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Carty JS, Watts JA, Arroyo JP. Vasopressin, protein metabolism, and water conservation. Curr Opin Nephrol Hypertens 2024; 33:512-517. [PMID: 38934092 PMCID: PMC11290986 DOI: 10.1097/mnh.0000000000001012] [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] [Indexed: 06/28/2024]
Abstract
PURPOSE OF REVIEW Highlight the mechanisms through which vasopressin and hypertonic stress regulate protein metabolism. RECENT FINDINGS Mammals have an 'aestivation-like' response in which hypertonic stress increases muscle catabolism and urea productionVasopressin can directly regulate ureagenesis in the liver and the kidneyIn humans chronic hypertonic stress is associated with premature aging, diabetes, cardiovascular disease, and premature mortality. SUMMARY There is an evolutionarily conserved 'aestivation-like' response in humans in which hypertonic stress results in activation of the vasopressin system, muscle catabolism, and ureagenesis in order to promote water conservation.
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Affiliation(s)
- Joshua S Carty
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jason A Watts
- Epigenetics and Stem Cell Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
| | - Juan Pablo Arroyo
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
- Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center, Nashville, Tennessee
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2
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Li N, Zhang H, Wang S, Xu Y, Ying Y, Li J, Li X, Li M, Yang B. Urea transporter UT-A1 as a novel drug target for hyponatremia. FASEB J 2024; 38:e23760. [PMID: 38924449 DOI: 10.1096/fj.202400555rr] [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: 03/11/2024] [Revised: 06/06/2024] [Accepted: 06/13/2024] [Indexed: 06/28/2024]
Abstract
Hyponatremia is the most common disorder of electrolyte imbalances. It is necessary to develop new type of diuretics to treat hyponatremia without losing electrolytes. Urea transporters (UT) play an important role in the urine concentrating process and have been proved as a novel diuretic target. In this study, rat and mouse syndromes of inappropriate antidiuretic hormone secretion (SIADH) models were constructed and analyzed to determine if UTs are a promising drug target for treating hyponatremia. Experimental results showed that 100 mg/kg UT inhibitor 25a significantly increased serum osmolality (from 249.83 ± 5.95 to 294.33 ± 3.90 mOsm/kg) and serum sodium (from 114 ± 2.07 to 136.67 ± 3.82 mmol/L) respectively in hyponatremia rats by diuresis. Serum chemical examination showed that 25a neither caused another electrolyte imbalance nor influenced the lipid metabolism. Using UT-A1 and UT-B knockout mouse SIADH model, it was found that serum osmolality and serum sodium were lowered much less in UT-A1 knockout mice than in UT-B knockout mice, which suggest UT-A1 is a better therapeutic target than UT-B to treat hyponatremia. This study provides a proof of concept that UT-A1 is a diuretic target for SIADH-induced hyponatremia and UT-A1 inhibitors might be developed into new diuretics to treat hyponatremia.
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Affiliation(s)
- Nannan Li
- State Key Laboratory of Vascular Homeostasis and Remodeling, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Hang Zhang
- State Key Laboratory of Vascular Homeostasis and Remodeling, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Shuyuan Wang
- State Key Laboratory of Vascular Homeostasis and Remodeling, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Yue Xu
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
| | - Yi Ying
- State Key Laboratory of Vascular Homeostasis and Remodeling, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Jing Li
- The State Key Laboratory of Anti-Infective Drug Development, Sunshine Lake Pharma Co., Ltd., Dongguan, China
| | - Xiaowei Li
- State Key Laboratory of Vascular Homeostasis and Remodeling, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Min Li
- State Key Laboratory of Vascular Homeostasis and Remodeling, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Baoxue Yang
- State Key Laboratory of Vascular Homeostasis and Remodeling, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
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Raimundo JRS, da Costa Aguiar Alves B, Encinas JFA, Siqueira AM, de Gois KC, Perez MM, Petri G, Dos Santos JFR, Fonseca FLA, da Veiga GL. Expression of TNFR1, VEGFA, CD147 and MCT1 as early biomarkers of diabetes complications and the impact of aging on this profile. Sci Rep 2023; 13:17927. [PMID: 37863950 PMCID: PMC10589356 DOI: 10.1038/s41598-023-41061-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/21/2023] [Indexed: 10/22/2023] Open
Abstract
Hyperglycemia leads to microvascular lesions in various tissues. In diabetic nephropathy-DN, alterations in usual markers reflect an already installed disease. The study of new biomarkers for the early detection of diabetic complications can bring new prevention perspectives. Rats were divided into diabetic adult-DMA-or elderly-DME and control sham adult-CSA-or control sham elderly-CSE. Blood and urine samples were collected for biochemical analysis. Bulbar region, cardiac, hepatic and renal tissues were collected for target gene expression studies. As result, DMA showed decreased TNFR1, MCT1 and CD147 expression in the bulbar region, TNFR1 in the heart, VEGFA and CD147 in the kidney and TNFR1 in blood. Positive correlations were found between TNFR1 and MCT1 in the bulbar region and HbA1c and plasma creatinine, respectively. DME showed positive correlation in the bulbar region between TNFR1 and glycemia, in addition to negative correlations between CD147 in the heart versus glycemia and urea. We concluded that the initial hyperglycemic stimulus already promotes changes in the expression of genes involved in the inflammatory and metabolic pathways, and aging alters this profile. These changes prior to the onset of diseases such as DN, show that they have potential for early biomarkers studies.
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Affiliation(s)
- Joyce Regina Santos Raimundo
- Laboratório de Análises Clínicas do Centro Universitário-Faculdade de Medicina do ABC (FMABC), Avenida Lauro Gomes, 2000, Santo André, SP, 09060-650, Brazil.
| | - Beatriz da Costa Aguiar Alves
- Laboratório de Análises Clínicas do Centro Universitário-Faculdade de Medicina do ABC (FMABC), Avenida Lauro Gomes, 2000, Santo André, SP, 09060-650, Brazil
| | - Jéssica Freitas Araujo Encinas
- Laboratório de Análises Clínicas do Centro Universitário-Faculdade de Medicina do ABC (FMABC), Avenida Lauro Gomes, 2000, Santo André, SP, 09060-650, Brazil
| | - Andressa Moreira Siqueira
- Laboratório de Análises Clínicas do Centro Universitário-Faculdade de Medicina do ABC (FMABC), Avenida Lauro Gomes, 2000, Santo André, SP, 09060-650, Brazil
| | - Katharyna Cardoso de Gois
- Laboratório de Análises Clínicas do Centro Universitário-Faculdade de Medicina do ABC (FMABC), Avenida Lauro Gomes, 2000, Santo André, SP, 09060-650, Brazil
| | - Matheus Moreira Perez
- Laboratório de Análises Clínicas do Centro Universitário-Faculdade de Medicina do ABC (FMABC), Avenida Lauro Gomes, 2000, Santo André, SP, 09060-650, Brazil
| | - Giuliana Petri
- Vivarium and Animal Experimentation Laboratory-Faculdade de Medicina Do ABC (FMABC), Avenida Lauro Gomes, 2000, Santo André, SP, 09060-650, Brazil
| | - José Francisco Ramos Dos Santos
- Vivarium and Animal Experimentation Laboratory-Faculdade de Medicina Do ABC (FMABC), Avenida Lauro Gomes, 2000, Santo André, SP, 09060-650, Brazil
| | - Fernando Luiz Affonso Fonseca
- Laboratório de Análises Clínicas do Centro Universitário-Faculdade de Medicina do ABC (FMABC), Avenida Lauro Gomes, 2000, Santo André, SP, 09060-650, Brazil
- Departamento de Ciências Farmacêuticas da Universidade Federal de São Paulo/UNIFESP, Campus Diadema, Rua Prof. Artur Riedel, 275, Diadema, SP, 09972-270, Brazil
| | - Glaucia Luciano da Veiga
- Laboratório de Análises Clínicas do Centro Universitário-Faculdade de Medicina do ABC (FMABC), Avenida Lauro Gomes, 2000, Santo André, SP, 09060-650, Brazil
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Prahl MC, Müller CBM, Wimmers K, Kuhla B. Mammary gland, kidney and rumen urea and uric acid transporters of dairy cows differing in milk urea concentration. Sci Rep 2023; 13:17231. [PMID: 37821556 PMCID: PMC10567808 DOI: 10.1038/s41598-023-44416-9] [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: 05/09/2023] [Accepted: 10/08/2023] [Indexed: 10/13/2023] Open
Abstract
The milk urea concentration (MUC) serves as indicator of urinary nitrogen emissions, but at comparable crude protein (CP) intake, cows with high (HMU) and low (LMU) MUC excrete equal urea amounts. We hypothesized that urea and uric acid transporters and sizes of the kidney, mammary gland, and rumen account for these phenotypes. Eighteen HMU and 18 LMU Holstein dairy cows fed a low (LP) and normal (NP) CP diet were studied. Milk, plasma and urinary urea concentrations were greater with NP feeding, while plasma and urinary urea concentrations were comparable between phenotypes. Milk and plasma uric acid concentrations were higher with LP feeding but not affected by phenotype. The milk-urine uric acid ratio was greater in HMU cows. The mRNA expressions of the ruminal urea transporter SLC14A1 and AQP10, the mammary gland and rumen AQP3, and the mammary gland uric acid transporter ABCG2 were not affected by group or diet. Renal AQP10, but not AQP3, AQP7, and SLC14A2 expressions, and the kidney weights were lower in HMU cows. These data indicate that renal size and AQP10 limit the urea transfer from blood to urine, and that MUC determines if uric acid is more released with milk or urine.
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Affiliation(s)
- Marie C Prahl
- Research Institute for Farm Animal Biology (FBN), Institute of Nutritional Physiology 'Oskar Kellner', Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Carolin B M Müller
- Research Institute for Farm Animal Biology (FBN), Institute of Nutritional Physiology 'Oskar Kellner', Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Klaus Wimmers
- Research Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Björn Kuhla
- Research Institute for Farm Animal Biology (FBN), Institute of Nutritional Physiology 'Oskar Kellner', Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany.
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Chi G, Dietz L, Tang H, Snee M, Scacioc A, Wang D, Mckinley G, Mukhopadhyay SM, Pike AC, Chalk R, Burgess-Brown NA, Timmermans JP, van Putte W, Robinson CV, Dürr KL. Structural characterization of human urea transporters UT-A and UT-B and their inhibition. SCIENCE ADVANCES 2023; 9:eadg8229. [PMID: 37774028 PMCID: PMC10541013 DOI: 10.1126/sciadv.adg8229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 08/30/2023] [Indexed: 10/01/2023]
Abstract
In this study, we present the structures of human urea transporters UT-A and UT-B to characterize them at molecular level and to detail the mechanism of UT-B inhibition by its selective inhibitor, UTBinh-14. High-resolution structures of both transporters establish the structural basis for the inhibitor's selectivity to UT-B, and the identification of multiple binding sites for the inhibitor will aid with the development of drug lead molecules targeting both transporters. Our study also discovers phospholipids associating with the urea transporters by combining structural observations, native MS, and lipidomics analysis. These insights improve our understanding of urea transporter function at a molecular level and provide a blueprint for a structure-guided design of therapeutics targeting these transporters.
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Affiliation(s)
- Gamma Chi
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Larissa Dietz
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Haiping Tang
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Matthew Snee
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Andreea Scacioc
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Dong Wang
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Gavin Mckinley
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Shubhashish M. M. Mukhopadhyay
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Ashley C. W. Pike
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Rod Chalk
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Nicola A. Burgess-Brown
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Jean-Pierre Timmermans
- Laboratory of Cell Biology and Histology (CBH) at Antwerp Centre for Advanced Microscopy (ACAM), Department of Veterinary Sciences, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Wouter van Putte
- Laboratory of Cell Biology and Histology (CBH) at Antwerp Centre for Advanced Microscopy (ACAM), Department of Veterinary Sciences, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- PUXANO, Ottergemsesteenweg Zuid 713, 9000 Gent, Belgium
| | - Carol V. Robinson
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Katharina L. Dürr
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
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6
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Mufti A, Feriani A, Ouchari W, Mandour YM, Tlili N, Ibrahim MA, Mahmoud MF, Sobeh M. Leonotis ocymifolia (Burm.f.) Iwarsson aerial parts aqueous extract mitigates cisplatin-induced nephrotoxicity via attenuation of inflammation, and DNA damage. Front Pharmacol 2023; 14:1221486. [PMID: 37593171 PMCID: PMC10428015 DOI: 10.3389/fphar.2023.1221486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/17/2023] [Indexed: 08/19/2023] Open
Abstract
Herein, we explored the protective effect of Leonotis ocymifolia (Burm.f.) Iwarsson aerial parts extract (LO) against cisplatin (CP)-induced nephrotoxicity in rats and profiled their phytocontents. A total of 31 compounds belonging to organic and phenolic acids and their glycosides as well as flavonoids and their O- and C-glycosides were identified through LC-MS/MS. The DPPH and FRAP assays revealed that the extract had powerful antioxidant properties. The in vivo results demonstrated that administering LO extract for 30 days (40 and 80 mg/kg b. w.) significantly improved the altered renal injury markers via reducing creatinine (high dose only) and uric acid levels compared to the Cp-group. The deleterious action of cisplatin on renal oxidative stress markers (GSH, MDA, SOD, and CAT) were also mitigated by LO-pretreatment. The reduction of the inflammatory marker (IL-6), and inhibition of DNA fragmentation, highlighted the prophylactic action of LO in kidney tissue. Molecular docking followed by a 100 ns molecular dynamic simulation analyses revealed that, amongst the 31 identified compounds in LO, chlorogenic and caffeoylmalic acids had the most stable binding to IL-6. The nephroprotective effects were further confirmed by histopathological observations, which showed improvement in ultrastructural changes induced by cisplatin. The observed findings reinforce the conclusion that L. ocymifolia extract exerts nephroprotective properties, which could be related to its antioxidant and anti-inflammatory activities. Further studies are required to determine the therapeutic doses and the proper administration time.
