls, suggesting that the internalized cystine is used for gluthathione synthesis. Interestingly, these cells were significantly less sensitive to an oxidative insult induced by hydrogen peroxide. If System Xc− is silenced the protection is lost. In conclusion, these results suggest that bilirubin can modulate the gluthathione levels in neuroblastoma cells through the induction of the System Xc−, and this renders the cell less prone to oxidative damage.
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Affiliation(s)
- Pablo J Giraudi
- Centro Studi Fegato, Fondazione Italiana Fegato, Trieste, Italy
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34
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Valdameri G, Trombetta-Lima M, Worfel PR, Pires ARA, Martinez GR, Noleto GR, Cadena SMSC, Sogayar MC, Winnischofer SMB, Rocha MEM. Involvement of catalase in the apoptotic mechanism induced by apigenin in HepG2 human hepatoma cells. Chem Biol Interact 2011; 193:180-9. [PMID: 21756884 DOI: 10.1016/j.cbi.2011.06.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 06/22/2011] [Accepted: 06/28/2011] [Indexed: 02/06/2023]
Abstract
Apigenin has been reported to inhibit proliferation of cancer cells; however, the mechanism underlying its action is not completely understood. Here, we evaluated the effects of apigenin on the levels of expression and activity of antioxidant enzymes, and the involvement of ROS in the mechanism of cell death induced by apigenin in HepG2 human hepatoma cells. Upon treatment with apigenin, HepG2 cells displayed a reduction in cell viability in a dose- and time-dependent manner, and some morphological changes. In addition, apigenin treatment induced ROS generation and significantly decreased the mRNA levels and activity of catalase and levels of intracellular GSH. On the other hand, apigenin treatment did not alter the expression or activity levels of other antioxidant enzymes. Addition of exogenous catalase significantly reduced the effects of apigenin on HepG2 cell death. We also demonstrated that HepG2 cells are more sensitive to apigenin-mediated cell death than are primary cultures of mouse hepatocytes, suggesting a differential toxic effect of this agent in tumor cells. Our results suggest that apigenin-induced apoptosis in HepG2 cells may be mediated by a H(2)O(2)-dependent pathway via reduction of the antioxidant defenses.
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Affiliation(s)
- Glaucio Valdameri
- Department of Biochemistry and Molecular Biology, Federal University of Paraná, Curitiba, PR, Brazil
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35
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Baird L, Dinkova-Kostova AT. The cytoprotective role of the Keap1-Nrf2 pathway. Arch Toxicol 2011; 85:241-72. [PMID: 21365312 DOI: 10.1007/s00204-011-0674-5] [Citation(s) in RCA: 734] [Impact Index Per Article: 56.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 02/08/2011] [Indexed: 12/11/2022]
Abstract
An elaborate network of highly inducible proteins protects aerobic cells against the cumulative damaging effects of reactive oxygen intermediates and toxic electrophiles, which are the major causes of neoplastic and chronic degenerative diseases. These cytoprotective proteins share common transcriptional regulation, through the Keap1-Nrf2 pathway, which can be activated by various exogenous and endogenous small molecules (inducers). Inducers chemically react with critical cysteine residues of the sensor protein Keap1, leading to stabilisation and nuclear translocation of transcription factor Nrf2, and ultimately to coordinate enhanced expression of genes coding for cytoprotective proteins. In addition, inducers inhibit pro-inflammatory responses, and there is a linear correlation spanning more than six orders of magnitude of concentrations between inducer and anti-inflammatory activity. Genetic deletion of transcription factor Nrf2 renders cells and animals much more sensitive to the damaging effects of electrophiles, oxidants and inflammatory agents in comparison with their wild-type counterparts. Conversely, activation of the Keap1-Nrf2 pathway allows survival and adaptation under various conditions of stress and has protective effects in many animal models. Cross-talks with other signalling pathways broadens the role of the Keap1-Nrf2 pathway in determining the fate of the cell, impacting fundamental biological processes such as proliferation, apoptosis, angiogenesis and metastasis.
