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Abu Obaid A, Ivandic I, Korsching SI. Deciphering the function of the fifth class of Gα proteins: regulation of ionic homeostasis as unifying hypothesis. Cell Mol Life Sci 2024; 81:213. [PMID: 38727814 PMCID: PMC11087313 DOI: 10.1007/s00018-024-05228-w] [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: 02/26/2024] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 05/13/2024]
Abstract
Trimeric G proteins transduce signals from a superfamily of receptors and each G protein controls a wide range of cellular and systemic functions. Their highly conserved alpha subunits fall in five classes, four of which have been well investigated (Gs, Gi, G12, Gq). In contrast, the function of the fifth class, Gv is completely unknown, despite its broad occurrence and evolutionary ancient origin (older than metazoans). Here we show a dynamic presence of Gv mRNA in several organs during early development of zebrafish, including the hatching gland, the pronephros and several cartilage anlagen, employing in situ hybridisation. Next, we generated a Gv frameshift mutation in zebrafish and observed distinct phenotypes such as reduced oviposition, premature hatching and craniofacial abnormalities in bone and cartilage of larval zebrafish. These phenotypes could suggest a disturbance in ionic homeostasis as a common denominator. Indeed, we find reduced levels of calcium, magnesium and potassium in the larvae and changes in expression levels of the sodium potassium pump atp1a1a.5 and the sodium/calcium exchanger ncx1b in larvae and in the adult kidney, a major osmoregulatory organ. Additionally, expression of sodium chloride cotransporter slc12a3 and the anion exchanger slc26a4 is altered in complementary ways in adult kidney. It appears that Gv may modulate ionic homeostasis in zebrafish during development and in adults. Our results constitute the first insight into the function of the fifth class of G alpha proteins.
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Affiliation(s)
- Asmaa Abu Obaid
- Institute of Genetics, Faculty of Mathematics and Natural Sciences of the University at Cologne, Zülpicher Str. 47A, 50674, Cologne, Germany
- Department of Optometry, Faculty of Modern Sciences, The Arab American University, Yousef Asfour Street, Ramallah, Palestine
| | - Ivan Ivandic
- Institute of Genetics, Faculty of Mathematics and Natural Sciences of the University at Cologne, Zülpicher Str. 47A, 50674, Cologne, Germany
| | - Sigrun I Korsching
- Institute of Genetics, Faculty of Mathematics and Natural Sciences of the University at Cologne, Zülpicher Str. 47A, 50674, Cologne, Germany.
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Zonnefeld AG, Cui CY, Tsitsipatis D, Piao Y, Fan J, Mazan-Mamczarz K, Xue Y, Indig FE, De S, Gorospe M. Characterization of age-associated gene expression changes in mouse sweat glands. Aging (Albany NY) 2024; 16:6717-6730. [PMID: 38637019 PMCID: PMC11087089 DOI: 10.18632/aging.205776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 03/18/2024] [Indexed: 04/20/2024]
Abstract
Evaporation of sweat on the skin surface is the major mechanism for dissipating heat in humans. The secretory capacity of sweat glands (SWGs) declines during aging, leading to heat intolerance in the elderly, but the mechanisms responsible for this decline are poorly understood. We investigated the molecular changes accompanying SWG aging in mice, where sweat tests confirmed a significant reduction of active SWGs in old mice relative to young mice. We first identified SWG-enriched mRNAs by comparing the skin transcriptome of Eda mutant Tabby male mice, which lack SWGs, with that of wild-type control mice by RNA-sequencing analysis. This comparison revealed 171 mRNAs enriched in SWGs, including 47 mRNAs encoding 'core secretory' proteins such as transcription factors, ion channels, ion transporters, and trans-synaptic signaling proteins. Among these, 28 SWG-enriched mRNAs showed significantly altered abundance in the aged male footpad skin, and 11 of them, including Foxa1, Best2, Chrm3, and Foxc1 mRNAs, were found in the 'core secretory' category. Consistent with the changes in mRNA expression levels, immunohistology revealed that higher numbers of secretory cells from old SWGs express the transcription factor FOXC1, the protein product of Foxc1 mRNA. In sum, our study identified mRNAs enriched in SWGs, including those that encode core secretory proteins, and altered abundance of these mRNAs and proteins with aging in mouse SWGs.
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Affiliation(s)
- Alexandra G. Zonnefeld
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Chang-Yi Cui
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Dimitrios Tsitsipatis
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Yulan Piao
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Jinshui Fan
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Krystyna Mazan-Mamczarz
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Yutong Xue
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Fred E. Indig
- Confocal Imaging Core Facility, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Supriyo De
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Myriam Gorospe
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
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Xu Z, Wang Y, Feng Y, Yang M, Shi G, Xuan Z, Xu F. Characteristics of sodium and water retention in rats with nephrotic syndrome induced by puromycin aminonucleoside. BMC Nephrol 2023; 24:309. [PMID: 37880610 PMCID: PMC10599035 DOI: 10.1186/s12882-023-03367-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 10/14/2023] [Indexed: 10/27/2023] Open
Abstract
INTRODUCTION Nephrotic syndrome (NS) is characterized by renal sodium and water retention. The mechanisms are not fully elucidated. METHODS The NS rat model was established by single intraperitoneal injection of 100 mg/kg puromycin aminonucleoside (PAN). The plasma electrolyte level and urinary sodium excretion were monitored dynamically. The changes of some sodium transporters, including epithelial Na+ channel (ENaC), Na+/H+ exchanger 3 (NHE3), Na+-K+-2Cl- cotransporter 2 (NKCC2) and Na+-Cl- cotransporter (NCC) in renal cortex at different time points and the level of peripheral circulation factors were detected. RESULTS The urinary sodium excretion of the model group increased significantly on the first day, then decreased compared with the control group, and there was no significant difference between the model group and the control group on the 12th day. The changes of peripheral circulation factors were not obvious. Some sodium transporters in renal cortex increased in varying degrees, while NKCC2 decreased significantly compared with the control group. CONCLUSIONS The occurrence of NS edema may not be related to the angiotensin system. The decrease of urinary sodium excretion is independent of the development of albuminuria. During the 18 days of observation, it can be divided into three stages: sodium retention, sodium compensation, and simple water retention. The mechanism is related to the increased expression of α-ENaC, γ-ENaC, NHE3 and NCC in a certain period of time, the compensatory decrease of NKCC2 expression and the continuous increase of aquaporin 2 (AQP2) expression.
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Affiliation(s)
- Zaiping Xu
- School of Pharmacy, Anhui University of Chinese Medicine, Longzihu Road 350, Hefei, Anhui, 230012, China
| | - Yunlai Wang
- School of Pharmacy, Anhui University of Chinese Medicine, Longzihu Road 350, Hefei, Anhui, 230012, China.
- Anhui Province Key Laboratory of Chinese Medicinal Formula, Hefei, Anhui, China.
- Institute for Pharmacodynamics and Safety Evaluation of Chinese Medicine, Anhui Academy of Chinese Medicine, Hefei, Anhui, China.
| | - Ye Feng
- School of Pharmacy, Anhui University of Chinese Medicine, Longzihu Road 350, Hefei, Anhui, 230012, China
| | - Mo Yang
- Scientific Research and Technology Center, Anhui University of Chinese Medicine, Hefei, Anhui, China
| | - Gaoxiang Shi
- School of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, Anhui, China
| | - Zihua Xuan
- School of Pharmacy, Anhui University of Chinese Medicine, Longzihu Road 350, Hefei, Anhui, 230012, China
| | - Fan Xu
- School of Pharmacy, Anhui University of Chinese Medicine, Longzihu Road 350, Hefei, Anhui, 230012, China.
- Anhui Province Key Laboratory of Chinese Medicinal Formula, Hefei, Anhui, China.
- Institute for Pharmacodynamics and Safety Evaluation of Chinese Medicine, Anhui Academy of Chinese Medicine, Hefei, Anhui, China.
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Koirala A, Pourafshar N, Daneshmand A, Wilcox CS, Mannemuddhu SS, Arora N. Etiology and Management of Edema: A Review. ADVANCES IN KIDNEY DISEASE AND HEALTH 2023; 30:110-123. [PMID: 36868727 DOI: 10.1053/j.akdh.2022.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 04/18/2023]
Abstract
The development of peripheral edema can often pose a significant diagnostic and therapeutic challenge for practitioners due to its association with a wide variety of underlying disorders ranging in severity. Updates to the original Starling's principle have provided new mechanistic insights into edema formation. Additionally, contemporary data highlighting the role of hypochloremia in the development of diuretic resistance provide a possible new therapeutic target. This article reviews the pathophysiology of edema formation and discusses implications for treatment.
