1
|
Liang Y, Chen P, Wang S, Cai L, Zhu F, Jiang Y, Li L, Zhu L, Heng Y, Zhang W, Pan Y, Wei W, Jia L. SCF FBXW5-mediated degradation of AQP3 suppresses autophagic cell death through the PDPK1-AKT-MTOR axis in hepatocellular carcinoma cells. Autophagy 2024:1-16. [PMID: 38726865 DOI: 10.1080/15548627.2024.2353497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 05/05/2024] [Indexed: 05/20/2024] Open
Abstract
AQP3 (aquaporin 3 (Gill blood group)), a member of the AQP family, is an aquaglyceroporin which transports water, glycerol and small solutes across the plasma membrane. Beyond its role in fluid transport, AQP3 plays a significant role in regulating various aspects of tumor cell behavior, including cell proliferation, migration, and invasion. Nevertheless, the underlying regulatory mechanism of AQP3 in tumors remains unclear. Here, for the first time, we report that AQP3 is a direct target for ubiquitination by the SCFFBXW5 complex. In addition, we revealed that downregulation of FBXW5 significantly induced AQP3 expression to prompt macroautophagic/autophagic cell death in hepatocellular carcinoma (HCC) cells. Mechanistically, AQP3 accumulation induced by FBXW5 knockdown led to the degradation of PDPK1/PDK1 in a lysosomal-dependent manner, thus inactivating the AKT-MTOR pathway and inducing autophagic death in HCC. Taken together, our findings revealed a previously undiscovered regulatory mechanism through which FBXW5 degraded AQP3 to suppress autophagic cell death via the PDPK1-AKT-MTOR axis in HCC cells.Abbreviation: BafA1: bafilomycin A1; CQ: chloroquine; CRL: CUL-Ring E3 ubiquitin ligases; FBXW5: F-box and WD repeat domain containing 5; HCC: hepatocellular carcinoma; HSPA8/HSC70: heat shock protein family A (Hsp70) member 8; 3-MA: 3-methyladenine; PDPK1/PDK1: 3-phosphoinositide dependent protein kinase 1; RBX1/ROC1: ring-box 1; SKP1: S-phase kinase associated protein 1; SCF: SKP1-CUL1-F-box protein.
Collapse
Affiliation(s)
- Yupei Liang
- Cancer Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ping Chen
- School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Shiwen Wang
- Department of Laboratory Medicine, Huadong Hospital Affiliated to Fudan University, Shanghai, China
| | - Lili Cai
- Cancer Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Feng Zhu
- Department of Laboratory Medicine, Huadong Hospital Affiliated to Fudan University, Shanghai, China
| | - Yanyu Jiang
- Cancer Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Lihui Li
- Cancer Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Lihua Zhu
- Cancer Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yongqing Heng
- Department of Integrative Medicine, Shanghai Pulmonary Hospital, Tongji University, Shanghai, China
| | - Wenjuan Zhang
- Department of Breast Surgery, Key Laboratory of Breast Cancer in Shanghai, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Yongfu Pan
- Cancer Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Lijun Jia
- Cancer Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| |
Collapse
|
2
|
Ernstsen CV, Ranieri M, Login FH, Mahmoud IK, Therkildsen JR, Valenti G, Praetorius H, Nørregaard R, Nejsum LN. Regulation of renal aquaporin water channels in acute pyelonephritis. Am J Physiol Cell Physiol 2024; 326:C1451-C1461. [PMID: 38525539 DOI: 10.1152/ajpcell.00308.2023] [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: 07/10/2023] [Revised: 02/28/2024] [Accepted: 03/11/2024] [Indexed: 03/26/2024]
Abstract
Acute pyelonephritis (APN) is most frequently caused by uropathogenic Escherichia coli (UPEC), which ascends from the bladder to the kidneys during a urinary tract infection. Patients with APN have been reported to have reduced renal concentration capacity under challenged conditions, polyuria, and increased aquaporin-2 (AQP2) excretion in the urine. We have recently shown increased AQP2 accumulation in the plasma membrane in cell cultures exposed to E. coli lysates and in the apical plasma membrane of inner medullary collecting ducts in a 5-day APN mouse model. This study aimed to investigate if AQP2 expression in host cells increases UPEC infection efficiency and to identify specific bacterial components that mediate AQP2 plasma membrane insertion. As the transepithelial water permeability in the collecting duct is codetermined by AQP3 and AQP4, we also investigated whether AQP3 and AQP4 localization is altered in the APN mouse model. We show that AQP2 expression does not increase UPEC infection efficiency and that AQP2 was targeted to the plasma membrane in AQP2-expressing cells in response to the two pathogen-associated molecular patterns (PAMPs), lipopolysaccharide and peptidoglycan. In contrast to AQP2, the subcellular localizations of AQP1, AQP3, and AQP4 were unaffected both in lysate-incubated cell cultures and in the APN mouse model. Our finding demonstrated that cellular exposure to lipopolysaccharide and peptidoglycan can trigger the insertion of AQP2 in the plasma membrane revealing a new regulatory pathway for AQP2 plasma membrane translocation, which may potentially be exploited in intervention strategies.NEW & NOTEWORTHY Acute pyelonephritis (APN) is associated with reduced renal concentration capacity and increased aquaporin-2 (AQP2) excretion. Uropathogenic Escherichia coli (UPEC) mediates changes in the subcellular localization of AQP2 and we show that in vitro, these changes could be elicited by two pathogen-associated molecular patterns (PAMPs), namely, lipopolysaccharide and peptidoglycan. UPEC infection was unaltered by AQP2 expression and the other renal AQPs (AQP1, AQP3, and AQP4) were unaltered in APN.
Collapse
Affiliation(s)
| | - Marianna Ranieri
- Department of Biosciences, Biotechnology and Environment, University of Bari, Bari, Italy
| | - Frédéric H Login
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Isra K Mahmoud
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | | | - Giovanna Valenti
- Department of Biosciences, Biotechnology and Environment, University of Bari, Bari, Italy
| | | | - Rikke Nørregaard
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Lene N Nejsum
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| |
Collapse
|
3
|
Cutler CP, Canicatti ME, Omoregie E. Evidence That Aquaporin 11 (AQP11) in the Spiny Dogfish ( Squalus acanthias) May Represent a Pseudogene. Int J Mol Sci 2024; 25:2028. [PMID: 38396705 PMCID: PMC10889150 DOI: 10.3390/ijms25042028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 01/15/2024] [Accepted: 01/20/2024] [Indexed: 02/25/2024] Open
Abstract
Various attempts to amplify an AQP11 cDNA from tissues of the spiny dogfish (Squalus acanthias) were made. Two pairs of deoxy-inosine-containing degenerate primers were designed based on conserved amino acid sequences from an AQP11 alignment. These primers yielded some faint bands from gill cDNA that were sequenced. Blast searches with the sequences showed they were not AQP11. An elasmobranch AQP11 nucleotide sequence alignment was produced to identify conserved regions to make further degenerate primers. One primer pair produced a short 148 bp fragment showing particularly strong amplification in gill and intestine. It was sequenced and represented a piece of the AQP11 gene. However, as the fragment may have resulted from contaminating genomic DNA (in total RNA used to make cDNA), 5' and 3' RACE were performed to amplify the two ends of the putative cDNA. Furthermore, 5' and 3' RACE amplifications depend on the presence of a 5' cap nucleotide and a poly A tail, respectively on the putative AQP11 mRNA. Hence, successful amplification was only possible from cDNA and not genomic DNA. Nested RACE amplifications were performed using gill and intestinal RACE cDNA, but none of the DNA fragments sequenced were AQP11. Consequently, the spiny dogfish AQP11 gene may represent a pseudogene.
Collapse
Affiliation(s)
- Christopher P. Cutler
- Biology Department, Georgia Southern University, P.O. Box 8042, Statesboro, GA 30460, USA
| | | | | |
Collapse
|
4
|
Login FH, Dam VS, Nejsum LN. Following the cellular itinerary of renal aquaporin-2 shuttling with 4.5x expansion microscopy. Am J Physiol Cell Physiol 2024; 326:C194-C205. [PMID: 38047301 DOI: 10.1152/ajpcell.00397.2023] [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: 08/21/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 12/05/2023]
Abstract
The shuttling of renal collecting duct aquaporin-2 (AQP2) between intracellular vesicles and the apical plasma membrane is paramount for regulation of renal water reabsorption. The binding of the circulating antidiuretic hormone arginine vasopressin (AVP) to the basolateral AVP receptor increases intracellular cAMP, which ultimately leads to AQP2 plasma membrane accumulation via a dual effect on AQP2 vesicle fusion with the apical plasma membrane and reduced AQP2 endocytosis. This AQP2 plasma membrane accumulation increases water reabsorption and consequently urine concentration. Conventional fluorescent microscopy provides a lateral resolution of ∼250 nm, which is insufficient to resolve the AQP2-containing endosomes/vesicles. Therefore, detailed information regarding the AQP2 vesicular population is still lacking. Newly established 4.5x Expansion Microscopy (ExM) can increase resolution to 60-70 nm. Using 4.5x ExM, we detected AQP2 vesicles/endosomes as small as 79 nm considering an average expansion factor of 4.3 for endosomes. Using different markers of the endosomal system provided detailed information of the cellular AQP2 itinerary upon changes in endogenous cAMP levels. Before cAMP elevation, AQP2 colocalized with early and recycling, but not late endosomes. Forskolin-induced cAMP increase was characterized by AQP2 insertion into the plasma membrane and AQP2 withdrawal from large perinuclear endosomes as well as some localization to lysosomal compartments. Forskolin washout promoted AQP2 endocytosis where AQP2 localized to not only early and recycling endosomes but also late endosomes and lysosomes indicating increased AQP2 degradation. Thus, our results show that 4.5 ExM is an attractive approach to obtain detailed information regarding AQP2 shuttling.NEW & NOTEWORTHY Renal aquaporin-2 (AQP2) imaged by expansion microscopy provides unprecedented 3-D information regarding the AQP2 itinerary in response to changes in cellular cAMP.
Collapse
Affiliation(s)
- Frédéric H Login
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Vibeke S Dam
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Lene N Nejsum
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| |
Collapse
|
5
|
Lin YT, Wu SY, Lee TH. Salinity effects on expression and localization of aquaporin 3 in gills of the euryhaline milkfish (Chanos chanos). JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2023; 339:951-960. [PMID: 37574887 DOI: 10.1002/jez.2744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 06/28/2023] [Accepted: 07/27/2023] [Indexed: 08/15/2023]
Abstract
Milkfish (Chanos chanos) are important euryhaline fish in Southeast Asian countries that can tolerate a wide range of salinity changes. Previous studies have revealed that milkfish have strong ion regulation and survival abilities under osmotic stress. In addition to ion regulation, water homeostasis in euryhaline teleosts is important during environmental salinity shifts. Aquaporins (AQP) are vital water channels in fish, and different AQPs can transport water influx or outflux from the body. AQP3 is one of the AQP channels, and the function of AQP3 in the gills of euryhaline milkfish is still unknown. The aim of this study was to investigate the expression and localization of AQP3 in the gills of euryhaline milkfish to contribute to our understanding of the physiological role and localization of AQP3 in fish. The AQP3 sequence was found in the milkfish next-generation sequencing (NGS) database and is mainly distributed in the gills of freshwater (FW)-acclimated milkfish. Under hypoosmotic and hyperosmotic stress, the osmolality of milkfish immediately shifted, similar to the aqp3 gene expression. Moreover, the abundance of AQP3 protein significantly decreased 3 h after transferring milkfish from FW to seawater (SW). However, there was no change within 7 days when the milkfish experienced hypoosmotic stress. Moreover, double immunofluorescence staining of milkfish gills showed that AQP3 colocalized with Na+ /K+ ATPase at the basolateral membrane of ionocytes. These results combined indicate that milkfish have a strong osmoregulation ability under acute osmotic stress because of the quick shift in the gene and protein expression of AQP3 in their gills.