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Affiliation(s)
- Afoua Mufti
- Laboratory of Biotechnology and Biomonitoring of the Environment and Oasis Ecosystems, Faculty of Sciences of Gafsa, University of Gafsa, Gafsa, Tunisia
| | - Anouar Feriani
- Laboratory of Biotechnology and Biomonitoring of the Environment and Oasis Ecosystems, Faculty of Sciences of Gafsa, University of Gafsa, Gafsa, Tunisia
| | - Wafae Ouchari
- AgroBioSciences Program, College for Sustainable Agriculture and Environmental Science, Mohammed VI Polytechnic University, Ben Guerir, Morocco
| | - Yasmine M. Mandour
- School of Life and Medical Sciences, University of Hertfordshire Hosted By Global Academic Foundation, Cairo, Egypt
| | - Nizar Tlili
- Institut Supérieur des Sciences et Technologies de L’Environnement, Université de Carthage, Carthage, Tunisia
| | | | - Mona F. Mahmoud
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Mansour Sobeh
- AgroBioSciences Program, College for Sustainable Agriculture and Environmental Science, Mohammed VI Polytechnic University, Ben Guerir, Morocco
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Xu Y, Wang S, Ma W, Li J, Lu Y, Abulizi A, Sun J, Yang B. An HPLC-MS/MS Method for Pharmacokinetic Study of Y-99: A Novel Diuretic Agent Targeting Urea Transporters. J Chromatogr Sci 2023; 61:552-558. [PMID: 36369644 DOI: 10.1093/chromsci/bmac089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 04/05/2022] [Accepted: 10/12/2022] [Indexed: 07/20/2023]
Abstract
Y-99, a promising first-in-class diuretic, is a novel urea transporter inhibitor with oral diuretic activity. However, little is known about the pharmacokinetic profiles of Y-99 in experimental animals. In this study, a method of quantitative determination of Y-99 in rat plasma based on high-performance liquid chromatography-tandem mass spectrometry was developed and validated in selectivity, linearity, recovery and matrix effect, accuracy and precision, stability, carry-over and dilution integrity. Chromatographic separation was conducted on an ACQUITY BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with gradient elution at a 0.3 mL/min flow rate after protein precipitation. Mass spectrometry was performed by a positive electrospray ionization mass spectrometer in multiple reaction monitoring mode. The method showed standard-compliant linearity (1-1,000 ng/mL, r = 0.9991). The intra-day and inter-day accuracy (relative error < 11.2%) and precision (coefficient of variation <8.4%) were within acceptable criteria. The recovery and matrix effects were 97.3-110.7% and 103.7-107.5%, respectively. The stability, dilution integrity and carry-over of the method were also within the acceptable criteria. Pharmacokinetic profiles of Y-99 in rats were first investigated using this method, which was vital for developing novel diuretics without electrolyte imbalance targeting urea transporters.
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Affiliation(s)
- Yue Xu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Shuyuan Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Wen Ma
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Jun Li
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Yingyuan Lu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Abudumijiti Abulizi
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Jianguo Sun
- Key Lab of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Baoxue Yang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing 100191, China
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8
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Zhang L, Chen Y, Zhou Z, Wang Z, Fu L, Zhang L, Xu C, Loor JJ, Wang G, Zhang T, Dong X. Vitamin C injection improves antioxidant stress capacity through regulating blood metabolism in post-transit yak. Sci Rep 2023; 13:10233. [PMID: 37353533 PMCID: PMC10290073 DOI: 10.1038/s41598-023-36779-w] [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: 01/03/2023] [Accepted: 06/09/2023] [Indexed: 06/25/2023] Open
Abstract
Transportation stress is one of the most serious issues in the management of yak. Previous studies have demonstrated that transport stress is caused by a pro-oxidant state in the animal resulting from an imbalance between pro-oxidant and antioxidant status. In this context, vitamin C has the ability to regulate reactive oxygen species (ROS) synthesis and alleviate oxidative stress. Although this effect of vitamin C is useful in pigs, goats and cattle, the effect of vitamin C on the mitigation of transport stress in yaks is still unclear. The purpose of this study was to better assess the metabolic changes induced by the action of vitamin C in yaks under transportation stress, and whether these changes can influence antioxidant status. After the yaks arrived at the farm, control or baseline blood samples were collected immediately through the jugular vein (VC_CON). Then, 100 mg/kg VC was injected intramuscularly, and blood samples were collected on the 10th day before feeding in the morning (VC). Relative to the control group, the VC injection group had higher levels of VC. Compared with VC_CON, VC injection significantly (P < 0.05) decreased the blood concentrations of ALT, AST, T-Bil, D-Bil, IDBIL, UREA, CRP and LDH. However, VC injection led to greater (P < 0.05) AST/ALT and CREA-S relative to VC_CON. There was no difference (P > 0.05) in GGT, ALP, TBA, TP, ALBII, GLO, A/G, TC, TG, HDL-C, LDL-C, GLU and L-lactate between VC_CON and VC. The injection of VC led to greater (P < 0.05) concentration of MDA, but did not alter (P > 0.05) the serum concentrations of LPO and ROS. The injection of VC led to greater (P < 0.05) serum concentrations of POD, CAT and GSH-PX. In contrast, lower (P < 0.05) serum concentrations of SOD, POD and TPX were observed in VC relative to VC_CON. No difference (P > 0.05) in GSH, GSH-ST and GR was observed between VC_CON and VC. Compared with the control group, metabolomics using liquid chromatography tandem-mass spectrometry identified 156 differential metabolites with P < 0.05 and a variable importance in projection (VIP) score > 1.5 in the VC injection group. The injection of VC resulted in significant changes to the intracellular amino acid metabolism of glutathione, glutamate, cysteine, methionine, glycine, phenylalanine, tyrosine, tryptophan, alanine and aspartate. Overall, our study indicated that VC injections were able to modulate antioxidant levels by affecting metabolism to resist oxidative stress generated during transport.
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Affiliation(s)
- Li Zhang
- Chongqing Academy of Animal Sciences, Rongchang, 402460, China
| | - Yi Chen
- Chongqing Engineering Laboratory of Nano/Micro Biomedical Detection; Chongqing Key Laboratory of Nano/Micro Composite Material and Device, College of Metallurgy and Materials Engineering, Chongqing University of Science and Technology, Chongqing, 401331, China
| | - Ziyao Zhou
- Chongqing Academy of Animal Sciences, Rongchang, 402460, China
- The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Zhiyu Wang
- The Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Lin Fu
- Chongqing Academy of Animal Sciences, Rongchang, 402460, China
| | - Lijun Zhang
- Tibet Leowuqi Animal Husbandry Station, Changdu Tibet, 855600, China
| | - Changhui Xu
- Tibet Leowuqi Animal Husbandry Station, Changdu Tibet, 855600, China
| | - Juan J Loor
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, 61801, USA
| | - Gaofu Wang
- Chongqing Academy of Animal Sciences, Rongchang, 402460, China
| | - Tao Zhang
- Chongqing Engineering Laboratory of Nano/Micro Biomedical Detection; Chongqing Key Laboratory of Nano/Micro Composite Material and Device, College of Metallurgy and Materials Engineering, Chongqing University of Science and Technology, Chongqing, 401331, China.
| | - Xianwen Dong
- Chongqing Academy of Animal Sciences, Rongchang, 402460, China.
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9
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Xu Y, Zhang H, Li N, Ma W, Wang S, Sun J, Yang B. Preclinical Pharmacokinetic Studies of a Novel Diuretic Inhibiting Urea Transporters. Molecules 2022; 27:2451. [PMID: 35458649 PMCID: PMC9027532 DOI: 10.3390/molecules27082451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 04/02/2022] [Accepted: 04/07/2022] [Indexed: 11/16/2022] Open
Abstract
Urea transporter (UT) inhibitors are a class of promising novel diuretics that do not cause the imbalance of Na+, K+, Cl-, and other electrolytes. In our previous studies, 25a, a promising diuretic candidate inhibiting UT, was discovered and showed potent diuretic activities in rodents. Here, a sensitive liquid chromatography-tandem mass spectrometry method for the quantitation of 25a in rat plasma, urine, feces, bile, and tissue homogenates was developed and validated to support the preclinical pharmacokinetic studies. The tissue distribution, excretion, and plasma protein binding were investigated in rats. After a single oral dose of 25a at 25, 50, and 100 mg/kg, the drug exposure increased linearly with the dose. The drug accumulation was observed after multiple oral doses compared to a single dose. In the distribution study, 25a exhibited a wide distribution to tissues with high blood perfusion, such as kidney, heart, lung, and spleen, and the lowest distribution in the brain and testis. The accumulative excretion rate of 25a was 0.14%, 3.16%, and 0.018% in urine, feces, and bile, respectively. The plasma protein binding of 25a was approximately 60% in rats and 40% in humans. This is the first study on the preclinical pharmacokinetic profiles of 25a.
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Affiliation(s)
- Yue Xu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (Y.X.); (H.Z.); (N.L.); (S.W.)
| | - Hang Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (Y.X.); (H.Z.); (N.L.); (S.W.)
| | - Nannan Li
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (Y.X.); (H.Z.); (N.L.); (S.W.)
| | - Wen Ma
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China;
| | - Shuyuan Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (Y.X.); (H.Z.); (N.L.); (S.W.)
| | - Jianguo Sun
- Key Lab of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, 24 Tongjiaxiang Street, Nanjing 210009, China;
| | - Baoxue Yang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing 100191, China; (Y.X.); (H.Z.); (N.L.); (S.W.)
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10
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Kuriyama S, Tanaka G, Takagane K, Itoh G, Tanaka M. Pigment Epithelium Derived Factor Is Involved in the Late Phase of Osteosarcoma Metastasis by Increasing Extravasation and Cell-Cell Adhesion. Front Oncol 2022; 12:818182. [PMID: 35174090 PMCID: PMC8842676 DOI: 10.3389/fonc.2022.818182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/07/2022] [Indexed: 11/13/2022] Open
Abstract
Organ tropism of metastatic cells is not well understood. To determine the key factors involved in the selection of a specific organ upon metastasis, we established metastatic cell lines and analyzed their homing to specific tissues. Toward this, 143B osteosarcoma cells were injected intracardially until the kidney-metastasizing sub-cell line Bkid was established, which significantly differed from the parental 143B cells. The candidate genes responsible for kidney metastasis were validated, and SerpinF1/Pigment epithelium derived factor (PEDF) was identified as the primary target. Bkid cells with PEDF knockdown injected intracardially did not metastasize to the kidneys. In contrast, PEDF overexpressing 143B cells injected into femur metastasized to the lungs and kidneys. PEDF triggered mesenchymal-to-epithelial transition (MET) in vitro as well as in vivo. Based on these results, we hypothesized that the MET might be a potential barrier to extravasation. PEDF overexpression in various osteosarcoma cell lines increased their extravasation to the kidneys and lungs. Moreover, when cultured close to the renal endothelial cell line TKD2, Bkid cells disturbed the TKD2 layer and hindered wound healing via the PEDF-laminin receptor (lamR) axis. Furthermore, novel interactions were observed among PEDF, lamR, lysyl oxidase-like 1 (Loxl1), and SNAI3 (Snail-like transcription factor) during endothelial-to-mesenchymal transition (EndoMT). Collectively, our results show that PEDF induces cancer cell extravasation by increasing the permeability of kidney and lung vasculature acting via lamR and its downstream genes. We also speculate that PEDF promotes extravasation via inhibiting EndoMT, and this warrants investigation in future studies.
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Affiliation(s)
- Sei Kuriyama
- Department of Molecular Medicine and Biochemistry, Graduate School and Faculty of Medicine, Akita University, Akita City, Japan
| | - Gentaro Tanaka
- Department of Molecular Medicine and Biochemistry, Graduate School and Faculty of Medicine, Akita University, Akita City, Japan.,Department of Lifescience, Faculty and Graduate School of Engineering and Resource Science, Akita University, Akita City, Japan
| | - Kurara Takagane
- Department of Molecular Medicine and Biochemistry, Graduate School and Faculty of Medicine, Akita University, Akita City, Japan
| | - Go Itoh
- Department of Molecular Medicine and Biochemistry, Graduate School and Faculty of Medicine, Akita University, Akita City, Japan
| | - Masamitsu Tanaka
- Department of Molecular Medicine and Biochemistry, Graduate School and Faculty of Medicine, Akita University, Akita City, Japan
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11
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Marcoux AA, Tremblay LE, Slimani S, Fiola MJ, Mac-Way F, Haydock L, Garneau AP, Isenring P. Anatomophysiology of the Henle's Loop: Emphasis on the Thick Ascending Limb. Compr Physiol 2021; 12:3119-3139. [PMID: 34964111 DOI: 10.1002/cphy.c210021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The loop of Henle plays a variety of important physiological roles through the concerted actions of ion transport systems in both its apical and basolateral membranes. It is involved most notably in extracellular fluid volume and blood pressure regulation as well as Ca2+ , Mg2+ , and acid-base homeostasis because of its ability to reclaim a large fraction of the ultrafiltered solute load. This nephron segment is also involved in urinary concentration by energizing several of the steps that are required to generate a gradient of increasing osmolality from cortex to medulla. Another important role of the loop of Henle is to sustain a process known as tubuloglomerular feedback through the presence of specialized renal tubular cells that lie next to the juxtaglomerular arterioles. This article aims at describing these physiological roles and at discussing a number of the molecular mechanisms involved. It will also report on novel findings and uncertainties regarding the realization of certain processes and on the pathophysiological consequences of perturbed salt handling by the thick ascending limb of the loop of Henle. Since its discovery 150 years ago, the loop of Henle has remained in the spotlight and is now generating further interest because of its role in the renal-sparing effect of SGLT2 inhibitors. © 2022 American Physiological Society. Compr Physiol 12:1-21, 2022.
