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Toyoda Y, Miyata H, Shigesawa R, Matsuo H, Suzuki H, Takada T. SVCT2/SLC23A2 is a sodium-dependent urate transporter: functional properties and practical application. J Biol Chem 2023; 299:104976. [PMID: 37390985 PMCID: PMC10374969 DOI: 10.1016/j.jbc.2023.104976] [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: 03/01/2023] [Revised: 05/10/2023] [Accepted: 06/12/2023] [Indexed: 07/02/2023] Open
Abstract
Urate transporters play a pivotal role in urate handling in the human body, but the urate transporters identified to date do not account for all known molecular processes of urate handling, suggesting the presence of latent machineries. We recently showed that a urate transporter SLC2A12 is also a physiologically important exporter of ascorbate (the main form of vitamin C in the body) that would cooperate with an ascorbate importer, sodium-dependent vitamin C transporter 2 (SVCT2). Based on the dual functions of SLC2A12 and cooperativity between SLC2A12 and SVCT2, we hypothesized that SVCT2 might be able to transport urate. To test this proposal, we conducted cell-based analyses using SVCT2-expressing mammalian cells. The results demonstrated that SVCT2 is a novel urate transporter. Vitamin C inhibited SVCT2-mediated urate transport with a half-maximal inhibitory concentration of 36.59 μM, suggesting that the urate transport activity may be sensitive to physiological ascorbate levels in blood. Similar results were obtained for mouse Svct2. Further, using SVCT2 as a sodium-dependent urate importer, we established a cell-based urate efflux assay that will be useful for identification of other novel urate exporters as well as functional characterization of nonsynonymous variants of already-identified urate exporters including ATP-binding cassette transporter G2. While more studies will be needed to elucidate the physiological impact of SVCT2-mediated urate transport, our findings deepen understanding of urate transport machineries.
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Affiliation(s)
- Yu Toyoda
- Department of Pharmacy, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Hiroshi Miyata
- Department of Pharmacy, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Ryuichiro Shigesawa
- Department of Pharmacy, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Hirotaka Matsuo
- Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Hiroshi Suzuki
- Department of Pharmacy, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Tappei Takada
- Department of Pharmacy, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan.
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Miyata H, Toyoda Y, Takada T, Hiragi T, Kubota Y, Shigesawa R, Koyama R, Ikegaya Y, Suzuki H. Identification of an exporter that regulates vitamin C supply from blood to the brain. iScience 2022; 25:103642. [PMID: 35106468 PMCID: PMC8786643 DOI: 10.1016/j.isci.2021.103642] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [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: 10/01/2021] [Revised: 11/12/2021] [Accepted: 12/14/2021] [Indexed: 01/09/2023] Open
Abstract
Vitamin C (VC) distribution in our body requires VC transporters. However, mammalian VC exporters are yet to be identified. Herein, to unravel this long-standing mystery, we focused on the pathways whereby VC moves from blood to the brain, which should require a VC entrance and exit system composed of an importer and a latent exporter. Via cell-based transport analyses of VC efflux and using knockout mice generated via the CRISPR-Cas9 system, we identified GLUT12/SLC2A12 as a physiologically important VC efflux protein expressed in the choroid plexus; Glut12/Slc2a12 knockout halved the cerebral VC levels, markedly increased VC accumulation in the choroid plexus, and reduced the cerebrospinal fluid VC levels. These findings facilitate our understanding of VC regulation and the physiological impact of VC in our body. A long-standing mystery in vitamin C handling in mammalians was uncovered GLUT12 was identified as a physiologically important vitamin C efflux protein—VCEP GLUT12 is expressed in the choroid plexus and acts as a vitamin C exporter Glut12 knockout halved the cerebral vitamin C levels in mice
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Affiliation(s)
- Hiroshi Miyata
- Department of Pharmacy, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Yu Toyoda
- Department of Pharmacy, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Tappei Takada