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Affiliation(s)
- Abbal Koirala
- Division of Nephrology, University of Washington, Seattle, WA
| | - Negiin Pourafshar
- Division of Nephrology, MedStar Georgetown University Hospital, Washington DC
| | - Arvin Daneshmand
- Division of Nephrology, MedStar Georgetown University Hospital, Washington DC
| | | | | | - Nayan Arora
- Division of Nephrology, University of Washington, Seattle, WA.
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Do C, Vasquez PC, Soleimani M. Metabolic Alkalosis Pathogenesis, Diagnosis, and Treatment: Core Curriculum 2022. Am J Kidney Dis 2022; 80:536-551. [PMID: 35525634 PMCID: PMC10947768 DOI: 10.1053/j.ajkd.2021.12.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 12/03/2021] [Indexed: 02/02/2023]
Abstract
Metabolic alkalosis is a widespread acid-base disturbance, especially in hospitalized patients. It is characterized by the primary elevation of serum bicarbonate and arterial pH, along with a compensatory increase in Pco2 consequent to adaptive hypoventilation. The pathogenesis of metabolic alkalosis involves either a loss of fixed acid or a net accumulation of bicarbonate within the extracellular fluid. The loss of acid may be via the gastrointestinal tract or the kidney, whereas the sources of excess alkali may be via oral or parenteral alkali intake. Severe metabolic alkalosis in critically ill patients-arterial blood pH of 7.55 or higher-is associated with significantly increased mortality rate. The kidney is equipped with sophisticated mechanisms to avert the generation or the persistence (maintenance) of metabolic alkalosis by enhancing bicarbonate excretion. These mechanisms include increased filtration as well as decreased absorption and enhanced secretion of bicarbonate by specialized transporters in specific nephron segments. Factors that interfere with these mechanisms will impair the ability of the kidney to eliminate excess bicarbonate, therefore promoting the generation or impairing the correction of metabolic alkalosis. These factors include volume contraction, low glomerular filtration rate, potassium deficiency, hypochloremia, aldosterone excess, and elevated arterial carbon dioxide. Major clinical states are associated with metabolic alkalosis, including vomiting, aldosterone or cortisol excess, licorice ingestion, chloruretic diuretics, excess calcium alkali ingestion, and genetic diseases such as Bartter syndrome, Gitelman syndrome, and cystic fibrosis. In this installment in the AJKD Core Curriculum in Nephrology, we will review the pathogenesis of metabolic alkalosis; appraise the precipitating events; and discuss clinical presentations, diagnoses, and treatments of metabolic alkalosis.
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Affiliation(s)
- Catherine Do
- Division of Nephrology, University of New Mexico, and Veterans Administration Medical Center, Albuquerque, New Mexico
| | - Pamela C Vasquez
- Division of Nephrology, University of New Mexico, and Veterans Administration Medical Center, Albuquerque, New Mexico
| | - Manoocher Soleimani
- Division of Nephrology, Department of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico.
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Matulevičius A, Bernardinelli E, Brownstein Z, Roesch S, Avraham KB, Dossena S. Molecular Features of SLC26A4 Common Variant p.L117F. J Clin Med 2022; 11:jcm11195549. [PMID: 36233414 PMCID: PMC9570580 DOI: 10.3390/jcm11195549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/16/2022] [Accepted: 09/19/2022] [Indexed: 11/16/2022] Open
Abstract
The SLC26A4 gene, which encodes the anion exchanger pendrin, is involved in determining syndromic (Pendred syndrome) and non-syndromic (DFNB4) autosomal recessive hearing loss. SLC26A4 c.349C>T, p.L117F is a relatively common allele in the Ashkenazi Jewish community, where its minor allele frequency is increased compared to other populations. Although segregation and allelic data support the pathogenicity of this variant, former functional tests showed characteristics that were indistinguishable from those of the wild-type protein. Here, we applied a triad of cell-based assays, i.e., measurement of the ion transport activity by a fluorometric method, determination of the subcellular localization by confocal microscopy, and assessment of protein expression levels, to conclusively assign or exclude the pathogenicity of SLC26A4 p.L117F. This protein variant showed a moderate, but significant, reduction in ion transport function, a partial retention in the endoplasmic reticulum, and a strong reduction in expression levels as a consequence of an accelerated degradation by the Ubiquitin Proteasome System, all supporting pathogenicity. The functional and molecular features of human pendrin p.L117F were recapitulated by the mouse ortholog, thus indicating that a mouse carrying this variant might represent a good model of Pendred syndrome/DFNB4.
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Affiliation(s)
- Arnoldas Matulevičius
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Emanuele Bernardinelli
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Zippora Brownstein
- Department of Human Molecular Genetics & Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sebastian Roesch
- Department of Otorhinolaryngology, Head and Neck Surgery, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Karen B. Avraham
- Department of Human Molecular Genetics & Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Correspondence: (K.B.A.); (S.D.); Tel.: +972-3-6407030 (K.B.A.); +43-662-2420-80560 (S.D.)
| | - Silvia Dossena
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, 5020 Salzburg, Austria
- Correspondence: (K.B.A.); (S.D.); Tel.: +972-3-6407030 (K.B.A.); +43-662-2420-80560 (S.D.)
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Lu YT, Wang L, Hou LL, Zheng PP, Xu Q, Deng DT. SLC26A4 mutation in Pendred syndrome with hypokalemia: A case report. Medicine (Baltimore) 2022; 101:e30253. [PMID: 36107570 PMCID: PMC9439793 DOI: 10.1097/md.0000000000030253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
RATIONALE Pendred syndrome is an autosomal recessive disorder characterized by sensorineural hearing loss, inner ear malformations, goiter, and abnormal organification of iodide. It is caused by mutations in SLC26A4 gene, which encodes pendrin (a transporter of chloride, bicarbonate, and iodide). Pendred syndrome is a common cause of syndromic deafness, but the metabolic abnormalities it causes are often overlooked. Here, we report the case of a patient diagnosed with Pendred syndrome with hypokalemia. PATIENT CONCERNS A 53-year-old deaf-mute woman was hospitalized due to severe limb asthenia. The emergency examination showed that her blood potassium level was 1.8 mmol/L. DIAGNOSES Through the genetic test, we found a mutation of SLC26A4 gene in NM_000441: c.2027T>A, p.L676Q, as well as the SLC26A4 exon 5-6 deletion. These genetic variations pointed to Pendred syndrome (an autosomal recessive disorder that mainly affects the inner ear, thyroid, and kidney) which is a common cause of syndromic deafness. INTERVENTIONS The patient was treated with potassium supplements and screened for the cause of hypokalemia. OUTCOMES The patient was discharged after her potassium levels rose to the normal range. LESSONS Patients with Pendred syndrome may also have certain metabolic abnormalities; thus, more attention should be paid to them during clinical diagnosis.
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Affiliation(s)
- Ya-Ting Lu
- Department of Endocrinology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
| | - Lin Wang
- Department of Endocrinology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
| | - Le-Le Hou
- Department of Endocrinology, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu Province, China
| | - Ping-Ping Zheng
- Department of Endocrinology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
| | - Qian Xu
- Department of Endocrinology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
| | - Da-Tong Deng
- Department of Endocrinology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
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Do C, Evans GJ, DeAguero J, Escobar GP, Lin HC, Wagner B. Dysnatremia in Gastrointestinal Disorders. Front Med (Lausanne) 2022; 9:892265. [PMID: 35646996 PMCID: PMC9136014 DOI: 10.3389/fmed.2022.892265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/22/2022] [Indexed: 01/19/2023] Open
Abstract
The primary solute of the milieu intérieur is sodium and accompanying anions. The solvent is water. The kidneys acutely regulate homeostasis in filtration, secretion, and resorption of electrolytes, non-electrolytes, and minerals while balancing water retention and clearance. The gastrointestinal absorptive and secretory functions enable food digestion and water absorption needed to sustain life. Gastrointestinal perturbations including vomiting and diarrhea can lead to significant volume and electrolyte losses, overwhelming the renal homeostatic compensatory mechanisms. Dysnatremia, potassium and acid-base disturbances can result from gastrointestinal pathophysiologic processes. Understanding the renal and gastrointestinal contributions to homeostatis are important for the clinical evaluation of perturbed volume disturbances.
