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β3 Adrenergic Receptor Agonist Mirabegron Increases AQP2 and NKCC2 Urinary Excretion in OAB Patients: A Pleiotropic Effect of Interest for Patients with X-Linked Nephrogenic Diabetes Insipidus. Int J Mol Sci 2023; 24:ijms24021136. [PMID: 36674662 PMCID: PMC9865646 DOI: 10.3390/ijms24021136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/22/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
We previously reported the novel finding that β3-AR is functionally expressed in the renal tubule and shares its cellular localization with the vasopressin receptor AVPR2, whose physiological stimulation triggers antidiuresis by increasing the plasma membrane expression of the water channel AQP2 and the NKCC2 symporter in renal cells. We also showed that pharmacologic stimulation of β3-AR is capable of triggering antidiuresis and correcting polyuria, in the knockout mice for the AVPR2 receptor, the animal model of human X-linked nephrogenic diabetes insipidus (XNDI), a rare genetic disease still missing a cure. Here, to demonstrate that the same response can be evoked in humans, we evaluated the effect of treatment with the β3-AR agonist mirabegron on AQP2 and NKCC2 trafficking, by evaluating their urinary excretion in a cohort of patients with overactive bladder syndrome, for the treatment of which the drug is already approved. Compared to baseline, treatment with mirabegron significantly increased AQP2 and NKCC2 excretion for the 12 weeks of treatment. This data is a step forward in corroborating the hypothesis that in patients with XNDI, treatment with mirabegron could bypass the inactivation of AVPR2, trigger antidiuresis and correct the dramatic polyuria which is the main hallmark of this disease.
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Uchida S, Mori T, Susa K, Sohara E. NCC regulation by WNK signal cascade. Front Physiol 2023; 13:1081261. [PMID: 36685207 PMCID: PMC9845728 DOI: 10.3389/fphys.2022.1081261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 12/14/2022] [Indexed: 01/06/2023] Open
Abstract
With-no-lysine (K) (WNK) kinases have been identified as the causal genes for pseudohypoaldosteronism type II (PHAII), a rare hereditary hypertension condition characterized by hyperkalemia, hyperchloremic metabolic acidosis, and thiazide-hypersensitivity. We thought that clarifying the link between WNK and NaCl cotransporter (NCC) would bring us new mechanism(s) of NCC regulation. For the first time, we were able to produce a knock-in mouse model of PHAII and anti-phosphorylated NCC antibodies against the putative NCC phosphorylation sites and discover that constitutive activation of NCC and increased phosphorylation of NCC are the primary pathogenesis of the disease in vivo. We have since demonstrated that this regulatory mechanism is mediated by the kinases oxidative stress-response protein 1 (OSR1) and STE20/SPS1-related proline/alanine-rich kinase (SPAK) (WNK-OSR1/SPAK-NCC signaling cascade) and that the signaling is not only important in the pathological condition of PHAII but also plays a crucial physiological role in the regulation of NCC.
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Wu A, Wolley MJ, Fenton RA, Stowasser M. Using human urinary extracellular vesicles to study physiological and pathophysiological states and regulation of the sodium chloride cotransporter. Front Endocrinol (Lausanne) 2022; 13:981317. [PMID: 36105401 PMCID: PMC9465297 DOI: 10.3389/fendo.2022.981317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/09/2022] [Indexed: 11/29/2022] Open
Abstract
The thiazide-sensitive sodium chloride cotransporter (NCC), expressed in the renal distal convoluted tubule, plays a major role in Na+, Cl- and K+ homeostasis and blood pressure as exemplified by the symptoms of patients with non-functional NCC and Gitelman syndrome. NCC activity is modulated by a variety of hormones, but is also influenced by the extracellular K+ concentration. The putative "renal-K+ switch" mechanism is a relatively cohesive model that links dietary K+ intake to NCC activity, and may offer new targets for blood pressure control. However, a remaining hurdle for full acceptance of this model is the lack of human data to confirm molecular findings from animal models. Extracellular vesicles (EVs) have attracted attention from the scientific community due to their potential roles in intercellular communication, disease pathogenesis, drug delivery and as possible reservoirs of biomarkers. Urinary EVs (uEVs) are an excellent sample source for the study of physiology and pathology of renal, urothelial and prostate tissues, but the diverse origins of uEVs and their dynamic molecular composition present both methodological and data interpretation challenges. This review provides a brief overview of the state-of-the-art, challenges and knowledge gaps in current uEV-based analyses, with a focus on the application of uEVs to study the "renal-K+ switch" and NCC regulation. We also provide recommendations regarding biospecimen handling, processing and reporting requirements to improve experimental reproducibility and interoperability towards the realisation of the potential of uEV-derived biomarkers in hypertension and clinical practice.
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Affiliation(s)
- Aihua Wu
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, QLD, Australia
| | - Martin J. Wolley
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, QLD, Australia
- Department of Nephrology, Royal Brisbane and Women’s Hospital, Brisbane, QLD, Australia
| | | | - Michael Stowasser
- Endocrine Hypertension Research Centre, University of Queensland Diamantina Institute, Greenslopes and Princess Alexandra Hospitals, Brisbane, QLD, Australia
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Sung CC, Chen MH, Lin YC, Lin YC, Lin YJ, Yang SS, Lin SH. Urinary Extracellular Vesicles for Renal Tubular Transporters Expression in Patients With Gitelman Syndrome. Front Med (Lausanne) 2021; 8:679171. [PMID: 34179047 PMCID: PMC8219937 DOI: 10.3389/fmed.2021.679171] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 05/11/2021] [Indexed: 11/27/2022] Open
Abstract
Background: The utility of urinary extracellular vesicles (uEVs) to faithfully represent the changes of renal tubular protein expression remains unclear. We aimed to evaluate renal tubular sodium (Na+) or potassium (K+) associated transporters expression from uEVs and kidney tissues in patients with Gitelman syndrome (GS) caused by inactivating mutations in SLC12A3. Methods: uEVs were isolated by ultracentrifugation from 10 genetically-confirmed GS patients. Membrane transporters including Na+-hydrogen exchanger 3 (NHE3), Na+/K+/2Cl− cotransporter (NKCC2), NaCl cotransporter (NCC), phosphorylated NCC (p-NCC), epithelial Na+ channel β (ENaCβ), pendrin, renal outer medullary K1 channel (ROMK), and large-conductance, voltage-activated and Ca2+-sensitive K+ channel (Maxi-K) were examined by immunoblotting of uEVs and immunofluorescence of biopsied kidney tissues. Healthy and disease (bulimic patients) controls were also enrolled. Results: Characterization of uEVs was confirmed by nanoparticle tracking analysis, transmission electron microscopy, and immunoblotting. Compared with healthy controls, uEVs from GS patients showed NCC and p-NCC abundance were markedly attenuated but NHE3, ENaCβ, and pendrin abundance significantly increased. ROMK and Maxi-K abundance were also significantly accentuated. Immunofluorescence of the representative kidney tissues from GS patients also demonstrated the similar findings to uEVs. uEVs from bulimic patients showed an increased abundance of NCC and p-NCC as well as NHE3, NKCC2, ENaCβ, pendrin, ROMK and Maxi-K, akin to that in immunofluorescence of their kidney tissues. Conclusion: uEVs could be a non-invasive tool to diagnose and evaluate renal tubular transporter adaptation in patients with GS and may be applied to other renal tubular diseases.
