1
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Daskivich GJ, Brodsky JL. The generation of detergent-insoluble clipped fragments from an ERAD substrate in mammalian cells. Sci Rep 2023; 13:21508. [PMID: 38057493 PMCID: PMC10700608 DOI: 10.1038/s41598-023-48769-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/30/2023] [Indexed: 12/08/2023] Open
Abstract
Proteostasis ensures the proper synthesis, folding, and trafficking of proteins and is required for cellular and organellar homeostasis. This network also oversees protein quality control within the cell and prevents accumulation of aberrant proteins, which can lead to cellular dysfunction and disease. For example, protein aggregates irreversibly disrupt proteostasis and can exert gain-of-function toxic effects. Although this process has been examined in detail for cytosolic proteins, how endoplasmic reticulum (ER)-tethered, aggregation-prone proteins are handled is ill-defined. To determine how a membrane protein with a cytoplasmic aggregation-prone domain is routed for ER-associated degradation (ERAD), we analyzed a new model substrate, TM-Ubc9ts. In yeast, we previously showed that TM-Ubc9ts ERAD requires Hsp104, which is absent in higher cells. In transient and stable HEK293 cells, we now report that TM-Ubc9ts degradation is largely proteasome-dependent, especially at elevated temperatures. In contrast to yeast, clipped TM-Ubc9ts polypeptides, which are stabilized upon proteasome inhibition, accumulate and are insoluble at elevated temperatures. TM-Ubc9ts cleavage is independent of the intramembrane protease RHBDL4, which clips other classes of ERAD substrates. These studies highlight an unappreciated mechanism underlying the degradation of aggregation-prone substrates in the ER and invite further work on other proteases that contribute to ERAD.
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Affiliation(s)
- Grant J Daskivich
- A320 Langley Hall, Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Jeffrey L Brodsky
- A320 Langley Hall, Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
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2
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Hagströmer CJ, Hyld Steffen J, Kreida S, Al-Jubair T, Frick A, Gourdon P, Törnroth-Horsefield S. Structural and functional analysis of aquaporin-2 mutants involved in nephrogenic diabetes insipidus. Sci Rep 2023; 13:14674. [PMID: 37674034 PMCID: PMC10482962 DOI: 10.1038/s41598-023-41616-1] [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: 03/14/2023] [Accepted: 08/29/2023] [Indexed: 09/08/2023] Open
Abstract
Aquaporins are water channels found in the cell membrane, where they allow the passage of water molecules in and out of the cells. In the kidney collecting duct, arginine vasopressin-dependent trafficking of aquaporin-2 (AQP2) fine-tunes reabsorption of water from pre-urine, allowing precise regulation of the final urine volume. Point mutations in the gene for AQP2 may disturb this process and lead to nephrogenic diabetes insipidus (NDI), whereby patients void large volumes of highly hypo-osmotic urine. In recessive NDI, mutants of AQP2 are retained in the endoplasmic reticulum due to misfolding. Here we describe the structural and functional characterization of three AQP2 mutations associated with recessive NDI: T125M and T126M, situated close to a glycosylation site and A147T in the transmembrane region. Using a proteoliposome assay, we show that all three mutants permit the transport of water. The crystal structures of T125M and T126M together with biophysical characterization of all three mutants support that they retain the native structure, but that there is a significant destabilization of A147T. Our work provides unique molecular insights into the mechanisms behind recessive NDI as well as deepens our understanding of how misfolded proteins are recognized by the ER quality control system.
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Affiliation(s)
| | - Jonas Hyld Steffen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Stefan Kreida
- Department of Biochemistry and Structural Biology, Lund University, Lund, Sweden
| | - Tamim Al-Jubair
- Department of Biochemistry and Structural Biology, Lund University, Lund, Sweden
| | - Anna Frick
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Pontus Gourdon
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Experimental Medical Science, Lund University, Lund, Sweden
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3
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Qiu Z, Jiang T, Li Y, Wang W, Yang B. Aquaporins in Urinary System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1398:155-177. [PMID: 36717493 DOI: 10.1007/978-981-19-7415-1_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
There are at least eight aquaporins (AQPs) expressed in the kidney. Including AQP1 expressed in proximal tubules, thin descending limb of Henle and vasa recta; AQP2, AQP3, AQP4, AQP5, and AQP6 expressed in collecting ducts; AQP7 expressed in proximal tubules; AQP8 expressed in proximal tubules and collecting ducts; and AQP11 expressed in the endoplasmic reticulum of proximal tubular epithelial cells. Over years, researchers have constructed different AQP knockout mice and explored the effect of AQP knockout on kidney function. Thus, the roles of AQPs in renal physiology are revealed, providing very useful information for addressing fundamental questions about transepithelial water transport and the mechanism of near isoosmolar fluid reabsorption. This chapter introduces the localization and function of AQPs in the kidney and their roles in different kidney diseases to reveal the prospects of AQPs in further basic and clinical studies.
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Affiliation(s)
- Zhiwei Qiu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Tao Jiang
- College of Basic Medicine, Beihua University, Jilin, China
| | - Yingjie Li
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Weiling Wang
- Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, P.R. China
| | - Baoxue Yang
- School of Basic Medical Sciences, Peking University, Beijing, China.
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4
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Hoffiz YC, Castillo-Ruiz A, Hall MAL, Hite TA, Gray JM, Cisternas CD, Cortes LR, Jacobs AJ, Forger NG. Birth elicits a conserved neuroendocrine response with implications for perinatal osmoregulation and neuronal cell death. Sci Rep 2021; 11:2335. [PMID: 33504846 PMCID: PMC7840942 DOI: 10.1038/s41598-021-81511-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 01/05/2021] [Indexed: 12/17/2022] Open
Abstract
Long-standing clinical findings report a dramatic surge of vasopressin in umbilical cord blood of the human neonate, but the neural underpinnings and function(s) of this phenomenon remain obscure. We studied neural activation in perinatal mice and rats, and found that birth triggers activation of the suprachiasmatic, supraoptic, and paraventricular nuclei of the hypothalamus. This was seen whether mice were born vaginally or via Cesarean section (C-section), and when birth timing was experimentally manipulated. Neuronal phenotyping showed that the activated neurons were predominantly vasopressinergic, and vasopressin mRNA increased fivefold in the hypothalamus during the 2–3 days before birth. Copeptin, a surrogate marker of vasopressin, was elevated 30-to 50-fold in plasma of perinatal mice, with higher levels after a vaginal than a C-section birth. We also found an acute decrease in plasma osmolality after a vaginal, but not C-section birth, suggesting that the difference in vasopressin release between birth modes is functionally meaningful. When vasopressin was administered centrally to newborns, we found an ~ 50% reduction in neuronal cell death in specific brain areas. Collectively, our results identify a conserved neuroendocrine response to birth that is sensitive to birth mode, and influences peripheral physiology and neurodevelopment.
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Affiliation(s)
- Yarely C Hoffiz
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, USA
| | | | - Megan A L Hall
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, USA
| | - Taylor A Hite
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, USA
| | - Jennifer M Gray
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, USA
| | - Carla D Cisternas
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, USA.,Instituto de Investigación Médica M Y M Ferreyra, INIMEC-CONICET-UNC, Córdoba, Argentina
| | - Laura R Cortes
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, USA
| | - Andrew J Jacobs
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, USA
| | - Nancy G Forger
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, USA.
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5
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Xue J, Thomas L, Dominguez Rieg JA, Fenton RA, Rieg T. Genetic deletion of connexin 37 causes polyuria and polydipsia. PLoS One 2020; 15:e0244251. [PMID: 33332450 PMCID: PMC7746157 DOI: 10.1371/journal.pone.0244251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/07/2020] [Indexed: 11/19/2022] Open
Abstract
The connexin 37 (Cx37) channel is clustered at gap junctions between cells in the renal vasculature or the renal tubule where it is abundant in basolateral cell interdigitations and infoldings of epithelial cells in the proximal tubule, thick ascending limb, distal convoluted tubule and collecting duct; however, physiological data regarding its role are limited. In this study, we investigated the role of Cx37 in fluid homeostasis using mice with a global deletion of Cx37 (Cx37-/- mice). Under baseline conditions, Cx37-/- had ~40% higher fluid intake associated with ~40% lower urine osmolality compared to wild-type (WT) mice. No differences were observed between genotypes in urinary adenosine triphosphate or prostaglandin E2, paracrine factors that alter renal water handling. After 18-hours of water deprivation, plasma aldosterone and urine osmolality increased significantly in Cx37-/- and WT mice; however, the latter remained ~375 mmol/kg lower in Cx37-/- mice, an effect associated with a more pronounced body weight loss despite higher urinary AVP/creatinine ratios compared to WT mice. Consistent with this, fluid intake in the first 3 hours after water deprivation was 37% greater in Cx37-/- vs WT mice. Cx37-/- mice showed significantly lower renal AQP2 abundance and AQP2 phosphorylation at serine 256 than WT mice in response to vehicle or dDAVP, suggesting a partial contribution of the kidney to the lower urine osmolality. The abundance and responses of the vasopressin V2 receptor, AQP3, NHE3, NKCC2, NCC, H+-ATPase, αENaC, γENaC or Na+/K+-ATPase were not significantly different between genotypes. In summary, these results demonstrate that Cx37 is important for body water handling.