Collapse
Affiliation(s)
- Yu-Ting Lin
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
- The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
| | - Shao-Ying Wu
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Tsung-Han Lee
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
- The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
| |
Collapse
|
6
|
Zulueta Díaz YDLM, Kure JL, Grosso RA, Andersen C, Pandzic E, Sengupta P, Wiseman PW, Arnspang EC. Quantitative image mean squared displacement (iMSD) analysis of the dynamics of Aquaporin 2 within the membrane of live cells. Biochim Biophys Acta Gen Subj 2023; 1867:130449. [PMID: 37748662 DOI: 10.1016/j.bbagen.2023.130449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 08/22/2023] [Accepted: 08/25/2023] [Indexed: 09/27/2023]
Abstract
Nanodomains are a biological membrane phenomenon which have a large impact on various cellular processes. They are often analysed by looking at the lateral dynamics of membrane lipids or proteins. The localization of the plasma membrane protein aquaporin-2 in nanodomains has so far been unknown. In this study, we use total internal reflection fluorescence microscopy to image Madin-Darby Canine Kidney (MDCK) cells expressing aquaporin-2 tagged with mEos 3.2. Then, image mean squared displacement (iMSD) approach was used to analyse the diffusion of aquaporin-2, revealing that aquaporin-2 is confined within membrane nanodomains. Using iMSD analysis, we found that the addition of the drug forskolin increases the diffusion of aquaporin-2 within the confined domains, which is in line with previous studies. Finally, we observed an increase in the size of the membrane domains and the extent of trapping of aquaporin-2 after stimulation with forskolin.
Collapse
Affiliation(s)
| | - Jakob Lavrsen Kure
- Department of Green Technology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Rubén Adrián Grosso
- Department of Green Technology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Camilla Andersen
- Department of Green Technology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Elvis Pandzic
- Mark Wainwright Analytical Centre, Lowy Cancer Research Centre C25, University of New South Wales, NSW, 2052, Australia
| | - Prabuddha Sengupta
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA; Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Paul W Wiseman
- Department of Chemistry, McGill University, Montreal, Québec, Canada; Department of Physics, McGill University, Montreal, Québec, Canada
| | - Eva C Arnspang
- Department of Green Technology, University of Southern Denmark, 5230 Odense M, Denmark; The Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
| |
Collapse
|
7
|
Login FH, Nejsum LN. Aquaporin water channels: roles beyond renal water handling. Nat Rev Nephrol 2023; 19:604-618. [PMID: 37460759 DOI: 10.1038/s41581-023-00734-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2023] [Indexed: 08/18/2023]
Abstract
Aquaporin (AQP) water channels are pivotal to renal water handling and therefore in the regulation of body water homeostasis. However, beyond the kidney, AQPs facilitate water reabsorption and secretion in other cells and tissues, including sweat and salivary glands and the gastrointestinal tract. A growing body of evidence has also revealed that AQPs not only facilitate the transport of water but also the transport of several small molecules and gases such as glycerol, H2O2, ions and CO2. Moreover, AQPs are increasingly understood to contribute to various cellular processes, including cellular migration, adhesion and polarity, and to act upstream of several intracellular and intercellular signalling pathways to regulate processes such as cell proliferation, apoptosis and cell invasiveness. Of note, several AQPs are highly expressed in multiple cancers, where their expression can correlate with the spread of cancerous cells to lymph nodes and alter the response of cancers to conventional chemotherapeutics. These data suggest that AQPs have diverse roles in various homeostatic and physiological systems and may be exploited for prognostics and therapeutic interventions.
Collapse
Affiliation(s)
- Frédéric H Login
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Lene N Nejsum
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
| |
Collapse
|
8
|
Oernbo EK, Steffensen AB, Razzaghi Khamesi P, Toft-Bertelsen TL, Barbuskaite D, Vilhardt F, Gerkau NJ, Tritsaris K, Simonsen AH, Lolansen SD, Andreassen SN, Hasselbalch SG, Zeuthen T, Rose CR, Kurtcuoglu V, MacAulay N. Membrane transporters control cerebrospinal fluid formation independently of conventional osmosis to modulate intracranial pressure. Fluids Barriers CNS 2022; 19:65. [PMID: 36038945 PMCID: PMC9422132 DOI: 10.1186/s12987-022-00358-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 07/13/2022] [Indexed: 11/23/2022] Open
Abstract
Background Disturbances in the brain fluid balance can lead to life-threatening elevation in the intracranial pressure (ICP), which represents a vast clinical challenge. Nevertheless, the details underlying the molecular mechanisms governing cerebrospinal fluid (CSF) secretion are largely unresolved, thus preventing targeted and efficient pharmaceutical therapy of cerebral pathologies involving elevated ICP. Methods Experimental rats were employed for in vivo determinations of CSF secretion rates, ICP, blood pressure and ex vivo excised choroid plexus for morphological analysis and quantification of expression and activity of various transport proteins. CSF and blood extractions from rats, pigs, and humans were employed for osmolality determinations and a mathematical model employed to determine a contribution from potential local gradients at the surface of choroid plexus. Results We demonstrate that CSF secretion can occur independently of conventional osmosis and that local osmotic gradients do not suffice to support CSF secretion. Instead, the CSF secretion across the luminal membrane of choroid plexus relies approximately equally on the Na+/K+/2Cl− cotransporter NKCC1, the Na+/HCO3− cotransporter NBCe2, and the Na+/K+-ATPase, but not on the Na+/H+ exchanger NHE1. We demonstrate that pharmacological modulation of CSF secretion directly affects the ICP. Conclusions CSF secretion appears to not rely on conventional osmosis, but rather occur by a concerted effort of different choroidal transporters, possibly via a molecular mode of water transport inherent in the proteins themselves. Therapeutic modulation of the rate of CSF secretion may be employed as a strategy to modulate ICP. These insights identify new promising therapeutic targets against brain pathologies associated with elevated ICP. Supplementary Information The online version contains supplementary material available at 10.1186/s12987-022-00358-4.
Collapse
Affiliation(s)
- Eva K Oernbo
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Annette B Steffensen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Pooya Razzaghi Khamesi
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Trine L Toft-Bertelsen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Dagne Barbuskaite
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Frederik Vilhardt
- Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Niklas J Gerkau
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225, Düsseldorf, Germany
| | - Katerina Tritsaris
- Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Anja H Simonsen
- Danish Dementia Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Sara D Lolansen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Søren N Andreassen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Steen G Hasselbalch
- Danish Dementia Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Zeuthen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Christine R Rose
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225, Düsseldorf, Germany
| | - Vartan Kurtcuoglu
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Nanna MacAulay
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark.
| |
Collapse
|
9
|
The aquaporin 8 (AQP8) membrane channel gene is present in the elasmobranch dogfish (Squalus acanthias) genome and is expressed in brain but not in gill, kidney or intestine. Comp Biochem Physiol B Biochem Mol Biol 2022; 260:110730. [PMID: 35248695 DOI: 10.1016/j.cbpb.2022.110730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/27/2022] [Accepted: 03/01/2022] [Indexed: 11/23/2022]
Abstract
The transport mechanisms for water, ammonia and urea in elasmobranch gill, kidney and gastrointestinal tract remain to be fully elucidated. Aquaporin 8 (AQP8) is a known water, ammonia and urea channel that is expressed in the kidney and respiratory and gastrointestinal tracts of mammals and teleost fish. However, at the initiation of this study in late 2019, there was no copy of an elasmobranch aquaporin 8 gene identified in the genebank even for closely related holocephalon species such as elephant fish (Callorhinchus milii) or for the elasmobranch little skate (Leucoraja erinacea). A transcriptomic study in spiny dogfish (Squalus acanthias) also failed to identify a copy. Hence this study has remedied this and identified the AQP8 cDNA sequence using degenerate PCR. Agarose electrophoresis of degenerate PCR reactions from dogfish tissues showed a strong band from brain cDNA and faint bands of a similar size in gill and liver. 5' and 3' RACE was used to complete the AQP8 cDNA sequence. Primers were then designed for further PCR reactions to determine the distribution of AQP8 mRNA expression in dogfish tissues. This showed that AQP8 is only expressed in dogfish brain and AQP8 therefore clearly can play no role in water, ammonia and urea transport in the gill, kidney or gastrointestinal tract. The role of AQP8 in dogfish brain remains to be determined.
Collapse
|
10
|
Aquaporin (AQP) channels in the spiny dogfish, Squalus acanthias II: Localization of AQP3, AQP4 and AQP15 in the kidney. Comp Biochem Physiol B Biochem Mol Biol 2021; 258:110701. [PMID: 34856347 DOI: 10.1016/j.cbpb.2021.110701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 11/19/2021] [Accepted: 11/25/2021] [Indexed: 11/22/2022]
Abstract
Three aquaporin water channel proteins, AQP3, AQP4 and AQP15 were localized to cells within the kidney of the spiny dogfish, Squalus acanthias, using an immunohistochemical approach. Dogfish kidney has two zones, the bundle zone (including five nephron segment bundles) and the sinus zone (with two major loops). In order to discriminate between the two loops, the cilia occurring in the first proximal/intermediate loop were labeled with two antibodies including an anti-acetylated tubulin antibody. The second late distal tubule loop (LDT) was identified, as the nephron in that region has no luminal cilia. Strong staining of the rabbit anti-dogfish AQP3, AQP4 (AQP4/2) or AQP15 polyclonal antibodies localized to LDT tubules. These antibodies were further co-stained with a mouse anti-Na+,K+-ATPase a5 monoclonal antibody, as Na+,K+-ATPase has previously been suggested to localize to the early distal tubule (EDT) and LDT and a mouse anti-NKCC T4 antibody, as NKCC2 was previously suggested to be located in the EDT and the second half of the LDT. In the LDT, strong AQP4/2 and AQP15 antibody staining localized together with the strong Na+,K+-ATPase antibody staining, whereas strong AQP3 antibody staining was largely separate but with an overlapping distribution. Very low levels of AQP4/2 antibody basal membrane staining was also detected in the first proximal /intermediate loop of the sinus zone. There was no mouse anti-NKCC T4 antibody staining apparent in the LDT. In the convoluted part of the bundle zone, the AQP4/2 and Na+,K+-ATPase but not the AQP3 or AQP15 antibodies stained tubule segments, with both AQP4/2 and Na+,K+-ATPase staining the EDT, and with low-level AQP4/2 staining of two other tubules of the bundle, which were most likely to be the proximal 1a (PIa) and intermediate II (IS II) tubules. The AQP4/2 antibody also stained the EDT in the straight bundle zone. The mouse anti-NKCC T4 antibody stained the apical region of EDT tubules in the convoluted bundle zone, suggesting that the antibody was binding to the NKCC2 cotransporter. The AQP15 antibody appeared to bind to the peritubular sheath surrounding bundles in the bundle zone. Due to the AQP4/2 antibody staining in the EDT that immediately proceeds and continues into the LDT, this suggested that the strong AQP4/2, AQP15 and Na+,K+-ATPase antibody staining was located at the beginning of the LDT and therefore the strong AQP3 was located at the end of the LDT. The staining of all three AQP antibodies was blocked by the peptide-antigen used to make each one, suggesting that all the staining is specific to each antibody.