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Affiliation(s)
- Andrée-Anne Marcoux
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Laurence E Tremblay
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Samira Slimani
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Marie-Jeanne Fiola
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Fabrice Mac-Way
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Ludwig Haydock
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Alexandre P Garneau
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada.,Cardiometabolic Axis, School of Kinesiology and Physical Activity Sciences, University of Montréal, Montréal, QC, Canada
| | - Paul Isenring
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
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12
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Hailemariam S, Zhao S, He Y, Wang J. Urea transport and hydrolysis in the rumen: A review. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2021; 7:989-996. [PMID: 34738029 PMCID: PMC8529027 DOI: 10.1016/j.aninu.2021.07.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 07/02/2021] [Accepted: 07/08/2021] [Indexed: 11/29/2022]
Abstract
Inefficient dietary nitrogen (N) conversion to microbial proteins, and the subsequent use by ruminants, is a major research focus across different fields. Excess bacterial ammonia (NH3) produced due to degradation or hydrolyses of N containing compounds, such as urea, leads to an inefficiency in a host's ability to utilize nitrogen. Urea is a non-protein N containing compound used by ruminants as an ammonia source, obtained from feed and endogenous sources. It is hydrolyzed by ureases from rumen bacteria to produce NH3 which is used for microbial protein synthesis. However, lack of information exists regarding urea hydrolysis in ruminal bacteria, and how urea gets to hydrolysis sites. Therefore, this review describes research on sites of urea hydrolysis, urea transport routes towards these sites, the role and structure of urea transporters in rumen epithelium and bacteria, the composition of ruminal ureolytic bacteria, mechanisms behind urea hydrolysis by bacterial ureases, and factors influencing urea hydrolysis. This review explores the current knowledge on the structure and physiological role of urea transport and ureolytic bacteria, for the regulation of urea hydrolysis and recycling in ruminants. Lastly, underlying mechanisms of urea transportation in rumen bacteria and their physiological importance are currently unknown, and therefore future research should be directed to this subject.
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Affiliation(s)
- Samson Hailemariam
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
- Dilla University, College of Agriculture and Natural Resource, Dilla P. O. Box 419, Ethiopia
| | - Shengguo Zhao
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yue He
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jiaqi Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
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13
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Nandi S, Sanyal S, Amin SA, Kashaw SK, Jha T, Gayen S. Urea transporter and its specific and nonspecific inhibitors: State of the art and pharmacological perspective. Eur J Pharmacol 2021; 911:174508. [PMID: 34536365 DOI: 10.1016/j.ejphar.2021.174508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/10/2021] [Accepted: 09/14/2021] [Indexed: 01/11/2023]
Abstract
Hypertension is a major concern for a wide array of patients. The traditional drugs are commonly referred as 'water pills' and these molecules have been successful in alleviating hypertension. However, this comes at the high expense of precious electrolytes in our body. To dissipate this major adverse effect, the urea transporter inhibitors play especially important roles in maintaining the fluid balance by maintaining the concentration of urea in the inner medullary collecting duct. The purpose of this communication is to provide insights into the structural feature of these target proteins and inhibition of both urea transporter types A (UT-A) and B (UT-B) selectively and non-selectively with a special focus on the UT-A inhibitors as they are the primary target for diuresis. It was observed that a wide class of drugs such as thiourea analogues, 2,7-disubstituted fluorenones can inhibit both the protein non-selectively whereas 8-hydroxyquinoline, aminothiazolone, 1,3,5-triazine, triazolothienopyrimidine, thienoquinoline, arylthiazole, γ-sultambenzosulfonamide and 1,2,4-triazoloquinoxaline classes of compounds inhibit UT-A. The goal of this study is to highlight the important aspects that may be useful to understanding the perspectives of urea transporter inhibitors in rational drug discovery.
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Affiliation(s)
- Sudipta Nandi
- Department of Pharmaceutical Sciences, Dr. Harisingh Gour University, Sagar, MP, India
| | - Saptarshi Sanyal
- School of Pharmaceutical Technology, Adamas University, Kolkata, India; Natural Science Laboratory, Division of Medicinal and Pharmaceutical Chemistry, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, India
| | - Sk Abdul Amin
- Natural Science Laboratory, Division of Medicinal and Pharmaceutical Chemistry, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, India
| | - Sushil Kumar Kashaw
- Department of Pharmaceutical Sciences, Dr. Harisingh Gour University, Sagar, MP, India
| | - Tarun Jha
- Natural Science Laboratory, Division of Medicinal and Pharmaceutical Chemistry, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, India.
| | - Shovanlal Gayen
- Department of Pharmaceutical Sciences, Dr. Harisingh Gour University, Sagar, MP, India; Laboratory of Drug Design and Discovery, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, India.
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14
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Liu S, Wang C, Yang Y, Cai H, Zhang M, Si L, Zhang S, Xu Y, Zhu J, Yu Y. Brain structure and perfusion in relation to serum renal function indexes in healthy young adults. Brain Imaging Behav 2021; 16:1014-1025. [PMID: 34709557 DOI: 10.1007/s11682-021-00565-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2021] [Indexed: 11/30/2022]
Abstract
Prior neuroimaging studies of the relationship between the kidney and the brain have been limited to clinical populations and have largely relied on a single modality. We sought to examine the kidney-brain associations in healthy subjects using a combined analysis of multi-modal imaging data. Structural, diffusion, and perfusion magnetic resonance imaging (MRI) scans were performed to measure cortical thickness, white matter integrity, and cerebral blood flow in 157 healthy young adults. Peripheral venous blood samples were collected to measure serum renal function indexes. Correlation analyses were performed to investigate the relations between brain MRI measures and renal function indexes. Results showed that higher serum uric acid level was associated with increased cortical thickness in the transverse temporal gyrus. We also found that decreased serum creatinine level was linked to lower white matter integrity in the sagittal stratum, anterior corona radiata, superior corona radiata, and external capsule. Furthermore, we observed that increased serum uric acid level was related to hyperperfusion in the opercular and triangular parts of inferior frontal gyrus and supramarginal gyrus, and hypoperfusion in the calcarine sulcus, cuneus and lingual gyrus. More importantly, mediation analysis revealed that the relationship between serum uric acid and working memory performance was mediated by perfusion in the supramarginal gyrus and lingual gyrus. These findings not only may extend current knowledge regarding the relationship between the kidney and the brain, but also may inform real-world clinical practice by identification of potential brain regions vulnerable to renal dysfunction.
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Affiliation(s)
- Siyu Liu
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, No. 218, Jixi Road, Shushan District, Hefei, 230022, China
| | - Chunli Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China
| | - Ying Yang
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, No. 218, Jixi Road, Shushan District, Hefei, 230022, China
| | - Huanhuan Cai
- Medical Imaging Center, The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, 230031, China
| | - Min Zhang
- Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China
| | - Li Si
- Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China
| | - Shujun Zhang
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, No. 218, Jixi Road, Shushan District, Hefei, 230022, China
| | - Yuanhong Xu
- Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China
| | - Jiajia Zhu
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, No. 218, Jixi Road, Shushan District, Hefei, 230022, China.
| | - Yongqiang Yu
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, No. 218, Jixi Road, Shushan District, Hefei, 230022, China.
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15
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Fransson M, Helldén A, Östholm Balkhed Å, Nezirević Dernroth D, Ha M, Haglund M, Milos P, Hanberger H, Kågedal B. Case Report: Subtherapeutic Vancomycin and Meropenem Concentrations due to Augmented Renal Clearance in a Patient With Intracranial Infection Caused by Streptococcus intermedius. Front Pharmacol 2021; 12:728075. [PMID: 34690767 PMCID: PMC8527190 DOI: 10.3389/fphar.2021.728075] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 09/01/2021] [Indexed: 12/24/2022] Open
Abstract
Streptococcus intermedius occasionally causes brain abscesses that can be life-threatening, requiring prompt antibiotic and neurosurgical treatment. The source is often dental, and it may spread to the eye or the brain parenchyma. We report the case of a 34-year-old man with signs of apical periodontitis, endophthalmitis, and multiple brain abscesses caused by Streptococcus intermedius. Initial treatment with meropenem and vancomycin was unsuccessful due to subtherapeutic concentrations, despite recommended dosages. Adequate concentrations could be reached only after increasing the dose of meropenem to 16 g/day and vancomycin to 1.5 g × 4. The patient exhibited high creatinine clearance consistent with augmented renal clearance, although iohexol and cystatin C clearances were normal. Plasma free vancomycin clearance followed that of creatinine. A one-day dose of trimethoprim–sulfamethoxazole led to an increase in serum creatinine and a decrease in both creatinine and urea clearances. These results indicate that increased tubular secretion of the drugs was the cause of suboptimal antibiotic treatment. The patient eventually recovered, but his left eye needed enucleation. Our case illustrates that augmented renal clearance can jeopardize the treatment of serious bacterial infections and that high doses of antibiotics are needed to achieve therapeutic concentrations in such cases. The mechanisms for regulation of kidney tubular transporters of creatinine, urea, vancomycin, and meropenem in critically ill patients are discussed.
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Affiliation(s)
- Marcus Fransson
- Department of Neurosurgery and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Anders Helldén
- Department of Clinical Chemistry and Clinical Pharmacology and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Åse Östholm Balkhed
- Department of Infectious Diseases, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Dženeta Nezirević Dernroth
- Department of Clinical Chemistry and Clinical Pharmacology and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Maria Ha
- Department of Infectious Diseases, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Mats Haglund
- Department of Infectious Diseases, Kalmar County Hospital, Kalmar, Sweden
| | - Peter Milos
- Department of Neurosurgery and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Håkan Hanberger
- Department of Infectious Diseases, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Bertil Kågedal
- Department of Clinical Chemistry and Clinical Pharmacology and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
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16
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Han M, Chen LY. Molecular dynamics simulation of human urea transporter B. MOLECULAR SIMULATION 2021. [DOI: 10.1080/08927022.2021.1941944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Ming Han
- Department of Physics, University of Texas at San Antonio, San Antonio, TX, USA
| | - Liao Y. Chen
- Department of Physics, University of Texas at San Antonio, San Antonio, TX, USA
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17
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Guo Z, Niu X, Fu G, Yang B, Chen G, Sun S. SLC14A1 (UT-B) gene rearrangement in urothelial carcinoma of the bladder: a case report. Diagn Pathol 2020; 15:94. [PMID: 32703295 PMCID: PMC7376696 DOI: 10.1186/s13000-020-01009-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 07/14/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Bladder cancer (BC) is a common and deadly disease. Over the past decade, a number of genetic alterations have been reported in BC. Bladder urothelium expresses abundant urea transporter UT-B encoded by Slc14a1 gene at 18q12.3 locus, which plays an important role in preventing high concentrated urea-caused cell injury. Early genome-wide association studies (GWAS) showed that UT-B gene mutations are genetically linked to the urothelial bladder carcinoma (UBC). In this study, we examined whether Slc14a1 gene has been changed in UBC, which has never been reported. CASE PRESENTATION A 59-year-old male was admitted to a hospital with the complaint of gross hematuria for 6 days. Ultrasonography revealed a size of 2.8 × 1.7 cm mass lesion located on the rear wall and dome of the bladder. In cystoscopic examination, papillary tumoral lesions 3.0-cm in total diameter were seen on the left wall of the bladder and 2 cm to the left ureteric orifice. Transurethral resection of bladder tumor (TURBT) was performed. Histology showed high-grade non-muscle invasive UBC. Immunostaining was negative for Syn, CK7, CK20, Villin, and positive for HER2, BRCA1, GATA3. Using a fluorescence in situ hybridization (FISH), Slc14a1 gene rearrangement was identified by a pair of break-apart DNA probes. CONCLUSIONS We for the first time report a patient diagnosed with urothelial carcinoma accompanied with split Slc14a1 gene abnormality, a crucial gene in bladder.
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Affiliation(s)
- Zhongying Guo
- Department of Pathology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, 223300, China
| | - Xiaobing Niu
- Department of Urology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, 223300, China
| | - Guangbo Fu
- Department of Urology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, 223300, China
| | - Baoxue Yang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Guangping Chen
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
| | - Su'an Sun
- Department of Pathology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, 223300, China.
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18
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Pelletier CC, Croyal M, Ene L, Aguesse A, Billon-Crossouard S, Krempf M, Lemoine S, Guebre-Egziabher F, Juillard L, Soulage CO. Elevation of Trimethylamine-N-Oxide in Chronic Kidney Disease: Contribution of Decreased Glomerular Filtration Rate. Toxins (Basel) 2019; 11:toxins11110635. [PMID: 31683880 PMCID: PMC6891811 DOI: 10.3390/toxins11110635] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/21/2019] [Accepted: 10/30/2019] [Indexed: 12/22/2022] Open
Abstract
Gut microbiota-dependent Trimethylamine-N-oxide (TMAO) has been reported to be strongly linked to renal function and to increased cardiovascular events in the general population and in Chronic Kidney Disease (CKD) patients. Considering the lack of data assessing renal handling of TMAO, we conducted this study to explore renal excretion and mechanisms of accumulation of TMAO during CKD. We prospectively measured glomerular filtration rate (mGFR) with gold standard methods and plasma concentrations of trimethylamine (TMA), TMAO, choline, betaine, and carnitine by LC-MS/MS in 124 controls, CKD, and hemodialysis (HD) patients. Renal clearance of each metabolite was assessed in a sub-group of 32 patients. Plasma TMAO was inversely correlated with mGFR (r2 = 0.388, p < 0.001), confirming elevation of TMAO plasma levels in CKD. TMAO clearances were not significantly different from mGFR, with a mean ± SD TMAO fractional excretion of 105% ± 32%. This suggests a complete renal excretion of TMAO by glomerular filtration with a negligible participation of tubular secretion or reabsorption, during all stages of CKD. Moreover, TMAO was effectively removed within 4 h of hemodiafiltration, showing a higher fractional reduction value than that of urea (84.9% ± 6.5% vs. 79.2% ± 5.7%, p = 0.04). This study reports a strong correlation between plasma TMAO levels and mGFR, in CKD, that can be mainly related to a decrease in TMAO glomerular filtration. Clearance data did not support a significant role for tubular secretion in TMAO renal elimination.
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Affiliation(s)
- Caroline C Pelletier
- Hospices Civils de Lyon, Service de Néphrologie, Dialyse et Hypertension Artérielle, Hôpital E Herriot, F-69003 Lyon, France.
