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Higashihara E, Harada T, Fukuhara H. Juxtaglomerular apparatus-mediated homeostatic mechanisms: therapeutic implication for chronic kidney disease. Expert Opin Pharmacother 2024; 25:819-832. [PMID: 38773961 DOI: 10.1080/14656566.2024.2357188] [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: 01/16/2024] [Accepted: 05/15/2024] [Indexed: 05/24/2024]
Abstract
INTRODUCTION Juxtaglomerular apparatus (JGA)-mediated homeostatic mechanism links to how sodium-glucose cotransporter 2 inhibitors (SGLT2is) slow progression of chronic kidney disease (CKD) and may link to how tolvaptan slows renal function decline in autosomal dominant polycystic kidney disease (ADPKD). AREA COVERED JGA-mediated homeostatic mechanism has been hypothesized based on investigations of tubuloglomerular feedback and renin-angiotensin system. We reviewed clinical trials of SGLT2is and tolvaptan to assess the relationship between this mechanism and these drugs. EXPERT OPINION When sodium load to macula densa (MD) increases, MD increases adenosine production, constricting afferent arteriole (Af-art) and protecting glomeruli. Concurrently, MD signaling suppresses renin secretion, increases urinary sodium excretion, and counterbalances reduced sodium filtration. However, when there is marked increase in sodium load per-nephron, as in advanced CKD, MD adenosine production increases, relaxing Af-art and maintaining sodium homeostasis at the expense of glomeruli. The beneficial effects of tolvaptan on renal function in ADPKD may also depend on the JGA-mediated homeostatic mechanisms since tolvaptan inhibits sodium reabsorption in the thick ascending limb.The JGA-mediated homeostatic mechanism regulates Af-arts, constricting to relaxing according to homeostatic needs. Understanding this mechanism may contribute to the development of pharmacotherapeutic compounds and better care for patients with CKD.
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Affiliation(s)
- Eiji Higashihara
- Department of Urology, Kyorin University School of Medicine, Mitaka, Japan
| | - Takeo Harada
- Department of Renal and Cardiovascular Research, Otsuka Pharmaceutical Co. Ltd, Tokushima, Japan
| | - Hiroshi Fukuhara
- Department of Urology, Kyorin University School of Medicine, Mitaka, Japan
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2
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Diebolt CM, Schaudien D, Junker K, Krasteva-Christ G, Tschernig T, Englisch CN. New insights in the renal distribution profile of TRPC3 - Of mice and men. Ann Anat 2024; 252:152192. [PMID: 37977270 DOI: 10.1016/j.aanat.2023.152192] [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: 10/04/2023] [Revised: 11/01/2023] [Accepted: 11/09/2023] [Indexed: 11/19/2023]
Abstract
Several reports previously investigated the Transient Receptor Potential Canonical subfamily channel 3 (TRPC3) in the kidney. However, most of the conclusions are based on animal samples or cell cultures leaving the door open for human tissue investigations. Moreover, results often disagreed among investigators. Histological description is lacking since most of these studies focused on functional aspects. Nevertheless, the same reports highlighted the potential key-role of TRPC3 in renal disorders. Hence, our interest to investigate the localization of TRPC3 in human kidneys. For this purpose, both healthy mouse and human kidney samples that were originated from tumor nephrectomies have been prepared for immunohistochemical staining using a knockout-validated antibody. A blocking peptide was used to confirm antibody specificity. A normalized weighted diaminobenzidine (DAB) area score between 0 and 3 comparable to a pixelwise H-score was established and employed for semiquantitative analysis. Altogether, our results suggest that glomeruli only express little TRPC3 compared to several segments of the tubular system. Cortical and medullary proximal tubules are stained, although intracortical differences in staining exist in mice. Intermediate tubules, however, are only weakly stained. The distal tubule was studied in three localizations and staining was marked although slightly varying throughout the different subsegments. Finally, the collecting duct was also immunolabeled in both human and mouse tissue. We therefore provide evidence that TRPC3 is expressed in various localizations of both human and mouse samples. We verify results of previous studies and propose until now undescribed localizations of TRPC3 in the mouse but especially and of greater interest in the human kidney. We thereby not only support the translational concept of the TRPC3 channel as key-player in physiology and pathophysiology of the human kidney but also present new potential targets to functional analysis.
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Affiliation(s)
- Coline M Diebolt
- Institute for Anatomy and Cell Biology, Saarland University, Homburg/Saar 66421, Germany
| | - Dirk Schaudien
- Fraunhofer Institute for Toxicology and Experimental Medicine, Hanover 30625, Germany
| | - Kerstin Junker
- Department of Urology and Pediatric Urology, Saarland University Medical Center, Homburg/Saar 66421, Germany
| | | | - Thomas Tschernig
- Institute for Anatomy and Cell Biology, Saarland University, Homburg/Saar 66421, Germany.
| | - Colya N Englisch
- Institute for Anatomy and Cell Biology, Saarland University, Homburg/Saar 66421, Germany
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3
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Huangfu Y, Wang J, Feng J, Zhang ZL. Distal renal tubular system-on-a-chip for studying the pathogenesis of influenza A virus-induced kidney injury. LAB ON A CHIP 2023; 23:4255-4264. [PMID: 37674367 DOI: 10.1039/d3lc00616f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Influenza A viruses typically cause acute respiratory infections in humans. However, virus-induced acute kidney injury (AKI) has dramatically increased mortality. The pathogenesis remains poorly understood due to limited disease models. Here, a distal renal tubular system-on-a-chip (dRTSC) was constructed to explore the pathogenesis. The renal tubule-vascular reabsorption interface was recapitulated by co-culturing the distal renal tubule and peritubular vessel with a collagen-coated porous membrane. To study the pathways of influenza virus entry into the kidney, dynamic tracking of fluorescence-labeled virus-infected blood vessels was performed. For the first time, the virus was shown to enter the kidney rapidly by cell-free transmission without disrupting the vascular barrier. Direct virus infection of renal tubules in dRTSC reveals disruption of tight junctions, microvilli formation, polar distribution of ion transporters, and sodium reabsorption function. This robust platform allows for a straightforward investigation of virus-induced AKI pathogenesis. The combination with single-virus tracking technology provides new insights into understanding influenza virus-induced extra-respiratory disease.
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Affiliation(s)
- Yueyue Huangfu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P.R. China.
| | - Ji Wang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P.R. China.
| | - Jiao Feng
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P.R. China.
| | - Zhi-Ling Zhang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P.R. China.
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4
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Denic A, Gaddam M, Moustafa A, Mullan AF, Luehrs AC, Sharma V, Thompson RH, Smith ML, Alexander MP, Lerman LO, Barisoni L, Rule AD. Tubular and Glomerular Size by Cortex Depth as Predictor of Progressive CKD after Radical Nephrectomy for Tumor. J Am Soc Nephrol 2023; 34:1535-1545. [PMID: 37430426 PMCID: PMC10482069 DOI: 10.1681/asn.0000000000000180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/08/2023] [Indexed: 07/12/2023] Open
Abstract
SIGNIFICANCE STATEMENT Glomerular size differs by cortex depth. Larger nephrons are prognostic of progressive kidney disease, but it is unknown whether this risk differs by cortex depth or by glomeruli versus proximal or distal tubule size. We studied the average minor axis diameter in oval proximal and distal tubules separately and by cortex depth in patients who had radical nephrectomy to remove a tumor from 2019 to 2020. In adjusted analyses, larger glomerular volume in the middle and deep cortex predicted progressive kidney disease. Wider proximal tubular diameter did not predict progressive kidney disease independent of glomerular volume. Wider distal tubular diameter showed a gradient of strength of prediction of progressive kidney disease in the more superficial cortex than in the deep cortex. BACKGROUND Larger nephrons are prognostic of progressive kidney disease, but whether this risk differs by nephron segments or by depth in the cortex is unclear. METHODS We studied patients who underwent radical nephrectomy for a tumor between 2000 and 2019. Large wedge kidney sections were scanned into digital images. We estimated the diameters of proximal and distal tubules by the minor axis of oval tubular profiles and estimated glomerular volume with the Weibel-Gomez stereological model. Analyses were performed separately in the superficial, middle, and deep cortex. Cox proportional hazard models assessed the risk of progressive CKD (dialysis, kidney transplantation, sustained eGFR <10 ml/min per 1.73 m 2 , or a sustained 40% decline from the postnephrectomy baseline eGFR) with glomerular volume or tubule diameters. At each cortical depth, models were unadjusted, adjusted for glomerular volume or tubular diameter, and further adjusted for clinical characteristics (age, sex, body mass index, hypertension, diabetes, postnephrectomy baseline eGFR, and proteinuria). RESULTS Among 1367 patients were 62 progressive CKD events during a median follow-up of 4.5 years. Glomerular volume predicted CKD outcomes at all depths, but only in the middle and deep cortex after adjusted analyses. Proximal tubular diameter also predicted progressive CKD at any depth but not after adjusted analyses. Distal tubular diameter showed a gradient of more strongly predicting progressive CKD in the superficial than deep cortex, even in adjusted analysis. CONCLUSIONS Larger glomeruli are independent predictors of progressive CKD in the deeper cortex, whereas in the superficial cortex, wider distal tubular diameters are an independent predictor of progressive CKD.
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Affiliation(s)
- Aleksandar Denic
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Mrunanjali Gaddam
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Amr Moustafa
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Aidan F. Mullan
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
| | - Anthony C. Luehrs
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
| | - Vidit Sharma
- Department of Urology, Mayo Clinic, Rochester, Minnesota
| | | | - Maxwell L. Smith
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, Arizona
| | - Mariam P. Alexander
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Lilach O. Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Laura Barisoni
- Department of Pathology and Medicine, Duke University, Durham, North Carolina
| | - Andrew D. Rule
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
- Division of Epidemiology, Mayo Clinic, Rochester, Minnesota
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Sørensen SS, Gullaksen S, Vernstrøm L, Ringgaard S, Laustsen C, Funck KL, Laugesen E, Poulsen PL. Evaluation of renal oxygenation by BOLD-MRI in high-risk patients with type 2 diabetes and matched controls. Nephrol Dial Transplant 2023; 38:691-699. [PMID: 35612982 DOI: 10.1093/ndt/gfac186] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Diabetic kidney disease (DKD) accounts for ∼50% of end-stage kidney disease. Renal hypoxia is suggested as a main driver in the pathophysiology underlying chronic DKD. Blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) has made noninvasive investigations of renal oxygenation in humans possible. Whether diabetes per se contributes to measurable changes in renal oxygenation by BOLD-MRI remains to be elucidated. We investigated whether renal oxygenation measured with BOLD-MRI differs between people with type 2 diabetes (T2DM) with normal to moderate chronic kidney disease (CKD) (Stages 1-3A) and matched controls. The repeatability of the BOLD-MRI method was also assessed. METHODS In this matched cross-sectional study, 20 people with T2DM (age 69.2 ± 4.7 years, duration of diabetes 10.5 ± 6.7 years, male 55.6%) and 20 matched nondiabetic controls (mean age 68.8 ± 5.4 years, male 55.%) underwent BOLD-MRI analysed with the 12-layer concentric object method (TLCO). To investigate the repeatability, seven in the T2DM group and nine in the control group were scanned twice. RESULTS A significant reduction in renal oxygenation from the cortex to medulla was found in both groups (P < .01) but no intergroup difference was detected [0.71/s (95% confidence interval -0.28-1.7), P = .16]. The median intraindividual coefficient of variation (CV) varied from 1.2% to 7.0%. CONCLUSION T2DM patients with normal to moderate CKD do not seem to have lower renal oxygenation when measured with BOLD-MRI and TLCO. BOLD-MRI has a low intraindividual CV and seems like a reliable method for investigation of renal oxygenation in T2DM.
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Affiliation(s)
- Steffen S Sørensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | - Søren Gullaksen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | - Liv Vernstrøm
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | | | | | - Kristian L Funck
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | - Esben Laugesen
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
| | - Per L Poulsen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Steno Diabetes Center, Aarhus University Hospital, Aarhus, Denmark
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6
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Peng Z, Wang H, Zheng J, Wang J, Xiang Y, Liu C, Ji M, Liu H, Pan L, Qin X, Qu X. Is the proximal tubule the focus of tubulointerstitial fibrosis? Heliyon 2023; 9:e13508. [PMID: 36846656 PMCID: PMC9950842 DOI: 10.1016/j.heliyon.2023.e13508] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/15/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023] Open
Abstract
Tubulointerstitial fibrosis (TIF), a common end result of almost all progressive chronic kidney diseases (CKD), is also the best predictor of kidney survival. Almost all cells in the kidney are involved in the progression of TIF. Myofibroblasts, the primary producers of extracellular matrix, have previously received a great deal of attention; however, a large body of emerging evidence reveals that proximal tubule (PT) plays a central role in TIF progression. In response to injury, renal tubular epithelial cells (TECs) transform into inflammatory and fibroblastic cells, producing various bioactive molecules that drive interstitial inflammation and fibrosis. Here we reviewed the increasing evidence for the key role of the PT in promoting TIF in tubulointerstitial and glomerular injury and discussed the therapeutic targets and carrier systems involving the PT that holds particular promise for treating patients with fibrotic nephropathy.