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Affiliation(s)
- Jianxiang Xue
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Linto Thomas
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Jessica A. Dominguez Rieg
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | | | - Timo Rieg
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
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6
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Xing G, Jing H, Zhang L, Cao Y, Li L, Zhao K, Dong Z, Chen W, Wang H, Cao R, Xiong WC, Mei L. A mechanism in agrin signaling revealed by a prevalent Rapsyn mutation in congenital myasthenic syndrome. eLife 2019; 8:e49180. [PMID: 31549961 PMCID: PMC6779466 DOI: 10.7554/elife.49180] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 09/23/2019] [Indexed: 12/15/2022] Open
Abstract
Neuromuscular junction is a synapse between motoneurons and skeletal muscles, where acetylcholine receptors (AChRs) are concentrated to control muscle contraction. Studies of this synapse have contributed to our understanding of synapse assembly and pathological mechanisms of neuromuscular disorders. Nevertheless, underlying mechanisms of NMJ formation was not well understood. To this end, we took a novel approach - studying mutant genes implicated in congenital myasthenic syndrome (CMS). We showed that knock-in mice carrying N88K, a prevalent CMS mutation of Rapsyn (Rapsn), died soon after birth with profound NMJ deficits. Rapsn is an adapter protein that bridges AChRs to the cytoskeleton and possesses E3 ligase activity. In investigating how N88K impairs the NMJ, we uncovered a novel signaling pathway by which Agrin-LRP4-MuSK induces tyrosine phosphorylation of Rapsn, which is required for its self-association and E3 ligase activity. Our results also provide insight into pathological mechanisms of CMS.
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Affiliation(s)
- Guanglin Xing
- Department of Neurosciences, School of MedicineCase Western Reserve UniversityClevelandUnited States
| | - Hongyang Jing
- Department of Neurosciences, School of MedicineCase Western Reserve UniversityClevelandUnited States
| | - Lei Zhang
- Department of Neurosciences, School of MedicineCase Western Reserve UniversityClevelandUnited States
| | - Yu Cao
- Department of Neuroscience and Regenerative MedicineAugusta UniversityAugustaUnited States
| | - Lei Li
- Department of Neurosciences, School of MedicineCase Western Reserve UniversityClevelandUnited States
| | - Kai Zhao
- Department of Neurosciences, School of MedicineCase Western Reserve UniversityClevelandUnited States
- Department of Neuroscience and Regenerative MedicineAugusta UniversityAugustaUnited States
| | - Zhaoqi Dong
- Department of Neurosciences, School of MedicineCase Western Reserve UniversityClevelandUnited States
| | - Wenbing Chen
- Department of Neurosciences, School of MedicineCase Western Reserve UniversityClevelandUnited States
| | - Hongsheng Wang
- Department of Neurosciences, School of MedicineCase Western Reserve UniversityClevelandUnited States
| | - Rangjuan Cao
- Department of Neurosciences, School of MedicineCase Western Reserve UniversityClevelandUnited States
| | - Wen-Cheng Xiong
- Department of Neurosciences, School of MedicineCase Western Reserve UniversityClevelandUnited States
- Louis Stokes Cleveland Veterans Affairs Medical CenterClevelandUnited States
| | - Lin Mei
- Department of Neurosciences, School of MedicineCase Western Reserve UniversityClevelandUnited States
- Louis Stokes Cleveland Veterans Affairs Medical CenterClevelandUnited States
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7
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Lashhab R, Ullah AS, Cordat E. Renal collecting duct physiology and pathophysiology. Biochem Cell Biol 2019; 97:234-242. [DOI: 10.1139/bcb-2018-0192] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Rawad Lashhab
- Department of Physiology and Membrane Protein and Disease Research Group, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Physiology and Membrane Protein and Disease Research Group, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - A.K.M. Shahid Ullah
- Department of Physiology and Membrane Protein and Disease Research Group, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Physiology and Membrane Protein and Disease Research Group, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Emmanuelle Cordat
- Department of Physiology and Membrane Protein and Disease Research Group, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Physiology and Membrane Protein and Disease Research Group, University of Alberta, Edmonton, AB T6G 2H7, Canada
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8
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Aquaporins in Renal Diseases. Int J Mol Sci 2019; 20:ijms20020366. [PMID: 30654539 PMCID: PMC6359174 DOI: 10.3390/ijms20020366] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 12/16/2022] Open
Abstract
Aquaporins (AQPs) are a family of highly selective transmembrane channels that mainly transport water across the cell and some facilitate low-molecular-weight solutes. Eight AQPs, including AQP1, AQP2, AQP3, AQP4, AQP5, AQP6, AQP7, and AQP11, are expressed in different segments and various cells in the kidney to maintain normal urine concentration function. AQP2 is critical in regulating urine concentrating ability. The expression and function of AQP2 are regulated by a series of transcriptional factors and post-transcriptional phosphorylation, ubiquitination, and glycosylation. Mutation or functional deficiency of AQP2 leads to severe nephrogenic diabetes insipidus. Studies with animal models show AQPs are related to acute kidney injury and various chronic kidney diseases, such as diabetic nephropathy, polycystic kidney disease, and renal cell carcinoma. Experimental data suggest ideal prospects for AQPs as biomarkers and therapeutic targets in clinic. This review article mainly focuses on recent advances in studying AQPs in renal diseases.
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9
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Jain S, Chen F. Developmental pathology of congenital kidney and urinary tract anomalies. Clin Kidney J 2018; 12:382-399. [PMID: 31198539 PMCID: PMC6543978 DOI: 10.1093/ckj/sfy112] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Indexed: 12/18/2022] Open
Abstract
Congenital anomalies of the kidneys or lower urinary tract (CAKUT) are the most common causes of renal failure in children and account for 25% of end-stage renal disease in adults. The spectrum of anomalies includes renal agenesis; hypoplasia; dysplasia; supernumerary, ectopic or fused kidneys; duplication; ureteropelvic junction obstruction; primary megaureter or ureterovesical junction obstruction; vesicoureteral reflux; ureterocele; and posterior urethral valves. CAKUT originates from developmental defects and can occur in isolation or as part of other syndromes. In recent decades, along with better understanding of the pathological features of the human congenital urinary tract defects, researchers using animal models have provided valuable insights into the pathogenesis of these diseases. However, the genetic causes and etiology of many CAKUT cases remain unknown, presenting challenges in finding effective treatment. Here we provide an overview of the critical steps of normal development of the urinary system, followed by a description of the pathological features of major types of CAKUT with respect to developmental mechanisms of their etiology.
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Affiliation(s)
- Sanjay Jain
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St Louis, MO, USA
| | - Feng Chen
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St Louis, MO, USA
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10
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Ding YP, Yu HS, Wang JL, Shao BP. Immunoexpression of aquaporins 1, 2, 3 and 4 in kidney of yak (Bos grunniens) on the Qinghai-Tibetan Plateau. Biotech Histochem 2018; 94:48-52. [PMID: 30328721 DOI: 10.1080/10520295.2018.1495843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Aquaporins (AQP) 1, 2, 3 and 4 belong to the aquaporin water channel family and play an important role in urine concentration by reabsorption of water from renal tubule fluid. Renal AQPs have not been reported in the yak (Bos grunniens), which resides in the Qinghai Tibetan Plateau. We investigated AQPs 1-4 expressions in the kidneys of Yak using immunohistochemical staining. AQP1 was expressed mainly in the basolateral and apical membranes of the proximal tubules and descending thin limb of the loop of Henle. AQP2 was detected in the apical plasma membranes of collecting ducts and distal convoluted tubules. AQP3 was located in the proximal tubule, distal tubule and collecting ducts. AQP4 was located in the collecting ducts, distal straight tubule, glomerular capillaries and peritubular capillaries. The expression pattern of AQPs 1-4 in kidney of yak was different from other species, which possibly is related to kidney function in a high altitude environment.
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Affiliation(s)
- Y P Ding
- a School of life Science , Northwest Normal University , Lanzhou , P. R.China
| | - H S Yu
- b School of Life Science , Lanzhou University , Lanzhou , P. R. China
| | - J L Wang
- b School of Life Science , Lanzhou University , Lanzhou , P. R. China
| | - B P Shao
- b School of Life Science , Lanzhou University , Lanzhou , P. R. China
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11
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Zhao M, Yang Y, Guo Z, Shao C, Sun H, Zhang Y, Sun Y, Liu Y, Song Y, Zhang L, Li Q, Liu J, Li M, Gao Y, Sun W. A Comparative Proteomics Analysis of Five Body Fluids: Plasma, Urine, Cerebrospinal Fluid, Amniotic Fluid, and Saliva. Proteomics Clin Appl 2018; 12:e1800008. [PMID: 29781159 DOI: 10.1002/prca.201800008] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 05/05/2018] [Indexed: 01/05/2023]
Abstract
PURPOSE Body fluid is considered a rich source of disease biomarkers. Proteins in many body fluids have potential clinical applications for disease diagnostic and prognostic predictions. EXPERIMENTAL DESIGN To determine differences in the protein components and functional features of body fluids, a proteomic comparison of five body fluids (plasma, urine, cerebrospinal fluid, saliva, and amniotic fluid) was conducted by high-resolution mass spectrometry. RESULTS A total of 4717 nonredundant proteins were identified, and the concentrations of 3433 proteins were estimated by an intensity-based algorithm quantitation method. Among them, 564 proteins were shared among the five body fluids, with common functions in the coagulation/prothrombin system and inflammatory response. A total of 36.7% of the proteins were detected in only one body fluid and were closely related to their adjacent tissues by function. The functional analysis of the remaining 2986 proteins showed that similar functions might be shared among different body fluids, which highlighted intimate connection in the body. CONCLUSIONS AND CLINICAL RELEVANCE The quantitative comparative functional analysis indicated that body fluids might reflect the diverse functions of the whole body rather than the characteristics of their adjacent tissues. The above data might indicate the potential application of body fluids for biomarker discovery.
