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Lee D, Hong JH. Chloride/Multiple Anion Exchanger SLC26A Family: Systemic Roles of SLC26A4 in Various Organs. Int J Mol Sci 2024; 25:4190. [PMID: 38673775 PMCID: PMC11050216 DOI: 10.3390/ijms25084190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 03/31/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
Solute carrier family 26 member 4 (SLC26A4) is a member of the SLC26A transporter family and is expressed in various tissues, including the airway epithelium, kidney, thyroid, and tumors. It transports various ions, including bicarbonate, chloride, iodine, and oxalate. As a multiple-ion transporter, SLC26A4 is involved in the maintenance of hearing function, renal function, blood pressure, and hormone and pH regulation. In this review, we have summarized the various functions of SLC26A4 in multiple tissues and organs. Moreover, the relationships between SLC26A4 and other channels, such as cystic fibrosis transmembrane conductance regulator, epithelial sodium channel, and sodium chloride cotransporter, are highlighted. Although the modulation of SLC26A4 is critical for recovery from malfunctions of various organs, development of specific inducers or agonists of SLC26A4 remains challenging. This review contributes to providing a better understanding of the role of SLC26A4 and development of therapeutic approaches for the SLC26A4-associated hearing loss and SLC26A4-related dysfunction of various organs.
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Affiliation(s)
| | - Jeong Hee Hong
- Department of Health Sciences and Technology, GAIHST (Gachon Advanced Institute for Health Sciences and Technology), Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 155 Getbeolro, Yeonsu-gu, Incheon 21999, Republic of Korea;
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2
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Chen T, Qian B, Zou J, Luo P, Zou J, Li W, Chen Q, Zheng L. Oxalate as a potent promoter of kidney stone formation. Front Med (Lausanne) 2023; 10:1159616. [PMID: 37342493 PMCID: PMC10278359 DOI: 10.3389/fmed.2023.1159616] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 05/09/2023] [Indexed: 06/23/2023] Open
Abstract
Kidney stones are among the most prevalent urological diseases, with a high incidence and recurrence rate. Treating kidney stones has been greatly improved by the development of various minimally invasive techniques. Currently, stone treatment is relatively mature. However, most current treatment methods are limited to stones and cannot effectively reduce their incidence and recurrence. Therefore, preventing disease occurrence, development, and recurrence after treatment, has become an urgent issue. The etiology and pathogenesis of stone formation are key factors in resolving this issue. More than 80% of kidney stones are calcium oxalate stones. Several studies have studied the formation mechanism of stones from the metabolism of urinary calcium, but there are few studies on oxalate, which plays an equally important role in stone formation. Oxalate and calcium play equally important roles in calcium oxalate stones, whereas the metabolism and excretion disorders of oxalate play a crucial role in their occurrence. Therefore, starting from the relationship between renal calculi and oxalate metabolism, this work reviews the occurrence of renal calculi, oxalate absorption, metabolism, and excretion mechanisms, focusing on the key role of SLC26A6 in oxalate excretion and the regulatory mechanism of SLC26A6 in oxalate transport. This review provides some new clues for the mechanism of kidney stones from the perspective of oxalate to improve the understanding of the role of oxalate in the formation of kidney stones and to provide suggestions for reducing the incidence and recurrence rate of kidney stones.
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Affiliation(s)
- Tao Chen
- The First Clinical College, Gannan Medical University, Ganzhou, Jiangxi, China
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
- Key Laboratory of Urology and Andrology of Ganzhou, Ganzhou, Jiangxi, China
| | - Biao Qian
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
- Key Laboratory of Urology and Andrology of Ganzhou, Ganzhou, Jiangxi, China
| | - Junrong Zou
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
- Key Laboratory of Urology and Andrology of Ganzhou, Ganzhou, Jiangxi, China
| | - Peiyue Luo
- The First Clinical College, Gannan Medical University, Ganzhou, Jiangxi, China
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
- Key Laboratory of Urology and Andrology of Ganzhou, Ganzhou, Jiangxi, China
| | - Jun Zou
- The First Clinical College, Gannan Medical University, Ganzhou, Jiangxi, China
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
- Key Laboratory of Urology and Andrology of Ganzhou, Ganzhou, Jiangxi, China
| | - Wei Li
- The First Clinical College, Gannan Medical University, Ganzhou, Jiangxi, China
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
- Key Laboratory of Urology and Andrology of Ganzhou, Ganzhou, Jiangxi, China
| | - Qi Chen
- The First Clinical College, Gannan Medical University, Ganzhou, Jiangxi, China
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
- Key Laboratory of Urology and Andrology of Ganzhou, Ganzhou, Jiangxi, China
| | - Liying Zheng
- Department of Graduate, The First Affiliated Hospital of Ganna Medical University, Ganzhou, Jiangxi, China
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Demoulin N, Aydin S, Gillion V, Morelle J, Jadoul M. Pathophysiology and Management of Hyperoxaluria and Oxalate Nephropathy: A Review. Am J Kidney Dis 2022; 79:717-727. [PMID: 34508834 DOI: 10.1053/j.ajkd.2021.07.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 07/27/2021] [Indexed: 01/11/2023]
Abstract
Hyperoxaluria results from either inherited disorders of glyoxylate metabolism leading to hepatic oxalate overproduction (primary hyperoxaluria), or increased intestinal oxalate absorption (secondary hyperoxaluria). Hyperoxaluria may lead to urinary supersaturation of calcium oxalate and crystal formation, causing urolithiasis and deposition of calcium oxalate crystals in the kidney parenchyma, a condition termed oxalate nephropathy. Considerable progress has been made in the understanding of pathophysiological mechanisms leading to hyperoxaluria and oxalate nephropathy, whose diagnosis is frequently delayed and prognosis too often poor. Fortunately, novel promising targeted therapeutic approaches are on the horizon in patients with primary hyperoxaluria. Patients with secondary hyperoxaluria frequently have long-standing hyperoxaluria-enabling conditions, a fact suggesting the role of triggers of acute kidney injury such as dehydration. Current standard of care in these patients includes management of the underlying cause, high fluid intake, and use of calcium supplements. Overall, prompt recognition of hyperoxaluria and associated oxalate nephropathy is crucial because optimal management may improve outcomes.