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Affiliation(s)
- Catherine Do
- Division of Nephrology, Department of Medicine, Kidney Institute of New Mexico, University of New Mexico Health Science Center, Albuquerque, NM, United States,New Mexico Veterans Administration Health Care System, Albuquerque, NM, United States,University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Gretta J. Evans
- University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Joshua DeAguero
- Division of Nephrology, Department of Medicine, Kidney Institute of New Mexico, University of New Mexico Health Science Center, Albuquerque, NM, United States,University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - G. Patricia Escobar
- Division of Nephrology, Department of Medicine, Kidney Institute of New Mexico, University of New Mexico Health Science Center, Albuquerque, NM, United States,University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Henry C. Lin
- New Mexico Veterans Administration Health Care System, Albuquerque, NM, United States
| | - Brent Wagner
- Division of Nephrology, Department of Medicine, Kidney Institute of New Mexico, University of New Mexico Health Science Center, Albuquerque, NM, United States,New Mexico Veterans Administration Health Care System, Albuquerque, NM, United States,University of New Mexico Health Sciences Center, Albuquerque, NM, United States,*Correspondence: Brent Wagner
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Spoletini G, Fitch G, Gillgrass L, Etherington C, Clifton I, Peckham DG. Urinary bicarbonate and metabolic alkalosis during exacerbations in cystic fibrosis. ERJ Open Res 2022; 8:00669-2021. [PMID: 35539439 PMCID: PMC9081541 DOI: 10.1183/23120541.00669-2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 03/23/2022] [Indexed: 11/06/2022] Open
Abstract
Pseudo-Bartter syndrome (PBS) is characterised by hypokalaemic, hyponatraemic and hypochloraemic metabolic alkalosis in the absence of renal tubules pathology; it is a well-recognised complication of cystic fibrosis (CF), in the context of dehydration and acute illness [1–7]. The aetiology of increased serum bicarbonate and metabolic alkalosis in CF is complex and appears to be driven, at least in part, by renal tubular CFTR dysfunctionhttps://bit.ly/3NFPkUu
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10
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Cox ZL, Rao VS, Testani JM. Classic and Novel Mechanisms of Diuretic Resistance in Cardiorenal Syndrome. KIDNEY360 2022; 3:954-967. [PMID: 36128483 PMCID: PMC9438407 DOI: 10.34067/kid.0006372021] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 02/23/2022] [Indexed: 01/10/2023]
Abstract
Despite the incompletely understood multiple etiologies and underlying mechanisms, cardiorenal syndrome is characterized by decreased glomerular filtration and sodium avidity. The underlying level of renal sodium avidity is of primary importance in driving a congested heart failure phenotype and ultimately determining the response to diuretic therapy. Historically, mechanisms of kidney sodium avidity and resultant diuretic resistance were primarily extrapolated to cardiorenal syndrome from non-heart failure populations. Yet, the mechanisms appear to differ between these populations. Recent literature in acute decompensated heart failure has refuted several classically accepted diuretic resistance mechanisms and reshaped how we conceptualize diuretic resistance mechanisms in cardiorenal syndrome. Herein, we propose an anatomically based categorization of diuretic resistance mechanisms to establish the relative importance of specific transporters and translate findings toward therapeutic strategies. Within this categorical structure, we discuss classic and novel mechanisms of diuretic resistance.
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Affiliation(s)
- Zachary L. Cox
- Department of Pharmacy Practice, Lipscomb University College of Pharmacy, Nashville, Tennessee,Department of Pharmacy, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Veena S. Rao
- Division of Internal Medicine, Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Jeffrey M. Testani
- Division of Internal Medicine, Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, Connecticut
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11
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Inoue T, Hisamichi M, Ichikawa D, Shibagaki Y, Yazawa M. The Effect of Add-on Acetazolamide to Conventional Diuretics for Diuretic-resistant Edema Complicated with Hypercapnia: A Report of Two Cases. Intern Med 2022; 61:373-378. [PMID: 34373379 PMCID: PMC8866788 DOI: 10.2169/internalmedicine.7896-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We herein report two cases in which add-on acetazolamide to furosemide was effective for diuretic-resistant volume overload and hypercapnia. Case 1 was a woman in her 40s presenting with volume overload due to the nephrotic syndrome with diabetes mellitus. Case 2 was a man in his 60s with fluid overload and non-nephrotic proteinuria and sepsis. In both cases, although fluid overload was resistant to high-dose loop diuretics and complicated with hypercapnia due to pulmonary effusion, add-on acetazolamide administration resulted in symptom resolution. The additional effect of acetazolamide occurred regardless of the degree of proteinuria and kidney function.
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Affiliation(s)
- Tomohiko Inoue
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Japan
| | - Mikako Hisamichi
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Japan
- Division of Nephrology, Department of Internal Medicine, Tokyo Takanawa Hospital, Japan
| | - Daisuke Ichikawa
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Japan
| | - Yugo Shibagaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Japan
| | - Masahiko Yazawa
- Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, Japan
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12
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Breiderhoff T, Himmerkus N, Meoli L, Fromm A, Sewerin S, Kriuchkova N, Nagel O, Ladilov Y, Krug S, Quintanova C, Stumpp M, Garbe-Schönberg D, Westernströer U, Merkel C, Brinkhus M, Altmüller J, Schweiger M, Mueller D, Mutig K, Morawski M, Halbritter J, Milatz S, Bleich M, Günzel D. Claudin-10a Deficiency Shifts Proximal Tubular Cl - Permeability to Cation Selectivity via Claudin-2 Redistribution. J Am Soc Nephrol 2022; 33:699-717. [PMID: 35031570 PMCID: PMC8970455 DOI: 10.1681/asn.2021030286] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 12/20/2021] [Indexed: 11/03/2022] Open
Abstract
Background The tight junction proteins claudin-2 and claudin-10a form paracellular cation and anion channels, respectively, and are expressed in the proximal tubule. However, the physiological role of claudin-10a in the kidney has been unclear. Methods To investigate the physiologic role of claudin-10a, we generated claudin-10a-deficient mice; confirmed successful knockout by Southern blot, Western blot, and immunofluorescence staining; and analyzed urine and serum of knockout and wild-type animals. We also used electrophysiologic studies to investigate the functionality of isolated proximal tubules, and studied compensatory regulation by pharmacologic intervention, RNA sequencing analysis, Western blot, immunofluorescence staining, and respirometry. Results Mice deficient in claudin-10a were fertile and without overt phenotypes. Upon knockout, claudin-10a was replaced by claudin-2 in all proximal tubule segments. Electrophysiology showed conversion from paracellular anion preference to cation preference and a loss of paracellular Cl- over HCO3- preference. As a consequence, there was tubular retention of calcium and magnesium, higher urine pH, and mild hypermagnesemia. A comparison of other urine and serum parameters under control conditions and sequential pharmacologic transport inhibition, as well as unchanged fractional lithium excretion, suggested compensative measures in proximal and distal tubular segments. Changes in proximal tubular oxygen handling and differential expression of genes regulating fatty acid metabolism indicated proximal tubular adaptation. Western blot and immunofluorescence revealed alterations in distal tubular transport. Conclusions Claudin-10a is the major paracellular anion channel in the proximal tubule and its deletion causes calcium and magnesium hyperreabsorption by claudin-2 redistribution. Transcellular transport in proximal and distal segments and proximal tubular metabolic adaptation compensate for loss of paracellular anion permeability.
