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Xu B, Li S, Kang B, Fan S, Chen C, Li W, Chen J, He Z, Tang F, Zhou J. Role of SLC5A2 polymorphisms and effects of genetic polymorphism on sodium glucose cotransporter 2 inhibitorsinhibitor response. Mol Biol Rep 2023; 50:9637-9647. [PMID: 37819499 DOI: 10.1007/s11033-023-08836-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
Type 2 diabetes mellitus (T2DM) is a complex metabolic disease characterized by hyperglycaemia. T2DM is a highly heterogeneous polygenic disease. Due to genetic variation, variations in lifestyle and other environmental exposures, there are certain variations in the phenotype of T2DM patients. Sodium glucose cotransporter 2 (SGLT2) inhibitors are novel hypoglycaemic agents that increase urinary glucose excretion by inhibiting glucose reabsorption in the proximal tubules of the kidney. For glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, studies have confirmed a variety of gene variants that may modify their effects. For SGLT2 inhibitors, research has focused on the SLC5A2 gene encoding SGLT2 and UGT1A9 gene polymorphisms affecting SGLT2 inhibitor metabolism. The SLC5A2 polymorphism rs9934336 have been associated with decreased HbA1c during the oral glucose tolerance test. Common variants of the SLC5A2 gene are related to blood glucose and insulin concentrations, but not glucagon concentrations. SLC5A2 rs9934336 and rs3116150 are related to a lower risk of heart failure. SGLT2 inhibitor exposure of UGT1A9*3 carriers is commonly higher than that of noncarriers, while these effects commonly have no obvious clinical significance on SGLT2 inhibitor pharmacokinetics. In terms of efficacy, general SLC5A2 variants show no significant effect on the response to the SGLT2 inhibitor empagliflozin. At present, research on the relationship between genetic polymorphisms and the efficacy of SGLT2 inhibitors is limited. The main purpose of this review is to elucidate the general effects of SGLT2 polymorphisms and the association between polymorphisms and the treatment response to SGLT2 inhibitors.
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Affiliation(s)
- Bo Xu
- The First Affiliated Hospital, Hengyang Clinical Pharmacology Research Center, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Hengyang Key Laboratory of Clinical Pharmacology, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Pharmacy Department, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Shaoqian Li
- The First Affiliated Hospital, Hengyang Clinical Pharmacology Research Center, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Hengyang Key Laboratory of Clinical Pharmacology, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Pharmacy Department, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Bo Kang
- The First Affiliated Hospital, Hengyang Clinical Pharmacology Research Center, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Hengyang Key Laboratory of Clinical Pharmacology, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Pharmacy Department, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Shangzhi Fan
- The First Affiliated Hospital, Hengyang Clinical Pharmacology Research Center, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Hengyang Key Laboratory of Clinical Pharmacology, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Pharmacy Department, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Canyu Chen
- The First Affiliated Hospital, Hengyang Clinical Pharmacology Research Center, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Hengyang Key Laboratory of Clinical Pharmacology, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Pharmacy Department, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Weiyi Li
- The First Affiliated Hospital, Hengyang Clinical Pharmacology Research Center, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Hengyang Key Laboratory of Clinical Pharmacology, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Pharmacy Department, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Jixiang Chen
- The First Affiliated Hospital, Hengyang Clinical Pharmacology Research Center, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Hengyang Key Laboratory of Clinical Pharmacology, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Pharmacy Department, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Zunbo He
- The First Affiliated Hospital, Hengyang Clinical Pharmacology Research Center, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Hengyang Key Laboratory of Clinical Pharmacology, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Pharmacy Department, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Fan Tang
- The First Affiliated Hospital, Hengyang Clinical Pharmacology Research Center, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Hengyang Key Laboratory of Clinical Pharmacology, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
- The First Affiliated Hospital, Pharmacy Department, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Jiecan Zhou
- The First Affiliated Hospital, Hengyang Clinical Pharmacology Research Center, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
- The First Affiliated Hospital, Hengyang Key Laboratory of Clinical Pharmacology, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
- The First Affiliated Hospital, Pharmacy Department, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
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Grünert SC, Schumann A, Baronio F, Tsiakas K, Murko S, Spiekerkoetter U, Santer R. Evidence for a Genotype-Phenotype Correlation in Patients with Pathogenic GLUT2 ( SLC2A2) Variants. Genes (Basel) 2021; 12:genes12111785. [PMID: 34828390 PMCID: PMC8622088 DOI: 10.3390/genes12111785] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 11/04/2021] [Indexed: 02/06/2023] Open
Abstract
Fanconi-Bickel syndrome (FBS) is a very rare but distinct clinical entity with the combined features of hepatic glycogen storage disease, generalized proximal renal tubular dysfunction with disproportionately severe glucosuria, and impaired galactose tolerance. Here, we report five cases (out of 93 diagnosed in our lab) with pathogenic variants on both GLUT2 (SLC2A2) alleles. They come from 3 families and presented with an exceptionally mild clinical course. This course was correlated to data from old and most recent expression and transport studies in Xenopus oocytes. GLUT2 genotype in patients 1 and 2 was p.[153_4delLI];[P417R] with the first variant exhibiting normal membrane expression and partially retained transport activity (5.8%) for 2-deoxyglucose. In patient 3, the very first GLUT2 variant ever detected (p.V197I) was found, but for the first time it was present in a patient in the homozygous state. This variant had also shown unaffected membrane expression and remarkable residual activity (8%). The genotype in patient 4, p.[153_4delLI];[(E440A)], again included the 2-amino-acid deletion with residual transporter function, and patient 5 is the first found to be homozygous for this variant. Our results provide further evidence for a genotype-phenotype correlation in patients with GLUT2 variants; non-functional variants result in the full picture of FBS while dysfunctional variants may result in milder presentations, even glucosuria only, without other typical signs of FBS.
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Affiliation(s)
- Sarah C. Grünert
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center—University of Freiburg, 79106 Freiburg, Germany; (A.S.); (U.S.)
- Correspondence:
| | - Anke Schumann
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center—University of Freiburg, 79106 Freiburg, Germany; (A.S.); (U.S.)
| | - Federico Baronio
- Pediatric Unit, Department of Medical and Surgical Sciences, Regional Center for Expanded Newborn Screening, S. Orsola—Malpighi University Hospital, 40138 Bologna, Italy;
| | - Konstantinos Tsiakas
- Department of Pediatrics, University Medical Center Eppendorf, 20246 Hamburg, Germany; (K.T.); (S.M.); (R.S.)
| | - Simona Murko
- Department of Pediatrics, University Medical Center Eppendorf, 20246 Hamburg, Germany; (K.T.); (S.M.); (R.S.)
| | - Ute Spiekerkoetter
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center—University of Freiburg, 79106 Freiburg, Germany; (A.S.); (U.S.)
| | - René Santer
- Department of Pediatrics, University Medical Center Eppendorf, 20246 Hamburg, Germany; (K.T.); (S.M.); (R.S.)
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3
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Monobe K, Noso S, Babaya N, Hiromine Y, Taketomo Y, Niwano F, Yoshida S, Yasutake S, Minohara T, Kawabata Y, Ikegami H. Clinical and genetic determinants of urinary glucose excretion in patients with diabetes mellitus. J Diabetes Investig 2021; 12:728-737. [PMID: 32986906 PMCID: PMC8088999 DOI: 10.1111/jdi.13417] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/17/2020] [Accepted: 09/20/2020] [Indexed: 12/04/2022] Open
Abstract
AIMS/INTRODUCTION Glucosuria is a representative symptom in diabetes patients with poor glycemic control and in those treated with sodium-glucose cotransporter 2 inhibitors. Renal threshold levels of glucose excretion are known to vary among individuals, but factors contributing to glucosuria are not well characterized. The present study aimed to clarify clinical and genetic determinants of glucosuria in individuals with diabetes mellitus. MATERIALS AND METHODS The 24-h urinary glucose excretion was measured in 135 hospitalized patients on admission, with continuous measurement for five consecutive days in 75 patients. Genetic and clinical factors contributing to glucosuria were studied. As a genetic factor, SLC5A2 polymorphism was genotyped. A total of 476 participants (266 participants with type 2 diabetes and 210 healthy controls) were additionally genotyped for the association study of SLC5A2 with type 2 diabetes. A meta-analysis was carried out with the present study and previous association studies. RESULTS Multiple regression analysis showed that the independent variables of average blood glucose (β = 0.41, P = 1.4 × 10-7 ), estimated glomerular filtration rate (β = 0.28, P = 6.0 × 10-5 ), sex (β = 0.28, P = 5.7 × 10-5 ) and SLC5A2 rs9934336 polymorphism (β = 0.17, P = 0.02) were significantly correlated with urinary glucose excretion. The frequency of the A allele of rs9934336 tended to be lower in participants with type 2 diabetes than in controls (odds ratio 0.78, 95% confidence interval 0.53-1.13, not significant), and meta-analysis showed a significant association between the A allele and type 2 diabetes (summary odds ratio for minor allele [A] 0.86, 95% confidence interval 0.78-0.94, P < 0.002). CONCLUSIONS Blood glucose, estimated glomerular filtration rate, sex and SLC5A2 polymorphism were independent determinants of glucosuria in diabetes mellitus.
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Affiliation(s)
- Keisuke Monobe
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsaka‐sayamaOsakaJapan
| | - Shinsuke Noso
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsaka‐sayamaOsakaJapan
| | - Naru Babaya
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsaka‐sayamaOsakaJapan
| | - Yoshihisa Hiromine
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsaka‐sayamaOsakaJapan
| | - Yasunori Taketomo
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsaka‐sayamaOsakaJapan
| | - Fumimaru Niwano
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsaka‐sayamaOsakaJapan
| | - Sawa Yoshida
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsaka‐sayamaOsakaJapan
| | - Sara Yasutake
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsaka‐sayamaOsakaJapan
| | - Tatsuro Minohara
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsaka‐sayamaOsakaJapan
| | - Yumiko Kawabata
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsaka‐sayamaOsakaJapan
| | - Hiroshi Ikegami
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsaka‐sayamaOsakaJapan
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Hinden L, Kogot-Levin A, Tam J, Leibowitz G. Pathogenesis of diabesity-induced kidney disease: role of kidney nutrient sensing. FEBS J 2021; 289:901-921. [PMID: 33630415 DOI: 10.1111/febs.15790] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/09/2021] [Accepted: 02/24/2021] [Indexed: 12/11/2022]
Abstract
Diabetes kidney disease (DKD) is a major healthcare problem associated with increased risk for developing end-stage kidney disease and high mortality. It is widely accepted that DKD is primarily a glomerular disease. Recent findings however suggest that kidney proximal tubule cells (KPTCs) may play a central role in the pathophysiology of DKD. In diabetes and obesity, KPTCs are exposed to nutrient overload, including glucose, free-fatty acids and amino acids, which dysregulate nutrient and energy sensing by mechanistic target of rapamycin complex 1 and AMP-activated protein kinase, with subsequent induction of tubular injury, inflammation, and fibrosis. Pharmacological treatments that modulate nutrient sensing and signaling in KPTCs, including cannabinoid-1 receptor antagonists and sodium glucose transporter 2 inhibitors, exert robust kidney protective effects. Shedding light on how nutrients are sensed and metabolized in KPTCs and in other kidney domains, and on their effects on signal transduction pathways that mediate kidney injury, is important for understanding the pathophysiology of DKD and for the development of novel therapeutic approaches in DKD and probably also in other forms of kidney disease.