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Affiliation(s)
- Mindi Zhao
- Department of Pathology and Pathophysiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China.,Department of Laboratory Medicine, Beijing Hospital, National Center of Gerontology, Beijing, 100730, China
| | - Yehong Yang
- Core Facility of Instrument, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Zhengguang Guo
- Core Facility of Instrument, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Chen Shao
- Center for Bioinformatics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Haidan Sun
- Core Facility of Instrument, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Yang Zhang
- Department of Neurosurgery, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100050, China
| | - Ying Sun
- Department of Nephrology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Yaoran Liu
- Department of Stomatology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Yijun Song
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Liwei Zhang
- Department of Neurosurgery, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100050, China
| | - Qian Li
- Department of Stomatology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Juntao Liu
- Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Mingxi Li
- Department of Nephrology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Youhe Gao
- Department of Biochemistry and Molecular Biology, Gene Engineering and Biotechnology Beijing Key Laboratory, Beijing Normal University, Beijing, 100875, China
| | - Wei Sun
- Core Facility of Instrument, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
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12
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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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Milano S, Carmosino M, Gerbino A, Svelto M, Procino G. Hereditary Nephrogenic Diabetes Insipidus: Pathophysiology and Possible Treatment. An Update. Int J Mol Sci 2017; 18:ijms18112385. [PMID: 29125546 PMCID: PMC5713354 DOI: 10.3390/ijms18112385] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/03/2017] [Accepted: 11/07/2017] [Indexed: 12/17/2022] Open
Abstract
Under physiological conditions, excessive loss of water through the urine is prevented by the release of the antidiuretic hormone arginine-vasopressin (AVP) from the posterior pituitary. In the kidney, AVP elicits a number of cellular responses, which converge on increasing the osmotic reabsorption of water in the collecting duct. One of the key events triggered by the binding of AVP to its type-2 receptor (AVPR2) is the exocytosis of the water channel aquaporin 2 (AQP2) at the apical membrane the principal cells of the collecting duct. Mutations of either AVPR2 or AQP2 result in a genetic disease known as nephrogenic diabetes insipidus, which is characterized by the lack of responsiveness of the collecting duct to the antidiuretic action of AVP. The affected subject, being incapable of concentrating the urine, presents marked polyuria and compensatory polydipsia and is constantly at risk of severe dehydration. The molecular bases of the disease are fully uncovered, as well as the genetic or clinical tests for a prompt diagnosis of the disease in newborns. A real cure for nephrogenic diabetes insipidus (NDI) is still missing, and the main symptoms of the disease are handled with s continuous supply of water, a restrictive diet, and nonspecific drugs. Unfortunately, the current therapeutic options are limited and only partially beneficial. Further investigation in vitro or using the available animal models of the disease, combined with clinical trials, will eventually lead to the identification of one or more targeted strategies that will improve or replace the current conventional therapy and grant NDI patients a better quality of life. Here we provide an updated overview of the genetic defects causing NDI, the most recent strategies under investigation for rescuing the activity of mutated AVPR2 or AQP2, or for bypassing defective AVPR2 signaling and restoring AQP2 plasma membrane expression.
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Affiliation(s)
- Serena Milano
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, 70126 Bari, Italy.
| | - Monica Carmosino
- Department of Sciences, University of Basilicata, 85100 Potenza, Italy.
| | - Andrea Gerbino
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, 70126 Bari, Italy.
| | - Maria Svelto
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, 70126 Bari, Italy.
| | - Giuseppe Procino
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, 70126 Bari, Italy.
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Chang Z, Zhang H, Wu X, Nabi F, Rehman MU, Yuan X, Mehmood K, Zhou D. Renal Dose Dopamine Mediates the Level of Aquaporin-2 Water Channel (Aqp2) in Broiler Chickens. BRAZILIAN JOURNAL OF POULTRY SCIENCE 2017. [DOI: 10.1590/1806-9061-2016-0406] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Z Chang
- Huazhong Agricultural University, China
| | - H Zhang
- Huazhong Agricultural University, China
| | - X Wu
- Huazhong Agricultural University, China
| | - F Nabi
- Huazhong Agricultural University, China
| | - MU Rehman
- Huazhong Agricultural University, China
| | - X Yuan
- Huazhong Agricultural University, China
| | - K Mehmood
- Huazhong Agricultural University, China; Islamia University of Bahawalpur, Pakistan
| | - D Zhou
- Huazhong Agricultural University, China
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15
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Chen L, Higgins PJ, Zhang W. Development and Diseases of the Collecting Duct System. Results Probl Cell Differ 2017; 60:165-203. [PMID: 28409346 DOI: 10.1007/978-3-319-51436-9_7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The collecting duct of the mammalian kidney is important for the regulation of extracellular volume, osmolarity, and pH. There are two major structurally and functionally distinct cell types: principal cells and intercalated cells. The former regulates Na+ and water homeostasis, while the latter participates in acid-base homeostasis. In vivo lineage tracing using Cre recombinase or its derivatives such as CreGFP and CreERT2 is a powerful new technique to identify stem/progenitor cells in their native environment and to decipher the origins of the tissue that they give rise to. Recent studies using this technique in mice have revealed multiple renal progenitor cell populations that differentiate into various nephron segments and collecting duct. In particular, emerging evidence suggests that like principal cells, most of intercalated cells originate from the progenitor cells expressing water channel Aquaporin 2. Mutations or malfunctions of the channels, pumps, and transporters expressed in the collecting duct system cause various human diseases. For example, gain-of-function mutations in ENaC cause Liddle's syndrome, while loss-of-function mutations in ENaC lead to Pseudohypoaldosteronism type 1. Mutations in either AE1 or V-ATPase B1 result in distal renal tubular acidosis. Patients with disrupted AQP2 or AVPR2 develop nephrogenic diabetes insipidus. A better understanding of the function and development of the collecting duct system may facilitate the discovery of new therapeutic strategies for treating kidney disease.
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Affiliation(s)
- Lihe Chen
- Epithelial Systems Biology Laboratory, Systems Biology Center, NHLBI, Bethesda, MD, 20892-1603, USA
| | - Paul J Higgins
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, MC-165, 47 New Scotland Avenue, Albany, NY, 12208, USA
| | - Wenzheng Zhang
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, MC-165, 47 New Scotland Avenue, Albany, NY, 12208, USA.
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16
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Li Y, Wang W, Jiang T, Yang B. Aquaporins in Urinary System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 969:131-148. [PMID: 28258571 DOI: 10.1007/978-94-024-1057-0_9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Several aquaporin (AQP )-type water channels are expressed in kidney: AQP1 in the proximal tubule, thin descending limb of Henle, and vasa recta; AQP2 -6 in the collecting duct; AQP7 in the proximal tubule; AQP8 in the proximal tubule and collecting duct; and AQP11 in the endoplasmic reticulum of proximal tubule cells. AQP2 is the vasopressin-regulated water channel that is important in hereditary and acquired diseases affecting urine-concentrating ability. The roles of AQPs in renal physiology and transepithelial water transport have been determined using AQP knockout mouse models. This chapter describes renal physiologic insights revealed by phenotypic analysis of AQP knockout mice and the prospects for further basic and clinical studies.
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Affiliation(s)
- Yingjie Li
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Weiling Wang
- State Key Laboratory of Natural and Biomimetic Drugs, and Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Tao Jiang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Baoxue Yang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, 100191, China.
- State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, 100191, China.
- Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing, 100191, China.
