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Liu WW, Dong HJ, Zhang Z, Ma XH, Liu S, Huang W, Wang X. Analyzing chemical composition of Sargentodoxae caulis water extract and their hypouricemia effect in hyperuricemic mice. Fitoterapia 2024; 175:105926. [PMID: 38537887 DOI: 10.1016/j.fitote.2024.105926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/17/2024] [Accepted: 03/24/2024] [Indexed: 04/26/2024]
Abstract
Hyperuricemia (HUA) is a metabolic disease characterized by the increase of serum uric acid (UA) level. Sargentodoxae Caulis (SC) is a commonly used herbal medicine for the treatment of gouty arthritis, traumatic swelling, and rheumatic arthritis in clinic. In this study, a total of fifteen compounds were identified in SC water extract using UHPLC-Q-TOF-MS/MS, including three phenolic acids, seven phenolic glycosides, four organic acids, and one lignan. Then, to study the hypouricemia effect of SC, a HUA mouse model was induced using a combination of PO, HX, and 20% yeast feed. After 14 days of treatment with the SC water extract, the levels of serum UA, creatinine (CRE), blood urea nitrogen (BUN) were reduced significantly, and the organ indexes were restored, the xanthine oxidase (XOD) activity were inhibited as well. Meanwhile, SC water extract could ameliorate the pathological status of kidneys and intestine of HUA mice. Additionally, quantitative real-time PCR (qRT-PCR) and western blotting results showed that SC water extract could increase the expression of ATP binding cassette subfamily G member 2 (ABCG2), organic cation transporter 1 (OCT1), organic anion transporter 1 (OAT1) and organic anion transporter 3 (OAT3), whereas decrease the expression of glucose transporter 9 (GLUT9). This study provided a data support for the clinical application of SC in the treatment of HUA.
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Affiliation(s)
- Wen-Wen Liu
- Key Laboratory for Applied Technology of Sophisticated Analytical Instruments of Shandong Province, Shandong Analysis and Test Center, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; Key Laboratory for Natural Active Pharmaceutical Constituents Research in Universities of Shandong Province, School of Pharmaceutical Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; College of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan 250300, China
| | - Hong-Jing Dong
- Key Laboratory for Applied Technology of Sophisticated Analytical Instruments of Shandong Province, Shandong Analysis and Test Center, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; Key Laboratory for Natural Active Pharmaceutical Constituents Research in Universities of Shandong Province, School of Pharmaceutical Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; College of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan 250300, China
| | - Zhe Zhang
- College of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan 250300, China
| | - Xin-Hui Ma
- College of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan 250300, China
| | - Shuang Liu
- Key Laboratory for Applied Technology of Sophisticated Analytical Instruments of Shandong Province, Shandong Analysis and Test Center, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; Key Laboratory for Natural Active Pharmaceutical Constituents Research in Universities of Shandong Province, School of Pharmaceutical Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China
| | - Wei Huang
- Shandong Academy of Chinese Medicine, Jinan 250014, China
| | - Xiao Wang
- Key Laboratory for Applied Technology of Sophisticated Analytical Instruments of Shandong Province, Shandong Analysis and Test Center, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; Key Laboratory for Natural Active Pharmaceutical Constituents Research in Universities of Shandong Province, School of Pharmaceutical Sciences, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; College of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan 250300, China.
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Packer M. Hyperuricemia and Gout Reduction by SGLT2 Inhibitors in Diabetes and Heart Failure: JACC Review Topic of the Week. J Am Coll Cardiol 2024; 83:371-381. [PMID: 38199714 DOI: 10.1016/j.jacc.2023.10.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/06/2023] [Accepted: 10/17/2023] [Indexed: 01/12/2024]
Abstract
Gout is characterized by increased production of purines (through the pentose phosphate pathway), which is coupled with reduced renal or intestinal excretion of urate. Concurrent upregulation of nutrient surplus signaling (mammalian target of rapamycin and hypoxia-inducible factor-1a) and downregulation of nutrient deprivation signaling (sirtuin-1 and adenosine monophosphate-activated protein kinase) redirects glucose toward anabolic pathways (rather than adenosine triphosphate production), thus promoting heightened oxidative stress and cardiomyocyte and proximal tubular dysfunction, leading to cardiomyopathy and kidney disease. Hyperuricemia is a marker (rather than a driver) of these cellular stresses. By inducing a state of starvation mimicry in a state of nutrient surplus, sodium-glucose cotransporter-2 inhibitors decrease flux through the pentose phosphate pathway (thereby attenuating purine and urate synthesis) while promoting renal urate excretion. These convergent actions exert a meaningful effect to lower serum uric acid by ≈0.6 to 1.5 mg/dL and to reduce the risk of gout by 30% to 50% in large-scale clinical trials.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Dallas, Texas, USA; Imperial College, London, United Kingdom.
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Sakaguchi YM, Wiriyasermkul P, Matsubayashi M, Miyasaka M, Sakaguchi N, Sahara Y, Takasato M, Kinugawa K, Sugie K, Eriguchi M, Tsuruya K, Kuniyasu H, Nagamori S, Mori E. Identification of three distinct cell populations for urate excretion in human kidneys. J Physiol Sci 2024; 74:1. [PMID: 38166558 PMCID: PMC10763458 DOI: 10.1186/s12576-023-00894-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 11/26/2023] [Indexed: 01/04/2024]
Abstract
In humans, uric acid is an end-product of purine metabolism. Urate excretion from the human kidney is tightly regulated by reabsorption and secretion. At least eleven genes have been identified as human renal urate transporters. However, it remains unclear whether all renal tubular cells express the same set of urate transporters. Here, we show renal tubular cells are divided into three distinct cell populations for urate handling. Analysis of healthy human kidneys at single-cell resolution revealed that not all tubular cells expressed the same set of urate transporters. Only 32% of tubular cells were related to both reabsorption and secretion, while the remaining tubular cells were related to either reabsorption or secretion at 5% and 63%, respectively. These results provide physiological insight into the molecular function of the transporters and renal urate handling on single-cell units. Our findings suggest that three different cell populations cooperate to regulate urate excretion from the human kidney, and our proposed framework is a step forward in broadening the view from the molecular to the cellular level of transport capacity.
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Affiliation(s)
- Yoshihiko M Sakaguchi
- Department of Future Basic Medicine, Nara Medical University, Kashihara, Nara, Japan
- Center for SI Medical Research, The Jikei University School of Medicine, Tokyo, Japan
- Department of Laboratory Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Pattama Wiriyasermkul
- Center for SI Medical Research, The Jikei University School of Medicine, Tokyo, Japan
- Department of Laboratory Medicine, The Jikei University School of Medicine, Tokyo, Japan
- Department of Biological Chemistry and Food Sciences, Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan
| | - Masaya Matsubayashi
- Biological Research Department, Research Institute, Fuji Yakuhin Co., Ltd., Saitama, Japan
| | - Masaki Miyasaka
- Center for SI Medical Research, The Jikei University School of Medicine, Tokyo, Japan
- Department of Laboratory Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Nau Sakaguchi
- Department of Future Basic Medicine, Nara Medical University, Kashihara, Nara, Japan
| | - Yoshiki Sahara
- RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo, Japan
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Minoru Takasato
- RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo, Japan
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Kaoru Kinugawa
- Department of Future Basic Medicine, Nara Medical University, Kashihara, Nara, Japan
- Department of Neurology, Nara Medical University, Kashihara, Nara, Japan
| | - Kazuma Sugie
- Department of Neurology, Nara Medical University, Kashihara, Nara, Japan
| | - Masahiro Eriguchi
- Department of Nephrology, Nara Medical University, Kashihara, Nara, Japan
| | - Kazuhiko Tsuruya
- Department of Nephrology, Nara Medical University, Kashihara, Nara, Japan
| | - Hiroki Kuniyasu
- Department of Molecular Pathology, Nara Medical University, Kashihara, Nara, Japan
| | - Shushi Nagamori
- Center for SI Medical Research, The Jikei University School of Medicine, Tokyo, Japan.
- Department of Laboratory Medicine, The Jikei University School of Medicine, Tokyo, Japan.
- Department of Collaborative Research for Bio-Molecular Dynamics, Nara Medical University, Kashihara, Nara, Japan.
| | - Eiichiro Mori
- Department of Future Basic Medicine, Nara Medical University, Kashihara, Nara, Japan.
- V-iCliniX Laboratory, Nara Medical University, Kashihara, Nara, Japan.
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Taylor SI, Cherng HR, Yazdi ZS, Montasser ME, Whitlatch HB, Mitchell BD, Shuldiner AR, Streeten EA, Beitelshees AL. Pharmacogenetics of sodium-glucose co-transporter-2 inhibitors: Validation of a sex-agnostic pharmacodynamic biomarker. Diabetes Obes Metab 2023; 25:3512-3520. [PMID: 37608471 PMCID: PMC10829524 DOI: 10.1111/dom.15246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 07/21/2023] [Accepted: 07/28/2023] [Indexed: 08/24/2023]
Abstract
AIM To validate pharmacodynamic responses to sodium-glucose co-transporter-2 (SGLT2) inhibitors and test for association with genetic variants in SLC5A4, SLC5A9, and SLC2A9. METHODS Canagliflozin (300 mg), a SGLT2 inhibitor, was administered to 30 healthy volunteers. Several endpoints were measured to assess clinically relevant responses, including drug-induced increases in urinary excretion of glucose, sodium and uric acid. RESULTS This pilot study confirmed that canagliflozin (300 mg) triggered acute changes in mean levels of several biomarkers: fasting plasma glucose (-4.1 mg/dL; P = 6 × 10-5 ), serum creatinine (+0.05 mg/dL; P = 8 × 10-4 ) and serum uric acid (-0.90 mg/dL; P = 5 × 10-10 ). The effects of sex on glucosuria depended upon how data were normalized. Whereas males' responses were ~60% greater when data were normalized to body surface area, males and females exhibited similar responses when glucosuria was expressed as grams of urinary glucose per gram-creatinine. The magnitude of glucosuria was not significantly correlated with fasting plasma glucose, estimated glomerular filtration rate or age in those healthy individuals without diabetes with an estimated glomerular filtration rate of more than 60 mL/min/1.73m2 . CONCLUSIONS Normalizing data relative to creatinine excretion will facilitate including data from males and females in a single analysis. Furthermore, because our ongoing pharmacogenomic study (NCT02891954) is conducted in healthy individuals, this will facilitate detection of genetic associations with limited confounding by other factors such as HbA1c and renal function.
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Affiliation(s)
- Simeon I. Taylor
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Hua-Ren Cherng
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Zhinous Shahidzadeh Yazdi
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - May E. Montasser
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Hilary B. Whitlatch
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Braxton D. Mitchell
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Alan R. Shuldiner
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Elizabeth A. Streeten
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Amber L. Beitelshees
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
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Taylor SI, Cherng HR, Yazdi ZS, Montasser ME, Whitlatch HB, Mitchell BD, Shuldiner AR, Streeten EA, Beitelshees AL. Pharmacogenetics of SGLT2 Inhibitors: Validation of a sex-agnostic pharmacodynamic biomarker. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.03.07.23286875. [PMID: 36945579 PMCID: PMC10029014 DOI: 10.1101/2023.03.07.23286875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Aim SGLT2 inhibitors provide multiple benefits to patients with type 2 diabetes - including improved glycemic control and decreased risks of cardiorenal disease. Because drug responses vary among individuals, we initiated investigations to identify genetic variants associated with the magnitude of drug responses. Methods Canagliflozin (300 mg) was administered to 30 healthy volunteers. Several endpoints were measured to assess clinically relevant responses - including drug-induced increases in urinary excretion of glucose, sodium, and uric acid. Results This pilot study confirmed that canagliflozin (300 mg) triggered acute changes in mean levels of several biomarkers: fasting plasma glucose (-4.1 mg/dL; p=6x10), serum creatinine (+0.05 mg/dL; p=8×10 -4 ), and serum uric acid (-0.90 mg/dL; p=5×10 -10 ). The effects of sex on glucosuria depended upon how data were normalized. Whereas males' responses were ∼60% greater when data were normalized to body surface area, males and females exhibited similar responses when glucosuria was expressed as grams of urinary glucose per gram-creatinine. The magnitude of glucosuria was not significantly correlated with fasting plasma glucose, estimated GFR, or age in these healthy non-diabetic individuals with estimated GFR>60 mL/min/1.73m 2 . Conclusions Normalizing data relative to creatinine excretion will facilitate including data from males and females in a single analysis. Furthermore, because our ongoing pharmacogenomic study ( NCT02891954 ) is conducted in healthy individuals, this will facilitate detection of genetic associations with limited confounding by other factors such as age and renal function. Registration NCT02462421 ( clinicaltrials.gov ). Funding Research grants from the National Institute of Diabetes and Digestive and Kidney Diseases: R21DK105401, R01DK108942, T32DK098107, and P30DK072488.