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Affiliation(s)
- Liam Baird
- Biomedical Research Institute, University of Dundee, Dundee, Scotland, UK
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36
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Featherstone DE. Glial solute carrier transporters in Drosophila and mice. Glia 2010; 59:1351-63. [PMID: 21732427 DOI: 10.1002/glia.21085] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Accepted: 09/07/2010] [Indexed: 01/17/2023]
Abstract
Glia regulate brain physiology primarily by regulating the movement and concentration of substances in the extracellular fluid. Therefore, one approach to understanding the role of glia in brain physiology is to study what happens when glial transporters are removed or modified. The largest and most highly conserved class of transporter is solute carrier (SLC) proteins. SLC proteins are highly expressed in brain, and many are found in glia. The function of many SLC proteins in the brain--particularly in glia--is very poorly understood. SLC proteins can be relatively easily knocked out or modified in genetic model organisms to better understand glial function. Drosophila are popular genetic model organisms that offer a nice balance between genetic malleability and brain complexity. They are ideal for such an endeavor. This article lists and discusses SLC transporter family members that are expressed in both mouse and Drosophila glia, in an effort to provide a foundation for studies of glial SLC transporters using Drosophila as a model.
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Affiliation(s)
- David E Featherstone
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.
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New concept in nutrition for the maintenance of the aging eye redox regulation and therapeutic treatment of cataract disease; synergism of natural antioxidant imidazole-containing amino acid-based compounds, chaperone, and glutathione boosting agents: a systemic perspective on aging and longevity emerged from studies in humans. Am J Ther 2010; 17:373-89. [PMID: 20463577 DOI: 10.1097/mjt.0b013e3181d6b6c3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Cataract, opacification of the lens, is one of the commonest causes of loss of useful vision during aging, with an estimated 16 million people world-wide affected. The role of nutritional supplementation in prevention of onset or progression of ocular disease is of interest to health care professionals and patients. The aging eye seems to be at considerable risk from oxidative stress. This review outlines the potential role of the new nutritional strategy on redox balance in age-related eye diseases and detail how the synergism and interaction of imidazole-containing amino acid-based compounds (nonhydrolized L-carnosine, histidine), chaperone agents (such as, L-carnosine, D-pantethine), glutathione-boosting agents (N-acetylcysteine, vitamin E, methionine), and N-acetylcarnosine eye drops plays key roles in the function and maintenance of the redox systems in the aging eye and in the treatment of human cataract disease. A novel patented oral health supplement is presented which enhances the anticataract activity of eye drops and activates functional visual acuity. The clinical data demonstrate the effectiveness and safety of a combined oral health care treatment with amino acids possessing chaperone-like activity with N-acetylcarnosine lubricant eye drops. L-carnosine and N-acetylcarnosine protected the chaperone activity of alpha-crystallin and reduced the increased posttranslational modifications of lens proteins. Biological activities of the nonhydrolyzed carnosine in the oral formulation are based on its antioxidant and antiglycating (transglycating) action that, in addition to heavy metal chelation and pH-buffering ability, makes carnosine an essential factor for preventing sight-threatening eye disorders having oxidative stress in their pathogenesis, neurodegeneration, and accumulation of senile features. The findings suggest that synergism is required between carnosine or other imidazole-containing compounds and reduced glutathione in tissues and cells for efficacious protection from protein carbonylation as a biomarker for the ability of the non-toxic compounds to reduce oxidative stress. Potential therapeutic applications of oral forms of nonhydrolized carnosine and their specific mechanisms to manage telomere attrition and vascular aging might help elderly patients to withstand the problems of sight-threatening eye diseases related to oxidative stress and accelerated biological ageing in linked with earlier onset of diseases.