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Affiliation(s)
- Zhi Peng
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha 410008, Hunan, China
| | - Hui Wang
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha 410008, Hunan, China
| | - Jiaoyun Zheng
- Department of Pathology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jie Wang
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha 410008, Hunan, China
| | - Yang Xiang
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha 410008, Hunan, China
| | - Chi Liu
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha 410008, Hunan, China
| | - Ming Ji
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha 410008, Hunan, China
| | - Huijun Liu
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha 410008, Hunan, China
| | - Lang Pan
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha 410008, Hunan, China
| | - Xiaoqun Qin
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha 410008, Hunan, China
| | - Xiangping Qu
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha 410008, Hunan, China,Corresponding author.
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7
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Mao ZH, Gao ZX, Liu Y, Liu DW, Liu ZS, Wu P. Single-cell transcriptomics: A new tool for studying diabetic kidney disease. Front Physiol 2023; 13:1053850. [PMID: 36685214 PMCID: PMC9846140 DOI: 10.3389/fphys.2022.1053850] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 12/16/2022] [Indexed: 01/05/2023] Open
Abstract
The kidney is a complex organ comprising various functional partitions and special cell types that play important roles in maintaining homeostasis in the body. Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease and is an independent risk factor for cardiovascular diseases. Owing to the complexity and heterogeneity of kidney structure and function, the mechanism of DKD development has not been fully elucidated. Single-cell sequencing, including transcriptomics, epigenetics, metabolomics, and proteomics etc., is a powerful technology that enables the analysis of specific cell types and states, specifically expressed genes or pathways, cell differentiation trajectories, intercellular communication, and regulation or co-expression of genes in various diseases. Compared with other omics, RNA sequencing is a more developed technique with higher utilization of tissues or samples. This article reviewed the application of single-cell transcriptomics in the field of DKD and highlighted the key signaling pathways in specific tissues or cell types involved in the occurrence and development of DKD. The comprehensive understanding of single-cell transcriptomics through single-cell RNA-seq and single-nucleus RNA-seq will provide us new insights into the pathogenesis and treatment strategy of various diseases including DKD.
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Affiliation(s)
- Zi-Hui Mao
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China,Institute of Nephrology, Zhengzhou University, Zhengzhou, China,Henan Province Research Center for Kidney Disease, Zhengzhou, China,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Zhong-Xiuzi Gao
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China,Institute of Nephrology, Zhengzhou University, Zhengzhou, China,Henan Province Research Center for Kidney Disease, Zhengzhou, China,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Yong Liu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China,Institute of Nephrology, Zhengzhou University, Zhengzhou, China,Henan Province Research Center for Kidney Disease, Zhengzhou, China,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Dong-Wei Liu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China,Institute of Nephrology, Zhengzhou University, Zhengzhou, China,Henan Province Research Center for Kidney Disease, Zhengzhou, China,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China
| | - Zhang-Suo Liu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China,Institute of Nephrology, Zhengzhou University, Zhengzhou, China,Henan Province Research Center for Kidney Disease, Zhengzhou, China,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China,*Correspondence: Peng Wu, ; Zhang-Suo Liu,
| | - Peng Wu
- Traditional Chinese Medicine Integrated Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China,Institute of Nephrology, Zhengzhou University, Zhengzhou, China,Henan Province Research Center for Kidney Disease, Zhengzhou, China,Key Laboratory of Precision Diagnosis and Treatment for Chronic Kidney Disease in Henan Province, Zhengzhou, China,*Correspondence: Peng Wu, ; Zhang-Suo Liu,
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8
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Englisch CN, Paulsen F, Tschernig T. TRPC Channels in the Physiology and Pathophysiology of the Renal Tubular System: What Do We Know? Int J Mol Sci 2022; 24:ijms24010181. [PMID: 36613622 PMCID: PMC9820145 DOI: 10.3390/ijms24010181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/12/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022] Open
Abstract
The study of transient receptor potential (TRP) channels has dramatically increased during the past few years. TRP channels function as sensors and effectors in the cellular adaptation to environmental changes. Here, we review literature investigating the physiological and pathophysiological roles of TRPC channels in the renal tubular system with a focus on TRPC3 and TRPC6. TRPC3 plays a key role in Ca2+ homeostasis and is involved in transcellular Ca2+ reabsorption in the proximal tubule and the collecting duct. TRPC3 also conveys the osmosensitivity of principal cells of the collecting duct and is implicated in vasopressin-induced membrane translocation of AQP-2. Autosomal dominant polycystic kidney disease (ADPKD) can often be attributed to mutations of the PKD2 gene. TRPC3 is supposed to have a detrimental role in ADPKD-like conditions. The tubule-specific physiological functions of TRPC6 have not yet been entirely elucidated. Its pathophysiological role in ischemia-reperfusion injuries is a subject of debate. However, TRPC6 seems to be involved in tumorigenesis of renal cell carcinoma. In summary, TRPC channels are relevant in multiples conditions of the renal tubular system. There is a need to further elucidate their pathophysiology to better understand certain renal disorders and ultimately create new therapeutic targets to improve patient care.
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Affiliation(s)
- Colya N. Englisch
- Institute of Anatomy and Cell Biology, Saarland University, 66421 Homburg/Saar, Germany
| | - Friedrich Paulsen
- Institute of Functional and Clinical Anatomy, Friedrich Alexander University Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Thomas Tschernig
- Institute of Anatomy and Cell Biology, Saarland University, 66421 Homburg/Saar, Germany
- Correspondence: ; Tel.: +49-6841-1626-100
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9
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Castañeda-Bueno M, Ellison DH. Blood pressure effects of sodium transport along the distal nephron. Kidney Int 2022; 102:1247-1258. [PMID: 36228680 PMCID: PMC9754644 DOI: 10.1016/j.kint.2022.09.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/22/2022] [Accepted: 09/01/2022] [Indexed: 11/06/2022]
Abstract
The mammalian distal nephron is a target of highly effective antihypertensive drugs. Genetic variants that alter its transport activity are also inherited causes of high or low blood pressure, clearly establishing its central role in human blood pressure regulation. Much has been learned during the past 25 years about salt transport along this nephron segment, spurred by the cloning of major transport proteins and the discovery of disease-causing genetic variants. Recognition is increasing that substantial cellular and segmental heterogeneity is present along this segment, with electroneutral sodium transport dominating more proximal segments and electrogenic sodium transport dominating more distal segments. Coupled with recent insights into factors that modulate transport along these segments, we now understand one important mechanism by which dietary potassium intake influences sodium excretion and blood pressure. This finding has solved the aldosterone paradox, by demonstrating how aldosterone can be both kaliuretic, when plasma potassium is elevated, and anti-natriuretic, when extracellular fluid volume is low. However, what also has become clear is that aldosterone itself only stimulates a portion of the mineralocorticoid receptors along this segment, with the others being activated by glucocorticoid hormones instead. These recent insights provide an increasingly clear picture of how this short nephron segment contributes to blood pressure homeostasis and have important implications for hypertension prevention and treatment.
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Affiliation(s)
- María Castañeda-Bueno
- Department of Nephrology and Mineral Metabolism, National Institute of Medical Sciences and Nutrition, Salvador Zubirán, Tlalpan, Mexico City, Mexico
| | - David H Ellison
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon, USA; Oregon Clinical & Translational Research Institute, Oregon Health & Science University, Portland, Oregon, USA; LeDucq Transatlantic Network of Excellence, Portland, Oregon, USA; Renal Section, VA Portland Healthcare System, Portland, Oregon, USA.
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10
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Viering D, Schlingmann KP, Hureaux M, Nijenhuis T, Mallett A, Chan MM, van Beek A, van Eerde AM, Coulibaly JM, Vallet M, Decramer S, Pelletier S, Klaus G, Kömhoff M, Beetz R, Patel C, Shenoy M, Steenbergen EJ, Anderson G, Bongers EM, Bergmann C, Panneman D, Rodenburg RJ, Kleta R, Houillier P, Konrad M, Vargas-Poussou R, Knoers NV, Bockenhauer D, de Baaij JH. Gitelman-Like Syndrome Caused by Pathogenic Variants in mtDNA. J Am Soc Nephrol 2022; 33:305-325. [PMID: 34607911 PMCID: PMC8819995 DOI: 10.1681/asn.2021050596] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 09/06/2021] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Gitelman syndrome is the most frequent hereditary salt-losing tubulopathy characterized by hypokalemic alkalosis and hypomagnesemia. Gitelman syndrome is caused by biallelic pathogenic variants in SLC12A3, encoding the Na+-Cl- cotransporter (NCC) expressed in the distal convoluted tubule. Pathogenic variants of CLCNKB, HNF1B, FXYD2, or KCNJ10 may result in the same renal phenotype of Gitelman syndrome, as they can lead to reduced NCC activity. For approximately 10 percent of patients with a Gitelman syndrome phenotype, the genotype is unknown. METHODS We identified mitochondrial DNA (mtDNA) variants in three families with Gitelman-like electrolyte abnormalities, then investigated 156 families for variants in MT-TI and MT-TF, which encode the transfer RNAs for phenylalanine and isoleucine. Mitochondrial respiratory chain function was assessed in patient fibroblasts. Mitochondrial dysfunction was induced in NCC-expressing HEK293 cells to assess the effect on thiazide-sensitive 22Na+ transport. RESULTS Genetic investigations revealed four mtDNA variants in 13 families: m.591C>T (n=7), m.616T>C (n=1), m.643A>G (n=1) (all in MT-TF), and m.4291T>C (n=4, in MT-TI). Variants were near homoplasmic in affected individuals. All variants were classified as pathogenic, except for m.643A>G, which was classified as a variant of uncertain significance. Importantly, affected members of six families with an MT-TF variant additionally suffered from progressive chronic kidney disease. Dysfunction of oxidative phosphorylation complex IV and reduced maximal mitochondrial respiratory capacity were found in patient fibroblasts. In vitro pharmacological inhibition of complex IV, mimicking the effect of the mtDNA variants, inhibited NCC phosphorylation and NCC-mediated sodium uptake. CONCLUSION Pathogenic mtDNA variants in MT-TF and MT-TI can cause a Gitelman-like syndrome. Genetic investigation of mtDNA should be considered in patients with unexplained Gitelman syndrome-like tubulopathies.