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Affiliation(s)
- Tilman Breiderhoff
- T Breiderhoff, Department of Pediatrics, Division of Gastroenterology, Nephrology and Metabolic Medicine, Charite Universitatsmedizin Berlin, Berlin, Germany
| | - Nina Himmerkus
- N Himmerkus, Institute of Physiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Luca Meoli
- L Meoli, Clinical Physiology / Div. of Nutritional Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Anja Fromm
- A Fromm, Clinical Physiology / Div. of Nutritional Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Sebastian Sewerin
- S Sewerin, Division of Nephrology, University of Leipzig Medical Center, Leipzig, Germany
| | - Natalia Kriuchkova
- N Kriuchkova, Institute for Functional Anatomy, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Oliver Nagel
- O Nagel, Clinical Physiology / Div. of Nutritional Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Yury Ladilov
- Y Ladilov, Clinical Physiology / Div. of Nutritional Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Susanne Krug
- S Krug, Clinical Physiology / Div. of Nutritional Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Catarina Quintanova
- C Quintanova, Institute of Physiology, Christian-Albrechts-Universitat zu Kiel, Kiel, Germany
| | - Meike Stumpp
- M Stumpp, Zoological Institute, Comparative Immunobiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Dieter Garbe-Schönberg
- D Garbe-Schönberg, Institute of Geosciences, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Ulrike Westernströer
- U Westernströer, Institute of Geosciences, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Cosima Merkel
- C Merkel, Institute of Physiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Merle Brinkhus
- M Brinkhus, Institute of Physiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Janine Altmüller
- J Altmüller, Cologne Center for Genomics, University of Cologne, Koln, Germany
| | - Michal Schweiger
- M Schweiger, Cologne Center for Genomics, University of Cologne, Koln, Germany
| | - Dominik Mueller
- D Mueller, Department of Pediatrics, Division of Gastroenterology, Nephrology and Metabolic Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Kerim Mutig
- K Mutig, Institute for Functional Anatomy, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Markus Morawski
- M Morawski, Leipzig University Paul Flechsig Institute of Brain Research, Leipzig, Germany
| | - Jan Halbritter
- J Halbritter, Division of Nephrology, University of Leipzig Medical Center, Leipzig, Germany
| | - Susanne Milatz
- S Milatz, Institute of Physiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Markus Bleich
- M Bleich, Institute of Physiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Dorothee Günzel
- D Günzel, Clinical Physiology / Div. of Nutritional Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
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13
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Kouyoumdzian NM, Kim G, Rudi MJ, Rukavina Mikusic NL, Fernández BE, Choi MR. Clues and new evidences in arterial hypertension: unmasking the role of the chloride anion. Pflugers Arch 2021; 474:155-176. [PMID: 34966955 DOI: 10.1007/s00424-021-02649-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 02/06/2023]
Abstract
The present review will focus on the role of chloride anion in cardiovascular disease, with special emphasis in the development of hypertensive disease and vascular inflammation. It is known that acute and chronic overload of sodium chloride increase blood pressure and have pro-inflammatory and pro-fibrotic effects on different target organs, but it is unknown how chloride may influence these processes. Chloride anion is the predominant anion in the extracellular fluid and its intracellular concentration is dynamically regulated. As the queen of the electrolytes, it is of crucial importance to understand the physiological mechanisms that regulate the cellular handling of this anion including the different transporters and cellular chloride channels, which exert a variety of functions, such as regulation of cellular proliferation, differentiation, migration, apoptosis, intracellular pH and cellular redox state. In this article, we will also review the relationship between dietary, serum and intracellular chloride and how these different sources of chloride in the organism are affected in hypertension and their impact on cardiovascular disease. Additionally, we will discuss the approach of potential strategies that affect chloride handling and its potential effect on cardiovascular system, including pharmacological blockade of chloride channels and non-pharmacological interventions by replacing chloride by another anion.
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Affiliation(s)
- Nicolás Martín Kouyoumdzian
- Universidad de Buenos Aires, CONICET, Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional (IATIMET), Buenos Aires, Argentina.
| | - Gabriel Kim
- Facultad de Farmacia Y Bioquímica, Departamento de Ciencias Biológicas, Cátedra de Anatomía e Histología, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María Julieta Rudi
- Facultad de Farmacia Y Bioquímica, Departamento de Ciencias Biológicas, Cátedra de Anatomía e Histología, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Natalia Lucía Rukavina Mikusic
- Facultad de Farmacia Y Bioquímica, Departamento de Ciencias Biológicas, Cátedra de Anatomía e Histología, Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | - Marcelo Roberto Choi
- Universidad de Buenos Aires, CONICET, Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional (IATIMET), Buenos Aires, Argentina.,Facultad de Farmacia Y Bioquímica, Departamento de Ciencias Biológicas, Cátedra de Anatomía e Histología, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto Universitario de Ciencias de La Salud, Fundación H.A. Barceló, Buenos Aires, Argentina
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14
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Kapłon-Cieślicka A, Soloveva A, Mareev Y, Cabac-Pogorevici I, Verbrugge FH, Vardas P. Hyponatraemia in heart failure: time for new solutions? Heart 2021; 108:1179-1185. [PMID: 34903584 DOI: 10.1136/heartjnl-2021-320277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 11/18/2021] [Indexed: 11/04/2022] Open
Abstract
Hyponatraemia is very common in heart failure (HF), especially in decompensated patients. It is associated with increased mortality and morbidity and considered a marker of advanced disease. Recognition of hyponatraemia and its causes may help guide treatment strategy. Historically, therapy has primarily focused on water restriction, decongestion with loop diuretics in case of volume overload (dilutional hyponatraemia) and sodium repletion in case of depletion. In this review, we summarise the potential benefits of established and emerging HF therapies on sodium homeostasis, with a focus on dual vasopressin antagonists, angiotensin receptor-neprilysin inhibitors, sodium-glucose cotransporter 2 inhibitors and hypertonic saline, and propose a potential therapeutic approach for hyponatraemia in HF.
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Affiliation(s)
| | - Anzhela Soloveva
- Department of Cardiology, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation
| | - Yura Mareev
- Department of Cardiology, National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russian Federation.,Robertson Centre for Biostatistics, University of Glasgow, Glasgow, UK
| | - Irina Cabac-Pogorevici
- Department of Cardiology, State University of Medicine and Pharmacy 'Nicolae Testemitanu', Chisinau, Moldova (the Republic of)
| | - Frederik Hendrik Verbrugge
- Department of Cardiology, Centre for Cardiovascular Diseases, University Hospital Brussels, Jette, Belgium.,Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Panagiotis Vardas
- Heart Sector, Hygeia Hospitals Groups, Athens, Greece.,Medical School, Cardiology Department, University of Crete, Heraclion, Greece
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15
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Sudarikova A, Vasileva V, Sultanova R, Ilatovskaya D. Recent advances in understanding ion transport mechanisms in polycystic kidney disease. Clin Sci (Lond) 2021; 135:2521-2540. [PMID: 34751394 PMCID: PMC8589009 DOI: 10.1042/cs20210370] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 10/15/2021] [Accepted: 10/26/2021] [Indexed: 12/18/2022]
Abstract
This review focuses on the most recent advances in the understanding of the electrolyte transport-related mechanisms important for the development of severe inherited renal disorders, autosomal dominant (AD) and recessive (AR) forms of polycystic kidney disease (PKD). We provide here a basic overview of the origins and clinical aspects of ARPKD and ADPKD and discuss the implications of electrolyte transport in cystogenesis. Special attention is devoted to intracellular calcium handling by the cystic cells, with a focus on polycystins and fibrocystin, as well as other calcium level regulators, such as transient receptor potential vanilloid type 4 (TRPV4) channels, ciliary machinery, and purinergic receptor remodeling. Sodium transport is reviewed with a focus on the epithelial sodium channel (ENaC), and the role of chloride-dependent fluid secretion in cystic fluid accumulation is discussed. In addition, we highlight the emerging promising concepts in the field, such as potassium transport, and suggest some new avenues for research related to electrolyte handling.
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Affiliation(s)
| | | | - Regina F. Sultanova
- Saint-Petersburg State Chemical Pharmaceutical University, St. Petersburg, Russia
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16
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Roesch S, Rasp G, Sarikas A, Dossena S. Genetic Determinants of Non-Syndromic Enlarged Vestibular Aqueduct: A Review. Audiol Res 2021; 11:423-442. [PMID: 34562878 PMCID: PMC8482117 DOI: 10.3390/audiolres11030040] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/02/2021] [Accepted: 08/24/2021] [Indexed: 12/13/2022] Open
Abstract
Hearing loss is the most common sensorial deficit in humans and one of the most common birth defects. In developed countries, at least 60% of cases of hearing loss are of genetic origin and may arise from pathogenic sequence alterations in one of more than 300 genes known to be involved in the hearing function. Hearing loss of genetic origin is frequently associated with inner ear malformations; of these, the most commonly detected is the enlarged vestibular aqueduct (EVA). EVA may be associated to other cochleovestibular malformations, such as cochlear incomplete partitions, and can be found in syndromic as well as non-syndromic forms of hearing loss. Genes that have been linked to non-syndromic EVA are SLC26A4, GJB2, FOXI1, KCNJ10, and POU3F4. SLC26A4 and FOXI1 are also involved in determining syndromic forms of hearing loss with EVA, which are Pendred syndrome and distal renal tubular acidosis with deafness, respectively. In Caucasian cohorts, approximately 50% of cases of non-syndromic EVA are linked to SLC26A4 and a large fraction of patients remain undiagnosed, thus providing a strong imperative to further explore the etiology of this condition.