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Affiliation(s)
- Simeon I. Taylor
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Hua-Ren Cherng
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Zhinous Shahidzadeh Yazdi
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - May E. Montasser
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Hilary B. Whitlatch
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Braxton D. Mitchell
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Alan R. Shuldiner
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Elizabeth A. Streeten
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Amber L. Beitelshees
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
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Perdomo-Ramirez A, Cordoba-Lanus E, Trujillo-Frias CJ, Gonzalez-Navasa C, Ramos-Trujillo E, Luis-Yanes MI, Garcia-Nieto V, Claverie-Martin F. Pathogenic Variants of SLC22A12 (URAT1) and SLC2A9 (GLUT9) in Spanish Patients with Renal Hypouricemia: Founder Effect of SLC2A9 Variant c.374C>T; p.(T125M). Int J Mol Sci 2023; 24:ijms24098455. [PMID: 37176161 PMCID: PMC10179447 DOI: 10.3390/ijms24098455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023] Open
Abstract
Renal hypouricemia (RHUC) is a rare inherited disorder characterized by impaired urate reabsorption in the proximal tubule resulting in low urate serum levels and increased urate excretion. Some patients may present severe complications such as exercise-induced acute renal failure and nephrolithiasis. RHUC is caused by inactivating mutations in the SLC22A12 (RHUC type 1) or SLC2A9 (RHUC type 2) genes, which encode urate transporters URAT1 and GLUT9, respectively. In this study, our goal was to identify mutations associated with twenty-one new cases with RHUC through direct sequencing of SLC22A12 and SLC2A9 coding exons. Additionally, we carried out an SNPs-haplotype analysis to determine whether the rare SLC2A9 variant c.374C>T; p.(T125M), which is recurrent in Spanish families with RHUC type 2, had a common-linked haplotype. Six intragenic informative SNPs were analyzed using PCR amplification from genomic DNA and direct sequencing. Our results showed that ten patients carried the SLC22A12 mutation c.1400C>T; p.(T467M), ten presented the SLC2A9 mutation c.374C>T, and one carried a new SLC2A9 heterozygous mutation, c.593G>A; p.(R198H). Patients carrying the SLC2A9 mutation c.374C>T share a common-linked haplotype, confirming that it emerged due to a founder effect.
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Affiliation(s)
- Ana Perdomo-Ramirez
- Unidad de Investigacion, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain
| | - Elizabeth Cordoba-Lanus
- Unidad de Investigacion, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain
- Instituto Universitario de Enfermedades Tropicales y Salud Publica de Canarias (IUETSPC), Universidad de La Laguna, 38296 Santa Cruz de Tenerife, Spain
| | - Carmen Jane Trujillo-Frias
- Unidad de Investigacion, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain
| | - Carolina Gonzalez-Navasa
- Unidad de Investigacion, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain
- Seccion Medicina, Departamento de Medicina Fisica y Farmacologia, Facultad de Ciencias de la Salud, Universidad de La Laguna, 38200 Santa Cruz de Tenerife, Spain
| | - Elena Ramos-Trujillo
- Unidad de Investigacion, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain
- Seccion Medicina, Departamento de Medicina Fisica y Farmacologia, Facultad de Ciencias de la Salud, Universidad de La Laguna, 38200 Santa Cruz de Tenerife, Spain
| | - Maria Isabel Luis-Yanes
- Unidad de Nefrologia Pediatrica, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain
| | - Victor Garcia-Nieto
- Unidad de Nefrologia Pediatrica, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain
| | - Felix Claverie-Martin
- Unidad de Investigacion, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain
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Mandal AK, Leask MP, Sumpter NA, Choi HK, Merriman TR, Mount DB. Genetic and Physiological Effects of Insulin-Like Growth Factor-1 (IGF-1) on Human Urate Homeostasis. J Am Soc Nephrol 2023; 34:451-466. [PMID: 36735516 PMCID: PMC10103387 DOI: 10.1681/asn.0000000000000054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 10/25/2022] [Indexed: 01/22/2023] Open
Abstract
SIGNIFICANCE STATEMENT Hyperinsulinemia induces hyperuricemia by activating net renal urate reabsorption in the renal proximal tubule. The basolateral reabsorptive urate transporter GLUT9a appears to be the dominant target for insulin. By contrast, IGF-1 infusion reduces serum urate (SU), through mechanisms unknown. Genetic variants of IGF1R associated with reduced SU have increased IGF-1R expression and interact with genes encoding the GLUT9 and ABCG2 urate transporters, in a sex-specific fashion, which controls the SU level. Activation of IGF-1/IGF-1R signaling in Xenopus oocytes modestly activates GLUT9a and inhibits insulin's stimulatory effect on the transporter, which also activates multiple secretory urate transporters-ABCG2, ABCC4, OAT1, and OAT3. The results collectively suggest that IGF-1 reduces SU by activating secretory urate transporters and inhibiting insulin's action on GLUT9a. BACKGROUND Metabolic syndrome and hyperinsulinemia are associated with hyperuricemia. Insulin infusion in healthy volunteers elevates serum urate (SU) by activating net urate reabsorption in the renal proximal tubule, whereas IGF-1 infusion reduces SU by mechanisms unknown. Variation within the IGF1R gene also affects SU levels. METHODS Colocalization analyses of a SU genome-wide association studies signal at IGF1R and expression quantitative trait loci signals in cis using COLOC2, RT-PCR, Western blotting, and urate transport assays in transfected HEK 293T cells and in Xenopus laevis oocytes. RESULTS Genetic association at IGF1R with SU is stronger in women and is mediated by control of IGF1R expression. Inheritance of the urate-lowering homozygous genotype at the SLC2A9 locus is associated with a differential effect of IGF1R genotype between men and women. IGF-1, through IGF-1R, stimulated urate uptake in human renal proximal tubule epithelial cells and transfected HEK 293T cells, through activation of IRS1, PI3/Akt, MEK/ERK, and p38 MAPK; urate uptake was inhibited in the presence of uricosuric drugs, specific inhibitors of protein tyrosine kinase, PI3 kinase (PI3K), ERK, and p38 MAPK. In X. laevis oocytes expressing ten individual urate transporters, IGF-1 through endogenous IGF-1R stimulated urate transport mediated by GLUT9, OAT1, OAT3, ABCG2, and ABCC4 and inhibited insulin's stimulatory action on GLUT9a and OAT3. IGF-1 significantly activated Akt and ERK. Specific inhibitors of PI3K, ERK, and PKC significantly affected IGF-1 stimulation of urate transport in oocytes. CONCLUSIONS The combined results of infusion, genetics, and transport experiments suggest that IGF-1 reduces SU by activating urate secretory transporters and inhibiting insulin's action.
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Affiliation(s)
- Asim K. Mandal
- Renal Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Megan P. Leask
- Biochemistry Department, University of Otago, Dunedin, South Island, New Zealand
- Division of Rheumatology and Clinical Immunology, University of Alabama, Birmingham, Alabama
| | - Nicholas A. Sumpter
- Division of Rheumatology and Clinical Immunology, University of Alabama, Birmingham, Alabama
| | - Hyon K. Choi
- Division of Rheumatology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Tony R. Merriman
- Biochemistry Department, University of Otago, Dunedin, South Island, New Zealand
- Division of Rheumatology and Clinical Immunology, University of Alabama, Birmingham, Alabama
| | - David B. Mount
- Renal Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
- Renal Division, VA Boston Healthcare System, Harvard Medical School, Boston, Massachusetts
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Gao T, Xu J, Xiao Y, Li J, Hu W, Su X, Shen X, Yu W, Chen Z, Huang B, Li H, Wang X. Therapeutic effects and mechanisms of N-(9,10-anthraquinone-2-ylcarbonyl) xanthine oxidase inhibitors on hyperuricemia. Front Pharmacol 2022; 13:950699. [PMID: 36120294 PMCID: PMC9478491 DOI: 10.3389/fphar.2022.950699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
Objective: To observe the antioxidative effects of N-(9,10-anthraquinone-2-ylcarbonyl) xanthine oxidase inhibitors (NAY) in vitro and in vivo models of hyperuricemia and explore the mechanism.Methods: A classical experimental method of acute toxicity and a chronic toxicity test were used to compare the toxic effects of different doses of NAY in mice. The hyperuricemia mouse model was established by gavage of potassium oxonate in vivo. After treatment with different doses of NAY (low dose: 10 mg/kg, medium dose: 20 mg/kg, and high dose: 40 mg/kg) and allopurinol (positive drug, 10 mg/kg), observe the levels of uric acid (UA), creatinine (CRE), and urea nitrogen (BUN) in urine and serum, respectively, and detect the activities of xanthine oxidase in the liver. The hyperuricemia cell model was induced by adenosine and xanthine oxidase in vitro. The cells were given different doses of NAY (50, 100, and 200 μmol/L) and allopurinol (100 μmol/L). Then the culture supernatant UA level of the medium was measured. The next step was to detect the xanthine oxidase activity in the liver and AML12 cells, and the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammatory factors in the kidney and serum of mice. Western blot was used to detect xanthine oxidase protein expression in mouse liver tissue and AML12 cells, ASC, Caspase-1, NLRP3, GLUT9, OAT1, and OAT3 protein expression in mouse kidney tissue and HK-2 cells. Hematoxylin–eosin staining was used to stain the liver and kidney tissues of mice and observe the tissue lesions.Results: NAY had little effect on blood routine and biochemical indexes of mice, but significantly reduced the serum UA level. NAY significantly reduced the level of UA in hyperuricemia mice and cells by inhibiting xanthine oxidase activity and reduced the levels of TNF-α, IL-6, and other inflammatory factors in serum and kidney of mice. NAY can inhibit inflammation by inhibiting the NLRP3 pathway. In addition, NAY can downregulate GLUT9 protein expression and upregulate OAT1 and OAT3 protein expression to reduce the UA level by promoting UA excretion and inhibiting UA reabsorption.Conclusion: These findings suggested that NAY produced dual hypouricemic actions. On the one hand, it can inhibit the formation of UA by inhibiting xanthine oxidase inhibitors activity, and on the other hand, it can promote the excretion of UA by regulating the UA transporter. It provides new ideas for the development of hyperuricemia drugs in the future.