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Affiliation(s)
- Daan Viering
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Karl P. Schlingmann
- Department of General Pediatrics, University Children’s Hospital, Münster, Germany
| | - Marguerite Hureaux
- Reference Center for Hereditary Kidney and Childhood Diseases (Maladies rénales héréditaires de l'enfant et de l'adulte [MARHEA]), Paris, France,Department of Genetics, Assistance Publique Hôpitaux de Paris, Hôpital Européen Georges-Pompidou, Paris, France
| | - Tom Nijenhuis
- Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Andrew Mallett
- Department of Renal Medicine, Townsville University Hospital, Townsville, Australia,Queensland Conjoint Renal Genetics Service – Genetic Health Queensland, Royal Brisbane and Women’s Hospital, Brisbane, Australia
| | - Melanie M.Y. Chan
- Department of Renal Medicine, University College London, London, United Kingdom
| | - André van Beek
- Department of Endocrinology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | | | | | - Marion Vallet
- Department of Physiological Functional Investigations, Centre Hospitalier Universitaire de Toulouse, Université Paul Sabatier, Toulouse, France
| | - Stéphane Decramer
- Pediatric Nephrology, Internal Medicine and Rheumatology, Southwest Renal Rare Diseases Centre (SORARE), University Children's Hospital, Toulouse, France
| | - Solenne Pelletier
- Department of Nephrology, University Hospital–Lyon Sud, Lyon, France
| | - Günter Klaus
- Kuratorium für Heimdialyse Pediatric Kidney Center, Marburg, Germany
| | - Martin Kömhoff
- University Children's Hospital, Philipps-University, Marburg, Germany
| | - Rolf Beetz
- Johannes Gutenberg Universität Mainz, Zentrum für Kinder- und Jugendmedizin, Mainz, Germany
| | - Chirag Patel
- Queensland Conjoint Renal Genetics Service – Genetic Health Queensland, Royal Brisbane and Women’s Hospital, Brisbane, Australia
| | - Mohan Shenoy
- Department of Paediatric Nephrology, Royal Manchester Children’s Hospital, Manchester, United Kingdom
| | - Eric J. Steenbergen
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Glenn Anderson
- Department of Pathology, Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust, London, United Kingdom
| | - Ernie M.H.F. Bongers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Carsten Bergmann
- Limbach Genetics, Medizinische Genetik Mainz, Prof. Bergmann & Kollegen, Mainz, Germany,Department of Medicine, Division of Nephrology, University Hospital Freiburg, Germany
| | - Daan Panneman
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Richard J. Rodenburg
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Robert Kleta
- Department of Renal Medicine, University College London, London, United Kingdom,Department of Paediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Pascal Houillier
- Reference Center for Hereditary Kidney and Childhood Diseases (Maladies rénales héréditaires de l'enfant et de l'adulte [MARHEA]), Paris, France,Centre de Recherche des Cordeliers, Sorbonne Université, Institut National de la Santé et de Recherche Médicale (INSERM), Université de Paris, Centre National de la Recherche Scientifique (CNRS), Paris, France,Department of Physiology, Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Paris, France
| | - Martin Konrad
- Department of General Pediatrics, University Children’s Hospital, Münster, Germany
| | - Rosa Vargas-Poussou
- Reference Center for Hereditary Kidney and Childhood Diseases (Maladies rénales héréditaires de l'enfant et de l'adulte [MARHEA]), Paris, France,Department of Genetics, Assistance Publique Hôpitaux de Paris, Hôpital Européen Georges-Pompidou, Paris, France,Centre de Recherche des Cordeliers, Sorbonne Université, Institut National de la Santé et de Recherche Médicale (INSERM), Université de Paris, Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Nine V.A.M. Knoers
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Detlef Bockenhauer
- Department of Renal Medicine, University College London, London, United Kingdom,Renal Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Jeroen H.F. de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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11
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Tsilosani A, Gao C, Zhang W. Aldosterone-Regulated Sodium Transport and Blood Pressure. Front Physiol 2022; 13:770375. [PMID: 35197862 PMCID: PMC8859437 DOI: 10.3389/fphys.2022.770375] [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: 09/03/2021] [Accepted: 01/06/2022] [Indexed: 11/13/2022] Open
Abstract
Aldosterone is a major mineralocorticoid steroid hormone secreted by glomerulosa cells in the adrenal cortex. It regulates a variety of physiological responses including those to oxidative stress, inflammation, fluid disruption, and abnormal blood pressure through its actions on various tissues including the kidney, heart, and the central nervous system. Aldosterone synthesis is primarily regulated by angiotensin II, K+ concentration, and adrenocorticotrophic hormone. Elevated serum aldosterone levels increase blood pressure largely by increasing Na+ re-absorption in the kidney through regulating transcription and activity of the epithelial sodium channel (ENaC). This review focuses on the signaling pathways involved in aldosterone synthesis and its effects on Na+ reabsorption through ENaC.
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Affiliation(s)
- Akaki Tsilosani
- Department of Regenerative & Cancer Cell Biology, Albany Medical College, Albany, NY, United States
| | - Chao Gao
- Department of Regenerative & Cancer Cell Biology, Albany Medical College, Albany, NY, United States
| | - Wenzheng Zhang
- Department of Regenerative & Cancer Cell Biology, Albany Medical College, Albany, NY, United States
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12
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Barany A, Shaughnessy CA, Pelis RM, Fuentes J, Mancera JM, McCormick SD. Tissue and salinity specific Na +/Cl - cotransporter (NCC) orthologues involved in the adaptive osmoregulation of sea lamprey (Petromyzon marinus). Sci Rep 2021; 11:22698. [PMID: 34811419 PMCID: PMC8608846 DOI: 10.1038/s41598-021-02125-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 10/29/2021] [Indexed: 12/12/2022] Open
Abstract
Two orthologues of the gene encoding the Na+-Cl− cotransporter (NCC), termed ncca and nccb, were found in the sea lamprey genome. No gene encoding the Na+-K+-2Cl− cotransporter 2 (nkcc2) was identified. In a phylogenetic comparison among other vertebrate NCC and NKCC sequences, the sea lamprey NCCs occupied basal positions within the NCC clades. In freshwater, ncca mRNA was found only in the gill and nccb only in the intestine, whereas both were found in the kidney. Intestinal nccb mRNA levels increased during late metamorphosis coincident with salinity tolerance. Acclimation to seawater increased nccb mRNA levels in the intestine and kidney. Electrophysiological analysis of intestinal tissue ex vivo showed this tissue was anion absorptive. After seawater acclimation, the proximal intestine became less anion absorptive, whereas the distal intestine remained unchanged. Luminal application of indapamide (an NCC inhibitor) resulted in 73% and 30% inhibition of short-circuit current (Isc) in the proximal and distal intestine, respectively. Luminal application of bumetanide (an NKCC inhibitor) did not affect intestinal Isc. Indapamide also inhibited intestinal water absorption. Our results indicate that NCCb is likely the key ion cotransport protein for ion uptake by the lamprey intestine that facilitates water absorption in seawater. As such, the preparatory increases in intestinal nccb mRNA levels during metamorphosis of sea lamprey are likely critical to development of whole animal salinity tolerance.
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Affiliation(s)
- A Barany
- Department of Biology, Faculty of Marine and Environmental Sciences, Campus de Excelencia Internacional del Mar (CEI-MAR), University of Cádiz, Puerto Real, 11519, Cádiz, Spain. .,Centre of Marine Sciences (CCMar), University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal. .,Conte Anadromous Fish Research Laboratory, Eastern Ecological Science Center, U.S. Geological Survey, Turners Falls, MA, 01376, USA.
| | - C A Shaughnessy
- Conte Anadromous Fish Research Laboratory, Eastern Ecological Science Center, U.S. Geological Survey, Turners Falls, MA, 01376, USA.,Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - R M Pelis
- Department of Pharmaceutical Sciences, Binghamton University, State University of New York, Johnson City, NY, 13790, USA
| | - J Fuentes
- Centre of Marine Sciences (CCMar), University of Algarve, Campus de Gambelas, 8005-139, Faro, Portugal
| | - J M Mancera
- Department of Biology, Faculty of Marine and Environmental Sciences, Campus de Excelencia Internacional del Mar (CEI-MAR), University of Cádiz, Puerto Real, 11519, Cádiz, Spain
| | - S D McCormick
- Conte Anadromous Fish Research Laboratory, Eastern Ecological Science Center, U.S. Geological Survey, Turners Falls, MA, 01376, USA.,Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA, 01003, USA
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13
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Abstract
Magnesium (Mg2+) is the second most abundant intracellular and fourth extracellular cation found in the body and is involved in a wide range of functions in the human cell and human physiology. Its role in most of the enzyme processes (ATP-ases)-stabilisation of nucleic acids (DNA, RNA), regulation of calcium and potassium ion channels, proliferation, glucose metabolism and apoptosis-make it one of the most important cations in the cell. Three pathogenetic mechanisms are mainly implicated in the development of hypomagnesaemia: reduced food intake, decreased intestinal absorption and increased renal excretion of Mg2+. This review presents the function of Mg2+, how it is handled in the kidney and the drugs that cause hypomagnesaemia. The frequency and the number of drugs like diuretics and proton-pump inhibitors (PPIs) that are used daily in medical practice are discussed in order to prevent and treat adverse effects by providing an insight into Mg2+ homeostasis.
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Affiliation(s)
- Periklis Katopodis
- Department of Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, London, UB8 3PH, UK.
| | - Emmanouil Karteris
- Department of Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, London, UB8 3PH, UK
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14
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Liamis G, Hoorn EJ, Florentin M, Milionis H. An overview of diagnosis and management of drug-induced hypomagnesemia. Pharmacol Res Perspect 2021; 9:e00829. [PMID: 34278747 PMCID: PMC8287009 DOI: 10.1002/prp2.829] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 03/18/2021] [Accepted: 06/01/2021] [Indexed: 12/29/2022] Open
Abstract
Magnesium (Mg) is commonly addressed as the "forgotten ion" in medicine. Nonetheless, hypomagnesemia should be suspected in clinical practice in patients with relevant symptomatology and also be considered a predisposing factor for the development of other electrolyte disturbances. Furthermore, chronic hypomagnesemia has been associated with diabetes mellitus and cardiovascular disease. Hypomagnesemia as a consequence of drug therapy is relatively common, with the list of drugs inducing low serum Mg levels expanding. Culprit medications linked to hypomagnesemia include antibiotics (e.g. aminoglycosides, amphotericin B), diuretics, antineoplastic drugs (cisplatin and cetuximab), calcineurin inhibitors, and proton pump inhibitors. In recent years, the mechanisms of drug-induced hypomagnesemia have been unraveled through the discovery of key Mg transporters in the gut and kidney. This narrative review of available literature focuses on the pathogenetic mechanisms underlying drug-induced hypomagnesemia in order to increase the insight of clinicians toward early diagnosis and effective management.
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Affiliation(s)
- George Liamis
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
| | - Ewout J Hoorn
- Division of Nephrology and Transplantation, Department of Internal Medicine, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Matilda Florentin
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
| | - Haralampos Milionis
- Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
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15
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Bassi V, Fattoruso O. The Combined Use of Fractional Urate and Potassium Excretion in the Diagnosis of Diuretic-Induced Hyponatremia. Cureus 2021; 13:e15308. [PMID: 34221761 PMCID: PMC8238019 DOI: 10.7759/cureus.15308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Introduction Thiazide and loop-diuretics are among the most widely used drugs in the therapy of hypertension and chronic heart failure. Furthermore, hyponatremia is the most prevalent electrolyte imbalance affecting up to 25-30% of hospitalized patients while syndrome of inappropriate antidiuresis (SIAD) is involving approximately 35% of hyponatraemic inpatients. Clinical and laboratoristic algorithms support the differential diagnosis of hypotonic hyponatremia in actual guidelines of SIAD, but a potential bias is represented by the misleading clinical assessment of the extracellular volume status in diuretic-treated patients where the necessity of withdrawal of the therapy is mandatory. We investigated the role of fractional uric acid and potassium excretion (FEUA and FEK) in the differential diagnosis of hypotonic hyponatremia in SIAD and diuretic-treated patients. Methods Thirty-six SIAD, 30 thiazide-induced hyponatremia (TIH), and 32 diuretic-induced hyponatremia (DIH) patients were investigated calculating FEUA and FEK values in receiver operating characteristic (ROC) curve analysis to improve the diagnostic approach of hypotonic hyponatremia. Results The combination of the two investigated markers showed different significative results generating patterns useful to discriminate among the three different hyponatremic groups. Conclusion The fractional uric acid and potassium excretion could be considered as new markers in the diagnostic approach of hyponatremic diuretic-treated patients where classical algorithms could fail.
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Affiliation(s)
- Vincenzo Bassi
- Unità Operativa Complessa (UOC) di Medicina Generale e Lungodegenza, San Giovanni Bosco Hospital, Azienda Sanitaria Locale (ASL) Napoli 1 Centro, Naples, ITA
| | - Olimpia Fattoruso
- Unità Operativa Complessa (UOC) di Patologia Generale, San Giovanni Bosco Hospital, Azienda Sanitaria Locale (ASL) Napoli 1 Centro, Naples, ITA
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16
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Downie ML, Lopez Garcia SC, Kleta R, Bockenhauer D. Inherited Tubulopathies of the Kidney: Insights from Genetics. Clin J Am Soc Nephrol 2021; 16:620-630. [PMID: 32238367 PMCID: PMC8092065 DOI: 10.2215/cjn.14481119] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The kidney tubules provide homeostasis by maintaining the external milieu that is critical for proper cellular function. Without homeostasis, there would be no heartbeat, no muscle movement, no thought, sensation, or emotion. The task is achieved by an orchestra of proteins, directly or indirectly involved in the tubular transport of water and solutes. Inherited tubulopathies are characterized by impaired function of one or more of these specific transport molecules. The clinical consequences can range from isolated alterations in the concentration of specific solutes in blood or urine to serious and life-threatening disorders of homeostasis. In this review, we focus on genetic aspects of the tubulopathies and how genetic investigations and kidney physiology have crossfertilized each other and facilitated the identification of these disorders and their molecular basis. In turn, clinical investigations of genetically defined patients have shaped our understanding of kidney physiology.