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Affiliation(s)
- Chih-Chien Sung
- Division of Nephrology, Department of Medicine, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan
| | - Min-Hsiu Chen
- Division of Nephrology, Department of Medicine, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan
| | - Yi-Chang Lin
- Division of Cardiovascular Surgery, Department of Surgery, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan
| | - Yu-Chun Lin
- Deparment of Pathology, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan
| | - Yi-Jia Lin
- Deparment of Pathology, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan
| | - Sung-Sen Yang
- Division of Nephrology, Department of Medicine, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan
| | - Shih-Hua Lin
- Division of Nephrology, Department of Medicine, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan
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Rapoport RM, Soleimani M. Mechanism of Thiazide Diuretic Arterial Pressure Reduction: The Search Continues. Front Pharmacol 2019; 10:815. [PMID: 31543812 PMCID: PMC6730501 DOI: 10.3389/fphar.2019.00815] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/24/2019] [Indexed: 12/21/2022] Open
Abstract
Thiazide diuretic (TZD)-mediated chronic reduction of arterial pressure is thought to occur through decreased total peripheral vascular resistance. Further, the decreased peripheral vascular resistance is accomplished through TZD activation of an extrarenal target, resulting in inhibition of vascular constriction. However, despite greater than five decades of investigation, little progress has been made into the identification of the TZD extrarenal target. Proposed mechanisms range from direct inhibition of constrictor and activation of relaxant signaling pathways in the vascular smooth muscle to indirect inhibition through decreased neurogenic and hormonal regulatory pathways. Surprisingly, particularly in view of this lack of progress, comprehensive reviews of the subject are absent. Moreover, even though it is well recognized that 1) several types of hypertension are insensitive to TZD reduction of arterial pressure and, further, TZD fail to reduce arterial pressure in normotensive subjects and animals, and 2) different mechanisms underlie acute and chronic TZD, findings derived from these models and parameters remain largely undifferentiated. This review 1) comprehensively describes findings associated with TZD reduction of arterial pressure; 2) differentiates between observations in TZD-sensitive and TZD-insensitive hypertension, normotensive subjects/animals, and acute and chronic effects of TZD; 3) critically evaluates proposed TZD extrarenal targets; 4) proposes guiding parameters for relevant investigations into extrarenal TZD target identification; and 5) proposes a working model for TZD chronic reduction of arterial pressure through vascular dilation.
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Affiliation(s)
- Robert M Rapoport
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Manoocher Soleimani
- Research Service, Veterans Affairs Medical Center, Cincinnati, OH, United States.,Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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Urinary proteome in inherited nephrolithiasis. Urolithiasis 2018; 47:91-98. [DOI: 10.1007/s00240-018-01104-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 12/08/2018] [Indexed: 12/18/2022]
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Wardak H, Tutakhel OAZ, Van Der Wijst J. Role of the alternative splice variant of NCC in blood pressure control. Channels (Austin) 2018; 12:346-355. [PMID: 30264650 PMCID: PMC6207291 DOI: 10.1080/19336950.2018.1528820] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The renal thiazide-sensitive sodium-chloride cotransporter (NCC), located in the distal convoluted tubule (DCT) of the kidney, plays an important role in blood pressure regulation by fine-tuning sodium excretion. The human SLC12A3 gene, encoding NCC, gives rise to three isoforms, of which only the third isoform (NCC3) has been extensively investigated so far. However, recent studies unraveled the importance of the isoforms 1 and 2, collectively referred to as NCC splice variant (NCCSV), in several (patho)physiological conditions. In the human kidney, NCCSV localizes to the apical membrane of the DCT and could constitute a functional route for renal sodium-chloride reabsorption. Analysis of urinary extracellular vesicles (uEVs), a non-invasive method for measuring renal responses, demonstrated that NCCSV abundance changes in response to acute water loading and correlates with patients’ thiazide responsiveness. Furthermore, a novel phosphorylation site at serine 811 (S811), exclusively present in NCCSV, was shown to play an instrumental role in NCCSV as well as NCC3 function. This review aims to summarize these new insights of NCCSV function in humans that broadens the understanding on NCC regulation in blood pressure control.
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Affiliation(s)
- Hila Wardak
- a Department of Physiology , Radboud Institute for Molecular Life Sciences, Radboud university medical center , Nijmegen , The Netherland
| | - Omar A Z Tutakhel
- a Department of Physiology , Radboud Institute for Molecular Life Sciences, Radboud university medical center , Nijmegen , The Netherland.,b Department of Translational Metabolic Laboratory , Radboud university medical center , Nijmegen , The Netherlands
| | - Jenny Van Der Wijst
- a Department of Physiology , Radboud Institute for Molecular Life Sciences, Radboud university medical center , Nijmegen , The Netherland
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Hashimoto H, Nomura N, Shoda W, Isobe K, Kikuchi H, Yamamoto K, Fujimaru T, Ando F, Mori T, Okado T, Rai T, Uchida S, Sohara E. Metformin increases urinary sodium excretion by reducing phosphorylation of the sodium-chloride cotransporter. Metabolism 2018; 85:23-31. [PMID: 29510178 DOI: 10.1016/j.metabol.2018.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/15/2018] [Accepted: 02/23/2018] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Metformin is an antidiabetic drug that is widely used to treat patients with diabetes mellitus. Recent studies have reported that treatment with metformin not only improved blood glucose levels but also reduced blood pressure. However, it remains unclear how metformin reduces blood pressure. We hypothesized that metformin affects sodium reabsorption in the kidneys. METHODS Urinary sodium excretion and expression of renal sodium transporters were examined in 8-week-old male C57BL/6 mice with acute and chronic treatment of metformin. In addition, we examined metformin effects using ex vivo preparations of mice kidney slices. RESULTS In this study, we demonstrated that metformin increased urinary sodium excretion by reducing phosphorylation of the thiazide-sensitive Na-Cl cotransporter (NCC) in acute and chronic metformin administration. We also confirmed reduction of phosphorylated NCC in an ex vivo study. The activity of other renal sodium transporters, such as NKCC2, ENaC, and NHE3 did not show significant changes. WNK-OSR1/SPAK kinase signals were not involved in this inactivation effect of metformin on NCC. CONCLUSION Metformin increased urinary sodium excretion by reducing phosphorylation of NCC, suggesting its role in improving hypertension.
