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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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Han Z, Ma K, Tao H, Liu H, Zhang J, Sai X, Li Y, Chi M, Nian Q, Song L, Liu C. A Deep Insight Into Regulatory T Cell Metabolism in Renal Disease: Facts and Perspectives. Front Immunol 2022; 13:826732. [PMID: 35251009 PMCID: PMC8892604 DOI: 10.3389/fimmu.2022.826732] [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: 12/01/2021] [Accepted: 01/24/2022] [Indexed: 11/29/2022] Open
Abstract
Kidney disease encompasses a complex set of diseases that can aggravate or start systemic pathophysiological processes through their complex metabolic mechanisms and effects on body homoeostasis. The prevalence of kidney disease has increased dramatically over the last two decades. CD4+CD25+ regulatory T (Treg) cells that express the transcription factor forkhead box protein 3 (Foxp3) are critical for maintaining immune homeostasis and preventing autoimmune disease and tissue damage caused by excessive or unnecessary immune activation, including autoimmune kidney diseases. Recent studies have highlighted the critical role of metabolic reprogramming in controlling the plasticity, stability, and function of Treg cells. They are also likely to play a vital role in limiting kidney transplant rejection and potentially promoting transplant tolerance. Metabolic pathways, such as mitochondrial function, glycolysis, lipid synthesis, glutaminolysis, and mammalian target of rapamycin (mTOR) activation, are involved in the development of renal diseases by modulating the function and proliferation of Treg cells. Targeting metabolic pathways to alter Treg cells can offer a promising method for renal disease therapy. In this review, we provide a new perspective on the role of Treg cell metabolism in renal diseases by presenting the renal microenvironment、relevant metabolites of Treg cell metabolism, and the role of Treg cell metabolism in various kidney diseases.
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Affiliation(s)
- Zhongyu Han
- Department of Nephrology, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital, Sichuan Renal Disease Clinical Research Center, University of Electronic Science and Technology of China, Chengdu, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China.,Reproductive & Women-Children Hospital, School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Kuai Ma
- Department of Nephrology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Hongxia Tao
- Reproductive & Women-Children Hospital, School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Hongli Liu
- Reproductive & Women-Children Hospital, School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jiong Zhang
- Department of Nephrology, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital, Sichuan Renal Disease Clinical Research Center, University of Electronic Science and Technology of China, Chengdu, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| | - Xiyalatu Sai
- Affiliated Hospital of Inner Mongolia University for the Nationalities, Tongliao, China
| | - Yunlong Li
- Reproductive & Women-Children Hospital, School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Mingxuan Chi
- Department of Nephrology, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital, Sichuan Renal Disease Clinical Research Center, University of Electronic Science and Technology of China, Chengdu, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| | - Qing Nian
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China.,Department of Blood Transfusion Sicuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Linjiang Song
- Reproductive & Women-Children Hospital, School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Chi Liu
- Department of Nephrology, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital, Sichuan Renal Disease Clinical Research Center, University of Electronic Science and Technology of China, Chengdu, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
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Komrakova M, Blaschke M, Ponce ML, Klüver A, Köpp R, Hüfner M, Schieker M, Miosge N, Siggelkow H. Decreased Expression of the Human Urea Transporter SLC14A1 in Bone is Induced by Cytokines and Stimulates Adipogenesis of Mesenchymal Progenitor Cells. Exp Clin Endocrinol Diabetes 2020; 128:582-595. [PMID: 31958845 DOI: 10.1055/a-1084-3888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The human urea transporter SLC14A1 (HUT11/UT-B) has been suggested as a marker for the adipogenic differentiation of bone cells with a relevance for bone diseases. We investigated the function of SLC14A1 in different cells models from bone environment. SLC14A1 expression and cytokine production was investigated in bone cells obtained from patients with osteoporosis. Gene and protein expression of SLC14A1 was studied during adipogenic or osteogenic differentiation of human mesenchymal progenitor cells (hMSCs) and of the single-cell-derived hMSC line (SCP-1), as well as in osteoclasts and chondrocytes. Localization was determined by histochemical methods and functionality by urea transport experiments. Expression of SLC14A1 mRNA was lower in cells from patients with osteoporosis that produced high levels of cytokines. Accordingly, when adding a combination of cytokines to SCP-1 SLC14A1 mRNA expression decreased. SLC14A1 mRNA expression decreased after both osteogenic and more pronounced adipogenic stimulation of hMSCs and SCP-1 cells. The highest SLC14A1 expression was determined in undifferentiated cells, lowest in chondrocytes and osteoclasts. Downregulation of SLC14A1 by siRNA resulted in an increased expression of interleukin-6 and interleukin-1 beta as well as adipogenic markers. Urea influx through SLC14A1 increased expression of osteogenic markers, adipogenic markers were suppressed. SLC14A1 protein was localized in the cell membrane and the cytoplasm. Summarizing, the SLC14A1 urea transporter affects early differentiation of hMSCs by diminishing osteogenesis or by favoring adipogenesis, depending on its expression level. Therefore, SLC14A1 is not unequivocally an adipogenic marker in bone. Our findings suggest an involvement of SLC14A1 in bone metabolism and inflammatory processes and disease-dependent influences on its expression.