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Affiliation(s)
- Liad Hinden
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Aviram Kogot-Levin
- Diabetes Unit and Endocrine Service, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Joseph Tam
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Gil Leibowitz
- Diabetes Unit and Endocrine Service, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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5
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Akhoon N. Precision Medicine: A New Paradigm in Therapeutics. Int J Prev Med 2021; 12:12. [PMID: 34084309 PMCID: PMC8106271 DOI: 10.4103/ijpvm.ijpvm_375_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 02/04/2020] [Indexed: 11/26/2022] Open
Abstract
A key goal of clinical care is to treat patients as individuals and to approach therapeutics in such a way that it has optimal efficacy and minimal toxicity. With swift technological advances, such as genomic sequencing and molecular targeted drug exploitation, the concept of precision medicine has been robustly promoted in recent years. Precision medicine endeavors to demarcate diseases using multiple data sources from genomics to digital health metrics in order to facilitate an individualized yet "evidence-based" decision regarding diagnostic and therapeutic approaches. In this way, therapeutics can be centered toward patients based on their molecular presentation rather than grouping them into broad categories with a "one size fits all" approach. This review article is aimed to provide a broad overview of the advent and emergence of precision medicine in view of its current implications.
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Affiliation(s)
- Neha Akhoon
- Department of Pharmacology, Armed Forces Medical College, Pune, Maharashtra, India
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6
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Feng X, Zheng Y, Guan H, Zhou X, Xu Y, Zhang X, Fu C, Xiao J, Ye Z. The Association between Urinary Glucose and Renal Uric Acid Excretion in Non-diabetic Patients with Stage 1-2 Chronic Kidney Disease. Endocr Res 2021; 46:28-36. [PMID: 33245244 DOI: 10.1080/07435800.2020.1850760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Aims: To test the hypothesis that in non-diabetic patients with early-stage chronic kidney disease (CKD), the renal excretion of urate and glucose transportation are coupled and interconnected. Methods: A cross-sectional study of 255 non-diabetic participants with stage 1-2 CKD recruited from our department was conducted. Spearman's correlation and multiple linear regression analyses were used to study the correlation between urinary glucose and renal uric acid excretion. ANOVA was used to compare urinary uric acid excretion among three tertiles of urinary glucose (UG; UG1: UG<0.24 mmol/24 h/1.73 m2, UG2: 0.24 mmol/24 h/1.73 m2≤ UG≤0.55 mmol/24 h/1.73 m2, and UG3: UG>0.55 mmol/24 h/1.73 m2), the fractional excretion of glucose (FEG; FEG1: FEG<0.04%, FEG2: 0.04%≤FEG≤0.09%, and FEG3: FEG>0.09%) and the excretion of glucose per volume of glomerular filtration (EgGF; EgGF1: EgGF<1.95 μmol/L, EgGF2: 1.95 μmol/L≤ EgGF≤3.99 μmol/L, and EgGF3: EgGF>3.99 μmol/L). Results: According to the multiple linear regression analysis, FEG and EgGF were positively correlated with the excretion of uric acid per volume of glomerular filtration (EurGF) after adjusting for confounding factors. The EurGF levels in the highest tertiles of UG, FEG and EgGF were higher than those in the lowest tertiles of UG, FEG and EgGF. Conclusion: Urinary glucose excretion is closely related to renal excretion of uric acid in non-diabetic patients with stage 1-2 CKD.
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Affiliation(s)
- Xinhui Feng
- Department of Nephrology, Huadong Hospital Affiliated to Fudan University , Shanghai, P.R. China
- Shanghai Key Laboratory of Clinical Geriatric Medicine , Shanghai, P.R. China
| | - Yuqi Zheng
- Department of Nephrology, Huadong Hospital Affiliated to Fudan University , Shanghai, P.R. China
- Shanghai Key Laboratory of Clinical Geriatric Medicine , Shanghai, P.R. China
| | - Haochen Guan
- Department of Nephrology, Huadong Hospital Affiliated to Fudan University , Shanghai, P.R. China
- Shanghai Key Laboratory of Clinical Geriatric Medicine , Shanghai, P.R. China
| | - Xun Zhou
- Department of Nephrology, Huadong Hospital Affiliated to Fudan University , Shanghai, P.R. China
- Shanghai Key Laboratory of Clinical Geriatric Medicine , Shanghai, P.R. China
| | - Ying Xu
- Department of Nephrology, Huadong Hospital Affiliated to Fudan University , Shanghai, P.R. China
- Shanghai Key Laboratory of Clinical Geriatric Medicine , Shanghai, P.R. China
| | - Xiaoli Zhang
- Department of Nephrology, Huadong Hospital Affiliated to Fudan University , Shanghai, P.R. China
- Shanghai Key Laboratory of Clinical Geriatric Medicine , Shanghai, P.R. China
| | - Chensheng Fu
- Department of Nephrology, Huadong Hospital Affiliated to Fudan University , Shanghai, P.R. China
- Shanghai Key Laboratory of Clinical Geriatric Medicine , Shanghai, P.R. China
| | - Jing Xiao
- Department of Nephrology, Huadong Hospital Affiliated to Fudan University , Shanghai, P.R. China
- Shanghai Key Laboratory of Clinical Geriatric Medicine , Shanghai, P.R. China
| | - Zhibin Ye
- Department of Nephrology, Huadong Hospital Affiliated to Fudan University , Shanghai, P.R. China
- Shanghai Key Laboratory of Clinical Geriatric Medicine , Shanghai, P.R. China
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7
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Wang S, Wang Y, Wang J, Liu Z, Zhang R, Shi X, Han Y, Guo W, Bottillo I, Shao L. Six Exonic Variants in the SLC5A2 Gene Cause Exon Skipping in a Minigene Assay. Front Genet 2020; 11:585064. [PMID: 33250922 PMCID: PMC7674938 DOI: 10.3389/fgene.2020.585064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 10/20/2020] [Indexed: 01/16/2023] Open
Abstract
Background Familial renal glucosuria is a rare renal tubular disorder caused by SLC5A2 gene variants. Most of them are exonic variants and have been classified as missense variants. However, there is growing evidence that some of these variants can be detrimental by affecting the pre-mRNA splicing process. Therefore, we hypothesize that a certain proportion of SLC5A2 exonic variants can result in disease via interfering with the normal splicing process of the pre-mRNA. Methods We used bioinformatics programs to analyze 77 previously described presumed SLC5A2 missense variants and identified candidate variants that may alter the splicing of pre-mRNA through minigene assays. Results Our study indicated six of 7 candidate variants induced splicing alterations. Variants c.216C > A, c.294C > A, c.886G > C, c.932A > G and c.962A > G may disrupt splicing enhancer motifs and generate splicing silencer sequences resulting in the skipping of exon 3. Variants c.305C > T and c.1129G > A probably disturb splice sites leading to exon skipping. Conclusion To our knowledge, we report, for the first time, SLC5A2 exonic variants that produce alterations in pre-mRNA. Our research reinforces the importance of assessing the consequences for putative point variants at the mRNA level. Additionally, we propose that minigenes function analysis may be valuable to evaluate the impact of SLC5A2 exonic variants on pre-mRNA splicing without patients’ RNA samples.
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Affiliation(s)
- Sai Wang
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China.,Department of Dermatology, Peking University First Hospital, Beijing, China
| | - Yixiu Wang
- Department of Hepatic Surgery, Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jinchao Wang
- Yantai Branch of Wenden Osteopathic Hospital, Yantai, China
| | - Zhiying Liu
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Ruixiao Zhang
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Xiaomeng Shi
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Yue Han
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Wencong Guo
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Irene Bottillo
- Division of Medical Genetics, Department of Molecular Medicine, Sapienza University, San Camillo-Forlanini Hospital, Italy
| | - Leping Shao
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
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8
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Gyimesi G, Pujol-Giménez J, Kanai Y, Hediger MA. Sodium-coupled glucose transport, the SLC5 family, and therapeutically relevant inhibitors: from molecular discovery to clinical application. Pflugers Arch 2020; 472:1177-1206. [PMID: 32767111 PMCID: PMC7462921 DOI: 10.1007/s00424-020-02433-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/24/2020] [Accepted: 07/02/2020] [Indexed: 02/06/2023]
Abstract
Sodium glucose transporters (SGLTs) belong to the mammalian solute carrier family SLC5. This family includes 12 different members in human that mediate the transport of sugars, vitamins, amino acids, or smaller organic ions such as choline. The SLC5 family belongs to the sodium symporter family (SSS), which encompasses transporters from all kingdoms of life. It furthermore shares similarity to the structural fold of the APC (amino acid-polyamine-organocation) transporter family. Three decades after the first molecular identification of the intestinal Na+-glucose cotransporter SGLT1 by expression cloning, many new discoveries have evolved, from mechanistic analysis to molecular genetics, structural biology, drug discovery, and clinical applications. All of these advances have greatly influenced physiology and medicine. While SGLT1 is essential for fast absorption of glucose and galactose in the intestine, the expression of SGLT2 is largely confined to the early part of the kidney proximal tubules, where it reabsorbs the bulk part of filtered glucose. SGLT2 has been successfully exploited by the pharmaceutical industry to develop effective new drugs for the treatment of diabetic patients. These SGLT2 inhibitors, termed gliflozins, also exhibit favorable nephroprotective effects and likely also cardioprotective effects. In addition, given the recent finding that SGLT2 is also expressed in tumors of pancreas and prostate and in glioblastoma, this opens the door to potential new therapeutic strategies for cancer treatment by specifically targeting SGLT2. Likewise, further discoveries related to the functional association of other SGLTs of the SLC5 family to human pathologies will open the door to potential new therapeutic strategies. We furthermore hope that the herein summarized information about the physiological roles of SGLTs and the therapeutic benefits of the gliflozins will be useful for our readers to better understand the molecular basis of the beneficial effects of these inhibitors, also in the context of the tubuloglomerular feedback (TGF), and the renin-angiotensin system (RAS). The detailed mechanisms underlying the clinical benefits of SGLT2 inhibition by gliflozins still warrant further investigation that may serve as a basis for future drug development.
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Affiliation(s)
- Gergely Gyimesi
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, and Department of Biomedical Research, Inselspital, University of Bern, Kinderklinik, Office D845, Freiburgstrasse 15, CH-3010, Bern, Switzerland
| | - Jonai Pujol-Giménez
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, and Department of Biomedical Research, Inselspital, University of Bern, Kinderklinik, Office D845, Freiburgstrasse 15, CH-3010, Bern, Switzerland
| | - Yoshikatsu Kanai
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Matthias A Hediger
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, and Department of Biomedical Research, Inselspital, University of Bern, Kinderklinik, Office D845, Freiburgstrasse 15, CH-3010, Bern, Switzerland.
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9
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Yu L, Wu M, Hou P, Zhang H. SLC5A2 mutations, including two novel mutations, responsible for renal glucosuria in Chinese families. BMC Nephrol 2020; 21:69. [PMID: 32111189 PMCID: PMC7047355 DOI: 10.1186/s12882-020-01725-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 02/14/2020] [Indexed: 11/26/2022] Open
Abstract
Background Familial renal glucosuria (FRG) is characterized by persistent glucosuria without other impairments of tubular function in the presence of normal serum glucose. SGLT2, which is almost exclusively expressed in the kidney, accounts for most of the glucose reabsorption. Recently, some studies have confirmed that SLC5A2 mutations are responsible for the pathogenesis of familial renal glucosuria, but FRG cases are still rare. Furthermore, there are a few reports about splice-site mutations in previous studies, but the effect of these variants at the mRNA level has hardly been verified. Methods Ten patients were recruited in our renal division because of persistent glucosuria, and clinical data of the patients and their family members were recorded as much as possible. The entire coding region and adjacent intronic segments of SLC5A2 were sequenced in FRG patients and their relatives. Permanent growing lymphoblastoid cell lines from FRG patients were established to better preserve genetic information. Results A total of nine different mutations were identified: IVS1-16C > A, c.305C > T/p.(A102V), c.395G > A/p.(R132H), c.736C > T/p.(P246S), c.886(−10_-31)delGCAAGCGGGCAGCTGAACGCCC, c.1152_1163delGGTCATGCTGGC/p.(Val385_Ala388del), c.1222G > T/p.(D408Y), c.1496G > A/p.(R499H) and c.1540C > T/p.(P514S); two novel mutations in SLC5A2, c.1222G > T/p.(D408Y) and c.1496G > A/p.(R499H), were identified in the Chinese FRG pedigrees. Ten individuals with heterozygous or compound heterozygous variants had glucosuria in the range of 3.1 to 37.6 g/d. Conclusion We screened ten additional Chinese FRG pedigrees for mutations in the SLC5A2 gene and found nine mutations, including two novel mutations. Most variants were private, but IVS1-16C > A and c.886(−10_-31) del may be high frequency splice-site mutations that could be preferentially screened when variants cannot be found in the SLC5A2 exon. Furthermore, we successfully established a permanent growing lymphoblastoid cell line from patients with FRG, which could facilitate further studies of the SLC5A2 gene. The current study provides a valuable clue for further research on the molecular mechanism of SGLT2.