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17
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Baturina GS, Katkova LE, Zarogiannis SG, Solenov EI. Brattleboro rats have impaired apical membrane water permeability regulation in the outer medullary collecting duct principal cells. Clin Exp Pharmacol Physiol 2016; 43:1225-1233. [DOI: 10.1111/1440-1681.12666] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 07/28/2016] [Accepted: 08/31/2016] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Sotirios G Zarogiannis
- Department of Physiology; Faculty of Medicine; University of Thessaly; BIOPOLIS; Larissa Greece
| | - Evgeniy I Solenov
- Institute of Cytology and Genetics, SB RAS; Novosibirsk Russia
- Novosibirsk State University; Novosibirsk Russia
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18
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Vukićević T, Schulz M, Faust D, Klussmann E. The Trafficking of the Water Channel Aquaporin-2 in Renal Principal Cells-a Potential Target for Pharmacological Intervention in Cardiovascular Diseases. Front Pharmacol 2016; 7:23. [PMID: 26903868 PMCID: PMC4749865 DOI: 10.3389/fphar.2016.00023] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 01/25/2016] [Indexed: 01/13/2023] Open
Abstract
Arginine-vasopressin (AVP) stimulates the redistribution of water channels, aquaporin-2 (AQP2) from intracellular vesicles into the plasma membrane of renal collecting duct principal cells. By this AVP directs 10% of the water reabsorption from the 170 L of primary urine that the human kidneys produce each day. This review discusses molecular mechanisms underlying the AVP-induced redistribution of AQP2; in particular, it provides an overview over the proteins participating in the control of its localization. Defects preventing the insertion of AQP2 into the plasma membrane cause diabetes insipidus. The disease can be acquired or inherited, and is characterized by polyuria and polydipsia. Vice versa, up-regulation of the system causing a predominant localization of AQP2 in the plasma membrane leads to excessive water retention and hyponatremia as in the syndrome of inappropriate antidiuretic hormone secretion (SIADH), late stage heart failure or liver cirrhosis. This article briefly summarizes the currently available pharmacotherapies for the treatment of such water balance disorders, and discusses the value of newly identified mechanisms controlling AQP2 for developing novel pharmacological strategies. Innovative concepts for the therapy of water balance disorders are required as there is a medical need due to the lack of causal treatments.
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Affiliation(s)
- Tanja Vukićević
- Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Association Berlin, Germany
| | - Maike Schulz
- Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Association Berlin, Germany
| | - Dörte Faust
- Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Association Berlin, Germany
| | - Enno Klussmann
- Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz AssociationBerlin, Germany; German Centre for Cardiovascular ResearchBerlin, Germany
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19
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Beitz E, Golldack A, Rothert M, von Bülow J. Challenges and achievements in the therapeutic modulation of aquaporin functionality. Pharmacol Ther 2015; 155:22-35. [PMID: 26277280 DOI: 10.1016/j.pharmthera.2015.08.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Aquaporin (AQP) water and solute channels have basic physiological functions throughout the human body. AQP-facilitated water permeability across cell membranes is required for rapid reabsorption of water from pre-urine in the kidneys and for sustained near isosmolar water fluxes e.g. in the brain, eyes, inner ear, and lungs. Cellular water permeability is further connected to cell motility. AQPs of the aquaglyceroporin subfamily are necessary for lipid degradation in adipocytes and glycerol uptake into the liver, as well as for skin moistening. Modulation of AQP function is desirable in several pathophysiological situations, such as nephrogenic diabetes insipidus, Sjögren's syndrome, Menière's disease, heart failure, or tumors to name a few. Attempts to design or to find effective small molecule AQP inhibitors have yielded only a few hits. Challenges reside in the high copy number of AQP proteins in the cell membranes, and spatial restrictions in the protein structure. This review gives an overview on selected physiological and pathophysiological conditions in which modulation of AQP functions appears beneficial and discusses first achievements in the search of drug-like AQP inhibitors.
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Affiliation(s)
- Eric Beitz
- Pharmaceutical and Medicinal Chemistry, University of Kiel, Germany.
| | - André Golldack
- Pharmaceutical and Medicinal Chemistry, University of Kiel, Germany
| | - Monja Rothert
- Pharmaceutical and Medicinal Chemistry, University of Kiel, Germany
| | - Julia von Bülow
- Pharmaceutical and Medicinal Chemistry, University of Kiel, Germany
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20
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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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21
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Yu J. miRNAs in mammalian ureteric bud development. Pediatr Nephrol 2014; 29:745-9. [PMID: 24452329 DOI: 10.1007/s00467-013-2734-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 12/06/2013] [Accepted: 12/12/2013] [Indexed: 12/20/2022]
Abstract
The collecting duct network and the urothelium of the ureter of the metanephric kidney are derived from the ureteric bud epithelium, initially an outgrowth from the caudal end of the Wolffian duct at the onset of the metanephric kidney development. The tips of the ureteric bud epithelium undergo reiterative branching morphogenesis, which generates more tips and trunks, whereas the ureteric trunks grow and differentiate into principal cells and intercalated cells of the collecting ducts that regulate body water and acid-base homeostasis. microRNAs (miRNAs) are a family of small non-coding RNAs that regulate a diversity of biological processes including organogenesis, mostly by negatively regulating their target gene expression. In this review, I will summarize the current knowledge on the critical roles of miRNAs expressed in the ureteric bud epithelium in ureteric bud morphogenesis and differentiation, including ureteric bud branching morphogenesis, collecting duct terminal differentiation, cystogenesis of the collecting ducts, and ureter development.
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Affiliation(s)
- Jing Yu
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA,
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22
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Abstract
The aquaporins (AQPs) are a family of small, integral membrane proteins that facilitate water transport across the plasma membranes of cells in response to osmotic gradients. Data from knockout mice support the involvement of AQPs in epithelial fluid secretion, cell migration, brain oedema and adipocyte metabolism, which suggests that modulation of AQP function or expression could have therapeutic potential in oedema, cancer, obesity, brain injury, glaucoma and several other conditions. Moreover, loss-of-function mutations in human AQPs cause congenital cataracts (AQP0) and nephrogenic diabetes insipidus (AQP2), and autoantibodies against AQP4 cause the autoimmune demyelinating disease neuromyelitis optica. Although some potential AQP modulators have been identified, challenges associated with the development of better modulators include the druggability of the target and the suitability of the assay methods used to identify modulators.
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23
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Luo Y, Liu Y, Liu M, Wei J, Zhang Y, Hou J, Huang W, Wang T, Li X, He Y, Ding F, Yuan L, Cai J, Zheng F, Yang JY. Sfmbt2 10th intron-hosted miR-466(a/e)-3p are important epigenetic regulators of Nfat5 signaling, osmoregulation and urine concentration in mice. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:97-106. [PMID: 24389345 DOI: 10.1016/j.bbagrm.2013.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 12/13/2013] [Accepted: 12/18/2013] [Indexed: 10/25/2022]
Abstract
Sfmbt2-hosted miR-466a-3p and its close relatives are often among the most significantly up-regulated or down-regulated miRNAs in responses to numerous deleterious environmental stimuli. The exact roles of these miRNAs in cellular stress responses, however, are not clear. Here we showed that many Sfmbt2-hosted miRNAs were highly hypertonic stress responsive in vitro and in vivo. In renal medulla, water deprivation induced alterations in the expression of miR-466(a/b/c/e/p)-3p in a pattern similar to that of miR-200b-3p, a known regulator of osmoresponsive transcription factor Nfat5. Remarkably, exposure of mIMCD3 cells to an arginine vasopressin analog time-dependently down-regulated the expression of miR-466(a/b/c/e/p)-3p and miR-200b-3p, which provides a novel regulatory mechanism for these osmoresponsive miRNAs. In cultured mIMCD3 cells we further demonstrated that miR-466a-3p and miR-466g were capable of targeting Nfat5 by interacting with its 3'UTR. In transgenic mice overexpressing miR-466a-3p, significant down-regulation of Nfat5 and many other osmoregulation-related genes was observed in both the renal cortex and medulla. Moreover, sustained transgenic over-expression of miR-466a-3p was found to be associated with polydipsia, polyuria and disturbed ion homeostasis and kidney morphology. Since the mature sequence of miR-466a-3p is completely equivalent to that of miR-466e-3p and that the seed sequence of miR-466a-3p is completely equivalent to that of miR-297(a/b/c)-3p, miR-466d-3p, miR-467g and miR-669d-3p, and that miR-466a-3p differs from miR-466(b/c/p)-3p only in a 5' nucleotide, we propose that miR-466a-3p and many of its close relatives are important epigenetic regulators of renal Nfat5 signaling, osmoregulation and urine concentration in mice.
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Affiliation(s)
- Yu Luo
- School of Nursing, The Third Military Medical University, Chongqing 400038, China; State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen 361102, China
| | - Ying Liu
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen 361102, China
| | - Meng Liu
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen 361102, China
| | - Jie Wei
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen 361102, China
| | - Yunyun Zhang
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen 361102, China
| | - Jinpao Hou
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen 361102, China
| | - Weifeng Huang
- The First Affiliated Hospital of Xiamen University, Xiamen 361005, China
| | - Tao Wang
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen 361102, China
| | - Xun Li
- The First Affiliated Hospital of Xiamen University, Xiamen 361005, China
| | - Ying He
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen 361102, China; Fujian Provincial Transgenic Core, Xiamen University Laboratory Animal Center, Xiang'an, Xiamen 361102, China
| | - Feng Ding
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen 361102, China; Fujian Provincial Transgenic Core, Xiamen University Laboratory Animal Center, Xiang'an, Xiamen 361102, China
| | - Li Yuan
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen 361102, China
| | - Jianchun Cai
- Zhongshan Hospital, Xiamen University, Xiamen 361005, China
| | - Feng Zheng
- Department of Nephrology and Basic Science Laboratory, Union Hospital, Fujian Medical University, Fuzhou 350001, China
| | - James Y Yang
- School of Nursing, The Third Military Medical University, Chongqing 400038, China; Fujian Provincial Transgenic Core, Xiamen University Laboratory Animal Center, Xiang'an, Xiamen 361102, China.