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Affiliation(s)
- Nathalie Demoulin
- Division of Nephrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium; Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium.
| | - Selda Aydin
- Department of Pathology, Cliniques Universitaires Saint-Luc, Brussels, Belgium; Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Valentine Gillion
- Division of Nephrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium; Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Johann Morelle
- Division of Nephrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium; Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Michel Jadoul
- Division of Nephrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium; Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
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4
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Yang X, Yao S, An J, Jin H, Wang H, Tuo B. SLC26A6 and NADC‑1: Future direction of nephrolithiasis and calculus‑related hypertension research (Review). Mol Med Rep 2021; 24:745. [PMID: 34458928 DOI: 10.3892/mmr.2021.12385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/30/2021] [Indexed: 11/06/2022] Open
Abstract
Nephrolithiasis is the most common type of urinary system disease in developed countries, with high morbidity and recurrence rates. Nephrolithiasis is a serious health problem, which eventually leads to the loss of renal function and is closely related to hypertension. Modern medicine has adopted minimally invasive surgery for the management of kidney stones, but this does not resolve the root of the problem. Thus, nephrolithiasis remains a major public health issue, the causes of which remain largely unknown. Researchers have attempted to determine the causes and therapeutic targets of kidney stones and calculus‑related hypertension. Solute carrier family 26 member 6 (SLC26A6), a member of the well‑conserved solute carrier family 26, is highly expressed in the kidney and intestines, and it primarily mediates the transport of various anions, including OXa2‑, HCO3‑, Cl‑ and SO42‑, amongst others. Na+‑dependent dicarboxylate‑1 (NADC‑1) is the Na+‑carboxylate co‑transporter of the SLC13 gene family, which primarily mediates the co‑transport of Na+ and tricarboxylic acid cycle intermediates, such as citrate and succinate, amongst others. Studies have shown that Ca2+ oxalate kidney stones are the most prevalent type of kidney stones. Hyperoxaluria and hypocitraturia notably increase the risk of forming Ca2+ oxalate kidney stones, and the increase in succinate in the juxtaglomerular device can stimulate renin secretion and lead to hypertension. Whilst it is known that it is important to maintain the dynamic equilibrium of oxalate and citrate in the kidney, the synergistic molecular mechanisms underlying the transport of oxalate and citrate across kidney epithelial cells have undergone limited investigations. The present review examines the results from early reports studying oxalate transport and citrate transport in the kidney, describing the synergistic molecular mechanisms of SLC26A6 and NADC‑1 in the process of nephrolithiasis formation. A growing body of research has shown that nephrolithiasis is intricately associated with hypertension. Additionally, the recent investigations into the mediation of succinate via regulation of the synergistic molecular mechanism between the SLC26A6 and NADC‑1 transporters is summarized, revealing their functional role and their close association with the inositol triphosphate receptor‑binding protein to regulate blood pressure.
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Affiliation(s)
- Xingyue Yang
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Shun Yao
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Jiaxing An
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Hai Jin
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Hui Wang
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Biguang Tuo
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
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5
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Seifter JL. Body Fluid Compartments, Cell Membrane Ion Transport, Electrolyte Concentrations, and Acid-Base Balance. Semin Nephrol 2020; 39:368-379. [PMID: 31300092 DOI: 10.1016/j.semnephrol.2019.04.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Measurements made in the blood, part of the extracellular compartment, are used in the clinical assessment of acid-base disorders; however, intracellular events determine much of the metabolic importance of these disorders. Intracellular and interstitial compartment acid-base balance is complex and varies in different tissues. This review considers the determination of extracellular pH in the context of ion transport processes at the interface of cells and the interstitial fluid, and between epithelial cells lining the transcellular contents of the gastrointestinal and urinary tracts that open to the external environment. A further consideration is the role of these membrane transporters in the generation of acid-base disorders and the associated disruption of electrolyte balance. This review suggests a process of internal and external balance for pH regulation similar to that of potassium, and considers the role of secretory gastrointestinal epithelia and renal epithelia with respect to normal pH homeostasis and clinical disorders. Electroneutrality of electrolytes in the extracellular fluid is a fundamental feature of reciprocal changes in Cl- or non-Cl- anions and HCO3-. Normal mechanisms for protecting cell pH and producing normal gastrointestinal and renal secretions in healthy states also may result in disease when abnormal. In a similar manner, organic anions such as ketoacid anions and lactate, normally transported as fuels between organs, result in acid-base disturbances in disease. Understanding the genomic basis of these transporters may contribute to specific treatments.
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6
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Han Q, Yang C, Lu J, Zhang Y, Li J. Metabolism of Oxalate in Humans: A Potential Role Kynurenine Aminotransferase/Glutamine Transaminase/Cysteine Conjugate Beta-lyase Plays in Hyperoxaluria. Curr Med Chem 2019; 26:4944-4963. [PMID: 30907303 DOI: 10.2174/0929867326666190325095223] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/17/2019] [Accepted: 02/22/2019] [Indexed: 11/22/2022]
Abstract
Hyperoxaluria, excessive urinary oxalate excretion, is a significant health problem worldwide. Disrupted oxalate metabolism has been implicated in hyperoxaluria and accordingly, an enzymatic disturbance in oxalate biosynthesis can result in the primary hyperoxaluria. Alanine glyoxylate aminotransferase-1 and glyoxylate reductase, the enzymes involving glyoxylate (precursor for oxalate) metabolism, have been related to primary hyperoxalurias. Some studies suggest that other enzymes such as glycolate oxidase and alanine glyoxylate aminotransferase-2 might be associated with primary hyperoxaluria as well, but evidence of a definitive link is not strong between the clinical cases and gene mutations. There are still some idiopathic hyperoxalurias, which require a further study for the etiologies. Some aminotransferases, particularly kynurenine aminotransferases, can convert glyoxylate to glycine. Based on biochemical and structural characteristics, expression level, subcellular localization of some aminotransferases, a number of them appear able to catalyze the transamination of glyoxylate to glycine more efficiently than alanine glyoxylate aminotransferase-1. The aim of this minireview is to explore other undermining causes of primary hyperoxaluria and stimulate research toward achieving a comprehensive understanding of underlying mechanisms leading to the disease. Herein, we reviewed all aminotransferases in the liver for their functions in glyoxylate metabolism. Particularly, kynurenine aminotransferase-I and III were carefully discussed regarding their biochemical and structural characteristics, cellular localization, and enzyme inhibition. Kynurenine aminotransferase-III is, so far, the most efficient putative mitochondrial enzyme to transaminate glyoxylate to glycine in mammalian livers, might be an interesting enzyme to look over in hyperoxaluria etiology of primary hyperoxaluria and should be carefully investigated for its involvement in oxalate metabolism.