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D'Angelo JA, Dehlink E, Platzer B, Dwyer P, Circu ML, Garay J, Aw TY, Fiebiger E, Dickinson BL. The cystine/glutamate antiporter regulates dendritic cell differentiation and antigen presentation. THE JOURNAL OF IMMUNOLOGY 2010; 185:3217-26. [PMID: 20733204 DOI: 10.4049/jimmunol.1001199] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The major cellular antioxidant glutathione is depleted during HIV infection and in obesity. Although the consequence of glutathione depletion on immune function is starting to emerge, it is currently not known whether glutathione dysregulation influences the differentiation and maturation of dendritic cells (DCs). Moreover, the effect of glutathione depletion on DC effector functions, such as Ag presentation, is poorly understood. Glutathione synthesis depends on the cystine/glutamate antiporter, which transports the rate-limiting precursor cystine into the cell in exchange for glutamate. In this paper, we present a detailed study of antiporter function in DCs and demonstrate a role for the antiporter in DC differentiation and cross-presentation. We show that the antiporter is the major mechanism for transport of cystine and glutamate and modulates the intracellular glutathione content and glutathione efflux from DCs. Blocking antiporter-dependent cystine transport decreases intracellular glutathione levels, and these effects correlate with reduced transcription of the functional subunit of the antiporter. We further demonstrate that blocking antiporter activity interferes with DC differentiation from monocyte precursors, but antiporter activity is not required for LPS-induced phenotypic maturation. Finally, we show that inhibiting antiporter uptake of cystine interferes with presentation of exogenous Ag to class II MHC-restricted T cells and blocks cross-presentation on MHC class I. We conclude that aberrant antiporter function disrupts glutathione homeostasis in DCs and may contribute to impaired immunity in the diseased host.
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Affiliation(s)
- June A D'Angelo
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Science Center, New Orleans, LA 70112, USA
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39
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Hu RG, Lim J, Donaldson PJ, Kalloniatis M. Characterization of the cystine/glutamate transporter in the outer plexiform layer of the vertebrate retina. Eur J Neurosci 2008; 28:1491-502. [DOI: 10.1111/j.1460-9568.2008.06435.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Denninger V, Koopmann R, Muhammad K, Barth T, Bassarak B, Schönfeld C, Kilunga BK, Duszenko M. Chapter Twenty‐Five Kinetoplastida. Methods Enzymol 2008; 451:373-408. [DOI: 10.1016/s0076-6879(08)03225-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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41
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Lastro M, Kourtidis A, Farley K, Conklin DS. xCT expression reduces the early cell cycle requirement for calcium signaling. Cell Signal 2007; 20:390-9. [PMID: 18054200 DOI: 10.1016/j.cellsig.2007.10.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2007] [Accepted: 10/30/2007] [Indexed: 12/24/2022]
Abstract
Calcium has long been recognized as an important regulator of cell cycle transitions although the mechanisms are largely unknown. A functional genomic screen has identified genes involved in the regulation of early cell cycle progression by calcium. These genes when overexpressed confer the ability to bypass the G1/S arrest induced by Ca(2+)-channel antagonists in mouse fibroblasts. Overexpression of the cystine-glutamate exchanger, xCT, had the greatest ability to evade calcium antagonist-induced cell cycle arrest. xCT carries out the rate limiting step of glutathione synthesis in many cell types and is responsible for the uptake of cystine in most human cancer cell lines. Functional analysis indicates that the cystine uptake activity of xCT overcomes the G1/S arrest induced by Ca(2+)-channel antagonists by bypassing the requirement for calcium signaling. Since cells overexpressing xCT were found to have increased levels and activity of the AP-1 transcription factor in G1, redox stimulation of AP-1 activity accounts for the observed growth of these cells in the presence of calcium channel antagonists. These results suggest that reduced calcium signaling impairs AP-1 activation and that xCT expression may directly affect cell proliferation.