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Abstract
Aquaporins (AQPs) are a family of membrane water channels that basically function as regulators of intracellular and intercellular water flow. To date, thirteen aquaporins have been characterized. They are distributed wildly in specific cell types in multiple organs and tissues. Each AQP channel consists of six membrane-spanning alpha-helices that have a central water-transporting pore. Four AQP monomers assemble to form tetramers, which are the functional units in the membrane. Some of AQPs also transport urea, glycerol, ammonia, hydrogen peroxide, and gas molecules. AQP-mediated osmotic water transport across epithelial plasma membranes facilitates transcellular fluid transport and thus water reabsorption. AQP-mediated urea and glycerol transport is involved in energy metabolism and epidermal hydration. AQP-mediated CO2 and NH3 transport across membrane maintains intracellular acid-base homeostasis. AQPs are also involved in the pathophysiology of a wide range of human diseases (including water disbalance in kidney and brain, neuroinflammatory disease, obesity, and cancer). Further work is required to determine whether aquaporins are viable therapeutic targets or reliable diagnostic and prognostic biomarkers.
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25
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Kortenoeven MLA, Fenton RA. Renal aquaporins and water balance disorders. Biochim Biophys Acta Gen Subj 2013; 1840:1533-49. [PMID: 24342488 DOI: 10.1016/j.bbagen.2013.12.002] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 11/26/2013] [Accepted: 12/09/2013] [Indexed: 12/17/2022]
Abstract
BACKGROUND Aquaporins (AQPs) are a family of proteins that can act as water channels. Regulation of AQPs is critical to osmoregulation and the maintenance of body water homeostasis. Eight AQPs are expressed in the kidney of which five have been shown to play a role in body water balance; AQP1, AQP2, AQP3, AQP4 and AQP7. AQP2 in particular is regulated by vasopressin. SCOPE OF REVIEW This review summarizes our current knowledge of the underlying mechanisms of various water balance disorders and their treatment strategies. MAJOR CONCLUSIONS Dysfunctions of AQPs are involved in disorders associated with disturbed water homeostasis. Hyponatremia with increased AQP levels can be caused by diseases with low effective circulating blood volume, such as congestive heart failure, or osmoregulation disorders such as the syndrome of inappropriate secretion of antidiuretic hormone. Treatment consists of fluid restriction, demeclocycline and vasopressin type-2 receptor antagonists. Decreased AQP levels can lead to diabetes insipidus (DI), characterized by polyuria and polydipsia. In central DI, vasopressin production is impaired, while in gestational DI, levels of the vasopressin-degrading enzyme vasopressinase are abnormally increased. Treatment consists of the vasopressin analogue dDAVP. Nephrogenic DI is caused by the inability of the kidney to respond to vasopressin and can be congenital, but is most commonly acquired, usually due to lithium therapy. Treatment consists of sufficient fluid supply, low-solute diet and diuretics. GENERAL SIGNIFICANCE In recent years, our understanding of the underlying mechanisms of water balance disorders has increased enormously, which has opened up several possible new treatment strategies. This article is part of a Special Issue entitled Aquaporins.
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Affiliation(s)
- Marleen L A Kortenoeven
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Center for Interactions of Proteins in Epithelial Transport (InterPrET), Aarhus University, Aarhus, Denmark.
| | - Robert A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Center for Interactions of Proteins in Epithelial Transport (InterPrET), Aarhus University, Aarhus, Denmark.
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Schmidt K, Ripper M, Tegtmeier I, Humberg E, Sterner C, Reichold M, Warth R, Bandulik S. Dynamics of Renal Electrolyte Excretion in Growing Mice. ACTA ACUST UNITED AC 2013; 124:7-13. [DOI: 10.1159/000356816] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 10/25/2013] [Indexed: 11/19/2022]
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27
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Dynamic regulation and dysregulation of the water channel aquaporin-2: a common cause of and promising therapeutic target for water balance disorders. Clin Exp Nephrol 2013; 18:558-70. [DOI: 10.1007/s10157-013-0878-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 09/24/2013] [Indexed: 12/11/2022]
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28
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Moeller HB, Rittig S, Fenton RA. Nephrogenic diabetes insipidus: essential insights into the molecular background and potential therapies for treatment. Endocr Rev 2013; 34:278-301. [PMID: 23360744 PMCID: PMC3610677 DOI: 10.1210/er.2012-1044] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The water channel aquaporin-2 (AQP2), expressed in the kidney collecting ducts, plays a pivotal role in maintaining body water balance. The channel is regulated by the peptide hormone arginine vasopressin (AVP), which exerts its effects through the type 2 vasopressin receptor (AVPR2). Disrupted function or regulation of AQP2 or the AVPR2 results in nephrogenic diabetes insipidus (NDI), a common clinical condition of renal origin characterized by polydipsia and polyuria. Over several years, major research efforts have advanced our understanding of NDI at the genetic, cellular, molecular, and biological levels. NDI is commonly characterized as hereditary (congenital) NDI, arising from genetic mutations in the AVPR2 or AQP2; or acquired NDI, due to for exmple medical treatment or electrolyte disturbances. In this article, we provide a comprehensive overview of the genetic, cell biological, and pathophysiological causes of NDI, with emphasis on the congenital forms and the acquired forms arising from lithium and other drug therapies, acute and chronic renal failure, and disturbed levels of calcium and potassium. Additionally, we provide an overview of the exciting new treatment strategies that have been recently proposed for alleviating the symptoms of some forms of the disease and for bypassing G protein-coupled receptor signaling.
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Affiliation(s)
- Hanne B Moeller
- Department of Biomedicine, Aarhus University, and Department of Pediatrics, Aarhus University Hospital, Wilhelm Meyers Alle 3, Building 1234, Aarhus 8000, Denmark.
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Kortenoeven MLA, Pedersen NB, Miller RL, Rojek A, Fenton RA. Genetic ablation of aquaporin-2 in the mouse connecting tubules results in defective renal water handling. J Physiol 2013; 591:2205-19. [PMID: 23359673 DOI: 10.1113/jphysiol.2012.250852] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Body water balance is regulated via the water channel aquaporin-2 (AQP2), which is expressed in the renal connecting tubule (CNT) and collecting duct (CD). The relative roles of AQP2 in the CNT and CD are not fully understood. To study the role of AQP2 in the CNT we generated a mouse model with CNT-specific AQP2 deletion (AQP2-CNT-knockout (KO)). Confocal laser scanning microscopy and immunogold electron microscopy demonstrated an absence of AQP2 in the CNT of AQP2-CNT-KO mice. Twenty-four hour urine output was significantly increased (KO: 3.0 ± 0.3 ml (20 g body weight (BW))(-1); wild-type (WT): 1.9 ± 0.3 ml (20 g BW)(-1)) and urine osmolality decreased (KO: 1179 ± 107 mosmol kg(-1); WT: 1790 ± 146 mosmol kg(-1)) in AQP2-CNT-KO mice compared with controls. After 24 h water restriction, urine osmolality was still significantly lower in AQP2-CNT-KO mice (KO: 2087 ± 169 mosmol kg(-1); WT: 2678 ± 144 mosmol kg(-1)). A significant difference in urine osmolality between groups before desmopressin (dDAVP) (KO: 873 ± 129 mosmol kg(-1); WT: 1387 ± 163 mosmol kg(-1)) was not apparent 2 h after injection, with urine osmolality increased significantly in both groups (KO: 2944 ± 41 mosmol kg(-1); WT: 3133 ± 66 mosmol kg(-1)). Cortical kidney fractions from AQP2-CNT-KO mice had significantly reduced AQP2, with no compensatory changes in sodium potassium chloride cotransporter (NKCC2), AQP3 or AQP4. Lithium chloride treatment increased urine volume and decreased osmolality in both WT and AQP2-CNT-KO mice. After 8 days of treatment, the AQP2-CNT-KO mice still had a significantly higher urine volume and lower urine osmolality, suggesting that the CNT does not play a significant role in the pathology of lithium-induced nephrogenic diabetes insipidus. Our studies indicate that the CNT plays a role in regulating body water balance under basal conditions, but not for maximal concentration of the urine during antidiuresis.
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Congenital nephrogenic diabetes insipidus: the current state of affairs. Pediatr Nephrol 2012; 27:2183-204. [PMID: 22427315 DOI: 10.1007/s00467-012-2118-8] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 01/14/2012] [Accepted: 01/17/2012] [Indexed: 01/02/2023]
Abstract
The anti-diuretic hormone arginine vasopressin (AVP) is released from the pituitary upon hypovolemia or hypernatremia, and regulates water reabsorption in the renal collecting duct principal cells. Binding of AVP to the arginine vasopressin receptor type 2 (AVPR2) in the basolateral membrane leads to translocation of aquaporin 2 (AQP2) water channels to the apical membrane of the collecting duct principal cells, inducing water permeability of the membrane. This results in water reabsorption from the pro-urine into the medullary interstitium following an osmotic gradient. Congenital nephrogenic diabetes insipidus (NDI) is a disorder associated with mutations in either the AVPR2 or AQP2 gene, causing the inability of patients to concentrate their pro-urine, which leads to a high risk of dehydration. This review focuses on the current knowledge regarding the cell biological aspects of congenital X-linked, autosomal-recessive and autosomal-dominant NDI while specifically addressing the latest developments in the field. Based on deepened mechanistic understanding, new therapeutic strategies are currently being explored, which we also discuss here.