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Affiliation(s)
- Qian Han
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan 570228. China
| | - Cihan Yang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou, Hainan 570228. China
| | - Jun Lu
- Central South University Xiangya School of Medicine Affiliated Haikou People's Hospital, Haikou, Hainan 570208. China
| | - Yinai Zhang
- Central South University Xiangya School of Medicine Affiliated Haikou People's Hospital, Haikou, Hainan 570208. China
| | - Jianyong Li
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061. United States
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7
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Huang Y, Peng Q, Bao M, Liu C, Wu K, Zhou S. Biochemical metabolic levels and vitamin D receptor FokⅠ gene polymorphisms in Uyghur children with urolithiasis. PLoS One 2019; 14:e0212183. [PMID: 30742686 PMCID: PMC6370244 DOI: 10.1371/journal.pone.0212183] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 01/29/2019] [Indexed: 02/05/2023] Open
Abstract
Because of lacking studies of urolithiasis in children, we detected the biochemical metabolic levels and FokⅠ polymorphisms in the vitamin D receptor (VDR) in Uyghur children with urolithiasis, and evaluated the associations of biochemical metabolic levels with FokⅠ genotypes. We included 142 Uyghur children (108 males) under age 14 years with a diagnosis of urolithiasis and 238 Uyghur children (154 males) under age 14 years without a history of urolithiasis as controls. Baseline information and data for serum and urine parameters were obtained from medical records. PCR-restriction fragment length polymorphism (PCR-RFLP) was used to analyze the VDR FokⅠ polymorphisms. In univariate analyses adjusting for age and sex, carbon dioxide combining power (CO2CP) (odds ratio [OR] = 1.13, 95% confidence interval [CI]: 1.07-1.19), serum magnesium (Mg) (OR = 1.27, 95% CI: 1.03-1.56) and serum chlorine (Cl) (OR = 0.93, 95% CI: 0.88-0.97) were related to Uyghur children urolithiasis risk. A multiple logistic regression model showed CO2CP (OR = 1.17, 95% CI: 1.09-1.26), levels of uric acid (OR = 1.01, 95% CI: 1.00-1.01) and serum sodium (Na) (OR = 0.90, 95% CI: 0.82-0.99) were associated with pediatric urolithiasis. The risk of urolithiasis was increased with the F versus f allele overall (OR = 1.42; 95% CI: 1.01-2.00) and for males (OR = 1.52, 95% CI: 1.02-2.27). However, metabolic levels did not differ by FokⅠ genotypes. In our population, CO2CP and levels of uric acid and serum Na as well as polymorphism of the F allele of the VDR FokⅠ may provide important clues to evaluate the risk of urolithiasis in Uyghur children.
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Affiliation(s)
- Yuanni Huang
- Department of Preventive Medicine, Shantou University Medical College, Shantou, Guangdong, China
| | - Qing Peng
- Department of Hepatobiliary Surgery II, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, China
| | - Mian Bao
- Department of Preventive Medicine, Shantou University Medical College, Shantou, Guangdong, China
| | - Caixia Liu
- Department of Preventive Medicine, Shantou University Medical College, Shantou, Guangdong, China
| | - Kusheng Wu
- Department of Preventive Medicine, Shantou University Medical College, Shantou, Guangdong, China
- * E-mail: (KW); (SZ)
| | - Shuqin Zhou
- Department of Anesthesiology, the First People’s Hospital of Kashi, Kashi, Xinjiang, China
- Department of Anesthesiology, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, China
- * E-mail: (KW); (SZ)
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Sex-independent expression of chloride/formate exchanger Cfex (Slc26a6) in rat pancreas, small intestine, and liver, and male-dominant expression in kidneys. Arh Hig Rada Toksikol 2018; 69:286-303. [PMID: 30864378 DOI: 10.2478/aiht-2018-69-3157] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 11/01/2018] [Indexed: 01/03/2023] Open
Abstract
Chloride/formate exchanger (CFEX; SLC26A6) mediates oxalate transport in various mammalian organs. Studies in Cfex knockout mice indicated its possible role in development of male-dominant hyperoxaluria and oxalate urolithiasis. Rats provide an important model for studying this pathophysiological condition, but data on Cfex (rCfex) localisation and regulation in their organs are limited. Here we applied the RT-PCR and immunochemical methods to investigate rCfex mRNA and protein expression and regulation by sex hormones in the pancreas, small intestine, liver, and kidneys from intact prepubertal and adult as well as gonadectomised adult rats treated with sex hormones. rCfex cDNA-transfected HEK293 cells were used to confirm the specificity of the commercial anti-CFEX antibody. Various biochemical parameters were measured in 24-h urine collected in metabolic cages. rCfex mRNA and related protein expression varied in all tested organs. Sex-independent expression of the rCfex protein was detected in pancreatic intercalated ducts (apical domain), small intestinal enterocytes (brush-border membrane; duodenum > jejunum > ileum), and hepatocytes (canalicular membrane). In kidneys, the rCfex protein was immunolocalised to the proximal tubule brush-border with segment-specific pattern (S1=S2<S3), and both rCfex mRNA and protein expression exhibited male-dominant sex differences driven by stimulatory effects of androgens after puberty. However, urinary oxalate excretion was unrelated to renal rCfex protein expression. While the effect of male-dominant expression of rCfex in renal proximal tubules on urine oxalate excretion remains unknown, its expression in the hepatocyte canalicular membrane may be a pathway of oxalate elimination via bile.