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Affiliation(s)
- Tianshu Gao
- Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Jin Xu
- Department of Nephrology, Jurong Hospital Affiliated to Jiangsu University, Jurong, China
| | - Yuxiao Xiao
- Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Jiaqi Li
- Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Weifeng Hu
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Xiaoyu Su
- Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Xudong Shen
- Department of Pathology, Jiangsu Province Hospital on Integration of Chinese and Western Medicine, Nanjing, China
| | - Wan Yu
- Department of Neurosurgical, Jiangsu Province Hospital on Integration of Chinese and Western Medicine, Nanjing, China
| | - Zhen Chen
- Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Baosheng Huang
- Department of Neurosurgery, Sir Run Run Hospital, Nanjing Medical University, Nanjing, China
| | - Honglei Li
- Department of Pharmacy, Kangda College of Nanjing Medical University, Lianyungang, China
- *Correspondence: Honglei Li, ; Xing Wang,
| | - Xing Wang
- Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing, China
- *Correspondence: Honglei Li, ; Xing Wang,
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9
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Zhao Z, Liu J, Kuang P, Luo J, Surineni G, Cen X, Wu T, Cao Y, Zhou P, Pang J, Zhang Q, Chen J. Discovery of novel verinurad analogs as dual inhibitors of URAT1 and GLUT9 with improved Druggability for the treatment of hyperuricemia. Eur J Med Chem 2022; 229:114092. [PMID: 34998055 DOI: 10.1016/j.ejmech.2021.114092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/22/2021] [Accepted: 12/26/2021] [Indexed: 11/28/2022]
Abstract
Verinurad (RDEA3170) is a selective URAT1 inhibitor under investigation for the treatment of gout and hyperuricemia. In an effort to further improve the pharmacodynamics/pharmacokinetics of verinurad and to increase the structural diversity, we designed novel verinurad analogs by introducing a linker (e.g. aminomethyl, amino or oxygen) between the naphthalene and the pyridine ring to increase the flexibility. These compounds were synthesized and tested for their in vitro URAT1-inhibitory activity. Most compounds exhibited potent inhibitory activities against URAT1 with IC50 values ranging from 0.24 μM to 16.35 μM. Among them, compound KPH2f exhibited the highest URAT1-inhibitory activity with IC50 of 0.24 μM, comparable to that of verinurad (IC50 = 0.17 μM). KPH2f also inhibited GLUT9 with an IC50 value of 9.37 ± 7.10 μM, indicating the dual URAT1/GLUT9 targeting capability. In addition, KPH2f showed little effects on OAT1 and ABCG2, and thus was unlikely to cause OAT1/ABCG2-mediated drug-drug interactions and/or to neutralize the uricosuric effects of URAT1/GLUT9 inhibitors. Importantly, KPH2f (10 mg/kg) was equally effective in reducing serum uric acid levels and exhibited higher uricosuric effects in a mice hyperuricemia model, as compared to verinurad (10 mg/kg). Furthermore, KPH2f demonstrated favorable pharmacokinetic properties with an oral bioavailability of 30.13%, clearly better than that of verinurad (21.47%). Moreover, KPH2f presented benign safety profiles without causing hERG toxicity, cytotoxicity in vitro (lower than verinurad), and renal damage in vivo. Collectively, these results suggest that KPH2f represents a novel, safe and effective dual URAT1/GLUT9 inhibitor with improved druggabilities and is worthy of further investigation as an anti-hyperuricemic drug candidate.
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Affiliation(s)
- Zean Zhao
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Jin Liu
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Peihua Kuang
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Jian Luo
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Goverdhan Surineni
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Xiaolin Cen
- Good Clinical Practice Development, Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China
| | - Ting Wu
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Ying Cao
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Pingzheng Zhou
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Jianxin Pang
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China.
| | - Qun Zhang
- Good Clinical Practice Development, Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China.
| | - Jianjun Chen
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China.
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10
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Vallon V, Nakagawa T. Renal Tubular Handling of Glucose and Fructose in Health and Disease. Compr Physiol 2021; 12:2995-3044. [PMID: 34964123 PMCID: PMC9832976 DOI: 10.1002/cphy.c210030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The proximal tubule of the kidney is programmed to reabsorb all filtered glucose and fructose. Glucose is taken up by apical sodium-glucose cotransporters SGLT2 and SGLT1 whereas SGLT5 and potentially SGLT4 and GLUT5 have been implicated in apical fructose uptake. The glucose taken up by the proximal tubule is typically not metabolized but leaves via the basolateral facilitative glucose transporter GLUT2 and is returned to the systemic circulation or used as an energy source by distal tubular segments after basolateral uptake via GLUT1. The proximal tubule generates new glucose in metabolic acidosis and the postabsorptive phase, and fructose serves as an important substrate. In fact, under physiological conditions and intake, fructose taken up by proximal tubules is primarily utilized for gluconeogenesis. In the diabetic kidney, glucose is retained and gluconeogenesis enhanced, the latter in part driven by fructose. This is maladaptive as it sustains hyperglycemia. Moreover, renal glucose retention is coupled to sodium retention through SGLT2 and SGLT1, which induces secondary deleterious effects. SGLT2 inhibitors are new anti-hyperglycemic drugs that can protect the kidneys and heart from failing independent of kidney function and diabetes. Dietary excess of fructose also induces tubular injury. This can be magnified by kidney formation of fructose under pathological conditions. Fructose metabolism is linked to urate formation, which partially accounts for fructose-induced tubular injury, inflammation, and hemodynamic alterations. Fructose metabolism favors glycolysis over mitochondrial respiration as urate suppresses aconitase in the tricarboxylic acid cycle, and has been linked to potentially detrimental aerobic glycolysis (Warburg effect). © 2022 American Physiological Society. Compr Physiol 12:2995-3044, 2022.
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Affiliation(s)
- Volker Vallon
- Division of Nephrology and Hypertension, Department of Medicine, University of California San Diego, La Jolla, California, USA,Department of Pharmacology, University of California San Diego, La Jolla, California, USA,VA San Diego Healthcare System, San Diego, California, USA,Correspondence to and
| | - Takahiko Nakagawa
- Division of Nephrology, Rakuwakai-Otowa Hospital, Kyoto, Japan,Correspondence to and
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11
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Identification of two novel heterozygous SLC2A9 mutations in a Chinese woman and review of literature. Clin Chim Acta 2021; 523:58-64. [PMID: 34499869 DOI: 10.1016/j.cca.2021.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/20/2021] [Accepted: 09/03/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVE This study is aimed to describe the clinical and genetic characteristics of a Chinese woman diagnosed with renal hypouricemia type 2 (RHUC2). We also summarize the advances in research on RHUC2 by reviewing related literature. METHODS We measured clinical parameters of a 57-year-old female and performed whole-exome sequencing to screen for mutations. Human embryonic kidney 293 cells were transiently transfected with plasmids containing wild-type or mutants. Relative mRNA quantification was determined by real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR). RESULTS This patient was diagnosed with diabetes and coronary heart disease. In addition, a decrease in 24-hour urinary chloride was observed. Two novel heterozygous variants of SLC2A9 (NM_020041.2): c.682-2_682-1insC and c.267C > G (p.Y89X) were identified. The mini-gene splicing assay revealed that c.682-2_682-1insC variant resulted in a frameshift mutation p. E228PfsX23. There was a statistically significant difference in mRNA expression level between the two mutants and the wild-type. CONCLUSIONS These findings strongly suggest that the two novel mutations are the causative agents of RHUC2. In particular, our findings provide further insights into the function of SLC2A9 and mechanisms of the complications.
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12
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Mandal AK, Leask MP, Estiverne C, Choi HK, Merriman TR, Mount DB. Genetic and Physiological Effects of Insulin on Human Urate Homeostasis. Front Physiol 2021; 12:713710. [PMID: 34408667 PMCID: PMC8366499 DOI: 10.3389/fphys.2021.713710] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 07/02/2021] [Indexed: 12/19/2022] Open
Abstract
Insulin and hyperinsulinemia reduce renal fractional excretion of urate (FeU) and play a key role in the genesis of hyperuricemia and gout, via uncharacterized mechanisms. To explore this association further we studied the effects of genetic variation in insulin-associated pathways on serum urate (SU) levels and the physiological effects of insulin on urate transporters. We found that urate-associated variants in the human insulin (INS), insulin receptor (INSR), and insulin receptor substrate-1 (IRS1) loci associate with the expression of the insulin-like growth factor 2, IRS1, INSR, and ZNF358 genes; additionally, we found genetic interaction between SLC2A9 and the three loci, most evident in women. We also found that insulin stimulates the expression of GLUT9 and increases [14C]-urate uptake in human proximal tubular cells (PTC-05) and HEK293T cells, transport activity that was effectively abrogated by uricosurics or inhibitors of protein tyrosine kinase (PTK), PI3 kinase, MEK/ERK, or p38 MAPK. Heterologous expression of individual urate transporters in Xenopus oocytes revealed that the [14C]-urate transport activities of GLUT9a, GLUT9b, OAT10, OAT3, OAT1, NPT1 and ABCG2 are directly activated by insulin signaling, through PI3 kinase (PI3K)/Akt, MEK/ERK and/or p38 MAPK. Given that the high-capacity urate transporter GLUT9a is the exclusive basolateral exit pathway for reabsorbed urate from the renal proximal tubule into the blood, that insulin stimulates both GLUT9 expression and urate transport activity more than other urate transporters, and that SLC2A9 shows genetic interaction with urate-associated insulin-signaling loci, we postulate that the anti-uricosuric effect of insulin is primarily due to the enhanced expression and activation of GLUT9.
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Affiliation(s)
- Asim K. Mandal
- Renal Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Megan P. Leask
- Biochemistry Department, University of Otago, Dunedin, New Zealand
- Division of Rheumatology and Clinical Immunology, University of Alabama, Birmingham, AL, United States
| | - Christopher Estiverne
- Renal Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Hyon K. Choi
- Division of Rheumatology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Tony R. Merriman
- Biochemistry Department, University of Otago, Dunedin, New Zealand
- Division of Rheumatology and Clinical Immunology, University of Alabama, Birmingham, AL, United States
| | - David B. Mount
- Renal Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
- Renal Division, VA Boston Healthcare System, Harvard Medical School, Boston, MA, United States
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13
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Zhang Y, Tan X, Lin Z, Li F, Yang C, Zheng H, Li L, Liu H, Shang J. Fucoidan from Laminaria japonica Inhibits Expression of GLUT9 and URAT1 via PI3K/Akt, JNK and NF-κB Pathways in Uric Acid-Exposed HK-2 Cells. Mar Drugs 2021; 19:md19050238. [PMID: 33922488 PMCID: PMC8145932 DOI: 10.3390/md19050238] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/16/2021] [Accepted: 04/19/2021] [Indexed: 12/12/2022] Open
Abstract
This work aimed to investigate the effect of fucoidan (FPS) on urate transporters induced by uric acid (UA). The results showed that UA stimulated the expression of glucose transporter 9 (GLUT9) and urate transporter 1 (URAT1) in HK-2 cells, and FPS could reverse the effect. Moreover, UA could activate NF-κB, JNK and PI3K/Akt pathways, but both pathway inhibitors and FPS inhibited the UA-induced activation of these three pathways. These data suggested that FPS effectively inhibited the expression induction of reabsorption transporters URAT1 and GLUT9 by UA, through repressing the activation of NF-κB, JNK and PI3K/Akt signal pathways in HK-2 cells. The in vitro research findings support the in vivo results that FPS reduces serum uric acid content in hyperuricemia mice and rats through inhibiting the expression of URAT1 and GLUT9 in renal tubular epithelial cells. This study provides a theoretical basis for the application of FPS in the treatment of hyperuricemia.
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Affiliation(s)
- Yu Zhang
- College of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China; (Y.Z.); (X.T.); (Z.L.); (F.L.)
- Guangxi Key Laboratory of Buffalo Genetics, Reproduction and Breeding, Guangxi Buffalo Research Institute, Chinese Academy of Agricultural Sciences, Nanning 530001, China; (C.Y.); (H.Z.); (L.L.)
| | - Xiaohui Tan
- College of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China; (Y.Z.); (X.T.); (Z.L.); (F.L.)
- Guangxi Key Laboratory of Buffalo Genetics, Reproduction and Breeding, Guangxi Buffalo Research Institute, Chinese Academy of Agricultural Sciences, Nanning 530001, China; (C.Y.); (H.Z.); (L.L.)
| | - Zhen Lin
- College of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China; (Y.Z.); (X.T.); (Z.L.); (F.L.)
| | - Fangping Li
- College of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China; (Y.Z.); (X.T.); (Z.L.); (F.L.)
| | - Chunyan Yang
- Guangxi Key Laboratory of Buffalo Genetics, Reproduction and Breeding, Guangxi Buffalo Research Institute, Chinese Academy of Agricultural Sciences, Nanning 530001, China; (C.Y.); (H.Z.); (L.L.)
| | - Haiying Zheng
- Guangxi Key Laboratory of Buffalo Genetics, Reproduction and Breeding, Guangxi Buffalo Research Institute, Chinese Academy of Agricultural Sciences, Nanning 530001, China; (C.Y.); (H.Z.); (L.L.)
| | - Lingyu Li
- Guangxi Key Laboratory of Buffalo Genetics, Reproduction and Breeding, Guangxi Buffalo Research Institute, Chinese Academy of Agricultural Sciences, Nanning 530001, China; (C.Y.); (H.Z.); (L.L.)
| | - Huazhong Liu
- College of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China; (Y.Z.); (X.T.); (Z.L.); (F.L.)