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Chen Y, Rice W, Gu Z, Li J, Huang J, Brenner MB, Van Hoek A, Xiong J, Gundersen GG, Norman JC, Hsu VW, Fenton RA, Brown D, Lu HAJ. Aquaporin 2 promotes cell migration and epithelial morphogenesis. J Am Soc Nephrol 2012; 23:1506-17. [PMID: 22859853 DOI: 10.1681/asn.2012010079] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The aquaporin 2 (AQP2) water channel, expressed in kidney collecting ducts, contributes critically to water homeostasis in mammals. Animals lacking or having significantly reduced levels of AQP2, however, have not only urinary concentrating abnormalities but also renal tubular defects that lead to neonatal mortality from renal failure. Here, we show that AQP2 is not only a water channel but also an integrin-binding membrane protein that promotes cell migration and epithelial morphogenesis. AQP2 expression modulates the trafficking and internalization of integrin β1, facilitating its turnover at focal adhesions. In vitro, disturbing the interaction between AQP2 and integrin β1 by mutating the RGD motif led to reduced endocytosis, retention of integrin β1 at the cell surface, and defective cell migration and tubulogenesis. Similarly, in vivo, AQP2-null mice exhibited significant retention of integrin β1 at the basolateral membrane and had tubular abnormalities. In summary, these data suggest that the water channel AQP2 interacts with integrins to promote renal epithelial cell migration, contributing to the structural and functional integrity of the mammalian kidney.
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Affiliation(s)
- Ying Chen
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Simches Research Center, 185 Cambridge Street, Boston, MA 02114, USA
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Tamma G, Procino G, Svelto M, Valenti G. Cell culture models and animal models for studying the patho-physiological role of renal aquaporins. Cell Mol Life Sci 2012; 69:1931-46. [PMID: 22189994 PMCID: PMC11114724 DOI: 10.1007/s00018-011-0903-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 11/07/2011] [Accepted: 11/29/2011] [Indexed: 12/29/2022]
Abstract
Aquaporins (AQPs) are key players regulating urinary-concentrating ability. To date, eight aquaporins have been characterized and localized along the nephron, namely, AQP1 located in the proximal tubule, thin descending limb of Henle, and vasa recta; AQP2, AQP3 and AQP4 in collecting duct principal cells; AQP5 in intercalated cell type B; AQP6 in intercalated cells type A in the papilla; AQP7, AQP8 and AQP11 in the proximal tubule. AQP2, whose expression and cellular distribution is dependent on vasopressin stimulation, is involved in hereditary and acquired diseases affecting urine-concentrating mechanisms. Due to the lack of selective aquaporin inhibitors, the patho-physiological role of renal aquaporins has not yet been completely clarified, and despite extensive studies, several questions remain unanswered. Until the recent and large-scale development of genetic manipulation technology, which has led to the generation of transgenic mice models, our knowledge on renal aquaporin regulation was mainly based on in vitro studies with suitable renal cell models. Transgenic and knockout technology approaches are providing pivotal information on the role of aquaporins in health and disease. The main goal of this review is to update and summarize what we can learn from cell and animal models that will shed more light on our understanding of aquaporin-dependent renal water regulation.
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Affiliation(s)
- G Tamma
- Department of Biosciences, Biotechnologies and Pharmacological Sciences, University of Bari, Italy
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Abstract
The aquaporins are a family of membrane water channels, some of which also transport glycerol. They are involved in a wide range of physiological functions (including water/salt homeostasis, exocrine fluid secretion, and epidermal hydration) and human diseases (including glaucoma, cancer, epilepsy, and obesity). At the cellular level, aquaporin-mediated osmotic water transport across cell plasma membranes facilitates transepithelial fluid transport, cell migration, and neuroexcitation; aquaporin-mediated glycerol transport regulates cell proliferation, adipocyte metabolism, and epidermal water retention. Genetic diseases caused by loss-of-function mutations in aquaporins include nephrogenic diabetes insipidus and congenital cataracts. The neuroinflammatory demyelinating disease neuromyelitis optica is marked by pathogenic autoantibodies against astrocyte water channel aquaporin-4. There remain broad opportunities for the development of aquaporin-based diagnostics and therapeutics. Disease-relevant aquaporin polymorphisms are beginning to be explored. There is great promise in the development of small-molecule aquaporin modulators for therapy of some types of refractory edema, brain swelling, neuroinflammation, glaucoma, epilepsy, cancer, pain, and obesity.
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Affiliation(s)
- A S Verkman
- Department of Medicine, University of California, San Francisco, California 94143-0521, USA.
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Abstract
The central goal of this overview article is to summarize recent findings in renal epithelial transport,focusing chiefly on the connecting tubule (CNT) and the cortical collecting duct (CCD).Mammalian CCD and CNT are involved in fine-tuning of electrolyte and fluid balance through reabsorption and secretion. Specific transporters and channels mediate vectorial movements of water and solutes in these segments. Although only a small percent of the glomerular filtrate reaches the CNT and CCD, these segments are critical for water and electrolyte homeostasis since several hormones, for example, aldosterone and arginine vasopressin, exert their main effects in these nephron sites. Importantly, hormones regulate the function of the entire nephron and kidney by affecting channels and transporters in the CNT and CCD. Knowledge about the physiological and pathophysiological regulation of transport in the CNT and CCD and particular roles of specific channels/transporters has increased tremendously over the last two decades.Recent studies shed new light on several key questions concerning the regulation of renal transport.Precise distribution patterns of transport proteins in the CCD and CNT will be reviewed, and their physiological roles and mechanisms mediating ion transport in these segments will also be covered. Special emphasis will be given to pathophysiological conditions appearing as a result of abnormalities in renal transport in the CNT and CCD.
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Affiliation(s)
- Alexander Staruschenko
- Department of Physiology and Kidney Disease Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
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Merigo F, Mucignat-Caretta C, Cristofoletti M, Zancanaro C. Epithelial membrane transporters expression in the developing to adult mouse vomeronasal organ and olfactory mucosa. Dev Neurobiol 2012; 71:854-69. [PMID: 21721139 DOI: 10.1002/dneu.20944] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
To contribute clarifying mechanisms operating in nose chemosensory epithelia and their developmental patterns, we analyzed the expression of different epithelial membrane transporters as well as the Clara cell secretory protein, CC26 in the olfactory, vomeronasal organ (VNO), and respiratory epithelia of embryonic (E13-E19) and postnatal (P1-P60) mice by means of immunohistochemistry and reverse transcriptase-polymerase chain reaction. Results showed that CC26, cAMP-activated chloride channel (CFTR), and the water channel protein aquaporin 2, 3, 4, and 5 (AQP2, AQP3, AQP4, and AQP5) are expressed in developing to adult chemosensory epithelia with differential timing; moreover, their pattern of expression is not identical in VNO and olfactory epithelia as well as the corresponding associated glands; co-localization experiments using olfactory marker protein showed that CFTR, CC26, and AQP4 are not expressed in olfactory neurones. CFTR is expressed in sustentacular cells of the VNO and olfactory epithelium as well as blood vessels of the underlying mucosa, and VNO (but not Bowman's) glands; a similar pattern (excluding blood vessels) is present for AQP2; AQP4 is found in the two chemosensory epithelia and in Bowman's glands. AQP3 is expressed in the olfactory epithelium and the associated Bowman's glands, but not in the VNO chemosensory epithelium and glands. AQP5 is expressed in the olfactory epithelium and both Bowman's and VNO glands. These results indicate that water/ions handling as well as antioxidant mechanisms operating at the surface and/or inside the nose chemosensory epithelia start developing in utero and are maintained up to sexual maturity.
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Affiliation(s)
- Flavia Merigo
- Department of Neurological, Neuropsychological, Morphological and Movement Sciences, University of Verona, Strada Le Grazie 8, Verona I-37134, Italy
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Abstract
MicroRNAs (miRNAs) are endogenous short (20-22 nucleotides) non-coding RNA molecules that mediate gene expression. This is an important regulatory mechanism to modulate fundamental cellular processes such as differentiation, proliferation, death, metabolism, and pathophysiology of many diseases. The miRNA expression profile of the kidney differs greatly from that of other organs, as well as between the different regions in the kidney. In kidneys, miRNAs are indispensable for development and homeostasis. In this review, we explore the involvement of miRNAs in the regulation of blood pressure, hormone, water, and ion balance pertaining to kidney homeostasis. We also highlight their importance in renal pathophysiology, such as in polycystic disease, diabetic nephropathy, nephrogenic diabetes insipidus, hypertension, renal cancer, and kidney fibrosis (epithelial-mesenchymal transition). In addition, we highlight the need for further investigations on miRNA-based studies in the development of diagnostic, prognostic, and therapeutic tools for renal diseases.