Collapse
|
11
|
Holst MR, Nejsum LN. A versatile aquaporin-2 cell system for quantitative temporal expression and live cell imaging. Am J Physiol Renal Physiol 2019; 317:F124-F132. [PMID: 31091121 DOI: 10.1152/ajprenal.00150.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Aquaporin-2 (AQP2) fine tunes urine concentration in response to the antidiuretic hormone vasopressin. In addition, AQP2 has been suggested to promote cell migration and epithelial morphogenesis. A cell system allowing temporal and quantitative control of expression levels of AQP2 and phospho-mimicking mutants has been missing, as has a system allowing expression of fluorescently tagged AQP2 for time-lapse imaging. In the present study, we generated and validated a Flp-In T-REx Madin-Darby canine kidney cell system for temporal and quantitative control of AQP2 and phospho-mimicking mutants. We verified that expression levels can be temporally and quantitatively controlled and that AQP2 translocated to the plasma membrane in response to elevated cAMP, which also induced S256 phosphorylation. The phospho-mimicking mutants AQP2-S256A and AQP2-S256D localized as previously described, primarily intracellular and to the plasma membrane, respectively. Induction of AQP2 expression in combination with transient, low expression of enhanced green fluorescent protein-tagged AQP2 enabled expression without aggregation and correct translocation in response to elevated cAMP. Interestingly, time-lapse imaging revealed AQP2-containing tubulating endosomes and that tubulation significantly decreased 30 min after cAMP elevation. This was mirrored by the phospho-mimicking mutants AQP2-S256A and AQP2-S256D, where AQP2-S256A-containing endosomes tubulated, whereas AQP2-S256D-containing endosomes did not. Thus, this cell system enables a multitude of cell-based assays warranted to provide deeper insights into the mechanisms of AQP2 regulation and effects on cell migration and epithelial morphogenesis.
Collapse
Affiliation(s)
- Mikkel R Holst
- Department of Clinical Medicine, Aarhus University , Aarhus , Denmark
| | - Lene N Nejsum
- Department of Clinical Medicine, Aarhus University , Aarhus , Denmark
| |
Collapse
|
12
|
Arnspang EC, Sengupta P, Mortensen KI, Jensen HH, Hahn U, Jensen EBV, Lippincott-Schwartz J, Nejsum LN. Regulation of Plasma Membrane Nanodomains of the Water Channel Aquaporin-3 Revealed by Fixed and Live Photoactivated Localization Microscopy. NANO LETTERS 2019; 19:699-707. [PMID: 30584808 DOI: 10.1021/acs.nanolett.8b03721] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Several aquaporin (AQP) water channels are short-term regulated by the messenger cyclic adenosine monophosphate (cAMP), including AQP3. Bulk measurements show that cAMP can change diffusive properties of AQP3; however, it remains unknown how elevated cAMP affects AQP3 organization at the nanoscale. Here we analyzed AQP3 nano-organization following cAMP stimulation using photoactivated localization microscopy (PALM) of fixed cells combined with pair correlation analysis. Moreover, in live cells, we combined PALM acquisitions of single fluorophores with single-particle tracking (spt-PALM). These analyses revealed that AQP3 tends to cluster and that the diffusive mobility is confined to nanodomains with radii of ∼150 nm. This domain size increases by ∼30% upon elevation of cAMP, which, however, is not accompanied by a significant increase in the confined diffusion coefficient. This regulation of AQP3 organization at the nanoscale may be important for understanding the mechanisms of water AQP3-mediated water transport across plasma membranes.
Collapse
Affiliation(s)
- Eva C Arnspang
- Department of Clinical Medicine , Aarhus University Aarhus DK-8000 , Denmark
- Interdisciplinary Nanoscience Center (iNANO) , Aarhus University , Aarhus DK-8000 , Denmark
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development , National Institutes of Health , Bethesda , Maryland 20892 , United States
- Department of Chemical Engineering, Biotechnology and Environmental Technology , University of Southern Denmark , Odense M DK-5230 , Denmark
| | - Prabuddha Sengupta
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development , National Institutes of Health , Bethesda , Maryland 20892 , United States
- Janelia Research Campus , Ashburn , Virginia 20147 , United States
| | - Kim I Mortensen
- Department of Micro- and Nanotechnology , Technical University of Denmark , Kongens Lyngby DK-2800 , Denmark
| | - Helene H Jensen
- Department of Clinical Medicine , Aarhus University Aarhus DK-8000 , Denmark
- Department of Molecular Biology and Genetics , Aarhus University , Aarhus DK-8000 , Denmark
| | - Ute Hahn
- Department of Mathematics , Aarhus University , Aarhus DK-8000 , Denmark
| | - Eva B V Jensen
- Department of Mathematics , Aarhus University , Aarhus DK-8000 , Denmark
| | - Jennifer Lippincott-Schwartz
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development , National Institutes of Health , Bethesda , Maryland 20892 , United States
- Janelia Research Campus , Ashburn , Virginia 20147 , United States
| | - Lene N Nejsum
- Department of Clinical Medicine , Aarhus University Aarhus DK-8000 , Denmark
- Interdisciplinary Nanoscience Center (iNANO) , Aarhus University , Aarhus DK-8000 , Denmark
| |
Collapse
|
13
|
Jensen HH, Holst MR, Login FH, Morgen JJ, Nejsum LN. Ectopic expression of aquaporin-5 in noncancerous epithelial MDCK cells changes cellular morphology and actin fiber formation without inducing epithelial-to-mesenchymal transition. Am J Physiol Cell Physiol 2018; 314:C654-C661. [DOI: 10.1152/ajpcell.00186.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Aquaporin-5 (AQP5) is a plasma membrane water channel mainly expressed in secretory glands. Increased expression of AQP5 is observed in multiple cancers, including breast cancer, where high expression correlates with the degree of metastasis and poor prognosis. Moreover, studies in cancer cells have suggested that AQP5 activates Ras signaling, drives morphological changes, and in particular increased invasiveness. To design intervention strategies, it is of utmost importance to characterize and dissect the cell biological changes induced by altered AQP5 expression. To isolate the effect of AQP5 overexpression from the cancer background, AQP5 was overexpressed in normal epithelial MDCK cells which have no endogenous AQP5 expression. AQP5 overexpression promoted actin stress fiber formation and lamellipodia dynamics. Moreover, AQP5 decreased cell circularity. Phosphorylation of AQP5 on serine 156 in the second intracellular loop has been shown to activate the Ras pathway. When serine 156 was mutated to alanine to mimic the nonphosphorylated state, the decrease in cell circularity was reversed, indicating that the AQP5-Ras axis is involved in the effect on cell shape. Interestingly, the cellular changes mediated by AQP5 were not associated with induction of epithelial-to-mesenchymal transition. Thus, AQP5 may contribute to cancer by altering cellular morphology and actin organization, which increase the metastatic potential.
Collapse
Affiliation(s)
- Helene H. Jensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Mikkel R. Holst
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | - Jeanette J. Morgen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Lene N. Nejsum
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| |
Collapse
|
14
|
Abstract
Increasing evidence suggests that the water/glycerol channel aquaporin-3 (AQP3) plays a pivotal role in cancer metastasis. AQP3 knockout mice were resistant to skin tumor formation and overexpression correlated with metastasis and poor prognosis in patients with breast or gastric cancer. In cultured cancer cells, increased AQP3 expression stimulated several intracellular signaling pathways and resulted in increased cell proliferation, migration, and invasion as well as aggravation of epithelial-to-mesenchymal transition. Besides AQP facilitated water transport at the leading edge of migrating cells, AQP3 signaling mechanisms are beginning to be unraveled. Here, we give a thorough review of current knowledge regarding AQP3 expression in cancer and how AQP3 contributes to cancer progression via signaling that modulates cellular mechanisms. This review article will expand our understanding of the known pathophysiological findings regarding AQP3 in cancer.
Collapse
|
15
|
Jensen HH, Login FH, Park JY, Kwon TH, Nejsum LN. Immunohistochemical evalulation of activated Ras and Rac1 as potential downstream effectors of aquaporin-5 in breast cancer in vivo. Biochem Biophys Res Commun 2017; 493:1210-1216. [PMID: 28958942 DOI: 10.1016/j.bbrc.2017.09.125] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 09/23/2017] [Indexed: 11/29/2022]
Abstract
Aberrant levels of aquaporin-5 (AQP5) expression have been observed in several types of cancer, including breast cancer, where AQP5 overexpression is associated with metastasis and poor prognosis. In cultured cancer cells, AQP5 facilitates cell migration and activates Ras signaling. Both increased cell migration and Ras activation are associated with cancer metastasis, but so far it is unknown if AQP5 also affects these processes in vivo. Therefore, we investigated if high AQP5 expression in breast cancer tissue correlated with increased activation of Ras and of Rac1, which is a GTPase also involved in cell migration. This was accomplished by immunohistochemical analysis of invasive ductal carcinoma of breast tissue sections from human patients, followed by qualitative and quantitative correlation analysis between AQP5 and activated Ras and Rac1. Immunohistochemistry revealed that activation of Ras and Rac1 was positively correlated. There was, however, no correlation between high AQP5 expression and activation of Ras, whereas a nonsignificant, but positive, tendency between the levels of AQP5 and activated Rac1 levels was observed. In summary, this is the first report that correlates AQP5 expression levels to downstream signaling partners in breast cancer tissue sections. The results suggest Rac1 as a potential downstream signaling partner of AQP5 in vivo.
Collapse
Affiliation(s)
- Helene H Jensen
- Department of Clinical Medicine, Aarhus University, DK-8000, Aarhus, Denmark; Department of Molecular Biology and Genetics, Aarhus University, DK-8000, Aarhus, Denmark
| | - Frédéric H Login
- Department of Clinical Medicine, Aarhus University, DK-8000, Aarhus, Denmark
| | - Ji-Young Park
- Department of Pathology, School of Medicine, Kyungpook National University, Taegu, 41944, South Korea
| | - Tae-Hwan Kwon
- Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Taegu, 41944, South Korea.
| | - Lene N Nejsum
- Department of Clinical Medicine, Aarhus University, DK-8000, Aarhus, Denmark.
| |
Collapse
|
16
|
Arnspang EC, Login FH, Koffman JS, Sengupta P, Nejsum LN. AQP2 Plasma Membrane Diffusion Is Altered by the Degree of AQP2-S256 Phosphorylation. Int J Mol Sci 2016; 17:ijms17111804. [PMID: 27801846 PMCID: PMC5133805 DOI: 10.3390/ijms17111804] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 09/15/2016] [Accepted: 09/22/2016] [Indexed: 01/21/2023] Open
Abstract
Fine tuning of urine concentration occurs in the renal collecting duct in response to circulating levels of arginine vasopressin (AVP). AVP stimulates intracellular cAMP production, which mediates exocytosis of sub-apical vesicles containing the water channel aquaporin-2 (AQP2). Protein Kinase A (PKA) phosphorylates AQP2 on serine-256 (S256), which triggers plasma membrane accumulation of AQP2. This mediates insertion of AQP2 into the apical plasma membrane, increasing water permeability of the collecting duct. AQP2 is a homo-tetramer. When S256 on all four monomers is changed to the phosphomimic aspartic acid (S256D), AQP2-S256D localizes to the plasma membrane and internalization is decreased. In contrast, when S256 is mutated to alanine (S256A) to mimic non-phosphorylated AQP2, AQP2-S256A localizes to intracellular vesicles as well as the plasma membrane, with increased internalization from the plasma membrane. S256 phosphorylation is not necessary for exocytosis and dephosphorylation is not necessary for endocytosis, however, the degree of S256 phosphorylation is hypothesized to regulate the kinetics of AQP2 endocytosis and thus, retention time in the plasma membrane. Using k-space Image Correlation Spectroscopy (kICS), we determined how the number of phosphorylated to non-phosphorylated S256 monomers in the AQP2 tetramer affects diffusion speed of AQP2 in the plasma membrane. When all four monomers mimicked constitutive phosphorylation (AQP2-S256D), diffusion was faster than when all four were non-phosphorylated (AQP2-S256A). AQP2-WT diffused at a speed similar to that of AQP2-S256D. When an average of two or three monomers in the tetramer were constitutively phosphorylated, the average diffusion coefficients were not significantly different to that of AQP2-S256D. However, when only one monomer was phosphorylated, diffusion was slower and similar to AQP2-S256A. Thus, AQP2 with two to four phosphorylated monomers has faster plasma membrane kinetics, than the tetramer which contains just one or no phosphorylated monomers. This difference in diffusion rate may reflect behavior of AQP2 tetramers destined for either plasma membrane retention or endocytosis.