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Affiliation(s)
- Hiroko Hashimoto
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Naohiro Nomura
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Wakana Shoda
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Kiyoshi Isobe
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Hiroaki Kikuchi
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Kouhei Yamamoto
- Department of Comprehensive Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Takuya Fujimaru
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Fumiaki Ando
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Takayasu Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Tomokazu Okado
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Tatemitsu Rai
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan
| | - Eisei Sohara
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8519, Japan.
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Yoshida S, Araki Y, Mori T, Sasaki E, Kasagi Y, Isobe K, Susa K, Inoue Y, Bomont P, Okado T, Rai T, Uchida S, Sohara E. Decreased KLHL3 expression is involved in the pathogenesis of pseudohypoaldosteronism type II caused by cullin 3 mutation in vivo. Clin Exp Nephrol 2018; 22:1251-1257. [PMID: 29869755 DOI: 10.1007/s10157-018-1593-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 05/25/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND Pseudohypoaldosteronism type II (PHAII) is a hereditary hypertensive disease caused by mutations in four genes: WNK1, WNK4, Kelch-like3 (KLHL3), and cullin3 (CUL3). Recently, it was revealed that CUL3-KLHL3 E3 ligase complex ubiquitinates WNK1 and WNK4, leading to their degradation, and that a common pathogenesis of PHAII is defective WNK degradation due to CUL3-KLHL3 E3 ligase complex impairment. PHAII-causing CUL3 mutations mediate exon9 skipping, producing a CUL3 protein with a 57-amino acid deletion (Δ403-459). However, the pathogenic effects of KLHL3, an adaptor protein that links WNKs with CUL3, in PHAII caused by CUL3 mutation remain unclear. METHODS To clarify detailed pathophysiological mechanisms underlying PHAII caused by CUL3 mutation in vivo, we generated and analyzed knock-in mice carrying the same CUL3 exon9 deletion (CUL3WT/Δex9) as that reported in PHAII patients. RESULTS CUL3WT/Δex9 mice exhibited a PHAII-like phenotype. Interestingly, we confirmed markedly decreased KLHL3 expression in CUL3WT/Δex9 mice by confirming the true KLHL3 band in vivo. However, the expression of other KLHL family proteins, such as KLHL2, was comparable between WT and mutant mice. CONCLUSION KLHL3 expression was decreased in CUL3WT/Δex9 mice. However, expression levels of other KLHL family proteins were comparable between the wild-type and mutant mice. These findings indicate that the decreased abundance of KLHL3 is a specific phenomenon caused by mutant CUL3 (Δexon9). Our findings would improve our understanding of the pathogenesis of PHAII caused by CUL3 mutation in vivo.
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Affiliation(s)
- Sayaka Yoshida
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Yuya Araki
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Takayasu Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Emi Sasaki
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Yuri Kasagi
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Kiyoshi Isobe
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Koichiro Susa
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Yuichi Inoue
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Pascale Bomont
- Avenir-Atip Team, INM, INSERM, University of Montpellier, 34091, Montpellier Cedex 5, France
| | - Tomokazu Okado
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Tatemitsu Rai
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Eisei Sohara
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan.
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AQP2 in human urine is predominantly localized to exosomes with preserved water channel activities. Clin Exp Nephrol 2018; 22:782-788. [DOI: 10.1007/s10157-018-1538-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 01/21/2018] [Indexed: 12/23/2022]
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Tutakhel OAZ, Moes AD, Valdez-Flores MA, Kortenoeven MLA, Vrie MVD, Jeleń S, Fenton RA, Zietse R, Hoenderop JGJ, Hoorn EJ, Hilbrands L, Bindels RJM. NaCl cotransporter abundance in urinary vesicles is increased by calcineurin inhibitors and predicts thiazide sensitivity. PLoS One 2017; 12:e0176220. [PMID: 28430812 PMCID: PMC5400280 DOI: 10.1371/journal.pone.0176220] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 04/08/2017] [Indexed: 11/30/2022] Open
Abstract
Animal studies have shown that the calcineurin inhibitors (CNIs) cyclosporine and tacrolimus can activate the thiazide-sensitive NaCl cotransporter (NCC). A common side effect of CNIs is hypertension. Renal salt transporters such as NCC are excreted in urinary extracellular vesicles (uEVs) after internalization into multivesicular bodies. Human studies indicate that CNIs also increase NCC abundance in uEVs, but results are conflicting and no relationship with NCC function has been shown. Therefore, we investigated the effects of CsA and Tac on the abundance of both total NCC (tNCC) and phosphorylated NCC at Thr60 phosphorylation site (pNCC) in uEVs, and assessed whether NCC abundance in uEVs predicts the blood pressure response to thiazide diuretics. Our results show that in kidney transplant recipients treated with cyclosporine (n = 9) or tacrolimus (n = 23), the abundance of both tNCC and pNCC in uEVs is 4–5 fold higher than in CNI-free kidney transplant recipients (n = 13) or healthy volunteers (n = 6). In hypertensive kidney transplant recipients, higher abundances of tNCC and pNCC prior to treatment with thiazides predicted the blood pressure response to thiazides. During thiazide treatment, the abundance of pNCC in uEVs increased in responders (n = 10), but markedly decreased in non-responders (n = 8). Thus, our results show that CNIs increase the abundance of both tNCC and pNCC in uEVs, and these increases correlate with the blood pressure response to thiazides. This implies that assessment of NCC in uEVs could represent an alternate method to guide anti-hypertensive therapy in kidney transplant recipients.