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Affiliation(s)
- Mallory L. Downie
- Department of Renal Medicine, University College London, London, United Kingdom,Department of Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Sergio C. Lopez Garcia
- Department of Renal Medicine, University College London, London, United Kingdom,Department of Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Robert Kleta
- Department of Renal Medicine, University College London, London, United Kingdom,Department of Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Detlef Bockenhauer
- Department of Renal Medicine, University College London, London, United Kingdom,Department of Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
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17
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Chen L, Chou CL, Knepper MA. Targeted Single-Cell RNA-seq Identifies Minority Cell Types of Kidney Distal Nephron. J Am Soc Nephrol 2021; 32:886-896. [PMID: 33769948 PMCID: PMC8017539 DOI: 10.1681/asn.2020101407] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 01/03/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Proximal tubule cells dominate the kidney parenchyma numerically, although less abundant cell types of the distal nephron have disproportionate roles in water and electrolyte balance. METHODS Coupling of a FACS-based enrichment protocol with single-cell RNA-seq profiled the transcriptomes of 9099 cells from the thick ascending limb (CTAL)/distal convoluted tubule (DCT) region of the mouse nephron. RESULTS Unsupervised clustering revealed Slc12a3 +/Pvalb + and Slc12a3 +/Pvalb - cells, identified as DCT1 and DCT2 cells, respectively. DCT1 cells appear to be heterogeneous, with orthogonally variable expression of Slc8a1, Calb1, and Ckb. An additional DCT1 subcluster showed marked enrichment of cell cycle-/cell proliferation-associated mRNAs (e.g., Mki67, Stmn1, and Top2a), which fit with the known plasticity of DCT cells. No DCT2-specific transcripts were found. DCT2 cells contrast with DCT1 cells by expression of epithelial sodium channel β- and γ-subunits and much stronger expression of transcripts associated with calcium transport (Trpv5, Calb1, S100g, and Slc8a1). Additionally, scRNA-seq identified three distinct CTAL (Slc12a1 +) cell subtypes. One of these expressed Nos1 and Avpr1a, consistent with macula densa cells. The other two CTAL clusters were distinguished by Cldn10 and Ptger3 in one and Cldn16 and Foxq1 in the other. These two CTAL cell types were also distinguished by expression of alternative Iroquois homeobox transcription factors, with Irx1 and Irx2 in the Cldn10 + CTAL cells and Irx3 in the Cldn16 + CTAL cells. CONCLUSIONS Single-cell transcriptomics revealed unexpected diversity among the cells of the distal nephron in mouse. Web-based data resources are provided for the single-cell data.
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Affiliation(s)
- Lihe Chen
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
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18
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Kortenoeven MLA, Cheng L, Wu Q, Fenton RA. An in vivo protein landscape of the mouse DCT during high dietary K + or low dietary Na + intake. Am J Physiol Renal Physiol 2021; 320:F908-F921. [PMID: 33779313 DOI: 10.1152/ajprenal.00064.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The hormone aldosterone is essential for maintaining K+ and Na+ balance and controlling blood pressure. Aldosterone has different effects if it is secreted due to hypovolemia or hyperkalemia. The kidney distal convoluted tubule (DCT) is believed to play a central role in mediating the differential responses to aldosterone. To determine the alterations in the DCT that may be responsible for these effects, male mice with green fluorescent protein expression specifically in the DCT were maintained on diets containing low NaCl (hypovolemic state) or high potassium citrate (hyperkalemic state) for 4 days, and DCT cells were isolated using fluorescence-activated cell sorting. This pure population of DCT cells was subjected to analysis by liquid chromatography-coupled tandem mass spectrometry. Over 3,000 proteins were identified in the DCT, creating the first proteome of the mouse DCT. Of the identified proteins, 210 proteins were altered in abundance following a low-NaCl diet and 625 proteins following the high-K+ diet. Many of these changes were not detectable by analyzing whole kidney samples from the same animals. When comparing responses to high-K+ versus low-Na+ diets, protein translation, chaperone-mediated protein folding, and protein ubiquitylation were likely to be significantly altered in the DCT subsequent to a high-K+ diet. In conclusion, this study defines an in vivo protein landscape of the DCT in male mice following either a low-NaCl or a high-K+ diet and acts as an essential resource for the kidney research community.NEW & NOTEWORTHY The mineralocorticoid aldosterone, essential for maintaining body K+ and Na+ balance, has different effects if secreted due to hypovolemia or hyperkalemia. Here, we used proteomics to profile kidney distal convoluted tubule (DCT) cells isolated by a novel FACS approach from mice fed a low-Na+ diet (mimicking hypovolemia) or a high-K+ diet (mimicking hyperkalemia). The study provides the first in-depth proteome of the mouse DCT and insights into how it is physiologically regulated.
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Affiliation(s)
- Marleen L A Kortenoeven
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark.,Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Lei Cheng
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Qi Wu
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
| | - Robert A Fenton
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark
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19
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Govers LP, Toka HR, Hariri A, Walsh SB, Bockenhauer D. Mitochondrial DNA mutations in renal disease: an overview. Pediatr Nephrol 2021; 36:9-17. [PMID: 31925537 PMCID: PMC7701126 DOI: 10.1007/s00467-019-04404-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 10/12/2019] [Accepted: 10/16/2019] [Indexed: 12/28/2022]
Abstract
Kidneys have a high energy demand to facilitate the reabsorption of the glomerular filtrate. For this reason, renal cells have a high density of mitochondria. Mitochondrial cytopathies can be the result of a mutation in both mitochondrial and nuclear DNA. Mitochondrial dysfunction can lead to a variety of renal manifestations. Examples of tubular manifestations are renal Fanconi Syndrome, which is often found in patients diagnosed with Kearns-Sayre and Pearson's marrow-pancreas syndrome, and distal tubulopathies, which result in electrolyte disturbances such as hypomagnesemia. Nephrotic syndrome can be a glomerular manifestation of mitochondrial dysfunction and is typically associated with focal segmental glomerular sclerosis on histology. Tubulointerstitial nephritis can also be seen in mitochondrial cytopathies and may lead to end-stage renal disease. The underlying mechanisms of these cytopathies remain incompletely understood; therefore, current therapies focus mainly on symptom relief. A better understanding of the molecular disease mechanisms is critical in order to improve treatments.
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Affiliation(s)
- Larissa P Govers
- Department of Renal Medicine, University College London, London, UK
| | - Hakan R Toka
- Manatee Kidney Diseases Consultants, Bradenton, USA
| | - Ali Hariri
- Clinical Development, Sanofi Rare Disease, Boston, USA
| | - Stephen B Walsh
- Department of Renal Medicine, University College London, London, UK
| | - Detlef Bockenhauer
- Department of Renal Medicine, University College London, London, UK.
- Renal Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, Great Ormond Street, London, UK.
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20
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Talmatamar A, Chaabane I, Salem S, Touati H, Remana S, Chevalier C, Moudilou EN, Exbrayat JM, Barka-Dahane Z. Kidney functional morphology variations between spring and winter in the Saharan male lizard Uromastyx acanthinura (Sauria, Agamidae), with special reference to body water economy. Tissue Cell 2020; 67:101448. [PMID: 33130457 DOI: 10.1016/j.tice.2020.101448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 12/05/2022]
Abstract
To better understand the adaptive mechanisms in Uromastyx acanthinura to the seasonal variations in the arid environment, the present study aimed to explore the kidney functional morphology involved in body water economy. These investigations were carried out by the histological, histochemical and immuno-histochemical methods using conventional light microscopy. The glomeruli number is estimated at 2000 per kidney. The glomeruli size is rather small and decreases significantly in winter. Interestingly, the proximal convoluted tubule (PCT) is long and divided into two different segments which is one of the particularities of this species. Both of the distal convoluted tubule (DCT), connecting tubule (CnT) and collecting duct (CD) epithelium contains mucous cells. The nature and intensity of these mucous secretions vary according to seasons. The evident hypertrophy of the secondary collecting duct (SCD) and tertiary collecting duct (TCD) epithelium is related to the high secretory activity during spring, corresponding to the sexual segment of kidney (SSK). Labeling with anti α-smooth muscle actin-1 showed a thick layer of mucularis surrounded the entire CD. Also, the mesangium of glomeruli contains myofibroblasts. All these renal structural characteristics involved in body water economy may be considered as an adaptive mechanisms of U. acanthinura to resist to dehydration and cope with seasonal variations in the arid environment.
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Affiliation(s)
- Amina Talmatamar
- Houari Boumediene University of Sciences and Technology, Neurobiology Team, Laboratory of Biology and Physiology of Organisms. BP 32 El-Alia, 16111, Algiers, Algeria.
| | - Isma Chaabane
- Houari Boumediene University of Sciences and Technology, Neurobiology Team, Laboratory of Biology and Physiology of Organisms. BP 32 El-Alia, 16111, Algiers, Algeria.
| | - Sabiha Salem
- Houari Boumediene University of Sciences and Technology, Neurobiology Team, Laboratory of Biology and Physiology of Organisms. BP 32 El-Alia, 16111, Algiers, Algeria.
| | - Hanane Touati
- Houari Boumediene University of Sciences and Technology, Neurobiology Team, Laboratory of Biology and Physiology of Organisms. BP 32 El-Alia, 16111, Algiers, Algeria.
| | - Soumia Remana
- Houari Boumediene University of Sciences and Technology, Neurobiology Team, Laboratory of Biology and Physiology of Organisms. BP 32 El-Alia, 16111, Algiers, Algeria.
| | - Christine Chevalier
- UR Confluence, Sciences et Humanités, Laboratoire Bioscience, Technologies, Ethique-UCLy, 10 place des Archives, 69288, Lyon Cedex 02, France.
| | - Elara N Moudilou
- UR Confluence, Sciences et Humanités, Laboratoire Bioscience, Technologies, Ethique-UCLy, 10 place des Archives, 69288, Lyon Cedex 02, France.
| | - Jean-Marie Exbrayat
- Catholic University of Lyon, UDL and Ecole Pratique des Hautes Etudes, PSL, France.
| | - Zohra Barka-Dahane
- Houari Boumediene University of Sciences and Technology, Neurobiology Team, Laboratory of Biology and Physiology of Organisms. BP 32 El-Alia, 16111, Algiers, Algeria.
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21
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Calcium-Sensing Receptor and Regulation of WNK Kinases in the Kidney. Cells 2020; 9:cells9071644. [PMID: 32659887 PMCID: PMC7407487 DOI: 10.3390/cells9071644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/01/2020] [Accepted: 07/06/2020] [Indexed: 12/27/2022] Open
Abstract
The kidney is essential for systemic calcium homeostasis. Urinary calcium excretion can be viewed as an integrative renal response to endocrine and local stimuli. The extracellular calcium-sensing receptor (CaSR) elicits a number of adaptive reactions to increased plasma Ca2+ levels including the control of parathyroid hormone release and regulation of the renal calcium handling. Calcium reabsorption in the distal nephron of the kidney is functionally coupled to sodium transport. Apart from Ca2+ transport systems, CaSR signaling affects relevant distal Na+-(K+)-2Cl- cotransporters, NKCC2 and NCC. NKCC2 and NCC are activated by a kinase cascade comprising with-no-lysine [K] kinases (WNKs) and two homologous Ste20-related kinases, SPAK and OSR1. Gain-of-function mutations within the WNK-SPAK/OSR1-NKCC2/NCC pathway lead to renal salt retention and hypertension, whereas loss-of-function mutations have been associated with salt-losing tubulopathies such as Bartter or Gitelman syndromes. A Bartter-like syndrome has been also described in patients carrying gain-of-function mutations in the CaSR gene. Recent work suggested that CaSR signals via the WNK-SPAK/OSR1 cascade to modulate salt reabsorption along the distal nephron. The review presented here summarizes the latest progress in understanding of functional interactions between CaSR and WNKs and their potential impact on the renal salt handling and blood pressure.
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22
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Bassi V, Fattoruso O. The Role of Fractional Excretion of Uric Acid in the Differential Diagnosis of Hypotonic Hyponatraemia in Patients with Diuretic Therapy. Cureus 2020; 12:e7762. [PMID: 32455079 PMCID: PMC7243088 DOI: 10.7759/cureus.7762] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Hyponatraemia is the most common electrolyte imbalance found in hospital population and worldwide thiazide and loop-diuretics are among the most widely used drugs. Syndrome of inappropriate antidiuresis diagnosis (SIAD) is complicated in the presence of diuretic therapy due to the misleading clinical assessment of the extracellular volume status, and in order to make SIAD diagnosis it is often necessary to withdraw diuretic therapy. Our study aimed to investigate the diagnostic role of these alternative markers of volume status, serum uric acid (sUA) and fractional excretion of uric acid (FEUA), in hyponatraemic patients treated with different diuretic drugs. Eighty-nine patients were enrolled with the diagnosis of SIAD, diuretic-induced hyponatremia (DIH, treated with furosemide and potassium canrenoate) or thiazide-induced hyponatremia (TIH, treated with hydrochlorothiazide, metolazone or indapamide) and investigated with receiver operating characteristic analysis and a sensitivity test. Our results show that FEUA discriminated better than sUA between SIAD and DIH patients (area under curve 0.96, <0.001 vs. 0.88, <0.001) while it was a poor marker to discriminate between SIAD and TIH (0.65, NS vs. 0.67, NS). In conclusions, FEUA is an excellent marker to discriminate SIAD vs. sodium depleted patients treated with furosemide and/or potassium canrenoate while the diuretic withdrawal, beyond obtaining a serum Na normalization, is still mandatory for differential diagnosis of sodium depleted patients affected by thiazide-induced hyponatraemia.