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Affiliation(s)
- Lei Yu
- Renal Division, Inner Mongolia People's Hospital, Hohhot, Inner Mongolia, 010017, People's Republic of China.
| | - Meng Wu
- Department of Nephrology, Longyan First Hospital Affiliated to Fujian Medical University, Longyan, Fujian, 364000, People's Republic of China
| | - Ping Hou
- Renal Division, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, People's Republic of China
| | - Hong Zhang
- Renal Division, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, People's Republic of China
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10
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Khitan ZJ, Glassock RJ. Foamy Urine: Is This a Sign of Kidney Disease? Clin J Am Soc Nephrol 2019; 14:1664-1666. [PMID: 31575619 PMCID: PMC6832055 DOI: 10.2215/cjn.06840619] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Zeid J Khitan
- Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia; and
| | - Richard J Glassock
- Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
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11
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van der Wijst J, Belge H, Bindels RJM, Devuyst O. Learning Physiology From Inherited Kidney Disorders. Physiol Rev 2019; 99:1575-1653. [PMID: 31215303 DOI: 10.1152/physrev.00008.2018] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The identification of genes causing inherited kidney diseases yielded crucial insights in the molecular basis of disease and improved our understanding of physiological processes that operate in the kidney. Monogenic kidney disorders are caused by mutations in genes coding for a large variety of proteins including receptors, channels and transporters, enzymes, transcription factors, and structural components, operating in specialized cell types that perform highly regulated homeostatic functions. Common variants in some of these genes are also associated with complex traits, as evidenced by genome-wide association studies in the general population. In this review, we discuss how the molecular genetics of inherited disorders affecting different tubular segments of the nephron improved our understanding of various transport processes and of their involvement in homeostasis, while providing novel therapeutic targets. These include inherited disorders causing a dysfunction of the proximal tubule (renal Fanconi syndrome), with emphasis on epithelial differentiation and receptor-mediated endocytosis, or affecting the reabsorption of glucose, the handling of uric acid, and the reabsorption of sodium, calcium, and magnesium along the kidney tubule.
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Affiliation(s)
- Jenny van der Wijst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - Hendrica Belge
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - Olivier Devuyst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
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12
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Cannizzaro M, Jarošová J, De Paepe B. Relevance of solute carrier family 5 transporter defects to inherited and acquired human disease. J Appl Genet 2019; 60:305-317. [PMID: 31286439 DOI: 10.1007/s13353-019-00502-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 06/21/2019] [Accepted: 06/30/2019] [Indexed: 01/12/2023]
Abstract
The solute carrier (SLC) group of membrane transport proteins is crucial for cells via their control of import and export of vital molecules across the cellular membrane. Defects in these transporters with narrow substrate specificities cause monogenic disorders, giving us essential clues of their precise roles in cellular functioning. The SLC5 family in particular has been linked to various human diseases, of mild and severe phenotype as well as high and low prevalence. In this review, we describe the effects on health of SLC5 dysfunction and dysregulation by summarizing findings in patients with transporter gene defects. Patients display a plethora of pathologies which include glucose/galactose malabsorption, familiar renal glycosuria, thyroid dyshormonogenesis, and distal hereditary motor neuronopathies. In addition, the therapeutic potential of intervening in transporter activities for treating common diseases such as diabetes and cancer is explored.
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Affiliation(s)
- Miryam Cannizzaro
- Department of Neurology & Neuromuscular Reference Center, Ghent University Hospital, Corneel Heymanslaan 10, 9000, Ghent, Belgium
| | - Jana Jarošová
- Department of Neurology & Neuromuscular Reference Center, Ghent University Hospital, Corneel Heymanslaan 10, 9000, Ghent, Belgium
| | - Boel De Paepe
- Department of Neurology & Neuromuscular Reference Center, Ghent University Hospital, Corneel Heymanslaan 10, 9000, Ghent, Belgium.
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13
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Li S, Yang Y, Huang L, Kong M, Yang Z. A novel compound heterozygous mutation in SLC5A2 contributes to familial renal glucosuria in a Chinese family, and a review of the relevant literature. Mol Med Rep 2019; 19:4364-4376. [PMID: 30942416 PMCID: PMC6472135 DOI: 10.3892/mmr.2019.10110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 02/21/2019] [Indexed: 12/17/2022] Open
Abstract
Familial renal glucosuria (FRG) is a rare condition that involves isolated glucosuria despite normal blood glucose levels. Mutations in the solute carrier family 5 member 2 (SLC5A2) gene, which encodes sodium-glucose cotransporter 2 (SGLT2), have been reported to be responsible for the disease. Genetic testing of the SLC5A2 gene was conducted in a Chinese family with FRG. A number of online tools were used to predict the potential effect of the identified mutations on SGLT2 function. Additionally, the SLC5A2 mutations previously reported in PubMed were summarized. A novel compound heterozygous mutation (c.514T>C, p.W172R; c.1540C>T, p.P514S) of the SLC5A2 gene in a Chinese child with FRG was identified. In total, 86 mutations of the SLC5A2 gene have been reported to be associated with FRG. The novel compound heterozygous mutation (c.514T>C, p.W172R; c.1540C>T, p.P514S) of the SLC5A2 gene may be responsible for the onset of FRG. The present study provides a starting point for further investigation of the molecular pathogenesis of the SLC5A2 gene mutation in patients with FRG.
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Affiliation(s)
- Shentang Li
- Department of Pediatrics, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China
| | - Yeyi Yang
- Department of Medicine, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China
| | - Lihua Huang
- Central Laboratory, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China
| | - Min Kong
- Department of Pediatrics, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China
| | - Zuocheng Yang
- Department of Pediatrics, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China
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14
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Gloyn AL, Drucker DJ. Precision medicine in the management of type 2 diabetes. Lancet Diabetes Endocrinol 2018; 6:891-900. [PMID: 29699867 DOI: 10.1016/s2213-8587(18)30052-4] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 02/02/2018] [Accepted: 02/02/2018] [Indexed: 12/15/2022]
Abstract
The study of type 2 diabetes has been driven by advances in human genetics, epigenetics, biomarkers, mechanistic studies, and large clinical trials, enabling new insights into disease susceptibility, pathophysiology, progression, and development of complications. Simultaneously, several new drug classes with different mechanisms of action have been introduced over the past two decades, accompanied by data about cardiovascular safety and non-glycaemic outcomes. In this Review, we critically examine the progress and integration of this new science into clinical practice, and review opportunities for enabling the use of precision medicine in the diagnosis and treatment of type 2 diabetes. We contrast the success in delivering personalised medicine for monogenic diabetes with the greater challenge of providing a precision medicine approach for type 2 diabetes, highlighting gaps, limitations, and areas requiring further study.
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Affiliation(s)
- Anna L Gloyn
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK; Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - Daniel J Drucker
- Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada.
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15
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Finucane FM. SGLT2 inhibitor-induced euglycaemic diabetic ketoacidosis may be due to abrupt, severe and transient impaired glucose sensing in susceptible individuals with a hitherto unrecognised beta cell SGLT variant. Med Hypotheses 2018; 114:11-12. [PMID: 29602453 DOI: 10.1016/j.mehy.2018.02.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 02/22/2018] [Indexed: 11/29/2022]
Abstract
Euglycaemic diabetic ketoacidosis (EDKA) is a rare complication of treatment with SGLT2 inhibitors in patients with type 2 diabetes. Uncertainty remains about its precise mechanistic basis, but the physiological derangement is acute and profound, yet reversible with cessation of the drug. It is reminiscent of other "non type 1" presentations with DKA such as ketosis prone diabetes, except that glucose levels are usually normal. Impaired beta cell glucose sensing that mimicked a state of hypoglycaemia could theoretically lead to abrupt and transient cessation of insulin secretion. GLUT2 mediates glucose sensing in beta cells. In other tissues such as enterocytes, GLUT2 mediated glucose transport is controlled by SGLT1. Although the affinity of SGLT1 for SGLT2 inhibitors is low, hypothetically a rare variant within the SGLT family with a hitherto unrecognised role in GLUT2 mediated glucose sensing might have an affinity for the SGLT2 inhibitor ligand and thus give rise to acute, severe but reversible euglycaemic DKA in susceptible patients.
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Affiliation(s)
- F M Finucane
- HRB Clinical Research Facility, NUI Galway, Ireland.
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16
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Urakami T, Yoda M, Yoshida K, Mine Y, Aoki M, Suzuki J. Renal glucosuria in schoolchildren: Clinical characteristics. Pediatr Int 2018; 60:35-40. [PMID: 29110414 DOI: 10.1111/ped.13456] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 07/04/2017] [Accepted: 08/22/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND We conducted an annual urine glucose screening program at schools, and diagnosed schoolchildren with diabetes at an early stage of the disease. We also identified some cases of renal glucosuria (RG), based on positive urine glucose with normal glucose tolerance. METHODS During 2000-2015, 3 309 631 schoolchildren participated in the screening program. The positive rate for glucosuria in the first test was approximately 0.1%, whereas on repeat urine test it was approximately 0.05%. In total 350 schoolchildren were positive for glucosuria on detailed examination. Oral glucose tolerance test (OGTT) was also used to evaluate glucose intolerance. RESULTS One hundred and two schoolchildren (29.7%) were diagnosed with diabetes, whereas RG was identified in 246 (70.3%) with normal glucose metabolism. In regard to the characteristics of RG, the percentage of boys was 50.3%, and the mean age at diagnosis was 11.2 ± 2.4 years. Twenty-eight children (11.4%) were overweight (body mass index standard deviation score [BMI-SDS] > +2.0 SD), whereas five (2.0%) were underweight (BMI-SDS < -2.0 SD). First-degree family history was suspected in 176 cases (71.5%). All RG subjects had normal glucose tolerance in the absence of insulin resistance and decreased insulin secretion (homeostasis model assessment for β-cell function, 78.8 ± 59.5%) on OGTT. CONCLUSIONS RG is not rare in Japanese schoolchildren with glucosuria. This disorder seems to have a strong genetic background, and to involve less growth retardation and weight loss than expected despite continuous excretion of glucose in urine.