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Affiliation(s)
- Omar A. Z. Tutakhel
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Arthur D. Moes
- Department of Internal Medicine, Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Marco A. Valdez-Flores
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
- Programa Regional en Doctorado en Biotecnología, Universidad Autónoma de Sinaloa, Sinaloa, Mexico
| | - Marleen L. A. Kortenoeven
- Department of Biomedicine, Center for Interaction of Proteins in Epithelial Transport, Aarhus University, Aarhus, Denmark
| | - Mathijs v. D. Vrie
- Department of Nephrology, Radboud university medical center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Sabina Jeleń
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Robert A. Fenton
- Department of Biomedicine, Center for Interaction of Proteins in Epithelial Transport, Aarhus University, Aarhus, Denmark
| | - Robert Zietse
- Department of Internal Medicine, Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Joost G. J. Hoenderop
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Ewout J. Hoorn
- Department of Internal Medicine, Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Luuk Hilbrands
- Department of Nephrology, Radboud university medical center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - René J. M. Bindels
- Department of Physiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
- * E-mail:
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Sasaki E, Susa K, Mori T, Isobe K, Araki Y, Inoue Y, Yoshizaki Y, Ando F, Mori Y, Mandai S, Zeniya M, Takahashi D, Nomura N, Rai T, Uchida S, Sohara E. KLHL3 Knockout Mice Reveal the Physiological Role of KLHL3 and the Pathophysiology of Pseudohypoaldosteronism Type II Caused by Mutant KLHL3. Mol Cell Biol 2017; 37:e00508-16. [PMID: 28052936 PMCID: PMC5359427 DOI: 10.1128/mcb.00508-16] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 10/17/2016] [Accepted: 12/29/2016] [Indexed: 01/06/2023] Open
Abstract
Mutations in the with-no-lysine kinase 1 (WNK1), WNK4, kelch-like 3 (KLHL3), and cullin3 (CUL3) genes are known to cause the hereditary disease pseudohypoaldosteronism type II (PHAII). It was recently demonstrated that this results from the defective degradation of WNK1 and WNK4 by the KLHL3/CUL3 ubiquitin ligase complex. However, the other physiological in vivo roles of KLHL3 remain unclear. Therefore, here we generated KLHL3-/- mice that expressed β-galactosidase (β-Gal) under the control of the endogenous KLHL3 promoter. Immunoblots of β-Gal and LacZ staining revealed that KLHL3 was expressed in some organs, such as brain. However, the expression levels of WNK kinases were not increased in any of these organs other than the kidney, where WNK1 and WNK4 increased in KLHL3-/- mice but not in KLHL3+/- mice. KLHL3-/- mice also showed PHAII-like phenotypes, whereas KLHL3+/- mice did not. This clearly demonstrates that the heterozygous deletion of KLHL3 was not sufficient to cause PHAII, indicating that autosomal dominant type PHAII is caused by the dominant negative effect of mutant KLHL3. We further demonstrated that the dimerization of KLHL3 can explain this dominant negative effect. These findings could help us to further understand the physiological roles of KLHL3 and the pathophysiology of PHAII caused by mutant KLHL3.
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Affiliation(s)
- Emi Sasaki
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Koichiro Susa
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takayasu Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kiyoshi Isobe
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yuya Araki
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yuichi Inoue
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yuki Yoshizaki
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Fumiaki Ando
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yutaro Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shintaro Mandai
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Moko Zeniya
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Daiei Takahashi
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Naohiro Nomura
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Tatemitsu Rai
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Eisei Sohara
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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Street J, Koritzinsky E, Glispie D, Star R, Yuen P. Urine Exosomes: An Emerging Trove of Biomarkers. Adv Clin Chem 2017; 78:103-122. [PMID: 28057185 DOI: 10.1016/bs.acc.2016.07.003] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Exosomes are released by most cells and can be isolated from all biofluids including urine. Exosomes are small vesicles formed as part of the endosomal pathway that contain cellular material surrounded by a lipid bilayer that can be traced to the plasma membrane. Exosomes are potentially a more targeted source of material for biomarker discovery than unfractionated urine, and provide diagnostic and pathophysiological information without an invasive tissue biopsy. Cytoplasmic contents including protein, mRNA, miRNA, and lipids have all been studied within the exosomal fraction. Many prospective urinary exosomal biomarkers have been successfully identified for a variety of kidney or genitourinary tract conditions; detection of systemic conditions may also be possible. Isolation and analysis of exosomes can be achieved by several approaches, although many require specialized equipment or involve lengthy protocols. The need for timely analysis in the clinical setting has driven considerable innovation with several promising options recently emerging. Consensus on exosome isolation, characterization, and normalization procedures would resolve critical clinical translational bottlenecks for existing candidate exosomal biomarkers and provide a template for additional discovery studies.
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Koumangoye R, Delpire E. The Ste20 kinases SPAK and OSR1 travel between cells through exosomes. Am J Physiol Cell Physiol 2016; 311:C43-53. [PMID: 27122160 DOI: 10.1152/ajpcell.00080.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 04/25/2016] [Indexed: 12/23/2022]
Abstract
Proteomics studies have identified Ste20-related proline/alanine-rich kinase (SPAK) and oxidative stress response 1 (OSR1) in exosomes isolated from body fluids such as blood, saliva, and urine. Because proteomics studies likely overestimate the number of exosome proteins, we sought to confirm and extend this observation using traditional biochemical and cell biology methods. We utilized HEK293 cells in culture to verify the packaging of these Ste20 kinases in exosomes. Using a series of centrifugation and filtration steps of conditioned culture medium isolated from HEK293 cells, we isolated nanovesicles in the range of 40-100 nm. We show that these small vesicles express the tetraspanin protein CD63 and lack endoplasmic reticulum and Golgi markers, consistent with these being exosomes. We show by Western blot and immunogold analyses that these exosomes express SPAK, OSR1, and Na-K-Cl cotransporter 1 (NKCC1). We show that exosomes are not only secreted by cells, but also accumulated by adjacent cells. Indeed, exposing cultured cells to exosomes produced by other cells expressing a fluorescently labeled kinase resulted in the kinase finding its way into the cytoplasm of these cells, consistent with the idea of exosomes serving as cell-to-cell communication vessels. Similarly, coculturing cells expressing different fluorescently tagged proteins resulted in the exchange of proteins between cells. In addition, we show that both SPAK and OSR1 kinases entering cells through exosomes are preferentially expressed at the plasma membrane and that the kinases in exosomes are functional and maintain NKCC1 in a phosphorylated state.
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Affiliation(s)
- Rainelli Koumangoye
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee
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15
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Salih M, Fenton RA, Knipscheer J, Janssen JW, Vredenbregt-van den Berg MS, Jenster G, Zietse R, Hoorn EJ. An immunoassay for urinary extracellular vesicles. Am J Physiol Renal Physiol 2016; 310:F796-F801. [DOI: 10.1152/ajprenal.00463.2015] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/25/2016] [Indexed: 11/22/2022] Open
Abstract
Although nanosized urinary extracellular vesicles (uEVs) are increasingly used for biomarker discovery, their isolation currently relies on time-consuming techniques hindering high-throughput application. To navigate this problem, we designed an immunoassay to isolate, quantify, and normalize uEV proteins. The uEV immunoassay consists of a biotinylated CD9 antibody to isolate uEVs, an antibody against the protein of interest, and two conjugated antibodies to quantify the protein of interest and CD9. As a proof of principle, the immunoassay was developed to analyze the water channel aquaporin-2 (AQP2) and the sodium-chloride cotransporter (NCC). CD9 was used as a capture antibody because immunoprecipitation showed that anti-CD9 antibody, but not anti-CD63 antibody, isolated AQP2 and NCC. CD9 correlated strongly with urine creatinine, allowing CD9 to be used for normalization of spot urines. The uEV immunoassay detected AQP2 and NCC with high sensitivity, low coefficients of variance, and stability in dilution series. After water loading in healthy subjects, the uEV immunoassay detected decreases in AQP2 and NCC equally well as the traditional method using ultracentrifugation and immunoblot. The uEV immunoassay also reliably detected lower and higher AQP2 or NCC levels in uEVs from patients with pathological water or salt reabsorption, respectively. In summary, we report a novel approach to analyze uEVs that circumvents existing isolation and normalization issues, requires small volumes of urine, and detects anticipated changes in physiological responses and clinical disorders.