- Department of Pharmacy, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Toshimitsu Hiragi
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yu Kubota
- Department of Pharmacy, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Ryuichiro Shigesawa
- Department of Pharmacy, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Ryuta Koyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroshi Suzuki
- Department of Pharmacy, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
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Toyoda Y, Kawamura Y, Nakayama A, Nakaoka H, Higashino T, Shimizu S, Ooyama H, Morimoto K, Uchida N, Shigesawa R, Takeuchi K, Inoue I, Ichida K, Suzuki H, Shinomiya N, Takada T, Matsuo H. Substantial anti-gout effect conferred by common and rare dysfunctional variants of URAT1/SLC22A12. Rheumatology (Oxford) 2021; 60:5224-5232. [PMID: 33821957 PMCID: PMC8566256 DOI: 10.1093/rheumatology/keab327] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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: 01/26/2021] [Accepted: 03/28/2021] [Indexed: 01/17/2023] Open
Abstract
Objectives Gout, caused by chronic elevation of serum uric acid levels, is the commonest form of inflammatory arthritis. The causative effect of common and rare variants of ATP-binding cassette transporter G2 (ABCG2/BCRP) on gout risk has been studied, but little attention has been paid to the effect of common (rs121907892, p.W258X) and rare variants of urate transporter 1 (URAT1/SLC22A12) on gout, despite dysfunctional variants of URAT1 having been identified as pathophysiological causes of renal hypouricaemia. Methods To address this important but overlooked issue, we investigated the effects of these URAT1 variants on gout susceptibility, using targeted exon sequencing on 480 clinically defined gout cases and 480 controls of Japanese males in combination with a series of functional analyses of newly identified URAT1 variants. Results Our results show that both common and rare dysfunctional variants of URAT1 markedly decrease the risk of gout (OR 0.0338, reciprocal OR 29.6, P = 7.66 × 10−8). Interestingly, we also found that the URAT1-related protective effect on gout eclipsed the ABCG2-related causative effect (OR 2.30–3.32). Our findings reveal only one dysfunctional variant of URAT1 to have a substantial anti-gout effect, even in the presence of causative variants of ABCG2, a ‘gout gene’. Conclusion Our findings provide a better understanding of gout/hyperuricaemia and its aetiology that is highly relevant to personalized health care. The substantial anti-gout effect of common and rare variants of URAT1 identified in the present study support the genetic concept of a ‘Common Disease, Multiple Common and Rare Variant’ model.
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Affiliation(s)
- Yu Toyoda
- Department of Pharmacy, The University of Tokyo Hospital, Tokyo, Japan.,Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Yusuke Kawamura
- Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Akiyoshi Nakayama
- Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Hirofumi Nakaoka
- Division of Human Genetics, Department of Integrated Genetics, National Institute of Genetics, Mishima, Shizuoka, Japan.,Department of Cancer Genome Research, Sasaki Institute, Sasaki Foundation, Tokyo, Japan
| | - Toshihide Higashino
- Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Seiko Shimizu
- Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | | | - Keito Morimoto
- Department of Pharmacy, The University of Tokyo Hospital, Tokyo, Japan
| | - Naohiro Uchida
- Department of Pharmacy, The University of Tokyo Hospital, Tokyo, Japan
| | | | - Kenji Takeuchi
- Department of Preventive Medicine, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Ituro Inoue
- Division of Human Genetics, Department of Integrated Genetics, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Kimiyoshi Ichida
- Department of Pathophysiology, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan.,Division of Kidney and Hypertension, Jikei University School of Medicine, Tokyo, Japan
| | - Hiroshi Suzuki
- Department of Pharmacy, The University of Tokyo Hospital, Tokyo, Japan
| | - Nariyoshi Shinomiya
- Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Tappei Takada
- Department of Pharmacy, The University of Tokyo Hospital, Tokyo, Japan
| | - Hirotaka Matsuo
- Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
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