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Knauf F, Velazquez H, Pfann V, Jiang Z, Aronson PS. Characterization of renal NaCl and oxalate transport in Slc26a6 -/- mice. Am J Physiol Renal Physiol 2018; 316:F128-F133. [PMID: 30427220 DOI: 10.1152/ajprenal.00309.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The apical membrane Cl-/oxalate exchanger SLC26A6 has been demonstrated to play a role in proximal tubule NaCl transport based on studies in microperfused tubules. The present study is directed at characterizing the role of SLC26A6 in NaCl homeostasis in vivo under physiological conditions. Free-flow micropuncture studies revealed that volume and Cl- absorption were similar in surface proximal tubules of wild-type and Slc26a6-/- mice. Moreover, the increments in urine flow rate and sodium excretion following thiazide and furosemide infusion were identical in wild-type and Slc26a6-/- mice, indicating no difference in NaCl delivery out of the proximal tubule. The absence of an effect of deletion of SLC26A6 on NaCl homeostasis was further supported by the absence of lower blood pressure in Slc26a6-/- compared with wild-type mice on normal or low-salt diets. Moreover, raising plasma and urine oxalate by feeding mice a diet enriched in soluble oxalate did not affect mean blood pressure. In contrast to the lack of effect of SLC26A6 deletion on NaCl homeostasis, fractional excretion of oxalate was reduced from 1.6 in wild-type mice to 0.7 in Slc26a6-/- mice. We conclude that, although SLC26A6 is dispensable for renal NaCl homeostasis, it is required for net renal secretion of oxalate.
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Affiliation(s)
- Felix Knauf
- Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, Berlin , Germany.,Department of Internal Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Heino Velazquez
- Department of Internal Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Victoria Pfann
- Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, Berlin , Germany.,Department of Internal Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Zhirong Jiang
- Department of Internal Medicine, Yale University School of Medicine , New Haven, Connecticut
| | - Peter S Aronson
- Department of Internal Medicine, Yale University School of Medicine , New Haven, Connecticut.,Department of Cellular and Molecular Physiology, Yale University School of Medicine , New Haven, Connecticut
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Abstract
Shigella is an intracellular pathogen that invades the human host cell cytosol and exploits intracellular nutrients for growth, enabling the bacterium to create its own metabolic niche. For Shigella to effectively invade and replicate within the host cytoplasm, it must sense and adapt to changing environmental conditions; however, the mechanisms and signals sensed by S. flexneri are largely unknown. We have found that the secreted Shigella metabolism by-product formate regulates Shigella intracellular virulence gene expression and its ability to spread among epithelial cells. We propose that Shigella senses formate accumulation in the host cytosol as a way to determine intracellular Shigella density and regulate secreted virulence factors accordingly, enabling spatiotemporal regulation of effectors important for dampening the host immune response. The intracellular human pathogen Shigella flexneri invades the colon epithelium, replicates to high cell density within the host cell, and then spreads to adjacent epithelial cells. When S. flexneri gains access to the host cytosol, the bacteria metabolize host cytosolic carbon using glycolysis and mixed acid fermentation, producing formate as a by-product. We show that S. flexneri infection results in the accumulation of formate within the host cell. Loss of pyruvate formate lyase (PFL; ΔpflB), which converts pyruvate to acetyl coenzyme A (CoA) and formate, eliminates S. flexneri formate production and reduces the ability of S. flexneri to form plaques in epithelial cell monolayers. This defect in PFL does not decrease the intracellular growth rate of S. flexneri; rather, it affects cell-to-cell spread. The S. flexneri ΔpflB mutant plaque defect is complemented by supplying exogenous formate; conversely, deletion of the S. flexneri formate dehydrogenase gene fdnG increases host cell formate accumulation and S. flexneri plaque size. Furthermore, exogenous formate increases plaque size of the wild-type (WT) S. flexneri strain and promotes S. flexneri cell-to-cell spread. We also demonstrate that formate increases the expression of S. flexneri virulence genes icsA and ipaJ. Intracellular S. flexneriicsA and ipaJ expression is dependent on the presence of formate, and ipaJ expression correlates with S. flexneri intracellular density during infection. Finally, consistent with elevated ipaJ, we show that formate alters S. flexneri-infected host interferon- and tumor necrosis factor (TNF)-stimulated gene expression. We propose that Shigella-derived formate is an intracellular signal that modulates virulence in response to bacterial metabolism.
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11
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Seifter JL, Chang HY. Extracellular Acid-Base Balance and Ion Transport Between Body Fluid Compartments. Physiology (Bethesda) 2018; 32:367-379. [PMID: 28814497 DOI: 10.1152/physiol.00007.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 07/05/2017] [Accepted: 07/06/2017] [Indexed: 01/18/2023] Open
Abstract
Clinical assessment of acid-base disorders depends on measurements made in the blood, part of the extracellular compartment. Yet much of the metabolic importance of these disorders concerns intracellular events. Intracellular and interstitial compartment acid-base balance is complex and heterogeneous. This review considers the determinants of the extracellular fluid pH related to the ion transport processes at the interface of cells and the interstitial fluid, and between epithelial cells lining the transcellular contents of the gastrointestinal and urinary tracts that open to the external environment. The generation of acid-base disorders and the associated disruption of electrolyte balance are considered in the context of these membrane transporters. This review suggests a process of internal and external balance for pH regulation, similar to that of potassium. The role of secretory gastrointestinal epithelia and renal epithelia with respect to normal pH homeostasis and clinical disorders are considered. Electroneutrality of electrolytes in the ECF is discussed in the context of reciprocal changes in Cl- or non Cl- anions and [Formula: see text].