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Affiliation(s)
- Marina Komrakova
- Clinic of Gastroenterology and Gastrointestinal Oncology, University Medical Center Göttingen, Göttingen, Germany
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Göttingen, Göttingen, Germany
| | - Martina Blaschke
- Clinic of Gastroenterology and Gastrointestinal Oncology, University Medical Center Göttingen, Göttingen, Germany
- Endokrinologikum Göttingen, Göttingen, Germany
| | - Maria Laura Ponce
- Clinic of Gastroenterology and Gastrointestinal Oncology, University Medical Center Göttingen, Göttingen, Germany
| | - Anne Klüver
- Clinic of Gastroenterology and Gastrointestinal Oncology, University Medical Center Göttingen, Göttingen, Germany
| | - Regine Köpp
- Clinic of Gastroenterology and Gastrointestinal Oncology, University Medical Center Göttingen, Göttingen, Germany
| | | | - Matthias Schieker
- Experimental Surgery and Regenerative Medicine, Department of Surgery, Ludwig-Maximillians-University (LMU), Munich, Germany
| | - Nicolai Miosge
- Bone tissue regeneration work group, University Medical Center Göttingen, Göttingen, Germany
| | - Heide Siggelkow
- Clinic of Gastroenterology and Gastrointestinal Oncology, University Medical Center Göttingen, Göttingen, Germany
- Endokrinologikum Göttingen, Göttingen, Germany
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Geng X, Zhang S, He J, Ma A, Li Y, Li M, Zhou H, Chen G, Yang B. The urea transporter UT-A1 plays a predominant role in a urea-dependent urine-concentrating mechanism. J Biol Chem 2020; 295:9893-9900. [PMID: 32461256 PMCID: PMC7380188 DOI: 10.1074/jbc.ra120.013628] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/22/2020] [Indexed: 12/12/2022] Open
Abstract
Urea transporters are a family of urea-selective channel proteins expressed in multiple tissues that play an important role in the urine-concentrating mechanism of the mammalian kidney. Previous studies have shown that knockout of urea transporter (UT)-B, UT-A1/A3, or all UTs leads to urea-selective diuresis, indicating that urea transporters have important roles in urine concentration. Here, we sought to determine the role of UT-A1 in the urine-concentrating mechanism in a newly developed UT-A1-knockout mouse model. Phenotypically, daily urine output in UT-A1-knockout mice was nearly 3-fold that of WT mice and 82% of all-UT-knockout mice, and the UT-A1-knockout mice had significantly lower urine osmolality than WT mice. After 24-h water restriction, acute urea loading, or high-protein (40%) intake, UT-A1-knockout mice were unable to increase urine-concentrating ability. Compared with all-UT-knockout mice, the UT-A1-knockout mice exhibited similarly elevated daily urine output and decreased urine osmolality, indicating impaired urea-selective urine concentration. Our experimental findings reveal that UT-A1 has a predominant role in urea-dependent urine-concentrating mechanisms, suggesting that UT-A1 represents a promising diuretic target.