- Université de Lyon, INSERM U1060, CarMeN, INSA de Lyon, Univ Lyon-1, F-69621 Villeurbanne, France.
| | - Mikael Croyal
- NUN, INRA, CHU Nantes, UMR 1280, PhAN, IMAD, CRNH-O, F-44000 Nantes, France.
- CRNH-O Mass Spectrometry Core Facility, F-44000 Nantes, France.
| | - Lavinia Ene
- Hospices Civils de Lyon, Service de Néphrologie, Dialyse et Hypertension Artérielle, Hôpital E Herriot, F-69003 Lyon, France.
| | - Audrey Aguesse
- NUN, INRA, CHU Nantes, UMR 1280, PhAN, IMAD, CRNH-O, F-44000 Nantes, France.
| | | | - Michel Krempf
- NUN, INRA, CHU Nantes, UMR 1280, PhAN, IMAD, CRNH-O, F-44000 Nantes, France.
- CRNH-O Mass Spectrometry Core Facility, F-44000 Nantes, France.
- ELSAN, clinique Bretéché, F-44000 Nantes, France.
| | - Sandrine Lemoine
- Hospices Civils de Lyon, Service de Néphrologie, Dialyse et Hypertension Artérielle, Hôpital E Herriot, F-69003 Lyon, France.
- Université de Lyon, INSERM U1060, CarMeN, INSA de Lyon, Univ Lyon-1, F-69621 Villeurbanne, France.
| | - Fitsum Guebre-Egziabher
- Hospices Civils de Lyon, Service de Néphrologie, Dialyse et Hypertension Artérielle, Hôpital E Herriot, F-69003 Lyon, France.
- Université de Lyon, INSERM U1060, CarMeN, INSA de Lyon, Univ Lyon-1, F-69621 Villeurbanne, France.
| | - Laurent Juillard
- Hospices Civils de Lyon, Service de Néphrologie, Dialyse et Hypertension Artérielle, Hôpital E Herriot, F-69003 Lyon, France.
- Université de Lyon, INSERM U1060, CarMeN, INSA de Lyon, Univ Lyon-1, F-69621 Villeurbanne, France.
| | - Christophe O Soulage
- Université de Lyon, INSERM U1060, CarMeN, INSA de Lyon, Univ Lyon-1, F-69621 Villeurbanne, France.
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19
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Zhao Y, Li M, Li B, Zhang S, Su A, Xing Y, Ge Z, Li R, Yang B. Discovery and optimization of thienopyridine derivatives as novel urea transporter inhibitors. Eur J Med Chem 2019; 172:131-142. [PMID: 30959323 DOI: 10.1016/j.ejmech.2019.03.060] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 03/26/2019] [Accepted: 03/28/2019] [Indexed: 10/27/2022]
Abstract
Urea transporters (UTs) play an important role in the urine concentrating mechanism and are recognized as novel targets for developing small molecule inhibitors with salt-sparing diuretic activity. Thienoquinoline derivatives, a class of novel UT-B inhibitors identified by our group, play a significant diuresis in animal model. However, the poor solubility and low bioavailability limited its further development. To overcome these shortcomings, the structure modification of thienoquinoline was carried out in this study, which led to the discovery of novel thienopyridine derivatives as specific urea transporter inhibitors. Further optimization obtained the promising preclinical candidate 8n with not only excellent inhibition effect on urea transporters and diuretic activity on rat model, but also suitable water solubility and Log P value.
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Affiliation(s)
- Yan Zhao
- State Key Laboratory of Natural and Biomimetic Drugs, School of pharmaceutical Sciences, Peking University, 100191, PR, China; College of Pharmacy, Inner Mongolia Medical University, 010110, PR, China
| | - Min Li
- Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, 100191, PR, China
| | - Bowen Li
- State Key Laboratory of Natural and Biomimetic Drugs, School of pharmaceutical Sciences, Peking University, 100191, PR, China
| | - Shun Zhang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, 100191, PR, China
| | - Aoze Su
- State Key Laboratory of Natural and Biomimetic Drugs, School of pharmaceutical Sciences, Peking University, 100191, PR, China
| | - Yongning Xing
- State Key Laboratory of Natural and Biomimetic Drugs, School of pharmaceutical Sciences, Peking University, 100191, PR, China
| | - Zemei Ge
- State Key Laboratory of Natural and Biomimetic Drugs, School of pharmaceutical Sciences, Peking University, 100191, PR, China
| | - Runtao Li
- State Key Laboratory of Natural and Biomimetic Drugs, School of pharmaceutical Sciences, Peking University, 100191, PR, China.
| | - Baoxue Yang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, 100191, PR, China.
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20
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Xiao L, Liu D, Zuo S, Zhu X, Wang Y, Dong C. Urea-modulated UT-B urea transporter internalization is clathrin- and caveolae-dependent in infantile hemangioma-derived vascular endothelial cells. J Cell Biochem 2019; 120:5128-5136. [PMID: 30367514 DOI: 10.1002/jcb.27789] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/10/2018] [Indexed: 11/10/2022]
Abstract
The aim of this study was to investigate the manner of urea-modulated UT-B urea transporter (UT) internalization in infantile hemangioma-derived vascular endothelial cells (HemECs). The immunohistochemistry assay was performed to identify infancy hemangioma-derived endothelial cell line (XPTS-1) cells. Cell toxicity was detected with the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. Quantitative real-time polymerase chain reaction and Western blot analysis were measured to analyze the expression of UT-B. UT-B internalization was observed by confocal microscopy. The clathrin inhibitor chlorpromazine (CPZ) and caveolin endocytic disrupter methyl-β-cyclodextrin (MβCD) were used in XPTS-1 cells transfected with UT-B-GFP to repress endocytosis. Urea-promoted UT-B expression in a concentration-dependent manner in an infantile XPTS-1 cell line. CPZ and MβCD significantly inhibited UT-B protein internalization. The pretreatment of UT-B-GFP cells with adaptor protein2 (AP2)-μ2-siRNA and caveolin-siRNA significantly inhibited UT-B protein internalization. Our findings suggested that urea-mediated UT-B UT internalization is clathrin and caveolae dependent in infantile HemECs.
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Affiliation(s)
- Li Xiao
- Department of Hemangioma, Henan Provincial People's Hospital, Zhengzhou, Henan, China
| | - Dakan Liu
- Department of Hemangioma, Henan Provincial People's Hospital, Zhengzhou, Henan, China
| | - Song Zuo
- Department of Hemangioma, Henan Provincial People's Hospital, Zhengzhou, Henan, China
| | - Xiaoshuang Zhu
- Department of Hemangioma, Henan Provincial People's Hospital, Zhengzhou, Henan, China
| | - Yanlin Wang
- Department of Hemangioma, Henan Provincial People's Hospital, Zhengzhou, Henan, China
| | - Changxian Dong
- Department of Hemangioma, Henan Provincial People's Hospital, Zhengzhou, Henan, China
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21
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Ilatovskaya DV, Levchenko V, Pavlov TS, Isaeva E, Klemens CA, Johnson J, Liu P, Kriegel AJ, Staruschenko A. Salt-deficient diet exacerbates cystogenesis in ARPKD via epithelial sodium channel (ENaC). EBioMedicine 2019; 40:663-674. [PMID: 30745171 PMCID: PMC6413684 DOI: 10.1016/j.ebiom.2019.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/04/2019] [Accepted: 01/05/2019] [Indexed: 12/14/2022] Open
Abstract
Background Autosomal Recessive Polycystic Kidney Disease (ARPKD) is marked by cyst formation in the renal tubules, primarily in the collecting duct (CD) system, ultimately leading to end-stage renal disease. Patients with PKD are generally advised to restrict their dietary sodium intake. This study was aimed at testing the outcomes of dietary salt manipulation in ARPKD. Methods PCK/CrljCrlPkhd1pck/CRL (PCK) rats, a model of ARPKD, were fed a normal (0.4% NaCl; NS), high salt (4% NaCl; HS), and sodium-deficient (0.01% NaCl; SD) diets for 8 weeks. Immunohistochemistry, GFR measurements, balance studies, and molecular biology approaches were applied to evaluate the outcomes of the protocol. Renin-angiotensin-aldosterone system (RAAS) levels were assessed using LC-MS/MS, and renal miRNA profiles were studied. Findings Both HS and SD diets resulted in an increase in cystogenesis. However, SD diet caused extensive growth of cysts in the renal cortical area, and hypertrophy of the tissue; RAAS components were enhanced in the SD group. We observed a reduction in epithelial Na+ channel (ENaC) expression in the SD group, accompanied with mRNA level increase. miRNA assay revealed that renal miR-9a-5p level was augmented in the SD group; we showed that this miRNA decreases ENaC channel number in CD cells. Interpretation Our data demonstrate a mechanism of ARPKD progression during salt restriction that involves activity of ENaC. We further show that miR-9a-5p potentially implicated in this mechanism and that miR-9a-5p downregulates ENaC in cultured CD cells. Our findings open new therapeutic possibilities and highlight the importance of understanding salt reabsorption in ARPKD.
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Affiliation(s)
- Daria V Ilatovskaya
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Tengis S Pavlov
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Elena Isaeva
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Christine A Klemens
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Jessica Johnson
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Pengyuan Liu
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Alison J Kriegel
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA; Clement J. Zablocki VA Medical Center, 5000 West National Avenue, Milwaukee, WI, 53295, USA.
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22
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Cherezova A, Tomilin V, Buncha V, Zaika O, Ortiz PA, Mei F, Cheng X, Mamenko M, Pochynyuk O. Urinary concentrating defect in mice lacking Epac1 or Epac2. FASEB J 2019; 33:2156-2170. [PMID: 30252533 PMCID: PMC6338637 DOI: 10.1096/fj.201800435r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/27/2018] [Indexed: 11/11/2022]
Abstract
cAMP is a universal second messenger regulating a plethora of processes in the kidney. Two downstream effectors of cAMP are PKA and exchange protein directly activated by cAMP (Epac), which, unlike PKA, is often linked to elevation of [Ca2+]i. While both Epac isoforms (Epac1 and Epac2) are expressed along the nephron, their relevance in the kidney remains obscure. We combined ratiometric calcium imaging with quantitative immunoblotting, immunofluorescent confocal microscopy, and balance studies in mice lacking Epac1 or Epac2 to determine the role of Epac in renal water-solute handling. Epac1-/- and Epac2-/- mice developed polyuria despite elevated arginine vasopressin levels. We did not detect major deficiencies in arginine vasopressin [Ca2+]i signaling in split-opened collecting ducts or decreases in aquaporin water channel type 2 levels. Instead, sodium-hydrogen exchanger type 3 levels in the proximal tubule were dramatically reduced in Epac1-/- and Epac2-/- mice. Water deprivation revealed persisting polyuria, impaired urinary concentration ability, and augmented urinary excretion of Na+ and urea in both mutant mice. In summary, we report a nonredundant contribution of Epac isoforms to renal function. Deletion of Epac1 and Epac2 decreases sodium-hydrogen exchanger type 3 expression in the proximal tubule, leading to polyuria and osmotic diuresis.-Cherezova, A., Tomilin, V., Buncha, V., Zaika, O., Ortiz, P. A., Mei, F., Cheng, X., Mamenko, M., Pochynyuk, O. Urinary concentrating defect in mice lacking Epac1 or Epac2.
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Affiliation(s)
- Alena Cherezova
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Viktor Tomilin
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Vadym Buncha
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Oleg Zaika
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Pablo A. Ortiz
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan, USA; and
| | - Fang Mei
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
- Texas Therapeutics Institute, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Mykola Mamenko
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Oleh Pochynyuk
- Department of Integrative Biology and Pharmacology The University of Texas Health Science Center at Houston, Houston, Texas, USA
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23
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Lee S, Cil O, Diez-Cecilia E, Anderson MO, Verkman AS. Nanomolar-Potency 1,2,4-Triazoloquinoxaline Inhibitors of the Kidney Urea Transporter UT-A1. J Med Chem 2018; 61:3209-3217. [PMID: 29589443 PMCID: PMC5976253 DOI: 10.1021/acs.jmedchem.8b00343] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Urea transporter A (UT-A) isoforms encoded by the Slc14a2 gene are expressed in kidney tubule epithelial cells, where they facilitate urinary concentration. UT-A1 inhibition is predicted to produce a unique salt-sparing diuretic action in edema and hyponatremia. Here we report the discovery of 1,2,4-triazoloquinoxalines and the analysis of 37 synthesized analogues. The most potent compound, 8ay, containing 1,2,4-triazolo[4,3- a]quinoxaline-substituted benzenesulfonamide linked by an aryl ether, rapidly and reversibly inhibited UT-A1 urea transport by a noncompetitive mechanism with IC50 ≈ 150 nM; the IC50 was ∼2 μM for the related urea transporter UT-B encoded by the Slc14a1 gene. Molecular modeling suggested a putative binding site on the UT-A1 cytoplasmic domain. In vitro metabolism showing quinoxaline ring oxidation prompted the synthesis of metabolically stable 7,8-difluoroquinoxaline analogue 8bl, which when administered to rats produced marked diuresis and reduced urinary osmolality. 8bl has substantially improved UT-A1 inhibition potency and metabolic stability compared with prior compounds.