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Affiliation(s)
- Vincenzo Bassi
- Internal Medicine, San Giovanni Bosco Hospital, ASL Napoli 1 Centro, Naples, ITA
| | - Olimpia Fattoruso
- Pathology, San Giovanni Bosco Hospital, ASL Napoli 1 Centro, Naples, ITA
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23
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Rao VS, Turner JM, Griffin M, Mahoney D, Asher J, Jeon S, Yoo PS, Boutagy N, Feher A, Sinusas A, Wilson FP, Finkelstein F, Testani JM. First-in-Human Experience With Peritoneal Direct Sodium Removal Using a Zero-Sodium Solution: A New Candidate Therapy for Volume Overload. Circulation 2020; 141:1043-1053. [PMID: 31910658 DOI: 10.1161/circulationaha.119.043062] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Loop diuretics have well-described toxicities, and loss of response to these agents is common. Alternative strategies are needed for the maintenance of euvolemia in heart failure (HF). Nonrenal removal of sodium directly across the peritoneal membrane (direct sodium removal [DSR]) with a sodium-free osmotic solution should result in extraction of large quantities of sodium with limited off-target solute removal. METHODS This article describes the preclinical development and first-in-human proof of concept for DSR. Sodium-free 10% dextrose was used as the DSR solution. Porcine experiments were conducted to investigate the optimal dwell time, safety, and scalability and to determine the effect of experimental heart failure. In the human study, participants with end-stage renal disease on peritoneal dialysis (PD) underwent randomization and crossover to either a 2-hour dwell with 1 L DSR solution or standard PD solution (Dianeal 4.25% dextrose, Baxter). The primary end point was completion of the 2-hour dwell without significant discomfort or adverse events, and the secondary end point was difference in sodium removal between DSR and standard PD solution. RESULTS Porcine experiments revealed that 1 L DSR solution removed 4.1±0.4 g sodium in 2 hours with negligible off-target solute removal and overall stable serum electrolytes. Increasing the volume of DSR solution cycled across the peritoneum increased sodium removal and substantially decreased plasma volume (P=0.005). In the setting of experimental heart failure with elevated right atrial pressure, sodium removal was ≈4 times greater than in healthy animals (P<0.001). In the human proof-of-concept study, DSR solution was well tolerated and not associated with significant discomfort or adverse events. Plasma electrolyte concentrations were stable, and off-target solute removal was negligible. Sodium removal was substantially higher with DSR (4.5±0.4 g) compared with standard PD solution (1.0±0.3 g; P<0.0001). CONCLUSIONS DSR was well tolerated in both animals and human subjects and produced substantially greater sodium removal than standard PD solution. Additional research evaluating the use of DSR as a method to prevent and treat hypervolemia in heart failure is warranted. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03801226.
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Affiliation(s)
- Veena S Rao
- Department of Internal Medicine, Section of Cardiovascular Medicine (V.S.R., M.G., D.M., N.B., J.M. Testani), Yale University School of Medicine, New Haven, CT
| | - Jeffrey M Turner
- Department of Medicine, Division of Nephrology (J.M. Turner, F.F.), Yale University School of Medicine, New Haven, CT
| | - Matthew Griffin
- Department of Internal Medicine, Section of Cardiovascular Medicine (V.S.R., M.G., D.M., N.B., J.M. Testani), Yale University School of Medicine, New Haven, CT
| | - Devin Mahoney
- Department of Internal Medicine, Section of Cardiovascular Medicine (V.S.R., M.G., D.M., N.B., J.M. Testani), Yale University School of Medicine, New Haven, CT
| | - Jennifer Asher
- Department of Comparative Medicine (J.A.), Yale University School of Medicine, New Haven, CT
| | | | - Peter S Yoo
- Department of Surgery, Transplantation and Immunology (P.S.Y.), Yale University School of Medicine, New Haven, CT
| | - Nabil Boutagy
- Department of Internal Medicine, Section of Cardiovascular Medicine (V.S.R., M.G., D.M., N.B., J.M. Testani), Yale University School of Medicine, New Haven, CT
| | - Attila Feher
- Department of Internal Medicine (A.F.), Yale University School of Medicine, New Haven, CT
| | - Albert Sinusas
- Department of Medicine, Yale Translational Research Imaging Center, Section of Cardiovascular Medicine (A.S.), Yale University School of Medicine, New Haven, CT
| | - F Perry Wilson
- Program of Applied Translational Research (F.P.W.), Yale University School of Medicine, New Haven, CT
| | - Fredric Finkelstein
- Department of Medicine, Division of Nephrology (J.M. Turner, F.F.), Yale University School of Medicine, New Haven, CT
| | - Jeffrey M Testani
- Department of Internal Medicine, Section of Cardiovascular Medicine (V.S.R., M.G., D.M., N.B., J.M. Testani), Yale University School of Medicine, New Haven, CT
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Peng C, Yu M, Zheng J. In Situ Ligand-Directed Growth of Gold Nanoparticles in Biological Tissues. NANO LETTERS 2020; 20:1378-1382. [PMID: 31880943 PMCID: PMC8667869 DOI: 10.1021/acs.nanolett.9b04911] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Fundamental understandings and precise control of nanoparticle growth in the complex biological environment are crucial to broadening their potential applications in tissue imaging. Herein, we report that glutathione (GSH), a widely used capping ligand for precise control of the size of gold nanoparticle (AuNP) down to single-atom level in test tubes, can also be used to direct the selective growth of the AuNPs in the mitochondria of renal tubule cells as well as hippocampus cells in the tissues. Precise control of this growth process can lead to the formation of both ultrasmall AuNPs with near-infrared luminescence and large plasmonic AuNPs. The observed selective growth of the AuNPs is likely due to unique GSH storage function of the mitochondria. Using a different ligand, β-glucose thiol, we also found that the brush border of the intestine for glucose absorption became the major site for the growth of luminescent AuNPs. These findings suggest that selective growth of AuNPs in the biological tissues can indeed be directed with specific ligands, opening up a new avenue to tissue labeling and future development of artificial bionano hybrid systems.
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Affiliation(s)
- Chuanqi Peng
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 W. Campbell Road, Richardson, Texas 75080, United States
| | - Mengxiao Yu
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 W. Campbell Road, Richardson, Texas 75080, United States
| | - Jie Zheng
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, 800 W. Campbell Road, Richardson, Texas 75080, United States
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25
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Mutig K, Bachmann S. Hyperkalemia and blood pressure regulation. Nephrol Dial Transplant 2019; 34:iii26-iii35. [PMID: 31800077 DOI: 10.1093/ndt/gfz218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Indexed: 11/12/2022] Open
Abstract
Hypertension is common in the general population. Management of hypertensive patients at risk of hyperkalemia is challenging due to potential life-threatening complications such as cardiac arrest. Chronic hyperkalemia is often associated with impaired renal ability to excrete excessive potassium ions (K+). This may refer to chronic kidney disease or certain pharmacological interventions, including broadly used renin-angiotensin-aldosterone system and calcineurin inhibitors. Understanding the intrinsic mechanisms permitting kidney adaptations to hyperkalemia is critical for choosing therapeutic strategies. Valuable insights were obtained from the analysis of familial hyperkalemic hypertension (FHHt) syndrome, which became a classic model for coincidence of high blood pressure and hyperkalemia. FHHt can be caused by mutations in several genes, all of them resulting in excessive activity of with-no-lysine kinases (WNKs) in the distal nephron of the kidney. WNKs have been increasingly recognized as key signalling enzymes in the regulation of renal sodium ions (Na+) and K+ handling, enabling adaptive responses to systemic shifts of potassium homoeostasis consequent to variations in dietary potassium intake or disease. The WNK signalling pathway recruits a complex protein network mediating catalytic and non-catalytic effects of distinct WNK isoforms on relevant Na+- or K+-transporting proteins. In this review article, we summarize recent progress in understanding WNK signalling. An update of available models for renal adaptation to hyperkalemic conditions is presented. Consequences for blood pressure regulation are discussed. Pharmacological targeting of WNKs or their substrates offers promising options to manage hypertension while preventing hyperkalemia.
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Affiliation(s)
- Kerim Mutig
- Institute of Vegetative Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Department of Pharmacology, I.M. Sechenov First Moscow State Medical University of the Ministry of Healthcare of the Russian Federation (Sechenovskiy University), Moscow, Russia
| | - Sebastian Bachmann
- Institute of Vegetative Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Schnoz C, Carrel M, Loffing J. Loss of sodium chloride co-transporter impairs the outgrowth of the renal distal convoluted tubule during renal development. Nephrol Dial Transplant 2019; 35:411-432. [DOI: 10.1093/ndt/gfz172] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 07/12/2019] [Indexed: 12/15/2022] Open
Abstract
Abstract
Background
Loss-of-function mutations in the sodium chloride (NaCl) co-transporter (NCC) of the renal distal convoluted tubule (DCT) cause Gitelman syndrome with hypokalemic alkalosis, hypomagnesemia and hypocalciuria. Since Gitelman patients are usually diagnosed around adolescence, we tested the idea that a progressive regression of the DCT explains the late clinical onset of the syndrome.
Methods
NCC wild-type and knockout (ko) mice were studied at Days 1, 4 and 10 and 6 weeks after birth using blood plasma analysis and morphological and biochemical methods.
Results
Plasma aldosterone levels and renal renin messenger RNA expression were elevated in NCC ko mice during the first days of life. In contrast, plasma ion levels did not differ between genotypes at age 10 days, but a significant hypomagnesemia was observed in NCC ko mice at 6 weeks. Immunofluorescent detection of parvalbumin (an early DCT marker) revealed that the fractional cortical volume of the early DCT is similar for mice of both genotypes at Day 4, but is significantly lower at Day 10 and is almost zero at 6 weeks in NCC ko mice. The DCT atrophy correlates with a marked reduction in the abundance of the DCT-specific Mg2+ channel TRPM6 (transient receptor potential cation channel subfamily M member 6) and an increased proteolytic activation of the epithelial Na+ channel (ENaC).
Conclusion
After an initial outgrowth, DCT development lags behind in NCC ko mice. The impaired DCT development associates at Day 1 and Day 10 with elevated renal renin and plasma aldosterone levels and activation of ENaC, respectively, suggesting that Gitelman syndrome might be present much earlier in life than is usually expected. Despite an early downregulation of TRPM6, hypomagnesemia is a rather late symptom.
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Affiliation(s)
| | - Monique Carrel
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Johannes Loffing
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
- National Centre of Competence in Research ‘Kidney.CH’, University of Zurich, Zurich, Switzerland
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27
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Wang J, Wang C, Xu N, Liu ZF, Pang DW, Zhang ZL. A virus-induced kidney disease model based on organ-on-a-chip: Pathogenesis exploration of virus-related renal dysfunctions. Biomaterials 2019; 219:119367. [PMID: 31344514 DOI: 10.1016/j.biomaterials.2019.119367] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 07/13/2019] [Accepted: 07/14/2019] [Indexed: 02/03/2023]
Abstract
Renal dysfunctions usually happen in viral infections and many viruses specially infect distal renal tubules, however the pathogenesis remains unknown. Here, in order to explore the pathogenesis of virus-related renal dysfunctions, a Pseudorabies Virus (PrV) induced kidney disease model was built on a distal tubule-on-a-chip (DTC), for the first time. The barrier structure and Na reabsorption of distal renal tubules were successfully reconstituted in DTCs. After PrV infection, results showed electrolyte regulation dysfunction in Na reabsorption for the disordered Na transporters, the broken reabsorption barrier, and the transformed microvilli. And it would lead to virus induced serum electrolyte abnormalities. This work brought us a new cognition about the advantages of organ-on-a-chip (OOC) in virus research, for it had given us a better insight into the pathogenesis of virus induced dysfunctions, based on its unique ability in function reproduction.