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Affiliation(s)
- Mahdi Salih
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Jeroen Knipscheer
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Joost W. Janssen
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Guido Jenster
- Department of Urology, Erasmus Medical Center, Rotterdam, The Netherlands; and
| | - Robert Zietse
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ewout J. Hoorn
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
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16
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Ferdaus MZ, McCormick JA. The CUL3/KLHL3-WNK-SPAK/OSR1 pathway as a target for antihypertensive therapy. Am J Physiol Renal Physiol 2016; 310:F1389-96. [PMID: 27076645 DOI: 10.1152/ajprenal.00132.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/07/2016] [Indexed: 01/11/2023] Open
Abstract
Chronic high blood pressure (hypertension) is the most common disease in the Unites States. While several classes of drugs exist to treat it, many patients (up to 10 million Americans) respond poorly to therapy, even when multiple classes are used. Recent evidence suggests that a significant portion of patients will always remain hypertensive despite maximum therapy with the drugs currently available. Therefore, there is a pressing need to develop novel antihypertensive agents. One limitation has been the identification of new targets, a limitation that has been overcome by recent insights into the mechanisms underlying monogenic forms of hypertension. The disease familial hyperkalemic hypertension is caused by mutations in with-no-lysine (WNK) kinases 1 and 4 and in cullin-3 and kelch-like 3, components of an E3 ubiquitin ligase complex that promotes WNK kinase degradation. The study of the mechanisms by which this pathway regulates blood pressure has identified several candidates for the development of new antihypertensive agents. This pathway is particularly attractive since its inhibition may not only reduce renal sodium reabsorption along multiple segments but may also reduce vascular tone. Here, we will describe the mechanisms by which this pathway regulate blood pressure and discuss the potential of targeting it to develop new antihypertensive drugs.
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Affiliation(s)
- Mohammed Z Ferdaus
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - James A McCormick
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
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17
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Abdeen A, Sonoda H, Oshikawa S, Hoshino Y, Kondo H, Ikeda M. Acetazolamide enhances the release of urinary exosomal aquaporin-1. Nephrol Dial Transplant 2016; 31:1623-32. [PMID: 27190370 DOI: 10.1093/ndt/gfw033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 01/12/2016] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Renal aquaporin-1 (AQP1), a water channel protein, is known to be secreted into urine, conveyed by nano-sized extracellular vesicles called exosomes. A previous study has demonstrated that acetazolamide (AZ), a diuretic that inhibits carbonic anhydrases, alters the expression level of AQP1 in cultured cells. Here we investigated whether AZ alters the release of urinary exosomal AQP1 in vivo. METHODS The effect of AZ on urinary exosomal AQP1 secretion was examined in rats and compared with furosemide (another diuretic), NaHCO3 (an alkalizing agent) and NH4Cl (an acidifying agent). Urine, blood and kidney samples were obtained 2 h after each treatment. Urinary exosomes were isolated by a differential centrifugation technique and urinary exosomal proteins were analyzed by immunoblotting. RESULTS The release of exosomal AQP1 into urine was markedly increased after treatment with AZ, accompanied by alkaluria and metabolic acidosis. Immunohistochemistry clearly demonstrated that AZ increased the apical membrane expression of AQP1 in the proximal tubules. AZ did not affect the release of exosomal marker proteins (tumor susceptibility gene 101 protein and apoptosis-linked gene 2 interacting protein X). Treatment with furosemide did not change, whereas NaHCO3 and NH4Cl decreased the exosomal release of AQP1. CONCLUSION The present findings indicate that AZ increases the release of exosomal AQP1 into urine in association with enhanced apical membrane expression of AQP1.
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Affiliation(s)
- Ahmed Abdeen
- Department of Veterinary Pharmacology, University of Miyazaki, Miyazaki 889-2192, Japan Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Benha University, Toukh 13736, Egypt
| | - Hiroko Sonoda
- Department of Veterinary Pharmacology, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Sayaka Oshikawa
- Department of Veterinary Pharmacology, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Yuya Hoshino
- Department of Veterinary Pharmacology, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Hiroaki Kondo
- Department of Veterinary Pharmacology, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Masahiro Ikeda
- Department of Veterinary Pharmacology, University of Miyazaki, Miyazaki 889-2192, Japan
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18
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Urinary extracellular vesicles as markers to assess kidney sodium transport. Curr Opin Nephrol Hypertens 2016; 25:67-72. [DOI: 10.1097/mnh.0000000000000192] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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19
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Tutakhel OAZ, Jeleń S, Valdez-Flores M, Dimke H, Piersma SR, Jimenez CR, Deinum J, Lenders JW, Hoenderop JGJ, Bindels RJM. Alternative splice variant of the thiazide-sensitive NaCl cotransporter: a novel player in renal salt handling. Am J Physiol Renal Physiol 2016; 310:F204-16. [DOI: 10.1152/ajprenal.00429.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 10/31/2015] [Indexed: 11/22/2022] Open
Abstract
The thiazide-sensitive NaCl cotransporter (NCC) is an important pharmacological target in the treatment of hypertension. The human SLC12A3 gene, encoding NCC, gives rise to three isoforms. Only the third isoform has been extensively investigated. The aim of the present study was, therefore, to establish the abundance and localization of the almost identical isoforms 1 and 2 (NCC1/2) in the human kidney and to determine their functional properties and regulation in physiological conditions. Immunohistochemical analysis of NCC1/2 in the human kidney revealed that NCC1/2 localizes to the apical plasma membrane of the distal convoluted tubule. Importantly, NCC1/2 mRNA constitutes ∼44% of all NCC isoforms in the human kidney. Functional analysis performed in the Xenopus laevis oocyte revealed that thiazide-sensitive 22Na+ transport of NCC1 was significantly increased compared with NCC3. Mimicking a constitutively active phosphorylation site at residue 811 (S811D) in NCC1 further augmented Na+ transport, while a nonphosphorylatable variant (S811A) of NCC1 prevented this enhanced response. Analysis of human urinary exosomes demonstrated that water loading in human subjects significantly reduces the abundance of NCC1/2 in urinary exosomes. The present study highlights that previously underrepresented NCC1/2 is a fully functional thiazide-sensitive NaCl-transporting protein. Being significantly expressed in the kidney, it may constitute a unique route of renal NaCl reabsorption and could, therefore, play an important role in blood pressure regulation.