Collapse
Affiliation(s)
- Eva C Arnspang
- Department of Clinical Medicine, Aarhus University, DK-8000 Aarhus C, Denmark.
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Frédéric H Login
- Department of Clinical Medicine, Aarhus University, DK-8000 Aarhus C, Denmark.
| | - Jennifer S Koffman
- Department of Interdisciplinary Nanoscience Center, Aarhus University, DK-8000 Aarhus C, Denmark.
| | - Prabuddha Sengupta
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Lene N Nejsum
- Department of Clinical Medicine, Aarhus University, DK-8000 Aarhus C, Denmark.
| |
Collapse
|
17
|
Bae EH, Joo SY, Ma SK, Lee J, Kim SW. Resveratrol attenuates 4-hydroxy-2-hexenal-induced oxidative stress in mouse cortical collecting duct cells. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2016; 20:229-36. [PMID: 27162476 PMCID: PMC4860364 DOI: 10.4196/kjpp.2016.20.3.229] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 12/17/2015] [Accepted: 02/15/2016] [Indexed: 01/02/2023]
Abstract
Resveratrol (RSV) may provide numerous protective eff ects against chronic inflammatory diseases. Due to local hypoxia and hypertonicity, the renal medulla is subject to extreme oxidative stress, and aldehyde products formed during lipid peroxidation, such as 4-hydroxy-2-hexenal (HHE), might be responsible for tubular injury. This study aimed at investigating the eff ects of RSV on renal and its signaling mechanisms. While HHE treatment resulted in decreased expression of Sirt1, AQP2, and nuclear factor erythroid 2-related factor 2 (Nrf2), mouse cortical collecting duct cells (M1) cells treated with HHE exhibited increased activation of p38 MAPK, extracellular signal regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and increased expression of NOX4, p47phox, Kelch ECH associating protein 1 (Keap1) and COX2. HHE treatment also induced NF-κB activation by promoting IκB-α degradation. Meanwhile, the observed increases in nuclear NF-κB, NOX4, p47phox, and COX2 expression were attenuated by treatment with Bay 117082, N-acetyl-l-cysteine (NAC), or RSV. Our findings indicate that RSV inhibits the expression of inflammatory proteins and the production of reactive oxygen species in M1 cells by inhibiting NF-κB activation.
Collapse
Affiliation(s)
- Eun Hui Bae
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju 61469, Korea
| | - Soo Yeon Joo
- Department of Physiology, Chonnam National University Medical School, Gwangju 61469, Korea
| | - Seong Kwon Ma
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju 61469, Korea
| | - JongUn Lee
- Department of Physiology, Chonnam National University Medical School, Gwangju 61469, Korea
| | - Soo Wan Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju 61469, Korea
| |
Collapse
|
18
|
Muhl L, Moessinger C, Adzemovic MZ, Dijkstra MH, Nilsson I, Zeitelhofer M, Hagberg CE, Huusko J, Falkevall A, Ylä-Herttuala S, Eriksson U. Expression of vascular endothelial growth factor (VEGF)-B and its receptor (VEGFR1) in murine heart, lung and kidney. Cell Tissue Res 2016; 365:51-63. [DOI: 10.1007/s00441-016-2377-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 02/11/2016] [Indexed: 12/31/2022]
|
19
|
Ortiz MC, Albertoni Borghese MF, Balonga SE, Lavagna A, Filipuzzi AL, Elesgaray R, Costa MA, Majowicz MP. Renal response to L-arginine in diabetic rats. A possible link between nitric oxide system and aquaporin-2. PLoS One 2014; 9:e104923. [PMID: 25111608 PMCID: PMC4128736 DOI: 10.1371/journal.pone.0104923] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 07/15/2014] [Indexed: 11/18/2022] Open
Abstract
The aim of this study was to evaluate whether L-Arginine (L-Arg) supplementation modifies nitric oxide (NO) system and consequently aquaporin-2 (AQP2) expression in the renal outer medulla of streptozotocin-diabetic rats at an early time point after induction of diabetes. Male Wistar rats were divided in four groups: Control, Diabetic, Diabetic treated with L-Arginine and Control treated with L-Arginine. Nitric oxide synthase (NOS) activity was estimated by [14C] L-citrulline production in homogenates of the renal outer medulla and by NADPH-diaphorase staining in renal outer medullary tubules. Western blot was used to detect the expression of AQP2 and NOS types I and III; real time PCR was used to quantify AQP2 mRNA. The expression of both NOS isoforms, NOS I and NOS III, was decreased in the renal outer medulla of diabetic rats and L-Arg failed to prevent these decreases. However, L-Arg improved NO production, NADPH-diaphorase activity in collecting ducts and other tubular structures, and NOS activity in renal homogenates from diabetic rats. AQP2 protein and mRNA were decreased in the renal outer medulla of diabetic rats and L-Arg administration prevented these decreases. These results suggest that the decreased NOS activity in collecting ducts of the renal outer medulla may cause, at least in part, the decreased expression of AQP2 in this model of diabetes and constitute additional evidence supporting a role for NO in contributing to renal water reabsorption through the modulation of AQP2 expression in this pathological condition. However, we cannot discard that another pathway different from NOS also exists that links L-Arg to AQP2 expression.
Collapse
Affiliation(s)
- María C Ortiz
- Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. Buenos Aires, Argentina
| | - María F Albertoni Borghese
- Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. Buenos Aires, Argentina
| | - Sabrina E Balonga
- Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. Buenos Aires, Argentina
| | - Agustina Lavagna
- Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. Buenos Aires, Argentina
| | - Ana L Filipuzzi
- Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. Buenos Aires, Argentina
| | - Rosana Elesgaray
- Cátedra de Fisiología, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. Buenos Aires, Argentina
| | - María A Costa
- Cátedra de Fisiología, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. Buenos Aires, Argentina
| | - Mónica P Majowicz
- Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. Buenos Aires, Argentina
| |
Collapse
|
20
|
Michałek K, Laszczyńska M, Ciechanowicz AK, Herosimczyk A, Rotter I, Oganowska M, Lepczyński A, Dratwa-Chałupnik A. Immunohistochemical identification of aquaporin 2 in the kidneys of young beef cattle. Biotech Histochem 2013; 89:342-7. [PMID: 24325682 DOI: 10.3109/10520295.2013.858828] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aquaporin 2 (AQP2) is a small, integral tetrameric plasma membrane protein that is expressed in mammalian kidneys. The specific constitution of this protein and its selective permeability to water means that AQP2 plays an important role in hypertonic urine production. Immunolocalization of AQP2 has been studied in humans, monkeys, sheep, dogs, rabbits, rats, mice and adult cattle. We analyzed the expression of AQP2 in kidneys of 7-month-old Polish-Friesian var. black and white male calves. AQP2 was localized in the principal cells of collecting ducts in medullary rays penetrating the renal cortex and in the collecting ducts of renal medulla. AQP2 was expressed most strongly in the apical plasma membrane, but expression was observed also in the intracellular vesicles and basolateral plasma membrane. Our study provides new information concerning the immunolocalization of AQP2 in calf kidneys.
Collapse
Affiliation(s)
- K Michałek
- Department of Physiology, Cytobiology and Proteomics, Faculty of Biotechnology and Animal Husbandry, West Pomeranian University of Technology , Doktora Judyma Str. 6, 71-466
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Day RE, Kitchen P, Owen DS, Bland C, Marshall L, Conner AC, Bill RM, Conner MT. Human aquaporins: regulators of transcellular water flow. Biochim Biophys Acta Gen Subj 2013; 1840:1492-506. [PMID: 24090884 DOI: 10.1016/j.bbagen.2013.09.033] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 09/19/2013] [Accepted: 09/23/2013] [Indexed: 02/06/2023]
Abstract
BACKGROUND Emerging evidence supports the view that (AQP) aquaporin water channels are regulators of transcellular water flow. Consistent with their expression in most tissues, AQPs are associated with diverse physiological and pathophysiological processes. SCOPE OF REVIEW AQP knockout studies suggest that the regulatory role of AQPs, rather than their action as passive channels, is their critical function. Transport through all AQPs occurs by a common passive mechanism, but their regulation and cellular distribution varies significantly depending on cell and tissue type; the role of AQPs in cell volume regulation (CVR) is particularly notable. This review examines the regulatory role of AQPs in transcellular water flow, especially in CVR. We focus on key systems of the human body, encompassing processes as diverse as urine concentration in the kidney to clearance of brain oedema. MAJOR CONCLUSIONS AQPs are crucial for the regulation of water homeostasis, providing selective pores for the rapid movement of water across diverse cell membranes and playing regulatory roles in CVR. Gating mechanisms have been proposed for human AQPs, but have only been reported for plant and microbial AQPs. Consequently, it is likely that the distribution and abundance of AQPs in a particular membrane is the determinant of membrane water permeability and a regulator of transcellular water flow. GENERAL SIGNIFICANCE Elucidating the mechanisms that regulate transcellular water flow will improve our understanding of the human body in health and disease. The central role of specific AQPs in regulating water homeostasis will provide routes to a range of novel therapies. This article is part of a Special Issue entitled Aquaporins.
Collapse
Affiliation(s)
- Rebecca E Day
- Biomedical Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, UK
| | - Philip Kitchen
- Molecular Organisation and Assembly in Cells Doctoral Training Centre, University of Warwick, Coventry CV4 7AL, UK
| | - David S Owen
- Biomedical Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, UK
| | - Charlotte Bland
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Lindsay Marshall
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Alex C Conner
- School of Clinical and Experimental Medicine, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
| | - Roslyn M Bill
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK.
| | - Matthew T Conner
- Biomedical Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, UK.
| |
Collapse
|
22
|
Aquaporin-3 and aquaporin-4 are sorted differently and separately in the trans-Golgi network. PLoS One 2013; 8:e73977. [PMID: 24058510 PMCID: PMC3776795 DOI: 10.1371/journal.pone.0073977] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 08/01/2013] [Indexed: 11/19/2022] Open
Abstract
Aquaporin-3 (AQP3) and aquaporin-4 (AQP4) are homologous proteins expressed in the basolateral plasma membrane of kidney collecting duct principal cells, where they mediate the exit pathway for apically reabsorbed water. Although both proteins are localized to the same plasma membrane domain, it is unknown if they are sorted together in the Golgi, or arrive in the same or different vesicles at the plasma membrane. We addressed these questions using high resolution deconvolution imaging, spinning disk and laser scanning confocal microscopy of cells expressing AQP3 and AQP4. AQP3 and AQP4 were observed mostly in separate post-Golgi carriers, and spinning disk microscopy showed that most of AQP3 and AQP4 were delivered to the plasma membrane in separate vesicles. In contrast, VSV-G and LDL-R, two well-charcterized basolateral proteins, co-localized to a high degree in the same post-Golgi carriers, indicating that the differential sorting of AQP3 and AQP4 is specific and regulated. Significantly, a chimeric AQP3 containing the AQP4 cytoplasmic tails co-localized with AQP4 in post-Golgi vesicles. These results indicate that AQP3 and AQP4 are separated into different post-Golgi carriers based on different cytoplasmic domain sorting signals, and are then delivered separately to the plasma membrane.