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12
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Mukaibo T, Munemasa T, George AT, Tran DT, Gao X, Herche JL, Masaki C, Shull GE, Soleimani M, Melvin JE. The apical anion exchanger Slc26a6 promotes oxalate secretion by murine submandibular gland acinar cells. J Biol Chem 2018; 293:6259-6268. [PMID: 29530983 PMCID: PMC5925796 DOI: 10.1074/jbc.ra118.002378] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/08/2018] [Indexed: 12/15/2022] Open
Abstract
The solute carrier family 26 (SLC26) gene family encodes at least 10 different anion exchangers. SLC26 member 6 (SLC26A6 or CFEX/PAT-1) and the cystic fibrosis transmembrane conductance regulator (CFTR) co-localize to the apical membrane of pancreatic duct cells, where they act in concert to drive HCO3- and fluid secretion. In contrast, in the small intestine, SLC26A6 serves as the major pathway for oxalate secretion. However, little is known about the function of Slc26a6 in murine salivary glands. Here, RNA sequencing-based transcriptional profiling and Western blots revealed that Slc26a6 is highly expressed in mouse submandibular and sublingual salivary glands. Slc26a6 localized to the apical membrane of salivary gland acinar cells with no detectable immunostaining in the ducts. CHO-K1 cells transfected with mouse Slc26a6 exchanged Cl- for oxalate and HCO3-, whereas two other anion exchangers known to be expressed in salivary gland acinar cells, Slc4a4 and Slc4a9, mediated little, if any, Cl-/oxalate exchange. Of note, both Cl-/oxalate exchange and Cl-/HCO3- exchange were significantly reduced in acinar cells isolated from the submandibular glands of Slc26a6-/- mice. Oxalate secretion in submandibular saliva also decreased significantly in Slc26a6-/- mice, but HCO3- secretion was unaffected. Taken together, our findings indicate that Slc26a6 is located at the apical membrane of salivary gland acinar cells, where it mediates Cl-/oxalate exchange and plays a critical role in the secretion of oxalate into saliva.
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Affiliation(s)
- Taro Mukaibo
- From the Secretory Mechanisms and Dysfunctions Section and
- the Department of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Kitakyushu, Fukuoka 803-8580, Japan
| | - Takashi Munemasa
- From the Secretory Mechanisms and Dysfunctions Section and
- the Department of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Kitakyushu, Fukuoka 803-8580, Japan
| | - Alvin T George
- From the Secretory Mechanisms and Dysfunctions Section and
| | - Duy T Tran
- Biological Chemistry Section, NIDCR, National Institutes of Health, Bethesda, Maryland 20892
| | - Xin Gao
- From the Secretory Mechanisms and Dysfunctions Section and
- the Joint Institute for Food Safety and Applied Nutrition, University of Maryland, College Park, Maryland 20742, and
| | - Jesse L Herche
- From the Secretory Mechanisms and Dysfunctions Section and
| | - Chihiro Masaki
- the Department of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Kitakyushu, Fukuoka 803-8580, Japan
| | - Gary E Shull
- Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | | | - James E Melvin
- From the Secretory Mechanisms and Dysfunctions Section and
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13
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Abstract
Formate, the only non-tetrahydrofolate (THF)-linked intermediate in one-carbon metabolism, is produced in mammals from a variety of metabolic sources. It occurs in serum of adults at a concentration of approximately 30 μM. Its principal function lies as a source of one-carbon groups for the synthesis of 10-formyl-THF and other one-carbon intermediates; these are primarily used for purine synthesis, thymidylate synthesis, and the provision of methyl groups for synthetic, regulatory, and epigenetic methylation reactions. Although formate is largely produced in mitochondria, these functions mostly occur in the cytoplasm and nucleus. Formate plays a significant role in embryonic development, as evidenced by the effectiveness of formate in the pregnant dam's drinking water on the incidence of neural tube defects in some genetic models. High formate concentrations in fetal lambs may indicate a role in fetal development and suggest that extracellular formate may play a role in the interorgan distribution of one-carbon groups.
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Affiliation(s)
- Margaret E Brosnan
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X9, Canada;
| | - John T Brosnan
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X9, Canada;
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14
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Vasudevan V, Samson P, Smith AD, Okeke Z. The genetic framework for development of nephrolithiasis. Asian J Urol 2016; 4:18-26. [PMID: 29264202 PMCID: PMC5730897 DOI: 10.1016/j.ajur.2016.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 07/12/2016] [Indexed: 11/24/2022] Open
Abstract
Over 1%–15% of the population worldwide is affected by nephrolithiasis, which remains the most common and costly disease that urologists manage today. Identification of at-risk individuals remains a theoretical and technological challenge. The search for monogenic causes of stone disease has been largely unfruitful and a technological challenge; however, several candidate genes have been implicated in the development of nephrolithiasis. In this review, we will review current data on the genetic inheritance of stone disease, as well as investigate the evolving role of genetic analysis and counseling in the management of nephrolithiasis.