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Affiliation(s)
- Omar A. Z. Tutakhel
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Sabina Jeleń
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marco Valdez-Flores
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Sander R. Piersma
- OncoProteomics Laboratory, Department of Medical Oncology, VU University Medical Center, Amsterdam, The Netherlands
| | - Connie R. Jimenez
- OncoProteomics Laboratory, Department of Medical Oncology, VU University Medical Center, Amsterdam, The Netherlands
| | - Jaap Deinum
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jacques W. Lenders
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Medicine III, University Hospital Carl Gustav Carus, Technische Universität, Dresden, Germany; and
| | - Joost G. J. Hoenderop
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - René J. M. Bindels
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
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Araki Y, Rai T, Sohara E, Mori T, Inoue Y, Isobe K, Kikuchi E, Ohta A, Sasaki S, Uchida S. Generation and analysis of knock-in mice carrying pseudohypoaldosteronism type II-causing mutations in the cullin 3 gene. Biol Open 2015; 4:1509-17. [PMID: 26490675 PMCID: PMC4728349 DOI: 10.1242/bio.013276] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Pseudohypoaldosteronism type II (PHAII) is a hereditary hypertensive disease caused by mutations in four different genes: with-no-lysine kinases (WNK) 1 and 4, Kelch-like family member 3 (KLHL3), and cullin 3 (Cul3). Cul3 and KLHL3 form an E3 ligase complex that ubiquitinates and reduces the expression level of WNK4. PHAII-causing mutations in WNK4 and KLHL3 impair WNK4 ubiquitination. However, the molecular pathogenesis of PHAII caused by Cul3 mutations is unclear. In cultured cells and human leukocytes, PHAII-causing Cul3 mutations result in the skipping of exon 9, producing mutant Cul3 protein lacking 57 amino acids. However, whether this phenomenon occurs in the kidneys and is responsible for the pathogenesis of PHAII in vivo is unknown. We generated knock-in mice carrying a mutation in the C-terminus of intron 8 of Cul3, c.1207−1G>A, which corresponds to a PHAII-causing mutation in the human Cul3 gene. Heterozygous Cul3G(−1)A/+ knock-in mice did not exhibit PHAII phenotypes, and the skipping of exon 9 was not evident in their kidneys. However, the level of Cul3 mRNA expression in the kidneys of heterozygous knock-in mice was approximately half that of wild-type mice. Furthermore, homozygous knock-in mice were nonviable. It suggested that the mutant allele behaved like a knockout allele and did not produce Cul3 mRNA lacking exon 9. A reduction in Cul3 expression alone was not sufficient to develop PHAII in the knock-in mice. Our findings highlighted the pathogenic role of mutant Cul3 protein and provided insight to explain why PHAII-causing mutations in Cul3 cause kidney-predominant PHAII phenotypes. Summary: A knock-in mutation in intron 8 of Cul3 in mice led to decreased Cul3 protein expression. Decreased Cul3 protein expression alone did not cause pseudohypoaldosteronism type II (PHAII).
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Affiliation(s)
- Yuya Araki
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-0034, Japan
| | - Tatemitsu Rai
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-0034, Japan
| | - Eisei Sohara
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-0034, Japan
| | - Takayasu Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-0034, Japan
| | - Yuichi Inoue
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-0034, Japan
| | - Kiyoshi Isobe
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-0034, Japan
| | - Eriko Kikuchi
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-0034, Japan
| | - Akihito Ohta
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-0034, Japan
| | - Sei Sasaki
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-0034, Japan
| | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-0034, Japan
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Sasaki S, Saijo Y, Ohmoto Y, Iwata F, Koga D, Katsuragi K. Alkali treatment stabilizes fluctuations of urine AQP2 values measured by ELISA. Clin Exp Nephrol 2015; 20:450-5. [PMID: 26463736 PMCID: PMC4891367 DOI: 10.1007/s10157-015-1176-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 09/28/2015] [Indexed: 11/26/2022]
Abstract
Background Aquaporin-2 (AQP2) in urine is now measured in many water-balance disorders and regarded as a useful biomarker for diagnosis and prognosis. An enzyme-linked immunosorbent assay (ELISA) method has been developed for measurement of large numbers of clinical samples. However, fluctuations in the measured values were sometimes observed depending on storage conditions. Urine AQP2 is present in exosome membranes and we speculated that this structural organization causes the fluctuations. Methods Human urine samples from healthy subjects were measured by ELISA. Effects of maneuvers to disrupt the exosome membrane mechanically (freezing and thawing at different temperatures) and chemically (treating with alkali and detergents) prior to ELISA were examined. Results Urine samples stored at 4 or −80 °C did not show significant AQP2 values, whereas those stored at −25 °C for more that 2 weeks provided the values. Urine samples treated with 0.4 N NaOH and 0.5 % Triton X-305 showed the consistent and comparable values to those stored at −25 °C. Conclusion Pretreatment with alkali (0.4 N NaOH) to disrupt exosome membranes allowed consistent ELISA measurements of urinary AQP2. This simple method is applicable to ELISA of other membrane proteins included in exosomes.
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Affiliation(s)
- Sei Sasaki
- Department of Nephrology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, 113-8519, Tokyo, Japan.
| | - Yoko Saijo
- Diagnostic Division, Department of Research and Development, Otsuka Pharmaceutical Co., Ltd, Tokyo, Japan
| | - Yasukazu Ohmoto
- Institute of Biomedical Innovation, Otsuka Pharmaceutical Co., Ltd, Tokyo, Japan
| | - Fusako Iwata
- Institute of Biomedical Innovation, Otsuka Pharmaceutical Co., Ltd, Tokyo, Japan
| | - Daisuke Koga
- Diagnostic Division, Department of Research and Development, Otsuka Pharmaceutical Co., Ltd, Tokyo, Japan
| | - Kiyonori Katsuragi
- Diagnostic Division, Department of Research and Development, Otsuka Pharmaceutical Co., Ltd, Tokyo, Japan
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Erdbrügger U, Le TH. Extracellular Vesicles in Renal Diseases: More than Novel Biomarkers? J Am Soc Nephrol 2015; 27:12-26. [PMID: 26251351 DOI: 10.1681/asn.2015010074] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Extracellular vesicles from the urine and circulation have gained significant interest as potential diagnostic biomarkers in renal diseases. Urinary extracellular vesicles contain proteins from all sections of the nephron, whereas most studied circulating extracellular vesicles are derived from platelets, immune cells, and the endothelium. In addition to their diagnostic role as markers of kidney and vascular damage, extracellular vesicles may have functional significance in renal health and disease by facilitating communication between cells and protecting against kidney injury and bacterial infection in the urinary tract. However, the current understanding of extracellular vesicles has derived mostly from studies with very small numbers of patients or in vitro data. Moreover, accurate assessment of these vesicles remains a challenge, in part because of a lack of consensus in the methodologies to measure extracellular vesicles and the inability of most techniques to capture the entire size range of these vesicles. However, newer techniques and standardized protocols to improve the detection of extracellular vesicles are in development. A clearer understanding of the composition and biology of extracellular vesicles will provide insights into their pathophysiologic, diagnostic, and therapeutic roles.