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Affiliation(s)
- Sebastian Roesch
- Department of Otorhinolaryngology, Head and Neck Surgery, Paracelsus Medical University, 5020 Salzburg, Austria; (S.R.); (G.R.)
| | - Gerd Rasp
- Department of Otorhinolaryngology, Head and Neck Surgery, Paracelsus Medical University, 5020 Salzburg, Austria; (S.R.); (G.R.)
| | - Antonio Sarikas
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, 5020 Salzburg, Austria;
| | - Silvia Dossena
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, 5020 Salzburg, Austria;
- Correspondence: ; Tel.: +43-(0)662-2420-80564
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17
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Cao Y, Donaldson R, Lee D. "Summer hypokalemia" as an initial presentation of cystic fibrosis in a morbidly obese African American adult: case report. BMC Nephrol 2020; 21:462. [PMID: 33160331 PMCID: PMC7648400 DOI: 10.1186/s12882-020-02130-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 10/27/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Most patients with cystic fibrosis (CF) present with respiratory or digestive symptoms. About 3% of patients have electrolyte disturbances at the time of diagnosis, but most of the described cases presenting with this manifestation have been in children. Only 3 adult patients are identified in the literature who first presented with hypokalemia. We describe a morbidly obese African American adult who presented with severe hypokalemia and metabolic alkalosis, which eventually led to the diagnosis of CF after multiple hospitalizations over 4 consecutive summers. Besides being the first African American adult with this presentation, he had the highest BMI, lowest serum potassium, highest pH, and highest bicarbonate level. CASE PRESENTATION In the summer of 2015, a 26 year-old African American man presented to the hospital for generalized weakness. His BMI was 54 kg/M2, and he had been on a special diet for a few months with a weight loss of 50 pounds. He sweated profusely while working as a chef. Laboratory tests showed severe hypokalemia and metabolic alkalosis. Further work-up pointed toward extrarenal losses of potassium. He was treated with intravenous normal saline and potassium chloride. After discharge, his potassium level remained normal through the winter while the potassium was tapered off. However, over the following three summers, he repeatedly presented to hospitals for the same problems. Cystic fibrosis was suspected and confirmed by an abnormal pilocarpine sweat test. Gene test revealed two mutations of cystic fibrosis transmembrane conductance regulator (CFTR). Thereafter, his potassium level remained normal with potassium replacement during summertime. Unexpectedly, however, his BMI rose to 83 kg/M2 after he stopped the special diet for weight reduction. The reason for the delayed diagnosis is discussed. CONCLUSION We present an exceedingly rare case of CF in a morbidly obese African American adult male whose only manifestation of CF was hypokalemia and metabolic alkalosis. Clinicians should keep an open mind to the diagnosis of CF in ethnically diverse populations, even if it seems unlikely at first glance. For "summer hypokalemia", consider cystic fibrosis.
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Affiliation(s)
- Yangming Cao
- Divisions of Nephrology, Department of Internal Medicine, UCSF Fresno Center for Medical Education and Research, 155 N Fresno St, Fresno, CA, 93701, USA. .,The Nephrology Group, 568 E Herndon Ave, Suite 201, Fresno, CA, 93720, USA.
| | - Rachel Donaldson
- Divisions of Pulmonology, Department of Internal Medicine, UCSF Fresno Center for Medical Education and Research, 155 N Fresno St, Fresno, CA, 93701, USA
| | - David Lee
- Divisions of Pulmonology, Department of Internal Medicine, UCSF Fresno Center for Medical Education and Research, 155 N Fresno St, Fresno, CA, 93701, USA
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18
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Redant S, De Bels D, Barbance O, Loulidi G, Honoré PM. Extracorporeal CO2 Removal Integrated within a Continuous Renal Replacement Circuit Offers Multiple Advantages. Blood Purif 2020; 50:9-16. [PMID: 32585671 DOI: 10.1159/000507875] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/13/2020] [Indexed: 11/19/2022]
Abstract
Extracorporeal CO2 removal within a continuous renal replacement therapy circuit offers multiple advantages for the regulation of the CO2 extraction. The authors review the impact of the dialysate solution, the buffer, and the anticoagulation on CO2 removal. They propose a theoretical model of the ideal circuit for the optimization of CO2 extraction.
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Affiliation(s)
- Sébastien Redant
- ICU Department, Brugmann University Hospital, Brussels, Belgium,
| | - David De Bels
- ICU Department, Brugmann University Hospital, Brussels, Belgium
| | - Oceane Barbance
- ICU Department, Brugmann University Hospital, Brussels, Belgium
| | - Ghalil Loulidi
- ICU Department, Brugmann University Hospital, Brussels, Belgium
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19
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Abstract
Metabolic alkalosis is a very commonly encountered acid-base disorder that may be generated by a variety of exogenous and/or endogenous, pathophysiologic mechanisms. Multiple mechanisms are also responsible for the persistence, or maintenance, of metabolic alkalosis. Understanding these generation and maintenance mechanisms helps direct appropriate intervention and correction of this disorder. The framework utilized in this review is based on the ECF volume-centered approach popularized by Donald Seldin and Floyd Rector in the 1970s. Although many subsequent scientific discoveries have advanced our understanding of the pathophysiology of metabolic alkalosis, that framework continues to be a valuable and relatively straightforward diagnostic and therapeutic model.
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Affiliation(s)
- Michael Emmett
- Divisions of Internal Medicine and Nephrology, Department of Medicine, Baylor University Medical Center at Dallas, Dallas, Texas
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20
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Komaru Y, Doi K, Matsuura R, Yoshida T, Miyamoto Y, Yoshimoto K, Nangaku M. Urinary chloride concentration as a prognostic marker in critically ill patients. Nephrology (Carlton) 2019; 25:384-389. [PMID: 31674129 DOI: 10.1111/nep.13674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/17/2019] [Accepted: 10/11/2019] [Indexed: 12/23/2022]
Abstract
AIM Associations have been reported among serum chloride concentration, mortality and incidence of acute kidney injury (AKI) in intensive care units (ICU). This study aimed to examine associations among urinary chloride, mortality, and AKI incidence in ICU patients. METHODS A retrospective observational study was conducted among medical-surgical ICU in a tertiary hospital wherein 170 consecutive ICU patients were evaluated from October 2015 to March 2016 and 116 patients were enrolled. Serial data of serum and urine electrolytes from day 1 to day 4 of ICU admission were examined. The primary and secondary outcomes were ICU mortality and incidence of AKI in the ICU, respectively. RESULTS Among the 116 enrolled patients, 15 (13%) died during their ICU stay. Although serum and urinary sodium and potassium on day 1 did not significantly differ between ICU survivors and non-survivors, urinary chloride concentration on day 1 was significantly lower in non-survivors. Receiver operating characteristic analysis showed that the cutoff value of day 1 urinary chloride concentration for prediction of ICU mortality was 53 mEq/L. The lower urinary chloride concentration group on day 1 showed a significantly lower survival rate, even in long-term follow-up, compared with the higher urinary chloride group. Addition of day 1 urinary chloride concentration improved prediction of AKI incidence in the ICU by Sequential Organ Failure Assessment score alone. CONCLUSION Lower urinary chloride concentration was associated with increased mortality and incidence of AKI in the ICU. Further investigation is necessary to clarify the mechanism of urinary chloride regulation.
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Affiliation(s)
- Yohei Komaru
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Kent Doi
- Department of Acute Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Ryo Matsuura
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Teruhiko Yoshida
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Yoshihisa Miyamoto
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Kohei Yoshimoto
- Department of Acute Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
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21
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Molecular basis of hearing loss associated with enlarged vestibular aqueduct. JOURNAL OF BIO-X RESEARCH 2019. [DOI: 10.1097/jbr.0000000000000032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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22
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Nair AV, Yanhong W, Paunescu TG, Bouley R, Brown D. Sex-dependent differences in water homeostasis in wild-type and V-ATPase B1-subunit deficient mice. PLoS One 2019; 14:e0219940. [PMID: 31386675 PMCID: PMC6684071 DOI: 10.1371/journal.pone.0219940] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 07/03/2019] [Indexed: 12/19/2022] Open
Abstract
Men tend to dehydrate more than women after prolonged exercise, possibly due to lower water intake and higher perspiration rate. Women are prone to exercise-associated hyponatremia, primarily attributed to the higher water consumption causing hypervolemia. Since aquaporin-2 (AQP2) water channels in the kidney collecting duct (CD) principal cells (PCs) are involved in maintaining water balance, we investigated their role in sex-dependent water homeostasis in wild-type (WT) C57BL/6 mice. Because CD intercalated cells (ICs) may also be involved in water balance, we also assessed the urine concentrating ability of V-ATPase B1 subunit-deficient (Atp6v1b1-/-) mice. Upon 12-hour water deprivation, urine osmolality increased by 59% in WT female mice and by only 28% in males. This difference was abolished in Atp6v1b1-/- mice, in which dehydration induced a ~30% increase in urine osmolarity in both sexes. AQP2 levels were highest in WT females; female Atp6v1b1-/- mice had substantially lower AQP2 expression than WT females, comparable to the low AQP2 levels seen in both Atp6v1b1-/- and WT males. After dehydration, AQP2 relocates towards the PC apical pole, especially in the inner stripe and inner medulla, and to a greater extent in WT females than in WT males. This apparent sex-dependent concentrating advantage was absent in Atp6v1b1-/- females, whose reduced AQP2 apical relocation was similar to WT males. Accordingly, female mice concentrate urine better than males upon dehydration due to increased AQP2 expression and mobilization. Moreover, our data support the involvement of ICs in water homeostasis, at least partly mediated by V-ATPase, in a sex-dependent manner.