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Affiliation(s)
- Vinaya Vasudevan
- Smith Institute for Urology, Hofstra Northwell School of Medicine, Lake Success, NY, USA
| | - Patrick Samson
- Smith Institute for Urology, Hofstra Northwell School of Medicine, Lake Success, NY, USA
| | - Arthur D Smith
- Smith Institute for Urology, Hofstra Northwell School of Medicine, Lake Success, NY, USA
| | - Zeph Okeke
- Smith Institute for Urology, Hofstra Northwell School of Medicine, Lake Success, NY, USA
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15
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Breljak D, Brzica H, Vrhovac I, Micek V, Karaica D, Ljubojević M, Sekovanić A, Jurasović J, Rašić D, Peraica M, Lovrić M, Schnedler N, Henjakovic M, Wegner W, Burckhardt G, Burckhardt BC, Sabolić I. In female rats, ethylene glycol treatment elevates protein expression of hepatic and renal oxalate transporter sat-1 (Slc26a1) without inducing hyperoxaluria. Croat Med J 2016; 56:447-59. [PMID: 26526882 PMCID: PMC4655930 DOI: 10.3325/cmj.2015.56.447] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Aim To investigate whether the sex-dependent expression of hepatic and renal oxalate transporter sat-1 (Slc26a1) changes in a rat model of ethylene glycol (EG)-induced hyperoxaluria. Methods Rats were given tap water (12 males and 12 females; controls) or EG (12 males and 12 females; 0.75% v/v in tap water) for one month. Oxaluric state was confirmed by biochemical parameters in blood plasma, urine, and tissues. Expression of sat-1 and rate-limiting enzymes of oxalate synthesis, alcohol dehydrogenase 1 (Adh1) and hydroxy-acid oxidase 1 (Hao1), was determined by immunocytochemistry (protein) and/or real time reverse transcription polymerase chain reaction (mRNA). Results EG-treated males had significantly higher (in μmol/L; mean ± standard deviation) plasma (59.7 ± 27.2 vs 12.9 ± 4.1, P < 0.001) and urine (3716 ± 1726 vs 241 ± 204, P < 0.001) oxalate levels, and more abundant oxalate crystaluria than controls, while the liver and kidney sat-1 protein and mRNA expression did not differ significantly between these groups. EG-treated females, in comparison with controls had significantly higher (in μmol/L) serum oxalate levels (18.8 ± 2.9 vs 11.6 ± 4.9, P < 0.001), unchanged urine oxalate levels, low oxalate crystaluria, and significantly higher expression (in relative fluorescence units) of the liver (1.59 ± 0.61 vs 0.56 ± 0.39, P = 0.006) and kidney (1.77 ± 0.42 vs 0.69 ± 0.27, P < 0.001) sat-1 protein, but not mRNA. The mRNA expression of Adh1 was female-dominant and that of Hao1 male-dominant, but both were unaffected by EG treatment. Conclusions An increased expression of hepatic and renal oxalate transporting protein sat-1 in EG-treated female rats could protect from hyperoxaluria and oxalate urolithiasis.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Ivan Sabolić
- Ivan Sabolić, Molecular Toxicology, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 10000 Zagreb, Croatia,
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16
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Whittamore JM, Hatch M. Chronic metabolic acidosis reduces urinary oxalate excretion and promotes intestinal oxalate secretion in the rat. Urolithiasis 2015; 43:489-99. [DOI: 10.1007/s00240-015-0801-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 06/30/2015] [Indexed: 11/30/2022]
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17
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Ohana E. Transepithelial ion transport across duct cells of the salivary gland. Oral Dis 2013; 21:826-35. [DOI: 10.1111/odi.12201] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 09/24/2013] [Accepted: 09/25/2013] [Indexed: 01/16/2023]
Affiliation(s)
- E Ohana
- Epithelial Signaling and Transport Section; Molecular Physiology and Therapeutics Branch; National Institute of Dental and Craniofacial Research; National Institutes of Health; Bethesda MD USA
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18
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Abstract
Chloride transport along the nephron is one of the key actions of the kidney that regulates extracellular volume and blood pressure. To maintain steady state, the kidney needs to reabsorb the vast majority of the filtered load of chloride. This is accomplished by the integrated function of sequential chloride transport activities along the nephron. The detailed mechanisms of transport in each segment generate unique patterns of interactions between chloride and numerous other individual components that are transported by the kidney. Consequently, chloride transport is inextricably intertwined with that of sodium, potassium, protons, calcium, and water. These interactions not only allow for exquisitely precise regulation but also determine the particular patterns in which the system can fail in disease states.
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Affiliation(s)
- John C Edwards
- UNC Kidney Center and the Departments of Medicine and Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
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19
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Ohana E, Shcheynikov N, Moe OW, Muallem S. SLC26A6 and NaDC-1 transporters interact to regulate oxalate and citrate homeostasis. J Am Soc Nephrol 2013; 24:1617-26. [PMID: 23833257 DOI: 10.1681/asn.2013010080] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The combination of hyperoxaluria and hypocitraturia can trigger Ca(2+)-oxalate stone formation, even in the absence of hypercalciuria, but the molecular mechanisms that control urinary oxalate and citrate levels are not understood completely. Here, we examined the relationship between the oxalate transporter SLC26A6 and the citrate transporter NaDC-1 in citrate and oxalate homeostasis. Compared with wild-type mice, Slc26a6-null mice exhibited increased renal and intestinal sodium-dependent succinate uptake, as well as urinary hyperoxaluria and hypocitraturia, but no change in urinary pH, indicating enhanced transport activity of NaDC-1. When co-expressed in Xenopus oocytes, NaDC-1 enhanced Slc26a6 transport activity. In contrast, Slc26a6 inhibited NaDC-1 transport activity in an activity dependent manner to restricted tubular citrate absorption. Biochemical and physiologic analysis revealed that the STAS domain of Slc26a6 and the first intracellular loop of NaDC-1 mediated both the physical and functional interactions of these transporters. These findings reveal a molecular pathway that senses and tightly regulates oxalate and citrate levels and may control Ca(2+)-oxalate stone formation.
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Affiliation(s)
- Ehud Ohana
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, and
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20
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Hirata T, Cabrero P, Berkholz DS, Bondeson DP, Ritman EL, Thompson JR, Dow JAT, Romero MF. In vivo Drosophilia genetic model for calcium oxalate nephrolithiasis. Am J Physiol Renal Physiol 2012; 303:F1555-62. [PMID: 22993075 DOI: 10.1152/ajprenal.00074.2012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nephrolithiasis is a major public health problem with a complex and varied etiology. Most stones are composed of calcium oxalate (CaOx), with dietary excess a risk factor. Because of complexity of mammalian system, the details of stone formation remain to be understood. Here we have developed a nephrolithiasis model using the genetic model Drosophila melanogaster, which has a simple, transparent kidney tubule. Drosophilia reliably develops CaOx stones upon dietary oxalate supplementation, and the nucleation and growth of microliths can be viewed in real time. The Slc26 anion transporter dPrestin (Slc26a5/6) is strongly expressed in Drosophilia kidney, and biophysical analysis shows that it is a potent oxalate transporter. When dPrestin is knocked down by RNAi in fly kidney, formation of microliths is reduced, identifying dPrestin as a key player in oxalate excretion. CaOx stone formation is an ancient conserved process across >400 My of divergent evolution (fly and human), and from this study we can conclude that the fly is a good genetic model of nephrolithiasis.