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Affiliation(s)
- Sujin Lee
- Departments of Medicine and Physiology, University of California, San Francisco, California 94143-0521, United States
| | - Onur Cil
- Departments of Medicine and Physiology, University of California, San Francisco, California 94143-0521, United States
- Department of Pediatrics, Division of Nephrology, University of California, San Francisco, California 94143-0521, United States
| | - Elena Diez-Cecilia
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California 94132-1722, United States
| | - Marc O. Anderson
- Departments of Medicine and Physiology, University of California, San Francisco, California 94143-0521, United States
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California 94132-1722, United States
| | - Alan S. Verkman
- Departments of Medicine and Physiology, University of California, San Francisco, California 94143-0521, United States
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24
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Hinze C, Ruffert J, Walentin K, Himmerkus N, Nikpey E, Tenstad O, Wiig H, Mutig K, Yurtdas ZY, Klein JD, Sands JM, Branchi F, Schumann M, Bachmann S, Bleich M, Schmidt-Ott KM. GRHL2 Is Required for Collecting Duct Epithelial Barrier Function and Renal Osmoregulation. J Am Soc Nephrol 2017; 29:857-868. [PMID: 29237740 DOI: 10.1681/asn.2017030353] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 11/09/2017] [Indexed: 12/31/2022] Open
Abstract
Collecting ducts make up the distal-most tubular segments of the kidney, extending from the cortex, where they connect to the nephron proper, into the medulla, where they release urine into the renal pelvis. During water deprivation, body water preservation is ensured by the selective transepithelial reabsorption of water into the hypertonic medullary interstitium mediated by collecting ducts. The collecting duct epithelium forms tight junctions composed of barrier-enforcing claudins and exhibits a higher transepithelial resistance than other segments of the renal tubule exhibit. However, the functional relevance of this strong collecting duct epithelial barrier is unresolved. Here, we report that collecting duct-specific deletion of an epithelial transcription factor, grainyhead-like 2 (GRHL2), in mice led to reduced expression of tight junction-associated barrier components, reduced collecting duct transepithelial resistance, and defective renal medullary accumulation of sodium and other osmolytes. In vitro, Grhl2-deficient collecting duct cells displayed increased paracellular flux of sodium, chloride, and urea. Consistent with these effects, Grhl2-deficient mice had diabetes insipidus, produced dilute urine, and failed to adequately concentrate their urine after water restriction, resulting in susceptibility to prerenal azotemia. These data indicate a direct functional link between collecting duct epithelial barrier characteristics, which appear to prevent leakage of interstitial osmolytes into urine, and body water homeostasis.
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Affiliation(s)
- Christian Hinze
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany.,Departments of Nephrology and Medical Intensive Care
| | - Janett Ruffert
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Berlin Institute of Urologic Research, Berlin, Germany
| | - Katharina Walentin
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Nina Himmerkus
- Institute of Physiology, Christian Albrechts University Kiel, Kiel, Germany
| | - Elham Nikpey
- Department of Biomedicine, University of Bergen, Bergen, Norway.,Department of Medicine, Haukeland University Hospital, Bergen, Norway; and
| | - Olav Tenstad
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Helge Wiig
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Zeliha Yesim Yurtdas
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Berlin Institute of Urologic Research, Berlin, Germany
| | - Janet D Klein
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia
| | - Jeff M Sands
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia
| | - Federica Branchi
- Gastroenterology, Infectious Diseases and Rheumatology, Charité Universitätsmedizin, Berlin, Germany
| | - Michael Schumann
- Gastroenterology, Infectious Diseases and Rheumatology, Charité Universitätsmedizin, Berlin, Germany
| | | | - Markus Bleich
- Institute of Physiology, Christian Albrechts University Kiel, Kiel, Germany
| | - Kai M Schmidt-Ott
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany; .,Departments of Nephrology and Medical Intensive Care
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25
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Hou R, Kong X, Yang B, Xie Y, Chen G. SLC14A1: a novel target for human urothelial cancer. Clin Transl Oncol 2017; 19:1438-1446. [PMID: 28589430 PMCID: PMC5700210 DOI: 10.1007/s12094-017-1693-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 05/26/2017] [Indexed: 12/23/2022]
Abstract
Urinary bladder cancer is the second commonly diagnosed genitourinary malignancy. Previously, bio-molecular alterations have been observed within certain locations such as chromosome 9, retinoblastoma gene and fibroblast growth factor receptor-3. Solute carrier family 14 member 1 (SLC14A1) gene encodes the type-B urea transporter (UT-B) which facilitates the passive movement of urea across cell membrane, and has recently been related with human malignancies, especially for bladder cancer. Herein, we discussed the SLC14A1 gene and UT-B protein properties, aiming to elucidate the expression behavior of SLC14A1 in human bladder cancer. Furthermore, by reviewing some well-established theories regarding the carcinogenesis of bladder cancer, including several genome wide association researches, we have bridged the mechanisms of cancer development with the aberrant expression of SLC14A1. In conclusion, the altered expression of SLC14A1 gene in human urothelial cancer may implicate its significance as a novel target for research.
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Affiliation(s)
- R Hou
- Department of Urology, China Japan Union Hospital, Jilin University, Changchun, 130033, Jilin, China
| | - X Kong
- Department of Urology, China Japan Union Hospital, Jilin University, Changchun, 130033, Jilin, China
| | - B Yang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Y Xie
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Xiangya School of Medicine, Central South University, Changsha, 410008, Hunan, China
| | - G Chen
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA.
- Department of Physiology, Emory University School of Medicine, Whitehead Research Building Room 615, 615 Michael Street, Atlanta, GA, 30322, USA.
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26
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Konopelniuk VV, Goloborodko II, Ishchuk TV, Synelnyk TB, Ostapchenko LI, Spivak MY, Bubnov RV. Efficacy of Fenugreek-based bionanocomposite on renal dysfunction and endogenous intoxication in high-calorie diet-induced obesity rat model-comparative study. EPMA J 2017; 8:377-390. [PMID: 29209440 PMCID: PMC5700020 DOI: 10.1007/s13167-017-0098-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 05/16/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Worldwide obesity spread is a global health problem and needs to be further studied. Co-morbidities of obesity include insulin resistance, diabetes mellitus type 2, and dyslipidemia, which are the most frequent contributing factors for metabolic syndrome (MetS), as well as non-alcoholic fatty liver disease and chronic kidney disease. The aim was to study renal function and endogenous intoxication panel on high-calorie diet-induced obesity rat model and perform comparative study of the treatment efficacy of Fenugreek-based bionanocomposite vs antiobesogenic drugs (Orlistat). MATERIALS We included 60 male rats and equally divided them to 6 groups of 10 animals in each group: the experimental groups were firstly assigned as controls and high caloric diet (HCD)-fed groups, and each group further was subdivided to remain untreated, Fenugreek bionanocomposite (BNC)-treated, and Orlistat-treated. Normal control rats (groups 1, 2, 3) were fed by a standard chow, while the others (groups 4, 5, 6) were fed with HCD ad libitum during 98 days. From days 77 to 98, groups 2 and 5 were treated with BNC based on Fenugreek (150 mg/kg body weight, orally) and groups 3 and 6 were treated with antiobesogenic drug Orlistat (10 mg/kg body weight, orally). Food and water consumptions were measured daily and body weights were measured once a week. On day 99, blood was collected; the creatinine, urea, and uric acid were estimated in serum according to the standard protocols. Levels of low and middle molecules (MMs) were measured; the quantity of oligopeptides was estimated by Bradford method. We performed the liver and kidney ultrasonography in rats. RESULTS We revealed an increase in the levels of endogenous intoxication syndrome markers (MM and oligopeptides) in all animals with experimental obesity. Ultrasound data showed injury of the liver and kidneys in obese rats. We observed significant decreasing of MM levels after Orlistat treatment vs controls (p < 0.05). However, this effect was more pronounced in Fenugreek BNC-treated group vs both Orlistat-treated and controls (p < 0.05). Orlistat treatment evoked rising of serum creatinine and oligopeptides in control animals and failed to normalize these markers in experimental group. Fenugreek-based BNC treatment did not evoke signs of kidney failure and changes in the studied indices in control group. We noticed normalization levels of uric acid and urea in the blood under the use of BNC and Orlistat. CONCLUSION High-calorie diet-induced obesity evokes endogenous intoxication syndrome and kidney dysfunction in rats. Application of Orlistat- and Fenugreek-based BNC decreases MM content to the normal level. Orlistat induces increasing levels of oligopeptides in both groups, likely due to adverse side effects on renal function and its pro-oxidant activity.
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Affiliation(s)
- Victoria V. Konopelniuk
- Educational and Scientific Centre “Institute of Biology”, Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, Kyiv, 01601 Ukraine
| | - Ievgenii I. Goloborodko
- Educational and Scientific Centre “Institute of Biology”, Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, Kyiv, 01601 Ukraine
| | - Tetyana V. Ishchuk
- Educational and Scientific Centre “Institute of Biology”, Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, Kyiv, 01601 Ukraine
| | - Tetyana B. Synelnyk
- Educational and Scientific Centre “Institute of Biology”, Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, Kyiv, 01601 Ukraine
| | - Ludmila I. Ostapchenko
- Educational and Scientific Centre “Institute of Biology”, Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, Kyiv, 01601 Ukraine
| | - Mykola Ya. Spivak
- Zabolotny Institute of Microbiology and Virology, National Academy of Sciences of Ukraine, Zabolotny Str., 154, Kyiv, 03143 Ukraine
| | - Rostyslav V. Bubnov
- Zabolotny Institute of Microbiology and Virology, National Academy of Sciences of Ukraine, Zabolotny Str., 154, Kyiv, 03143 Ukraine
- Clinical Hospital “Pheophania” of State Affairs Department, Zabolotny Str., 21, Kyiv, 03143 Ukraine
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27
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Hou R, Alemozaffar M, Yang B, Sands JM, Kong X, Chen G. Identification of a Novel UT-B Urea Transporter in Human Urothelial Cancer. Front Physiol 2017; 8:245. [PMID: 28503151 PMCID: PMC5409228 DOI: 10.3389/fphys.2017.00245] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/07/2017] [Indexed: 02/01/2023] Open
Abstract
The urea transporter UT-B is widely expressed and has been studied in erythrocyte, kidney, brain and intestines. Interestingly, UT-B gene has been found more abundant in bladder than any other tissue. Recently, gene analyses demonstrate that SLC14A1 (UT-B) gene mutations are associated with bladder cancer, suggesting that urea transporter UT-B may play an important role in bladder carcinogenesis. In this study, we examined UT-B expression in bladder cancer with human primary bladder cancer tissues and cancer derived cell lines. Human UT-B has two isoforms. We found that normal bladder expresses long form of UT-B2 but was lost in 8 of 24 (33%) or significantly downregulated in 16 of 24 (67%) of primary bladder cancer patients. In contrast, the short form of UT-B1 lacking exon 3 was detected in 20 bladder cancer samples. Surprisingly, a 24-nt in-frame deletion in exon 4 in UT-B1 (UT-B1Δ24) was identified in 11 of 20 (55%) bladder tumors. This deletion caused a functional defect of UT-B1. Immunohistochemistry revealed that UT-B protein levels were significantly decreased in bladder cancers. Western blot analysis showed a weak UT-B band of 40 kDa in some tumors, consistent with UT-B1 gene expression detected by RT-PCR. Interestingly, bladder cancer associate UT-B1Δ24 was barely sialylated, reflecting impaired glycosylation of UT-B1 in bladder tumors. In conclusion, SLC14A1 gene and UT-B protein expression are significantly changed in bladder cancers. The aberrant UT-B expression may promote bladder cancer development or facilitate carcinogenesis induced by other carcinogens.
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Affiliation(s)
- Ruida Hou
- Department of Urology, China-Japan Union Hospital, Jilin UniversityChangchun, China.,Department of Physiology, Emory University School of MedicineAtlanta, GA, USA
| | | | - Baoxue Yang
- Department of Pharmacology, School of Basic Medical Sciences, Peking UniversityBeijing, China
| | - Jeff M Sands
- Department of Physiology, Emory University School of MedicineAtlanta, GA, USA.,Renal Division Department of Medicine, Emory University School of MedicineAtlanta, GA, USA
| | - Xiangbo Kong
- Department of Urology, China-Japan Union Hospital, Jilin UniversityChangchun, China
| | - Guangping Chen
- Department of Physiology, Emory University School of MedicineAtlanta, GA, USA.,Renal Division Department of Medicine, Emory University School of MedicineAtlanta, GA, USA
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28
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Chng YR, Ong JLY, Ching B, Chen XL, Hiong KC, Wong WP, Chew SF, Lam SH, Ip YK. Aestivation Induces Changes in the mRNA Expression Levels and Protein Abundance of Two Isoforms of Urea Transporters in the Gills of the African Lungfish, Protopterus annectens. Front Physiol 2017; 8:71. [PMID: 28261105 PMCID: PMC5311045 DOI: 10.3389/fphys.2017.00071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 01/26/2017] [Indexed: 11/26/2022] Open
Abstract
The African lungfish, Protopterus annectens, is ammonotelic in water despite being ureogenic. When it aestivates in mucus cocoon on land, ammonia is detoxified to urea. During the maintenance phase of aestivation, urea accumulates in the body, which is subsequently excreted upon arousal. Urea excretion involves urea transporters (UT/Ut). This study aimed to clone and sequence the ut isoforms from the gills of P. annectens, and to test the hypothesis that the mRNA and/or protein expression levels of ut/Ut isoforms could vary in the gills of P. annectens during the induction, maintenance, and arousal phases of aestivation. Two isoforms of ut, ut-a2a and ut-a2b, were obtained from the gills of P. annectens. ut-a2a consisted of 1227 bp and coded for 408 amino acids with an estimated molecular mass of 44.7 kDa, while ut-a2b consisted of 1392 bp and coded for 464 amino acids with an estimated molecular mass of 51.2 kDa. Ut-a2a and Ut-a2b of P. annectens had a closer phylogenetic relationship with Ut/UT of tetrapods than Ut of fishes. While the mRNA expression pattern of ut-a2a and ut-a2b across various tissues of P. annectens differed, the transcript levels of ut-a2a and ut-a2b in the gills were comparable, indicating that they might be equally important for branchial urea excretion during the initial arousal phase of aestivation. During the maintenance phase of aestivation, the transcript level of ut-a2a increased significantly, but the protein abundance of Ut-a2a remained unchanged in the gills of P. annectens. This could be an adaptive feature to prepare for an increase in the production of Ut-a2a upon arousal. Indeed, arousal led to a significant increase in the branchial Ut-a2a protein abundance. Although the transcript level of ut-a2b remained unchanged, there were significant increases in the protein abundance of Ut-a2b in the gills of P. annectens throughout the three phases of aestivation. The increase in the protein abundance of Ut-a2b during the maintenance phase could also be an adaptive feature to prepare for efficient urea excretion when water becomes available.