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Affiliation(s)
- Ji Wang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, and State Key Laboratory of Virology, Wuhan University, Wuhan 430072, PR China
| | - Cheng Wang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, and State Key Laboratory of Virology, Wuhan University, Wuhan 430072, PR China
| | - Na Xu
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, and State Key Laboratory of Virology, Wuhan University, Wuhan 430072, PR China
| | - Zheng-Fei Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China.
| | - Dai-Wen Pang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, and State Key Laboratory of Virology, Wuhan University, Wuhan 430072, PR China
| | - Zhi-Ling Zhang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, and State Key Laboratory of Virology, Wuhan University, Wuhan 430072, PR China.
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28
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Singh N, Avigan ZM, Kliegel JA, Shuch BM, Montgomery RR, Moeckel GW, Cantley LG. Development of a 2-dimensional atlas of the human kidney with imaging mass cytometry. JCI Insight 2019; 4:129477. [PMID: 31217358 DOI: 10.1172/jci.insight.129477] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 05/10/2019] [Indexed: 12/19/2022] Open
Abstract
An incomplete understanding of the biology of the human kidney, including the relative abundances of and interactions between intrinsic and immune cells, has long constrained the development of therapies for kidney disease. The small amount of tissue obtained by renal biopsy has previously limited the ability to use patient samples for discovery purposes. Imaging mass cytometry (IMC) is an ideal technology for quantitative interrogation of scarce samples, permitting concurrent analysis of more than 40 markers on a single tissue section. Using a validated panel of metal-conjugated antibodies designed to confer unique signatures on the structural and infiltrating cells comprising the human kidney, we performed simultaneous multiplexed imaging with IMC in 23 channels on 16 histopathologically normal human samples. We devised a machine-learning pipeline (Kidney-MAPPS) to perform single-cell segmentation, phenotyping, and quantification, thus creating a spatially preserved quantitative atlas of the normal human kidney. These data define selected baseline renal cell types, respective numbers, organization, and variability. We demonstrate the utility of IMC coupled to Kidney-MAPPS to qualitatively and quantitatively distinguish individual cell types and reveal expected as well as potentially novel abnormalities in diseased versus normal tissue. Our studies define a critical baseline data set for future quantitative analysis of human kidney disease.
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Affiliation(s)
- Nikhil Singh
- Section of Nephrology, Department of Internal Medicine
| | | | | | | | | | - Gilbert W Moeckel
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
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29
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Wu F, Lin Y, Liu Q. The emerging role of aldosterone/mineralocorticoid receptors in the pathogenesis of erectile dysfunction. Endocrine 2018; 61:372-382. [PMID: 29721801 DOI: 10.1007/s12020-018-1610-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 04/17/2018] [Indexed: 12/26/2022]
Abstract
PURPOSE Aldosterone is an old hormone that has been discovered for more than fifty years. The clinical application of its receptors' inhibitors, especially spirolactone, has benifited patients for decades worldwide. In this review, we briefly summarized the molecular mechanism of aldosterone/mineralocorticoid receptors (Ald-MRs) signaling in cardiovascular diseases and its emerging role in erectile dysfunction. METHODS We searched PubMed, Web of Science, and Scopus for manuscripts published prior to December 2017 using key words " aldosterone " AND " erectile dysfunction " OR " cardiovascular disease " OR " mineralocorticoid receptors ". Related literature and clinical perspectives were collated, summarized and discussed in this review. RESULTS The increase of reactive oxygen species production, inhibition of endothelial nitric oxide synthase system, and induction of inflammation are ubiquitous in vascular endothelial cells or vascular smooth muscle cells after the activation of Ald-MRs pathway. In addition, in cardiovascular diseases with over-active Ald-MRs signaling, MRs blockade could reverse the injury and improve the prognosis. Notably, multiple studies have correlated aldosterone and MRs to the pathogenesis of erectile function, while the mechanism is largely unperfectly identified. CONCLUSION In conclusion, we summarize the current evidence to highlight the potential role of aldosterone in erectile dysfunction and provide critical insights into the treatment of the disease.
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Affiliation(s)
- Fei Wu
- Department of Urology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, China.
| | - Yun Lin
- Department of Urology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, China
| | - Qingyong Liu
- Department of Urology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, 250014, China.
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30
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Wang YF, Lafont AG, Lee YC, Hwang PP. A novel function of calcitonin gene-related peptide in body fluid Cl- homeostasis. Proc Biol Sci 2017; 283:rspb.2016.0684. [PMID: 27306053 DOI: 10.1098/rspb.2016.0684] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/18/2016] [Indexed: 12/15/2022] Open
Abstract
Vertebrates need to maintain extracellular chloride (Cl(-)) concentrations to ensure the normal operation of physiological processes; the transition from aquatic to terrestrial environments necessitated the development of sophisticated mechanisms to ensure Cl(-) homeostasis in the face of fluctuating Cl(-) levels. Zebrafish calcitonin gene-related peptide (CGRP), unlike its splice variant calcitonin, does not respond to environmental Ca(2+) levels. This study aimed to test the hypothesis that CGRP is involved in the control of body fluid Cl(-) homeostasis. Acclimation to high-Cl(-) artificial water stimulated the mRNA expression of cgrp and the receptor (crlr1) when compared with low-Cl(-) CGRP knockdown induced upregulation of the Na(+)-Cl(-) co-transporter (ncc2b), while overexpression of CGRP resulted in the downregulation of ncc2b mRNA synthesis and a simultaneous decrease in Cl(-) uptake in embryos. Consistent with these findings, knockdown of either cgrp or crlr1 was found to increase the density of NCC2b-expressing cells in embryos. This is the first demonstration that CGRP acts as a hypochloremic hormone through suppressing NCC2b expression and the differentiation of NCC-expressing ionocytes. Elucidation of this novel function of CGRP in fish body fluid Cl(-) homeostasis promises to enhance our understanding of the related physiology in vertebrates.
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Affiliation(s)
- Yi-Fang Wang
- Institute of Fishery Science, National Taiwan University, Taipei, Taiwan Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Anne-Gaëlle Lafont
- Muséum National d'Histoire Naturelle, Sorbonne Universités, Research Unit BOREA, Biology of Aquatic Organisms and Ecosystems, CNRS 7208, IRD207, UPMC, UCBN, Paris, France
| | - Yi-Chun Lee
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Pung-Pung Hwang
- Institute of Fishery Science, National Taiwan University, Taipei, Taiwan Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
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31
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Poulsen SB, Christensen BM. Long-term aldosterone administration increases renal Na+-Cl− cotransporter abundance in late distal convoluted tubule. Am J Physiol Renal Physiol 2017; 313:F756-F766. [DOI: 10.1152/ajprenal.00352.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 10/04/2016] [Accepted: 10/07/2016] [Indexed: 11/22/2022] Open
Abstract
Renal Na+-Cl− cotransporter (NCC) is expressed in early distal convoluted tubule (DCT) 1 and late DCT (DCT2). NCC activity can be stimulated by aldosterone administration, and the mechanism is assumed to depend on the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which inactivates glucocorticoids that would otherwise occupy aldosterone receptors. Because 11β-HSD2 in rat may only be abundantly expressed in DCT2 cells and not in DCT1 cells, it has been speculated that aldosterone specifically stimulates NCC activity in DCT2 cells. In mice, however, it is debated if 11β-HSD2 is expressed in DCT2 cells. The present study examined whether aldosterone administration in mice stimulates NCC abundance and phosphorylation in DCT2 cells but not in DCT1 cells. B6/C57 male mice were administered 100 µg aldosterone·kg body weight−1·24 h−1 for 6 days and euthanized during isoflurane inhalation. Western blotting of whole kidney homogenate showed that aldosterone administration stimulated NCC and pT58-NCC abundances ( P < 0.001). In DCT1 cells, confocal microscopy detected no effect of the aldosterone administration on NCC and pT58-NCC abundances. By contrast, NCC and pT58-NCC abundances were stimulated by aldosterone administration in the middle of DCT2 ( P < 0.001 and <0.01, respectively) and at the junction between DCT2 and CNT ( P < 0.001 and <0.05, respectively). In contrast to rat, immunohistochemistry in mouse showed no/very weak 11β-HSD2 expression in DCT2 cells. Collectively, long-term aldosterone administration stimulates mouse NCC and pT58-NCC abundances in DCT2 cells and presumably not in DCT1 cells.
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32
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Filippatos TD, Rizos CV, Tzavella E, Elisaf MS. Gitelman syndrome: an analysis of the underlying pathophysiologic mechanisms of acid-base and electrolyte abnormalities. Int Urol Nephrol 2017; 50:91-96. [PMID: 28744758 DOI: 10.1007/s11255-017-1653-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/05/2017] [Indexed: 01/25/2023]
Abstract
Gitelman syndrome is the most common inherited tubular disease resulting from mutations of the SLC12A3 gene that encodes the thiazide-sensitive sodium-chloride cotransporter in the early distal convoluted tubules. The review presents the underlying pathophysiologic mechanisms of acid-base and electrolyte abnormalities observed in patients with Gitelman syndrome. The syndrome is usually characterized by hypokalemic metabolic alkalosis in combination with hypomagnesemia and hypocalciuria. Additionally, increased chloride excretion and renin/aldosterone levels, hypophosphatemia (occasionally), hyponatremia (rarely) and glucose intolerance/insulin resistance have been reported. The knowledge of the pathophysiologic mechanisms is useful for the treatment of patients with Gitelman syndrome as well as for the understanding of other tubular diseases.
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Affiliation(s)
- T D Filippatos
- Department of Internal Medicine, Medical School, University of Ioannina, 45110, Ioannina, Greece.
| | - C V Rizos
- Department of Internal Medicine, Medical School, University of Ioannina, 45110, Ioannina, Greece
| | - E Tzavella
- Department of Internal Medicine, Medical School, University of Ioannina, 45110, Ioannina, Greece
| | - M S Elisaf
- Department of Internal Medicine, Medical School, University of Ioannina, 45110, Ioannina, Greece
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Rao VS, Planavsky N, Hanberg JS, Ahmad T, Brisco-Bacik MA, Wilson FP, Jacoby D, Chen M, Tang WHW, Cherney DZI, Ellison DH, Testani JM. Compensatory Distal Reabsorption Drives Diuretic Resistance in Human Heart Failure. J Am Soc Nephrol 2017; 28:3414-3424. [PMID: 28739647 DOI: 10.1681/asn.2016111178] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 06/19/2017] [Indexed: 12/31/2022] Open
Abstract
Understanding the tubular location of diuretic resistance (DR) in heart failure (HF) is critical to developing targeted treatment strategies. Rodents chronically administered loop diuretics develop DR due to compensatory distal tubular sodium reabsorption, but whether this translates to human DR is unknown. We studied consecutive patients with HF (n=128) receiving treatment with loop diuretics at the Yale Transitional Care Center. We measured the fractional excretion of lithium (FELi), the gold standard for in vivo assessment of proximal tubular and loop of Henle sodium handling, to assess sodium exit after loop diuretic administration and FENa to assess the net sodium excreted into the urine. The mean±SD prediuretic FELi was 16.2%±9.5%, similar to that in a control cohort without HF not receiving diuretics (n=52; 16.6%±9.2%; P=0.82). Administration of a median of 160 (interquartile range, 40-270) mg intravenous furosemide equivalents increased FELi by 12.6%±10.8% (P<0.001) but increased FENa by only 4.8%±3.3%. Thus, only 34% (interquartile range, 15.6%-75.7%) of the estimated diuretic-induced sodium release did not undergo distal reabsorption. After controlling for urine diuretic levels, the increase in FELi explained only 6.4% of the increase in FENa (P=0.002). These data suggest that administration of high-dose loop diuretics to patients with HF yields meaningful increases in sodium exit from the proximal tubule/loop of Henle. However, little of this sodium seems to reach the urine, consistent with findings from animal models that indicate that distal tubular compensatory sodium reabsorption is a primary driver of DR.
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Affiliation(s)
| | - Noah Planavsky
- Department of Geology and Geophysics, Yale University, New Haven, Connecticut
| | | | | | - Meredith A Brisco-Bacik
- Department of Medicine, Cardiovascular Division, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Francis P Wilson
- Department of Internal Medicine and.,Program of Applied Translational Research, Yale University School of Medicine, New Haven, Connecticut
| | | | | | - W H Wilson Tang
- Section of Heart Failure and Cardiac Transplantation, Cleveland Clinic, Cleveland, Ohio
| | - David Z I Cherney
- Division of Nephrology, Department of Medicine, Toronto General Hospital and Toronto General Hospital Research Institute, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada; and
| | - David H Ellison
- Oregon Clinical and Translational Research Institute, Oregon Health and Science University, Portland, Oregon
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McCormick JA, Ellison DH. Nephron Remodeling Underlies Hyperkalemia in Familial Hyperkalemic Hypertension. J Am Soc Nephrol 2017; 28:2555-2557. [PMID: 28705920 DOI: 10.1681/asn.2017060660] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- James A McCormick
- Department of Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - David H Ellison
- Department of Medicine, Oregon Health and Science University, Portland, Oregon; and .,Renal Section, Veterans Admininstration Portland Health Care System, Portland, Oregon
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Alexander RT, Dimke H. Effect of diuretics on renal tubular transport of calcium and magnesium. Am J Physiol Renal Physiol 2017; 312:F998-F1015. [DOI: 10.1152/ajprenal.00032.2017] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 02/22/2017] [Accepted: 02/27/2017] [Indexed: 01/07/2023] Open
Abstract
Calcium (Ca2+) and Magnesium (Mg2+) reabsorption along the renal tubule is dependent on distinct trans- and paracellular pathways. Our understanding of the molecular machinery involved is increasing. Ca2+ and Mg2+ reclamation in kidney is dependent on a diverse array of proteins, which are important for both forming divalent cation-permeable pores and channels, but also for generating the necessary driving forces for Ca2+ and Mg2+ transport. Alterations in these molecular constituents can have profound effects on tubular Ca2+ and Mg2+ handling. Diuretics are used to treat a large range of clinical conditions, but most commonly for the management of blood pressure and fluid balance. The pharmacological targets of diuretics generally directly facilitate sodium (Na+) transport, but also indirectly affect renal Ca2+ and Mg2+ handling, i.e., by establishing a prerequisite electrochemical gradient. It is therefore not surprising that substantial alterations in divalent cation handling can be observed following diuretic treatment. The effects of diuretics on renal Ca2+ and Mg2+ handling are reviewed in the context of the present understanding of basal molecular mechanisms of Ca2+ and Mg2+ transport. Acetazolamide, osmotic diuretics, Na+/H+ exchanger (NHE3) inhibitors, and antidiabetic Na+/glucose cotransporter type 2 (SGLT) blocking compounds, target the proximal tubule, where paracellular Ca2+ transport predominates. Loop diuretics and renal outer medullary K+ (ROMK) inhibitors block thick ascending limb transport, a segment with significant paracellular Ca2+ and Mg2+ transport. Thiazides target the distal convoluted tubule; however, their effect on divalent cation transport is not limited to that segment. Finally, potassium-sparing diuretics, which inhibit electrogenic Na+ transport at distal sites, can also affect divalent cation transport.
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Affiliation(s)
- R. Todd Alexander
- Membrane Protein Disease Research Group, Department of Physiology, University of Alberta, Edmonton, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Canada; and
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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McDonough AA, Youn JH. Potassium Homeostasis: The Knowns, the Unknowns, and the Health Benefits. Physiology (Bethesda) 2017; 32:100-111. [PMID: 28202621 PMCID: PMC5337831 DOI: 10.1152/physiol.00022.2016] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Potassium homeostasis has a very high priority because of its importance for membrane potential. Although extracellular K+ is only 2% of total body K+, our physiology was evolutionarily tuned for a high-K+, low-Na+ diet. We review how multiple systems interface to accomplish fine K+ balance and the consequences for health and disease.
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Affiliation(s)
- Alicia A McDonough
- Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, California; and
| | - Jang H Youn
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California
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37
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Flood P, Alvarez L, Reynaud EG. Free-floating epithelial micro-tissue arrays: a low cost and versatile technique. Biofabrication 2016; 8:045006. [DOI: 10.1088/1758-5090/8/4/045006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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38
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Hughes AD. How do thiazide and thiazide-like diuretics lower blood pressure? J Renin Angiotensin Aldosterone Syst 2016; 5:155-60. [PMID: 15803433 DOI: 10.3317/jraas.2004.034] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Thiazide diuretics are widely used for the treatment of hypertension, but the mechanism by which these drugs lower blood pressure in the long term remains unknown. This article reviews current knowledge about the hypotensive actions of thiazides and thiazide-like diuretics and discusses possible mechanisms of action.
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Affiliation(s)
- Alun D Hughes
- Clinical Pharmacology, Faculty of Medicine, Imperial College London, London W21NY, UK.
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39
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Nagami GT. Hyperchloremia – Why and how. Nefrologia 2016; 36:347-53. [DOI: 10.1016/j.nefro.2016.04.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 04/11/2016] [Indexed: 01/17/2023] Open
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40
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Abdelhadi O, Iancu D, Stanescu H, Kleta R, Bockenhauer D. EAST syndrome: Clinical, pathophysiological, and genetic aspects of mutations in KCNJ10. Rare Dis 2016; 4:e1195043. [PMID: 27500072 PMCID: PMC4961265 DOI: 10.1080/21675511.2016.1195043] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 05/02/2016] [Accepted: 05/24/2016] [Indexed: 11/04/2022] Open
Abstract
EAST syndrome is a recently described autosomal recessive disorder secondary to mutations in KCNJ10 (Kir4.1), a gene encoding a potassium channel expressed in the brain, eye, ear and kidney. This condition is characterized by 4 cardinal features; Epilepsy, Ataxia, Sensorineural deafness, and (a renal salt-wasting) Tubulopathy, hence the acronym EAST syndrome. Here we review reported clinical manifestations, in particular the neurological signs and symptoms which typically have the most impact on the quality of life of patients. In addition we review the pathophysiology and genetic aspects of the disease. So far 14 different KCNJ10 mutations have been published which either directly affect channel function or may lead to mislocalisation. Investigations of the pathophysiology may provide clues to potential treatments.
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Affiliation(s)
- Ola Abdelhadi
- Center for Nephrology, University College London, London, UK
| | - Daniela Iancu
- Center for Nephrology, University College London, London, UK
| | - Horia Stanescu
- Center for Nephrology, University College London, London, UK
| | - Robert Kleta
- Center for Nephrology, University College London, London, UK
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41
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Emma F, Montini G, Parikh SM, Salviati L. Mitochondrial dysfunction in inherited renal disease and acute kidney injury. Nat Rev Nephrol 2016; 12:267-80. [PMID: 26804019 PMCID: PMC5469549 DOI: 10.1038/nrneph.2015.214] [Citation(s) in RCA: 224] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mitochondria are increasingly recognized as key players in genetic and acquired renal diseases. Most mitochondrial cytopathies that cause renal symptoms are characterized by tubular defects, but glomerular, tubulointerstitial and cystic diseases have also been described. For example, defects in coenzyme Q10 (CoQ10) biosynthesis and the mitochondrial DNA 3243 A>G mutation are important causes of focal segmental glomerulosclerosis in children and in adults, respectively. Although they sometimes present with isolated renal findings, mitochondrial diseases are frequently associated with symptoms related to central nervous system and neuromuscular involvement. They can result from mutations in nuclear genes that are inherited according to classic Mendelian rules or from mutations in mitochondrial DNA, which are transmitted according to more complex rules of mitochondrial genetics. Diagnosis of mitochondrial disorders involves clinical characterization of patients in combination with biochemical and genetic analyses. In particular, prompt diagnosis of CoQ10 biosynthesis defects is imperative because of their potentially reversible nature. In acute kidney injury (AKI), mitochondrial dysfunction contributes to the physiopathology of tissue injury, whereas mitochondrial biogenesis has an important role in the recovery of renal function. Potential therapies that target mitochondrial dysfunction or promote mitochondrial regeneration are being developed to limit renal damage during AKI and promote repair of injured tissue.
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Affiliation(s)
- Francesco Emma
- Division of Nephrology and Dialysis, Ospedale Pediatrico Bambino Gesù-IRCCS, Piazza Sant'Onofrio 4, 00165 Rome, Italy
| | - Giovanni Montini
- Pediatric Nephrology and Dialysis Unit, Department of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Via della Commenda 9, Milano, Italy
| | - Samir M Parikh
- Division of Nephrology and Center for Vascular Biology Research, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, Massachusetts 02215, USA
| | - Leonardo Salviati
- Clinical Genetics Unit, Department of Woman and Child Health, University of Padova, Via Giustiniani 3, 35128, Padova, Italy
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Takabe S, Inokuchi M, Yamaguchi Y, Hyodo S. Distribution and dynamics of branchial ionocytes in houndshark reared in full-strength and diluted seawater environments. Comp Biochem Physiol A Mol Integr Physiol 2016; 198:22-32. [PMID: 27040185 DOI: 10.1016/j.cbpa.2016.03.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/18/2016] [Accepted: 03/23/2016] [Indexed: 12/22/2022]
Abstract
In teleost fishes, it is well-established that the gill serves as an important ionoregulatory organ in addition to its primary function of respiratory gas exchange. In elasmobranchs, however, the ionoregulatory function of the gills is still incompletely understood. Although two types of ionocytes, Na(+)/K(+)-ATPase (NKA)-rich (type-A) cell and vacuolar-type H(+)-ATPase (V-ATPase)-rich (type-B) cell, have been found in elasmobranch fishes, these cells were considered to function primarily in acid-base regulation. In the present study, we examined ion-transporting proteins expressed in ionocytes of Japanese-banded houndshark, Triakis scyllium, reared in full-strength seawater (SW) and transferred to diluted (30%) SW. In addition to the upregulation of NKA and Na(+)/H(+) exchanger type 3 (NHE3) mRNAs in the type-A ionocytes, we found that Na(+), Cl(-) cotransporter (NCC, Slc12a3) is expressed in a subpopulation of the type-B ionocytes, and that the expression level of NCC mRNA was enhanced in houndsharks transferred to a low-salinity environment. These results suggest that elasmobranch gill ionocytes contribute to NaCl uptake in addition to the already described function of acid-base regulation, and that NCC is most probably one of the key molecules for hyper-osmoregulatory function of elasmobranch gills. The existence of two types of ionocytes (NHE3- and NCC-expressing cells) that are responsible for NaCl absorption seems to be a common feature in both teleosts and elasmobranchs for adaptation to a low salinity environment. A possible driving mechanism for NCC in type-B ionocytes is discussed.
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Affiliation(s)
- Souichirou Takabe
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan.
| | - Mayu Inokuchi
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan
| | - Yoko Yamaguchi
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan; Hawai'i Institute of Marine Biology, University of Hawai'i, 46-007 Lilipuna Road, Kaneohe, HI 96744, USA
| | - Susumu Hyodo
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan
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43
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Czogalla J, Vohra T, Penton D, Kirschmann M, Craigie E, Loffing J. The mineralocorticoid receptor (MR) regulates ENaC but not NCC in mice with random MR deletion. Pflugers Arch 2016; 468:849-58. [PMID: 26898302 DOI: 10.1007/s00424-016-1798-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/03/2016] [Accepted: 02/08/2016] [Indexed: 12/13/2022]
Abstract
Aldosterone binds to the mineralocorticoid receptor (MR) and increases renal Na(+) reabsorption via up-regulation of the epithelial Na(+) channel (ENaC) and the Na(+)-K(+)-ATPase in the collecting system (CS) and possibly also via the NaCl cotransporter (NCC) in the distal convoluted tubule (DCT). However, whether aldosterone directly regulates NCC via MR or indirectly through systemic alterations remains controversial. We used mice with deletion of MR in ∼20 % of renal tubule cells (MR/X mice), in which MR-positive (MR(wt)) and -negative (MR(ko)) cells can be studied side-by-side in the same physiological context. Adult MR/X mice showed similar mRNA and protein levels of renal ion transport proteins to control mice. In MR/X mice, no differences in NCC abundance and phosphorylation was seen between MR(wt) and MR(ko) cells and dietary Na(+) restriction up-regulated NCC to similar extent in both groups of cells. In contrast, MR(ko) cells in the CS did not show any detectable alpha-ENaC abundance or apical targeting of ENaC neither on control diet nor in response to dietary Na(+) restriction. Furthermore, Na(+)-K(+)-ATPase expression was unaffected in MR(ko) cells of the DCT, while it was lost in MR(ko) cells of the CS. In conclusion, MR is crucial for ENaC and Na(+)-K(+)-ATPase regulation in the CS, but is dispensable for NCC and Na(+)-K(+)-ATPase regulation in the DCT.
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Affiliation(s)
- Jan Czogalla
- Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.,Swiss National Centre for Competence in Research "Kidney Control of Homeostasis", Zurich, Switzerland
| | - Twinkle Vohra
- Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - David Penton
- Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.,Swiss National Centre for Competence in Research "Kidney Control of Homeostasis", Zurich, Switzerland
| | - Moritz Kirschmann
- Center for Microscopy and Image Analysis, University of Zurich, Zurich, Switzerland
| | - Eilidh Craigie
- Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.,Swiss National Centre for Competence in Research "Kidney Control of Homeostasis", Zurich, Switzerland
| | - Johannes Loffing
- Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland. .,Swiss National Centre for Competence in Research "Kidney Control of Homeostasis", Zurich, Switzerland.
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44
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Lin CH, Hu HJ, Hwang PP. Cortisol regulates sodium homeostasis by stimulating the transcription of sodium-chloride transporter (NCC) in zebrafish (Danio rerio). Mol Cell Endocrinol 2016; 422:93-102. [PMID: 26678829 DOI: 10.1016/j.mce.2015.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 11/16/2015] [Accepted: 12/01/2015] [Indexed: 12/28/2022]
Abstract
In mammals, sodium/hydrogen exchanger (NHE) and sodium-chloride cotransporter (NCC) are expressed in renal tubules, and exhibit functional redundancy and mutual compensation in Na(+) uptake. In teleosts, the gills of the adult and skin of the embryonic stage function as external kidneys, and ionocytes are responsible for ionoregulation in these tissues. NHE- and NCC-expressing ionocytes mutually cooperate to adjust Na(+) uptake, which is analogous to the activity of the mammalian kidney. Cortisol is a hormone that controls Na(+) uptake through regulating NCC expression and activity in mammals; however, cortisol-mediated control of NCC expression is little understood in non-mammalian vertebrates, such as teleosts. It is essential for our understanding of the evolution of such regulation to determine whether cortisol has a conserved effect on NCC in vertebrates. In the present study, we treated zebrafish embryos with low Na(+) medium (LNa, 0.04 mM Na(+)) for 3 d to stimulate the mRNA expression of nhe3b, ncc, and cyp11b1 (a cortisol-synthesis enzyme) and whole body cortisol level. Exogenous cortisol treatment (20 mg/l, 3 d) resulted in an elevation of whole-body Na(+) content, ncc expression, and the density of ncc-expressing cells in zebrafish larvae. In loss-of-function experiments, microinjection of glucocorticoid receptor (gr) morpholino (MO) suppressed sodium content, ncc expression, and the density of ncc-expressing cells, but injection of mr MO had no such effects. In addition, exogenous cortisol treatment and gr MO injection also altered ncc expression and the density of ncc-expressing cells in gcm2 morphant larvae. Taken together, cortisol and GR appear to regulate Na(+) absorption through stimulating ncc expression and the differentiation of ncc-expressing ionocytes, providing new insights into the actions of cortisol on Na(+) uptake.
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Affiliation(s)
- Chia-Hao Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan; National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Huei-Jyun Hu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan
| | - Pung-Pung Hwang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan.
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Abstract
The impaired capacity of the kidney to excrete sodium plays an essential role in the development of hypertension. Adrenal corticosteroids control renal handling of sodium by regulating tubular sodium reabsorption in the distal nephron where both mineralocorticoid receptors (MR) and glucocorticoid receptors are expressed. In addition, cell type- and segment-specific expression of 11β-HSD2 and sodium transporters such as Na-Cl cotransporter (NCC), epithelial sodium channel (ENaC), and pendrin/Na(+)-driven Cl(-)/HCO3 (-) exchanger (NDCBE) builds a distinctive model of sodium transport in the aldosterone-sensitive distal nephron. Aberrant MR activation in the distal nephron triggers salt-sensitive hypertension and hypokalemia through inappropriate sodium reabsorption and potassium secretion. However, MR activity is not necessarily modulated by the ligand alone. Recently, several lines of evidence revealed alternative mechanisms that regulate the activity of MR in a ligand-independent manner or through ligand binding modulation. This review summarizes the disorders related to MR activation in individual tubular cells and highlights the renal mechanism of salt-sensitive hypertension and new approaches for the prevention and treatment of this disease.
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Affiliation(s)
- Nobuhiro Ayuzawa
- Department of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan
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46
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Cornelius RJ, Wang B, Wang-France J, Sansom SC. Maintaining K + balance on the low-Na +, high-K + diet. Am J Physiol Renal Physiol 2016; 310:F581-F595. [PMID: 26739887 DOI: 10.1152/ajprenal.00330.2015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 12/29/2015] [Indexed: 02/07/2023] Open
Abstract
A low-Na+, high-K+ diet (LNaHK) is considered a healthier alternative to the "Western" high-Na+ diet. Because the mechanism for K+ secretion involves Na+ reabsorptive exchange for secreted K+ in the distal nephron, it is not understood how K+ is eliminated with such low Na+ intake. Animals on a LNaHK diet produce an alkaline load, high urinary flows, and markedly elevated plasma ANG II and aldosterone levels to maintain their K+ balance. Recent studies have revealed a potential mechanism involving the actions of alkalosis, urinary flow, elevated ANG II, and aldosterone on two types of K+ channels, renal outer medullary K+ and large-conductance K+ channels, located in principal and intercalated cells. Here, we review these recent advances.
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Affiliation(s)
- Ryan J Cornelius
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon; and
| | - Bangchen Wang
- Department of Cellular/Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
| | - Jun Wang-France
- Department of Cellular/Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
| | - Steven C Sansom
- Department of Cellular/Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
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DiNicolantonio JJ, Bhutani J, Lavie CJ, O'Keefe JH. Evidence-based diuretics: focus on chlorthalidone and indapamide. Future Cardiol 2015; 11:203-17. [PMID: 25760879 DOI: 10.2217/fca.14.83] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Thiazide and thiazide-like diuretics are cornerstone treatments for hypertension. However, unlike chlorthalidone (CTD) and indapamide (IDP), hydrochlorothiazide (HCTZ) lacks evidence for reducing morbidity and mortality as monotherapy compared with placebo or control. Despite this fact, HCTZ is prescribed much more frequently than CTD or IDP. We believe that all hypertension guidelines should follow the National Institute for Health and Excellence (NICE) and make IDP and CTD first choice 'thiazide-like diuretics.' This article will focus on the available evidence pertaining to HCTZ versus CTD and IDP. We will review the pharmacological differences between these three diuretics, as well as the clinical trial data and important side effects.
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48
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Di Chiara M, Glaudemans B, Loffing-Cueni D, Odermatt A, Al-Hasani H, Devuyst O, Faresse N, Loffing J. Rab-GAP TBC1D4 (AS160) is dispensable for the renal control of sodium and water homeostasis but regulates GLUT4 in mouse kidney. Am J Physiol Renal Physiol 2015; 309:F779-90. [PMID: 26336159 DOI: 10.1152/ajprenal.00139.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 08/29/2015] [Indexed: 12/17/2022] Open
Abstract
The Rab GTPase-activating protein TBC1D4 (AS160) controls trafficking of the glucose transporter GLUT4 in adipocytes and skeletal muscle cells. TBC1D4 is also highly abundant in the renal distal tubule, although its role in this tubule is so far unknown. In vitro studies suggest that it is involved in the regulation of renal transporters and channels such as the epithelial sodium channel (ENaC), aquaporin-2 (AQP2), and the Na+-K+-ATPase. To assess the physiological role of TBC1D4 in the kidney, wild-type (TBC1D4+/+) and TBC1D4-deficient (TBC1D4-/-) mice were studied. Unexpectedly, neither under standard nor under challenging conditions (low Na+/high K+, water restriction) did TBC1D4-/- mice show any difference in urinary Na+ and K+ excretion, urine osmolarity, plasma ion and aldosterone levels, and blood pressure compared with TBC1D4+/+ mice. Also, immunoblotting did not reveal any change in the abundance of major renal sodium- and water-transporting proteins [Na-K-2Cl cotransporter (NKCC2) NKCC2, NaCl cotransporter (NCC), ENaC, AQP2, and the Na+-K+-ATPase]. However, the abundance of GLUT4, which colocalizes with TBC1D4 along the distal nephron of TBC1D4+/+ mice, was lower in whole kidney lysates of TBC1D4-/- mice than in TBC1D4+/+ mice. Likewise, primary thick ascending limb (TAL) cells isolated from TBC1D4-/- mice showed an increased basal glucose uptake and an abrogated insulin response compared with TAL cells from TBC1D4+/+ mice. Thus, TBC1D4 is dispensable for the regulation of renal Na+ and water transport, but may play a role for GLUT4-mediated basolateral glucose uptake in distal tubules. The latter may contribute to the known anaerobic glycolytic capacity of distal tubules during renal ischemia.
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Affiliation(s)
- Marianna Di Chiara
- Institute of Anatomy, University of Zurich, Zurich, Switzerland; Zurich Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Bob Glaudemans
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | | | - Alex Odermatt
- Division of Molecular and Systems Toxicology, Pharmacenter, University of Basel, Basel, Switzerland; National Center of Competence in Research "Kidney.CH," Switzerland; and
| | - Hadi Al-Hasani
- German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich-Heine-University and German Center for Diabetes Research, Düsseldorf, Germany
| | - Olivier Devuyst
- Zurich Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland; Institute of Physiology, University of Zurich, Zurich, Switzerland; National Center of Competence in Research "Kidney.CH," Switzerland; and
| | - Nourdine Faresse
- Institute of Anatomy, University of Zurich, Zurich, Switzerland; Zurich Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland; National Center of Competence in Research "Kidney.CH," Switzerland; and
| | - Johannes Loffing
- Institute of Anatomy, University of Zurich, Zurich, Switzerland; Zurich Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland; National Center of Competence in Research "Kidney.CH," Switzerland; and
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Wang YF, Yan JJ, Tseng YC, Chen RD, Hwang PP. Molecular Physiology of an Extra-renal Cl(-) Uptake Mechanism for Body Fluid Cl(-) Homeostasis. Int J Biol Sci 2015; 11:1190-203. [PMID: 26327813 PMCID: PMC4551755 DOI: 10.7150/ijbs.11737] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 07/25/2015] [Indexed: 01/07/2023] Open
Abstract
The development of an ion regulatory mechanism for body fluid homeostasis was an important trait for vertebrates during the evolution from aquatic to terrestrial life. The homeostatic mechanism of Cl- in aquatic fish appears to be similar to that of terrestrial vertebrates; however, the mechanism in non-mammalian vertebrates is poorly understood. Unlike in mammals, in which the kidney plays a central role, in most fish species, the gill is responsible for the maintenance of Cl- homeostasis via Cl- transport uptake mechanisms. Previous studies in zebrafish identified Na+-Cl- cotransporter (NCC) 2b-expressing cells in the gills and skin as the major ionocytes responsible for Cl- uptake, similar to distal convoluted tubular cells in mammalian kidney. However, the mechanism by which basolateral ions exit from NCC cells is still unclear. Of the in situ hybridization signals of twelve members of the clc Cl- channel family, only that of clc-2c exhibited an ionocyte pattern in the gill and embryonic skin. Double in situ hybridization/immunocytochemistry confirmed colocalization of apical NCC2b with basolateral CLC-2c. Acclimation to a low Cl- environment increased mRNA expression of both clc-2c and ncc2b, and also the protein expression of CLC-2c in embryos and adult gills. Loss-of-function of clc-2c resulted in a significant decrease in whole body Cl- content in zebrafish embryos, a phenotype similar to that of ncc2b mutants; this finding suggests a role for CLC-2c in Cl- uptake. Translational knockdown of clc-2c stimulated ncc2b mRNA expression and vice versa, revealing cooperation between these two transporters in the context of zebrafish Cl- homeostasis. Further comparative genomic and phylogenetic analyses revealed that zebrafish CLC-2c is a fish-specific isoform that diverged from a kidney-predominant homologue, in the same manner as NCC2b and its counterparts (NCCs). Several lines of molecular and cellular physiological evidences demonstrated the cofunctional role of apical NCC2b and basolateral CLC-2c in the gill/skin Cl- uptake pathway. Taking the phylogenetic evidence into consideration, fish-specific NCC2b and CLC-2c may have coevolved to perform extra-renal Cl- uptake during the evolution of vertebrates in an aquatic environment.
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Affiliation(s)
- Yi-Fang Wang
- 1. Institute of Fishery Science, National Taiwan University, Taipei city, Taiwan ; 2. Institute of Cellular and Organismic Biology, Academia Sinica, Taipei city, Taiwan
| | - Jia-Jiun Yan
- 2. Institute of Cellular and Organismic Biology, Academia Sinica, Taipei city, Taiwan
| | - Yung-Che Tseng
- 3. Department of Life Science, National Taiwan Normal University, Taipei city, Taiwan
| | - Ruo-Dong Chen
- 2. Institute of Cellular and Organismic Biology, Academia Sinica, Taipei city, Taiwan
| | - Pung-Pung Hwang
- 1. Institute of Fishery Science, National Taiwan University, Taipei city, Taiwan ; 2. Institute of Cellular and Organismic Biology, Academia Sinica, Taipei city, Taiwan
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Torres N, Guevara-Cruz M, Velázquez-Villegas LA, Tovar AR. Nutrition and Atherosclerosis. Arch Med Res 2015; 46:408-26. [DOI: 10.1016/j.arcmed.2015.05.010] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 05/12/2015] [Indexed: 12/15/2022]
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