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Affiliation(s)
- Xiaoqiang Geng
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Shun Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Jinzhao He
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Ang Ma
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Yingjie Li
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Min Li
- 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
| | - Guangping Chen
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - 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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5
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Yu L, Liu T, Fu S, Li L, Meng X, Su X, Xie Z, Ren J, Meng Y, Lv X, Du Y. Physiological functions of urea transporter B. Pflugers Arch 2019; 471:1359-1368. [PMID: 31734718 PMCID: PMC6882768 DOI: 10.1007/s00424-019-02323-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 10/16/2019] [Accepted: 10/17/2019] [Indexed: 11/04/2022]
Abstract
Urea transporters (UTs) are membrane proteins in the urea transporter protein A (UT-A) and urea transporter protein B (UT-B) families. UT-B is mainly expressed in endothelial cell membrane of the renal medulla and in other tissues, including the brain, heart, pancreas, colon, bladder, bone marrow, and cochlea. UT-B is responsible for the maintenance of urea concentration, male reproductive function, blood pressure, bone metabolism, and brain astrocyte and cardiac functions. Its deficiency and dysfunction contribute to the pathogenesis of many diseases. Actually, UT-B deficiency increases the sensitivity of bladder epithelial cells to apoptosis triggers in mice and UT-B-null mice develop II-III atrioventricular block and depression. The expression of UT-B in the rumen of cow and sheep may participate in digestive function. However, there is no systemic review to discuss the UT-B functions. Here, we update research approaches to understanding the functions of UT-B.
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Affiliation(s)
- Lanying Yu
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Tiantian Liu
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Shuang Fu
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Li Li
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Xiaoping Meng
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Xin Su
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Zhanfeng Xie
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Jiayan Ren
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Yan Meng
- Department of Pathophysiology, College of Basic Medicine, Jilin University, Changchun, 130021, Jilin, People's Republic of China.
| | - Xuejiao Lv
- Department of Respiratory Medicine, the Second Affiliated Hospital of Jilin University, Changchun, 130041, Jilin, People's Republic of China.
| | - Yanwei Du
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China.
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Pharmacokinetics, Tissue Distribution and Excretion of a Novel Diuretic (PU-48) in Rats. Pharmaceutics 2018; 10:pharmaceutics10030124. [PMID: 30096833 PMCID: PMC6160999 DOI: 10.3390/pharmaceutics10030124] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 07/21/2018] [Accepted: 07/27/2018] [Indexed: 01/02/2023] Open
Abstract
Methyl 3-amino-6-methoxythieno [2,3-b] quinoline-2-carboxylate (PU-48) is a novel diuretic urea transporter inhibitor. The aim of this study is to investigate the profile of plasma pharmacokinetics, tissue distribution, and excretion by oral dosing of PU-48 in rats. Concentrations of PU-48 within biological samples are determined using a validated high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. After oral administration of PU-48 (3, 6, and 12 mg/kg, respectively) in self-nanomicroemulsifying drug delivery system (SNEDDS) formulation, the peak plasma concentrations (Cmax), and the area under the curve (AUC0⁻∞) were increased by the dose-dependent and linear manner, but the marked different of plasma half-life (t1/2) were not observed. This suggests that the pharmacokinetic profile of PU-48 prototype was first-order elimination kinetic characteristics within the oral three doses range in rat plasma. Moreover, the prototype of PU-48 was rapidly and extensively distributed into thirteen tissues, especially higher concentrations were detected in stomach, intestine, liver, kidney, and bladder. The total accumulative excretion of PU-48 in the urine, feces, and bile was less than 2%. This research is the first report on disposition via oral administration of PU-48 in rats, and it provides important information for further development of PU-48 as a diuretic drug candidate.
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Zhang ZY, Wang X, Liu D, Zhang H, Zhang Q, Lu YY, Li P, Lou YQ, Yang BX, Lu C, Lou YX, Zhang GL. Development and validation of an LC-MS/MS method for the determination of a novel thienoquinolin urea transporter inhibitor PU-48 in rat plasma and its application to a pharmacokinetic study. Biomed Chromatogr 2018; 32. [PMID: 29193233 DOI: 10.1002/bmc.4157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 10/05/2017] [Accepted: 11/20/2017] [Indexed: 01/25/2023]
Abstract
A specific, sensitive and stable high-performance liquid chromatographic-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantitative determination of methyl 3-amino-6-methoxythieno [2,3-b]quinoline-2-carboxylate (PU-48), a novel diuretic thienoquinolin urea transporter inhibitor in rat plasma. In this method, the chromatographic separation of PU-48 was achieved with a reversed-phase C18 column (100 × 2.1 mm, 3 μm) at 35°C. The mobile phase consisted of acetonitrile and water with 0.05% formic acid added with a gradient elution at flow rate of 0.3 mL/min. Samples were detected with the triple-quadrupole tandem mass spectrometer with multiple reaction monitoring mode via electrospray ionization source in positive mode. The retention time were 6.2 min for PU-48 and 7.2 min for megestrol acetate (internal standard, IS). The monitored ion transitions were mass-to-charge ratio (m/z) 289.1 → 229.2 for PU-48 and m/z 385.3 → 267.1 for the internal standard. The calibration curve for PU-48 was linear over the concentration range of 0.1-1000 ng/mL (r2 > 0.99), and the lower limit of quantitation was 0.1 ng/mL. The precision, accuracy and stability of the method were validated adequately. The developed and validated method was successfully applied to the pharmacokinetic study of PU-48 in rats.