- Correspondence: authors: (H.L.); (J.S.)
| | - Jianghua Shang
- Guangxi Key Laboratory of Buffalo Genetics, Reproduction and Breeding, Guangxi Buffalo Research Institute, Chinese Academy of Agricultural Sciences, Nanning 530001, China; (C.Y.); (H.Z.); (L.L.)
- Correspondence: authors: (H.L.); (J.S.)
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14
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Chen Y, Zhao Z, Li Y, Li L, Jiang Y, Cao Y, Zhou P, Wu T, Pang J. Characterizations of the Urate Transporter, GLUT9, and Its Potent Inhibitors by Patch-Clamp Technique. SLAS DISCOVERY 2020; 26:450-459. [PMID: 32844721 DOI: 10.1177/2472555220949501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Glucose transporter 9 (GLUT9), which transports urate in an electrogenic and voltage-dependent manner, plays an important role in the maintenance of normal blood uric acid/urate levels. In the present study, we established a cell model based on the single-electrode patch-clamp technique for characterization of GLUT9 and explored the inhibitory effects of benzobromarone (BM) and probenecid (PB) on urate-induced currents in mouse GLUT9a (mGLUT9a)-expressing HEK-293T cells. The results showed that uric acid, rather than glucose perfusion, led to a rapid and large outward current by mGLUT9a in dose-, voltage-, and pH-dependent manners. BM prominently and irreversibly inhibited the uric acid-induced currents through mGLUT9a, and PB weakly and reversibly inhibited mGLUT9a. We found that depletion of K+ in the external solution significantly strengthened the blockade of BM on mGLUT9a. In addition, an enhanced inhibitory rate of BM was detected when the pH of the external solution was changed from 7.4 to 5.5, indicating that BM functions optimally in an acidic environment. In conclusion, the combination of the established cell model with patch-clamp techniques first revealed the function properties of GLUT9 inhibitors and may provide potential benefits to the study of GLUT9 inhibitors as antihyperuricemic or antigout agents.
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Affiliation(s)
- Yanyu Chen
- Guangdong Provincial Key Laboratory of Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Zean Zhao
- Guangdong Provincial Key Laboratory of Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Yongmei Li
- Guangdong Provincial Key Laboratory of Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Lu Li
- Guangdong Provincial Key Laboratory of Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Yu Jiang
- Guangdong Provincial Key Laboratory of Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Ying Cao
- Guangdong Provincial Key Laboratory of Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Pingzheng Zhou
- Guangdong Provincial Key Laboratory of Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Ting Wu
- Guangdong Provincial Key Laboratory of Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Jianxin Pang
- Guangdong Provincial Key Laboratory of Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
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15
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Stanirowski PJ, Lipa M, Bomba-Opoń D, Wielgoś M. Expression of placental glucose transporter proteins in pregnancies complicated by fetal growth disorders. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2020; 123:95-131. [PMID: 33485490 DOI: 10.1016/bs.apcsb.2019.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
During pregnancy fetal growth disorders, including fetal macrosomia and fetal growth restriction (FGR) are associated with numerous maternal-fetal complications, as well as due to the adverse effect of the intrauterine environment lead to an increased morbidity in adult life. Accumulating evidence suggests that occurrence of fetal macrosomia or FGR, may be associated with alterations in the transfer of nutrients across the placenta, in particular of glucose. The placental expression and activity of specific GLUT transporters are the main regulatory factors in the process of maternal-fetal glucose exchange. This review article summarizes the results of previous studies on the expression of GLUT transporters in the placenta, concentrating on human pregnancies complicated by intrauterine fetal growth disorders. Characteristics of each transporter protein found in the placenta is presented, alterations in the location and expression of GLUT isoforms observed in individual placental compartments are described, and the factors regulating the expression of selected GLUT proteins are examined. Based on the above data, the potential function of each GLUT isoform in the maternal-fetal glucose transfer is determined. Further on, a detailed analysis of changes in the expression of glucose transporters in pregnancies complicated by fetal growth disorders is given, and significance of these modifications for the pathogenesis of fetal macrosomia and FGR is discussed. In the final part novel interventional approaches that might reduce the risk associated with abnormalities of intrauterine fetal growth through modifications of placental GLUT-mediated glucose transfer are explored.
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Affiliation(s)
- Paweł Jan Stanirowski
- 1(st) Department of Obstetrics and Gynecology, Medical University of Warsaw, Warsaw, Poland; Club 35. Polish Society of Gynecologists and Obstetricians, Warsaw, Poland
| | - Michał Lipa
- 1(st) Department of Obstetrics and Gynecology, Medical University of Warsaw, Warsaw, Poland; Club 35. Polish Society of Gynecologists and Obstetricians, Warsaw, Poland
| | - Dorota Bomba-Opoń
- 1(st) Department of Obstetrics and Gynecology, Medical University of Warsaw, Warsaw, Poland
| | - Mirosław Wielgoś
- 1(st) Department of Obstetrics and Gynecology, Medical University of Warsaw, Warsaw, Poland
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16
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Hou R, Panda C, Voruganti VS. Heterogeneity in Metabolic Responses to Dietary Fructose. Front Genet 2019; 10:945. [PMID: 31737029 PMCID: PMC6834945 DOI: 10.3389/fgene.2019.00945] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 09/05/2019] [Indexed: 12/30/2022] Open
Abstract
Consumption of fructose has dramatically increased in past few decades in children and adults. Increasing evidence indicates that added sugars (particularly fructose) have adverse effects on metabolism and lead to numerous cardiometabolic diseases. Although both fructose and glucose are components of sucrose and high fructose corn syrup, the sugars have different metabolic fates in the human body and the effects of fructose on health are thought to be more adverse than glucose. Studies have also shown that the metabolic effects of fructose differ between individuals based on their genetic background, as individuals with specific SNPs and risk alleles seem to be more susceptible to the adverse metabolic effects of fructose. The current review discusses the metabolic effects of fructose on key complex diseases and discusses the heterogeneity in metabolic responses to dietary fructose in humans.
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Affiliation(s)
- Ruixue Hou
- Department of Nutrition and UNC Nutrition Research Institute, University of North Carolina at Chapel Hill, Kannapolis, NC, United States
| | - Chinmayee Panda
- Department of Nutrition and UNC Nutrition Research Institute, University of North Carolina at Chapel Hill, Kannapolis, NC, United States
| | - V Saroja Voruganti
- Department of Nutrition and UNC Nutrition Research Institute, University of North Carolina at Chapel Hill, Kannapolis, NC, United States
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17
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Edwards A, Auberson M, Ramakrishnan SK, Bonny O. A model of uric acid transport in the rat proximal tubule. Am J Physiol Renal Physiol 2019; 316:F934-F947. [DOI: 10.1152/ajprenal.00603.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The objective of the present study was to theoretically investigate the mechanisms underlying uric acid transport in the proximal tubule (PT) of rat kidneys, and their modulation by factors, including Na+, parathyroid hormone, ANG II, and Na+-glucose cotransporter-2 inhibitors. To that end, we incorporated the transport of uric acid and its conjugate anion urate in our mathematical model of water and solute transport in the rat PT. The model accounts for parallel urate reabsorption and secretion pathways on apical and basolateral membranes and their coupling to lactate and α-ketoglutarate transport. Model results agree with experimental findings at the segment level. Net reabsorption of urate by the rat PT is predicted to be ~70% of the filtered load, with a rate of urate removal from the lumen that is 50% higher than the rate of urate secretion. The model suggests that apical URAT1 deletion significantly reduces net urate reabsorption across the PT, whereas ATP-binding cassette subfamily G member 2 dysfunction affects it only slightly. Inactivation of basolateral glucose transporter-9 raises fractional urate excretion above 100%, as observed in patients with renal familial hypouricemia. Furthermore, our results suggest that reducing Na+ reabsorption across Na+/H+ exchangers or Na+-glucose cotransporters augments net urate reabsorption. The model predicts that parathyroid hormone reduces urate excretion, whereas ANG II increases it. In conclusion, we have developed the first model of uric acid transport in the rat PT; this model provides a framework to gain greater insight into the numerous solutes and coupling mechanisms that affect the renal handing of uric acid.
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Affiliation(s)
- Aurélie Edwards
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Muriel Auberson
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Suresh K. Ramakrishnan
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Olivier Bonny
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
- Service of Nephrology, Lausanne University Hospital, Lausanne, Switzerland
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18
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Illsley NP, Baumann MU. Human placental glucose transport in fetoplacental growth and metabolism. Biochim Biophys Acta Mol Basis Dis 2018; 1866:165359. [PMID: 30593896 DOI: 10.1016/j.bbadis.2018.12.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 11/13/2018] [Accepted: 12/06/2018] [Indexed: 02/07/2023]
Abstract
While efficient glucose transport is essential for all cells, in the case of the human placenta, glucose transport requirements are two-fold; provision of glucose for the growing fetus in addition to the supply of glucose required the changing metabolic needs of the placenta itself. The rapidly evolving environment of placental cells over gestation has significant consequences for the development of glucose transport systems. The two-fold transport requirement of the placenta means also that changes in expression will have effects not only for the placenta but also for fetal growth and metabolism. This review will examine the localization, function and evolution of placental glucose transport systems as they are altered with fetal development and the transport and metabolic changes observed in pregnancy pathologies.
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Affiliation(s)
- Nicholas P Illsley
- Center for Abnormal Placentation, Department of Obstetrics and Gynecology, Hackensack University Medical Center, Hackensack, NJ, USA.
| | - Marc U Baumann
- Department of Obstetrics and Gynaecology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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19
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Carreño D, Corro N, Torres-Estay V, Véliz LP, Jaimovich R, Cisternas P, San Francisco IF, Sotomayor PC, Tanasova M, Inestrosa NC, Godoy AS. Fructose and prostate cancer: toward an integrated view of cancer cell metabolism. Prostate Cancer Prostatic Dis 2018; 22:49-58. [PMID: 30104655 DOI: 10.1038/s41391-018-0072-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/13/2018] [Accepted: 06/29/2018] [Indexed: 01/07/2023]
Abstract
Activation of glucose transporter-1 (Glut-1) gene expression is a molecular feature of cancer cells that increases glucose uptake and metabolism. Increased glucose uptake is the basis for the clinical localization of primary tumors using positron emission tomography (PET) and 2-deoxy-2-[18F]-fluoro-D-glucose (FDG) as a radiotracer. However, previous studies have demonstrated that a considerable number of cancers, which include prostate cancer (CaP), express low to undetectable levels of Glut-1 and that FDG-PET has limited clinical applicability in CaP. This observation could be explained by a low metabolic activity of CaP cells that may be overcome using different hexoses, such as fructose, as the preferred energy source. However, these hypotheses have not been examined critically in CaP. This review article summarizes what is currently known about transport and metabolism of hexoses, and more specifically fructose, in CaP and provides experimental evidences indicating that CaP cells may have increased capacity to transport and metabolize fructose in vitro and in vivo. Moreover, this review highlights recent findings that allow better understanding of how metabolism of fructose may regulate cancer cell proliferation and how fructose uptake and metabolism, through the de novo lipogenesis pathway, may provide new opportunities for CaP early diagnosis, staging, and treatment.