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Affiliation(s)
- Tatsuhiko Urakami
- Department of Pediatrics, Nihon University School of Medicine, Tokyo, Japan
| | - Midori Yoda
- Department of Pediatrics, Nihon University School of Medicine, Tokyo, Japan
| | - Kei Yoshida
- Department of Pediatrics, Nihon University School of Medicine, Tokyo, Japan
| | - Yusuke Mine
- Department of Pediatrics, Nihon University School of Medicine, Tokyo, Japan
| | - Masako Aoki
- Department of Pediatrics, Nihon University School of Medicine, Tokyo, Japan
| | - Junichi Suzuki
- Department of Pediatrics, Nihon University School of Medicine, Tokyo, Japan
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17
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Wang X, Yu M, Wang T, Zhang H, Ping F, Zhang Q, Xu J, Feng K, Xiao X. Genetic analysis and literature review of Chinese patients with familial renal glucosuria: Identification of a novel SLC5A2 mutation. Clin Chim Acta 2017; 469:105-110. [DOI: 10.1016/j.cca.2017.03.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/12/2017] [Accepted: 03/28/2017] [Indexed: 11/26/2022]
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18
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Shepard BD, Pluznick JL. Saving the sweetness: renal glucose handling in health and disease. Am J Physiol Renal Physiol 2017; 313:F55-F61. [PMID: 28356283 DOI: 10.1152/ajprenal.00046.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 03/22/2017] [Accepted: 03/22/2017] [Indexed: 12/29/2022] Open
Abstract
Glucose homeostasis is highly controlled, and the function of the kidney plays an integral role in this process. The exquisite control of blood glucose relies, in part, on renal glucose filtration, renal glucose reabsorption, and renal gluconeogenesis. Particularly critical to maintaining glucose homeostasis is the renal reabsorption of glucose; with ~162 g of glucose filtered by the kidney per day, it is imperative that the kidney have the ability to efficiently reabsorb nearly 100% of this glucose back in the bloodstream. In this review, we focus on this central process, highlighting the renal transporters and regulators involved in both the physiology and pathophysiology of glucose reabsorption.
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Affiliation(s)
- Blythe D Shepard
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jennifer L Pluznick
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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19
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Hung CC, Lin HYH, Lee JJ, Lim LM, Chiu YW, Chiang HP, Hwang SJ, Chen HC. Glycosuria and Renal Outcomes in Patients with Nondiabetic Advanced Chronic Kidney Disease. Sci Rep 2016; 6:39372. [PMID: 28008953 PMCID: PMC5180243 DOI: 10.1038/srep39372] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 11/21/2016] [Indexed: 01/24/2023] Open
Abstract
Sodium glucose cotransporter 2 inhibitors have shown a potential for renoprotection beyond blood glucose lowering. Glycosuria in nondiabetic patients with chronic kidney disease (CKD) is sometimes noted. Whether glycosuria in CKD implies a channelopathy or proximal tubulopathy is not known. The consequence of glycosuria in CKD is also not studied. We performed a cross-sectional study for the association between glycosuria and urine electrolyte excretion in 208 nondiabetic patients. Fractional excretion (FE) of glucose >4% was 3.4%, 6.3% and 62.5% in CKD stage 3, 4 and 5, respectively. These patients with glycosuria had higher FE sodium, FE potassium, FE uric acid, UPCR, and urine NGAL-creatinine ratio. We conducted a longitudinal study for the consequence of glycosuria, defined by dipstick, in 769 nondiabetic patients with stage 4-5 CKD. Glycosuria was associated with a decreased risk for end-stage renal disease (adjusted hazard ratio: 0.77; CI = 0.62-0.97; p = 0.024) and for rapid renal function decline (adjusted odds ratio: 0.63; CI = 0.43-0.95; p = 0.032); but glycosuria was not associated with all-cause mortality or cardiovascular events. The results were consistent in the propensity-score matched cohort. Glycosuria is associated with increased fractional excretion of electrolytes and is related to favorable renal outcomes in nondiabetic patients with stage 5 CKD.
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Affiliation(s)
- Chi-Chih Hung
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hugo You-Hsien Lin
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jia-Jung Lee
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Lee Moay Lim
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Wen Chiu
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Faculty of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Heng-Pin Chiang
- Department of Healthcare Administration and Medical Informatics, Kaohsiung Medical University, Kaohsiung, Taiwan
- Division of Nephrology, Department of Internal Medicine, Jiannren Hospital, Kaohsiung, Taiwan
| | - Shang-Jyh Hwang
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Faculty of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hung-Chun Chen
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Faculty of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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20
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Zhao X, Cui L, Lang Y, Liu T, Lu J, Wang C, Tuffery-Giraud S, Bottillo I, Wang X, Shao L. A recurrent deletion in the SLC5A2 gene including the intron 7 branch site responsible for familial renal glucosuria. Sci Rep 2016; 6:33920. [PMID: 27666404 PMCID: PMC5036194 DOI: 10.1038/srep33920] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 09/06/2016] [Indexed: 12/31/2022] Open
Abstract
Familial renal glycosuria (FRG) is caused by mutations in the SLC5A2 gene, which codes for Na+-glucose co-transporters 2 (SGLT2). The aim of this study was to analyze and identify the mutations in 16 patients from 8 families with FRG. All coding regions, including intron-exon boundaries, were analyzed using PCR followed by direct sequence analysis. Six mutations in SLC5A2 gene were identified, including five missense mutations (c.393G > C, p.K131N; c.1003A > G, p.S335G; c.1343A > G, p.Q448R; c.1420G > C, p.A474P; c.1739G > A, p.G580D) and a 22-bp deletion in intron 7 (c.886(-10_-31)del) removing the putative branch point sequence. By the minigene studies using the pSPL3 plasmids, we confirmed that the deletion c.886(-10_-31)del acts as a splicing mutation. Furthermore, we found that this deletion causes exclusion of exon 8 in the SCL5A2 transcript in patients. The mutation c.886(-10_-31)del was present in 5 (62.5%) of 8 families, and accounts for about 37.5% of the total alleles (6/16). In conclusion, six mutations resulting in FRG were found, and the c.886(-10_-31)del may be the high frequency mutation that can be screened in FRG patients with uniallelic or negative SLC5A2 mutations.
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Affiliation(s)
- Xiangzhong Zhao
- Central Laboratory, The Affiliated Hospital of Qingdao University, 1677 Wutaishan Road, Qingdao 266555, China
| | - Li Cui
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
| | - Yanhua Lang
- Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
| | - Ting Liu
- Central Laboratory, The Affiliated Hospital of Qingdao University, 1677 Wutaishan Road, Qingdao 266555, China.,Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
| | - Jingru Lu
- Central Laboratory, The Affiliated Hospital of Qingdao University, 1677 Wutaishan Road, Qingdao 266555, China.,Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
| | - Cui Wang
- Central Laboratory, The Affiliated Hospital of Qingdao University, 1677 Wutaishan Road, Qingdao 266555, China.,Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
| | - Sylvie Tuffery-Giraud
- Laboratory of Genetics of Rare Diseases, EA7402, University of Montpellier, F-34000, France
| | - Irene Bottillo
- Division of Medical Genetics, Department of Molecular Medicine, Sapienza University, San Camillo-Forlanini Hospital, Circ. Gianicolense, 87, Padiglione Morgagni 00152, Rome, Italy
| | - Xinsheng Wang
- Urology, Affiliated Hospital, Qingdao University, Qingdao 266003, China
| | - Leping Shao
- Central Laboratory, The Affiliated Hospital of Qingdao University, 1677 Wutaishan Road, Qingdao 266555, China.,Department of Nephrology, the Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
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Yu L, Hou P, Liu GP, Zhang H. Novel SLC5A2 mutation contributes to familial renal glucosuria: Abnormal expression in renal tissues. Exp Ther Med 2016; 12:649-652. [PMID: 27446256 PMCID: PMC4950299 DOI: 10.3892/etm.2016.3388] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 04/27/2016] [Indexed: 12/18/2022] Open
Abstract
Familial renal glucosuria (FRG) is characterized by persistent glucosuria in the presence of normal serum glucose concentrations, while other impairments of tubular function are absent. Mutations in the sodium-glucose co-transporter 2 (SLC5A2) gene have been found to be responsible for FRG. However, direct evidence for the presence of SLC5A2 mutant in renal tissues is very rare. In previous studies, a non-sense mutation (c.1320 G>A:p.W440X) that would cause premature termination of the protein was found. However, the effects in the renal tissues were not reported. In the current study, a patient with FRG and a urinary glucose excretion rate of 8.3 g/day is described, for whom a novel missense mutation (c.1319G>A:p.W440X) was revealed by sequencing. Furthermore, in the immunofluorescence examination of a renal biopsy specimen, SLC5A2 was detected in the apical side of the proximal convoluted tubule, discontinuously decreased in comparison with that in normal and disease controls. The results imply that both wild-type SLC5A2 and mutant SLC5A2 with abnormal distribution were expressed in the renal tissues, and that the reduction of SLC5A2 expression and function were due to the c.1319G>A:p.W440X mutation. The current study provides valuable clues regarding the SLC5A2 molecule from genotype to phenotype in families affected by FRG.
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Affiliation(s)
- Lei Yu
- Renal Division, Inner Mongolia People's Hospital, Hohhot, Inner Mongolia 010017, P.R. China
| | - Ping Hou
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Key Laboratory of Renal Disease, Ministry of Health of China, Beijing 100034, P.R. China
| | - Guo-Ping Liu
- Renal Division, Inner Mongolia People's Hospital, Hohhot, Inner Mongolia 010017, P.R. China
| | - Hong Zhang
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Key Laboratory of Renal Disease, Ministry of Health of China, Beijing 100034, P.R. China
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Ottosson-Laakso E, Tuomi T, Forsén B, Gullström M, Groop PH, Groop L, Vikman P. Influence of Familial Renal Glycosuria Due to Mutations in the SLC5A2 Gene on Changes in Glucose Tolerance over Time. PLoS One 2016; 11:e0146114. [PMID: 26735923 PMCID: PMC4703216 DOI: 10.1371/journal.pone.0146114] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/14/2015] [Indexed: 12/30/2022] Open
Abstract
Familial renal glycosuria is an inherited disorder resulting in glucose excretion in the urine despite normal blood glucose concentrations. It is most commonly due to mutations in the SLC5A2 gene coding for the glucose transporter SGLT2 in the proximal tubule. Several drugs have been introduced as means to lower glucose in patients with type 2 diabetes targeting SGLT2 resulting in renal glycosuria, but no studies have addressed the potential effects of decreased renal glucose reabsorption and chronic glycosuria on the prevention of glucose intolerance. Here we present data on a large pedigree with renal glycosuria due to two mutations (c.300-303+2del and p.A343V) in the SLC5A2 gene. The mutations, which in vitro affected glucose transport in a cell line model, and the ensuing glycosuria were not associated with better glycemic control during a follow-up period of more than 10 years. One individual, who was compound heterozygous for mutations in the SLC5A2 gene suffered from severe urogenital candida infections and postprandial hypoglycemia. In conclusion, in this family with familial glycosuria we did not find any evidence that chronic loss of glucose in the urine would protect from deterioration of the glucose tolerance over time.
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Affiliation(s)
- Emilia Ottosson-Laakso
- Diabetes and Endocrinology, Department of Clinical Sciences, Lund University, Malmö, Sweden
- * E-mail:
| | - Tiinamaija Tuomi
- Folkhälsan Institute of Genetics, Folkhälsan Research Centre, Biomedicum, Helsinki, Finland
- Research Program Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland
- Finnish Institute of Molecular Medicine, University of Helsinki, Helsinki, Finland
| | | | | | - Per-Henrik Groop
- Folkhälsan Institute of Genetics, Folkhälsan Research Centre, Biomedicum, Helsinki, Finland
- Research Program Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland
- Abdominal Center Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Leif Groop
- Diabetes and Endocrinology, Department of Clinical Sciences, Lund University, Malmö, Sweden
- Finnish Institute of Molecular Medicine, University of Helsinki, Helsinki, Finland
| | - Petter Vikman
- Diabetes and Endocrinology, Department of Clinical Sciences, Lund University, Malmö, Sweden
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Gattineni J, Baum M. Developmental changes in renal tubular transport-an overview. Pediatr Nephrol 2015; 30:2085-98. [PMID: 24253590 PMCID: PMC4028442 DOI: 10.1007/s00467-013-2666-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 10/01/2013] [Accepted: 10/11/2013] [Indexed: 10/26/2022]
Abstract
The adult kidney maintains a constant volume and composition of extracellular fluid despite changes in water and salt intake. The neonate is born with a kidney that has a small fraction of the glomerular filtration rate of the adult and immature tubules that function at a lower capacity than that of the mature animal. Nonetheless, the neonate is also able to maintain a constant extracellular fluid volume and composition. Postnatal renal tubular development was once thought to be due to an increase in the transporter abundance to meet the developmental increase in glomerular filtration rate. However, postnatal renal development of each nephron segment is quite complex. There are isoform changes of several transporters as well as developmental changes in signal transduction that affect the capacity of renal tubules to reabsorb solutes and water. This review will discuss neonatal tubular function with an emphasis on the differences that have been found between the neonate and adult. We will also discuss some of the factors that are responsible for the maturational changes in tubular transport that occur during postnatal renal development.