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Affiliation(s)
- Anil V. Nair
- Program in Membrane Biology, Center for Systems Biology and Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
- * E-mail:
| | - Wei Yanhong
- Program in Membrane Biology, Center for Systems Biology and Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Teodor G. Paunescu
- Program in Membrane Biology, Center for Systems Biology and Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Richard Bouley
- Program in Membrane Biology, Center for Systems Biology and Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Dennis Brown
- Program in Membrane Biology, Center for Systems Biology and Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
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23
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Seidler U, Nikolovska K. Slc26 Family of Anion Transporters in the Gastrointestinal Tract: Expression, Function, Regulation, and Role in Disease. Compr Physiol 2019; 9:839-872. [DOI: 10.1002/cphy.c180027] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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24
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Najafi M, Kordi-Tamandani DM, Behjati F, Sadeghi-Bojd S, Bakey Z, Karimiani EG, Schüle I, Azarfar A, Schmidts M. Mimicry and well known genetic friends: molecular diagnosis in an Iranian cohort of suspected Bartter syndrome and proposition of an algorithm for clinical differential diagnosis. Orphanet J Rare Dis 2019; 14:41. [PMID: 30760291 PMCID: PMC6375149 DOI: 10.1186/s13023-018-0981-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 12/14/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Bartter Syndrome is a rare, genetically heterogeneous, mainly autosomal recessively inherited condition characterized by hypochloremic hypokalemic metabolic alkalosis. Mutations in several genes encoding for ion channels localizing to the renal tubules including SLC12A1, KCNJ1, BSND, CLCNKA, CLCNKB, MAGED2 and CASR have been identified as underlying molecular cause. No genetically defined cases have been described in the Iranian population to date. Like for other rare genetic disorders, implementation of Next Generation Sequencing (NGS) technologies has greatly facilitated genetic diagnostics and counseling over the last years. In this study, we describe the clinical, biochemical and genetic characteristics of patients from 15 Iranian families with a clinical diagnosis of Bartter Syndrome. RESULTS Age range of patients included in this study was 3 months to 6 years and all patients showed hypokalemic metabolic alkalosis. 3 patients additionally displayed hypercalciuria, with evidence of nephrocalcinosis in one case. Screening by Whole Exome Sequencing (WES) and long range PCR revealed that 12/17 patients (70%) had a deletion of the entire CLCNKB gene that was previously identified as the most common cause of Bartter Syndrome in other populations. 4/17 individuals (approximately 25% of cases) were found to suffer in fact from pseudo-Bartter syndrome resulting from congenital chloride diarrhea due to a novel homozygous mutation in the SLC26A3 gene, Pendred syndrome due to a known homozygous mutation in SLC26A4, Cystic Fibrosis (CF) due to a novel mutation in CFTR and apparent mineralocorticoid excess syndrome due to a novel homozygous loss of function mutation in HSD11B2 gene. 1 case (5%) remained unsolved. CONCLUSIONS Our findings demonstrate deletion of CLCNKB is the most common cause of Bartter syndrome in Iranian patients and we show that age of onset of clinical symptoms as well as clinical features amongst those patients are variable. Further, using WES we were able to prove that nearly 1/4 patients in fact suffered from Pseudo-Bartter Syndrome, reversing the initial clinical diagnosis with important impact on the subsequent treatment and clinical follow up pathway. Finally, we propose an algorithm for clinical differential diagnosis of Bartter Syndrome.
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Affiliation(s)
- Maryam Najafi
- Genome Research Division, Human Genetics department, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525KL, Nijmegen, The Netherlands.,Departement of Biology, University of Sistan and Baluchestan, Zahedan, Iran
| | | | - Farkhondeh Behjati
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Simin Sadeghi-Bojd
- Children and Adolescents Health Research Center, resistant tuberculosis institute, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Zeineb Bakey
- Genome Research Division, Human Genetics department, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525KL, Nijmegen, The Netherlands.,Center for Pediatrics and Adolescent Medicine, Freiburg University Hospital, Freiburg University Faculty of Medicine, Mathildenstrasse 1, 79112, Freiburg, Germany
| | - Ehsan Ghayoor Karimiani
- Razavi Cancer Research, Razavi Hospital, Imam Reza International University, Mashhad, Iran.,Next Generation Genetic Polyclinic, Mashhad, Iran
| | - Isabel Schüle
- Center for Pediatrics and Adolescent Medicine, Freiburg University Hospital, Freiburg University Faculty of Medicine, Mathildenstrasse 1, 79112, Freiburg, Germany
| | - Anoush Azarfar
- Department of Pediatrics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Miriam Schmidts
- Genome Research Division, Human Genetics department, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525KL, Nijmegen, The Netherlands. .,Center for Pediatrics and Adolescent Medicine, Freiburg University Hospital, Freiburg University Faculty of Medicine, Mathildenstrasse 1, 79112, Freiburg, Germany. .,Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, 79112, Freiburg, Germany.
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25
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Rein JL, Coca SG. "I don't get no respect": the role of chloride in acute kidney injury. Am J Physiol Renal Physiol 2018; 316:F587-F605. [PMID: 30539650 DOI: 10.1152/ajprenal.00130.2018] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Acute kidney injury (AKI) is a major public health problem that complicates 10-40% of hospital admissions. Importantly, AKI is independently associated with increased risk of progression to chronic kidney disease, end-stage renal disease, cardiovascular events, and increased risk of in-hospital and long-term mortality. The chloride content of intravenous fluid has garnered much attention over the last decade, as well as its association with excess use and adverse outcomes, including AKI. Numerous studies show that changes in serum chloride concentration, independent of serum sodium and bicarbonate, are associated with increased risk of AKI, morbidity, and mortality. This comprehensive review details the complex renal physiology regarding the role of chloride in regulating renal blood flow, glomerular filtration rate, tubuloglomerular feedback, and tubular injury, as well as the findings of clinical research related to the chloride content of intravenous fluids, changes in serum chloride concentration, and AKI. Chloride is underappreciated in both physiology and pathophysiology. Although the exact mechanism is debated, avoidance of excessive chloride administration is a reasonable treatment option for all patients and especially in those at risk for AKI. Therefore, high-risk patients and those with "incipient" AKI should receive balanced solutions rather than normal saline to minimize the risk of AKI.
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Affiliation(s)
- Joshua L Rein
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai , New York, New York
| | - Steven G Coca
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai , New York, New York
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Pendred, pendrin, pseudohypoaldosteronism type II, and renal tubular acidosis. Kidney Int 2018; 94:457-459. [DOI: 10.1016/j.kint.2018.05.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 05/18/2018] [Indexed: 11/18/2022]
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Barone S, Xu J, Zahedi K, Brooks M, Soleimani M. Probenecid Pre-treatment Downregulates the Kidney Cl -/HCO 3- Exchanger (Pendrin) and Potentiates Hydrochlorothiazide-Induced Diuresis. Front Physiol 2018; 9:849. [PMID: 30050451 PMCID: PMC6050369 DOI: 10.3389/fphys.2018.00849] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 06/14/2018] [Indexed: 01/14/2023] Open
Abstract
Background: Probenecid is a uricosuric agent that in addition to exerting a positive ionotropic effect in the heart, blocks the ATP transporter Pannexin 1 and inhibits the Cl-/HCO3- exchanger, pendrin. In the kidney, pendrin blunts the loss of salt wasting secondary to the inhibition of the thiazide-sensitive Na+-Cl- co-transporter (NCC/SLC12A3). Hypothesis: Pre-treatment with probenecid down-regulates pendrin; therefore, leaving NCC as the main salt absorbing transporter in the distal nephron, and hence enhances the hydrochlorothiazide (HCTZ)-induced diuresis. Methods: Daily balance studies, blood and urine chemical analysis, immunofluorescence, as well as western and northern blot analyses were utilized to examine the effects of probenecid alone (at 250 mg/kg/day) or in combination with HCTZ (at 40 mg/kg/day) on kidney function and on salt and water transporters in the collecting duct. Results: Male Sprague Dawley rats were subjected to three different protocols: (1) HCTZ for 4 days, (2) probenecid for 10 days, and (3) primed with probenecid for 6 days followed by probenecid and HCTZ for 4 additional days. Treatment protocol 1 (HCTZ for 4 days) only mildly increased the urine volume (U Vol) from a baseline of 9.8-13.4 ml/day. In response to treatment protocol 2 (probenecid for 10 days), U Vol increased to 15.9 ml/24 h. Treatment protocol 3 (probenecid for 6 days followed by probenecid and HCTZ for 4 additional days) increased the U Vol to 42.9 ml/day on day 4 of co-treatment with HCTZ and probenecid (compared to probenecid p = 0.003, n = 5 or HCTZ alone p = 0.001, n = 5). Probenecid treatment at 250 mg/kg/day downregulated the expression of pendrin and led to a decrease in AQP2 expression. Enhanced diuresis by probenecid plus HCTZ was not associated with volume depletion. Conclusion: Probenecid pre-treatment downregulates pendrin and robustly enhances diuresis by HCTZ-mediated NCC inhibition in kidney.