Collapse
|
23
|
Chung JS, Maurer L, Bratcher M, Pitula JS, Ogburn MB. Cloning of aquaporin-1 of the blue crab, Callinectes sapidus: its expression during the larval development in hyposalinity. AQUATIC BIOSYSTEMS 2012; 8:21. [PMID: 22943628 PMCID: PMC3489796 DOI: 10.1186/2046-9063-8-21] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 07/25/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Ontogenetic variation in salinity adaptation has been noted for the blue crab, Callinectes sapidus, which uses the export strategy for larval development: females migrate from the estuaries to the coast to spawn, larvae develop in the ocean, and postlarvae (megalopae) colonize estuarine areas. We hypothesized that C. sapidus larvae may be stenohaline and have limited osmoregulatory capacity which compromises their ability to survive in lower salinity waters. We tested this hypothesis using hatchery-raised larvae that were traceable to specific life stages. In addition, we aimed to understand the possible involvement of AQP-1 in salinity adaptation during larval development and during exposure to hyposalinity. RESULTS A full-length cDNA sequence of aquaporin (GenBank JQ970426) was isolated from the hypodermis of the blue crab, C. sapidus, using PCR with degenerate primers and 5' and 3' RACE. The open reading frame of CasAQP-1 consists of 238 amino acids containing six helical structures and two NPA motifs for the water pore. The expression pattern of CasAQP-1 was ubiquitous in cDNAs from all tissues examined, although higher in the hepatopancreas, thoracic ganglia, abdominal muscle, and hypodermis and lower in the antennal gland, heart, hemocytes, ovary, eyestalk, brain, hindgut, Y-organs, and gill. Callinectes larvae differed in their capacity to molt in hyposalinity, as those at earlier stages from Zoea (Z) 1 to Z4 had lower molting rates than those from Z5 onwards, as compared to controls kept in 30 ppt water. No difference was found in the survival of larvae held at 15 and 30 ppt. CasAQP-1 expression differed with ontogeny during larval development, with significantly higher expression at Z1-2, compared to other larval stages. The exposure to 15 ppt affected larval-stage dependent CasAQP-1 expression which was significantly higher in Z2- 6 stages than the other larval stages. CONCLUSIONS We report the ontogenetic variation in CasAQP-1 expression during the larval development of C. sapidus and the induction of its expression at early larval stages in the exposure of hyposalinity. However, it remains to be determined if the increase in CasAQP-1 expression at later larval stages may have a role in adaptation to hyposalinity.
Collapse
Affiliation(s)
- J Sook Chung
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 East Pratt Street, Columbus Center, Suite 236, Baltimore, MD, USA
| | - Leah Maurer
- Department of Environmental Science, University of Maryland Baltimore County, Baltimore, MD, USA
| | - Meagan Bratcher
- Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD, USA
| | - Joseph S Pitula
- Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD, USA
| | - Matthew B Ogburn
- Department of Natural Sciences, Savannah State University, Savannah, GA, USA
| |
Collapse
|
24
|
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.
Collapse
Affiliation(s)
- G Tamma
- Department of Biosciences, Biotechnologies and Pharmacological Sciences, University of Bari, Italy
| | | | | | | |
Collapse
|
25
|
Cutler CP, Harmon S, Walsh J, Burch K. Characterization of Aquaporin 4 Protein Expression and Localization in Tissues of the Dogfish (Squalus acanthias). Front Physiol 2012; 3:21. [PMID: 22363294 PMCID: PMC3279706 DOI: 10.3389/fphys.2012.00021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 01/29/2012] [Indexed: 11/13/2022] Open
Abstract
The role of aquaporin water channels such as aquaporin 4 (Aqp4) in elasmobranchs such as the dogfish Squalus acanthias is completely unknown. This investigation set out to determine the expression and cellular and sub-cellular localization of Aqp4 protein in dogfish tissues. Two polyclonal antibodies were generated (AQP4/1 and AQP4/2) and these showed somewhat different characteristics in Western blotting and immunohistochemistry. Western blots using the AQP4/1 antibody showed two bands (35.5 and 49.5 kDa) in most tissues in a similar fashion to mammals. Liver had an additional band of 57 kDa and rectal gland two further faint bands of 37.5 and 38.5 kDa. However, unlike in mammals, Aqp4 protein was ubiquitously expressed in all tissues including gill and liver. The AQP4/2 antibody appeared much less specific in Western blots. Both antibodies were used in immunohistochemistry and showed similar cellular localizations, although the AQP4/2 antibody had a more restricted sub-cellular distribution compared to AQP4/1 and therefore appeared to be more specific for Aqp4. In kidney a sub-set of tubules were stained which may represent intermediate tubule segments (In-III-In-VI). AQP4/1 and AQP4/2 antibodies localized to the same tubules segments in serial sections although the intensity and sub-cellular distribution were different. AQP4/2 showed a basal or basolateral membrane distribution whereas AQP4/1 was often distributed throughout the whole cell including the nuclear region. In rectal gland and cardiac stomach Aqp4 was localized to secretory tubules but again AQP/1 and AQP/2 exhibited different sub-cellular distributions. In gill, both antibodies stained large cells in the primary filament and secondary lamellae. Again AQP4/1 antibody stained most or all the cell including the nucleus, whereas AQP4/2 had a plasma membrane or plasma membrane and cytoplasmic distribution. Two types of large mitochondrial rich transport cells are known to exist in elasmobranchs, that express either Na, K-ATPase, or V-type ATPase ion transporters. Using Na, K-ATPase, and V-type ATPase antibodies, Aqp4 was colocalized with these proteins using the AQP4/1 antibody. Results show Aqp4 is expressed in both (and all) branchial Na, K-ATPase, and V-type ATPase expressing cells.
Collapse
|
26
|
Cutler CP, Maciver B, Cramb G, Zeidel M. Aquaporin 4 is a Ubiquitously Expressed Isoform in the Dogfish (Squalus acanthias) Shark. Front Physiol 2012; 2:107. [PMID: 22291652 PMCID: PMC3254168 DOI: 10.3389/fphys.2011.00107] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Accepted: 12/05/2011] [Indexed: 01/22/2023] Open
Abstract
The dogfish ortholog of aquaporin 4 (AQP4) was amplified from cDNA using degenerate PCR followed by cloning and sequencing. The complete coding region was then obtained using 5' and 3' RACE techniques. Alignment of the sequence with AQP4 amino acid sequences from other species showed that dogfish AQP4 has high levels (up to 65.3%) of homology with higher vertebrate sequences but lower levels of homology to Agnathan (38.2%) or teleost (57.5%) fish sequences. Northern blotting indicated that the dogfish mRNA was approximately 3.2 kb and was highly expressed in the rectal gland (a shark fluid secretory organ). Semi-quantitative PCR further indicates that AQP4 is ubiquitous, being expressed in all tissues measured but at low levels in certain tissues, where the level in liver > gill > intestine. Manipulation of the external environmental salinity of groups of dogfish showed that when fish were acclimated in stages to 120% seawater (SW) or 75% SW, there was no change in AQP4 mRNA expression in either rectal gland, kidney, or esophagus/cardiac stomach. Whereas quantitative PCR experiments using the RNA samples from the same experiment, showed a significant 63.1% lower abundance of gill AQP4 mRNA expression in 120% SW-acclimated dogfish. The function of dogfish AQP4 was also determined by measuring the effect of the AQP4 expression in Xenopus laevis oocytes. Dogfish AQP4 expressing-oocytes, exhibited significantly increased osmotic water permeability (P(f)) compared to controls, and this was invariant with pH. Permeability was not significantly reduced by treatment of oocytes with mercury chloride, as is also the case with AQP4 in other species. Similarly AQP4 expressing-oocytes did not exhibit enhanced urea or glycerol permeability, which is also consistent with the water-selective property of AQP4 in other species.
Collapse
|
27
|
Le IP, Schultz S, Andresen BT, Dewey GL, Zhao P, Listenberger L, Deen PM, Buchwalter A, Barney CC, Burnatowska-Hledin MA. Aquaporin-2 Levelsin vitroandin vivoare Regulated by VACM-1, a Cul 5 Gene. Cell Physiol Biochem 2012; 30:1148-58. [DOI: 10.1159/000343305] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2012] [Indexed: 11/19/2022] Open
|
28
|
Procino G, Mastrofrancesco L, Sallustio F, Costantino V, Barbieri C, Pisani F, Schena FP, Svelto M, Valenti G. AQP5 is expressed in type-B intercalated cells in the collecting duct system of the rat, mouse and human kidney. Cell Physiol Biochem 2011; 28:683-92. [PMID: 22178880 DOI: 10.1159/000335762] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2011] [Indexed: 12/27/2022] Open
Abstract
We screened human kidney-derived multipotent CD133+/CD24+ ARPCs for the possible expression of all 13 aquaporin isoforms cloned in humans. Interestingly, we found that ARPCs expressed both AQP5 mRNA and mature protein. This novel finding prompted us to investigate the presence of AQP5 in situ in kidney. We report here the novel finding that AQP5 is expressed in human, rat and mouse kidney at the apical membrane of type-B intercalated cells. AQP5 is expressed in the renal cortex and completely absent from the medulla. Immunocytochemical analysis using segment- and cell type-specific markers unambiguously indicated that AQP5 is expressed throughout the collecting system at the apical membrane of type-B intercalated cells, where it co-localizes with pendrin. No basolateral AQPs were detected in type-B intercalated cells, suggesting that AQP5 is unlikely to be involved in the net trans-epithelial water reabsorption occurring in the distal tubule. An intriguing hypothesis is that AQP5 may serve an osmosensor for the composition of the fluid coming from the thick ascending limb. Future studies will unravel the physiological role of AQP5 in the kidney.
Collapse
Affiliation(s)
- Giuseppe Procino
- Department of General and Environmental Physiology, University of Bari, Via Amendola 165/A, Bari, Italy.