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Affiliation(s)
- Jyothsna Gattineni
- Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9061, USA
| | - Michel Baum
- Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9061, USA.
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Aires I, Santos AR, Pratas J, Nolasco F, Calado J. Hypouricaemia and hyperuricosuria in familial renal glucosuria. Clin Kidney J 2015; 6:523-5. [PMID: 26064518 PMCID: PMC4438413 DOI: 10.1093/ckj/sft100] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Familial renal glucosuria is a rare co-dominantly inherited benign phenotype characterized by the presence of glucose in the urine. It is caused by mutations in the SLC5A2 gene that encodes SGLT2, the Na+-glucose cotransporter responsible for the reabsorption of the bulk of glucose in the proximal tubule. We report a case of FRG displaying both severe glucosuria and renal hypouricaemia. We hypothesize that glucosuria can disrupt urate reabsorption in the proximal tubule, directly causing hyperuricosuria.
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Affiliation(s)
- Inês Aires
- Department of Medicine and Nephrology, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa-Hospital de Curry Cabral, Lisboa, Portugal
- Department of Genetics, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Ana Rita Santos
- Department of Medicine and Nephrology, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa-Hospital de Curry Cabral, Lisboa, Portugal
| | - Jorge Pratas
- Department of Nephrology, Hospitais Universitários de Coimbra, Coimbra, Portugal
| | - Fernando Nolasco
- Department of Medicine and Nephrology, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa-Hospital de Curry Cabral, Lisboa, Portugal
| | - Joaquim Calado
- Department of Medicine and Nephrology, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa-Hospital de Curry Cabral, Lisboa, Portugal
- Department of Genetics, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisboa, Portugal
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Bonner C, Kerr-Conte J, Gmyr V, Queniat G, Moerman E, Thévenet J, Beaucamps C, Delalleau N, Popescu I, Malaisse WJ, Sener A, Deprez B, Abderrahmani A, Staels B, Pattou F. Inhibition of the glucose transporter SGLT2 with dapagliflozin in pancreatic alpha cells triggers glucagon secretion. Nat Med 2015; 21:512-7. [PMID: 25894829 DOI: 10.1038/nm.3828] [Citation(s) in RCA: 465] [Impact Index Per Article: 51.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 02/19/2015] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes (T2D) is characterized by chronic hyperglycemia resulting from a deficiency in insulin signaling, because of insulin resistance and/or defects in insulin secretion; it is also associated with increases in glucagon and endogenous glucose production (EGP). Gliflozins, including dapagliflozin, are a new class of approved oral antidiabetic agents that specifically inhibit sodium-glucose co-transporter 2 (SGLT2) function in the kidney, thus preventing renal glucose reabsorption and increasing glycosuria in diabetic individuals while reducing hyperglycemia. However, gliflozin treatment in subjects with T2D increases both plasma glucagon and EGP by unknown mechanisms. In spite of the rise in EGP, T2D patients treated with gliflozin have lower blood glucose levels than those receiving placebo, possibly because of increased glycosuria; however, the resulting increase in plasma glucagon levels represents a possible concerning side effect, especially in a patient population already affected by hyperglucagonemia. Here we demonstrate that SGLT2 is expressed in glucagon-secreting alpha cells of the pancreatic islets. We further found that expression of SLC5A2 (which encodes SGLT2) was lower and glucagon (GCG) gene expression was higher in islets from T2D individuals and in normal islets exposed to chronic hyperglycemia than in islets from non-diabetics. Moreover, hepatocyte nuclear factor 4-α (HNF4A) is specifically expressed in human alpha cells, in which it controls SLC5A2 expression, and its expression is downregulated by hyperglycemia. In addition, inhibition of either SLC5A2 via siRNA-induced gene silencing or SGLT2 via dapagliflozin treatment in human islets triggered glucagon secretion through KATP channel activation. Finally, we found that dapagliflozin treatment further promotes glucagon secretion and hepatic gluconeogenesis in healthy mice, thereby limiting the decrease of plasma glucose induced by fasting. Collectively, these results identify a heretofore unknown role of SGLT2 and designate dapagliflozin an alpha cell secretagogue.
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Affiliation(s)
- Caroline Bonner
- 1] European Genomic Institute for Diabetes, Lille, France. [2] INSERM UMR 1190, Lille, France. [3] Centre Hospitalier Régional Universitaire, Lille, France
| | - Julie Kerr-Conte
- 1] European Genomic Institute for Diabetes, Lille, France. [2] INSERM UMR 1190, Lille, France. [3] Centre Hospitalier Régional Universitaire, Lille, France. [4] Université de Lille, Lille, France
| | - Valéry Gmyr
- 1] European Genomic Institute for Diabetes, Lille, France. [2] INSERM UMR 1190, Lille, France. [3] Université de Lille, Lille, France
| | - Gurvan Queniat
- 1] European Genomic Institute for Diabetes, Lille, France. [2] INSERM UMR 1190, Lille, France. [3] Université de Lille, Lille, France
| | - Ericka Moerman
- 1] European Genomic Institute for Diabetes, Lille, France. [2] INSERM UMR 1190, Lille, France. [3] Université de Lille, Lille, France
| | - Julien Thévenet
- 1] European Genomic Institute for Diabetes, Lille, France. [2] INSERM UMR 1190, Lille, France. [3] Université de Lille, Lille, France
| | - Cédric Beaucamps
- 1] European Genomic Institute for Diabetes, Lille, France. [2] INSERM UMR 1190, Lille, France. [3] Centre Hospitalier Régional Universitaire, Lille, France
| | - Nathalie Delalleau
- 1] European Genomic Institute for Diabetes, Lille, France. [2] INSERM UMR 1190, Lille, France. [3] Université de Lille, Lille, France
| | - Iuliana Popescu
- Laboratory of Experimental Hormonology, Medical School, Université Libre de Bruxelles, Brussels, Belgium
| | - Willy J Malaisse
- Laboratory of Experimental Hormonology, Medical School, Université Libre de Bruxelles, Brussels, Belgium
| | - Abdullah Sener
- Laboratory of Experimental Hormonology, Medical School, Université Libre de Bruxelles, Brussels, Belgium
| | - Benoit Deprez
- 1] Université de Lille, Lille, France. [2] INSERM UMR 1177, Lille, France. [3] Institut Pasteur de Lille, Lille, France
| | - Amar Abderrahmani
- 1] European Genomic Institute for Diabetes, Lille, France. [2] Université de Lille, Lille, France. [3] CNRS UMR 8199, Lille, France
| | - Bart Staels
- 1] European Genomic Institute for Diabetes, Lille, France. [2] Université de Lille, Lille, France. [3] Institut Pasteur de Lille, Lille, France. [4] INSERM UMR 1011, Lille, France
| | - François Pattou
- 1] European Genomic Institute for Diabetes, Lille, France. [2] INSERM UMR 1190, Lille, France. [3] Centre Hospitalier Régional Universitaire, Lille, France. [4] Université de Lille, Lille, France
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Prié D. Familial renal glycosuria and modifications of glucose renal excretion. DIABETES & METABOLISM 2014; 40:S12-6. [DOI: 10.1016/s1262-3636(14)72690-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Yu L, Hou P, Lv JC, Liu GP, Zhang H. Novel SLC5A2 variants contribute to renal glucosuria in Chinese families: abnormal expression and dysfunction of variant SLC5A2. Hum Mutat 2014; 36:79-86. [PMID: 25339128 DOI: 10.1002/humu.22714] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 10/16/2014] [Indexed: 11/07/2022]
Abstract
Familial renal glucosuria (FRG) is characterized by persistent glucosuria despite normal serum glucose and the absence of overt tubular dysfunction. Variants in solute carrier family 5 (sodium-glucose cotransporter), member 2 (SLC5A2) have been reported in FRG patients. However, the functional and expression-related consequences of such variants have been scarcely investigated. In the current study, we studied five FRG families and identified six missense mutations, including four novel variants (c.1051T>C/.(C351R), c.1400T>C/p.(V467A), c.1420G>C/p.(A474P), c.1691G>A/p.(R564Q); RNA not analyzed) and two variants that had been previously reported (c.294C>A/p.(F98L), c.736C>T/p.(P246S); RNA not analyzed). The probands were either heterozygous or compound heterozygous for SLC5A2 variants and had glucosuria of 5.9%-19.6 g/day. Human 293 cells were transfected with plasmid constructs to study the expression and function of SLC5A2 variants in vitro. Western blotting revealed that the expression levels of SLC5A2-351R-GFP, SLC5A2-467A-GFP, SLC5A2-474P-GFP, and SLC5A2-564Q-GFP were significantly decreased compared with wild-type SLC5A2-GFP (37%-55%). Confocal microscopy revealed that three variants (c.1400T>C, c.1420G>C, c.1691G>A) resulted in a loss of the punctate membrane pattern typical of wild-type SLC5A2. All variants had a significantly lower transport capacity in than the wild-type control. The current study provides a starting point to further investigate the molecular mechanism of SLC5A2 in FRG families and provides functional clues for antidiabetes drugs.
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Affiliation(s)
- Lei Yu
- Renal Division, Inner Mongolia People's Hospital, Hohhot, People's Republic of China
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Yamane M, Kawashima K, Yamaguchi K, Nagao S, Sato M, Suzuki M, Honda K, Hagita H, Kuhlmann O, Poirier A, Fowler S, Funk C, Simon S, Aso Y, Ikeda S, Ishigai M. In vitroprofiling of the metabolism and drug–drug interaction of tofogliflozin, a potent and highly specific sodium-glucose co-transporter 2 inhibitor, using human liver microsomes, human hepatocytes, and recombinant human CYP. Xenobiotica 2014; 45:230-8. [DOI: 10.3109/00498254.2014.976296] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Sodium-glucose transporter-2 (SGLT2; SLC5A2) enhances cellular uptake of aminoglycosides. PLoS One 2014; 9:e108941. [PMID: 25268124 PMCID: PMC4182564 DOI: 10.1371/journal.pone.0108941] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 08/26/2014] [Indexed: 12/20/2022] Open
Abstract
Aminoglycoside antibiotics, like gentamicin, continue to be clinically essential worldwide to treat life-threatening bacterial infections. Yet, the ototoxic and nephrotoxic side-effects of these drugs remain serious complications. A major site of gentamicin uptake and toxicity resides within kidney proximal tubules that also heavily express electrogenic sodium-glucose transporter-2 (SGLT2; SLC5A2) in vivo. We hypothesized that SGLT2 traffics gentamicin, and promotes cellular toxicity. We confirmed in vitro expression of SGLT2 in proximal tubule-derived KPT2 cells, and absence in distal tubule-derived KDT3 cells. D-glucose competitively decreased the uptake of 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG), a fluorescent analog of glucose, and fluorescently-tagged gentamicin (GTTR) by KPT2 cells. Phlorizin, an SGLT2 antagonist, strongly inhibited uptake of 2-NBDG and GTTR by KPT2 cells in a dose- and time-dependent manner. GTTR uptake was elevated in KDT3 cells transfected with SGLT2 (compared to controls); and this enhanced uptake was attenuated by phlorizin. Knock-down of SGLT2 expression by siRNA reduced gentamicin-induced cytotoxicity. In vivo, SGLT2 was robustly expressed in kidney proximal tubule cells of heterozygous, but not null, mice. Phlorizin decreased GTTR uptake by kidney proximal tubule cells in Sglt2+/− mice, but not in Sglt2−/− mice. However, serum GTTR levels were elevated in Sglt2−/− mice compared to Sglt2+/− mice, and in phlorizin-treated Sglt2+/− mice compared to vehicle-treated Sglt2+/− mice. Loss of SGLT2 function by antagonism or by gene deletion did not affect gentamicin cochlear loading or auditory function. Phlorizin did not protect wild-type mice from kanamycin-induced ototoxicity. We conclude that SGLT2 can traffic gentamicin and contribute to gentamicin-induced cytotoxicity.