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Affiliation(s)
- Sharon Barone
- Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
- Research Services, VA Medical Center, Cincinnati, OH, United States
| | - Jie Xu
- Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
- Center on Genetics of Transport and Epithelial Biology, University of Cincinnati, Cincinnati, OH, United States
| | - Kamyar Zahedi
- Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
- Research Services, VA Medical Center, Cincinnati, OH, United States
| | - Marybeth Brooks
- Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
| | - Manoocher Soleimani
- Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
- Research Services, VA Medical Center, Cincinnati, OH, United States
- Center on Genetics of Transport and Epithelial Biology, University of Cincinnati, Cincinnati, OH, United States
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Affiliation(s)
- David H. Ellison
- Oregon Clinical & Translational Research Institute, Oregon Health & Science University and VA Portland Health Care System, Portland, OR
| | - G. Michael Felker
- Duke University School of Medicine and Duke Clinical Research Institute, Durham, NC
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Anuk AT, Kose S, Fırat C, Ozer E, Altunyurt S. Pendrin Expression in Preeclampsia: A Prospective Immunohistochemical Staining Study on Placental Bed Biopsies. Fetal Pediatr Pathol 2017; 36:364-372. [PMID: 28949777 DOI: 10.1080/15513815.2017.1346016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION To assess the pendrin expression density in placental bed biopsies from preeclampsia cases in comparison with healthy term controls. MATERIAL AND METHODS A prospective case-control study with 106 placental bed biopsies obtained during cesarean deliveries. Pendrin expression was evaluated by immunohistochemical staining in different hypertensive disorders of pregnancy. RESULTS Pendrin immunostaining frequency was higher in the hypertensive disorders group (p: 0.024), which was a result of the high frequency in the early-onset preeclampsia group. Uterine artery pulsatility indices were higher in pendrin positive patients than in the negatives in the case group. Gravidity was not found to affect the pendrin expression frequency in the placental bed. CONCLUSION Placental ischemia seems to be an important determinant of pendrin expression in pregnant decidua. Increased pendrin density in early-onset preeclampsia could be a pathogenetic mechanism in or a part of the adaptational response to the development of the hypertension.
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Affiliation(s)
- Ali T Anuk
- a Department of Obstetrics and Gynecology , Dokuz Eylul University School of Medicine , Balcova, Izmir , Turkey
| | - Semir Kose
- b Division of Perinatology, Department of Obstetrics and Gynecology , Dokuz Eylul University School of Medicine , Balcova, Izmir , Turkey
| | - Canan Fırat
- c Department of Medical Pathology , Dokuz Eylul University School of Medicine , Balcova, Izmir , Turkey
| | - Erdener Ozer
- c Department of Medical Pathology , Dokuz Eylul University School of Medicine , Balcova, Izmir , Turkey
| | - Sabahattin Altunyurt
- b Division of Perinatology, Department of Obstetrics and Gynecology , Dokuz Eylul University School of Medicine , Balcova, Izmir , Turkey
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Edwards A, Crambert G. Versatility of NaCl transport mechanisms in the cortical collecting duct. Am J Physiol Renal Physiol 2017; 313:F1254-F1263. [PMID: 28877883 DOI: 10.1152/ajprenal.00369.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 08/16/2017] [Accepted: 08/31/2017] [Indexed: 12/16/2022] Open
Abstract
The cortical collecting duct (CCD) forms part of the aldosterone-sensitive distal nephron and plays an essential role in maintaining the NaCl balance and acid-base status. The CCD epithelium comprises principal cells as well as different types of intercalated cells. Until recently, transcellular Na+ transport was thought to be restricted to principal cells, whereas (acid-secreting) type A and (bicarbonate-secreting) type B intercalated cells were associated with the regulation of acid-base homeostasis. This review describes how this traditional view has been upended by several discoveries in the past decade. A series of studies has shown that type B intercalated cells can mediate electroneutral NaCl reabsorption by a mechanism involving Na+-dependent and Na+-independent Cl-/[Formula: see text] exchange, and that is energetically driven by basolateral vacuolar H+-ATPase pumps. Other research indicates that type A intercalated cells can mediate NaCl secretion, through a bumetanide-sensitive pathway that is energized by apical H+,K+-ATPase type 2 pumps operating as Na+/K+ exchangers. We also review recent findings on the contribution of the paracellular route to NaCl transport in the CCD. Last, we describe cross-talk processes, by which one CCD cell type impacts Na+/Cl- transport in another cell type. The mechanisms that have been identified to date demonstrate clearly the interdependence of NaCl and acid-base transport systems in the CCD. They also highlight the remarkable versatility of this nephron segment.
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Affiliation(s)
- Aurélie Edwards
- Sorbonne Universités, UPMC Univ Paris 06, Université Paris Descartes, Sorbonne Paris Cité, INSERM UMRS 1138, CNRS ERL 8228, Centre de Recherche des Cordeliers, Paris, France; and .,Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Gilles Crambert
- Sorbonne Universités, UPMC Univ Paris 06, Université Paris Descartes, Sorbonne Paris Cité, INSERM UMRS 1138, CNRS ERL 8228, Centre de Recherche des Cordeliers, Paris, France; and
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Fenton RA, Poulsen SB, de la Mora Chavez S, Soleimani M, Dominguez Rieg JA, Rieg T. Renal tubular NHE3 is required in the maintenance of water and sodium chloride homeostasis. Kidney Int 2017; 92:397-414. [PMID: 28385297 DOI: 10.1016/j.kint.2017.02.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 01/25/2017] [Accepted: 02/02/2017] [Indexed: 11/30/2022]
Abstract
The sodium/proton exchanger isoform 3 (NHE3) is expressed in the intestine and the kidney, where it facilitates sodium (re)absorption and proton secretion. The importance of NHE3 in the kidney for sodium chloride homeostasis, relative to the intestine, is unknown. Constitutive tubule-specific NHE3 knockout mice (NHE3loxloxCre) did not show significant differences compared to control mice in body weight, blood pH or bicarbonate and plasma sodium, potassium, or aldosterone levels. Fluid intake, urinary flow rate, urinary sodium/creatinine, and pH were significantly elevated in NHE3loxloxCre mice, while urine osmolality and GFR were significantly lower. Water deprivation revealed a small urinary concentrating defect in NHE3loxloxCre mice on a control diet, exaggerated on low sodium chloride. Ten days of low or high sodium chloride diet did not affect plasma sodium in control mice; however, NHE3loxloxCre mice were susceptible to low sodium chloride (about -4 mM) or high sodium chloride intake (about +2 mM) versus baseline, effects without differences in plasma aldosterone between groups. Blood pressure was significantly lower in NHE3loxloxCre mice and was sodium chloride sensitive. In control mice, the expression of the sodium/phosphate co-transporter Npt2c was sodium chloride sensitive. However, lack of tubular NHE3 blunted Npt2c expression. Alterations in the abundances of sodium/chloride cotransporter and its phosphorylation at threonine 58 as well as the abundances of the α-subunit of the epithelial sodium channel, and its cleaved form, were also apparent in NHE3loxloxCre mice. Thus, renal NHE3 is required to maintain blood pressure and steady-state plasma sodium levels when dietary sodium chloride intake is modified.
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Affiliation(s)
- Robert A Fenton
- InterPrET Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Søren B Poulsen
- InterPrET Center, Department of Biomedicine, Aarhus University, Aarhus, Denmark; VA San Diego Healthcare System, San Diego, California, USA
| | | | - Manoocher Soleimani
- Department of Medicine, University of Cincinnati, Cincinnati, Ohio, USA; Research Services, Veterans Affairs Medical Center, Cincinnati, Ohio, USA
| | - Jessica A Dominguez Rieg
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida, USA
| | - Timo Rieg
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida, USA.