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Affiliation(s)
- Uta Erdbrügger
- Department of Medicine, Division of Nephrology, University of Virginia Health System, Charlottesville, Virginia
| | - Thu H Le
- Department of Medicine, Division of Nephrology, University of Virginia Health System, Charlottesville, Virginia
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23
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Exosomes in urine biomarker discovery. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 845:43-58. [PMID: 25355568 DOI: 10.1007/978-94-017-9523-4_5] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Nanovesicles present in urine the so-called urinary exosomes have been found to be secreted by every epithelial cell type lining the urinary tract system in human. Urinary exosomes are an appealing source for biomarker discovery as they contain molecular constituents of their cell of origin, including proteins and genetic materials, and they can be isolated in a non-invasive manner. Following the discovery of urinary exosomes in 2004, many studies have been performed using urinary exosomes as a starting material to identify biomarkers in various renal, urogenital, and systemic diseases. Here, we describe the discovery of urinary exosomes and address the issues on the collection, isolation, and normalization of urinary exosomes as well as delineate the systems biology approach to biomarker discovery using urinary exosomes.
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24
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Abdeen A, Sonoda H, El-Shawarby R, Takahashi S, Ikeda M. Urinary excretion pattern of exosomal aquaporin-2 in rats that received gentamicin. Am J Physiol Renal Physiol 2014; 307:F1227-37. [DOI: 10.1152/ajprenal.00140.2014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Urinary exosomes are nano-sized vesicles secreted into urine from all types of renal epithelial cells and are known to contain possible biomarker proteins for renal diseases. Gentamicin has been reported to decrease the level of renal aquaporin (AQP)2, which is known to be mainly expressed in renal collecting ducts and excreted into the urine via exosomes. In the present study, we investigated whether urinary exosomal AQP2 could serve as a potential biomarker for gentamicin-induced nephrotoxicity, especially collecting duct cell dysfunction. Gentamicin was given to rats intraperitoneally once every day starting on day 0. Gentamicin significantly increased the plasma creatinine concentration from day 5 and beyond. Also, gentamicin induced polyuria and a defective urine concentration mechanism on day 7, suggesting gentamicin-induced collecting duct cell dysfunction. Immunoblot analysis showed that gentamicin significantly increased urinary exosomal AQP2 excretion on day 1 but decreased it on day 7 compared with the control group. Similarly, increased excretion of exosomal tumor susceptibility gene 101 protein, frequently used as an exosome marker protein, was observed on day 1. However, gentamicin did not significantly affect the urinary excretion of exosomal tumor susceptibility gene 101 on day 7. Gentamicin slightly decreased renal AQP2 expression on day 2 and markedly decreased it on day 8. These data strongly suggest that the use of urinary exosomal AQP2 as a biomarker may allow detection of gentamicin-induced collecting duct cell dysfunction. Furthermore, urinary exosomal AQP2 might also be useful for the early detection of gentamicin-induced renal injury in addition to collecting duct injury.
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Affiliation(s)
- Ahmed Abdeen
- Department of Veterinary Pharmacology, University of Miyazaki, Miyazaki, Japan; and
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Benha University, Toukh, Egypt
| | - Hiroko Sonoda
- Department of Veterinary Pharmacology, University of Miyazaki, Miyazaki, Japan; and
| | - Ragab El-Shawarby
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Benha University, Toukh, Egypt
| | - Saki Takahashi
- Department of Veterinary Pharmacology, University of Miyazaki, Miyazaki, Japan; and
| | - Masahiro Ikeda
- Department of Veterinary Pharmacology, University of Miyazaki, Miyazaki, Japan; and
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Corbetta S, Raimondo F, Tedeschi S, Syrèn ML, Rebora P, Savoia A, Baldi L, Bettinelli A, Pitto M. Urinary exosomes in the diagnosis of Gitelman and Bartter syndromes. Nephrol Dial Transplant 2014; 30:621-30. [DOI: 10.1093/ndt/gfu362] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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McCormick JA, Yang CL, Zhang C, Davidge B, Blankenstein KI, Terker AS, Yarbrough B, Meermeier NP, Park HJ, McCully B, West M, Borschewski A, Himmerkus N, Bleich M, Bachmann S, Mutig K, Argaiz ER, Gamba G, Singer JD, Ellison DH. Hyperkalemic hypertension-associated cullin 3 promotes WNK signaling by degrading KLHL3. J Clin Invest 2014; 124:4723-36. [PMID: 25250572 DOI: 10.1172/jci76126] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 08/13/2014] [Indexed: 01/07/2023] Open
Abstract
Familial hyperkalemic hypertension (FHHt) is a monogenic disease resulting from mutations in genes encoding WNK kinases, the ubiquitin scaffold protein cullin 3 (CUL3), or the substrate adaptor kelch-like 3 (KLHL3). Disease-associated CUL3 mutations abrogate WNK kinase degradation in cells, but it is not clear how mutant forms of CUL3 promote WNK stability. Here, we demonstrated that an FHHt-causing CUL3 mutant (CUL3 Δ403-459) not only retains the ability to bind and ubiquitylate WNK kinases and KLHL3 in cells, but is also more heavily neddylated and activated than WT CUL3. In cells, activated CUL3 Δ403-459 depleted KLHL3, preventing WNK degradation, despite increased CUL3-mediated WNK ubiquitylation; therefore, CUL3 loss in kidney should phenocopy FHHt in murine models. As predicted, nephron-specific deletion of Cul3 in mice did increase WNK kinase levels and the abundance of phosphorylated Na-Cl cotransporter (NCC). Over time, however, Cul3 deletion caused renal dysfunction, including hypochloremic alkalosis, diabetes insipidus, and salt-sensitive hypotension, with depletion of sodium potassium chloride cotransporter 2 and aquaporin 2. Moreover, these animals exhibited renal inflammation, fibrosis, and increased cyclin E. These results indicate that FHHt-associated CUL3 Δ403-459 targets KLHL3 for degradation, thereby preventing WNK degradation, whereas general loss of CUL3 activity - while also impairing WNK degradation - has widespread toxic effects in the kidney.