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Abstract
The AQPs (aquaporins) are a family of homologous water transporting proteins expressed in many mammalian epithelial, endothelial and other cell types. Phenotype analysis of mice lacking individual AQPs has been informative in elucidating their role in mammalian physiology. For example, phenotype analysis has indicated an important role of AQPs in the renal urinary concentrating mechanism (AQP1-AQP4), brain water balance and neural signal transduction (AQP4), exocrine gland secretion (AQP5) and ocular fluid balance (AQP1, AQP5). In skin, the aquaglyceroporin AQP3 is expressed in the basal layer of epidermal keratinocytes. Mice deficient in AQP3 have dry skin with reduced SC (stratum corneum) hydration, decreased elasticity and impaired biosynthesis. Mechanistic analysis of the altered skin phenotype in AQP3 deficiency suggested that the glycerol rather than the water transporting function of AQP3 is important in skin physiology. The glycerol content of SC and epidermis of AQP3 deficient mice is reduced, whereas that of dermis and serum is normal. The dry, relatively inelastic skin in AQP3 null mice is probably related to the humectant properties of glycerol, and the impaired SC repair to impaired epidermal biosynthetic function. The key role of AQP3 in epidermal physiology might be exploited in the development of improved cosmetics and new therapies for skin diseases associated with altered skin water content.
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Affiliation(s)
- Mariko Hara-Chikuma
- Departments of Medicine and Physiology, Cardiovascular Research Institute, University of California, San Francisco, CA 94143-0521, USA
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Fenton RA, Praetorius J. Molecular Physiology of the Medullary Collecting Duct. Compr Physiol 2011; 1:1031-56. [DOI: 10.1002/cphy.c100064] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Chen B, Zang CS, Zhang JZ, Wang WG, Wang JG, Zhou HL, Fu YW. The changes of aquaporin 2 in the graft of acute rejection rat renal transplantation model. Transplant Proc 2010; 42:1884-7. [PMID: 20620543 DOI: 10.1016/j.transproceed.2010.02.070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Revised: 01/03/2010] [Accepted: 02/02/2010] [Indexed: 10/19/2022]
Abstract
AIM To investigate the significance and changes of Aquaporin 2 (AQP2) in the rat renal graft of acute rejection (AR). METHODS Wistar recipients of Spraque-Dawley or Wistar renal grafts were treated with cyclosporine (CsA). Renal grafts were harvested at various times after transplantation for analysis of the levels of AQP2 mRNA and protein of by RT-PCR and immunohistochemistry. RESULTS The expression of AQP2 mRNA and protein in the acutely rejecting were grafts significantly decreased (P < 0.05) compared with the control group. But the expression of AQP2 mRNA and protein in the syngeneic grafts (sTX) versus the immunosuppression group (aTX+CsA) showed no difference compared with a control group (P > 0.05). Furthermore, at day 5 and day 7 after transplantation the expressions of AQP2 expression in the allogeneic group (aTX) were decreased significantly compared with day 3 after transplantation (P < 0.05). In addition, there was no remarkable difference at day 5 or 7 after transplantation. CONCLUSION AQP2 mRNA and protein expressions were down-regulated during renal transplant acute rejection, which had no relationship to the ischemia reperfusion injury and denervation damage. Furthermore, CsA administration after kidney transplantation blunted this down-regulation (P > 0.05).
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Affiliation(s)
- B Chen
- First Hospital of The Jinlin University, Changchun, China
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Li JH, Chou CL, Li B, Gavrilova O, Eisner C, Schnermann J, Anderson SA, Deng CX, Knepper MA, Wess J. A selective EP4 PGE2 receptor agonist alleviates disease in a new mouse model of X-linked nephrogenic diabetes insipidus. J Clin Invest 2010; 119:3115-26. [PMID: 19729836 DOI: 10.1172/jci39680] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Accepted: 07/01/2009] [Indexed: 11/17/2022] Open
Abstract
X-linked nephrogenic diabetes insipidus (XNDI) is a severe kidney disease caused by inactivating mutations in the V2 vasopressin receptor (V2R) gene that result in the loss of renal urine-concentrating ability. At present,no specific pharmacological therapy has been developed for XNDI, primarily due to the lack of suitable animal models. To develop what we believe to be the first viable animal model of XNDI, we generated mice in which the V2R gene could be conditionally deleted during adulthood by administration of 4-OH-tamoxifen.Radioligand-binding studies confirmed the lack of V2R-binding sites in kidneys following 4-OH-tamoxifen treatment, and further analysis indicated that upon V2R deletion, adult mice displayed all characteristic symptoms of XNDI, including polyuria, polydipsia, and resistance to the antidiuretic actions of vasopressin. Gene expression analysis suggested that activation of renal EP4 PGE2 receptors might compensate for the lack of renal V2R activity in XNDI mice. Strikingly, both acute and chronic treatment of the mutant mice with a selective EP4 receptor agonist greatly reduced all major manifestations of XNDI, including changes in renal morphology.These physiological improvements were most likely due to a direct action on EP4 receptors expressed on collecting duct cells. These findings illustrate the usefulness of the newly generated V2R mutant mice for elucidating and testing new strategies for the potential treatment of humans with XNDI.
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Affiliation(s)
- Jian Hua Li
- Molecular Signaling Section, National Institute of Diabetes and Digestive and Kidney Diseases,NIH, Bethesda, Maryland, USA
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Shen L, Zhu Z, Huang Y, Shu Y, Sun M, Xu H, Zhang G, Guo R, Wei W, Wu W. Expression profile of multiple aquaporins in human gastric carcinoma and its clinical significance. Biomed Pharmacother 2010; 64:313-8. [PMID: 20106632 DOI: 10.1016/j.biopha.2009.12.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Accepted: 12/01/2009] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND New evidence for involvement of aquaporins (AQPs) in cell migration and proliferation adds AQPs to an expanding list of effectors in tumor biology. But there is few report concerning the expression and role of AQPs in human gastric carcinogenesis so far. The aim of this current study was to investigate the expression profile of AQPs in human gastric carcinoma and its significance. METHODS We screened the expression profile of AQP0 approximately AQP12 in gastric adenocarcinoma tissues and corresponding normal mucosa from 89 patients with gastric cancer by reverse transcriptase polymerase chain reaction (RT-PCR), Western blot analysis and immunochemical assay. The relationship between AQPs expression and clinicopathologic characteristics of patients was evaluated. RESULTS Based on RT-PCR of 13 AQPs examined, AQP1, 3, 4, 5 and 11 were expressed in human gastric cancers or normal gastric tissues, and AQP3, 4 and 5 exhibited differential expression between human gastric carcinomas and corresponding normal tissues, which was confirmed by Western blot analyses. Immunohistochemical assay showed that AQP4 protein was expressed mainly in the membrane of parietal cell and chief cell in the normal gastric mucosa, and absent in carcinoma tissues. AQP3 and AQP5 were detected remarkably stronger in the carcinoma tissues than that in normal mucosa by immunofluorescence. AQP3 expression in cases with undifferentiated tumor was more than that in cases with well-differentiated tumor. Both AQP3 and AQP5 expression were associated with lymph node metastasis and lymphovascular invasion in patients. CONCLUSIONS These findings of differential expressions of AQPs and their correlation with clinicopathologic characteristics implicated AQPs might play a role in human gastric carcinogenesis.
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Affiliation(s)
- Lizong Shen
- Department of General Surgery, First Affiliated Hospital, Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu 210029, PR China.
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Verkman AS. Aquaporins: translating bench research to human disease. ACTA ACUST UNITED AC 2009; 212:1707-15. [PMID: 19448080 DOI: 10.1242/jeb.024125] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
There is considerable potential for translating knowledge of aquaporin structure, function and physiology to the clinic. One area is in aquaporin-based diagnostics. The discovery of AQP4 autoantibodies as a marker of the neuromyelitis optica form of multiple sclerosis has allowed precise diagnosis of this disease. Other aquaporin-based diagnostics are possible. Another area is in aquaporin-based genetics. Genetic diseases caused by loss-of-function mutations in aquaporins include nephrogenic diabetes insipidus and cataracts, and functionally significant aquaporin polymorphisms are beginning to be explored. Perhaps of greatest translational potential is aquaporin-based therapeutics. Information largely from aquaporin knockout mice has implicated key roles of aquaporin-facilitated water transport in transepithelial fluid transport (urinary concentrating, gland fluid secretion), water movement into and out of the brain, cell migration (angiogenesis, tumor metastasis, wound healing) and neural function (sensory signaling, seizures). A subset of aquaporins that transport both water and glycerol, the 'aquaglyceroporins', regulate glycerol content in epidermal, fat and other tissues, and are involved in skin hydration, cell proliferation, carcinogenesis and fat metabolism. Aquaporin-based modulator drugs are predicted to be of broad potential utility in the treatment of edematous states, cancer, obesity, wound healing, epilepsy and glaucoma. These exciting possibilities and their associated challenges are reviewed.
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Affiliation(s)
- A S Verkman
- Department of Medicine, Cardiovascular Research Institute, University of California, San Francisco, CA 94143, USA.