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Affiliation(s)
- Daniela Carreño
- Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Néstor Corro
- Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Loreto P Véliz
- Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Pedro Cisternas
- Centro de Envejecimiento y Regeneración (CARE), Department of Cell Biology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Paula C Sotomayor
- Center for Integrative Medicine and Innovative Science, Faculty of Medicine, Universidad Andres Bello, Santiago, Chile
| | - Marina Tanasova
- Department of Chemistry, Michigan Technological University, Houghton, MI, 49931, USA
| | - Nibaldo C Inestrosa
- Centro de Envejecimiento y Regeneración (CARE), Department of Cell Biology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alejandro S Godoy
- Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile. .,Department of Urology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, 14263, USA.
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20
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Abstract
Xenopus laevis oocytes are a useful heterologous expression system for expressing glucose transporters (GLUTs) and examining their functions. In this chapter, we provide a detailed protocol on oocyte extraction and preparation for GLUT9 protein expression. Furthermore, we describe the determination of GLUT9 overexpression level by biotinylation and Western blotting analysis. Finally, we also describe how GLUT9-expressing oocytes can be used to measure urate kinetics by radioisotopes as well as two-microelectrode voltage clamping techniques.
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Benn CL, Dua P, Gurrell R, Loudon P, Pike A, Storer RI, Vangjeli C. Physiology of Hyperuricemia and Urate-Lowering Treatments. Front Med (Lausanne) 2018; 5:160. [PMID: 29904633 PMCID: PMC5990632 DOI: 10.3389/fmed.2018.00160] [Citation(s) in RCA: 134] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 05/08/2018] [Indexed: 12/18/2022] Open
Abstract
Gout is the most common form of inflammatory arthritis and is a multifactorial disease typically characterized by hyperuricemia and monosodium urate crystal deposition predominantly in, but not limited to, the joints and the urinary tract. The prevalence of gout and hyperuricemia has increased in developed countries over the past two decades and research into the area has become progressively more active. We review the current field of knowledge with emphasis on active areas of hyperuricemia research including the underlying physiology, genetics and epidemiology, with a focus on studies which suggest association of hyperuricemia with common comorbidities including cardiovascular disease, renal insufficiency, metabolic syndrome and diabetes. Finally, we discuss current therapies and emerging drug discovery efforts aimed at delivering an optimized clinical treatment strategy.
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Affiliation(s)
| | - Pinky Dua
- Pfizer Ltd., Cambridge, United Kingdom
| | | | | | - Andrew Pike
- DMPK, Oncology, IMED Biotech Unit, AstraZeneca, Cambridge, United Kingdom
| | - R Ian Storer
- IMED Biotech Unit, Medicinal Chemistry, Discovery Sciences, AstraZeneca, Cambridge, United Kingdom
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22
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Karwur FF, Pujiastuti DR. Review Article: URIC ACID HOMEOSTASIS AND DISTURBANCES. FOLIA MEDICA INDONESIANA 2017. [DOI: 10.20473/fmi.v53i4.7164] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
This review examined the homeostasis of uric acid in human body and analyzed recent studies of the affecting major variables. Normal uric acid concentration in male is 3.5-7.2 mg/dL and in female is 2.6-6 mg/dL. Daily turnover of normal uric acid ranges from 498-1392 mg/day, miscible pool is 767-1650 mg, reabsorption is 8064 mg/day, renal excretion is 262-620 mg/day and intestine 186-313 mg/day. The dynamics of uric acid is influenced by factors of food, drink, age, history of disease, and genetic. High purine dietary consumption increases blood uric acid by 1-2 mg/dL, 213-290 g/day fructose drinks increases 0.52-1.7 mg/dL, 1.5 g/kgBW sucrose increases 0.61 mg/dL, and 10-20 ml/kgBW beer increases 0.50-0.92 mg/dL. The ABCG2 gene plays a role in bringing uric acid out of the body by 114.31-162.73 mg/dL, SLC2A9 of 5.43-20.17 mg/dL, and SLC22A12 of 5.77-6.71 mg/dL. The data described the homeostasis of uric acid and the magnitude of the impact of environmental (consumption of food, beverages, and lifestyle) and genetic factors. Understanding uric acid homeostasis and its disturbances is important in managing diseases as a consequence of hyperuricemia and hypouryscemia
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23
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Genetic risk scores, sex and dietary factors interact to alter serum uric acid trajectory among African-American urban adults. Br J Nutr 2017; 117:686-697. [PMID: 28345493 DOI: 10.1017/s0007114517000411] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Serum uric acid (SUA), a causative agent for gout among others, is affected by both genetic and dietary factors, perhaps differentially by sex. We evaluated cross-sectional (SUAbase) and longitudinal (SUArate) associations of SUA with a genetic risk score (GRS), diet and sex. We then tested the interactive effect of GRS, diet and sex on SUA. Longitudinal data on 766 African-American urban adults participating in the Healthy Aging in Neighborhood of Diversity across the Lifespan study were used. In all, three GRS for SUA were created from known SUA-associated SNP (GRSbase (n 12 SNP), GRSrate (n 3 SNP) and GRStotal (n 15 SNP)). Dietary factors included added sugar, total alcohol, red meat, total fish, legumes, dairy products, caffeine and vitamin C. Mixed-effects linear regression models were conducted. SUAbase was higher among men compared with that among women, and increased with GRStotal tertiles. SUArate was positively associated with legume intake in women (γ=+0·14; 95 % CI +0·06, +0·22, P=0·001) and inversely related to dairy product intake in both sexes combined (γ=-0·042; 95 % CI -0·075, -0·009), P=0·010). SUAbase was directly linked to alcohol consumption among women (γ=+0·154; 95 % CI +0·046, +0·262, P=0·005). GRSrate was linearly related to SUArate only among men. Legume consumption was also positively associated with SUArate within the GRStotal's lowest tertile. Among women, a synergistic interaction was observed between GRSrate and red meat intake in association with SUArate. Among men, a synergistic interaction between low vitamin C and genetic risk was found. In sum, sex-diet, sex-gene and gene-diet interactions were detected in determining SUA. Further similar studies are needed to replicate our findings.
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24
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Mandal AK, Mercado A, Foster A, Zandi-Nejad K, Mount DB. Uricosuric targets of tranilast. Pharmacol Res Perspect 2017; 5:e00291. [PMID: 28357121 PMCID: PMC5368959 DOI: 10.1002/prp2.291] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 10/24/2016] [Accepted: 11/10/2016] [Indexed: 11/08/2022] Open
Abstract
Uric acid, generated from the metabolism of purines, has both proven and emerging roles in human disease. Serum uric acid in humans is determined by production and by the net balance of reabsorption and secretion in kidney and intestine. In the human kidney, epithelial reabsorption dominates over secretion, such that in normal subjects there is at least 90% net reabsorption of filtered urate resulting in a fractional excretion of <10%. Tranilast, an anti-inflammatory drug with pleiotropic effects, has a marked hypouricemic, uricosuric effect in humans. We report here that tranilast is a potent inhibitor of [14C]-urate transport mediated by the major reabsorptive urate transporters (URAT1, GLUT9, OAT4, and OAT10) in Xenopus oocytes; this provides an unequivocal molecular mechanism for the drug's uricosuric effect. Tranilast was found to inhibit urate transport mediated by URAT1 and GLUT9 in a fully reversible and noncompetitive (mixed) manner. In addition, tranilast inhibits the secretory urate transporters NPT1, OAT1, and OAT3 without affecting the secretory efflux pump ABCG2. Notably, while benzbromarone and probenecid inhibited urate as well as nicotinate transport, tranilast inhibited the urate transport function of URAT1, GLUT9, OAT4, OAT10, and NPT1, without significantly affecting nicotinate transport mediated by SMCT1 (IC 50 ~1.1 mmol/L), SMCT2 (IC 50 ~1.0 mmol/L), and URAT1 (IC 50 ~178 μmol/L). In summary, tranilast causes uricosuria by inhibiting all the major reabsorptive urate transporters, selectively affecting urate over nicotinate transport. These data have implications for the treatment of hyperuricemia and gout, the pharmacology of tranilast, and the structure-function analysis of urate transport.
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Affiliation(s)
- Asim K Mandal
- Renal Divisions VA Boston Healthcare System and Brigham and Women's Hospital Boston Massachusetts
| | - Adriana Mercado
- Renal Divisions Departamento de Nefrología Instituto Nacional de Cardiología Ignacio Chávez Mexico City Mexico
| | - Andria Foster
- Renal Divisions VA Boston Healthcare System and Brigham and Women's Hospital Boston Massachusetts
| | - Kambiz Zandi-Nejad
- Renal Division Beth Israel Deaconess Medical Center Boston Massachusetts
| | - David B Mount
- Renal Divisions VA Boston Healthcare System and Brigham and Women's Hospital Boston Massachusetts
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25
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Long W, Panigrahi R, Panwar P, Wong K, O′Neill D, Chen XZ, Lemieux MJ, Cheeseman CI. Identification of Key Residues for Urate Specific Transport in Human Glucose Transporter 9 (hSLC2A9). Sci Rep 2017; 7:41167. [PMID: 28117388 PMCID: PMC5259734 DOI: 10.1038/srep41167] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 12/14/2016] [Indexed: 11/08/2022] Open
Abstract
Human glucose transporter 9 (hSLC2A9) is critical in human urate homeostasis, for which very small deviations can lead to chronic or acute metabolic disorders. Human SLC2A9 is unique in that it transports hexoses as well as the organic anion, urate. This ability is in contrast to other homologous sugar transporters such as glucose transporters 1 and 5 (SLC2A1 &SLC2A5) and the xylose transporter (XylE), despite the fact that these transporters have similar protein structures. Our in silico substrate docking study has revealed that urate and fructose bind within the same binding pocket in hSLC2A9, yet with distinct orientations, and allowed us to identify novel residues for urate binding. Our functional studies confirmed that N429 is a key residue for both urate binding and transport. We have shown that cysteine residues, C181, C301 and C459 in hSLC2A9 are also essential elements for mediating urate transport. Additional data from chimæric protein analysis illustrated that transmembrane helix 7 of hSLC2A9 is necessary for urate transport but not sufficient to allow urate transport to be induced in glucose transporter 5 (hSLC2A5). These data indicate that urate transport in hSLC2A9 involves several structural elements rather than just a unique substrate binding pocket.
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Affiliation(s)
- Wentong Long
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Alberta, Canada
| | - Rashmi Panigrahi
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Alberta, Canada
| | - Pankaj Panwar
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Alberta, Canada
| | - Kenneth Wong
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Alberta, Canada
| | - Debbie O′Neill
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Alberta, Canada
| | - Xing-Zhen Chen
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Alberta, Canada
| | - M. Joanne Lemieux
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Alberta, Canada
| | - Chris I. Cheeseman
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Alberta, Canada
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26
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Abstract
Elevated serum urate concentration is the primary cause of gout. Understanding the processes that affect serum urate concentration is important for understanding the etiology of gout and thereby understanding treatment. Urate handing in the human body is a complex system including three major processes: production, renal elimination, and intestinal elimination. A change in any one of these can affect both the steady-state serum urate concentration as well as other urate processes. The remarkable complexity underlying urate regulation and its maintenance at high levels in humans suggests that this molecule could potentially play an interesting role other than as a mere waste product to be eliminated as rapidly as possible.