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Sasaki S. [111th Scientific Meeting of the Japanese Society of Internal Medicine: Invited Lecture: 4. Homeostatic regulation of body fluid by kidney and its disturbances]. NIHON NAIKA GAKKAI ZASSHI. THE JOURNAL OF THE JAPANESE SOCIETY OF INTERNAL MEDICINE 2014; 103:2074-2083. [PMID: 27522755 DOI: 10.2169/naika.103.2074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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Jensen JM, Mose FH, Kulik AEO, Bech JN, Fenton RA, Pedersen EB. Abnormal urinary excretion of NKCC2 and AQP2 in response to hypertonic saline in chronic kidney disease: an intervention study in patients with chronic kidney disease and healthy controls. BMC Nephrol 2014; 15:101. [PMID: 24970686 PMCID: PMC4094915 DOI: 10.1186/1471-2369-15-101] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 06/11/2014] [Indexed: 12/05/2022] Open
Abstract
Background Renal handling of sodium and water is abnormal in chronic kidney disease (CKD). The aim of this study was to test the hypothesis that abnormal activity of the aquaporin-2 water channels (AQP2), the sodium-potassium-2chloride transporter (NKCC2) and/or the epithelial sodium channels (ENaC) contribute to this phenomenon. Methods 23 patients with CKD and 24 healthy controls at baseline and after 3% saline infusion were compared. The following measurements were performed: urinary concentrations of AQP2 (u-AQP2), NKCC2 (u-NKCC2), ENaC (u-ENaCγ), glomerular filtration rate (GFR) estimated by 51Cr-EDTA clearance, free water clearance (CH2O), urinary output (UO), fractional excretion of sodium (FENa), plasma concentrations of AVP, renin (PRC), Angiotensin II (ANG II), Aldosterone (Aldo) and body fluid volumes. Results At baseline, GFR was 34 ml/min in CKD patients and 89 ml/ml in controls. There were no significant differences in u-AQP2, u-NKCC2 or u-ENaCγ, but FENa, p-Aldo and p-AVP were higher in CKD patients than controls. In response to hypertonic saline, patients with CKD had an attenuated decrease in CH2O and UO. A greater increase in U-AQP2 was observed in CKD patients compared to controls. Furthermore, u-NKCC2 increased in CKD patients, whereas u-NKCC2 decreased in controls. Body fluid volumes did not significantly differ. Conclusions In response to hypertonic saline, u-NKCC2 increased, suggesting an increased sodium reabsorption via NKCC2 in patients with CKD. U-AQP2 increased more in CKD patients, despite an attenuated decrease in CH2O. Thus, though high levels of p-AVP and p-Aldo, the kidneys can only partly compensate and counteract acute volume expansion due to a defective tubular response. Trial registration Clinical trial no: NCT01623661. Date of trial registration: 18.06.2012.
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Affiliation(s)
- Janni M Jensen
- Department of Medical Research, Holstebro Hospital, University Clinic in Nephrology and Hypertension, Laegaardvej 12, 7500 Holstebro, Denmark.
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Salih M, Zietse R, Hoorn EJ. Urinary extracellular vesicles and the kidney: biomarkers and beyond. Am J Physiol Renal Physiol 2014; 306:F1251-9. [DOI: 10.1152/ajprenal.00128.2014] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Extracellular vesicles have been isolated in various body fluids, including urine. The cargo of urinary extracellular vesicles (uEVs) is composed of proteins and nucleic acids reflecting the physiological and possibly pathophysiological state of cells lining the nephron. Because urine is a noninvasive and readily available biofluid, the discovery of uEVs has opened a new field of biomarker research. Their potential use as diagnostic, prognostic, or therapeutic biomarkers for various kidney diseases, including glomerulonephritis, acute kidney injury, tubular disorders, and polycystic kidney disease, is currently being explored. Some challenges, however, remain. These challenges include the need to standardize isolation methods, normalization between samples, and validation of candidate biomarkers. Also, the development of a high-throughput platform to isolate and analyze uEVs, for example, an enzyme-linked immunosorbent assay, is desirable. Here, we review recent studies on uEVs dealing with kidney physiology and pathophysiology. Furthermore, we discuss new and exciting developments regarding vesicles, including their role in cell-to-cell communication and the possibility of using vesicles as a therapy for kidney disorders.
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Affiliation(s)
- Mahdi Salih
- Department of Internal Medicine, Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Robert Zietse
- Department of Internal Medicine, Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ewout J. Hoorn
- Department of Internal Medicine, Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
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Abstract
By analysing the pathogenesis of a hereditary hypertensive disease, PHAII (pseudohypoaldosteronism type II), we previously discovered that WNK (with-no-lysine kinase)–OSR1/SPAK (oxidative stress-responsive 1/Ste20-like proline/alanine-rich kinase) cascade regulates NCC (Na–Cl co-transporter) in the DCT (distal convoluted tubules) of the kidney. However, the role of WNK4 in the regulation of NCC remains controversial. To address this, we generated and analysed WNK4−/− mice. Although a moderate decrease in SPAK phosphorylation and a marked increase in WNK1 expression were evident in the kidneys of WNK4−/− mice, the amount of phosphorylated and total NCC decreased to almost undetectable levels, indicating that WNK4 is the major WNK positively regulating NCC, and that WNK1 cannot compensate for WNK4 deficiency in the DCT. Insulin- and low-potassium diet-induced NCC phosphorylation were abolished in WNK4−/− mice, establishing that both signals to NCC were mediated by WNK4. As shown previously, a high-salt diet decreases phosphorylated and total NCC in WNK4+/+ mice via AngII (angiotensin II) and aldosterone suppression. This was not ameliorated by WNK4 knock out, excluding the negative regulation of WNK4 on NCC postulated to be active in the absence of AngII stimulation. Thus, WNK4 is the major positive regulator of NCC in the kidneys. The analyses of WNK4 (with-no-lysine kinase 4) knockout mice help to end a long-standing controversy about the role of WNK4 on NCC (Na–Cl co-transporter) regulations in the kidney. WNK4 is a strong positive regulator of NCC.
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Nagahara K, Abe Y, Hojo A, Dobashi K, Chiga M, Isobe K, Uchida S, Itabashi K. Evaluation of Phosphorylated Urinary Na-Cl Cotransporter Is Potentially Useful in a Patient With Pseudohypoaldosteronism Type II due to Mutation in CUL3. Glob Pediatr Health 2014; 1:2333794X14552899. [PMID: 27335910 PMCID: PMC4804684 DOI: 10.1177/2333794x14552899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Keiko Nagahara
- Department of Pediatrics, Showa University School of Medicine, Tokyo, Japan
| | - Yoshifusa Abe
- Department of Pediatrics, Showa University School of Medicine, Tokyo, Japan
| | - Akira Hojo
- Department of Pediatrics, Showa University School of Medicine, Tokyo, Japan
| | - Kazushige Dobashi
- Department of Pediatrics, Showa University School of Medicine, Tokyo, Japan
| | - Motoko Chiga
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kiyoshi Isobe
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shinichi Uchida
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kazuo Itabashi
- Department of Pediatrics, Showa University School of Medicine, Tokyo, Japan
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Zatz R, Fujihara CK. Discarding the haystack to examine the needles: the potential role of urinary exosome analysis. Am J Physiol Renal Physiol 2013; 305:F1544-5. [DOI: 10.1152/ajprenal.00504.2013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Roberto Zatz
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Clarice Kazue Fujihara
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
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