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Affiliation(s)
- Michele Lastro
- Department of Biomedical Sciences, Gen*NY*Sis Center for Excellence in Cancer Genomics, University at Albany, State University of New York, Room 210, One Discovery Drive, Rensselaer, NY 12144-3456, United States
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42
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Featherstone DE, Shippy SA. Regulation of synaptic transmission by ambient extracellular glutamate. Neuroscientist 2007; 14:171-81. [PMID: 17947494 DOI: 10.1177/1073858407308518] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Many neuroscientists assume that ambient extracellular glutamate concentrations in the nervous system are biologically negligible under nonpathological conditions. This assumption is false. Hundreds of studies over several decades suggest that ambient extracellular glutamate levels in the intact mammalian brain are approximately 0.5 to approximately 5 microM. This has important implications. Glutamate receptors are desensitized by glutamate concentrations significantly lower than needed for receptor activation; 0.5 to 5 microM of glutamate is high enough to cause constitutive desensitization of most glutamate receptors. Therefore, most glutamate receptors in vivo may be constitutively desensitized, and ambient extracellular glutamate and receptor desensitization may be potent but generally unrecognized regulators of synaptic transmission. Unfortunately, the mechanisms regulating ambient extracellular glutamate and glutamate receptor desensitization remain poorly understood and understudied.
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Affiliation(s)
- David E Featherstone
- Department of Biological Sciences, University of Illinois at Chicago 60607, USA.
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43
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Banjac A, Perisic T, Sato H, Seiler A, Bannai S, Weiss N, Kölle P, Tschoep K, Issels RD, Daniel PT, Conrad M, Bornkamm GW. The cystine/cysteine cycle: a redox cycle regulating susceptibility versus resistance to cell death. Oncogene 2007; 27:1618-28. [PMID: 17828297 DOI: 10.1038/sj.onc.1210796] [Citation(s) in RCA: 224] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The glutathione-dependent system is one of the key systems regulating cellular redox balance, and thus cell fate. Cysteine, typically present in its oxidized form cystine in the extracellular space, is regarded as the rate-limiting substrate for glutathione (GSH) synthesis. Cystine is transported into cells by the highly specific amino-acid antiporter system xc-. Since Burkitt's Lymphoma (BL) cells display limited uptake capacity for cystine, and are thus prone to oxidative stress-induced cell death, we stably expressed the substrate-specific subunit of system xc-, xCT, in HH514 BL cells. xCT-overexpressing cells became highly resistant to oxidative stress, particularly upon GSH depletion. Contrary to previous predictions, the increase of intracellular cysteine did not affect the cellular GSH pool, but concomitantly boosted extracellular cysteine concentrations. Even though cells were depleted of bulk GSH, xCT overexpression maintained cellular integrity by protecting against lipid peroxidation, a very early event in cell death progression. Our results show that system xc- protects against oxidative stress not by elevating intracellular GSH levels, but rather creates a reducing extracellular environment by driving a highly efficient cystine/cysteine redox cycle. Our findings show that the cystine/cysteine redox cycle by itself must be viewed as a discrete major regulator of cell survival.
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Affiliation(s)
- A Banjac
- GSF-Forschungszentrum für Umwelt und Gesundheit, Institut für Klinische Molekularbiologie und Tumorgenetik, München, Germany
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44
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Sagara JI, Makino N. Glutathione induces neuronal differentiation in rat bone marrow stromal cells. Neurochem Res 2007; 33:16-21. [PMID: 17594517 DOI: 10.1007/s11064-007-9400-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Accepted: 05/30/2007] [Indexed: 10/23/2022]
Abstract
It has been reported that rat bone marrow stromal cells (BMSCs) are differentiated into neuronal cells by administration of 2-mercaptoethanol [Woodbury et al (2000) J Neurosci Res 61:364-370]. In this study, we examined the effects of various sulfhydryl (SH) compounds on the differentiation of BMSCs obtained from rat femurs. Neuronal differentiation was detected morphologically and immunocytochemically. It was found that the cells treated with reduced glutathione (GSH) apparently differentiated into neurons, showing extensive processes, and expressing neuron-specific enolase and microtubule-associated protein 2. Glutathione monoethyl ester (GEE), which increased the cellular GSH content, showed no effect on the expression of neuronal markers. It is concluded that the neural differentiation of BMSCs occurs by the administration of GSH. It was suggested that extracellular and not intracellular GSH have effects on the induction of the neuronal differentiation of BMSCs.
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Affiliation(s)
- Jun-ichi Sagara
- Center for Medical Sciences, Ibaraki Prefectural University of Health Sciences, Ami, Ibaraki 300-0394, Japan.
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Anderson CL, Iyer SS, Ziegler TR, Jones DP. Control of extracellular cysteine/cystine redox state by HT-29 cells is independent of cellular glutathione. Am J Physiol Regul Integr Comp Physiol 2007; 293:R1069-75. [PMID: 17567723 DOI: 10.1152/ajpregu.00195.2007] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human cell lines regulate the redox state (E(h)) of the cysteine/cystine (Cys/CySS) couple in culture medium to approximately -80 mV, a value similar to the average E(h) for Cys/CySS in human plasma. The mechanisms involved in regulation of extracellular E(h) of Cys/CySS are not known, but GSH is released from tissues at rates proportional to tissue GSH concentration, and this released GSH could react with CySS to contribute to maintenance of this balance. The present study was undertaken to determine whether depletion of cellular GSH alters regulation of extracellular Cys/CySS E(h). Decrease of GSH in HT-29 cells by inhibiting synthesis with l-buthionine-[S,R]-sulfoximine showed no effect on the rate of reduction of extracellular CySS to achieve a stable E(h) for Cys/CySS in the culture medium. Limiting Cys and CySS in the culture medium also substantially decreased cellular GSH but resulted in no significant effect on extracellular Cys/CySS E(h). Addition of CySS to these cells showed that extracellular Cys/CySS E(h) approached -80 mV at 4 h while cellular GSH and extracellular GSH/GSSG E(h) recovered more slowly. Together, these results show that HT-29 cells have the capacity to regulate the extracellular Cys/CySS E(h) by mechanisms that are independent of cellular GSH. The results suggest that transport systems for Cys and CySS and/or membranal oxidoreductases could be more important than cellular GSH in regulation of extracellular Cys/CySS E(h).
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Affiliation(s)
- Corinna L Anderson
- Department of Medicine/Pulmonary, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322, USA
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46
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Breyer A, Elstner M, Gillessen T, Weiser D, Elstner E. Glutamate-induced cell death in neuronal HT22 cells is attenuated by extracts from St. John's wort (Hypericum perforatum L.). PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2007; 14:250-5. [PMID: 17346956 DOI: 10.1016/j.phymed.2007.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Glutamate-induced cell death of hippocampal HT22 cells is a model system for neuronal disorders due to depletion of glutathione levels and increase of intracellular reactive oxygen species. Standardized extracts of Hypericum perforatum (HPE) contain flavonoids known for antioxidative properties. In the above model, cytoprotective effects at a concentration of 0.05% HPE by attenuation of calcium fluxes and cellular energy statuses are reported.