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The Caenorhabditis elegans Excretory System: A Model for Tubulogenesis, Cell Fate Specification, and Plasticity. Genetics 2017; 203:35-63. [PMID: 27183565 DOI: 10.1534/genetics.116.189357] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/07/2016] [Indexed: 12/12/2022] Open
Abstract
The excretory system of the nematode Caenorhabditis elegans is a superb model of tubular organogenesis involving a minimum of cells. The system consists of just three unicellular tubes (canal, duct, and pore), a secretory gland, and two associated neurons. Just as in more complex organs, cells of the excretory system must first adopt specific identities and then coordinate diverse processes to form tubes of appropriate topology, shape, connectivity, and physiological function. The unicellular topology of excretory tubes, their varied and sometimes complex shapes, and the dynamic reprogramming of cell identity and remodeling of tube connectivity that occur during larval development are particularly fascinating features of this organ. The physiological roles of the excretory system in osmoregulation and other aspects of the animal's life cycle are only beginning to be explored. The cellular mechanisms and molecular pathways used to build and shape excretory tubes appear similar to those used in both unicellular and multicellular tubes in more complex organs, such as the vertebrate vascular system and kidney, making this simple organ system a useful model for understanding disease processes.
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Fallahzadeh MA, Dormanesh B, Fallahzadeh MK, Roozbeh J, Fallahzadeh MH, Sagheb MM. Acetazolamide and Hydrochlorothiazide Followed by Furosemide Versus Furosemide and Hydrochlorothiazide Followed by Furosemide for the Treatment of Adults With Nephrotic Edema: A Randomized Trial. Am J Kidney Dis 2016; 69:420-427. [PMID: 28043731 DOI: 10.1053/j.ajkd.2016.10.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 10/09/2016] [Indexed: 11/11/2022]
Abstract
BACKGROUND Nephrotic edema is considered refractory if it does not respond to maximum or near-maximum doses of loop diuretics. This condition can be treated with loop diuretics and thiazides. However, animal studies show that the simultaneous downregulation of pendrin with acetazolamide and inhibition of the sodium-chloride cotransporter with hydrochlorothiazide generates significant diuresis, and furosemide administration following a pendrin inhibitor potentiates furosemide's diuretic effect. Therefore, we performed this study to compare the efficacy of acetazolamide and hydrochlorothiazide followed by furosemide versus furosemide and hydrochlorothiazide followed by furosemide for treatment of refractory nephrotic edema. STUDY DESIGN Randomized, double-blind, 2-arm, parallel trial. SETTING & PARTICIPANTS 20 patients with refractory nephrotic edema despite treatment with 80mg of furosemide daily and creatinine clearance > 60mL/min. INTERVENTION Patients were randomly assigned to 2 groups: group 1 (n=10) received 250mg of acetazolamide and 50mg of hydrochlorothiazide daily and group 2 (n=10) received 40mg of furosemide and 50mg of hydrochlorothiazide daily for 1 week in phase 1. In phase 2, both groups received 40mg of furosemide daily for 2 weeks. OUTCOMES The primary outcome was absolute change in weight before and at the end of each phase. MEASUREMENTS Weight and 24-hour urine volume at baseline and the end of each phase. RESULTS The mean weight decrease was of significantly larger magnitude in group 1 compared with group 2 at the end of phase 1 (-1.4±0.52 [SD] vs -0.65±0.41kg; P=0.001) and phase 2 (-1.6±0.84 vs -0.5±0.47kg; P=0.005). The increase in 24-hour urine volume was also significantly higher in group 1 at the end of phase 2. LIMITATIONS Small sample size, short follow-up duration, and lack of serum bicarbonate and chloride measurement. CONCLUSIONS Acetazolamide and hydrochlorothiazide followed by furosemide is more effective than furosemide and hydrochlorothiazide followed by furosemide for the treatment of refractory nephrotic edema.
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Affiliation(s)
- Mohammad Amin Fallahzadeh
- AJA University of Medical Sciences, Tehran, Iran; Shiraz Nephro-Urology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | | | - Jamshid Roozbeh
- Shiraz Nephro-Urology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Mohammad Mahdi Sagheb
- Shiraz Nephro-Urology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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Schulze Blasum B, Schröter R, Neugebauer U, Hofschröer V, Pavenstädt H, Ciarimboli G, Schlatter E, Edemir B. The kidney-specific expression of genes can be modulated by the extracellular osmolality. FASEB J 2016; 30:3588-3597. [PMID: 27464968 DOI: 10.1096/fj.201600319r] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/05/2016] [Indexed: 12/29/2022]
Abstract
With this study, we wanted to prove the hypothesis that the unique extracellular osmolality within the renal medulla modulates a specific gene expression pattern. The physiologic functions of the kidneys are mediated by the segment-specific expression of key proteins. So far, we have limited knowledge about the mechanisms that control this gene expression pattern. The hyperosmolality in the renal medullary interstitium is of major importance as a driving force for urine concentration. We made use of primarily cultured rat renal inner medullary collecting-duct cells and microarray analysis to identify genes affected by the environmental osmolality of the culture medium. We identified hundreds of genes that were either induced or repressed in expression by hyperosmolality in a time- and osmolality-dependent fashion. Further analysis demonstrated that many of them, physiologically, showed a kidney- and even collecting-duct-specific expression, including secreted proteins, kinases, and transcription factors. On the other hand, we identified factors, down-regulated in expression, that have a diuretic effect. In conclusion, the kidney is the only organ that has such a hyperosmotic environment, and study provides an excellent method for controlling tissue-specific gene expression.-Schulze Blasum, B., Schröter, R., Neugebauer, U., Hofschröer, V., Pavenstädt, H., Ciarimboli, G., Schlatter E., Edemir, B. The kidney-specific expression of genes can be modulated by the extracellular osmolality.
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Affiliation(s)
- Britta Schulze Blasum
- Department of Internal Medicine D, Experimental Nephrology, University of Münster, Münster, Germany
| | - Rita Schröter
- Department of Internal Medicine D, Experimental Nephrology, University of Münster, Münster, Germany
| | - Ute Neugebauer
- Department of Internal Medicine D, Experimental Nephrology, University of Münster, Münster, Germany
| | - Verena Hofschröer
- Institute of Physiology II, University of Münster, Münster, Germany; and
| | - Hermann Pavenstädt
- Department of Internal Medicine D, Experimental Nephrology, University of Münster, Münster, Germany
| | - Guiliano Ciarimboli
- Department of Internal Medicine D, Experimental Nephrology, University of Münster, Münster, Germany
| | - Eberhard Schlatter
- Department of Internal Medicine D, Experimental Nephrology, University of Münster, Münster, Germany
| | - Bayram Edemir
- Department of Internal Medicine D, Experimental Nephrology, University of Münster, Münster, Germany; Faculty of Medicine, Department of Hematology and Oncology, Faculty of Medicine, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
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Ensuring the Quality of Stem Cell-Derived In Vitro Models for Toxicity Testing. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 856:259-297. [DOI: 10.1007/978-3-319-33826-2_11] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Nakajima K, Oda E, Kanda E. The association of serum sodium and chloride levels with blood pressure and estimated glomerular filtration rate. Blood Press 2015; 25:51-7. [PMID: 26434759 DOI: 10.3109/08037051.2015.1090711] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND High serum sodium (sNa) concentrations may be associated with hypertension, which deteriorates kidney function. However, it is equivocal whether high sNa concentrations are associated with impaired kidney function independently of blood pressure (BP) or serum chloride (sCl). Therefore, we addressed this issue in an apparently healthy population. METHODS Clinical variables including estimated glomerular filtration rate (eGFR) were examined in 3603 men and women (aged 25-75 years) who underwent health-screening check-ups. sNa concentrations were classified into five categories. RESULTS Most parameters, including age and BP, increased with increasing sNa, whereas eGFR decreased. Logistic regression analysis showed that, compared with low-normal sNa (≤ 140 mEq/l), high sNa (≥ 144 mEq/l) was significantly associated with elevated BP (≥ 130/85 mmHg) even after adjustment for blood hematocrit, eGFR, serum potassium (sK) concentration and sCl. The highest sNa category was significantly associated with reduced eGFR (< 60 ml/min/1.73 m(2)) independently of elevated BP. Unlike adjustment for sK, adjustment for sCl strengthened the association between high sNa and elevated BP but attenuated the association between high sNa and reduced eGFR. CONCLUSIONS These results suggest that high sNa concentrations, even within the normal range, are independently associated with elevated BP and impaired kidney function. These associations may be substantially modified by sCl.
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Affiliation(s)
- Kei Nakajima
- a Division of Clinical Nutrition, Department of Medical Dietetics , Faculty of Pharmaceutical Sciences, Josai University , Sakado, Saitama , Japan.,b Department of Metabolism , Kuki General Hospital , Kuki, Saitama , Japan
| | - Eiji Oda
- c Medical Check-up Center, Tachikawa Medical Center , Nagaoka, Niigata , Japan
| | - Eiichiro Kanda
- d Department of Nephrology , Tokyo Kyosai Hospital , Meguro-ku, Tokyo , Japan
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