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Hadchouel J, Büsst C, Procino G, Valenti G, Chambrey R, Eladari D. Regulation of extracellular fluid volume and blood pressure by pendrin. Cell Physiol Biochem 2011; 28:505-12. [PMID: 22116364 DOI: 10.1159/000335116] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2011] [Indexed: 01/11/2023] Open
Abstract
Na(+) is commonly designed as the culprit of salt-sensitive hypertension but several studies suggest that abnormal Cl(-) transport is in fact the triggering mechanism. This review focuses on the regulation of blood pressure (BP) by pendrin, an apical Cl(-)/HCO(3)(-) exchanger which mediates HCO(3)(-) secretion and transcellular Cl(-) transport in type B intercalated cells (B-ICs) of the distal nephron. Studies in mice showed that it is required not only for acid-base regulation but also for BP regulation as pendrin knock-out mice develop hypotension when submitted to NaCl restriction and are resistant to aldosterone-induced hypertension. Pendrin contributes to these processes by two mechanisms. First, pendrin-mediated Cl(-) transport is coupled with Na(+) reabsorption by the Na(+)-dependent Cl(-)/HCO(3)(-) exchanger NDCBE to mediate NaCl reabsorption in B-ICs. Second, pendrin activity regulates Na(+) reabsorption by the adjacent principal cells, possibly by interaction with the ATP-mediated paracrine signalling recently identified between ICs and principal cells. Interestingly, the water channel AQP5 was recently found to be expressed at the apical side of B-ICs, in the absence of a basolateral water channel, and pendrin and AQP5 membrane expressions are both inhibited by K(+) depletion, suggesting that pendrin and AQP5 could cooperate to regulate cell volume, a potent stimulus of ATP release.
Collapse
Affiliation(s)
- Juliette Hadchouel
- INSERM UMRS 970-Paris Cardiovascular Research Center (PARCC), Paris, France
| | | | | | | | | | | |
Collapse
|
30
|
Albertoni Borghese MF, Bettini LM, Nitta CH, de Frutos S, Majowicz M, Gonzalez Bosc LV. Aquaporin-2 promoter is synergistically regulated by nitric oxide and nuclear factor of activated T cells. NEPHRON EXTRA 2011; 1:124-38. [PMID: 22470386 PMCID: PMC3290856 DOI: 10.1159/000333066] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Background/Aims We have previously shown that aquaporin-2 (AQP2) is down-regulated in the renal medulla of rats made hypertensive by chronic inhibition of nitric oxide synthase. It has been shown that AQP2 expression is regulated by the calcineurin/nuclear factor of activated T cells (NFATc). Nitric oxide (NO) regulates the activity of NFATc via c-Jun-N-terminal kinase 2 (JNK2). Therefore, we hypothesized that increases in NO enhance NFATc-mediated up-regulation of AQP2 promoter activity. Methods AQP2 mRNA and protein expression were detected in mouse renal papilla. AQP2 promoter luciferase reporter- and NFAT luciferase reporter-transfected MDCK cells were used to determine AQP2 promoter activity and NFATc activity, respectively. Cells were incubated with classic activators and inhibitors of NFATc and the NO pathway. Results Our results demonstrate that both Ca2+ and NO have a synergistic effect resulting in an increase in AQP2 mRNA and protein in mouse papilla and activation of the AQP2 promoter in kidney-derived cells. In addition, NO enhances Ca2+-induced NFATc activation. The underlying mechanism involves increased NFATc nuclear import and decreased export via protein kinase G-mediated inhibition of JNK1/2. Conclusions This is the first study defining novel regulatory roles for NO and NFATc in the control of AQP2, which is an important renal protein.
Collapse
Affiliation(s)
- María F Albertoni Borghese
- Biología Celular y Molecular, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | | | | | | | | |
Collapse
|
31
|
Satake M, Ikarashi N, Kagami M, Ogiue N, Toda T, Kobayashi Y, Ochiai W, Sugiyama K. Increases in the expression levels of aquaporin-2 and aquaporin-3 in the renal collecting tubules alleviate dehydration associated with polyuria in diabetes mellitus. Biol Pharm Bull 2011; 33:1965-70. [PMID: 21139234 DOI: 10.1248/bpb.33.1965] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Enhanced expression of renal aquaporin-2 (AQP2) has been reported when polyuria occurs in diabetic animal models. The purpose of this study was to clarify the possibility that increased AQP2 expression in the kidneys play a role as a compensatory mechanism to alleviate diabetic dehydration. Lithium carbonate (Li₂CO₃), which decreases the renal expression of AQPs, was administered to streptozotocin (STZ)-induced model mice of type I diabetes mellitus (STZ mice), to investigate the relationship between urine volume and renal AQP expression. Plasma glucose and urine glucose levels were similar between STZ mice given feed containing Li₂CO₃ for 10 d and un-treated STZ mice. Urine volume increased to 70 ml/d for the Li₂CO₃-treated STZ mice, compared to 36 ml/d for un-treated STZ mice. No changes were observed in creatinine clearance or the mRNA expression levels of sodium myo-inositol transporter and taurine transporter, which are genes associated with the regulation of osmotic pressure in the kidney, in the Li₂CO₃-treated STZ mice relative to un-treated STZ mice. Protein expression levels of AQP2 and aquaporin-3 (AQP3) of the renal inner medulla were significantly decreased in the Li₂CO₃-treated STZ mice, compared to levels in the STZ group. This study revealed that the decreased expression levels of AQP2 and AQP3 in the kidney increased the urine volume in mice without a change in urinary osmotic pressure. The results of this study suggest that the increased renal AQP2 and AQP3 expression, in the setting of polyuria, physiologically serves as a compensatory mechanism to alleviate dehydration in diabetes mellitus.
Collapse
Affiliation(s)
- Masako Satake
- Department of Clinical Pharmacokinetics, Hoshi University, Tokyo, Japan
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Abstract
Thiazide diuretics are one of the most widely used and cost-effective classes of antihypertensive agents worldwide. Thiazides however have a significant side effect profile and are frequently insufficient to normalize blood pressure alone. Thiazide-induced hyponatraemia (TIH) is a major adverse effect, affecting up to one in seven patients receiving these drugs. TIH is more common in females, the elderly and those of low body weight and may cause symptoms such as confusion, falls and seizures. It is a common cause of hospital admission in the elderly. Although TIH occurs at least as frequently as hypokalaemia, much less is understood about the mechanism by which this occurs. Thiazides lower blood pressure by reducing the reabsorption of sodium from the distal nephron by inhibition of the NaCl cotransporter. The molecular mechanism by which this occurs together with the little known role of thiazides in regulating water reabsorbtion from the collecting ducts is discussed and the relevance to TIH evaluated. TIH is highly reproducible by thiazide rechallenge suggesting there may be a genetic predisposition. Both targeted resequencing of candidate genes and genome wide association techniques offer promising strategies by which such genetic contributions may be investigated. The rewards for uncovering the molecular mechanisms underlying TIH and the regulation of distal nephron sodium and water absorption are significant; not only could it inform the design of better tolerated, more efficacious thiazide-like antihypertensive agents but it may also facilitate the pharmacogenomic profiling of hypertensive patients to avoid thiazides in those likely to suffer adverse effects.
Collapse
Affiliation(s)
- Mark Glover
- Division of Therapeutics and Molecular Medicine, University of Nottingham, Nottingham, United Kingdom.
| | | |
Collapse
|
33
|
Li Y, Zelenina M, Plat-Willson G, Marcoux MO, Aperia A, Casper C. Urinary aquaporin-2 excretion during ibuprofen or indomethacin treatment in preterm infants with patent ductus arteriosus. Acta Paediatr 2011; 100:59-66. [PMID: 21143292 DOI: 10.1111/j.1651-2227.2010.01943.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM Water channel AQP2 is the target for vasopressin (AVP) and a major determinant of urinary concentrating capacity. In mature kidneys, prostaglandins counteract the effect of AVP on AQP2 expression at functional sites. We investigated whether disturbances in water homeostasis in infants with patent ductus arteriosus (PDA) treated with prostaglandin inhibitors can be attributed to activation of AQP2. METHODS In 53 infants with symptomatic PDA (gestational age 24-33 weeks), 30 receiving ibuprofen and 23 indomethacin starting at 2-15 days of life, clinical and biochemical data were collected before treatment and after each dose of the drugs. Urinary AQP2 was determined by dot immunoblotting. RESULTS Urinary AQP2 level and osmolality were decreased in both groups. Urinary osmolality was overall low and correlated inversely with fluid uptake. In ibuprofen group, there was no correlation of AQP2 level with urinary osmolality. CONCLUSION There was no AQP2 upregulation in the infants. The low urinary osmolality and dissociation between urinary osmolality and urinary AQP2 level indicate that the fluid retention sometimes observed in PDA infants treated with prostaglandin inhibitors is not caused by increased levels of functional AQP2. Thus, knowledge about the renal physiology of the adult cannot always be transferred to the infant kidney.
Collapse
Affiliation(s)
- Yanhong Li
- Nordic Centre of Excellence for Research in Water Imbalance Related Disorders, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | | | | | | | | | | |
Collapse
|
34
|
Aburada T, Ikarashi N, Kagami M, Ichikawa Y, Sugitani M, Maniwa A, Ueda H, Toda T, Ito K, Ochiai W, Matsushita R, Miyamoto KI, Sugiyama K. Byakkokaninjinto prevents body water loss by increasing the expression of kidney aquaporin-2 and skin aquaporin-3 in KKAy mice. Phytother Res 2010; 25:897-903. [DOI: 10.1002/ptr.3358] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 10/18/2010] [Accepted: 10/19/2010] [Indexed: 01/17/2023]
|
35
|
The role of renal aquaporin 2 in the alleviation of dehydration associated with diabetic polyuria in KKAy mice. Life Sci 2010; 87:475-80. [DOI: 10.1016/j.lfs.2010.09.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 08/20/2010] [Accepted: 08/24/2010] [Indexed: 11/23/2022]
|
36
|
An JL, Ishida Y, Kimura A, Kondo T. Forensic application of intrarenal aquaporin-2 expression for differential diagnosis between freshwater and saltwater drowning. Int J Legal Med 2009; 124:99-104. [DOI: 10.1007/s00414-009-0375-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Accepted: 10/01/2009] [Indexed: 12/27/2022]
|
37
|
Oberg F, Ekvall M, Nyblom M, Backmark A, Neutze R, Hedfalk K. Insight into factors directing high production of eukaryotic membrane proteins; production of 13 human AQPs in Pichia pastoris. Mol Membr Biol 2009; 26:215-27. [PMID: 19384754 DOI: 10.1080/09687680902862085] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Membrane proteins are key players in all living cells. To achieve a better understanding of membrane protein function, significant amounts of purified protein are required for functional and structural analyses. Overproduction of eukaryotic membrane proteins, in particular, is thus an essential yet non-trivial task. Hence, improved understanding of factors which direct a high production of eukaryotic membrane proteins is desirable. In this study we have compared the overproduction of all human aquaporins in the eukaryotic host Pichia pastoris. We report quantitated production levels of each homologue and the extent of their membrane localization. Our results show that the protein production levels vary substantially, even between highly homologous aquaporins. A correlation between the extents of membrane insertion with protein function also emerged, with a higher extent of membrane insertion for pure water transporters compared to aquaporin family members with other substrate specificity. Nevertheless, the nucleic acid sequence of the second codon appears to play an important role in overproduction. Constructs containing guanine at the first position of this codon (being part of the mammalian Kozak sequence) are generally produced at a higher level, which is confirmed for hAQP8. In addition, mimicking the yeast consensus sequence (ATGTCT) apparently has a negative influence on the production level, as shown for hAQP1. Moreover, by mutational analysis we show that the yield of hAQP4 can be heavily improved by directing the protein folding pathway as well as stabilizing the aquaporin tetramer.