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Affiliation(s)
- Zhi-Yuan Zhang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Xin Wang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Dan Liu
- Proteomics Laboratory, Medical and Health Analysis Center, Peking University, Beijing, China
| | - Hua Zhang
- Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Qiang Zhang
- Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Ying-Yuan Lu
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Pu Li
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Ya-Qing Lou
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Bao-Xue Yang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Chuang Lu
- Department of Drug Metabolism and Pharmacokinetics, Biogen, Cambridge, Massachusetts, USA
| | - Ya-Xin Lou
- Proteomics Laboratory, Medical and Health Analysis Center, Peking University, Beijing, China
| | - Guo-Liang Zhang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
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Ganoderma triterpenes retard renal cyst development by downregulating Ras/MAPK signaling and promoting cell differentiation. Kidney Int 2017; 92:1404-1418. [PMID: 28709639 DOI: 10.1016/j.kint.2017.04.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 04/08/2017] [Accepted: 04/13/2017] [Indexed: 01/02/2023]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is a common monogenetic disease characterized by the progressive development of renal cysts with further need for effective therapy. Here our aim was to investigate the effect of Ganoderma triterpenes (GT) on the development of kidney cysts. Importantly, GT attenuated cyst development in two mouse models of ADPKD with phenotypes of severe cystic kidney disease. Assays for tubulogenesis showed that GT promoted epithelial tubule formation in MDCK cells, suggesting a possible effect on epithelial cell differentiation. The role of GT in regulating key signaling pathways involved in the pathogenesis of PKD was further investigated by immune blotting. This showed that GT specifically downregulated the activation of the Ras/MAPK signaling pathway both in vitro and in vivo without detectable effect on the mTOR pathway. This mechanism may be involved in GT downregulating intracellular cAMP levels. Screening of 15 monomers purified from GT for their effects on cyst development indicated that CBLZ-7 (ethyl ganoderate C2) had a potent inhibitory effect on cyst development in vitro. Additionally, like GT, CBLZ-7 was able to downregulate forskolin-induced activation of the Ras/MAPK pathway. Thus, GT and its purified monomer CBLZ-7 may be potential therapeutic regents for treating ADPKD.
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Jiang T, Li Y, Layton AT, Wang W, Sun Y, Li M, Zhou H, Yang B. Generation and phenotypic analysis of mice lacking all urea transporters. Kidney Int 2017; 91:338-351. [PMID: 27914708 PMCID: PMC5423716 DOI: 10.1016/j.kint.2016.09.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/30/2016] [Accepted: 09/08/2016] [Indexed: 01/22/2023]
Abstract
Urea transporters (UT) are a family of transmembrane urea-selective channel proteins expressed in multiple tissues and play an important role in the urine concentrating mechanism of the mammalian kidney. UT inhibitors have diuretic activity and could be developed as novel diuretics. To determine if functional deficiency of all UTs in all tissues causes physiological abnormality, we established a novel mouse model in which all UTs were knocked out by deleting an 87 kb of DNA fragment containing most parts of Slc14a1 and Slc14a2 genes. Western blot analysis and immunofluorescence confirmed that there is no expression of urea transporter in these all-UT-knockout mice. Daily urine output was nearly 3.5-fold higher, with significantly lower urine osmolality in all-UT-knockout mice than that in wild-type mice. All-UT-knockout mice were not able to increase urinary urea concentration and osmolality after water deprivation, acute urea loading, or high protein intake. A computational model that simulated UT-knockout mouse models identified the individual contribution of each UT in urine concentrating mechanism. Knocking out all UTs also decreased the blood pressure and promoted the maturation of the male reproductive system. Thus, functional deficiency of all UTs caused a urea-selective urine-concentrating defect with little physiological abnormality in extrarenal organs.
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Affiliation(s)
- Tao Jiang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Yingjie Li
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Anita T Layton
- Department of Mathematics, Duke University, Durham, North Carolina, USA
| | - Weiling Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Yi Sun
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Min Li
- 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
| | - 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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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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