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Chen F. Genetic and developmental basis for urinary tract obstruction. Pediatr Nephrol 2009; 24:1621-32. [PMID: 19085015 PMCID: PMC2844875 DOI: 10.1007/s00467-008-1072-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Revised: 11/15/2008] [Accepted: 11/18/2008] [Indexed: 12/31/2022]
Abstract
Urinary tract obstruction results in obstructive nephropathy and uropathy. It is the most frequent cause of renal failure in infants and children. In the past two decades studies of transgenic models and humans have greatly enhanced our understanding of the genetic factors and developmental processes important in urinary tract obstruction. The emerging picture is that development of the urinary tract requires precise integration of a variety of progenitor cell populations of different embryonic origins. Such integration is controlled by an intricate signaling network that undergoes dynamic changes as the embryo develops. Most congenital forms of urinary tract obstruction result from the disruption of diverse factors and genetic pathways involved in these processes, especially in the morphogenesis of the urinary conduit or the functional aspects of the pyeloureteral peristaltic machinery.
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Affiliation(s)
- Feng Chen
- Renal Division, Department of Internal Medicine, Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Bugaj V, Pochynyuk O, Stockand JD. Activation of the epithelial Na+ channel in the collecting duct by vasopressin contributes to water reabsorption. Am J Physiol Renal Physiol 2009; 297:F1411-8. [PMID: 19692483 DOI: 10.1152/ajprenal.00371.2009] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We used patch-clamp electrophysiology on isolated, split-open murine collecting ducts (CD) to test the hypothesis that regulation of epithelial sodium channel (ENaC) activity is a physiologically important effect of vasopressin. Surprisingly, this has not been tested directly before. We ask whether vasopressin affects ENaC activity distinguishing between acute and chronic effects, as well as, parsing the cellular signaling pathway and molecular mechanism of regulation. In addition, we quantified possible synergistic regulation of ENaC by vasopressin and aldosterone associating this with a requirement for distal nephron Na+ reabsorption during water conservation vs. maintenance of Na+ balance. We find that vasopressin significantly increases ENaC activity within 2-3 min by increasing open probability (P(o)). This activation was dependent on adenylyl cyclase (AC) and PKA. Water restriction (18-24 h) and pretreatment of isolated CD with vasopressin (approximately 30 min) resulted in a similar increase in P(o). In addition, this also increased the number (N) of active ENaC in the apical membrane. Similar to P(o), increases in N were sensitive to inhibitors of AC. Stressing animals with water and salt restriction separately and jointly revealed an important effect of vasopressin: conservation of water and Na+ each independently increased ENaC activity and jointly had a synergistic effect on channel activity. These results demonstrate a quantitatively important action of vasopressin on ENaC suggesting that distal nephron Na+ reabsorption mediated by this channel contributes to maintenance of water reabsorption. In addition, our results support that the combined actions of vasopressin and aldosterone are required to achieve maximally activated ENaC.
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Affiliation(s)
- Vladislav Bugaj
- Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78229-3900, USA
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Bugaj V, Pochynyuk O, Stockand JD. Activation of the epithelial Na+ channel in the collecting duct by vasopressin contributes to water reabsorption. Am J Physiol Renal Physiol 2009. [PMID: 19692483 DOI: 10.1152/ajprenal.00371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We used patch-clamp electrophysiology on isolated, split-open murine collecting ducts (CD) to test the hypothesis that regulation of epithelial sodium channel (ENaC) activity is a physiologically important effect of vasopressin. Surprisingly, this has not been tested directly before. We ask whether vasopressin affects ENaC activity distinguishing between acute and chronic effects, as well as, parsing the cellular signaling pathway and molecular mechanism of regulation. In addition, we quantified possible synergistic regulation of ENaC by vasopressin and aldosterone associating this with a requirement for distal nephron Na+ reabsorption during water conservation vs. maintenance of Na+ balance. We find that vasopressin significantly increases ENaC activity within 2-3 min by increasing open probability (P(o)). This activation was dependent on adenylyl cyclase (AC) and PKA. Water restriction (18-24 h) and pretreatment of isolated CD with vasopressin (approximately 30 min) resulted in a similar increase in P(o). In addition, this also increased the number (N) of active ENaC in the apical membrane. Similar to P(o), increases in N were sensitive to inhibitors of AC. Stressing animals with water and salt restriction separately and jointly revealed an important effect of vasopressin: conservation of water and Na+ each independently increased ENaC activity and jointly had a synergistic effect on channel activity. These results demonstrate a quantitatively important action of vasopressin on ENaC suggesting that distal nephron Na+ reabsorption mediated by this channel contributes to maintenance of water reabsorption. In addition, our results support that the combined actions of vasopressin and aldosterone are required to achieve maximally activated ENaC.
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Affiliation(s)
- Vladislav Bugaj
- Department of Physiology, University of Texas Health Science Center, San Antonio, Texas 78229-3900, USA
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Wu W, Kitamura S, Truong DM, Rieg T, Vallon V, Sakurai H, Bush KT, Vera DR, Ross RS, Nigam SK. Beta1-integrin is required for kidney collecting duct morphogenesis and maintenance of renal function. Am J Physiol Renal Physiol 2009; 297:F210-7. [PMID: 19439520 DOI: 10.1152/ajprenal.90260.2008] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Deletion of integrin-beta1 (Itgb1) in the kidney collecting system led to progressive renal dysfunction and polyuria. The defect in the concentrating ability of the kidney was concomitant with decreased medullary collecting duct expression of aquaporin-2 and arginine vasopressin receptor 2, while histological examination revealed hypoplastic renal medullary collecting ducts characterized by increased apoptosis, ectasia and cyst formation. In addition, a range of defects from small kidneys with cysts and dilated tubules to bilateral renal agenesis was observed. This was likely due to altered growth and branching morphogenesis of the ureteric bud (the progenitor tissue of the renal collecting system), despite the apparent ability of the ureteric bud-derived cells to induce differentiation of the metanephric mesenchyme. These data not only support a role for Itgb1 in the development of the renal collecting system but also raise the possibility that Itgb1 links morphogenesis to terminal differentiation and ultimately collecting duct function and/or maintenance.
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Affiliation(s)
- Wei Wu
- Department of Pediatrics, University of California, La Jolla, California 92093-0693, USA
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Sparrow DB, Boyle SC, Sams RS, Mazuruk B, Zhang L, Moeckel GW, Dunwoodie SL, de Caestecker MP. Placental insufficiency associated with loss of Cited1 causes renal medullary dysplasia. J Am Soc Nephrol 2009; 20:777-86. [PMID: 19297558 DOI: 10.1681/asn.2008050547] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
A number of studies have shown that placental insufficiency affects embryonic patterning of the kidney and leads to a decreased number of functioning nephrons in adulthood; however, there is circumstantial evidence that placental insufficiency may also affect renal medullary growth, which could account for cases of unexplained renal medullary dysplasia and for abnormalities in renal function among infants who had experienced intrauterine growth retardation. We observed that mice with late gestational placental insufficiency associated with genetic loss of Cited1 expression in the placenta had renal medullary dysplasia. This was not caused by lower urinary tract obstruction or by defects in branching of the ureteric bud during early nephrogenesis but was associated with decreased tissue oxygenation and increased apoptosis in the expanding renal medulla. Loss of placental Cited1 was required for Cited1 mutants to develop renal dysplasia, and this was not dependent on alterations in embryonic Cited1 expression. Taken together, these findings suggest that renal medullary dysplasia in Cited1 mutant mice is a direct consequence of decreased tissue oxygenation resulting from placental insufficiency.
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Affiliation(s)
- Duncan B Sparrow
- Developmental Biology Division, Victor Chang Cardiac Research Institute, University of New South Wales, Sydney, Australia
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Abstract
The study of water transport began long before the molecular identification of water channels with studies of water-permeable tissues. The discovery of the first aquaporin, AQP1, occurred during experiments focused on the identity of the Rh blood group antigens. Since then the field has expanded dramatically to study aquaporins in all types of organisms. In mammals, some of the aquaporins transport only water. However, there are some family members that collectively transport a diverse set of solutes. The aquaporins can be regulated by factors that affect channel permeability or subcellular localization. An extensive set of studies examines the physiological role of many of the mammalian aquaporins. However, much is still to be discovered about the physiological role of this membrane protein family.
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Sohara E, Uchida S, Sasaki S. Function of aquaporin-7 in the kidney and the male reproductive system. Handb Exp Pharmacol 2008:219-31. [PMID: 19096780 DOI: 10.1007/978-3-540-79885-9_11] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
The aquaporin-7 (AQP7) water channel is known to be a member of the aquaglyceroporins, which allow the rapid transport of glycerol and water. In this chapter, we review the physiological functions of AQP7 in the kidney and the male reproductive system.In the kidney, AQP7 is abundantly present at the apical membrane of the proximal straight tubules. Although the contribution of AQP7 to the water permeability of proximal straight tubules was found to be minimal compared with that of AQP1, we identified a novel glycerol reabsorption pathway that may be important for preventing glycerol from being excreted into urine.In the male reproductive system, AQP7 is present particularly in the spermatids, as well as in the testicular and epididymal spermatozoa, suggesting that AQP7 has some role in late spermatogenesis. However, male AQP7 knockout mice were not sterile, and their sperm did not show any morphological or functional abnormalities.
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Affiliation(s)
- Eisei Sohara
- Department of Nephrology, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan
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