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Guo C, Hu M, DeOrazio RJ, Usyatinsky A, Fitzpatrick K, Zhang Z, Maeng JH, Kitchen DB, Tom S, Luche M, Khmelnitsky Y, Mhyre AJ, Guzzo PR, Liu S. The design and synthesis of novel SGLT2 inhibitors: C-glycosides with benzyltriazolopyridinone and phenylhydantoin as the aglycone moieties. Bioorg Med Chem 2014; 22:3414-22. [DOI: 10.1016/j.bmc.2014.04.036] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 04/11/2014] [Accepted: 04/20/2014] [Indexed: 11/29/2022]
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Kaku K, Watada H, Iwamoto Y, Utsunomiya K, Terauchi Y, Tobe K, Tanizawa Y, Araki E, Ueda M, Suganami H, Watanabe D. Efficacy and safety of monotherapy with the novel sodium/glucose cotransporter-2 inhibitor tofogliflozin in Japanese patients with type 2 diabetes mellitus: a combined Phase 2 and 3 randomized, placebo-controlled, double-blind, parallel-group comparative study. Cardiovasc Diabetol 2014; 13:65. [PMID: 24678906 PMCID: PMC4021346 DOI: 10.1186/1475-2840-13-65] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 03/09/2014] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND In recent years, several oral antidiabetic drugs with new mechanisms of action have become available, expanding the number of treatment options. Sodium/glucose cotransporter-2 (SGLT2) inhibitors are a new class of oral antidiabetic drugs with an insulin-independent mechanism promoting urinary glucose excretion. We report the results of a combined Phase 2 and 3 clinical study (Japic CTI-101349) of the SGLT2 inhibitor tofogliflozin (CSG452, RG7201) in Japanese patients with type 2 diabetes mellitus. METHODS The efficacy and safety of tofogliflozin were assessed in this multicenter, placebo-controlled, randomized, double-blind parallel-group study involving 230 patients with type 2 diabetes mellitus with inadequate glycemic control on diet/exercise therapy. Between 30 October 2010 and 28 February 2012, patients at 33 centers were randomized to either placebo (n = 56) or tofogliflozin (10, 20, or 40 mg; n = 58 each) orally, once daily for 24 weeks. The primary efficacy endpoint was the change from baseline in HbA1c at week 24. RESULTS Overall, 229 patients were included in the full analysis set (placebo: n = 56; tofogliflozin 10 mg: n = 57; tofogliflozin 20 and 40 mg: n = 58 each). The least squares (LS) mean change (95% confidence interval) from baseline in HbA1c at week 24 was -0.028% (-0.192 to 0.137) in the placebo group, compared with -0.797% (-0.960 to -0.634) in the tofogliflozin 10 mg group, -1.017% (-1.178 to -0.856) in the tofogliflozin 20 mg group, and -0.870% (-1.031 to -0.709) in the tofogliflozin 40 mg group (p < 0.0001 for the LS mean differences in all tofogliflozin groups vs placebo). There were also prominent decreases in fasting blood glucose, 2-h postprandial glucose, and body weight in all tofogliflozin groups compared with the placebo group. The main adverse events were hyperketonemia, ketonuria, and pollakiuria. The incidence of hypoglycemia was low. Furthermore, most adverse events were classified as mild or moderate in severity. CONCLUSIONS Tofogliflozin 10, 20, or 40 mg administered once daily as monotherapy significantly decreased HbA1c and body weight, and was generally well tolerated in Japanese patients with type 2 diabetes mellitus. Phase 3 studies were recently completed and support the findings of this combined Phase 2 and 3 study. TRIAL REGISTRATION This study was registered in the JAPIC clinical trials registry (ID: Japic CTI-101349).
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Affiliation(s)
- Kohei Kaku
- Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan.
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Klootwijk ED, Reichold M, Helip-Wooley A, Tolaymat A, Broeker C, Robinette SL, Reinders J, Peindl D, Renner K, Eberhart K, Assmann N, Oefner PJ, Dettmer K, Sterner C, Schroeder J, Zorger N, Witzgall R, Reinhold SW, Stanescu HC, Bockenhauer D, Jaureguiberry G, Courtneidge H, Hall AM, Wijeyesekera AD, Holmes E, Nicholson JK, O'Brien K, Bernardini I, Krasnewich DM, Arcos-Burgos M, Izumi Y, Nonoguchi H, Jia Y, Reddy JK, Ilyas M, Unwin RJ, Gahl WA, Warth R, Kleta R. Mistargeting of peroxisomal EHHADH and inherited renal Fanconi's syndrome. N Engl J Med 2014; 370:129-38. [PMID: 24401050 DOI: 10.1056/nejmoa1307581] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND In renal Fanconi's syndrome, dysfunction in proximal tubular cells leads to renal losses of water, electrolytes, and low-molecular-weight nutrients. For most types of isolated Fanconi's syndrome, the genetic cause and underlying defect remain unknown. METHODS We clinically and genetically characterized members of a five-generation black family with isolated autosomal dominant Fanconi's syndrome. We performed genomewide linkage analysis, gene sequencing, biochemical and cell-biologic investigations of renal proximal tubular cells, studies in knockout mice, and functional evaluations of mitochondria. Urine was studied with the use of proton nuclear magnetic resonance ((1)H-NMR) spectroscopy. RESULTS We linked the phenotype of this family's Fanconi's syndrome to a single locus on chromosome 3q27, where a heterozygous missense mutation in EHHADH segregated with the disease. The p.E3K mutation created a new mitochondrial targeting motif in the N-terminal portion of EHHADH, an enzyme that is involved in peroxisomal oxidation of fatty acids and is expressed in the proximal tubule. Immunocytofluorescence studies showed mistargeting of the mutant EHHADH to mitochondria. Studies of proximal tubular cells revealed impaired mitochondrial oxidative phosphorylation and defects in the transport of fluids and a glucose analogue across the epithelium. (1)H-NMR spectroscopy showed elevated levels of mitochondrial metabolites in urine from affected family members. Ehhadh knockout mice showed no abnormalities in renal tubular cells, a finding that indicates a dominant negative nature of the mutation rather than haploinsufficiency. CONCLUSIONS Mistargeting of peroxisomal EHHADH disrupts mitochondrial metabolism and leads to renal Fanconi's syndrome; this indicates a central role of mitochondria in proximal tubular function. The dominant negative effect of the mistargeted protein adds to the spectrum of monogenic mechanisms of Fanconi's syndrome. (Funded by the European Commission Seventh Framework Programme and others.).
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Affiliation(s)
- Enriko D Klootwijk
- From the Centre for Nephrology (E.D.K., H.C.S., D.B., G.J., H.C., A.M.H., R.J.U., R.K.) and Institute of Child Health (D.B., R.K.), University College London, and Biomolecular Medicine, Imperial College London (S.L.R., A.D.W., E.H., J.K.N.) - both in London; the Departments of Medical Cell Biology (M.R., C.B., D.P., C.S., R. Warth), Internal Medicine III (K.R.), Internal Medicine II (S.W.R.), and Molecular and Cellular Anatomy (R. Witzgall) and the Institutes of Functional Genomics (J.R., K.E., N.A., P.J.O., K.D.) and Pathology (J.S.), University of Regensburg, and the Department of Radiology, Barmherzige Brueder Hospital (N.Z.) - all in Regensburg, Germany; the National Human Genome Research Institute (A.H.-W., S.L.R., H.C.S., K.O., I.B., D.M.K., W.A.G., R.K.) and National Heart, Lung, and Blood Institute (Y.I.), National Institutes of Health, Bethesda, MD; the Division of Pediatric Nephrology, University of Florida, Jacksonville (A.T., M.I.); the Genome Biology Department, Australian National University, Canberra, ACT, Australia (M.A.-B.); Kitasato University Medical Center, Saitama, Japan (H.N.); and the Department of Pathology, Northwestern University, Chicago (Y.J., J.K.R.)
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Abstract
Diabetes mellitus contributes greatly to morbidity, mortality, and overall health care costs. In major part, these outcomes derive from the high incidence of progressive kidney dysfunction in patients with diabetes making diabetic nephropathy a leading cause of end-stage renal disease. A better understanding of the molecular mechanism involved and of the early dysfunctions observed in the diabetic kidney may permit the development of new strategies to prevent diabetic nephropathy. Here we review the pathophysiological changes that occur in the kidney in response to hyperglycemia, including the cellular responses to high glucose and the responses in vascular, glomerular, podocyte, and tubular function. The molecular basis, characteristics, and consequences of the unique growth phenotypes observed in the diabetic kidney, including glomerular structures and tubular segments, are outlined. We delineate mechanisms of early diabetic glomerular hyperfiltration including primary vascular events as well as the primary role of tubular growth, hyperreabsorption, and tubuloglomerular communication as part of a "tubulocentric" concept of early diabetic kidney function. The latter also explains the "salt paradox" of the early diabetic kidney, that is, a unique and inverse relationship between glomerular filtration rate and dietary salt intake. The mechanisms and consequences of the intrarenal activation of the renin-angiotensin system and of diabetes-induced tubular glycogen accumulation are discussed. Moreover, we aim to link the changes that occur early in the diabetic kidney including the growth phenotype, oxidative stress, hypoxia, and formation of advanced glycation end products to mechanisms involved in progressive kidney disease.
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Affiliation(s)
- Volker Vallon
- Department of Medicine, University of California San Diego & VA San Diego Healthcare System, San Diego, California, USA.
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Cherney DZI, Perkins BA, Soleymanlou N, Maione M, Lai V, Lee A, Fagan NM, Woerle HJ, Johansen OE, Broedl UC, von Eynatten M. Renal hemodynamic effect of sodium-glucose cotransporter 2 inhibition in patients with type 1 diabetes mellitus. Circulation 2013; 129:587-97. [PMID: 24334175 DOI: 10.1161/circulationaha.113.005081] [Citation(s) in RCA: 914] [Impact Index Per Article: 83.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND The primary objective of this mechanistic open-label, stratified clinical trial was to determine the effect of 8 weeks' sodium glucose cotransporter 2 inhibition with empagliflozin 25 mg QD on renal hyperfiltration in subjects with type 1 diabetes mellitus (T1D). METHODS AND RESULTS Inulin (glomerular filtration rate; GFR) and paraaminohippurate (effective renal plasma flow) clearances were measured in individuals stratified based on having hyperfiltration (T1D-H, GFR ≥ 135 mL/min/1.73m(2), n=27) or normal GFR (T1D-N, GFR 90-134 mL/min/1.73m(2), n=13) at baseline. Renal function and circulating levels of renin-angiotensin-aldosterone system mediators and NO were measured under clamped euglycemic (4-6 mmol/L) and hyperglycemic (9-11 mmol/L) conditions at baseline and end of treatment. During clamped euglycemia, hyperfiltration was attenuated by -33 mL/min/1.73m(2) with empagliflozin in T1D-H, (GFR 172±23-139±25 mL/min/1.73 m(2), P<0.01). This effect was accompanied by declines in plasma NO and effective renal plasma flow and an increase in renal vascular resistance (all P<0.01). Similar significant effects on GFR and renal function parameters were observed during clamped hyperglycemia. In T1D-N, GFR, other renal function parameters, and plasma NO were not altered by empagliflozin. Empagliflozin reduced hemoglobin A1c significantly in both groups, despite lower insulin doses in each group (P≤0.04). CONCLUSIONS In conclusion, short-term treatment with the sodium glucose cotransporter 2 inhibitor empagliflozin attenuated renal hyperfiltration in subjects with T1D, likely by affecting tubular-glomerular feedback mechanisms. CLINICAL TRIAL REGISTRATION URL http://www.clinicaltrials.gov. Unique identifier: NCT01392560.
