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Capolongo G, Damiano S, Suzumoto Y, Zacchia M, Rizzo M, Zona E, Pollastro RM, Simeoni M, Ciarcia R, Trepiccione F, Capasso G. