1
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Jakobsen S, Nielsen CU. Exploring Amino Acid Transporters as Therapeutic Targets for Cancer: An Examination of Inhibitor Structures, Selectivity Issues, and Discovery Approaches. Pharmaceutics 2024; 16:197. [PMID: 38399253 PMCID: PMC10893028 DOI: 10.3390/pharmaceutics16020197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/18/2024] [Accepted: 01/28/2024] [Indexed: 02/25/2024] Open
Abstract
Amino acid transporters are abundant amongst the solute carrier family and have an important role in facilitating the transfer of amino acids across cell membranes. Because of their impact on cell nutrient distribution, they also appear to have an important role in the growth and development of cancer. Naturally, this has made amino acid transporters a novel target of interest for the development of new anticancer drugs. Many attempts have been made to develop inhibitors of amino acid transporters to slow down cancer cell growth, and some have even reached clinical trials. The purpose of this review is to help organize the available information on the efforts to discover amino acid transporter inhibitors by focusing on the amino acid transporters ASCT2 (SLC1A5), LAT1 (SLC7A5), xCT (SLC7A11), SNAT1 (SLC38A1), SNAT2 (SLC38A2), and PAT1 (SLC36A1). We discuss the function of the transporters, their implication in cancer, their known inhibitors, issues regarding selective inhibitors, and the efforts and strategies of discovering inhibitors. The goal is to encourage researchers to continue the search and development within the field of cancer treatment research targeting amino acid transporters.
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Affiliation(s)
- Sebastian Jakobsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense, Denmark
| | - Carsten Uhd Nielsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense, Denmark
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2
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Ferrada E, Wiedmer T, Wang WA, Frommelt F, Steurer B, Klimek C, Lindinger S, Osthushenrich T, Garofoli A, Brocchetti S, Bradberry S, Huang J, MacNamara A, Scarabottolo L, Ecker GF, Malarstig A, Superti-Furga G. Experimental and Computational Analysis of Newly Identified Pathogenic Mutations in the Creatine Transporter SLC6A8. J Mol Biol 2024; 436:168383. [PMID: 38070861 DOI: 10.1016/j.jmb.2023.168383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/26/2023] [Accepted: 12/01/2023] [Indexed: 12/24/2023]
Abstract
Creatine is an essential metabolite for the storage and rapid supply of energy in muscle and nerve cells. In humans, impaired metabolism, transport, and distribution of creatine throughout tissues can cause varying forms of mental disability, also known as creatine deficiency syndrome (CDS). So far, 80 mutations in the creatine transporter (SLC6A8) have been associated to CDS. To better understand the effect of human genetic variants on the physiology of SLC6A8 and their possible impact on CDS, we studied 30 missense variants including 15 variants of unknown significance, two of which are reported here for the first time. We expressed these variants in HEK293 cells and explored their subcellular localization and transport activity. We also applied computational methods to predict variant effect and estimate site-specific changes in thermodynamic stability. To explore variants that might have a differential effect on the transporter's conformers along the transport cycle, we constructed homology models of the inward facing, and outward facing conformations. In addition, we used mass-spectrometry to study proteins that interact with wild type SLC6A8 and five selected variants in HEK293 cells. In silico models of the protein complexes revealed how two variants impact the interaction interface of SLC6A8 with other proteins and how pathogenic variants lead to an enrichment of ER protein partners. Overall, our integrated analysis disambiguates the pathogenicity of 15 variants of unknown significance revealing diverse mechanisms of pathogenicity, including two previously unreported variants obtained from patients suffering from the creatine deficiency syndrome.
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Affiliation(s)
- Evandro Ferrada
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria.
| | - Tabea Wiedmer
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Wen-An Wang
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Fabian Frommelt
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Barbara Steurer
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Christoph Klimek
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Sabrina Lindinger
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | | | - Andrea Garofoli
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | | | | | - Jiahui Huang
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | | | | | - Gerhard F Ecker
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Anders Malarstig
- Pfizer Worldwide Research, Development and Medical, Stockholm, Sweden
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria; Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
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3
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Audet-Delage Y, St-Louis C, Minarrieta L, McGuirk S, Kurreal I, Annis MG, Mer AS, Siegel PM, St-Pierre J. Spatiotemporal modeling of chemoresistance evolution in breast tumors uncovers dependencies on SLC38A7 and SLC46A1. Cell Rep 2023; 42:113191. [PMID: 37792528 DOI: 10.1016/j.celrep.2023.113191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 08/17/2023] [Accepted: 09/15/2023] [Indexed: 10/06/2023] Open
Abstract
In solid tumors, drug concentrations decrease with distance from blood vessels. However, cellular adaptations accompanying the gradated exposure of cancer cells to drugs are largely unknown. Here, we modeled the spatiotemporal changes promoting chemotherapy resistance in breast cancer. Using pairwise cell competition assays at each step during the acquisition of chemoresistance, we reveal an important priming phase that renders cancer cells previously exposed to sublethal drug concentrations refractory to dose escalation. Therapy-resistant cells throughout the concentration gradient display higher expression of the solute carriers SLC38A7 and SLC46A1 and elevated intracellular concentrations of their associated metabolites. Reduced levels of SLC38A7 and SLC46A1 diminish the proliferative potential of cancer cells, and elevated expression of these SLCs in breast tumors from patients correlates with reduced survival. Our work provides mechanistic evidence to support dose-intensive treatment modalities for patients with solid tumors and reveals two members of the SLC family as potential actionable targets.
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Affiliation(s)
- Yannick Audet-Delage
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Catherine St-Louis
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Lucía Minarrieta
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Shawn McGuirk
- Department of Biochemistry, McGill University, Montréal, QC H3G 1Y6, Canada; Goodman Cancer Institute, McGill University, Montréal, QC H3A 1A3, Canada
| | - Irwin Kurreal
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Matthew G Annis
- Goodman Cancer Institute, McGill University, Montréal, QC H3A 1A3, Canada; Department of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Arvind Singh Mer
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Peter M Siegel
- Goodman Cancer Institute, McGill University, Montréal, QC H3A 1A3, Canada; Department of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
| | - Julie St-Pierre
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; Department of Biochemistry, McGill University, Montréal, QC H3G 1Y6, Canada.
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4
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Tury S, Chauveau L, Lecante A, Courgnaud V, Battini JL. A co-opted endogenous retroviral envelope promotes cell survival by controlling CTR1-mediated copper transport and homeostasis. Cell Rep 2023; 42:113065. [PMID: 37682705 DOI: 10.1016/j.celrep.2023.113065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 06/14/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
Copper is a critical element for eukaryotic life involved in numerous cellular functions, including redox balance, but is toxic in excess. Therefore, tight regulation of copper acquisition and homeostasis is essential for cell physiology and survival. Here, we identify a different regulatory mechanism for cellular copper homeostasis that requires the presence of an endogenous retroviral envelope glycoprotein called Refrex1. We show that cells respond to elevated extracellular copper by increasing the expression of Refrex1, which regulates copper acquisition through interaction with the main copper transporter CTR1. Downmodulation of Refrex1 results in intracellular copper accumulation leading to reactive oxygen species (ROS) production and subsequent apoptosis, which is prevented by copper chelator treatment. Our results show that Refrex1 has been co-opted for its ability to regulate copper entry through CTR1 in order to limit copper excess, redox imbalance, and ensuing cell death, strongly suggesting that other endogenous retroviruses may have similar metabolic functions among vertebrates.
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Affiliation(s)
- Sandrine Tury
- Institut de Recherche en Infectiologie de Montpellier IRIM - CNRS UMR 9004, Université Montpellier, 34293 Montpellier Cedex 5, France
| | - Lise Chauveau
- Institut de Recherche en Infectiologie de Montpellier IRIM - CNRS UMR 9004, Université Montpellier, 34293 Montpellier Cedex 5, France
| | - Arnaud Lecante
- Institut de Recherche en Infectiologie de Montpellier IRIM - CNRS UMR 9004, Université Montpellier, 34293 Montpellier Cedex 5, France
| | - Valérie Courgnaud
- Institut de Génétique Moléculaire de Montpellier IGMM - CNRS UMR 5535, Université Montpellier, 34293 Montpellier Cedex 5, France.
| | - Jean-Luc Battini
- Institut de Recherche en Infectiologie de Montpellier IRIM - CNRS UMR 9004, Université Montpellier, 34293 Montpellier Cedex 5, France.
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5
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Tang H, Li H, Prakaash D, Pedebos C, Qiu X, Sauer DB, Khalid S, Duerr K, Robinson CV. The solute carrier SPNS2 recruits PI(4,5)P 2 to synergistically regulate transport of sphingosine-1-phosphate. Mol Cell 2023; 83:2739-2752.e5. [PMID: 37499662 PMCID: PMC10790328 DOI: 10.1016/j.molcel.2023.06.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 05/11/2023] [Accepted: 06/26/2023] [Indexed: 07/29/2023]
Abstract
Solute carrier spinster homolog 2 (SPNS2), one of only four known major facilitator superfamily (MFS) lysolipid transporters in humans, exports sphingosine-1-phosphate (S1P) across cell membranes. Here, we explore the synergistic effects of lipid binding and conformational dynamics on SPNS2's transport mechanism. Using mass spectrometry, we discovered that SPNS2 interacts preferentially with PI(4,5)P2. Together with functional studies and molecular dynamics (MD) simulations, we identified potential PI(4,5)P2 binding sites. Mutagenesis of proposed lipid binding sites and inhibition of PI(4,5)P2 synthesis reduce S1P transport, whereas the absence of the N terminus renders the transporter essentially inactive. Probing the conformational dynamics of SPNS2, we show how synergistic binding of PI(4,5)P2 and S1P facilitates transport, increases dynamics of the extracellular gate, and stabilizes the intracellular gate. Given that SPNS2 transports a key signaling lipid, our results have implications for therapeutic targeting and also illustrate a regulatory mechanism for MFS transporters.
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Affiliation(s)
- Haiping Tang
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK; Kavli Institute for Nanoscience Discovery, Oxford OX1 3QU, UK
| | - Huanyu Li
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | - Dheeraj Prakaash
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Conrado Pedebos
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Xingyu Qiu
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK; Kavli Institute for Nanoscience Discovery, Oxford OX1 3QU, UK
| | - David B Sauer
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7DQ, UK
| | - Syma Khalid
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Katharina Duerr
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7DQ, UK; OMass Therapeutics, Ltd., Oxford OX4 2GX, UK
| | - Carol V Robinson
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK; Kavli Institute for Nanoscience Discovery, Oxford OX1 3QU, UK.
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6
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Anagnostakis F, Kokkorakis M, Markouli M, Piperi C. Impact of Solute Carrier Transporters in Glioma Pathology: A Comprehensive Review. Int J Mol Sci 2023; 24:ijms24119393. [PMID: 37298344 DOI: 10.3390/ijms24119393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
Solute carriers (SLCs) are essential for brain physiology and homeostasis due to their role in transporting necessary substances across cell membranes. There is an increasing need to further unravel their pathophysiological implications since they have been proposed to play a pivotal role in brain tumor development, progression, and the formation of the tumor microenvironment (TME) through the upregulation and downregulation of various amino acid transporters. Due to their implication in malignancy and tumor progression, SLCs are currently positioned at the center of novel pharmacological targeting strategies and drug development. In this review, we discuss the key structural and functional characteristics of the main SLC family members involved in glioma pathogenesis, along with their potential targeting options to provide new opportunities for CNS drug design and more effective glioma management.
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Affiliation(s)
- Filippos Anagnostakis
- Department of Medical and Surgical Sciences, University of Bologna, 40126 Bologna, Italy
| | - Michail Kokkorakis
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
| | - Mariam Markouli
- Department of Medicine, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Christina Piperi
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
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7
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Balıkçı E, Marques ASMC, Hansen JS, Huber KVM. Open resources for chemical probes and their implications for future drug discovery. Expert Opin Drug Discov 2023; 18:505-513. [PMID: 37062930 DOI: 10.1080/17460441.2023.2199979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
INTRODUCTION The rational development of new therapeutics requires a thorough understanding of how aberrant signalling affects cellular homeostasis and causes human disease. Chemical probes are tool compounds with well-defined mechanism-of-action enabling modulation of, for example, domain-specific protein properties in a temporal manner, thereby complementing other target validation methods such as genetic gain- and loss-of-function approaches. AREAS COVERED In this review, the authors summarize recent advances in chemical probe development for emerging target classes such as solute carriers and ubiquitin-related targets and highlight open resources to inform and facilitate chemical probe discovery as well as tool compound selection for target validation and phenotypic screening. EXPERT OPINION Chemical probes are powerful tools for drug discovery that have led to fundamental insights into biological processes and have paved the way for the development of first-in-class drugs. Open resources can inform on various aspects of chemical probe development and provide access to data and recommendations on use of chemical probes to catalyse collaborative science and help accelerate drug target identification and validation.
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Affiliation(s)
- Esra Balıkçı
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Anne-Sophie M C Marques
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Jesper S Hansen
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Kilian V M Huber
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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8
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Yan C, Hu X, Liu X, Zhao J, Le Z, Feng J, Zhou M, Ma X, Zheng Q, Sun J. Upregulation of SLC12A3 and SLC12A9 Mediated by the HCP5/miR-140-5p Axis Confers Aggressiveness and Unfavorable Prognosis in Uveal Melanoma. J Transl Med 2023; 103:100022. [PMID: 36925204 DOI: 10.1016/j.labinv.2022.100022] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 10/09/2022] [Accepted: 10/21/2022] [Indexed: 01/11/2023] Open
Abstract
Perturbation of solute carriers (SLCs) has been implicated in metabolic disorders and cancer, highlighting the potential for drug discovery and therapeutic opportunities. However, there is relatively little exploration of the clinical relevance and potential molecular mechanisms underlying the role of the SLC12 family in uveal melanoma (UVM). Here, we performed an integrative multiomics analysis of the SLC12 family in multicenter UVM datasets and found that high expression of SLC12A3 and SLC12A9 was associated with unfavorable prognosis. Moreover, SLC12A3 and SLC12A9 were highly expressed in UVM in vivo. We experimentally characterized the roles of these proteins in tumorigenesis in vitro and explored their association with the prognosis of UVM. Lastly, we identified the HCP5-miR-140-5p axis as a potential noncoding RNA pathway upstream of SLC12A3 and SLC12A9, which was associated with immunomodulation and may represent a novel predictor for clinical prognosis and responsiveness to checkpoint blockade immunotherapy. These findings may facilitate a better understanding of the SLCome and guide future rationalized development of SLC-targeted therapy and drug discovery for UVM.
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Affiliation(s)
- Congcong Yan
- School of Ophthalmology & Optometry and Eye Hospital, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, China
| | - Xiaojuan Hu
- School of Ophthalmology & Optometry and Eye Hospital, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, China
| | - Xiaoyan Liu
- School of Ophthalmology & Optometry and Eye Hospital, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, China
| | - Jingting Zhao
- School of Ophthalmology & Optometry and Eye Hospital, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, China
| | - Zhenmin Le
- School of Ophthalmology & Optometry and Eye Hospital, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, China
| | - Jiayao Feng
- The Affiliated Ningbo Eye Hospital of Wenzhou Medical University, Ningbo, China
| | - Meng Zhou
- School of Ophthalmology & Optometry and Eye Hospital, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, China; Institute of PSI Genomics, Wenzhou, China
| | - Xiaoyin Ma
- School of Ophthalmology & Optometry and Eye Hospital, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, China.
| | - Qingxiang Zheng
- The Affiliated Ningbo Eye Hospital of Wenzhou Medical University, Ningbo, China.
| | - Jie Sun
- School of Ophthalmology & Optometry and Eye Hospital, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, China.
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9
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Abstract
Mast cells are evolutionarily old cells and the principal effectors in allergic responses and inflammation. They are seeded from the yolk sac during embryogenesis or are derived from hematopoietic progenitors and are therefore related to other leukocyte subsets, even though they form a separate clade in the hematopoietic system. Herein, we systematically bundle information from several recent high-throughput endeavors, especially those comparing MCs with other cell types, and combine such information with knowledge on the genes’ functions to reveal groups of neuronal markers specifically expressed by MCs. We focus on recent advances made regarding human tissue MCs, but also refer to studies in mice. In broad terms, genes hyper-expressed in MCs, but largely inactive in other myelocytes, can be classified into subcategories such as traffic/lysosomes (MLPH and RAB27B), the dopamine system (MAOB, DRD2, SLC6A3, and SLC18A2), Ca2+-related entities (CALB2), adhesion molecules (L1CAM and NTM) and, as an overall principle, the transcription factors and modulators of transcriptional activity (LMO4, PBX1, MEIS2, and EHMT2). Their function in MCs is generally unknown but may tentatively be deduced by comparison with other systems. MCs share functions with the nervous system, as they express typical neurotransmitters (histamine and serotonin) and a degranulation machinery that shares features with the neuronal apparatus at the synapse. Therefore, selective overlaps are plausible, and they further highlight the uniqueness of MCs within the myeloid system, as well as when compared with basophils. Apart from investigating their functional implications in MCs, a key question is whether their expression in the lineage is due to the specific reactivation of genes normally silenced in leukocytes or whether the genes are not switched off during mastocytic development from early progenitors.
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Affiliation(s)
- Magda Babina
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute of Allergology, Hindenburgdamm 30, 12203 Berlin, Germany
- Correspondence:
| | - Kristin Franke
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute of Allergology, Hindenburgdamm 30, 12203 Berlin, Germany
| | - Gürkan Bal
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute of Allergology, Hindenburgdamm 30, 12203 Berlin, Germany
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10
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Schicker K, Farr CV, Boytsov D, Freissmuth M, Sandtner W. Optimizing the Substrate Uptake Rate of Solute Carriers. Front Physiol 2022; 13:817886. [PMID: 35185619 PMCID: PMC8850955 DOI: 10.3389/fphys.2022.817886] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 01/10/2022] [Indexed: 11/16/2022] Open
Abstract
The diversity in solute carriers arose from evolutionary pressure. Here, we surmised that the adaptive search for optimizing the rate of substrate translocation was also shaped by the ambient extracellular and intracellular concentrations of substrate and co-substrate(s). We explored possible solutions by employing kinetic models, which were based on analytical expressions of the substrate uptake rate, that is, as a function of the microscopic rate constants used to parameterize the transport cycle. We obtained the defining terms for five reaction schemes with identical transport stoichiometry (i.e., Na+: substrate = 2:1). We then utilized an optimization algorithm to find the set of numeric values for the microscopic rate constants, which provided the largest value for the substrate uptake rate: The same optimized rate was achieved by different sets of numerical values for the microscopic rate constants. An in-depth analysis of these sets provided the following insights: (i) In the presence of a low extracellular substrate concentration, a transporter can only cycle at a high rate, if it has low values for both, the Michaelis-Menten constant (KM) for substrate and the maximal substrate uptake rate (Vmax). (ii) The opposite is true for a transporter operating at high extracellular substrate concentrations. (iii) Random order of substrate and co-substrate binding is superior to sequential order, if a transporter is to maintain a high rate of substrate uptake in the presence of accumulating intracellular substrate. Our kinetic models provide a framework to understand how and why the transport cycles of closely related transporters differ.
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Affiliation(s)
| | | | | | | | - Walter Sandtner
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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11
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Uddin ME, Moseley A, Hu S, Sparreboom A. Contribution of membrane transporters to chemotherapy-induced cardiotoxicity. Basic Clin Pharmacol Toxicol 2022; 130 Suppl 1:36-47. [PMID: 34237188 DOI: 10.1111/bcpt.13635] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/30/2021] [Accepted: 07/06/2021] [Indexed: 11/27/2022]
Abstract
Membrane transporters play a key role in determining the pharmacokinetic profile, therapeutic safety, and efficacy of many chemotherapeutic drugs by regulating cellular influx and efflux. Rapidly emerging evidence has shown that tissue-specific expression of transporters contributes to local drug accumulation and drug-drug interactions and that functional alterations in these transporters can directly influence an individual's susceptibility to drug-induced toxicity. Comprehending the complex mechanism of transporter function in regulating drug distribution in tissues, such as the heart, is necessary in order to acquire novel therapeutic strategies aimed at evading unwanted drug accumulation and toxicities and to ameliorate the safety of current therapeutic regimens. Here, we provide an overview of membrane transporters with a role in chemotherapy-induced cardiotoxicity and discuss novel strategies to improve therapeutic outcomes.
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Affiliation(s)
- Muhammad Erfan Uddin
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
| | - Angie Moseley
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
| | - Shuiying Hu
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
| | - Alex Sparreboom
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
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12
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Holzhüter K, Geertsma ER. Uniport, Not Proton-Symport, in a Non-Mammalian SLC23 Transporter. J Mol Biol 2021; 434:167393. [PMID: 34896363 DOI: 10.1016/j.jmb.2021.167393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/17/2021] [Accepted: 12/01/2021] [Indexed: 10/25/2022]
Abstract
SLC23 family members are transporters of either nucleobases or ascorbate. While the mammalian SLC23 ascorbate transporters are sodium-coupled, the non-mammalian nucleobase transporters have been proposed, but not formally shown, to be proton-coupled symporters. This assignment is exclusively based on in vivo transport assays using protonophores. Here, by establishing the first in vitro transport assay for this protein family, we demonstrate that a representative member of the SLC23 nucleobase transporters operates as a uniporter instead. We explain these conflicting assignments by identifying a critical role of uracil phosphoribosyltransferase, the enzyme converting uracil to UMP, in driving uracil uptake in vivo. Detailed characterization of uracil phosphoribosyltransferase reveals that the sharp reduction of uracil uptake in whole cells in presence of protonophores is caused by acidification-induced enzyme inactivation. The SLC23 family therefore consists of both uniporters and symporters in line with the structurally related SLC4 and SLC26 families that have previously been demonstrated to accommodate both transport modes as well.
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Affiliation(s)
- Katharina Holzhüter
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany
| | - Eric R Geertsma
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany; Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany.
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13
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Huang KM, Zavorka Thomas M, Magdy T, Eisenmann ED, Uddin ME, DiGiacomo DF, Pan A, Keiser M, Otter M, Xia SH, Li Y, Jin Y, Fu Q, Gibson AA, Bonilla IM, Carnes CA, Corps KN, Coppola V, Smith SA, Addison D, Nies AT, Bundschuh R, Chen T, Lustberg MB, Wang J, Oswald S, Campbell MJ, Yan PS, Baker SD, Hu S, Burridge PW, Sparreboom A. Targeting OCT3 attenuates doxorubicin-induced cardiac injury. Proc Natl Acad Sci U S A 2021; 118:e2020168118. [PMID: 33495337 DOI: 10.1073/pnas.2020168118] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Doxorubicin is a commonly used anticancer agent that can cause debilitating and irreversible cardiac injury. The initiating mechanisms contributing to this side effect remain unknown, and current preventative strategies offer only modest protection. Using stem-cell-derived cardiomyocytes from patients receiving doxorubicin, we probed the transcriptomic landscape of solute carriers and identified organic cation transporter 3 (OCT3) (SLC22A3) as a critical transporter regulating the cardiac accumulation of doxorubicin. Functional validation studies in heterologous overexpression models confirmed that doxorubicin is transported into cardiomyocytes by OCT3 and that deficiency of OCT3 protected mice from acute and chronic doxorubicin-related changes in cardiovascular function and genetic pathways associated with cardiac damage. To provide proof-of-principle and demonstrate translational relevance of this transport mechanism, we identified several pharmacological inhibitors of OCT3, including nilotinib, and found that pharmacological targeting of OCT3 can also preserve cardiovascular function following treatment with doxorubicin without affecting its plasma levels or antitumor effects in multiple models of leukemia and breast cancer. Finally, we identified a previously unrecognized, OCT3-dependent pathway of doxorubicin-induced cardiotoxicity that results in a downstream signaling cascade involving the calcium-binding proteins S100A8 and S100A9. These collective findings not only shed light on the etiology of doxorubicin-induced cardiotoxicity, but also are of potential translational relevance and provide a rationale for the implementation of a targeted intervention strategy to prevent this debilitating side effect.
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14
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Kandasamy P, Zlobec I, Nydegger DT, Pujol-Giménez J, Bhardwaj R, Shirasawa S, Tsunoda T, Hediger MA. Oncogenic KRAS mutations enhance amino acid uptake by colorectal cancer cells via the hippo signaling effector YAP1. Mol Oncol 2021; 15:2782-2800. [PMID: 34003553 PMCID: PMC8486573 DOI: 10.1002/1878-0261.12999] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/14/2021] [Accepted: 05/14/2021] [Indexed: 12/28/2022] Open
Abstract
Oncogenic KRAS mutations develop unique metabolic dependencies on nutrients to support tumor metabolism and cell proliferation. In particular, KRAS mutant cancer cells exploit amino acids (AAs) such as glutamine and leucine, to accelerate energy metabolism, redox balance through glutathione synthesis and macromolecule biosynthesis. However, the identities of the amino acid transporters (AATs) that are prominently upregulated in KRAS mutant cancer cells, and the mechanism regulating their expression have not yet been systematically investigated. Here, we report that the majority of the KRAS mutant colorectal cancer (CRC) cells upregulate selected AATs (SLC7A5/LAT1, SLC38A2/SNAT2, and SLC1A5/ASCT2), which correlates with enhanced uptake of AAs such as glutamine and leucine. Consistently, knockdown of oncogenic KRAS downregulated the expression of AATs, thereby decreasing the levels of amino acids taken up by CRC cells. Moreover, overexpression of mutant KRAS upregulated the expression of AATs (SLC7A5/LAT1, SLC38A2/SNAT2, and SLC1A5/ASCT2) in KRAS wild-type CRC cells and mouse embryonic fibroblasts. In addition, we show that the YAP1 (Yes-associated protein 1) transcriptional coactivator accounts for increased expression of AATs and mTOR activation in KRAS mutant CRC cells. Specific knockdown of AATs by shRNAs or pharmacological blockage of AATs effectively inhibited AA uptake, mTOR activation, and cell proliferation. Collectively, we conclude that oncogenic KRAS mutations enhance the expression of AATs via the hippo effector YAP1, leading to mTOR activation and CRC cell proliferation.
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Affiliation(s)
- Palanivel Kandasamy
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, Inselspital, University of Bern, Switzerland.,Department of Biomedical Research, University of Bern, Switzerland
| | - Inti Zlobec
- Translational Research Unit (TRU), Institute of Pathology, University of Bern, Switzerland
| | - Damian T Nydegger
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, Inselspital, University of Bern, Switzerland.,Department of Biomedical Research, University of Bern, Switzerland
| | - Jonai Pujol-Giménez
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, Inselspital, University of Bern, Switzerland.,Department of Biomedical Research, University of Bern, Switzerland
| | - Rajesh Bhardwaj
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, Inselspital, University of Bern, Switzerland.,Department of Biomedical Research, University of Bern, Switzerland
| | - Senji Shirasawa
- Department of Cell Biology, Faculty of Medicine, Fukuoka University, Japan
| | - Toshiyuki Tsunoda
- Department of Cell Biology, Faculty of Medicine, Fukuoka University, Japan
| | - Matthias A Hediger
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, Inselspital, University of Bern, Switzerland.,Department of Biomedical Research, University of Bern, Switzerland
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15
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Hewton KG, Johal AS, Parker SJ. Transporters at the Interface between Cytosolic and Mitochondrial Amino Acid Metabolism. Metabolites 2021; 11:metabo11020112. [PMID: 33669382 PMCID: PMC7920303 DOI: 10.3390/metabo11020112] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/07/2021] [Accepted: 02/12/2021] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are central organelles that coordinate a vast array of metabolic and biologic functions important for cellular health. Amino acids are intricately linked to the bioenergetic, biosynthetic, and homeostatic function of the mitochondrion and require specific transporters to facilitate their import, export, and exchange across the inner mitochondrial membrane. Here we review key cellular metabolic outputs of eukaryotic mitochondrial amino acid metabolism and discuss both known and unknown transporters involved. Furthermore, we discuss how utilization of compartmentalized amino acid metabolism functions in disease and physiological contexts. We examine how improved methods to study mitochondrial metabolism, define organelle metabolite composition, and visualize cellular gradients allow for a more comprehensive understanding of how transporters facilitate compartmentalized metabolism.
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Affiliation(s)
- Keeley G. Hewton
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (K.G.H.); (A.S.J.)
| | - Amritpal S. Johal
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (K.G.H.); (A.S.J.)
| | - Seth J. Parker
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (K.G.H.); (A.S.J.)
- British Columbia Children’s Hospital Research Institute, Vancouver, BC V6H 0B3, Canada
- Correspondence: ; Tel.: +1-604-875-3121
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16
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Abstract
Introduction: Solute Carrier (SLC) and ATP-binding cassette (ABC) transporters expressed in the intestine, liver, and kidney determine the absorption, distribution, and excretion of drugs. In addition, most molecular and cellular processes show circadian rhythmicity controlled by circadian clocks that leads to diurnal variations in the pharmacokinetics and pharmacodynamics of many drugs and affects their therapeutic efficacy and toxicity.Area covered: This review provides an overview of the current knowledge on the circadian rhythmicity of drug transporters and the molecular mechanisms of their circadian control. Evidence for coupling drug transporters to circadian oscillators and the plausible candidates conveying circadian clock signals to target drug transporters, particularly transcription factors operating as the output of clock genes, is discussed.Expert opinion: The circadian machinery has been demonstrated to interact with the uptake and efflux of various drug transporters. The evidence supports the concept that diurnal changes that affect drug transporters may influence the pharmacokinetics of the drugs. However, more systematic studies are required to better define the timing of pharmacologically important drug transporter regulation and determine tissue- and sex-dependent differences. Finally, the transfer of knowledge based on the results and conclusions obtained primarily from animal models will require careful validation before it is applied to humans.
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Affiliation(s)
- Jiří Pácha
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Kateřina Balounová
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic.,Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Matúš Soták
- Department of Molecular and Clinical Medicine, Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.,Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
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17
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Huang KM, Hu S. Targeting drug transporters to prevent chemotherapy-induced peripheral neuropathy. Mol Cell Oncol 2020; 8:1838863. [PMID: 33553600 PMCID: PMC7849748 DOI: 10.1080/23723556.2020.1838863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 10/10/2020] [Accepted: 10/13/2020] [Indexed: 06/12/2023]
Abstract
Chemotherapy-induced peripheral neuropathy is a debilitating toxicity that adversely affects patient quality and course of treatment. Recent findings have demonstrated that the etiology of peripheral neuropathy is dependent on transporter-mediated accumulation in dorsal root ganglia, and targeting this mechanism can afford neurological protection without compromising therapeutic efficacy.
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Affiliation(s)
- Kevin M. Huang
- Department of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
| | - Shuiying Hu
- Department of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
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18
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Colas C, Laine E. Targeting Solute Carrier Transporters through Functional Mapping. Trends Pharmacol Sci 2020; 42:3-6. [PMID: 33234336 DOI: 10.1016/j.tips.2020.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 10/12/2020] [Accepted: 11/02/2020] [Indexed: 10/22/2022]
Abstract
Solute carrier (SLC) transporters are emerging drug targets. Identifying the molecular determinants responsible for their specific and selective transport activities and describing key interactions with their ligands are crucial steps towards the design of potential new drugs. A general functional mapping across more than 400 human SLC transporters would pave the way to the rational and systematic design of molecules modulating cellular transport.
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Affiliation(s)
- Claire Colas
- Department of Pharmaceutical Chemistry, University of Vienna, Althanstrasse 14, 1090, Wien, Austria.
| | - Elodie Laine
- Sorbonne Université, UPMC University Paris 06, CNRS, IBPS, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France
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19
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Abstract
Metabolism reprogramming is critical for both cancer progression and effective immune responses in the tumor microenvironment. Amino acid metabolism in different cells and their cross-talk shape tumor immunity and therapy efficacy in patients with cancer. In this review, we focus on multiple amino acids and their transporters, solute carrier (SLC) members. We discuss their involvement in regulation of immune responses in the tumor microenvironment and assess their associations with cancer immunotherapy, chemotherapy, and radiation therapy, and we review their potential as targets for cancer therapy. We stress the necessity to understand individual amino acids and their transporters in different cell subsets, the molecular intersection between amino acid metabolism, and effective T cell immunity and its relevance in cancer therapies.
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Affiliation(s)
- Weimin Wang
- Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA.
| | - Weiping Zou
- Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA; Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Graduate Program in Immunology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA; Graduate Program in Cancer Biology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA.
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20
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Colas C. Toward a Systematic Structural and Functional Annotation of Solute Carriers Transporters-Example of the SLC6 and SLC7 Families. Front Pharmacol 2020; 11:1229. [PMID: 32973497 PMCID: PMC7466448 DOI: 10.3389/fphar.2020.01229] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/28/2020] [Indexed: 12/12/2022] Open
Abstract
SLC transporters are emerging key drug targets. One important step for drug development is the profound understanding of the structural determinants defining the substrate selectivity of each transporter. Recently, the improvement of computational power and experimental methods such as X-ray and cryo-EM crystallography permitted to conduct structure-based studies on specific transporters having important pharmacological impact. However, a lot remains to be discovered regarding their dynamics, transport modulation and ligand recognition. A detailed functional characterization of transporters would provide opportunities to develop new compounds targeting these key drug targets. Here, we are giving an overview of two major human LeuT-fold families, SLC6 and SLC7, with an emphasis on the most relevant members of each family for drug development. We gather the most recent understanding on the structural determinants of selectivity within and across the two families. We then use this information to discuss the benefits of a more generalized structural and functional annotation of the LeuT fold and the implications of such mapping for drug discovery.
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Affiliation(s)
- Claire Colas
- University of Vienna, Department of Pharmaceutical Chemistry, Vienna, Austria
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21
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Ceder MM, Lekholm E, Klaesson A, Tripathi R, Schweizer N, Weldai L, Patil S, Fredriksson R. Glucose Availability Alters Gene and Protein Expression of Several Newly Classified and Putative Solute Carriers in Mice Cortex Cell Culture and D. melanogaster. Front Cell Dev Biol 2020; 8:579. [PMID: 32733888 PMCID: PMC7358622 DOI: 10.3389/fcell.2020.00579] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/15/2020] [Indexed: 12/16/2022] Open
Abstract
Many newly identified solute carriers (SLCs) and putative transporters have the possibility to be intricately involved in glucose metabolism. Here we show that many transporters of this type display a high degree of regulation at both mRNA and protein level following no or low glucose availability in mouse cortex cultures. We show that this is also the case in Drosophila melanogaster subjected to starvation or diets with different sugar content. Interestingly, re-introduction of glucose to media, or refeeding flies, normalized the gene expression of a number of the targets, indicating a fast and highly dynamic control. Our findings demonstrate high conservation of these transporters and how dependent both cell cultures and organisms are on gene and protein regulation during metabolic fluctuations. Several transporter genes were regulated simultaneously maybe to initiate alternative metabolic pathways as a response to low glucose levels, both in the cell cultures and in D. melanogaster. Our results display that newly identified SLCs of Major Facilitator Superfamily type, as well as the putative transporters included in our study, are regulated by glucose availability and could be involved in several cellular aspects dependent of glucose and/or its metabolites. Recently, a correlation between dysregulation of glucose in the central nervous system and numerous diseases such as obesity, type 2 diabetes mellitus as well as neurological disease such as Alzheimer’s and Parkinson’s diseases indicate a complex regulation and fine tuning of glucose levels in the brain. The fact that almost one third of transporters and transporter-related proteins remain orphans with unknown or contradictive substrate profile, location and function, pinpoint the need for further research about them to fully understand their mechanistic role and their impact on cellular metabolism.
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Affiliation(s)
- Mikaela M Ceder
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Emilia Lekholm
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Axel Klaesson
- Pharmaceutical Cell Biology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Rekha Tripathi
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Nadine Schweizer
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Lydia Weldai
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Sourabh Patil
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Robert Fredriksson
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
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22
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Meixner E, Goldmann U, Sedlyarov V, Scorzoni S, Rebsamen M, Girardi E, Superti‐Furga G. A substrate-based ontology for human solute carriers. Mol Syst Biol 2020; 16:e9652. [PMID: 32697042 PMCID: PMC7374931 DOI: 10.15252/msb.20209652] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/24/2020] [Accepted: 06/26/2020] [Indexed: 11/09/2022] Open
Abstract
Solute carriers (SLCs) are the largest family of transmembrane transporters in the human genome with more than 400 members. Despite the fact that SLCs mediate critical biological functions and several are important pharmacological targets, a large proportion of them is poorly characterized and present no assigned substrate. A major limitation to systems-level de-orphanization campaigns is the absence of a structured, language-controlled chemical annotation. Here we describe a thorough manual annotation of SLCs based on literature. The annotation of substrates, transport mechanism, coupled ions, and subcellular localization for 446 human SLCs confirmed that ~30% of these were still functionally orphan and lacked known substrates. Application of a substrate-based ontology to transcriptomic datasets identified SLC-specific responses to external perturbations, while a machine-learning approach based on the annotation allowed us to identify potential substrates for several orphan SLCs. The annotation is available at https://opendata.cemm.at/gsflab/slcontology/. Given the increasing availability of large biological datasets and the growing interest in transporters, we expect that the effort presented here will be critical to provide novel insights into the functions of SLCs.
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Affiliation(s)
- Eva Meixner
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Ulrich Goldmann
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Vitaly Sedlyarov
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Stefania Scorzoni
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Manuele Rebsamen
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Enrico Girardi
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Giulio Superti‐Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
- Center for Physiology and PharmacologyMedical University of ViennaViennaAustria
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23
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Huang KM, Uddin ME, DiGiacomo D, Lustberg MB, Hu S, Sparreboom A. Role of SLC transporters in toxicity induced by anticancer drugs. Expert Opin Drug Metab Toxicol 2020; 16:493-506. [PMID: 32276560 DOI: 10.1080/17425255.2020.1755253] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION . Membrane transporters are integral to the maintenance of cellular integrity of all tissue and cell types. While transporters play an established role in the systemic pharmacokinetics of therapeutic drugs, tissue specific expression of uptake transporters can serve as an initiating mechanism that governs the accumulation and impact of cytotoxic drugs. AREAS COVERED . This review provides an overview of organic cation transporters as determinants of chemotherapy-induced toxicities. We also provide insights into the recently updated FDA guidelines for in vitro drug interaction studies, with a particular focus on the class of tyrosine kinase inhibitors as perpetrators of transporter-mediated drug interactions. EXPERT OPINION . Studies performed over the last few decades have highlighted the important role of basolateral uptake and apical efflux transporters in the pathophysiology of drug-induced organ damage. Increased understanding of the mechanisms that govern the accumulation of cytotoxic drugs has provided insights into the development of novel strategies to prevent debilitating toxicities. Furthermore, we argue that current regulatory guidelines provide inadequate recommendations for in vitro studies to identify substrates or inhibitors of drug transporters. Therefore, the translational and predictive power of FDA-approved drugs as modulators of transport function remains ambiguous and warrants further revision of the current guidelines.
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Affiliation(s)
- Kevin M Huang
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, the Ohio State University , Columbus, OH, USA
| | - Muhammad Erfan Uddin
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, the Ohio State University , Columbus, OH, USA
| | - Duncan DiGiacomo
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, the Ohio State University , Columbus, OH, USA
| | - Maryam B Lustberg
- Department of Medical Oncology, College of Medicine, the Ohio State University and Comprehensive Cancer Center , Columbus, OH, USA
| | - Shuiying Hu
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, the Ohio State University , Columbus, OH, USA
| | - Alex Sparreboom
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, the Ohio State University , Columbus, OH, USA
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24
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Chaves C, Campanelli F, Chapy H, Gomez-Zepeda D, Glacial F, Smirnova M, Taghi M, Pallud J, Perrière N, Declèves X, Menet MC, Cisternino S. An Interspecies Molecular and Functional Study of Organic Cation Transporters at the Blood-Brain Barrier: From Rodents to Humans. Pharmaceutics 2020; 12:pharmaceutics12040308. [PMID: 32231079 PMCID: PMC7238036 DOI: 10.3390/pharmaceutics12040308] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/16/2020] [Accepted: 03/25/2020] [Indexed: 01/11/2023] Open
Abstract
Organic cation transporters (OCTs) participate in the handling of compounds in kidneys and at the synaptic cleft. Their role at the blood-brain barrier (BBB) in brain drug delivery is still unclear. The presence of OCT1,2,3 (SLC22A1-3) in mouse, rat and human isolated brain microvessels was investigated by either qRT-PCR, quantitative proteomics and/or functional studies. BBB transport of the prototypical substrate [3H]-1-methyl-4-phenylpyridinium ([3H]-MPP+) was measured by in situ brain perfusion in six mouse strains and in Sprague Dawley rats, in primary human brain microvascular endothelial cells seeded on inserts, in the presence or absence of OCTs and a MATE1 (SLC49A1) inhibitor. The results show negligible OCT1 (SLC22A1) and OCT2 (SLC22A2) expression in either mice, rat or human brain microvessels, while OCT3 expression was identified in rat microvessels by qRT-PCR. The in vitro human cellular uptake of [3H]-MPP+ was not modified by OCTs/MATE-inhibitor. Brain transport of [3H]-MPP+ remains unchanged between 2- and 6-month old mice, and no alteration was observed in mice and rats with inhibitors. In conclusion, the evidenced lack of expression and/or functional OCTs and MATE at the BBB allows the maintenance of the brain homeostasis and function as it prevents an easy access of their neurotoxicant substrates to the brain parenchyma.
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Affiliation(s)
- Catarina Chaves
- Inserm, U1144, Optimisation Thérapeutique en Neuropsychopharmacologie, 75006 Paris, France; (C.C.); (F.C.); (H.C.); (M.S.); (M.T.); (X.D.); (M.-C.M.)
- Faculté de pharmacie, Université de Paris, UMR-S 1144, 4, Avenue de l’Observatoire, 75006 Paris, France
| | - Federica Campanelli
- Inserm, U1144, Optimisation Thérapeutique en Neuropsychopharmacologie, 75006 Paris, France; (C.C.); (F.C.); (H.C.); (M.S.); (M.T.); (X.D.); (M.-C.M.)
- Faculté de pharmacie, Université de Paris, UMR-S 1144, 4, Avenue de l’Observatoire, 75006 Paris, France
| | - Hélène Chapy
- Inserm, U1144, Optimisation Thérapeutique en Neuropsychopharmacologie, 75006 Paris, France; (C.C.); (F.C.); (H.C.); (M.S.); (M.T.); (X.D.); (M.-C.M.)
- Faculté de pharmacie, Université de Paris, UMR-S 1144, 4, Avenue de l’Observatoire, 75006 Paris, France
| | - David Gomez-Zepeda
- Inserm, U1144, Optimisation Thérapeutique en Neuropsychopharmacologie, 75006 Paris, France; (C.C.); (F.C.); (H.C.); (M.S.); (M.T.); (X.D.); (M.-C.M.)
- Faculté de pharmacie, Université de Paris, UMR-S 1144, 4, Avenue de l’Observatoire, 75006 Paris, France
| | - Fabienne Glacial
- BrainPlotting SAS, Institut du Cerveau et de la Moelle épinière, 75013 Paris, France; (F.G.); (N.P.)
| | - Maria Smirnova
- Inserm, U1144, Optimisation Thérapeutique en Neuropsychopharmacologie, 75006 Paris, France; (C.C.); (F.C.); (H.C.); (M.S.); (M.T.); (X.D.); (M.-C.M.)
- Faculté de pharmacie, Université de Paris, UMR-S 1144, 4, Avenue de l’Observatoire, 75006 Paris, France
| | - Meryam Taghi
- Inserm, U1144, Optimisation Thérapeutique en Neuropsychopharmacologie, 75006 Paris, France; (C.C.); (F.C.); (H.C.); (M.S.); (M.T.); (X.D.); (M.-C.M.)
- Faculté de pharmacie, Université de Paris, UMR-S 1144, 4, Avenue de l’Observatoire, 75006 Paris, France
| | - Johan Pallud
- Department of Neurosurgery, Sainte Anne Hospital, 75014 Paris, France;
- Inserm, U894, IMA-Brain, Centre de Psychiatrie et Neurosciences, 75013 Paris, France
| | - Nicolas Perrière
- BrainPlotting SAS, Institut du Cerveau et de la Moelle épinière, 75013 Paris, France; (F.G.); (N.P.)
| | - Xavier Declèves
- Inserm, U1144, Optimisation Thérapeutique en Neuropsychopharmacologie, 75006 Paris, France; (C.C.); (F.C.); (H.C.); (M.S.); (M.T.); (X.D.); (M.-C.M.)
- Faculté de pharmacie, Université de Paris, UMR-S 1144, 4, Avenue de l’Observatoire, 75006 Paris, France
- Assistance Publique-Hôpitaux de Paris, AP-HP, Hôpital Universitaire Cochin, Biologie du médicament et toxicologie, 75006 Paris, France
| | - Marie-Claude Menet
- Inserm, U1144, Optimisation Thérapeutique en Neuropsychopharmacologie, 75006 Paris, France; (C.C.); (F.C.); (H.C.); (M.S.); (M.T.); (X.D.); (M.-C.M.)
- Faculté de pharmacie, Université de Paris, UMR-S 1144, 4, Avenue de l’Observatoire, 75006 Paris, France
- Assistance Publique-Hôpitaux de Paris, AP-HP, Hôpital Universitaire Cochin, Hormonologie adulte, 75006 Paris, France
| | - Salvatore Cisternino
- Inserm, U1144, Optimisation Thérapeutique en Neuropsychopharmacologie, 75006 Paris, France; (C.C.); (F.C.); (H.C.); (M.S.); (M.T.); (X.D.); (M.-C.M.)
- Faculté de pharmacie, Université de Paris, UMR-S 1144, 4, Avenue de l’Observatoire, 75006 Paris, France
- Assistance Publique-Hôpitaux de Paris, AP-HP, Hôpital Universitaire Necker-Enfants Malades, Service de pharmacie, 75015 Paris, France
- Correspondence: ; Tel.: +33-1-444-951-91
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25
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Yahyaoui R, Pérez-Frías J. Amino Acid Transport Defects in Human Inherited Metabolic Disorders. Int J Mol Sci 2019; 21:ijms21010119. [PMID: 31878022 PMCID: PMC6981491 DOI: 10.3390/ijms21010119] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/12/2019] [Accepted: 12/18/2019] [Indexed: 02/07/2023] Open
Abstract
Amino acid transporters play very important roles in nutrient uptake, neurotransmitter recycling, protein synthesis, gene expression, cell redox balance, cell signaling, and regulation of cell volume. With regard to transporters that are closely connected to metabolism, amino acid transporter-associated diseases are linked to metabolic disorders, particularly when they involve different organs, cell types, or cell compartments. To date, 65 different human solute carrier (SLC) families and more than 400 transporter genes have been identified, including 11 that are known to include amino acid transporters. This review intends to summarize and update all the conditions in which a strong association has been found between an amino acid transporter and an inherited metabolic disorder. Many of these inherited disorders have been identified in recent years. In this work, the physiological functions of amino acid transporters will be described by the inherited diseases that arise from transporter impairment. The pathogenesis, clinical phenotype, laboratory findings, diagnosis, genetics, and treatment of these disorders are also briefly described. Appropriate clinical and diagnostic characterization of the underlying molecular defect may give patients the opportunity to avail themselves of appropriate therapeutic options in the future.
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Affiliation(s)
- Raquel Yahyaoui
- Laboratory of Metabolic Disorders and Newborn Screening Center of Eastern Andalusia, Málaga Regional University Hospital, 29011 Málaga, Spain
- Grupo Endocrinología y Nutrición, Diabetes y Obesidad, Instituto de Investigación Biomédica de Málaga-IBIMA, 29010 Málaga, Spain
- Correspondence:
| | - Javier Pérez-Frías
- Grupo Multidisciplinar de Investigación Pediátrica, Instituto de Investigación Biomédica de Málaga-IBIMA, 29010 Málaga, Spain;
- Departamento de Farmacología y Pediatría, Facultad de Medicina, Universidad de Málaga, 29010 Málaga, Spain
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26
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Huang MS, Lin WC, Chang JH, Cheng CH, Wang HY, Mou KY. The cysteine-free single mutant C32S of APEX2 is a highly expressed and active fusion tag for proximity labeling applications. Protein Sci 2019; 28:1703-1712. [PMID: 31306516 DOI: 10.1002/pro.3685] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/09/2019] [Accepted: 07/09/2019] [Indexed: 12/21/2022]
Abstract
APEX2, an engineered ascorbate peroxidase for high activity, is a powerful tool for proximity labeling applications. Owing to its lack of disulfides and the calcium-independent activity, APEX2 can be applied intracellularly for targeted electron microscopy imaging or interactome mapping when fusing to a protein of interest. However, APEX2 fusion is often deleterious to the protein expression, which seriously hampers its wide utility. This problem is especially compelling when APEX2 is fused to structurally delicate proteins, such as multi-pass membrane proteins. In this study, we found that a cysteine-free single mutant C32S of APEX2 dramatically improved the expression of fusion proteins in mammalian cells without compromising the enzyme activity. We fused APEX2 and APEX2C32S to four multi-transmembrane solute carriers (SLCs), SLC1A5, SLC6A5, SLC6A14, and SLC7A1, and compared their expressions in stable HEK293T cell lines. Except the SLC6A5 fusions expressing at decent levels for both APEX2 (70%) and APEX2C32S (73%), other three SLC proteins showed significantly better expression when fusing to APEX2C32S (69 ± 13%) than APEX2 (29 ± 15%). Immunofluorescence and western blot experiments showed correct plasma membrane localization and strong proximity labeling efficiency in all four SLC-APEX2C32S cells. Enzyme kinetic experiments revealed that APEX2 and APEX2C32S have comparable activities in terms of oxidizing guaiacol. Overall, we believe APEX2C32S is a superior fusion tag to APEX2 for proximity labeling applications, especially when mismatched disulfide bonding or poor expression is a concern.
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Affiliation(s)
- Meng-Sen Huang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.,Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Wen-Ching Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Jen-Hsuan Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Cheng-Hung Cheng
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Han Ying Wang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Kurt Yun Mou
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
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27
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Chiduza GN, Johnson RM, Wright GSA, Antonyuk SV, Muench SP, Hasnain SS. LAT1 (SLC7A5) and CD98hc (SLC3A2) complex dynamics revealed by single-particle cryo-EM. Acta Crystallogr D Struct Biol 2019; 75:660-669. [PMID: 31282475 PMCID: PMC7285653 DOI: 10.1107/s2059798319009094] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 06/25/2019] [Indexed: 12/13/2022] Open
Abstract
Solute carriers are a large class of transporters that play key roles in normal and disease physiology. Among the solute carriers, heteromeric amino-acid transporters (HATs) are unique in their quaternary structure. LAT1-CD98hc, a HAT, transports essential amino acids and drugs across the blood-brain barrier and into cancer cells. It is therefore an important target both biologically and therapeutically. During the course of this work, cryo-EM structures of LAT1-CD98hc in the inward-facing conformation and in either the substrate-bound or apo states were reported to 3.3-3.5 Å resolution [Yan et al. (2019), Nature (London), 568, 127-130]. Here, these structures are analyzed together with our lower resolution cryo-EM structure, and multibody 3D auto-refinement against single-particle cryo-EM data was used to characterize the dynamics of the interaction of CD98hc and LAT1. It is shown that the CD98hc ectodomain and the LAT1 extracellular surface share no substantial interface. This allows the CD98hc ectodomain to have a high degree of movement within the extracellular space. The functional implications of these aspects are discussed together with the structure determination.
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Affiliation(s)
- George N. Chiduza
- Molecular Biophysics Group, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, England
| | - Rachel M. Johnson
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, England
| | - Gareth S. A. Wright
- Molecular Biophysics Group, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, England
| | - Svetlana V. Antonyuk
- Molecular Biophysics Group, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, England
| | - Stephen P. Muench
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, England
| | - S. Samar Hasnain
- Molecular Biophysics Group, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, England
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28
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César-Razquin A, Girardi E, Yang M, Brehme M, Saez-Rodriguez J, Superti-Furga G. In silico Prioritization of Transporter-Drug Relationships From Drug Sensitivity Screens. Front Pharmacol 2018; 9:1011. [PMID: 30245630 PMCID: PMC6137680 DOI: 10.3389/fphar.2018.01011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 08/20/2018] [Indexed: 01/28/2023] Open
Abstract
The interplay between drugs and cell metabolism is a key factor in determining both compound potency and toxicity. In particular, how and to what extent transmembrane transporters affect drug uptake and disposition is currently only partially understood. Most transporter proteins belong to two protein families: the ATP-Binding Cassette (ABC) transporter family, whose members are often involved in xenobiotic efflux and drug resistance, and the large and heterogeneous family of solute carriers (SLCs). We recently argued that SLCs are collectively a rather neglected gene group, with most of its members still poorly characterized, and thus likely to include many yet-to-be-discovered associations with drugs. We searched publicly available resources and literature to define the currently known set of drugs transported by ABCs or SLCs, which involved ∼500 drugs and more than 100 transporters. In order to extend this set, we then mined the largest publicly available pharmacogenomics dataset, which involves approximately 1,000 molecularly annotated cancer cell lines and their response to 265 anti-cancer compounds, and used regularized linear regression models (Elastic Net, LASSO) to predict drug responses based on SLC and ABC data (expression levels, SNVs, CNVs). The most predictive models included both known and previously unidentified associations between drugs and transporters. To our knowledge, this represents the first application of regularized linear regression to this set of genes, providing an extensive prioritization of potentially pharmacologically interesting interactions.
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Affiliation(s)
- Adrián César-Razquin
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Enrico Girardi
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Mi Yang
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
- RWTH Aachen University, Faculty of Medicine, Joint Research Centre for Computational Biomedicine (JRC-COMBINE), Aachen, Germany
| | - Marc Brehme
- RWTH Aachen University, Faculty of Medicine, Joint Research Centre for Computational Biomedicine (JRC-COMBINE), Aachen, Germany
- CBmed – Center for Biomarker Research in Medicine GmbH, Graz, Austria
| | - Julio Saez-Rodriguez
- RWTH Aachen University, Faculty of Medicine, Joint Research Centre for Computational Biomedicine (JRC-COMBINE), Aachen, Germany
- European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge, United Kingdom
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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29
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Abstract
Neurosteroids, comprising pregnane, androstane, and sulfated steroids can alter neuronal excitability through interaction with ligand-gated ion channels and other receptors and have therefore a therapeutic potential in several brain disorders. They can be formed in brain cells or are synthesized by an endocrine gland and reach the brain by penetrating the blood–brain barrier (BBB). Especially sulfated steroids such as pregnenolone sulfate (PregS) and dehydroepiandrosterone sulfate (DHEAS) depend on transporter proteins to cross membranes. In this review, we discuss the involvement of ATP-binding cassette (ABC)- and solute carrier (SLC)-type membrane proteins in the transport of these compounds at the BBB and in the choroid plexus (CP), but also in the secretion from neurons and glial cells. Among the ABC transporters, especially BCRP (ABCG2) and several MRP/ABCC subfamily members (MRP1, MRP4, MRP8) are expressed in the brain and known to efflux conjugated steroids. Furthermore, several SLC transporters have been shown to mediate cellular uptake of steroid sulfates. These include members of the OATP/SLCO subfamily, namely OATP1A2 and OATP2B1, as well as OAT3 (SLC22A3), which have been reported to be expressed at the BBB, in the CP and in part in neurons. Furthermore, a role of the organic solute transporter OSTα-OSTβ (SLC51A/B) in brain DHEAS/PregS homeostasis has been proposed. This transporter was reported to be localized especially in steroidogenic cells of the cerebellum and hippocampus. To date, the impact of transporters on neurosteroid homeostasis is still poorly understood. Further insights are desirable also with regard to the therapeutic potential of these compounds.
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Affiliation(s)
- Markus Grube
- Department of Pharmacology, Center of Drug Absorption and Transport, University Medicine Greifswald, Greifswald, Germany
| | - Paul Hagen
- Department of Pharmacology, Center of Drug Absorption and Transport, University Medicine Greifswald, Greifswald, Germany
| | - Gabriele Jedlitschky
- Department of Pharmacology, Center of Drug Absorption and Transport, University Medicine Greifswald, Greifswald, Germany
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30
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Helms HC, Aldana BI, Groth S, Jensen MM, Waagepetersen HS, Nielsen CU, Brodin B. Characterization of the L-glutamate clearance pathways across the blood-brain barrier and the effect of astrocytes in an in vitro blood-brain barrier model. J Cereb Blood Flow Metab 2017; 37:3744-3758. [PMID: 28145808 PMCID: PMC5718321 DOI: 10.1177/0271678x17690760] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim was to characterize the clearance pathways for L-glutamate from the brain interstitial fluid across the blood-brain barrier using a primary in vitro bovine endothelial/rat astrocyte co-culture. Transporter profiling was performed using uptake studies of radiolabeled L-glutamate with co-application of transporter inhibitors and competing amino acids. Endothelial abluminal L-glutamate uptake was almost abolished by co-application of an EAAT-1 specific inhibitor, whereas luminal uptake was inhibited by L-glutamate and L-aspartate (1 mM). L-glutamate uptake followed Michaelis-Menten-like kinetics with high and low affinity at the abluminal and luminal membrane, respectively. This indicated that L-glutamate is taken up via EAAT-1 at the abluminal membrane and exits at the luminal membrane via a low affinity glutamate/aspartate transporter. Metabolism of L-glutamate and transport of metabolites was examined using [U-13C] L-glutamate. Intact L-glutamate and metabolites derived from oxidative metabolism were transported through the endothelial cells. High amounts of L-glutamate-derived lactate in the luminal medium indicated cataplerosis via malic enzyme. Thus, L-glutamate can be transported intact from brain to blood via the concerted action of abluminal and luminal transport proteins, but the total brain clearance is highly dependent on metabolism in astrocytes and endothelial cells followed by transport of metabolites.
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Affiliation(s)
- Hans Cc Helms
- 1 Department of Pharmacy, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Blanca I Aldana
- 2 Department of Drug Design and Pharmacology, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Simon Groth
- 1 Department of Pharmacy, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten M Jensen
- 1 Department of Pharmacy, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Helle S Waagepetersen
- 2 Department of Drug Design and Pharmacology, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Carsten U Nielsen
- 1 Department of Pharmacy, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,3 Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark
| | - Birger Brodin
- 1 Department of Pharmacy, The Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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31
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Abstract
1. Efflux proteins at the blood-brain barrier provide a mechanism for export of waste products of normal metabolism from the brain and help to maintain brain homeostasis. They also prevent entry into the brain of a wide range of potentially harmful compounds such as drugs and xenobiotics. 2. Conversely, efflux proteins also hinder delivery of therapeutic drugs to the brain and central nervous system used to treat brain tumours and neurological disorders. For bypassing efflux proteins, a comprehensive understanding of their structures, functions and molecular mechanisms is necessary, along with new strategies and technologies for delivery of drugs across the blood-brain barrier. 3. We review efflux proteins at the blood-brain barrier, classified as either ATP-binding cassette (ABC) transporters (P-gp, BCRP, MRPs) or solute carrier (SLC) transporters (OATP1A2, OATP1A4, OATP1C1, OATP2B1, OAT3, EAATs, PMAT/hENT4 and MATE1). 4. This includes information about substrate and inhibitor specificity, structural organisation and mechanism, membrane localisation, regulation of expression and activity, effects of diseases and conditions and the principal technique used for in vivo analysis of efflux protein activity: positron emission tomography (PET). 5. We also performed analyses of evolutionary relationships, membrane topologies and amino acid compositions of the proteins, and linked these to structure and function.
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Affiliation(s)
- Massoud Saidijam
- a Department of Molecular Medicine and Genetics , Research Centre for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences , Hamadan , Iran and
| | - Fatemeh Karimi Dermani
- a Department of Molecular Medicine and Genetics , Research Centre for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences , Hamadan , Iran and
| | - Sareh Sohrabi
- a Department of Molecular Medicine and Genetics , Research Centre for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences , Hamadan , Iran and
| | - Simon G Patching
- b School of BioMedical Sciences and the Astbury Centre for Structural Molecular Biology, University of Leeds , Leeds , UK
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32
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Hellsten SV, Hägglund MG, Eriksson MM, Fredriksson R. The neuronal and astrocytic protein SLC38A10 transports glutamine, glutamate, and aspartate, suggesting a role in neurotransmission. FEBS Open Bio 2017; 7:730-746. [PMID: 28593130 PMCID: PMC5458457 DOI: 10.1002/2211-5463.12219] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/03/2017] [Accepted: 03/08/2017] [Indexed: 12/21/2022] Open
Abstract
In brain cells, glutamine transporters are vital to monitor and control the levels of glutamate and GABA. There are 11 members of the SLC38 family of amino acid transporters of which eight have been functionally characterized. Here, we report the first histological and functional characterization of the previously orphan member, SLC38A10. We used pairwise global sequence alignments to determine the sequence identity between the SLC38 family members. SLC38A10 was found to share 20–25% transmembrane sequence identity with several family members, and was predicted to have 11 transmembrane helices. SLC38A10 immunostaining was abundant in mouse brain using a custom‐made anti‐SLC38A10 antibody and colocalization of SLC38A10 immunoreactivity with markers for neurons and astrocytes was detected. Using Xenopus laevis oocytes overexpressing SLC38A10, we show that SLC38A10 mediates bidirectional transport of l‐glutamine, l‐alanine, l‐glutamate, and d‐aspartate, and efflux of l‐serine. This profile mostly resembles system A members of the SLC38 family. In conclusion, the bidirectional transport of glutamine, glutamate, and aspartate by SLC38A10, and the immunostaining detected in neurons and astrocytes, suggest that SLC38A10 plays a role in pathways involved in neurotransmission.
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Affiliation(s)
- Sofie V Hellsten
- Department of Pharmaceutical Bioscience, Molecular Neuropharmacology Uppsala University Sweden
| | - Maria G Hägglund
- Department of Neuroscience, Functional Pharmacology Uppsala University Sweden
| | - Mikaela M Eriksson
- Department of Pharmaceutical Bioscience, Molecular Neuropharmacology Uppsala University Sweden
| | - Robert Fredriksson
- Department of Pharmaceutical Bioscience, Molecular Neuropharmacology Uppsala University Sweden
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33
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Hellsten SV, Lekholm E, Ahmad T, Fredriksson R. The gene expression of numerous SLC transporters is altered in the immortalized hypothalamic cell line N25/2 following amino acid starvation. FEBS Open Bio 2017; 7:249-264. [PMID: 28174690 PMCID: PMC5292668 DOI: 10.1002/2211-5463.12181] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/09/2016] [Accepted: 12/10/2016] [Indexed: 12/20/2022] Open
Abstract
Amino acids are known to play a key role in gene expression regulation, and in mammalian cells, amino acid signaling is mainly mediated via two pathways, the mammalian target of rapamycin complex 1 (mTORC1) pathway and the amino acid responsive (AAR) pathway. It is vital for cells to have a system to sense amino acid levels, in order to control protein and amino acid synthesis and catabolism. Amino acid transporters are crucial in these pathways, due to both their sensing and transport functions. In this large-scale study, an immortalized mouse hypothalamic cell line (N25/2) was used to study the gene expression changes following 1, 2, 3, 5 or 16 h of amino acid starvation. We focused on genes encoding solute carriers (SLCs) and putative SLCs, more specifically on amino acid transporters. The microarray contained 28 270 genes and 86.2% of the genes were expressed in the cell line. At 5 h of starvation, 1001 genes were upregulated and 848 genes were downregulated, and among these, 47 genes from the SLC superfamily or atypical SLCs were found. Of these, 15 were genes encoding amino acid transporters and 32 were genes encoding other SLCs or atypical SLCs. Increased expression was detected for genes encoding amino acid transporters from system A, ASC, L, N, T, xc-, and y+. Using GO annotations, genes involved in amino acid transport and amino acid transmembrane transporter activity were found to be most upregulated at 3 h and 5 h of starvation.