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Affiliation(s)
- David Z I Cherney
- Department of Medicine, Division of Nephrology (D.Z.I.C., M.M., V.L., A.L.) and the Department of Medicine, Division of Endocrinology (B.A.P.), Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada; Boehringer Ingelheim Canada Ltd./Ltée, Burlington, Ontario, Canada (N.S.); Boehringer Ingelheim Pharmaceuticals Inc, Ridgefield, CT (N.M.F., M.v.E.); and Boehringer Ingelheim Pharma GmbH & Co.KG, Ingelheim, Germany (H.J.W., O.E.J., U.C.B.)
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Vallon V, Gerasimova M, Rose MA, Masuda T, Satriano J, Mayoux E, Koepsell H, Thomson SC, Rieg T. SGLT2 inhibitor empagliflozin reduces renal growth and albuminuria in proportion to hyperglycemia and prevents glomerular hyperfiltration in diabetic Akita mice. Am J Physiol Renal Physiol 2013; 306:F194-204. [PMID: 24226524 DOI: 10.1152/ajprenal.00520.2013] [Citation(s) in RCA: 348] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Our previous work has shown that gene knockout of the sodium-glucose cotransporter SGLT2 modestly lowered blood glucose in streptozotocin-diabetic mice (BG; from 470 to 300 mg/dl) and prevented glomerular hyperfiltration but did not attenuate albuminuria or renal growth and inflammation. Here we determined effects of the SGLT2 inhibitor empagliflozin (300 mg/kg of diet for 15 wk; corresponding to 60-80 mg·kg(-1)·day(-1)) in type 1 diabetic Akita mice that, opposite to streptozotocin-diabetes, upregulate renal SGLT2 expression. Akita diabetes, empagliflozin, and Akita + empagliflozin similarly increased renal membrane SGLT2 expression (by 38-56%) and reduced the expression of SGLT1 (by 33-37%) vs. vehicle-treated wild-type controls (WT). The diabetes-induced changes in SGLT2/SGLT1 protein expression are expected to enhance the BG-lowering potential of SGLT2 inhibition, and empagliflozin strongly lowered BG in Akita (means of 187-237 vs. 517-535 mg/dl in vehicle group; 100-140 mg/dl in WT). Empagliflozin modestly reduced GFR in WT (250 vs. 306 μl/min) and completely prevented the diabetes-induced increase in glomerular filtration rate (GFR) (255 vs. 397 μl/min). Empagliflozin attenuated increases in kidney weight and urinary albumin/creatinine ratio in Akita in proportion to hyperglycemia. Empagliflozin did not increase urinary glucose/creatinine ratios in Akita, indicating the reduction in filtered glucose balanced the inhibition of glucose reabsorption. Empagliflozin attenuated/prevented the increase in systolic blood pressure, glomerular size, and molecular markers of kidney growth, inflammation, and gluconeogenesis in Akita. We propose that SGLT2 inhibition can lower GFR independent of reducing BG (consistent with the tubular hypothesis of diabetic glomerular hyperfiltration), while attenuation of albuminuria, kidney growth, and inflammation in the early diabetic kidney may mostly be secondary to lower BG.
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Affiliation(s)
- Volker Vallon
- Div. of Nephrology and Hypertension, Depts. of Medicine and Pharmacology, Univ. of California San Diego and Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Dr. (9151 San Diego, CA 92161.
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Lee YW. Clinical and genetic analysis in a patient with primary renal glucosuria: Identification of a novel mutation in the SLC5A2 gene. Exp Ther Med 2013; 6:1532-1534. [PMID: 24255686 PMCID: PMC3829744 DOI: 10.3892/etm.2013.1326] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 09/30/2013] [Indexed: 11/26/2022] Open
Abstract
Primary renal glucosuria (PRG; OMIM #233100) is characterized by persistent glucosuria due to a reduction in the renal tubular reabsorption of glucose in the presence of a normal concentration of serum glucose and the absence of any other impairment of tubular function. The SLC5A2 gene is the causative gene, which codes for the low-affinity sodium/glucose co-transporter SGLT2. In the present study, the case of a patient with PRG associated with a novel mutation of the SLC5A2 gene is reported. The patient visited hospital for the evaluation of glucosuria in the absence of hyperglycemia, a condition that had been present for >20 years. The patient showed a fasting blood sugar level of 104 mg/dl, a 2-h postprandial sugar level of 101 mg/dl, a sodium level of 144 mmol/l, a potassium level of 3.7 mmol/l and a chloride level of 106 mmol/l in serum. Urine chemistry revealed that the amount of glucose excreted was 10.8 g/1.73 m2/24 h; however, the levels of the other parameters were unremarkable. Polymerase chain reaction (PCR) sequencing analysis of the SLC5A2 gene from the patient revealed a novel 1 bp deletion mutation, which altered the coding sequence of exon 10 in the transmembrane domain (c.1162delG; Ala388ProfsX48), suggesting an autosomal dominant inheritance pattern. This study identified a novel mutation in the SLC5A2 gene related to a benign clinical characteristic and suggests that the molecular diagnosis of the SLC5A2 gene may be useful for diagnosing renal glucosuria in patients and for deciding intervention measures for their family members.
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Affiliation(s)
- Yong-Wha Lee
- Department of Laboratory Medicine and Genetics, Soonchunhyang University Bucheon Hospital and Soonchunhyang University College of Medicine, Bucheon, Gyeonggi 420-767, Republic of Korea
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Toka HR, Yang J, Zera CA, Duffield JS, Pollak MR, Mount DB. Pregnancy-associated polyuria in familial renal glycosuria. Am J Kidney Dis 2013; 62:1160-4. [PMID: 23871407 DOI: 10.1053/j.ajkd.2013.05.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 05/15/2013] [Indexed: 11/11/2022]
Abstract
A pregnant woman presented at gestational week 28 with loss of consciousness and profound polyuria. Further characterization revealed osmotic diuresis due to massive glycosuria without hyperglycemia. Glycosuria reduced substantially postpartum, from approximately 100 to approximately 30 g/1.73 m2 per day. DNA sequencing analysis of the SLC5A2 gene encoding the renal glucose transporter SGLT2 showed a homozygous frame-shift mutation (occurring after the glutamine at amino acid 168 and leading to premature termination of the protein at amino acid 186) diagnostic of familial renal glycosuria. Pregnant women with familial renal glycosuria can be at risk of profound polyuria during pregnancy due to the associated increase in glycosuria. These findings also have implications for the use of SGLT2 inhibitors in clinical practice.
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Affiliation(s)
- Hakan R Toka
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, MA; Division of Nephrology, Brigham and Women's Hospital, Boston, MA
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Abstract
PURPOSE OF REVIEW Reabsorption of glucose in the proximal tubule occurs predominantly via the sodium glucose cotransporter 2 (SGLT2). There has been intense interest in this transporter as a number of SGLT2 inhibitors have entered clinical development. SGLT2 inhibitors act to lower plasma glucose by promoting glycosuria and this review aims to outline the effect on the diabetic kidney of this hypoglycaemic agent. RECENT FINDINGS This review provides an overview of recent findings in this area: the transcriptional control of SGLT2 expression in human proximal tubular cells implicates a number of cytokines in the alteration of SGLT2 expression; experimental data show that SGLT2 inhibition may correct early detrimental effects of diabetes by reducing proximal tubular sodium and glucose transport, suggesting a possible renoprotective effect independent of the glucose lowering effects of these agents; and the nonglycaemic effects of SGLT2 inhibitors may have an impact on renal outcomes. SUMMARY The available clinical evidence shows consistent reduction in glycaemic parameters and some evidence suggests additional effects including weight loss and mild blood pressure reduction. There are some side effects that warrant further investigation and establishing whether SGLT2 inhibition provides a renal benefit relies on future long-term studies with specific renal end-points.
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Yamaguchi K, Kato M, Suzuki M, Hagita H, Takada M, Ayabe M, Aso Y, Ishigai M, Ikeda S. In vitro-in vivo correlation of the inhibition potency of sodium-glucose cotransporter inhibitors in rat: a pharmacokinetic and pharmacodynamic modeling approach. J Pharmacol Exp Ther 2013; 345:52-61. [PMID: 23386251 DOI: 10.1124/jpet.113.203125] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To evaluate the relationship between the in vitro and in vivo potency of sodium-glucose cotransporter (SGLT) inhibitors, a pharmacokinetic and pharmacodynamic (PK-PD) study was performed using normal rats. A highly selective SGLT2 inhibitor, tofogliflozin, and four other inhibitors with different in vitro inhibition potency to SGLT2 and selectivity toward SGLT2, versus SGLT1 were used as test compounds, and the time courses for urinary glucose excretion (UGE) and the plasma glucose and compound concentrations were monitored after administration of the compounds. A PK-PD analysis of the UGE caused by SGLT inhibition was performed on the basis of a nonlinear parallel tube model that took into consideration the consecutive reabsorption by different glucose transport properties of SGLT2 and SGLT1. The model adequately captured the time course of cumulative UGE caused by SGLT inhibition; then, the in vivo inhibition constants (Ki) of inhibitors for both SGLT1 and SGLT2 were estimated. The in vivo selectivity toward SGLT2 showed a good correlation with the in vitro data (r = 0.985; P < 0.05), with in vivo Ki values for SGLT2 in the range of 0.3-3.4-fold the in vitro data. This suggests that in vitro inhibition potency to both SGLT2 and SGLT1 is reflected in vivo. Furthermore, the complementary role of SGLT1 to SGLT2 and how selectivity toward SGLT2 affects the inhibitory potency for renal glucose reabsorption were discussed using the PK-PD model.
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Affiliation(s)
- Koji Yamaguchi
- Research Division, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka 412-8513, Japan.
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Ohtake Y, Sato T, Kobayashi T, Nishimoto M, Taka N, Takano K, Yamamoto K, Ohmori M, Yamaguchi M, Takami K, Yeu SY, Ahn KH, Matsuoka H, Morikawa K, Suzuki M, Hagita H, Ozawa K, Yamaguchi K, Kato M, Ikeda S. Discovery of tofogliflozin, a novel C-arylglucoside with an O-spiroketal ring system, as a highly selective sodium glucose cotransporter 2 (SGLT2) inhibitor for the treatment of type 2 diabetes. J Med Chem 2012; 55:7828-40. [PMID: 22889351 DOI: 10.1021/jm300884k] [Citation(s) in RCA: 132] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Inhibition of sodium glucose cotransporter 2 (SGLT2) has been proposed as a novel therapeutic approach to treat type 2 diabetes. In our efforts to discover novel inhibitors of SGLT2, we first generated a 3D pharmacophore model based on the superposition of known inhibitors. A search of the Cambridge Structural Database using a series of pharmacophore queries led to the discovery of an O-spiroketal C-arylglucoside scaffold. Subsequent chemical examination combined with computational modeling resulted in the identification of the clinical candidate 16d (CSG452, tofogliflozin), which is currently under phase III clinical trials.
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Affiliation(s)
- Yoshihito Ohtake
- Research Division, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka 412-8513, Japan.
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Familial renal glucosuria: a clinicogenetic study of 23 additional cases. Pediatr Nephrol 2012; 27:1091-5. [PMID: 22314875 DOI: 10.1007/s00467-012-2109-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 12/26/2011] [Accepted: 12/28/2011] [Indexed: 10/14/2022]
Abstract
BACKGROUND Familial renal glucosuria (FRG) is an inherited renal tubular disorder characterized by persistent isolated glucosuria in the absence of hyperglycemia that is caused by mutations in the sodium-glucose cotransporter SGLT2 coding gene, SLC5A2. OBJECTIVE We conducted molecular and phenotype analyses of a cohort of 23 unrelated Korean children with FRG. METHODS Mutational analysis of the SLC5A2 gene was conducted in this multicenter study organized by the Korean Society of Pediatric Nephrology. RESULTS A total of 21 different SLC5A2 mutations were detected, including 19 novel mutations. All patients had at least one mutated allele; ten patients had homozygous or compound heterozygous mutations and 13 patients had a single heterozygous mutation. Most mutations were private. Patients with two mutations were diagnosed earlier with larger amounts of urinary glucose excretion than patients with single mutations. Pedigree analysis data were consistent with the inheritance of a codominant trait with incomplete penetrance. CONCLUSIONS These findings extend the allelic heterogeneity in FRG and confirm previous observations of inheritance and genotype–phenotype correlation in patients with this disease.
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Hao DC, Xiao B, Xiang Y, Dong XW, Xiao PG. Deleterious nonsynonymous single nucleotide polymorphisms in human solute carriers: the first comparison of three prediction methods. Eur J Drug Metab Pharmacokinet 2012; 38:53-62. [DOI: 10.1007/s13318-012-0095-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 04/20/2012] [Indexed: 11/24/2022]
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Suzuki M, Honda K, Fukazawa M, Ozawa K, Hagita H, Kawai T, Takeda M, Yata T, Kawai M, Fukuzawa T, Kobayashi T, Sato T, Kawabe Y, Ikeda S. Tofogliflozin, a potent and highly specific sodium/glucose cotransporter 2 inhibitor, improves glycemic control in diabetic rats and mice. J Pharmacol Exp Ther 2012; 341:692-701. [PMID: 22410641 DOI: 10.1124/jpet.112.191593] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Sodium/glucose cotransporter 2 (SGLT2) is the predominant mediator of renal glucose reabsorption and is an emerging molecular target for the treatment of diabetes. We identified a novel potent and selective SGLT2 inhibitor, tofogliflozin (CSG452), and examined its efficacy and pharmacological properties as an antidiabetic drug. Tofogliflozin competitively inhibited SGLT2 in cells overexpressing SGLT2, and K(i) values for human, rat, and mouse SGLT2 inhibition were 2.9, 14.9, and 6.4 nM, respectively. The selectivity of tofogliflozin toward human SGLT2 versus human SGLT1, SGLT6, and sodium/myo-inositol transporter 1 was the highest among the tested SGLT2 inhibitors under clinical development. Furthermore, no interaction with tofogliflozin was observed in any of a battery of tests examining glucose-related physiological processes, such as glucose uptake, glucose oxidation, glycogen synthesis, hepatic glucose production, glucose-stimulated insulin secretion, and glucosidase reactions. A single oral gavage of tofogliflozin increased renal glucose clearance and lowered the blood glucose level in Zucker diabetic fatty rats. Tofogliflozin also improved postprandial glucose excursion in a meal tolerance test with GK rats. In db/db mice, 4-week tofogliflozin treatment reduced glycated hemoglobin and improved glucose tolerance in the oral glucose tolerance test 4 days after the final administration. No blood glucose reduction was observed in normoglycemic SD rats treated with tofogliflozin. These findings demonstrate that tofogliflozin inhibits SGLT2 in a specific manner, lowers blood glucose levels by increasing renal glucose clearance, and improves pathological conditions of type 2 diabetes with a low hypoglycemic potential.
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Affiliation(s)
- Masayuki Suzuki
- Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka 412-8513, Japan
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Structural Insights into Genetic Variants of Na+/Glucose Cotransporter SGLT1 Causing Glucose–Galactose Malabsorption: vSGLT as a Model Structure. Cell Biochem Biophys 2012; 63:151-8. [DOI: 10.1007/s12013-012-9352-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Grünert SC, Schwab KO, Pohl M, Sass JO, Santer R. Fanconi-Bickel syndrome: GLUT2 mutations associated with a mild phenotype. Mol Genet Metab 2012; 105:433-7. [PMID: 22214819 DOI: 10.1016/j.ymgme.2011.11.200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 11/30/2011] [Accepted: 11/30/2011] [Indexed: 10/14/2022]
Abstract
Fanconi-Bickel syndrome (FBS, OMIM #227810), a congenital disorder of carbohydrate metabolism, is caused by mutations in GLUT2 (SLC2A2), the gene encoding the glucose transporter protein-2. The typical clinical picture is characterized by hepatorenal glycogen accumulation resulting in hepato- and nephromegaly, impaired utilization of glucose and galactose, proximal tubular nephropathy, rickets, and severe short stature. We report on two siblings with FBS and an unusually mild clinical course. A 9.5-year-old boy with failure to thrive was diagnosed at the age of 9 months, his younger sister (4.5 years) was investigated in the first months of life and also diagnosed with FBS. Both patients were found to be compound heterozygous for the novel GLUT2 (SLC2A2) mutations c.457_462delCTTATA (p.153_4delLI) and c.1250C>G (p.P417R). On a diet restricted in free glucose and galactose, both children showed normal growth. Hepatomegaly, nephromegaly and hypophosphatemic rickets have never been observed. Glucosuria and tubular proteinuria were only mild compared to previously reported patients with FBS. This report describes an unusually mild phenotype of FBS expanding the spectrum of this disease. Some clinical signs that have been considered hallmarks of FBS like hepatomegaly and short stature may be absent in this condition. As a consequence, clinicians will have to look for GLUT2 mutations even in patients with isolated glucosuria.
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Affiliation(s)
- Sarah Catharina Grünert
- Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Mathildenstrasse 1, 79106 Freiburg, Germany.
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Tahara A, Kurosaki E, Yokono M, Yamajuku D, Kihara R, Hayashizaki Y, Takasu T, Imamura M, Qun L, Tomiyama H, Kobayashi Y, Noda A, Sasamata M, Shibasaki M. Pharmacological profile of ipragliflozin (ASP1941), a novel selective SGLT2 inhibitor, in vitro and in vivo. Naunyn Schmiedebergs Arch Pharmacol 2011; 385:423-36. [PMID: 22139434 DOI: 10.1007/s00210-011-0713-z] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Accepted: 11/16/2011] [Indexed: 12/11/2022]
Abstract
The pharmacological profile of ipragliflozin (ASP1941; (1S)-1,5-anhydro-1-C-{3-[(1-benzothiophen-2-yl)methyl]-4-fluorophenyl}-D: -glucitol compound with L: -proline (1:1)), a novel SGLT2 selective inhibitor, was investigated. In vitro, the potency of ipragliflozin to inhibit SGLT2 and SGLT1 and stability were assessed. In vivo, the pharmacokinetic and pharmacologic profiles of ipragliflozin were investigated in normal mice, streptozotocin-induced type 1 diabetic rats, and KK-A(y) type 2 diabetic mice. Ipragliflozin potently and selectively inhibited human, rat, and mouse SGLT2 at nanomolar ranges and exhibited stability against intestinal glucosidases. Ipragliflozin showed good pharmacokinetic properties following oral dosing, and dose-dependently increased urinary glucose excretion, which lasted for over 12 h in normal mice. Single administration of ipragliflozin resulted in dose-dependent and sustained antihyperglycemic effects in both diabetic models. In addition, once-daily ipragliflozin treatment over 4 weeks improved hyperglycemia with a concomitant increase in urinary glucose excretion in both diabetic models. In contrast, ipragliflozin at pharmacological doses did not affect normoglycemia, as was the case with glibenclamide, and did not influence intestinal glucose absorption and electrolyte balance. These results suggest that ipragliflozin is an orally active SGLT2 selective inhibitor that induces sustained increases in urinary glucose excretion by inhibiting renal glucose reabsorption, with subsequent antihyperglycemic effect and a low risk of hypoglycemia. Ipragliflozin has, therefore, the therapeutic potential to treat hyperglycemia in diabetes by increasing glucose excretion into urine.
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Affiliation(s)
- Atsuo Tahara
- Drug Discovery Research, Astellas Pharma Inc., 21 Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan.
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Fort PE, Losiewicz MK, Reiter CEN, Singh RSJ, Nakamura M, Abcouwer SF, Barber AJ, Gardner TW. Differential roles of hyperglycemia and hypoinsulinemia in diabetes induced retinal cell death: evidence for retinal insulin resistance. PLoS One 2011; 6:e26498. [PMID: 22046295 PMCID: PMC3202547 DOI: 10.1371/journal.pone.0026498] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 09/27/2011] [Indexed: 01/10/2023] Open
Abstract
Diabetes pathology derives from the combination of hyperglycemia and hypoinsulinemia or insulin resistance leading to diabetic complications including diabetic neuropathy, nephropathy and retinopathy. Diabetic retinopathy is characterized by numerous retinal defects affecting the vasculature and the neuro-retina, but the relative contributions of the loss of retinal insulin signaling and hyperglycemia have never been directly compared. In this study we tested the hypothesis that increased retinal insulin signaling and glycemic normalization would exert differential effects on retinal cell survival and retinal physiology during diabetes. We have demonstrated in this study that both subconjunctival insulin administration and systemic glycemic reduction using the sodium-glucose linked transporter inhibitor phloridzin affected the regulation of retinal cell survival in diabetic rats. Both treatments partially restored the retinal insulin signaling without increasing plasma insulin levels. Retinal transcriptomic and histological analysis also clearly demonstrated that local administration of insulin and systemic glycemia normalization use different pathways to counteract the effects of diabetes on the retina. While local insulin primarily affected inflammation-associated pathways, systemic glycemic control affected pathways involved in the regulation of cell signaling and metabolism. These results suggest that hyperglycemia induces resistance to growth factor action in the retina and clearly demonstrate that both restoration of glycemic control and retinal insulin signaling can act through different pathways to both normalize diabetes-induced retinal abnormality and prevent vision loss.
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Affiliation(s)
- Patrice E Fort
- Kellogg Eye Center, University of Michigan, Ophthalmology and Visual Sciences Department, Ann Arbor, Michigan, United States of America.
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Yamaguchi K, Kato M, Suzuki M, Asanuma K, Aso Y, Ikeda S, Ishigai M. Pharmacokinetic and pharmacodynamic modeling of the effect of an sodium-glucose cotransporter inhibitor, phlorizin, on renal glucose transport in rats. Drug Metab Dispos 2011; 39:1801-7. [PMID: 21712434 DOI: 10.1124/dmd.111.040048] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A pharmacokinetic and pharmacodynamic (PK-PD) model for the inhibitory effect of sodium-glucose cotransporter (SGLT) inhibitors on renal glucose reabsorption was developed to predict in vivo efficacy. First, using the relationship between renal glucose clearance and plasma glucose level in rats and both the glucose affinity and transport capacity obtained from in vitro vesicle experiments, a pharmacodynamic model analysis was performed based on a nonlinear parallel tube model to express the renal glucose transport mediated by SGLT1 and SGLT2. This model suitably expressed the relationship between plasma glucose level and renal glucose excretion. A PK-PD model was developed next to analyze the inhibitory effect of phlorizin on renal glucose reabsorption. The PK-PD model analysis was performed using averaged concentrations of both the drug and glucose in plasma and the corresponding renal glucose clearance. The model suitably expressed the concentration-dependent inhibitory effect of phlorizin on renal glucose reabsorption. The in vivo inhibition constants of phlorizin for SGLT in rats were estimated to be 67 nM for SGLT1 and 252 nM for SGLT2, which are similar to the in vitro data reported previously. This suggests that the in vivo efficacy of SGLT inhibitors could be predicted from an in vitro study based on the present PK-PD model. The present model is based on physiological and biochemical parameters and, therefore, would be helpful in understanding individual differences in the efficacy of an SGLT inhibitor.
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Affiliation(s)
- Koji Yamaguchi
- Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka 412-8513, Japan.
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