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Affiliation(s)
- Taku Hirata
- Dept. Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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21
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Garcia-Perez I, Villaseñor A, Wijeyesekera A, Posma JM, Jiang Z, Stamler J, Aronson P, Unwin R, Barbas C, Elliott P, Nicholson J, Holmes E. Urinary metabolic phenotyping the slc26a6 (chloride-oxalate exchanger) null mouse model. J Proteome Res 2012; 11:4425-35. [PMID: 22594923 DOI: 10.1021/pr2012544] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The prevalence of renal stone disease is increasing, although it remains higher in men than in women when matched for age. While still somewhat controversial, several studies have reported an association between renal stone disease and hypertension, but this may be confounded by a shared link with obesity. However, independent of obesity, hyperoxaluria has been shown to be associated with hypertension in stone-formers, and the most common type of renal stone is composed of calcium oxalate. The chloride-oxalate exchanger slc26a6 (also known as CFEX or PAT-1), located in the renal proximal tubule, was originally thought to have an important role in sodium homeostasis and thereby blood pressure control, but it has recently been shown to have a key function in oxalate balance by mediating oxalate secretion in the gut. We have applied two orthogonal analytical platforms (NMR spectroscopy and capillary electrophoresis with UV detection) in parallel to characterize the urinary metabolic signatures related to the loss of the renal chloride-oxalate exchanger in slc26a6 null mice. Clear metabolic differentiation between the urinary profiles of the slc26a6 null and the wild type mice were observed using both methods, with the combination of NMR and CE-UV providing extensive coverage of the urinary metabolome. Key discriminating metabolites included oxalate, m-hydroxyphenylpropionylsulfate (m-HPPS), trimethylamine-N-oxide, glycolate and scyllo-inositol (higher in slc26a6 null mice) and hippurate, taurine, trimethylamine, and citrate (lower in slc26a6 null mice). In addition to the reduced efficiency of anion transport, several of these metabolites (hippurate, m-HPPS, methylamines) reflect alteration in gut microbial cometabolic activities. Gender-related metabotypes were also observed in both wild type and slc26a6 null groups. Urinary metabolites that showed a sex-specific pattern included trimethylamine, trimethylamine-N-oxide, citrate, spermidine, guanidinoacetate, and 2-oxoisocaproate. The gender-dependent metabolic expression of the consequences of slc26a6 deletion might have relevance to the difference in prevalence of renal stone formation in men and women. The different composition of microbial metabolites in the slc26a6 null mice is consistent with the fact that the slc26a6 transporter is found in a range of tissues, including the kidney and intestine, and provides further evidence for the "long reach" of the microbiota in physiological and pathological processes.
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Affiliation(s)
- Isabel Garcia-Perez
- Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, SW7 2AZ London, UK
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22
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Abstract
Hyperoxaluria leads to urinary calcium oxalate (CaOx) supersaturation, resulting in the formation and retention of CaOx crystals in renal tissue. CaOx crystals may contribute to the formation of diffuse renal calcifications (nephrocalcinosis) or stones (nephrolithiasis). When the innate renal defense mechanisms are suppressed, injury and progressive inflammation caused by these CaOx crystals, together with secondary complications such as tubular obstruction, may lead to decreased renal function and in severe cases to end-stage renal failure. For decades, research on nephrocalcinosis and nephrolithiasis mainly focused on both the physicochemistry of crystal formation and the cell biology of crystal retention. Although both have been characterized quite well, the mechanisms involved in establishing urinary supersaturation in vivo are insufficiently understood, particularly with respect to oxalate. Therefore, current therapeutic strategies often fail in their compliance or effectiveness, and CaOx stone recurrence is still common. As the etiology of hyperoxaluria is diverse, a good understanding of how oxalate is absorbed and transported throughout the body, together with a better insight in the regulatory mechanisms, is crucial in the setting of future treatment strategies of this disorder. In this review, the currently known mechanisms of oxalate handling in relevant organs will be discussed in relation to the different etiologies of hyperoxaluria. Furthermore, future directions in the treatment of hyperoxaluria will be covered.
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23
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Rendina D, De Filippo G, Zampa G, Muscariello R, Mossetti G, Strazzullo P. Characteristic clinical and biochemical profile of recurrent calcium-oxalate nephrolithiasis in patients with metabolic syndrome. Nephrol Dial Transplant 2010; 26:2256-63. [PMID: 21051502 DOI: 10.1093/ndt/gfq664] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Metabolic syndrome is a risk factor for nephrolithiasis. This study was performed to evaluate the clinical and biochemical profile of calcium-oxalate nephrolithiasis in stone formers with metabolic syndrome. METHODS A total of 526 recurrent stone formers, 184 of them with metabolic syndrome, and 214 controls were examined on a free diet and after a sodium-restricted diet (sodium intake < 100 mmol/24 h). RESULTS On free diet, stone formers with metabolic syndrome showed higher sodium excretion [mean (95% confidence interval), 196 (176-218) vs 160 (150-168) mmol/24 h; P < 0.01] and lower citrate excretion [2.23 (1.99-2.58) vs 2.84 (2.51-3.17) mmol/24 h; P < 0.01] compared to controls, whereas stone formers without metabolic syndrome showed higher calcium and oxalate excretion [5.43 (5.01-5.82) vs 3.58 (2.84-4.19) and 0.34 (0.32-0.36) vs 0.26 (0.20-0.31)m mmol/24 h for calcium and oxalate, respectively; P < 0.01] and lower citrate excretion [2.18 (1.98-2.38) vs 2.84 (2.51-3.17) mmol/24 h; P < 0.01] compared to controls. The ion activity product of urinary calcium-oxalate salts was similar between stone formers with and without metabolic syndrome [1.41 (1.31-1.59) vs 1.40 (1.35-1.45); P > 0.05]. After the test diet, this index was lower in diet-compliant stone formers with metabolic syndrome compared to diet-compliant stone formers without metabolic syndrome [1.15 (1.10-1.21) vs 1.39 (1.31-1.45); P < 0.01]. CONCLUSIONS The biochemical profiles and responses to the sodium-restricted diet were significantly different between stone formers with metabolic syndrome and those without. Dietary habits play a central role in the pathogenesis of nephrolithiasis in stone formers with metabolic syndrome.
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Affiliation(s)
- Domenico Rendina
- Departament of Radiology, Hospital Universitario Insular de Gran Canaria, Spain.