Collapse
Affiliation(s)
- Fredrik Oberg
- Department of Chemistry/Biochemistry, Göteborg University, Göteborg, Sweden
| | | | | | | | | | | |
Collapse
|
38
|
Benga G. Water channel proteins (later called aquaporins) and relatives: past, present, and future. IUBMB Life 2009; 61:112-33. [PMID: 19165894 DOI: 10.1002/iub.156] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Water channels or water channel proteins (WCPs) are transmembrane proteins that have a specific three-dimensional structure with a pore that can be permeated by water molecules. WCPs are large families (over 450 members) that are present in all kingdoms of life. The first WCP was discovered in the human red blood cell (RBC) membrane in 1980s. In 1990s other WCPs were discovered in plants, microorganisms, various animals, and humans; and it became obvious that the WCPs belong to the superfamily of major intrinsic proteins (MIPs, over 800 members). WCPs include three subfamilies: (a) aquaporins (AQPs), which are water specific (or selective water channels); (b) aquaglyceroporins (and glycerol facilitators), which are permeable to water and/or other small molecules; and (c) "superaquaporins" or subcellular AQPs. WCPs (and MIPs) have several structural characteristics which were better understood after the atomic structure of some MIPs was deciphered. The structure-function relationships of MIPs expressed in microorganisms (bacteria, archaea, yeast, and protozoa), plants, and some multicellular animal species [nematodes, insects, fishes, amphibians, mammals (and humans)] are described. A synthetic overview on the WCPs from RBCs from various species is provided. The physiological roles of WCPs in kidney, gastrointestinal system, respiratory apparatus, central nervous system, eye, adipose tissue, skin are described, and some implications of WCPs in various diseases are briefly presented. References of detailed reviews on each topic are given. This is the first review providing in a condensed form an overview of the whole WCP field that became in the last 20 years a very hot area of research in biochemistry and molecular cell biology, with wide and increasing implications.
Collapse
Affiliation(s)
- Gheorghe Benga
- Department of Cell and Molecular Biology, Iuliu HaTieganu University of Medicine and Pharmacy Cluj-Napoca, Cluj-Napoca, Romania.
| |
Collapse
|
39
|
Hasler U. Controlled aquaporin-2 expression in the hypertonic environment. Am J Physiol Cell Physiol 2009; 296:C641-53. [PMID: 19211910 DOI: 10.1152/ajpcell.00655.2008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The corticomedullary osmolality gradient is the driving force for water reabsorption occurring in the kidney. In the collecting duct, this gradient allows luminal water to move across aquaporin (AQP) water channels, thereby increasing urine concentration. However, this same gradient exposes renal cells to great osmotic challenges. These cells must constantly adapt to fluctuations of environmental osmolality that challenge cell volume and incite functional change. This implies profound alterations of cell phenotype regarding water permeability. AQP2 is an essential component of the urine concentration mechanism whose controlled expression dictates apical water permeability of collecting duct principal cells. This review focuses on changes of AQP2 abundance and trafficking in hypertonicity-challenged cells. Intracellular mechanisms governing these events are discussed and the biological relevance of altered AQP2 expression by hypertonicity is outlined.
Collapse
Affiliation(s)
- Udo Hasler
- Service de Néphrologie, Fondation pour Recherches Médicales, 64 Ave. de la Roseraie, CH-1211, Geneva 4, Switzerland.
| |
Collapse
|
40
|
Hasler U, Leroy V, Jeon US, Bouley R, Dimitrov M, Kim JA, Brown D, Kwon HM, Martin PY, Féraille E. NF-kappaB modulates aquaporin-2 transcription in renal collecting duct principal cells. J Biol Chem 2008; 283:28095-105. [PMID: 18703515 PMCID: PMC2568939 DOI: 10.1074/jbc.m708350200] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 08/14/2008] [Indexed: 11/06/2022] Open
Abstract
Renal tubulo-interstitial inflammation is frequently associated with polyuria and urine concentration defects. This led us to investigate the effects of the major pro-inflammatory nuclear factor kappaB (NF-kappaB) pathway on aquaporin 2 (AQP2) expression by the collecting duct. Using immortalized collecting duct principal cells (mpkCCDcl4), we found that, acting independently of vasopressin, activation of NF-kappaB by lipopolysaccharide (LPS) decreased AQP2 mRNA and protein levels in a time- and dose-dependent manner but did not decrease AQP2 mRNA stability. Consistently, constitutively active IkappaB kinase beta decreased AQP2 expression. The LPS-induced decrease in AQP2 mRNA levels was confirmed in rat kidney slices and was reproduced both under conditions of elevated cAMP concentration and V(2) receptor antagonism. Computer analysis of the AQP2 promoter revealed two putative kappaB elements. Mutation of either kappaB element abolished the LPS-induced decrease of luciferase activity in cells expressing AQP2 promoter-luciferase plasmid constructs. Chromatin immunoprecipitation revealed that LPS challenge decreased p65, increased p50 and p52, and had no effect on RelB and c-Rel binding to kappaB elements of the AQP2 promoter. RNA-mediated interference silencing of p65, p50, and p52 confirmed controlled AQP2 transcription by these NF-kappaB subunits. We additionally found that hypertonicity activated NF-kappaB in mpkCCDcl4 cells, an effect that may counteract the Tonicity-responsive enhancer binding protein (TonEBP)-dependent increase in AQP2 gene transcription. Taken together, these findings indicate that NF-kappaB is an important physiological regulator of AQP2 transcription.
Collapse
Affiliation(s)
- Udo Hasler
- Service de Néphrologie, Fondation pour Recherches Médicales and University of Geneva, CH-1211, Geneva 4, Switzerland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Sugiura K, Aste N, Fujii M, Shimada K, Saito N. Effect of hyperosmotic stimulation on aquaporins gene expression in chick kidney. Comp Biochem Physiol A Mol Integr Physiol 2008; 151:173-9. [PMID: 18621138 DOI: 10.1016/j.cbpa.2008.06.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Revised: 06/18/2008] [Accepted: 06/19/2008] [Indexed: 10/21/2022]
Abstract
Birds can produce hyperosmotic urine, but their renal morphology differs from that of mammals. Recent studies in mammals, suggested that various aquaporins (AQPs) are present in the kidney and play crucial roles in urine production. To elucidate the role of AQPs in the avian kidney, we first examined for the presence of AQP1, 2, 3, 4, 7 and 9 mRNAs in the chick (Gallus gallus) kidney by RT-PCR analysis. Next, we quantified variations of AQPs mRNAs levels in chick kidney after hyperosmotic stimulation (water-deprivation or salt-loading) by real-time RT-PCR analysis. Our study showed that in addition to AQP1, 2, 3, 4 and 7, chick kidney also expressed AQP9 and that hyperosmotic stimulation induced changes in AQPs expression. In particular, water-deprivation increased AQP2 and AQP3 mRNAs levels, whereas salt-loading induced a significant increase in AQP1, AQP2 and AQP9 mRNAs levels. AQP4 and AQP7 mRNA levels were not affected by any hyperosmotic stimulation. Taken together, these results indicated that the presence of AQPs in chick kidney is similar to that in mammals, that the chick kidney has an additional AQP9 and that AQP1, 2, 3 and 9 may play a crucial but different role in water permeability in this organ.
Collapse
Affiliation(s)
- K Sugiura
- Laboratory of Animal Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | | | | | | | | |
Collapse
|
42
|
Magni F, Chinello C, Raimondo F, Mocarelli P, Kienle MG, Pitto M. AQP1 expression analysis in human diseases: implications for proteomic characterization. Expert Rev Proteomics 2008; 5:29-43. [PMID: 18282122 DOI: 10.1586/14789450.5.1.29] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Aquaporin (AQP)1 belongs to a ubiquitous family of water channel proteins characterized by sequence similarity and the presence of two NPA (Asp-Pro-Ala) motifs existing in almost all organs and tissues. Currently, 13 human AQPs are known and they are divided into two subgroups according to their ability to transport only water molecules, such as AQP1, or also glycerol and other small solutes. The genomic, structural and functional aspects of AQP1 are briefly described. An in-depth discussion is devoted to proteomic approaches that are useful for identifying and characterizing AQP1, mainly through electrophoretic techniques combined with different extraction procedures followed by mass spectrometry analysis. Moreover, the relevance of AQP1 in human diseases is also explained. Its role in human tumors and, in particular, those of the kidney (e.g., clear cell renal carcinoma) is discussed.
Collapse
Affiliation(s)
- Fulvio Magni
- Department of Experimental Medicine, Faculty of Medicine, Via Cadore 48, 20052 Monza, Italy.
| | | | | | | | | | | |
Collapse
|
43
|
Li YF, Liu JG. Change of renal aquaporin 3 expression in rats after release of obstructive jaundice and its significance. Shijie Huaren Xiaohua Zazhi 2008; 16:517-521. [DOI: 10.11569/wcjd.v16.i5.517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the change of renal aquaporin 3 (AQP3) expression in rats after release of obstructive jaundice in biliary tract and its significance.
METHODS: Fifty Wistar rats were divided into control group (n = 10) and experimental group (n = 40). A model of experimental obstructive jaundice was established. Seven days after release of obstructive jaundice, serum biochemical parameters were detected. Rats in the experimental group were randomly divided into five subgroups: OJ 0 h, OJ 24 h, OJ 72 h, OJ 1 wk and non-operated control (NC). Biochemical parameters in venous blood were detected and the expression level of renal AQP3 was determined by Western blot.
RESULTS: The TBIL and ALT gradually decreased after release of obstructive jaundice in biliary tract (TBIL: 93.26 ± 1.32 vs 63.31 ± 1.85, 30.78 ± 1.40, 5.04 ± 0.24, P < 0.05; ALT: 70.95 ± 1.22 vs 69.96 ± 0.82, 30.74 ± 1.52, 11.84 ± 1.12, P < 0.05). There was no significant difference in levels of BUN and Cr between the OJ 0 h and NC subgroups, but the expression level of AQP3 was lower in the OJ 0 h subgroup than in the NC subgroup. Both BUN and Cr were significantly decreased 24 h after operation and the expression of AQP3 was further decreased. The levels of BUN and Cr did not markedly change between the OJ 24 h and OJ 72 h subgroups. The expression level of AQP3 was slightly higher, but still lower in the OJ 24 h subgroup than in the NC subgroup (P < 0.05). The expression levels of BUN, Cr and AQP3 were not significantly different between the two groups 7 days after operation.
CONCLUSION: The renal function is further damaged after release of obstructive jaundice in biliary tract. The expression level of AQP3 becomes higher when renal function improves. The sensitivity and specificity of AQP3 are higher than those of BUN and Cr.
Collapse
|
44
|
Fenton RA, Knepper MA. Mouse models and the urinary concentrating mechanism in the new millennium. Physiol Rev 2007; 87:1083-112. [PMID: 17928581 DOI: 10.1152/physrev.00053.2006] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Our understanding of urinary concentrating and diluting mechanisms at the end of the 20th century was based largely on data from renal micropuncture studies, isolated perfused tubule studies, tissue analysis studies and anatomical studies, combined with mathematical modeling. Despite extensive data, several key questions remained to be answered. With the advent of the 21st century, a new approach, transgenic and knockout mouse technology, is providing critical new information about urinary concentrating processes. The central goal of this review is to summarize findings in transgenic and knockout mice pertinent to our understanding of the urinary concentrating mechanism, focusing chiefly on mice in which expression of specific renal transporters or receptors has been deleted. These include the major renal water channels (aquaporins), urea transporters, ion transporters and channels (NHE3, NKCC2, NCC, ENaC, ROMK, ClC-K1), G protein-coupled receptors (type 2 vasopressin receptor, prostaglandin receptors, endothelin receptors, angiotensin II receptors), and signaling molecules. These studies shed new light on several key questions concerning the urinary concentrating mechanism including: 1) elucidation of the role of water absorption from the descending limb of Henle in countercurrent multiplication, 2) an evaluation of the feasibility of the passive model of Kokko-Rector and Stephenson, 3) explication of the role of inner medullary collecting duct urea transport in water conservation, 4) an evaluation of the role of tubuloglomerular feedback in maintenance of appropriate distal delivery rates for effective regulation of urinary water excretion, and 5) elucidation of the importance of water reabsorption in the connecting tubule versus the collecting duct for maintenance of water balance.