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Affiliation(s)
- David Hyndman
- Ardea Biosciences, Inc., Biology Department, 9390 Towne Centre Drive, San Diego, CA, 92121, USA.
| | - Sha Liu
- Ardea Biosciences, Inc., Biology Department, 9390 Towne Centre Drive, San Diego, CA, 92121, USA
| | - Jeffrey N Miner
- Ardea Biosciences, Inc., Biology Department, 9390 Towne Centre Drive, San Diego, CA, 92121, USA
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27
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Mancikova A, Krylov V, Hurba O, Sebesta I, Nakamura M, Ichida K, Stiburkova B. Functional analysis of novel allelic variants in URAT1 and GLUT9 causing renal hypouricemia type 1 and 2. Clin Exp Nephrol 2015; 20:578-584. [DOI: 10.1007/s10157-015-1186-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/13/2015] [Indexed: 11/28/2022]
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28
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Abstract
PURPOSE OF REVIEW To update recent developments in medications targeting hyperuricemia, but not including medications recently labelled in the European Union and the United States. RECENT FINDINGS A new xanthine oxidase inhibitor, Topiloric (Fujiyakuhin Co., Ltd. Japan) Uriadec (Sanwa Kagaku Kenkyusho Co., Ltd. Japan), has been developed and labelled in Japan. An inhibitor of purine nucleoside phosphorylase, Ulodesine, is in development in combination with allopurinol. The rest of the medications in the pipeline for hyperuricemia are targeting renal transporters of uric acid, mainly URAT1 and OAT4, acting as uricosuric agents. Most of them, such as lesinurad and arhalofenate, are being tested in trials in combination with allopurinol and febuxostat. The most potent RDEA3170 is being tested in monotherapy, but also associated with febuxostat. Recently, medications showing dual activity, inhibiting both xanthine oxidoreductase and URAT1, have been communicated or started exploratory clinical trials. There is no report of medications targeting other transporters such as Glut9 or ABCG2. SUMMARY There are a number of medications in the pipeline targeting hyperuricemia, mostly uricosurics in combination with xanthine oxidase inhibitors, but some targeting both xanthine oxidoreductase and URAT1. Increasing the number of available medications will ensure proper control of hyperuricemia to target serum urate levels in the near future for most, if not all, patients with hyperuricemia.
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29
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Ware EB, Riehle E, Smith JA, Zhao W, Turner ST, Kardia SLR, Lieske JC. SLC2A9 Genotype Is Associated with SLC2A9 Gene Expression and Urinary Uric Acid Concentration. PLoS One 2015; 10:e0128593. [PMID: 26167684 PMCID: PMC4500555 DOI: 10.1371/journal.pone.0128593] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 04/28/2015] [Indexed: 12/17/2022] Open
Abstract
Objectives SLC2A9 gene variants have been associated with urinary uric acid (UA) concentration, but little is known about the functional mechanism linking these gene variants with UA. SLC2A9 encodes a UA transporter present in the proximal tubule of the kidney, and gene expression levels of SLC2A9 and other genes in the uricosuric pathway (ABCG2, SLC17A1, SLC17A3, and SLC22A12) could potentially mediate the relationship between SLC2A9 gene variants and urinary UA excretion. Methods The association between urinary UA concentrations and single nucleotide polymorphisms (SNPs) within the SLC2A9 gene region, expression levels of genes in the uricosuric pathway, and dietary protein intake were analyzed for a sample of non-Hispanic white participants from the Genetic Epidemiology Network of Arteriopathy (GENOA) cohort. The SLC2A9 SNP most significantly associated with urinary UA concentration was then tested for associations with gene expression levels from uric acid absorption/secretion associated genes. Models including interactions between dietary protein (total, animal, and vegetable) and genetic factors were also assessed. Results The most significant SLC2A9 SNP associated with urinary UA (rs12509955, corrected p = 0.001) was also associated with SLC2A9 gene expression levels (corrected p = 0.0084); however, SLC2A9 gene expression levels were not significantly associated with urinary UA concentrations (p = 0.509). The interactions between rs12509955 and total dietary protein, and SLC2A9 gene-level gene expression and dietary vegetable protein on the outcome of urinary UA were marginally significant (p = 0.11 and p = 0.07, respectively). Gene expression level of one SLC2A9 transcript had a significant interaction with dietary animal protein (SLC2A9-001 ENST00000506583, p = 0.01) and a marginally significant interaction with total dietary protein (p = 0.07) on urinary UA. Conclusion Our results illustrate that SNPs in the SLC2A9 gene influence SLC2A9 gene expression as well as urinary UA excretion. Evidence is also suggestive that gene-by-diet interactions may disproportionately increase urinary UA in genetically susceptible individuals that consume higher amounts of protein.
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Affiliation(s)
- Erin B. Ware
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, United States of America
- Institute for Social Research, University of Michigan, Ann Arbor, MI, United States of America
| | - Ellen Riehle
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, United States of America
| | - Jennifer A. Smith
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, United States of America
| | - Wei Zhao
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, United States of America
| | - Stephen T. Turner
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, United States of America
| | - Sharon L. R. Kardia
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, United States of America
- * E-mail:
| | - John C. Lieske
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, United States of America
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States of America
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30
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Long W, Panwar P, Witkowska K, Wong K, O'Neill D, Chen XZ, Lemieux MJ, Cheeseman CI. Critical Roles of Two Hydrophobic Residues within Human Glucose Transporter 9 (hSLC2A9) in Substrate Selectivity and Urate Transport. J Biol Chem 2015; 290:15292-303. [PMID: 25922070 DOI: 10.1074/jbc.m114.611178] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Indexed: 12/22/2022] Open
Abstract
High blood urate levels (hyperuricemia) have been found to be a significant risk factor for cardiovascular diseases and inflammatory arthritis, such as hypertension and gout. Human glucose transporter 9 (hSLC2A9) is an essential protein that mainly regulates urate/hexose homeostasis in human kidney and liver. hSLC2A9 is a high affinity-low capacity hexose transporter and a high capacity urate transporter. Our previous studies identified a single hydrophobic residue in trans-membrane domain 7 of class II glucose transporters as a determinant of fructose transport. A mutation of isoleucine 335 to valine (I355V) in hSLC2A9 can reduce fructose transport while not affecting glucose fluxes. This current study demonstrates that the I335V mutant transports urate similarly to the wild type hSLC2A9; however, Ile-335 is necessary for urate/fructose trans-acceleration exchange to occur. Furthermore, Trp-110 is a critical site for urate transport. Two structural models of the class II glucose transporters, hSLC2A9 and hSLC2A5, based on the crystal structure of hSLC2A1 (GLUT1), reveal that Ile-335 (or the homologous Ile-296 in hSLC2A5) is a key component for protein conformational changes when the protein translocates substrates. The hSLC2A9 model also predicted that Trp-110 is a crucial site that could directly interact with urate during transport. Together, these studies confirm that hSLC2A9 transports both urate and fructose, but it interacts with them in different ways. Therefore, this study advances our understanding of how hSLC2A9 mediates urate and fructose transport, providing further information for developing pharmacological agents to treat hyperuricemia and related diseases, such as gout, hypertension, and diabetes.
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Affiliation(s)
| | - Pankaj Panwar
- the Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada and
| | - Kate Witkowska
- the Department of Clinical Pharmacology, John Vane Science Centre, William Harvey Research Centre, Charter House Square Campus, QMUL, London EC16BQ, England
| | | | | | | | - M Joanne Lemieux
- the Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada and
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Abstract
Genome-wide association studies that scan the genome for common genetic variants associated with phenotype have greatly advanced medical knowledge. Hyperuricemia is no exception, with 28 loci identified. However, genetic control of pathways determining gout in the presence of hyperuricemia is still poorly understood. Two important pathways determining hyperuricemia have been confirmed (renal and gut excretion of uric acid with glycolysis now firmly implicated). Major urate loci are SLC2A9 and ABCG2. Recent studies show that SLC2A9 is involved in renal and gut excretion of uric acid and is implicated in antioxidant defense. Although etiological variants at SLC2A9 are yet to be identified, it is clear that considerable genetic complexity exists at the SLC2A9 locus, with multiple statistically independent genetic variants and local epistatic interactions. The positions of implicated genetic variants within or near chromatin regions involved in transcriptional control suggest that this mechanism (rather than structural changes in SLC2A9) is important in regulating the activity of SLC2A9. ABCG2 is involved primarily in extra-renal uric acid under-excretion with the etiological variant influencing expression. At the other 26 loci, probable causal genes can be identified at three (PDZK1, SLC22A11, and INHBB) with strong candidates at a further 10 loci. Confirmation of the causal gene will require a combination of re-sequencing, trans-ancestral mapping, and correlation of genetic association data with expression data. As expected, the urate loci associate with gout, although inconsistent effect sizes for gout require investigation. Finally, there has been no genome-wide association study using clinically ascertained cases to investigate the causes of gout in the presence of hyperuricemia. In such a study, use of asymptomatic hyperurcemic controls would be expected to increase the ability to detect genetic associations with gout.
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Affiliation(s)
- Tony R Merriman
- Department of Biochemistry, University of Otago, Box 56, Dunedin, 9054, New Zealand.
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32
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Wen CC, Yee SW, Liang X, Hoffmann TJ, Kvale MN, Banda Y, Jorgenson E, Schaefer C, Risch N, Giacomini KM. Genome-wide association study identifies ABCG2 (BCRP) as an allopurinol transporter and a determinant of drug response. Clin Pharmacol Ther 2015; 97:518-25. [PMID: 25676789 DOI: 10.1002/cpt.89] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 02/03/2015] [Indexed: 12/11/2022]
Abstract
The first-line treatment of hyperuricemia, which causes gout, is allopurinol. The allopurinol response is highly variable, with many users failing to achieve target serum uric acid (SUA) levels. No genome-wide association study (GWAS) has examined the genetic factors affecting allopurinol effectiveness. Using 2,027 subjects in Kaiser Permanente's Genetic Epidemiology Research on Adult Health and Aging (GERA) Cohort, we conducted a GWAS of allopurinol-related SUA reduction, first in the largest ethnic group, non-Hispanic white (NHW) subjects, and then in a stratified transethnic meta-analysis. ABCG2, encoding the efflux pump BCRP, was associated with SUA reduction in NHW subjects (P = 2 × 10(-8) ), and a missense allele (rs2231142) was associated with a reduced response (P = 3 × 10(-7) ) in the meta-analysis. Isotopic uptake studies in cells demonstrated that BCRP transports allopurinol and genetic variants in ABCG2 affect this transport. Collectively, this first GWAS of allopurinol response demonstrates that ABCG2 is a key determinant of response to the drug.
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Affiliation(s)
- C C Wen
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California, USA
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33
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Renal clearance of uric acid is linked to insulin resistance and lower excretion of sodium in gout patients. Rheumatol Int 2015; 35:1519-24. [PMID: 25763991 DOI: 10.1007/s00296-015-3242-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 03/03/2015] [Indexed: 10/23/2022]
Abstract
Inefficient renal excretion of uric acid is the main pathophysiological mechanism for hyperuricemia in gout patients. Polymorphisms of renal tubular transporters linked with sodium and monosaccharide transport have yet to be demonstrated. We intended to evaluate the impact of insulin resistance, evaluated with the homeostasis model assessment (HOMA), through a transversal study of non-diabetic patients with gout, with normal renal function, not treated with any medication but colchicine as prophylaxis. One hundred and thirty-three patients were evaluated. Clearance of uric acid was inversely correlated with insulin resistance and directly correlated with fractional excretion of sodium. In multivariate analysis, hypertension and hyperlipidemia, in addition to insulin resistance and fractional excretion of sodium, were associated with renal clearance of uric acid. HOMA cutoff for efficient versus inefficient renal handling of uric acid was 2.72, close to that observed in studies of reference population. The impact of insulin resistance and renal handling of sodium on renal clearance of uric acid may help to explain why hyperuricemia is more commonly associated with diabetes and hypertension.
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34
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Affiliation(s)
- Asim K. Mandal
- Renal Divisions, Brigham and Women's Hospital and VA Boston Healthcare System, Harvard Medical School, Boston, Massachusetts 02115;
| | - David B. Mount
- Renal Divisions, Brigham and Women's Hospital and VA Boston Healthcare System, Harvard Medical School, Boston, Massachusetts 02115;
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35
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Laston SL, Voruganti VS, Haack K, Shah VO, Bobelu A, Bobelu J, Ghahate D, Harford AM, Paine SS, Tentori F, Cole SA, MacCluer JW, Comuzzie AG, Zager PG. Genetics of kidney disease and related cardiometabolic phenotypes in Zuni Indians: the Zuni Kidney Project. Front Genet 2015; 6:6. [PMID: 25688259 PMCID: PMC4311707 DOI: 10.3389/fgene.2015.00006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 01/08/2015] [Indexed: 12/31/2022] Open
Abstract
The objective of this study is to identify genetic factors associated with chronic kidney disease (CKD) and related cardiometabolic phenotypes among participants of the Genetics of Kidney Disease in Zuni Indians study. The study was conducted as a community-based participatory research project in the Zuni Indians, a small endogamous tribe in rural New Mexico. We recruited 998 members from 28 extended multigenerational families, ascertained through probands with CKD who had at least one sibling with CKD. We used the Illumina Infinium Human1M-Duo version 3.0 BeadChips to type 1.1 million single nucleotide polymorphisms (SNPs). Prevalence estimates for CKD, hyperuricemia, diabetes, and hypertension were 24%, 30%, 17% and 34%, respectively. We found a significant (p < 1.58 × 10-7) association for a SNP in a novel gene for serum creatinine (PTPLAD2). We replicated significant associations for genes with serum uric acid (SLC2A9), triglyceride levels (APOA1, BUD13, ZNF259), and total cholesterol (PVRL2). We found novel suggestive associations (p < 1.58 × 10-6) for SNPs in genes with systolic (OLFML2B), and diastolic blood pressure (NFIA). We identified a series of genes associated with CKD and related cardiometabolic phenotypes among Zuni Indians, a population with a high prevalence of kidney disease. Illuminating genetic variations that modulate the risk for these disorders may ultimately provide a basis for novel preventive strategies and therapeutic interventions.
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Affiliation(s)
- Sandra L Laston
- South Texas Diabetes and Obesity Institute, Regional Academic Health Center, University of Texas at San Antonio Harlingen, TX, USA
| | - V Saroja Voruganti
- Department of Nutrition, University of North Carolina at Chapel Hill Kannapolis, NC, USA ; University of North Carolina Nutrition Research Institute, University of North Carolina at Chapel Hill Kannapolis, NC, USA
| | - Karin Haack
- Department of Genetics, Texas Biomedical Research Institute San Antonio, TX, USA
| | - Vallabh O Shah
- Department of Biochemistry, University of New Mexico School of Medicine Albuquerque, NM, USA
| | - Arlene Bobelu
- Department of Biochemistry, University of New Mexico School of Medicine Albuquerque, NM, USA
| | - Jeanette Bobelu
- Department of Biochemistry, University of New Mexico School of Medicine Albuquerque, NM, USA
| | - Donica Ghahate
- Department of Biochemistry, University of New Mexico School of Medicine Albuquerque, NM, USA
| | - Antonia M Harford
- Department of Biochemistry, University of New Mexico School of Medicine Albuquerque, NM, USA
| | | | | | - Shelley A Cole
- Department of Genetics, Texas Biomedical Research Institute San Antonio, TX, USA
| | - Jean W MacCluer
- Department of Genetics, Texas Biomedical Research Institute San Antonio, TX, USA
| | - Anthony G Comuzzie
- Department of Genetics, Texas Biomedical Research Institute San Antonio, TX, USA ; Southwest National Primate Research Center San Antonio, TX, USA
| | - Philip G Zager
- Dialysis Clinic, Inc., Albuquerque, NM USA ; Department of Medicine, Division of Nephrology, University of New Mexico School of Medicine Albuquerque, NM, USA
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Szarka A, Balogh T. In silico aided thoughts on mitochondrial vitamin C transport. J Theor Biol 2014; 365:181-9. [PMID: 25451960 DOI: 10.1016/j.jtbi.2014.10.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 10/01/2014] [Accepted: 10/13/2014] [Indexed: 01/20/2023]
Abstract
The huge demand of mitochondria as the quantitatively most important sources of ROS in the majority of heterotrophic cells for vitamin C is indisputable. The reduced form of the vitamin, l-ascorbic acid, is imported by an active mechanism requiring two sodium-dependent vitamin C transporters (SVCT1 and SVCT2). The oxidized form, dehydroascorbate is taken up by different members of the GLUT family. Because of the controversial experimental results the picture on mitochondrial vitamin C transport became quite obscure by the spring of 2014. Thus in silico prediction tools were applied in aid of the support of in vitro and in vivo results. The role of GLUT1 as a mitochondrial dehydroascorbate transporter could be reinforced by in silico predictions however the mitochondrial presence of GLUT10 is not likely since this transport protein got far the lowest mitochondrial localization scores. Furthermore the possible roles of GLUT9 and 11 in mitochondrial vitamin C transport can be proposed leastwise on the base of their computational localization analysis. In good concordance with the newest experimental observations on SVCT2 the mitochondrial presence of this transporter could also be supported by the computational prediction tools.
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Affiliation(s)
- András Szarka
- Department of Applied Biotechnology and Food Science, Laboratory of Biochemistry and Molecular Biology, Budapest University of Technology and Economics, 1111 Szent Gellért tér 4, Budapest, Hungary; Pathobiochemistry Research Group of Hungarian Academy of Sciences and Semmelweis University, 1444 Budapest, PO Box 260, Budapest, Hungary.
| | - Tibor Balogh
- Department of Applied Biotechnology and Food Science, Laboratory of Biochemistry and Molecular Biology, Budapest University of Technology and Economics, 1111 Szent Gellért tér 4, Budapest, Hungary
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Chino Y, Samukawa Y, Sakai S, Nakai Y, Yamaguchi JI, Nakanishi T, Tamai I. SGLT2 inhibitor lowers serum uric acid through alteration of uric acid transport activity in renal tubule by increased glycosuria. Biopharm Drug Dispos 2014; 35:391-404. [PMID: 25044127 PMCID: PMC4223977 DOI: 10.1002/bdd.1909] [Citation(s) in RCA: 242] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 06/24/2014] [Accepted: 07/01/2014] [Indexed: 12/13/2022]
Abstract
Sodium glucose cotransporter 2 (SGLT2) inhibitors have been reported to lower the serum uric acid (SUA) level. To elucidate the mechanism responsible for this reduction, SUA and the urinary excretion rate of uric acid (UE(UA)) were analysed after the oral administration of luseogliflozin, a SGLT2 inhibitor, to healthy subjects. After dosing, SUA decreased, and a negative correlation was observed between the SUA level and the UE(UA), suggesting that SUA decreased as a result of the increase in the UE(UA). The increase in UE(UA) was correlated with an increase in urinary D-glucose excretion, but not with the plasma luseogliflozin concentration. Additionally, in vitro transport experiments showed that luseogliflozin had no direct effect on the transporters involved in renal UA reabsorption. To explain that the increase in UE(UA) is likely due to glycosuria, the study focused on the facilitative glucose transporter 9 isoform 2 (GLUT9ΔN, SLC2A9b), which is expressed at the apical membrane of the kidney tubular cells and transports both UA and D-glucose. It was observed that the efflux of [(14) C]UA in Xenopus oocytes expressing the GLUT9 isoform 2 was trans-stimulated by 10 mm D-glucose, a high concentration of glucose that existed under SGLT2 inhibition. On the other hand, the uptake of [(14) C]UA by oocytes was cis-inhibited by 100 mm D-glucose, a concentration assumed to exist in collecting ducts. In conclusion, it was demonstrated that the UE(UA) could potentially be increased by luseogliflozin-induced glycosuria, with alterations of UA transport activity because of urinary glucose.
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Affiliation(s)
- Yukihiro Chino
- Department of Membrane Transport and Biopharmaceutics, Faculty of Pharmaceutical Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa UniversityKakuma-machi, Kanazawa, 920-1192, Japan
- Drug Safety and Pharmacokinetics Laboratories, Taisho Pharmaceutical Co., Ltd1-403 Yoshino-cho, Kita-ku, Saitama, 331-9530, Japan
| | - Yoshishige Samukawa
- Development Management, Taisho Pharmaceutical Co., Ltd3-24-1, Takada, Toshima-ku, Tokyo, 170-8633, Japan
| | - Soichi Sakai
- Clinical Research, Taisho Pharmaceutical Co., Ltd3-24-1, Takada, Toshima-ku, Tokyo, 170-8633, Japan
| | - Yasuhiro Nakai
- Development Management, Taisho Pharmaceutical Co., Ltd3-24-1, Takada, Toshima-ku, Tokyo, 170-8633, Japan
| | - Jun-ichi Yamaguchi
- Drug Safety and Pharmacokinetics Laboratories, Taisho Pharmaceutical Co., Ltd1-403 Yoshino-cho, Kita-ku, Saitama, 331-9530, Japan
| | - Takeo Nakanishi
- Department of Membrane Transport and Biopharmaceutics, Faculty of Pharmaceutical Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa UniversityKakuma-machi, Kanazawa, 920-1192, Japan
| | - Ikumi Tamai
- Department of Membrane Transport and Biopharmaceutics, Faculty of Pharmaceutical Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa UniversityKakuma-machi, Kanazawa, 920-1192, Japan
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Rasheed H, Hughes K, Flynn TJ, Merriman TR. Mendelian randomization provides no evidence for a causal role of serum urate in increasing serum triglyceride levels. ACTA ACUST UNITED AC 2014; 7:830-7. [PMID: 25249548 DOI: 10.1161/circgenetics.114.000556] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Triglycerides and their lipoprotein transport molecules are risk factors for heart disease. Observational studies have associated elevated levels of serum urate (SU) with triglycerides and risk of heart disease. However, owing to unmeasured confounding, observational studies do not provide insight into the causal relationship between SU and triglyceride. The aim of this study was to test for a causal role of SU in increasing triglyceride using Mendelian randomization that accounts for unmeasured confounding. METHODS AND RESULTS Subjects were of European ancestry from the atherosclerosis risk in communities (n=5237) and Framingham heart (n=2971) studies. Mendelian randomization by the 2-stage least squares regression method was done with SU as the exposure, a uric acid transporter genetic risk score as instrumental variable, and triglyceride as the outcome. In ordinary linear regression, SU was significantly associated with triglyceride levels (β=2.69 mmol/L change in triglyceride per mmol/L increase in SU). However, Mendelian randomization-based estimation showed no evidence for a direct causal association of SU with triglyceride concentration-there was a nonsignificant 1.01 mmol/L decrease in triglyceride per mmol/L increase in SU attributable to the genetic risk score (P=0.21). The reverse analysis using a triglyceride genetic risk score provided evidence of a causal role for triglyceride in raising urate in men (P(Corrected)=0.018). CONCLUSIONS These data provide no evidence for a causal role for SU in raising triglyceride levels, consistent with a previous Mendelian randomization report of no association between SU and ischemic heart disease.
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Affiliation(s)
- Humaira Rasheed
- From the Department of Chemistry, University of Engineering and Technology, Lahore, Pakistan (H.R.); and Department of Biochemistry, University of Otago, Dunedin, New Zealand (K.H., T.J.F., T.R.M.)
| | - Kim Hughes
- From the Department of Chemistry, University of Engineering and Technology, Lahore, Pakistan (H.R.); and Department of Biochemistry, University of Otago, Dunedin, New Zealand (K.H., T.J.F., T.R.M.)
| | - Tanya J Flynn
- From the Department of Chemistry, University of Engineering and Technology, Lahore, Pakistan (H.R.); and Department of Biochemistry, University of Otago, Dunedin, New Zealand (K.H., T.J.F., T.R.M.)
| | - Tony R Merriman
- From the Department of Chemistry, University of Engineering and Technology, Lahore, Pakistan (H.R.); and Department of Biochemistry, University of Otago, Dunedin, New Zealand (K.H., T.J.F., T.R.M.).