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Affiliation(s)
- You R. Chng
- Department of Biological Sciences, National University of SingaporeSingapore, Singapore
| | - Jasmine L. Y. Ong
- Department of Biological Sciences, National University of SingaporeSingapore, Singapore
| | - Biyun Ching
- Department of Biological Sciences, National University of SingaporeSingapore, Singapore
| | - Xiu L. Chen
- Department of Biological Sciences, National University of SingaporeSingapore, Singapore
| | - Kum C. Hiong
- Department of Biological Sciences, National University of SingaporeSingapore, Singapore
| | - Wai P. Wong
- Department of Biological Sciences, National University of SingaporeSingapore, Singapore
| | - Shit F. Chew
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological UniversitySingapore, Singapore
| | - Siew H. Lam
- Department of Biological Sciences, National University of SingaporeSingapore, Singapore
- NUS Environmental Research Institute, National University of SingaporeSingapore, Singapore
| | - Yuen K. Ip
- Department of Biological Sciences, National University of SingaporeSingapore, Singapore
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Ilatovskaya DV, Palygin O, Staruschenko A. Functional and therapeutic importance of purinergic signaling in polycystic kidney disease. Am J Physiol Renal Physiol 2016; 311:F1135-F1139. [PMID: 27654892 DOI: 10.1152/ajprenal.00406.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 09/20/2016] [Indexed: 12/12/2022] Open
Abstract
Polycystic kidney diseases (PKD) are a group of inherited nephropathies marked with the formation of fluid-filled cysts along the nephron. This renal disorder affects millions of people worldwide, but current treatment strategies are unfortunately limited to supportive therapy, dietary restrictions, and, eventually, renal transplantation. Recent advances in PKD management are aimed at targeting exaggerated cell proliferation and dedifferentiation to interfere with cyst growth. However, not nearly enough is known about the ion transport properties of the cystic cells, or specific signaling pathways modulating channels and transporters in this condition. There is growing evidence that abnormally elevated concentrations of adenosine triphosphate (ATP) in PKD may contribute to cyst enlargement; change in the profile of purinergic receptors may also result in promotion of cystogenesis. The current mini-review is focused on the role of ATP and associated signaling affecting ion transport properties of the renal cystic epithelia.
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Affiliation(s)
- Daria V Ilatovskaya
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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Abstract
PURPOSE OF REVIEW Urea is transported by urea transporter proteins in kidney, erythrocytes, and other tissues. Mice in which different urea transporters have been knocked out have urine-concentrating defects, which has led to the development and testing of urea transporters Slc14A2 (UT-A) and Slc14A1 (UT-B) inhibitors as urearetics. This review summarizes the knowledge gained during the past year on urea transporter regulation and investigations into the clinical potential of urearetics. RECENT FINDINGS UT-A1 undergoes several posttranslational modifications that increase its function by increasing UT-A1 accumulation in the apical plasma membrane. UT-A1 is phosphorylated by protein kinase A, exchange protein activated by cyclic AMP, protein kinase Cα, and AMP-activated protein kinase, all at different serine residues. UT-A1 is also regulated by 14-3-3, which contributes to UT-A1 removal from the membrane. UT-A1 is glycosylated with various glycan moieties in animal models of diabetes mellitus. Transgenic expression of UT-A1 into UT-A1/UT-A3 knockout mice restores urine-concentrating ability. UT-B is present in descending vasa recta and urinary bladder, and is linked to bladder cancer. Inhibitors of UT-A and UT-B have been developed that result in diuresis with fewer abnormalities in serum electrolytes than conventional diuretics. SUMMARY Urea transporters play critical roles in the urine-concentrating mechanism. Urea transport inhibitors are a promising new class of diuretic agent.
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Affiliation(s)
- Janet D Klein
- Renal Division, Department of Medicine, and Department of Physiology, Emory University School of Medicine, Atlanta, Georgia, USA
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31
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Qian X, Sands JM, Song X, Chen G. Modulation of kidney urea transporter UT-A3 activity by alpha2,6-sialylation. Pflugers Arch 2016; 468:1161-1170. [PMID: 26972907 PMCID: PMC4945389 DOI: 10.1007/s00424-016-1802-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 02/16/2016] [Accepted: 02/23/2016] [Indexed: 10/22/2022]
Abstract
Two urea transporters, UT-A1 and UT-A3, are expressed in the kidney terminal inner medullary collecting duct (IMCD) and are important for the production of concentrated urine. UT-A1, as the largest isoform of all UT-A urea transporters, has gained much attention and been extensively studied; however, the role and the regulation of UT-A3 are less explored. In this study, we investigated UT-A3 regulation by glycosylation modification. A site-directed mutagenesis verified a single glycosylation site in UT-A3 at Asn279. Loss of the glycosylation reduced forskolin-stimulated UT-A3 cell membrane expression and urea transport activity. UT-A3 has two glycosylation forms, 45 and 65 kDa. Using sugar-specific binding lectins, the UT-A3 glycosylation profile was examined. The 45-kDa form was pulled down by lectin concanavalin A (Con A) and Galant husnivalis lectin (GNL), indicating an immature glycan with a high amount of mannose (Man), whereas the 65-kDa form is a mature glycan composed of acetylglucosamine (GlcNAc) and poly-N-acetyllactosame (poly-LacNAc) that was pulled down by wheat germ agglutinin (WGA) and tomato lectin, respectively. Interestingly, the mature form of UT-A3 glycan contains significant amounts of sialic acid. We explored the enzymes responsible for directing UT-A3 sialylation. Sialyltransferase ST6GalI, but not ST3GalIV, catabolizes UT-A3 α2,6-sialylation. Activation of protein kinase C (PKC) by PDB treatment promoted UT-A3 glycan sialylation and membrane surface expression. The PKC inhibitor chelerythrine blocks ST6GalI-induced UT-A3 sialylation. Increased sialylation by ST6GalI increased UT-A3 protein stability and urea transport activity. Collectively, our study reveals a novel mechanism of UT-A3 regulation by ST6GalI-mediated sialylation modification that may play an important role in kidney urea reabsorption and the urinary concentrating mechanism.
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Affiliation(s)
- Xiaoqian Qian
- Department of Physiology, Emory University, Atlanta, GA 30322, USA
- Cardiovascular Center, the 4 affiliated hospital, Harbin Medical University, Heilongjiang 150001, China
| | - Jeff M. Sands
- Department of Physiology, Emory University, Atlanta, GA 30322, USA
- Renal Division, Department of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Xiang Song
- Cardiovascular Center, the 4 affiliated hospital, Harbin Medical University, Heilongjiang 150001, China
| | - Guangping Chen
- Department of Physiology, Emory University, Atlanta, GA 30322, USA
- Renal Division, Department of Medicine, Emory University, Atlanta, GA 30322, USA
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Urea Transporter B and MicroRNA-200c Differ in Kidney Outer Versus Inner Medulla Following Dehydration. Am J Med Sci 2016; 352:296-301. [PMID: 27650235 DOI: 10.1016/j.amjms.2016.06.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 05/27/2016] [Accepted: 06/03/2016] [Indexed: 11/20/2022]
Abstract
BACKGROUND Urea transporters (UTs) are important in urine concentration and in urea recycling, and UT-B has been implicated in both. In kidney, UT-B was originally localized to outer medullary descending vasa recta, and more recently detected in inner medullary descending vasa recta. Endogenously produced microRNAs (miRs) bind to the 3'UTR of genes and generally inhibit their translation, thus playing a pivotal role gene regulation. METHODS Mice were dehydrated for 24 hours then sacrificed. Inner and outer medullas were analyzed by polymerase chain reaction (PCR) and quantitative PCR for miRNA expression and analyzed by western blotting for protein abundance. RESULTS MiRNA sequencing analysis of mouse inner medullas showed a 40% increase in miRNA-200c in dehydrated mice compared with controls. An in silico analysis of the targets for miR-200c revealed that miRNA-200c could directly target the gene for UT-B. PCR confirmed that miR-200c is up-regulated in the inner medullas of dehydrated mice while western blot showed that UT-B protein abundance was down-regulated in the same portion of the kidney. However, in the outer medulla, miR-200c was reduced and UT-B protein was increased in dehydrated mice. CONCLUSIONS This is the first indication that UT-B protein and miR-200c may each be differentially regulated by dehydration within the kidney outer and inner medulla. The inverse correlation between the direction of change in miR-200c and UT-B protein abundance in both the inner and outer medulla suggests that miR-200c may be associated with the change in UT-B protein in these 2 portions of the kidney medulla.
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Klein JD, Wang Y, Blount MA, Molina PA, LaRocque LM, Ruiz JA, Sands JM. Metformin, an AMPK activator, stimulates the phosphorylation of aquaporin 2 and urea transporter A1 in inner medullary collecting ducts. Am J Physiol Renal Physiol 2016; 310:F1008-12. [PMID: 26962099 PMCID: PMC4889320 DOI: 10.1152/ajprenal.00102.2016] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 03/02/2016] [Indexed: 11/22/2022] Open
Abstract
Nephrogenic diabetes insipidus (NDI) is characterized by production of very large quantities of dilute urine due to an inability of the kidney to respond to vasopressin. Congenital NDI results from mutations in the type 2 vasopressin receptor (V2R) in ∼90% of families. These patients do not have mutations in aquaporin-2 (AQP2) or urea transporter UT-A1 (UT-A1). We tested adenosine monophosphate kinase (AMPK) since it is known to phosphorylate another vasopressin-sensitive transporter, NKCC2 (Na-K-2Cl cotransporter). We found AMPK expressed in rat inner medulla (IM). AMPK directly phosphorylated AQP2 and UT-A1 in vitro. Metformin, an AMPK activator, increased phosphorylation of both AQP2 and UT-A1 in rat inner medullary collecting ducts (IMCDs). Metformin increased the apical plasma membrane accumulation of AQP2, but not UT-A1, in rat IM. Metformin increased both osmotic water permeability and urea permeability in perfused rat terminal IMCDs. These findings suggest that metformin increases osmotic water permeability by increasing AQP2 accumulation in the apical plasma membrane but increases urea permeability by activating UT-A1 already present in the membrane. Lastly, metformin increased urine osmolality in mice lacking a V2R, a mouse model of congenital NDI. We conclude that AMPK activation by metformin mimics many of the mechanisms by which vasopressin increases urine-concentrating ability. These findings suggest that metformin may be a novel therapeutic option for congenital NDI due to V2R mutations.
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Affiliation(s)
- Janet D Klein
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia; and Department of Physiology, Emory University, Atlanta, Georgia
| | - Yanhua Wang
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia; and
| | - Mitsi A Blount
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia; and Department of Physiology, Emory University, Atlanta, Georgia
| | - Patrick A Molina
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia; and
| | - Lauren M LaRocque
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia; and
| | - Joseph A Ruiz
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia; and
| | - Jeff M Sands
- Renal Division, Department of Medicine, Emory University, Atlanta, Georgia; and Department of Physiology, Emory University, Atlanta, Georgia
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Klein JD, Wang Y, Mistry A, LaRocque LM, Molina PA, Rogers RT, Blount MA, Sands JM. Transgenic Restoration of Urea Transporter A1 Confers Maximal Urinary Concentration in the Absence of Urea Transporter A3. J Am Soc Nephrol 2016; 27:1448-55. [PMID: 26407594 PMCID: PMC4849813 DOI: 10.1681/asn.2014121267] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 08/09/2015] [Indexed: 11/03/2022] Open
Abstract
Urea has a critical role in urinary concentration. Mice lacking the inner medullary collecting duct (IMCD) urea transporter A1 (UT-A1) and urea transporter A3 (UT-A3) have very low levels of urea permeability and are unable to concentrate urine. To investigate the role of UT-A1 in the concentration of urine, we transgenically expressed UT-A1 in knockout mice lacking UT-A1 and UT-A3 using a construct with a UT-A1 gene that cannot be spliced to produce UT-A3. This construct was inserted behind the original UT-A promoter to yield a mouse expressing only UT-A1 (UT-A1(+/+)/UT-A3(-/-)). Western blot analysis demonstrated UT-A1 in the inner medulla of UT-A1(+/+)/UT-A3(-/-) and wild-type mice, but not in UT-A1/UT-A3 knockout mice, and an absence of UT-A3 in UT-A1(+/+)/UT-A3(-/-) and UT-A1/UT-A3 knockout mice. Immunohistochemistry in UT-A1(+/+)/UT-A3(-/-) mice also showed negative UT-A3 staining in kidney and other tissues and positive UT-A1 staining only in the IMCD. Urea permeability in isolated perfused IMCDs showed basal permeability in the UT-A1(+/+)/UT-A3(-/-) mice was similar to levels in wild-type mice, but vasopressin stimulation of urea permeability in wild-type mice was significantly greater (100% increase) than in UT-A1(+/+)/UT-A3(-/-) mice (8% increase). Notably, basal urine osmolalities in both wild-type and UT-A1(+/+)/UT-A3(-/-) mice increased upon overnight water restriction. We conclude that transgenic expression of UT-A1 restores basal urea permeability to the level in wild-type mice but does not restore vasopressin-stimulated levels of urea permeability. This information suggests that transgenic expression of UT-A1 alone in mice lacking UT-A1 and UT-A3 is sufficient to restore urine-concentrating ability.