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Affiliation(s)
- Anja Breyer
- Institute of Phytopathology, Laboratory of Applied Biochemistry, Technical University of Munich, Munich, Germany
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Augustin H, Grosjean Y, Chen K, Sheng Q, Featherstone DE. Nonvesicular release of glutamate by glial xCT transporters suppresses glutamate receptor clustering in vivo. J Neurosci 2007; 27:111-23. [PMID: 17202478 PMCID: PMC2193629 DOI: 10.1523/jneurosci.4770-06.2007] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We hypothesized that cystine/glutamate transporters (xCTs) might be critical regulators of ambient extracellular glutamate levels in the nervous system and that misregulation of this glutamate pool might have important neurophysiological and/or behavioral consequences. To test this idea, we identified and functionally characterized a novel Drosophila xCT gene, which we subsequently named "genderblind" (gb). Genderblind is expressed in a previously overlooked subset of peripheral and central glia. Genetic elimination of gb causes a 50% reduction in extracellular glutamate concentration, demonstrating that xCT transporters are important regulators of extracellular glutamate. Consistent with previous studies showing that extracellular glutamate regulates postsynaptic glutamate receptor clustering, gb mutants show a large (200-300%) increase in the number of postsynaptic glutamate receptors. This increase in postsynaptic receptor abundance is not accompanied by other obvious synaptic changes and is completely rescued when synapses are cultured in wild-type levels of glutamate. Additional in situ pharmacology suggests that glutamate-mediated suppression of glutamate receptor clustering depends on receptor desensitization. Together, our results suggest that (1) xCT transporters are critical for regulation of ambient extracellular glutamate in vivo; (2) ambient extracellular glutamate maintains some receptors constitutively desensitized in vivo; and (3) constitutive desensitization of ionotropic glutamate receptors suppresses their ability to cluster at synapses.
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Affiliation(s)
- Hrvoje Augustin
- Biological Sciences, University of Illinois at Chicago, Chicago, Illinois 60607, USA
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48
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Gras G, Porcheray F, Samah B, Leone C. The glutamate-glutamine cycle as an inducible, protective face of macrophage activation. J Leukoc Biol 2006; 80:1067-75. [PMID: 16912070 DOI: 10.1189/jlb.0306153] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Neuronal damage in HIV infection results mainly from chronic activation of brain tissue and involves inflammation, oxidative stress, and glutamate-related neurotoxicity. Glutamate toxicity acts via two distinct pathways: an excitotoxic one, in which glutamate receptors are hyperactivated, and an oxidative one, in which cystine uptake is inhibited, resulting in glutathione depletion, oxidative stress, and cell degeneration. A number of studies have shown that astrocytes normally take up glutamate, keeping extracellular glutamate concentration low in the brain and preventing excitotoxicity. They, in turn, provide the trophic amino acid glutamine via their expression of glutamine synthetase. These protective and trophic actions are inhibited in HIV infection, probably as a result of the effects of inflammatory mediators and viral proteins. In vitro and in vivo studies have demonstrated that activated microglia and brain macrophages (AMM) express the transporters and enzymes of the glutamate cycle. This suggests that in addition to their recognized neurotoxic properties in HIV infection, these cells exhibit some neuroprotective properties, which may partly compensate for the inhibited astrocytic function. This hypothesis might explain the discrepancy between microglial activation, which occurs early in the disease, and neuronal apoptosis and neuronal loss, which are late events. In this review, we discuss the possible neuroprotective and neurotrophic roles of AMM and their relationships with inflammation and oxidative stress.
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Affiliation(s)
- Gabriel Gras
- CEA, DSV, DRM, SNV, UMR E-01 Université Paris-Sud XI, Laboratoire de Neuro-Immuno-Virologie, F92265 Fontenay-aux Roses, France.