Collapse
Affiliation(s)
- Robert A Fenton
- Water and Salt Research Center, Institute of Anatomy, University of Aarhus, Aarhus, Denmark.
| | | |
Collapse
|
45
|
Albertoni Borghese MF, Majowicz MP, Ortiz MC, Delgado MF, Sterin Speziale NB, Vidal NA. Renal sodium-glucose cotransporter activity and aquaporin-2 expression in rat kidney during chronic nitric oxide synthase inhibition. Nephron Clin Pract 2007; 107:p77-86. [PMID: 17940347 DOI: 10.1159/000109822] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Accepted: 07/01/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The renal sodium glucose cotransporter (SGLT2) and the water channel aquaporin-2 (AQP2) play a critical role in tubular sodium and water reabsorption and in the regulation of extracellular fluid volume both in physiologic and pathophysiologic conditions. However, there is little information about SGLT2 and AQP2 expression and/or activity in hypertension and there are no reports during hypertension induced by chronic nitric oxide synthase (NOS) inhibition. METHODS Hypertension was induced in rats by oral administration of N(G)-nitro-L-arginine methyl ester (L-NAME) (20 mg/kg/24 h) for 6 (H6) or 12 (H12) weeks. SGLT2 activity was measured using alpha-(14)C-methylglucose active uptake. The expression level of transporters was assessed by immunohistochemistry and/or immunoblotting. RESULTS SGLT2 activity was reduced in both H6 and H12; this was due neither to a decrease in SGLT2 expression nor to a change in membrane phospholipid composition. In H6, AQP2 expression diminished only in the inner medulla (IM), while in H12 it diminished in both outer (OM) and IM. This reduced expression of AQP2 may partially account for the increased urinary volume and decreased urinary osmolality in H12, since we obtained a strong correlation between AQP2 expression and these urinary parameters in both OM and IM. CONCLUSION We propose that in rats in which hypertension is induced by NOS inhibition, SGLT2 activity and AQP2 expression are modified to compensate for the elevated arterial pressure. However, we cannot discount the possibility that the observed changes are due to the decrease in NO production itself.
Collapse
Affiliation(s)
- María F Albertoni Borghese
- Cátedra de Biología Celular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
| | | | | | | | | | | |
Collapse
|
46
|
|
47
|
Wang Y, Chen WM, Gao LL, Liu JG. Dopamine modulates perioperative renal medulla aquaporin 2 expression in experimental obstructive jaundice. Shijie Huaren Xiaohua Zazhi 2007; 15:2714-2717. [DOI: 10.11569/wcjd.v15.i25.2714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the changes in aquaporin 2 expression after bile duct recanalization and the effects of low-dose dopamine on perioperative renal aquaporin 2 expression.
METHODS: Seventy wistar rats were randomly allocated to 4 groups. Sixty rats underwent common bile duct ligation, while the other 10 underwent sham operation. The common duct was ligated on a silicon tube of 2 mm external diameter. Seven days later, the experimental rats were randomly allocated into another 3 groups. Rats in the obstructive jaundice group were injected with 9 g/L normal saline (NS), while those in the other 2 groups were injected with dopamine at 5 or 10 µg/(kg•min), respectively. After 2 h treatment, half in each group were killed and the others were killed 24 h later. Serum was collected from each rat to assess hepatic and renal functions. The right renal medulla was separated and kept at -80℃ until used to measure aquaporin 2 expressions by Western blotting.
RESULTS: In the early period of bile duct recanalization, serum bilirubin levels decreased. There were no significant changes in blood urine or creatine. Renal aquaporin 2 expression was detected by Western blotting. Aquaporin 2 expression in the experimental group treated with dopamine 5 µg/(kg•min) was nearly the same as that in the normal group, both at 0 and 24 h (16 010 ± 646 and 22 715 ± 575 vs 21 966 ± 1544 and 21 917 ± 2661), and better than the group treated with dopamine 10 µg/(kg•min).
CONCLUSION: Low-dose dopamine injection appears to modulate expression of aquaporin 2 in the renal collective tubule epithelium, and to have a positive effect on perioperative renal function in obstructive jaundice.
Collapse
|
48
|
Cutler CP, Phillips C, Hazon N, Cramb G. Cortisol regulates eel (Anguilla anguilla) aquaporin 3 (AQP3) mRNA expression levels in gill. Gen Comp Endocrinol 2007; 152:310-3. [PMID: 17353012 DOI: 10.1016/j.ygcen.2007.01.031] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2006] [Revised: 01/09/2007] [Accepted: 01/12/2007] [Indexed: 11/30/2022]
Abstract
Previous studies in eel (Anguilla anguilla) gill have shown that the expression of the aquaporin 3 (AQP3) water and small solute channel is dramatically decreased (mRNA abundance decreased by up to 97%) when these euryhaline fish are acclimated from freshwater (FW) to seawater (SW). However, AQP3 mRNA expression levels in the intestine following SW-acclimation do not change. The SW-acclimating corticosteroid hormone, cortisol has previously been shown to regulate the expression of aquaporins (particularly AQP1) in eel osmoregulatory tissues in a tissue-specific and isoform-specific fashion. AQP1 is up-regulated in intestine and oesophagus, but down-regulated in kidney, following SW-acclimation in these fish. This study extends knowledge of the regulation of aquaporin expression by cortisol in the eel and shows that elevated levels of this hormone down-regulate AQP3 mRNA expression in the gill in a similar manner to SW-acclimation. However, the smaller magnitude of the changes in branchial AQP3 expression induced by cortisol-infusion (around a 60% decrease), in comparison to those occurring following SW-acclimation, suggest that other factors must also contribute to AQP3 down-regulation. In a similar fashion to the regulation of AQP1 by cortisol, changes in AQP3 expression following hormone infusion appear to be tissue-specific, as little effect was seen on the level of AQP3 expression in the intestine. Again the apparent lack of change in intestinal AQP3 expression following cortisol-infusion mimicked the invariant level of intestinal AQP3 mRNA abundance following SW-acclimation.
Collapse
Affiliation(s)
- C P Cutler
- Department of Biology, Georgia Southern University, Statesboro, GA, USA.
| | | | | | | |
Collapse
|
49
|
Murakami T, Sano F, Huang Y, Komiya A, Baba M, Osada Y, Nagashima Y, Kondo K, Nakaigawa N, Miura T, Kubota Y, Yao M, Kishida T. Identification and characterization of Birt-Hogg-Dubé associated renal carcinoma. J Pathol 2007; 211:524-531. [PMID: 17323425 DOI: 10.1002/path.2139] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The Birt-Hogg-Dubé (BHD) gene is responsible for BHD syndrome, a rare autosomal dominant disease, characterized by benign hair follicle tumours, spontaneous pneumothorax and renal neoplasms with diverse histology. To elucidate its involvement in the development of renal neoplasms, we examined a total of 100 sporadic renal tumours with various histological subtypes for BHD mutation by SSCP-sequencing analyses. We found one germline insertion mutation in the C8 hotspot of exon 11 (c.1733insC), which is known to have a strong association with renal tumour occurrence. The germline-mutated patient suffered from solitary renal cell carcinoma (RCC) but did not have any other BHD manifestations or family history. The tumour revealed heterogeneous cytomorphology, mainly a mixture of eosinophilic and focally clear cells with tubulopapillary architecture. In this tumour, both BHD alleles were inactivated by germline mutation concomitant with loss of heterozygosity, and the amount of BHD mRNA detected by real-time quantitative PCR (RQ-PCR) was very low. Renal tumour subtype/nephron segment-specific gene expression detected by RQ-PCR demonstrated that the tumour expressed relatively high amounts of alpha-methylacyl-CoA racemase (AMACR) and the KIT oncogene, but relatively low amounts of carbonic anhydrase IX (CA9), aquaporin 1 (AQP1), claudin 7 (CLDN7), parvalbumin (PVALB), chloride channel Kb (CLCNKB) and 11-beta-hydroxysteroid dehydrogenase 2 (HSD11B2), suggesting diverse mRNA signatures. Further clustering analysis of 88 renal tumours based on expression of these eight genes sub-classified the tumour as close to oncocytomas and chromophobe RCCs, which are considered distal nephron-associated tumours. These data suggest that somatic mutation of BHD is relatively rare in Japanese patients. The BHD-mutated RCC identified in this study, which exhibits heterogeneous biological features in both morphology and gene expression signatures, seems to deviate from our current understanding of renal tumour classification.
Collapse
Affiliation(s)
- T Murakami
- Department of Urology and Molecular Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - F Sano
- Department of Urology and Molecular Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Y Huang
- Department of Urology and Molecular Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - A Komiya
- Department of Urology and Molecular Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - M Baba
- Department of Urology and Molecular Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Y Osada
- Department of Urology, Kanagawa Cancer Centre, Yokohama, Japan
| | - Y Nagashima
- Department of Molecular Pathology and Oncology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - K Kondo
- Department of Urology, Yokohama City University Medical Centre, Yokohama, Japan
| | - N Nakaigawa
- Department of Urology and Molecular Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - T Miura
- Department of Urology, Kanagawa Cancer Centre, Yokohama, Japan
| | - Y Kubota
- Department of Urology and Molecular Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - M Yao
- Department of Urology and Molecular Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - T Kishida
- Department of Urology, Yokohama City University Medical Centre, Yokohama, Japan
| |
Collapse
|
50
|
Chu JYS, Chung SCK, Lam AKM, Tam S, Chung SK, Chow BKC. Phenotypes developed in secretin receptor-null mice indicated a role for secretin in regulating renal water reabsorption. Mol Cell Biol 2007; 27:2499-511. [PMID: 17283064 PMCID: PMC1899889 DOI: 10.1128/mcb.01088-06] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aquaporin 2 (AQP2) is responsible for regulating the concentration of urine in the collecting tubules of the kidney under the control of vasopressin (Vp). Studies using Vp-deficient Brattleboro rats, however, indicated the existence of substantial Vp-independent mechanisms for membrane insertion, as well as transcriptional regulation, of this water channel. The Vp-independent mechanism(s) is clinically relevant to patients with X-linked nephrogenic diabetes insipidus (NDI) by therapeutically bypassing the dysfunctional Vp receptor. On the basis of studies with secretin receptor-null (SCTR(-/-)) mice, we report here for the first time that mutation of the SCTR gene could lead to mild polydipsia and polyuria. Additionally, SCTR(-/-) mice were shown to have reduced renal expression of AQP2 and AQP4, as well as altered glomerular and tubular morphology, suggesting possible disturbances in the filtration and/or water reabsorption process in these animals. By using SCTR(-/-) mice as controls and comparing them with wild-type animals, we performed both in vivo and in vitro studies that demonstrated a role for secretin in stimulating (i) AQP2 translocation from intracellular vesicles to the plasma membrane in renal medullary tubules and (ii) expression of this water channel under hyperosmotic conditions. The present study therefore provides information for at least one of the Vp-independent mechanisms that modulate the process of renal water reabsorption. Future investigations in this direction should be important in developing therapeutic means for treating NDI patients.
Collapse
Affiliation(s)
- Jessica Y S Chu
- Department of Zoology, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
| | | | | | | | | | | |
Collapse
|