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Affiliation(s)
- Janet D Klein
- Renal Division, Department of Medicine, and Department of Physiology, Emory University, Atlanta, Georgia
| | | | | | | | | | | | - Mitsi A Blount
- Renal Division, Department of Medicine, and Department of Physiology, Emory University, Atlanta, Georgia
| | - Jeff M Sands
- Renal Division, Department of Medicine, and Department of Physiology, Emory University, Atlanta, Georgia
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35
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Sun Y, Lau CW, Jia Y, Li Y, Wang W, Ran J, Li F, Huang Y, Zhou H, Yang B. Functional inhibition of urea transporter UT-B enhances endothelial-dependent vasodilatation and lowers blood pressure via L-arginine-endothelial nitric oxide synthase-nitric oxide pathway. Sci Rep 2016; 6:18697. [PMID: 26739766 PMCID: PMC4703984 DOI: 10.1038/srep18697] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 11/23/2015] [Indexed: 12/25/2022] Open
Abstract
Mammalian urea transporters (UTs), UT-A and UT-B, are best known for their role in urine concentration. UT-B is especially distributed in multiple extrarenal tissues with abundant expression in vascular endothelium, but little is known about its role in vascular function. The present study investigated the physiological significance of UT-B in regulating vasorelaxations and blood pressure. UT-B deletion in mice or treatment with UT-B inhibitor PU-14 in Wistar-Kyoto rats (WKYs) and spontaneous hypertensive rats (SHRs) reduced blood pressure. Acetylcholine-induced vasorelaxation was significantly augmented in aortas from UT-B null mice. PU-14 concentration-dependently produced endothelium-dependent relaxations in thoracic aortas and mesenteric arteries from both mice and rats and the relaxations were abolished by N(ω)-nitro-L-arginine methyl ester. Both expression and phosphorylation of endothelial nitric oxide synthase (eNOS) were up-regulated and expression of arginase I was down-regulated when UT-B was inhibited both in vivo and in vitro. PU-14 induced endothelium-dependent relaxations to a similar degree in aortas from 12 weeks old SHRs or WKYs. In summary, here we report for the first time that inhibition of UT-B plays an important role in regulating vasorelaxations and blood pressure via up-regulation of L-arginine-eNOS-NO pathway, and it may become another potential therapeutic target for the treatment of hypertension.
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Affiliation(s)
- Yi Sun
- State Key Laboratory of Natural and Biomimetic Drugs, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Chi-Wai Lau
- Institute of Vascular Medicine and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Yingli Jia
- State Key Laboratory of Natural and Biomimetic Drugs, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Yingjie Li
- State Key Laboratory of Natural and Biomimetic Drugs, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Weiling Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Jianhua Ran
- Department of Anatomy and Neuroscience Center, Chongqing Medical University, Chongqing, China
| | - Fei Li
- State Key Laboratory of Natural and Biomimetic Drugs, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Yu Huang
- Institute of Vascular Medicine and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Hong Zhou
- State Key Laboratory of Natural and Biomimetic Drugs, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Baoxue Yang
- State Key Laboratory of Natural and Biomimetic Drugs, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
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36
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Blount MA, Cipriani P, Redd SK, Ordas RJ, Black LN, Gumina DL, Hoban CA, Klein JD, Sands JM. Activation of protein kinase Cα increases phosphorylation of the UT-A1 urea transporter at serine 494 in the inner medullary collecting duct. Am J Physiol Cell Physiol 2015; 309:C608-15. [PMID: 26333598 PMCID: PMC4628937 DOI: 10.1152/ajpcell.00171.2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 08/18/2015] [Indexed: 01/20/2023]
Abstract
Hypertonicity increases urea transport, as well as the phosphorylation and membrane accumulation of UT-A1, the transporter responsible for urea permeability in the inner medullary collect duct (IMCD). Hypertonicity stimulates urea transport through PKC-mediated phosphorylation. To determine whether PKC phosphorylates UT-A1, eight potential PKC phosphorylation sites were individually replaced with alanine and subsequently transfected into LLC-PK1 cells. Of the single mutants, only ablation of the S494 site dampened induction of total UT-A1 phosphorylation by the PKC activator phorbol dibutyrate (PDBu). This result was confirmed using a newly generated antibody that specifically detected phosphorylation of UT-A1 at S494. Hypertonicity increased UT-A1 phosphorylation at S494. In contrast, activators of cAMP pathways (PKA and Epac) did not increase UT-A1 phosphorylation at S494. Activation of both PKC and PKA pathways increased plasma membrane accumulation of UT-A1, although activation of PKC alone did not do so. However, ablating the PKC site S494 decreased UT-A1 abundance in the plasma membrane. This suggests that the cAMP pathway promotes UT-A1 trafficking to the apical membrane where the PKC pathway can phosphorylate the transporter, resulting in increased UT-A1 retention at the apical membrane. In summary, activation of PKC increases the phosphorylation of UT-A1 at a specific residue, S494. Although there is no cross talk with the cAMP-signaling pathway, phosphorylation of S494 through PKC may enhance vasopressin-stimulated urea permeability by retaining UT-A1 in the plasma membrane.
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Affiliation(s)
- Mitsi A Blount
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; and Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Penelope Cipriani
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; and
| | - Sara K Redd
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; and
| | - Ronald J Ordas
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; and
| | - Lauren N Black
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; and
| | - Diane L Gumina
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; and
| | - Carol A Hoban
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; and
| | - Janet D Klein
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; and Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Jeff M Sands
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; and Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
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Weiner ID, Mitch WE, Sands JM. Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion. Clin J Am Soc Nephrol 2015; 10:1444-58. [PMID: 25078422 PMCID: PMC4527031 DOI: 10.2215/cjn.10311013] [Citation(s) in RCA: 241] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance.
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Affiliation(s)
- I David Weiner
- Nephrology and Hypertension Section, North Florida/South Georgia Veterans Health System, Gainesville, Florida; Division of Nephrology, Hypertension, and Transplantation, University of Florida College of Medicine, Gainesville, Florida;
| | - William E Mitch
- Nephrology Division, Baylor College of Medicine, Houston, Texas; and
| | - Jeff M Sands
- Nephrology Division, Emory University School of Medicine, Atlanta, Georgia
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Kishore BK, Carlson NG, Ecelbarger CM, Kohan DE, Müller CE, Nelson RD, Peti-Peterdi J, Zhang Y. Targeting renal purinergic signalling for the treatment of lithium-induced nephrogenic diabetes insipidus. Acta Physiol (Oxf) 2015; 214:176-88. [PMID: 25877068 PMCID: PMC4430398 DOI: 10.1111/apha.12507] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 04/08/2015] [Indexed: 12/26/2022]
Abstract
Lithium still retains its critical position in the treatment of bipolar disorder by virtue of its ability to prevent suicidal tendencies. However, chronic use of lithium is often limited by the development of nephrogenic diabetes insipidus (NDI), a debilitating condition. Lithium-induced NDI is due to resistance of the kidney to arginine vasopressin (AVP), leading to polyuria, natriuresis and kaliuresis. Purinergic signalling mediated by extracellular nucleotides (ATP/UTP), acting via P2Y receptors, opposes the action of AVP on renal collecting duct (CD) by decreasing the cellular cAMP and thus AQP2 protein levels. Taking a cue from this phenomenon, we discovered the potential involvement of ATP/UTP-activated P2Y2 receptor in lithium-induced NDI in rats and showed that P2Y2 receptor knockout mice are significantly resistant to Li-induced polyuria, natriuresis and kaliuresis. Extension of these studies revealed that ADP-activated P2Y12 receptor is expressed in the kidney, and its irreversible blockade by the administration of clopidogrel bisulphate (Plavix(®)) ameliorates Li-induced NDI in rodents. Parallel in vitro studies showed that P2Y12 receptor blockade by the reversible antagonist PSB-0739 sensitizes CD to the action of AVP. Thus, our studies unravelled the potential beneficial effects of targeting P2Y2 or P2Y12 receptors to counter AVP resistance in lithium-induced NDI. If established in further studies, our findings may pave the way for the development of better and safer methods for the treatment of NDI by bringing a paradigm shift in the approach from the current therapies that predominantly counter the anti-AVP effects to those that enhance the sensitivity of the kidney to AVP action.
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Affiliation(s)
- B. K. Kishore
- Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
- Nephrology Research, Department of Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah, USA
- Center on Aging, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
| | - N. G. Carlson
- Center on Aging, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
- Department of Neurobiology and Anatomy, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
- Geriatric Research, Education and Clinical Center, Department of Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah, USA
| | - C. M. Ecelbarger
- Department of Medicine, Georgetown University, Washington, District of Columbia, USA
- Center for the Study of Sex Differences in Health, Aging, and Disease, Georgetown University, Washington, District of Columbia, USA
| | - D. E. Kohan
- Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
- Nephrology Research, Department of Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah, USA
| | - C. E. Müller
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, Bonn, Germany
| | - R. D. Nelson
- Department of Paediatrics, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
| | - J. Peti-Peterdi
- Department of Physiology and Biophysics, and Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California, USA
| | - Y. Zhang
- Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
- Nephrology Research, Department of Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah, USA
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Esteva-Font C, Phuan PW, Lee S, Su T, Anderson MO, Verkman AS. Structure-activity analysis of thiourea analogs as inhibitors of UT-A and UT-B urea transporters. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1848:1075-80. [PMID: 25613743 PMCID: PMC4364388 DOI: 10.1016/j.bbamem.2015.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 12/10/2014] [Accepted: 01/09/2015] [Indexed: 10/24/2022]
Abstract
Small-molecule inhibitors of urea transporter (UT) proteins in kidney have potential application as novel salt-sparing diuretics. The urea analog dimethylthiourea (DMTU) was recently found to inhibit the UT isoforms UT-A1 (expressed in kidney tubule epithelium) and UT-B (expressed in kidney vasa recta endothelium) with IC50 of 2-3 mM, and was shown to have diuretic action when administered to rats. Here, we measured UT-A1 and UT-B inhibition activity of 36 thiourea analogs, with the goal of identifying more potent and isoform-selective inhibitors, and establishing structure-activity relationships. The analog set systematically explored modifications of substituents on the thiourea including alkyl, heterocycles and phenyl rings, with different steric and electronic features. The analogs had a wide range of inhibition activities and selectivities. The most potent inhibitor, 3-nitrophenyl-thiourea, had an IC50 of ~0.2 mM for inhibition of both UT-A1 and UT-B. Some analogs such as 4-nitrophenyl-thiourea were relatively UT-A1 selective (IC50 1.3 vs. 10 mM), and others such as thioisonicotinamide were UT-B selective (IC50>15 vs. 2.8 mM).
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Affiliation(s)
- Cristina Esteva-Font
- Departments of Medicine and Physiology, University of California, San Francisco, CA 94143-0521, USA
| | - Puay-Wah Phuan
- Departments of Medicine and Physiology, University of California, San Francisco, CA 94143-0521, USA
| | - Sujin Lee
- Departments of Medicine and Physiology, University of California, San Francisco, CA 94143-0521, USA
| | - Tao Su
- Departments of Medicine and Physiology, University of California, San Francisco, CA 94143-0521, USA
| | - Marc O Anderson
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, CA 94132-4136, USA
| | - A S Verkman
- Departments of Medicine and Physiology, University of California, San Francisco, CA 94143-0521, USA.
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Wang J, Yu X, Hu B, Zheng J, Xiao W, Hao Y, Liu W, Wang D. Physicochemical evolution and molecular adaptation of the cetacean osmoregulation-related gene UT-A2 and implications for functional studies. Sci Rep 2015; 5:8795. [PMID: 25762239 PMCID: PMC4357013 DOI: 10.1038/srep08795] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 02/04/2015] [Indexed: 12/15/2022] Open
Abstract
Cetaceans have an enigmatic evolutionary history of re-invading aquatic habitats. One of their essential adaptabilities that has enabled this process is their homeostatic strategy adjustment. Here, we investigated the physicochemical evolution and molecular adaptation of the cetacean urea transporter UT-A2, which plays an important role in urine concentration and water homeostasis. First, we cloned UT-A2 from the freshwater Yangtze finless porpoise, after which bioinformatics analyses were conducted based on available datasets (including freshwater baiji and marine toothed and baleen whales) using MEGA, PAML, DataMonkey, TreeSAAP and Consurf. Our findings suggest that the UT-A2 protein shows folding similar to that of dvUT and UT-B, whereas some variations occurred in the functional So and Si regions of the selectivity filter. Additionally, several regions of the cetacean UT-A2 protein have experienced molecular adaptations. We suggest that positive-destabilizing selection could contribute to adaptations by influencing its biochemical and conformational character. The conservation of amino acid residues within the selectivity filter of the urea conduction pore is likely to be necessary for urea conduction, whereas the non-conserved amino acid replacements around the entrance and exit of the conduction pore could potentially affect the activity, which could be interesting target sites for future mutagenesis studies.
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Affiliation(s)
- Jingzhen Wang
- Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences; Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
- Marine Biology Institute, Shantou University, Shantou, Guangdong 515063, China
| | - Xueying Yu
- Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences; Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Bo Hu
- Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences; Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Jinsong Zheng
- Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences; Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Wuhan Xiao
- Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences; Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Yujiang Hao
- Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences; Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Wenhua Liu
- Marine Biology Institute, Shantou University, Shantou, Guangdong 515063, China
| | - Ding Wang
- Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences; Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
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Tamma G, Goswami N, Reichmuth J, De Santo NG, Valenti G. Aquaporins, vasopressin, and aging: current perspectives. Endocrinology 2015; 156:777-88. [PMID: 25514088 DOI: 10.1210/en.2014-1812] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Functioning of the hypothalamic-neurohypophyseal-vasopressin axis is altered in aging, and the pathway may represent a plausible target to slow the process of aging. Arginine vasopressin, a nine-amino acid peptide that is secreted from the posterior pituitary in response to high plasma osmolality and hypotension, is central in this pathway. Vasopressin has important roles in circulatory and water homoeostasis mediated by vasopressin receptor subtypes V1a (vascular), V1b (pituitary), and V2 (vascular, renal). A dysfunction in this pathway as a result of aging can result in multiple abnormalities in several physiological systems. In addition, vasopressin plasma concentration is significantly higher in males than in females and vasopressin-mediated effects on renal and vascular targets are more pronounced in males than in females. These findings may be caused by sex differences in vasopressin secretion and action, making men more susceptible than females to diseases like hypertension, cardiovascular and chronic kidney diseases, and urolithiasis. Recently the availability of new, potent, orally active vasopressin receptor antagonists, the vaptans, has strongly increased the interest on vasopressin and its receptors as a new target for prevention of age-related diseases associated with its receptor-altered signaling. This review summarizes the recent literature in the field of vasopressin signaling in age-dependent abnormalities in kidney, cardiovascular function, and bone function.