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49
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Obrigkeit DH, Oepen T, Jugert FK, Merk HF, Kubicki J. Xenobiotics in vitro: the influence of L-cystine, pantothenat, and miliacin on metabolic and proliferative capacity of keratinocytes. Cutan Ocul Toxicol 2006; 25:13-22. [PMID: 16702051 DOI: 10.1080/15569520500536584] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
To investigate the effect of cell growth-stimulating agents on human epidermal keratinocytes, we exposed monolayers of normal human keratinocytes derived from foreskin to different concentrations of the amino acid L-cystine, the member of the vitamin B family D-pantothenat, the phytosterol miliacin, and a combination thereof in keratinocyte growth medium. As a test system for the metabolic capacity, we used the activity of mitochondrial deyhdrogenases as measured by XTT, and for the cell proliferation, we determined the BrdU-uptake. The additives, active ingredients of the hair growth drug PRIORIN, were added in the presence of fully supplemented keratinocyte growth medium or a deficient medium without L-cystine, L-methionine, L-histidin, D-pantothenat, epidermal growth factor, and bovine pituary gland extract. Deficient medium itself reduced the metabolic capacity of keratinocytes to 35% compared with keratinocytes in fully supplemented growth medium. In deficient medium cell, proliferation was not measurable. Increasing doses of L-cystine restored the reduced metabolic capacity from 46% (0.009 mg/L) to 54% (0.09 mg/L) and 92% (0.45 mg/L) in deficient medium. Addition of D-pantothenat (0.43 mg/L) enhanced the metabolic capacity to 150% only in fully supplemented growth medium, compared with untreated controls with growth medium. Miliacin (6 mg/mL) increased not only the metabolic capacity (162%) but also stimulated cell proliferation (215%) as measured by BrdU-uptake in growth medium. The combination of all three additives increased the metabolic capacity (245%) synergistically in growth medium. We were able to show effects of D-panthenol, L-lysine, and miliacin on proliferation and metabolic capacity of keratinocyte monocell culture, which was further increased by combination of the three substances. These basic results suggest a beneficial effect on keratinocyte growth and stimulation by products combining these substances (e.g., Priorin). Furthermore, this work emphasizes the suitability of keratinocyte monolayers for pharmacological testings.
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Affiliation(s)
- D Hoeller Obrigkeit
- Department of Dermatology and Allergology, University Clinic RWTH, Aachen, Germany
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50
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Gras G, Chrétien F, Vallat-Decouvelaere AV, Le Pavec G, Porcheray F, Bossuet C, Léone C, Mialocq P, Dereuddre-Bosquet N, Clayette P, Le Grand R, Créminon C, Dormont D, Rimaniol AC, Gray F. Regulated expression of sodium-dependent glutamate transporters and synthetase: a neuroprotective role for activated microglia and macrophages in HIV infection? Brain Pathol 2006; 13:211-22. [PMID: 12744474 PMCID: PMC8095782 DOI: 10.1111/j.1750-3639.2003.tb00020.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
It is now widely accepted that neuronal damage in HIV infection results mainly from microglial activation and involves apoptosis, oxidative stress and glutamate-mediated neurotoxicity. Glutamate toxicity acts via 2 distinct pathways: an excitotoxic one in which glutamate receptors are hyperactivated, and an oxidative one in which cystine uptake is inhibited, resulting in glutathione depletion and oxidative stress. A number of studies show that astrocytes normally take up glutamate, keeping extracellular glutamate concentration low in the brain and preventing excitotoxicity. This action is inhibited in HIV infection, probably due to the effects of inflammatory mediators and viral proteins. Other in vitro studies as well as in vivo experiments in rodents following mechanical stimulation, show that activated microglia and brain macrophages express high affinity glutamate transporters. These data have been confirmed in chronic inflammation of the brain, particularly in SIV infection, where activated microglia and brain macrophages also express glutamine synthetase. Recent studies in humans with HIV infection show that activated microglia and brain macrophages express the glutamate transporter EAAT-1 and that expression varies according to the disease stage. This suggests that, besides their recognized neurotoxic properties in HIV infection, these cells also have a neuroprotective function, and may partly make up for the inhibited astrocytic function, at least temporarily. This hypothesis might explain the discrepancy between microglial activation which occurs early in the disease, and neuronal apoptosis and neuronal loss which is a late event. In this review article, we discuss the possible neuroprotective and neurotrophic roles of activated microglia and macrophages that may be generated by the expression of high affinity glutamate transporters and glutamine synthetase, 2 major effectors of glial glutamate metabolism, and the implications for HIV-induced neuronal dysfunction, the underlying cause of HIV dementia.
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Affiliation(s)
- Gabriel Gras
- CEA, Service de Neurovirologie, DSV/DRM, Centre de Recherches du Service de Santé des Armées, EPHE, IPSC, 92265 Fontenay aux Roses cedex, France.
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