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24
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Christov M, Alper SL. Tubular transport: core curriculum 2010. Am J Kidney Dis 2010; 56:1202-17. [PMID: 21035933 DOI: 10.1053/j.ajkd.2010.09.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 09/14/2010] [Indexed: 12/31/2022]
Affiliation(s)
- Marta Christov
- Renal Division, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.
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25
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Chapman JM, Karniski LP. Protein localization of SLC26A2 (DTDST) in rat kidney. Histochem Cell Biol 2010; 133:541-7. [DOI: 10.1007/s00418-010-0694-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2010] [Indexed: 11/24/2022]
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26
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Chang MH, Plata C, Sindic A, Ranatunga WK, Chen AP, Zandi-Nejad K, Chan KW, Thompson J, Mount DB, Romero MF. Slc26a9 is inhibited by the R-region of the cystic fibrosis transmembrane conductance regulator via the STAS domain. J Biol Chem 2009; 284:28306-28318. [PMID: 19643730 DOI: 10.1074/jbc.m109.001669] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SLC26 proteins function as anion exchangers, channels, and sensors. Previous cellular studies have shown that Slc26a3 and Slc26a6 interact with the R-region of the cystic fibrosis transmembrane conductance regulator (CFTR), (R)CFTR, via the Slc26-STAS (sulfate transporter anti-sigma) domain, resulting in mutual transport activation. We recently showed that Slc26a9 has both nCl(-)-HCO(3)(-) exchanger and Cl(-) channel function. In this study, we show that the purified STAS domain of Slc26a9 (a9STAS) binds purified (R)CFTR. When Slc26a9 and (R)CFTR fragments are co-expressed in Xenopus oocytes, both Slc26a9-mediated nCl(-)-HCO(3)(-) exchange and Cl(-) currents are almost fully inhibited. Deletion of the Slc26a9 STAS domain (a9-DeltaSTAS) virtually eliminated the Cl(-) currents with only a modest affect on nCl(-)-HCO(3)(-) exchange activity. Co-expression of a9-DeltaSTAS and the (R)CFTR fragment did not alter the residual a9-DeltaSTAS function. Replacing the Slc26a9 STAS domain with the Slc26a6 STAS domain (a6-a9-a6) does not change Slc26a9 function and is no longer inhibited by (R)CFTR. These data indicate that the Slc26a9-STAS domain, like other Slc26-STAS domains, binds CFTR in the R-region. However, unlike previously reported data, this binding interaction inhibits Slc26a9 ion transport activity. These results imply that Slc26-STAS domains may all interact with (R)CFTR but that the physiological outcome is specific to differing Slc26 proteins, allowing for dynamic and acute fine tuning of ion transport for various epithelia.
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Affiliation(s)
- Min-Hwang Chang
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106; Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Consuelo Plata
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106; Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México City 14000, Mexico
| | - Aleksandra Sindic
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106; Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Wasantha K Ranatunga
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - An-Ping Chen
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Kambiz Zandi-Nejad
- Renal Division, Brigham and Women's Hospital, Boston, Massachusetts 02115
| | - Kim W Chan
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
| | - James Thompson
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - David B Mount
- Renal Division, Brigham and Women's Hospital, Boston, Massachusetts 02115; Renal Division, Veterans Affairs Boston Healthcare System, West Roxbury, Massachusetts 02132
| | - Michael F Romero
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106; Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota 55905.
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27
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Brzica H, Breljak D, Krick W, Lovrić M, Burckhardt G, Burckhardt BC, Sabolić I. The liver and kidney expression of sulfate anion transporter sat-1 in rats exhibits male-dominant gender differences. Pflugers Arch 2008; 457:1381-92. [DOI: 10.1007/s00424-008-0611-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 10/21/2008] [Accepted: 10/25/2008] [Indexed: 11/28/2022]
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28
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Reference values of plasma oxalate in children and adolescents. Pediatr Nephrol 2008; 23:1787-94. [PMID: 18581146 DOI: 10.1007/s00467-008-0889-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2008] [Revised: 05/06/2008] [Accepted: 05/07/2008] [Indexed: 10/21/2022]
Abstract
Oxalate homeostasis is a derivative of absorption and transportation in the digestive system and renal/intestinal excretion of oxalate. The objective of this cross-sectional study was to determine normative values of plasma oxalate in relation to age, gender, and body size. A group of 1,260 healthy Caucasian children and adolescents aged 3 months to 18 years [mean +/- standard deviation (SD) 10.5 +/- 4.3] was studied. Each 1-year group comprised 70 subjects. Oxalate levels were assessed in blood plasma samples obtained from fasted individuals using the precipitation-enzymatic method with oxalate oxidase. Median oxalate levels in healthy infants was 3.20 micromol/L (5th-95th percentiles: 1.56-5.58) and was higher compared with older children [2.50 micromol/L (5th-95th percentiles: 0.95-5.74); p < 0.01]. No differences were found in plasma oxalate levels between boys and girls. There were no associations between plasma oxalate levels and anthropometric traits. In the healthy population aged 1-18 years, plasma oxalate concentration is independent of age, gender, and body size. Infants demonstrate higher plasma oxalate levels compared with older children, which suggests possible immature mechanisms of renal excretion. This study appears to be the first extensive report providing normative data for plasma oxalate in children and adolescents.
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29
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Abstract
The mammalian intestine has an important role in the dynamics of oxalate exchange and thereby is significant in the etiology of calcium oxalate nephrolithiasis. Here we review some of the phenomenologic observations that have led to the conclusion that anion exchangers (antiporters) are important mediators of secondarily active, net oxalate transport along the intestine (both absorptive and secretory). Understanding the mechanisms of transepithelial oxalate transport has been advanced radically in recent years by the identification of the solute-linked carrier (SLC)26 family of anion transporters, which has facilitated the identification of specific proteins mediating individual apical or basolateral oxalate transport pathways. Moreover, identification of specific exchangers has underscored their relative importance to oxalate homeostasis as revealed by using knockout mouse models and has facilitated studies of oxalate transport regulation in heterologous expression systems. Finally, the significance of oxalate degrading bacteria to oxalate homeostasis is considered from basic and applied perspectives.
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