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Affiliation(s)
- Grazia Tamma
- Department of Biosciences, Biotechnologies, and Biopharmaceutics (G.T., G.V.), University of Bari, 70125 Bari, Italy; Istituto Nazionale di Biostrutture e Biosistemi (G.T., G.V.), 00136 Roma, Italy; Gravitational Physiology and Medicine Research Unit (N.G., J.R.), Institute of Physiology, Medical University of Graz, 8036 Graz, Austria; Department of Medicine (N.G.D.S.), Second University of Naples, 80138 Naples, Italy; and Centro di Eccellenza di Genomica (G.V.) Campo Biomedico Ed Agrario, University of Bari, 70126 Bari, Italy
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Lee S, Esteva-Font C, Phuan PW, Anderson MO, Verkman AS. Discovery, synthesis and structure-activity analysis of symmetrical 2,7-disubstituted fluorenones as urea transporter inhibitors. MEDCHEMCOMM 2015; 6:1278-1284. [PMID: 26191399 DOI: 10.1039/c5md00198f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Kidney urea transporters are targets for development of small-molecule inhibitors with action as salt-sparing diuretics. A cell-based, functional high-throughput screen identified 2,7-bisacetamido fluorenone 3 as a novel inhibitor of urea transporters UT-A1 and UT-B. Here, we synthesized twenty-two 2,7-disubstituted fluorenone analogs by acylation. Structure-activity relationship analysis revealed: (a) the carbonyl moiety at C9 is required for UT inhibition; (b) steric limitation on C2, 7-substituents; and (c) the importance of a crescent-shape structure. The most potent fluorenones inhibited UT-A1 and UT-B urea transport with IC50 ~ 1 μM. Analysis of in vitro metabolic stability in hepatic microsomes indicated metabolism of 2,7-disubstituted fluorenones by reductase and subsequent elimination. Computational docking to a homology model of UT-A1 suggested UT inhibitor binding to the UT cytoplasmic domain at a site that does not overlap with the putative urea binding site.
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Affiliation(s)
- Sujin Lee
- Departments of Medicine and Physiology, University of California, San Francisco CA, 94143-0521 USA
| | - Cristina Esteva-Font
- Departments of Medicine and Physiology, University of California, San Francisco CA, 94143-0521 USA
| | - Puay-Wah Phuan
- Departments of Medicine and Physiology, University of California, San Francisco CA, 94143-0521 USA
| | - Marc O Anderson
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco CA, 94132-4136 USA
| | - A S Verkman
- Departments of Medicine and Physiology, University of California, San Francisco CA, 94143-0521 USA
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43
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Hyodo S, Kakumura K, Takagi W, Hasegawa K, Yamaguchi Y. Morphological and functional characteristics of the kidney of cartilaginous fishes: with special reference to urea reabsorption. Am J Physiol Regul Integr Comp Physiol 2014; 307:R1381-95. [PMID: 25339681 DOI: 10.1152/ajpregu.00033.2014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
For adaptation to high-salinity marine environments, cartilaginous fishes (sharks, skates, rays, and chimaeras) adopt a unique urea-based osmoregulation strategy. Their kidneys reabsorb nearly all filtered urea from the primary urine, and this is an essential component of urea retention in their body fluid. Anatomical investigations have revealed the extraordinarily elaborate nephron system in the kidney of cartilaginous fishes, e.g., the four-loop configuration of each nephron, the occurrence of distinct sinus and bundle zones, and the sac-like peritubular sheath in the bundle zone, in which the nephron segments are arranged in a countercurrent fashion. These anatomical and morphological characteristics have been considered to be important for urea reabsorption; however, a mechanism for urea reabsorption is still largely unknown. This review focuses on recent progress in the identification and mapping of various pumps, channels, and transporters on the nephron segments in the kidney of cartilaginous fishes. The molecules include urea transporters, Na(+)/K(+)-ATPase, Na(+)-K(+)-Cl(-) cotransporters, and aquaporins, which most probably all contribute to the urea reabsorption process. Although research is still in progress, a possible model for urea reabsorption in the kidney of cartilaginous fishes is discussed based on the anatomical features of nephron segments and vascular systems and on the results of molecular mapping. The molecular anatomical approach thus provides a powerful tool for understanding the physiological processes that take place in the highly elaborate kidney of cartilaginous fishes.
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Affiliation(s)
- Susumu Hyodo
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, Kawshiwa, Chiba, Japan
| | - Keigo Kakumura
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, Kawshiwa, Chiba, Japan
| | - Wataru Takagi
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, Kawshiwa, Chiba, Japan
| | - Kumi Hasegawa
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, Kawshiwa, Chiba, Japan
| | - Yoko Yamaguchi
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, Kawshiwa, Chiba, Japan
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Ren H, Wang Y, Xing Y, Ran J, Liu M, Lei T, Zhou H, Li R, Sands JM, Yang B. Thienoquinolins exert diuresis by strongly inhibiting UT-A urea transporters. Am J Physiol Renal Physiol 2014; 307:F1363-72. [PMID: 25298523 DOI: 10.1152/ajprenal.00421.2014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Urea transporters (UT) play an important role in the urine concentration mechanism by mediating intrarenal urea recycling, suggesting that UT inhibitors could have therapeutic use as a novel class of diuretic. Recently, we found a thienoquinolin UT inhibitor, PU-14, that exhibited diuretic activity. The purpose of this study was to identify more potent UT inhibitors that strongly inhibit UT-A isoforms in the inner medullary collecting duct (IMCD). Efficient thienoquinolin UT inhibitors were identified by structure-activity relationship analysis. Urea transport inhibition activity was assayed in perfused rat terminal IMCDs. Diuretic activity of the compound was determined in rats and mice using metabolic cages. The results show that the compound PU-48 exhibited potent UT-A inhibition activity. The inhibition was 69.5% with an IC50 of 0.32 μM. PU-48 significantly inhibited urea transport in perfused rat terminal IMCDs. PU-48 caused significant diuresis in UT-B null mice, which indicates that UT-A is the target of PU-48. The diuresis caused by PU-48 did not change blood Na(+), K(+), or Cl(-) levels or nonurea solute excretion in rats and mice. No toxicity was detected in cells or animals treated with PU-48. The results indicate that thienoquinolin UT inhibitors induce a diuresis by inhibiting UT-A in the IMCD. This suggests that they may have the potential to be developed as a novel class of diuretics with fewer side effects than classical diuretics.
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Affiliation(s)
- Huiwen Ren
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Yanhua Wang
- Renal Division, Departments of Medicine and Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Yongning Xing
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Jianhua Ran
- Department of Anatomy, Neuroscience Research Center, Basic Medical College, Chongqing Medical University, Chongqing, China; and
| | - Ming Liu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Tianluo Lei
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Hong Zhou
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Runtao Li
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Jeff M Sands
- Renal Division, Departments of Medicine and Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Baoxue Yang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China; Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China
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45
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Abstract
A urea transporter protein in the kidney was first proposed in 1987. The first urea transporter cDNA was cloned in 1993. The SLC14a urea transporter family contains two major subgroups: SLC14a1, the UT-B urea transporter originally isolated from erythrocytes; and SLC14a2, the UT-A group originally isolated from kidney inner medulla. Slc14a1, the human UT-B gene, arises from a single locus located on chromosome 18q12.1-q21.1, which is located close to Slc14a2. Slc14a1 includes 11 exons, with the coding region extending from exon 4 to exon 11, and is approximately 30 kb in length. The Slc14a2 gene is a very large gene with 24 exons, is approximately 300 kb in length, and encodes 6 different isoforms. Slc14a2 contains two promoter elements: promoter I is located in the typical position, upstream of exon 1, and drives the transcription of UT-A1, UT-A1b, UT-A3, UT-A3b, and UT-A4; while promoter II is located within intron 12 and drives the transcription of UT-A2 and UT-A2b. UT-A1 and UT-A3 are located in the inner medullary collecting duct, UT-A2 in the thin descending limb and liver, UT-A5 in testis, UT-A6 in colon, UT-B1 primarily in descending vasa recta and erythrocytes, and UT-B2 in rumen.
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Affiliation(s)
- Jeff M Sands
- Renal Division, Department of Medicine and Department of Physiology, Emory University School of Medicine, WMB Room 338, 1639 Pierce Drive, NE, Atlanta, GA, 30322, USA,
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46
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Abstract
Members of the urea transporter (UT) family mediate rapid, selective transport of urea down its concentration gradient. To date, crystal structures of two evolutionarily distant UTs have been solved. These structures reveal a common UT fold involving two structurally homologous domains that encircle a continuous membrane-spanning pore and indicate that UTs transport urea via a channel-like mechanism. Examination of the conserved architecture of the pore, combined with crystal structures of ligand-bound proteins, molecular dynamics simulations, and functional data on permeation and inhibition by a broad range of urea analogs and other small molecules, provides insight into the structural basis of urea permeation and selectivity.
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Affiliation(s)
- Elena J. Levin
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine 1 Baylor Plaza, Houston, TX 77030 USA
| | - Ming Zhou
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine 1 Baylor Plaza, Houston, TX 77030 USA
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47
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Abstract
UT-A and UT-B families of urea transporters consist of multiple isoforms that are subject to regulation of both acutely and by long-term measures. This chapter provides a brief overview of the expression of the urea transporter forms and their locations in the kidney. Rapid regulation of UT-A1 results from the combination of phosphorylation and membrane accumulation. Phosphorylation of UT-A1 has been linked to vasopressin and hyperosmolality, although through different kinases. Other acute influences on urea transporter activity are ubiquitination and glycosylation, both of which influence the membrane association of the urea transporter, again through different mechanisms. Long-term regulation of urea transport is most closely associated with the environment that the kidney experiences. Low-protein diets may influence the amount of urea transporter available. Conditions of osmotic diuresis, where urea concentrations are low, will prompt an increase in urea transporter abundance. Although adrenal steroids affect urea transporter abundance, conflicting reports make conclusions tenuous. Urea transporters are upregulated when P2Y2 purinergic receptors are decreased, suggesting a role for these receptors in UT regulation. Hypercalcemia and hypokalemia both cause urine concentration deficiencies. Urea transporter abundances are reduced in aging animals and animals with angiotensin-converting enzyme deficiencies. This chapter will provide information about both rapid and long-term regulation of urea transporters and provide an introduction into the literature.
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Affiliation(s)
- Janet D Klein
- Renal Division, Department of Medicine and Department of Physiology, Emory University School of Medicine, WMB Room 3319B, 1639 Pierce Drive, NE, Atlanta, GA, 30322, USA,
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48
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Abstract
A selective urea transporter UT-A1 inhibitor would be a novel type of diuretic, likely with less undesirable side effects than conventional diuretics, because it acts on the last portion of the nephron. In this issue of Chemistry & Biology, Esteva-Font and colleagues develop such an inhibitor by using a clever high-throughput screening assay and document its selectivity.
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Affiliation(s)
- Jeff M Sands
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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49
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Sands JM. Urine concentrating and diluting ability during aging. J Gerontol A Biol Sci Med Sci 2012; 67:1352-7. [PMID: 22588950 PMCID: PMC3670161 DOI: 10.1093/gerona/gls128] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 04/06/2012] [Indexed: 11/13/2022] Open
Abstract
Urine concentrating ability is reduced during normal aging in people and rats. The abundance of many of the key transport proteins that contribute to urine concentrating ability is reduced in the kidney medulla of aged rats. The reductions in water, sodium, and urea transport protein abundances, and their reduced response to water restriction, contribute to the reduced ability of aged rats to concentrate their urine and conserve water. If similar mechanisms occur in human kidneys, it would provide a molecular explanation for the reduced urine concentrating ability in aging and may provide opportunities for novel therapeutic approaches to improve urine concentrating ability and/or nocturnal polyuria.
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Affiliation(s)
- Jeff M Sands
- Renal Division, Department of Medicine, Emory University School of Medicine, WMRB Room 338, NE, 1639 Pierce Drive, Atlanta, GA 30322, USA.
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50
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Klein JD, Blount MA, Sands JM. Molecular mechanisms of urea transport in health and disease. Pflugers Arch 2012; 464:561-72. [PMID: 23007461 PMCID: PMC3514661 DOI: 10.1007/s00424-012-1157-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 09/05/2012] [Accepted: 09/06/2012] [Indexed: 10/27/2022]
Abstract
In the late 1980s, urea permeability measurements produced values that could not be explained by paracellular transport or lipid phase diffusion. The existence of urea transport proteins were thus proposed and less than a decade later, the first urea transporter was cloned. The family of urea transporters has two major subgroups, designated SLC14A1 (or UT-B) and Slc14A2 (or UT-A). UT-B and UT-A gene products are glycoproteins located in various extra-renal tissues however, a majority of the resulting isoforms are found in the kidney. The UT-B (Slc14A1) urea transporter was originally isolated from erythrocytes and two isoforms have been reported. In kidney, UT-B is located primarily in the descending vasa recta. The UT-A (Slc14A2) urea transporter yields six distinct isoforms, of which three are found chiefly in the kidney medulla. UT-A1 and UT-A3 are found in the inner medullary collecting duct (IMCD), while UT-A2 is located in the thin descending limb. These transporters are crucial to the kidney's ability to concentrate urine. The regulation of urea transporter activity in the IMCD involves acute modification through phosphorylation and subsequent movement to the plasma membrane. UT-A1 and UT-A3 accumulate in the plasma membrane in response to stimulation by vasopressin or hypertonicity. Long-term regulation of the urea transporters in the IMCD involves altering protein abundance in response to changes in hydration status, low protein diets, or adrenal steroids. Urea transporters have been studied using animal models of disease including diabetes mellitus, lithium intoxication, hypertension, and nephrotoxic drug responses. Exciting new genetically engineered mouse models are being developed to study these transporters.
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Affiliation(s)
- Janet D Klein
- Renal Division, Department of Medicine, and Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
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