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Prestin K, Wolf S, Feldtmann R, Hussner J, Geissler I, Rimmbach C, Kroemer HK, Zimmermann U, Meyer zu Schwabedissen HE. Transcriptional regulation of urate transportosome member SLC2A9 by nuclear receptor HNF4α. Am J Physiol Renal Physiol 2014; 307:F1041-51. [PMID: 25209865 DOI: 10.1152/ajprenal.00640.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Renal tubular handling of urate is realized by a network of uptake and efflux transporters, including members of drug transporter families such as solute carrier proteins and ATP-binding cassette transporters. Solute carrier family 2, member 9 (SLC2A9), is one key factor of this so called "urate transportosome." The aim of the present study was to understand the transcriptional regulation of SLC2A9 and to test whether identified factors might contribute to a coordinated transcriptional regulation of the transporters involved in urate handling. In silico analysis and cell-based reporter gene assays identified a hepatocyte nuclear factor (HNF)4α-binding site in the promoter of SLC2A9 isoform 1, whose activity was enhanced by transient HNF4α overexpression, whereas mutation of the binding site diminished activation. HNF4α overexpression induced endogenous SLC2A9 expression in vitro. The in vivo role of HNF4α in the modulation of renal SLC2A9 gene expression was supported by findings of quantitative real-time RT-PCR analyses and chromatin immunoprecipitation assays. Indeed, mRNA expression of SLC2A9 and HNF4α in human kidney samples was significantly correlated. We also showed that in renal clear cell carcinoma, downregulation of HNF4α mRNA and protein expression was associated with a significant decline in expression of the transporter. Taken together, our data suggest that nuclear receptor family member HNF4α contributes to the transcriptional regulation of SLC2A9 isoform 1. Since HNF4α has previously been assumed to be a modulator of several urate transporters, our findings support the notion that there could be a transcriptional network providing synchronized regulation of the functional network of the urate transportosome.
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Affiliation(s)
- Katharina Prestin
- University of Basel, Department of Pharmaceutical Sciences, Biopharmacy, Basel, Switzerland
| | - Stephanie Wolf
- University Medicine, Ernst Moritz Arndt University Greifswald, Center of Drug Absorption and Transport, Institute of Pharmacology, Greifswald, Germany
| | - Rico Feldtmann
- University Medicine, Ernst Moritz Arndt University Greifswald, Center of Drug Absorption and Transport, Institute of Pharmacology, Greifswald, Germany
| | - Janine Hussner
- University of Basel, Department of Pharmaceutical Sciences, Biopharmacy, Basel, Switzerland
| | - Ingrid Geissler
- University Medicine, Ernst Moritz Arndt University Greifswald, Center of Drug Absorption and Transport, Institute of Pharmacology, Greifswald, Germany
| | - Christian Rimmbach
- University Medicine, Ernst Moritz Arndt University Greifswald, Center of Drug Absorption and Transport, Institute of Pharmacology, Greifswald, Germany
| | - Heyo K Kroemer
- University of Goettingen, Medical Faculty, Goettingen, Germany; and
| | - Uwe Zimmermann
- University Medicine, Ernst Moritz Arndt University Greifswald, Department of Urology, Greifswald, Germany
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Abstract
PURPOSE OF REVIEW Recent advances in genome technology have provided us with a list of molecules affecting urate handling in humans, many of which are unlikely to be identified through traditional physiological approach alone. Although this article is focused on urate, this can be viewed as a successful model of genomics-physiology collaboration. RECENT FINDINGS URATv1/GLUT9 (SLC2A9) is shown to play a critical role in urate reabsorption at the proximal tubule, probably more prominent than its partner URAT1 (SLC22A12). The major site of action of ABCG2 (ABCG2), an influential urate secretion transporter, has been shown to be the intestine rather than the kidney proximal tubule. Accordingly, hypofunction of ABCG2 leads to increased fractional excretion of urate, a finding traditionally interpreted as overproduction hyperuricemia. Some SLC17 family members secrete urate in the kidney or intestine. OAT2 (SLC22A7) may take up urate from blood to the proximal tubular cell. In addition, how a common single-nucleotide polymorphisms in ABCG2 affects its function has been elucidated. SUMMARY A finer grained picture of urate handling in the human body is now emerging, which will help choosing novel targets for urate-lowering therapy.
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Kimura T, Takahashi M, Yan K, Sakurai H. Expression of SLC2A9 isoforms in the kidney and their localization in polarized epithelial cells. PLoS One 2014; 9:e84996. [PMID: 24409316 PMCID: PMC3883675 DOI: 10.1371/journal.pone.0084996] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 11/27/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Many genome-wide association studies pointed out that SLC2A9 gene, which encodes a voltage-driven urate transporter, SLC2A9/GLUT9 (a.k.a. URATv1), as one of the most influential genes for serum urate levels. SLC2A9 is reported to encode two splice variants: SLC2A9-S (512 amino acids) and SLC2A9-L (540 amino acids), only difference being at their N-termini. We investigated isoform-specific localization of SLC2A9 in the human kidney and role of N-terminal amino acids in differential sorting in vitro. METHODOLOGY/PRINCIPAL FINDINGS Isoform specific antibodies against SLC2A9 were developed and human kidney sections were stained. SLC2A9-S was expressed in the apical side of the collecting duct while SLC2A9-L was expressed in the basolateral side of the proximal tubule. GFP fused SLC2A9s were expressed in MDCK cells and intracellular localization was observed. SLC2A9-S was expressed at both apical and basolateral membranes, whereas SLC2A9-L was expressed only at the basolateral membrane. Although SLC2A9-L has a putative di-leucine motif at 33th and 34th leucine, deletion of the motif or replacement of leucine did not affect its subcellular localization. When up to 16 amino acids were removed from the N-terminal of SLC2A9-S or when up to 25 amino acids were removed from the N-terminal of SLC2A9-L, there was no change in their sorting. Deletion of 20 amino acids from SLC2A9-S was not expressed in the cell. More than 30 amino acids deletion from SLC2A9-L resulted in expression at both apical and basolateral membranes as well as in the lysosome. When amino acids from 25th and 30th were changed to alanine in SLC2A9-L, expression pattern was the same as wild-type. CONCLUSIONS/SIGNIFICANCE SLC2A9-L was expressed in the basolateral membrane of kidney proximal tubules in humans and this isoform is likely to responsible for urate reabsorption. N-terminal amino acids unique to each isoform played an important role in protein stability and trafficking.
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Affiliation(s)
- Toru Kimura
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Michi Takahashi
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Kunimasa Yan
- Department of Pediatrics, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Hiroyuki Sakurai
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
- * E-mail:
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Gilbert RE. Sodium-glucose linked transporter-2 inhibitors: potential for renoprotection beyond blood glucose lowering? Kidney Int 2013; 86:693-700. [PMID: 24257692 DOI: 10.1038/ki.2013.451] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 09/09/2013] [Accepted: 09/12/2013] [Indexed: 01/10/2023]
Abstract
The proximal tubule's sodium-glucose linked transporter-2 (SGLT2) accounts for the vast majority of glucose reabsorption by the kidney. Its selective inhibition, accordingly, leads to substantial glycosuria, lowering blood glucose, and facilitating weight loss in individuals with diabetes. During the past year, two SGLT2 inhibitors, canagliflozin and dapagliflozin, have been approved for the treatment of type 2 diabetes. Beyond their anti-hyperglycemic properties, however, this new class of drugs has several other attributes that provide a theoretical basis for kidney protection. Like agents that block the renin-angiotensin system, SGLT2 inhibitors also reduce single-nephron glomerular filtration rate (SNGFR) in the chronically diseased kidney, though by quite different mechanisms. Additional potentially beneficial effects of SGLT2 inhibition include modest reductions in blood pressure and plasma uric acid. Finally, cell culture studies indicate that glucose uptake from the tubular lumen, as well as from the basolateral compartment, can contribute to proximal tubular production of extracellular matrix proteins. Whether such attributes will translate into reducing the progression of chronic kidney disease will require the undertaking of long-term, dedicated studies.
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Affiliation(s)
- Richard E Gilbert
- Division of Endocrinology, Department of Medicine, University of Toronto, St Michael's Hospital, Li Ka Shing Knowledge Institute, Toronto, Ontario, Canada
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Batt C, Phipps-Green AJ, Black MA, Cadzow M, Merriman ME, Topless R, Gow P, Harrison A, Highton J, Jones P, Stamp L, Dalbeth N, Merriman TR. Sugar-sweetened beverage consumption: a risk factor for prevalent gout with SLC2A9 genotype-specific effects on serum urate and risk of gout. Ann Rheum Dis 2013; 73:2101-6. [PMID: 24026676 PMCID: PMC4251167 DOI: 10.1136/annrheumdis-2013-203600] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Objective Consumption of high fructose corn syrup (HFCS)-sweetened beverages increases serum urate and risk of incident gout. Genetic variants in SLC2A9, that exchanges uric acid for glucose and fructose, associate with gout. We tested association between sugar (sucrose)-sweetened beverage (SSB) consumption and prevalent gout. We also tested the hypothesis that SLC2A9 genotype and SSB consumption interact to determine gout risk. Methods Participants were 1634 New Zealand (NZ) European Caucasian, Ma¯ori and Pacific Island people and 7075 European Caucasians from the Atherosclerosis Risk in Communities (ARIC) study. NZ samples were genotyped for rs11942223 and ARIC for rs6449173. Effect estimates were multivariate adjusted. Results SSB consumption increased gout risk. The OR for four drinks/day relative to zero was 6.89 (p=0.045), 5.19 (p=0.010) and 2.84 (p=0.043) for European Caucasian, Ma¯ori and Pacific Islanders, respectively. With each extra daily SSB serving, carriage of the gout-protective allele of SLC2A9 associated with a 15% increase in risk (p=0.078), compared with a 12% increase in non-carriers (p=0.002). The interaction term was significant in pooled (pInteraction=0.01) but not meta-analysed (pInteraction=0.99) data. In ARIC, with each extra daily serving, a greater increase in serum urate protective allele carriers (0.005 (p=8.7×10−5) compared with 0.002 (p=0.016) mmol/L) supported the gout data (pInteraction=0.062). Conclusions Association of SSB consumption with prevalent gout supports reduction of SSB in management. The interaction data suggest that SLC2A9-mediated renal uric acid excretion is physiologically influenced by intake of simple sugars derived from SSB, with SSB exposure negating the gout risk discrimination of SLC2A9.
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Affiliation(s)
- Caitlin Batt
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | | | - Michael A Black
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Murray Cadzow
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | | | - Ruth Topless
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Peter Gow
- Department of Rheumatology, Middlemore Hospital, Auckland, New Zealand
| | - Andrew Harrison
- Department of Medicine, University of Otago, Wellington, New Zealand
| | - John Highton
- Department of Medicine, University of Otago, Dunedin, New Zealand
| | - Peter Jones
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Lisa Stamp
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Nicola Dalbeth
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Tony R Merriman
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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Bibee KP, Augustin R, Gazit V, Moley KH. The apical sorting signal for human GLUT9b resides in the N-terminus. Mol Cell Biochem 2013; 376:163-73. [PMID: 23361362 DOI: 10.1007/s11010-013-1564-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Accepted: 01/18/2013] [Indexed: 12/11/2022]
Abstract
The two splice variants of human glucose transporter 9 (hGLUT9) are targeted to different polarized membranes. hGLUT9a traffics to the basolateral membrane, whereas hGLUT9b traffics to the apical region. This study examines the sorting mechanism of these variants, which differ only in their N-terminal domain. Mutating a di-leucine motif unique to GLUT9a did not affect targeting. Chimeric proteins were made using GLUT1, a basolaterally targeted transporter, and GLUT3, an apically targeted protein whose signal lies in the C-terminus. Overexpression of the chimeric proteins in polarized cells demonstrates that the N-terminus of hGLUT9b contains a signal capable of redirecting GLUT1 to the apical membrane. The N-terminus of hGLUT9a, however, does not contain a basolateral signal sufficient enough to redirect GLUT3. Portions of the GLUT9a N-terminus were substituted with corresponding portions of the GLUT9b N-terminus to determine the motif responsible for apical targeting. The first 16 amino acids were not found to be a sufficient apical signal. The last ten amino acids of the N-termini differ only in amino-acid class at one location. In the B-form, leucine, a hydrophobic residue, is substituted for lysine, a basic residue, found in the A-form. However, mutation of the leucine in hGLUT9b to a lysine resulted in retention of the apical signal. We therefore believe the apical signal exists as an interplay between the final ten amino acids of the N-terminus and another motif within the protein such as the intracellular loop or other motifs within the N-terminus.
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Affiliation(s)
- Kristin P Bibee
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA
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The facilitative glucose transporter GLUT12: what do we know and what would we like to know? J Physiol Biochem 2012; 69:325-33. [DOI: 10.1007/s13105-012-0213-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 09/12/2012] [Indexed: 12/22/2022]
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