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Affiliation(s)
- Sofie V Hellsten
- Department of Pharmaceutical Bioscience, Molecular Neuropharmacology Uppsala University Sweden; Department of Neuroscience, Functional Pharmacology Uppsala University Sweden
| | - Emilia Lekholm
- Department of Pharmaceutical Bioscience, Molecular Neuropharmacology Uppsala University Sweden
| | - Tauseef Ahmad
- Department of Neuroscience, Functional Pharmacology Uppsala University Sweden
| | - Robert Fredriksson
- Department of Pharmaceutical Bioscience, Molecular Neuropharmacology Uppsala University Sweden
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34
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Lima A, Sousa H, Monteiro J, Azevedo R, Medeiros R, Seabra V. Genetic polymorphisms in low-dose methotrexate transporters: current relevance as methotrexate therapeutic outcome biomarkers. Pharmacogenomics 2015; 15:1611-35. [PMID: 25340735 DOI: 10.2217/pgs.14.116] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Methotrexate (MTX) is used in low doses to treat a variety of diseases. Although the mechanism responsible for its therapeutic action is unknown, MTX membrane transport proteins (influx and/or efflux) can be major determinants of pharmacokinetics, adverse drug reactions and clinical response profiles. With progess in pharmacogenomics, the improvement of the prediction of patients' therapeutic outcome treated with low doses of MTX will offer a powerful tool for the translation of transporter SNPs into clinical practice and will be essential to sustain a breakthrough in the field of personalized medicine. Therefore, this paper provides an update on the current data on SNPs in genes encoding low-dose MTX membrane transport proteins and their relevance as possible biomarkers of MTX therapeutic outcome.
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Affiliation(s)
- Aurea Lima
- CESPU, Institute of Research & Advanced Training in Health Sciences & Technologies, Department of Pharmaceutical Sciences, Higher Institute of Health Sciences - North (ISCS-N), Rua Central de Gandra 1317, 4585-116, Gandra PRD, Portugal
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35
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Lima A, Bernardes M, Azevedo R, Medeiros R, Seabra V. Pharmacogenomics of Methotrexate Membrane Transport Pathway: Can Clinical Response to Methotrexate in Rheumatoid Arthritis Be Predicted? Int J Mol Sci 2015; 16:13760-80. [PMID: 26086825 PMCID: PMC4490522 DOI: 10.3390/ijms160613760] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/03/2015] [Accepted: 06/04/2015] [Indexed: 12/18/2022] Open
Abstract
Background: Methotrexate (MTX) is widely used for rheumatoid arthritis (RA) treatment. Single nucleotide polymorphisms (SNPs) could be used as predictors of patients’ therapeutic outcome variability. Therefore, this study aims to evaluate the influence of SNPs in genes encoding for MTX membrane transport proteins in order to predict clinical response to MTX. Methods: Clinicopathological data from 233 RA patients treated with MTX were collected, clinical response defined, and patients genotyped for 23 SNPs. Genotype and haplotype analyses were performed using multivariate methods and a genetic risk index (GRI) for non-response was created. Results: Increased risk for non-response was associated to SLC22A11 rs11231809 T carriers; ABCC1 rs246240 G carriers; ABCC1 rs3784864 G carriers; CGG haplotype for ABCC1 rs35592, rs2074087 and rs3784864; and CGG haplotype for ABCC1 rs35592, rs246240 and rs3784864. GRI demonstrated that patients with Index 3 were 16-fold more likely to be non-responders than those with Index 1. Conclusions: This study revealed that SLC22A11 and ABCC1 may be important to identify those patients who will not benefit from MTX treatment, highlighting the relevance in translating these results to clinical practice. However, further validation by independent studies is needed to develop the field of personalized medicine to predict clinical response to MTX treatment.
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Affiliation(s)
- Aurea Lima
- Cooperativa de Ensino Superior Politécnico e Universitário (CESPU), Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde (IINFACTS), 4585-116 Gandra PRD, Portugal.
- Grupo de Oncologia Molecular & Patologia Viral-Centro de Investigação do Instituto Português de Oncologia do Porto (CI-IPOP), 4200-072 Porto, Portugal.
- Instituto de Ciências Biomédicas Abel Salazar da Universidade do Porto (ICBAS-UP), 4050-313 Porto, Portugal.
| | - Miguel Bernardes
- Faculdade de Medicina da Universidade do Porto (FMUP), 4200-319 Porto, Portugal.
- Departamento de Reumatologia do Centro Hospitalar de São João, 4200-319 Porto, Portugal.
| | - Rita Azevedo
- Instituto de Ciências Biomédicas Abel Salazar da Universidade do Porto (ICBAS-UP), 4050-313 Porto, Portugal.
- Grupo de Patologia & Terapêutica Experimental do Centro de Investigação do Instituto Português de Oncologia do Porto (CI-IPOP), 4200-072 Porto, Portugal.
| | - Rui Medeiros
- Grupo de Oncologia Molecular & Patologia Viral-Centro de Investigação do Instituto Português de Oncologia do Porto (CI-IPOP), 4200-072 Porto, Portugal.
- Instituto de Ciências Biomédicas Abel Salazar da Universidade do Porto (ICBAS-UP), 4050-313 Porto, Portugal.
| | - Vítor Seabra
- Cooperativa de Ensino Superior Politécnico e Universitário (CESPU), Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde (IINFACTS), 4585-116 Gandra PRD, Portugal.
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Sprowl JA, Ciarimboli G, Lancaster CS, Giovinazzo H, Gibson AA, Du G, Janke LJ, Cavaletti G, Shields AF, Sparreboom A. Oxaliplatin-induced neurotoxicity is dependent on the organic cation transporter OCT2. Proc Natl Acad Sci U S A. 2013;110:11199-11204. [PMID: 23776246 DOI: 10.1073/pnas.1305321110] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Oxaliplatin is an integral component of colorectal cancer therapy, but its clinical use is associated with a dose-limiting peripheral neurotoxicity. We found that the organic cation transporter 2 (OCT2) is expressed on dorsal root ganglia cells within the nervous system where oxaliplatin is known to accumulate. Cellular uptake of oxaliplatin was increased by 16- to 35-fold in cells overexpressing mouse Oct2 or human OCT2, and this process was associated with increased DNA platination and oxaliplatin-induced cytotoxicity. Furthermore, genetic or pharmacologic knockout of Oct2 protected mice from hypersensitivity to cold or mechanical-induced allodynia, which are established tests to assess acute oxaliplatin-induced neurotoxicity. These findings provide a rationale for the development of targeted approaches to mitigate this debilitating toxicity.
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Abstract
The choroid plexus (CP) is a highly vascularized tissue in the brain ventricles and acts as the blood-cerebrospinal fluid (CSF) barrier (BCSFB). A main function of the CP is to secrete CSF, which is accomplished by active transport of small ions and water from the blood side to the CSF side. The CP also supplies the brain with certain nutrients, hormones, and metal ions, while removing metabolites and xenobiotics from the CSF. Numerous membrane transporters are expressed in the CP in order to facilitate the solute exchange between the blood and the CSF. The solute carrier (SLC) superfamily represents a major class of transporters in the CP that constitutes the molecular mechanisms for CP function. Recently, we systematically and quantitatively examined Slc gene expression in 20 anatomically comprehensive brain areas in the adult mouse brain using high-quality in situ hybridization data generated by the Allen Brain Atlas. Here we focus our analysis on Slc gene expression at the BCSFB using previously obtained data. Of the 252 Slc genes present in the mouse brain, 202 Slc genes were found at detectable levels in the CP. Unsupervised hierarchical cluster analysis showed that the CP Slc gene expression pattern is substantially different from the other 19 analyzed brain regions. The majority of the Slc genes in the CP are expressed at low to moderate levels, whereas 28 Slc genes are present in the CP at the highest levels. These highly expressed Slc genes encode transporters involved in CSF secretion, energy production, and transport of nutrients, hormones, neurotransmitters, sulfate, and metal ions. In this review, the functional characteristics and potential importance of these Slc transporters in the CP are discussed, with particular emphasis on their localization and physiological functions at the BCSFB.
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Affiliation(s)
- Horace T B Ho
- Department of Pharmaceutics, University of Washington Seattle, WA, USA
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Haferkamp I, Schmitz-Esser S. The plant mitochondrial carrier family: functional and evolutionary aspects. Front Plant Sci 2012; 3:2. [PMID: 22639632 PMCID: PMC3355725 DOI: 10.3389/fpls.2012.00002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 01/03/2012] [Indexed: 05/19/2023]
Abstract
Mitochondria play a key role in respiration and energy production and are involved in multiple eukaryotic but also in several plant specific metabolic pathways. Solute carriers in the inner mitochondrial membrane connect the internal metabolism with that of the surrounding cell. Because of their common basic structure, these transport proteins affiliate to the mitochondrial carrier family (MCF). Generally, MCF proteins consist of six membrane spanning helices, exhibit typical conserved domains and appear as homodimers in the native membrane. Although structurally related, MCF proteins catalyze the specific transport of various substrates, such as nucleotides, amino acids, dicarboxylates, cofactors, phosphate or H(+). Recent investigations identified MCF proteins also in several other cellular compartments and therefore their localization and physiological function is not only restricted to mitochondria. MCF proteins are a characteristic feature of eukaryotes and bacterial genomes lack corresponding sequences. Therefore, the evolutionary origin of MCF proteins is most likely associated with the establishment of mitochondria. It is not clear whether the host cell, the symbiont, or the chimerical organism invented the ancient MCF sequence. Here, we try to explain the establishment of different MCF proteins and focus on the characteristics of members from plants, in particular from Arabidopsis thaliana.
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Affiliation(s)
- Ilka Haferkamp
- Zelluläre Physiologie/Membrantransport, Technische Universität KaiserslauternKaiserslautern, Germany
- *Correspondence: Ilka Haferkamp, Biologie, Zelluläre Physiologie/Membrantransport, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 22, 67653 Kaiserslautern, Germany. e-mail:
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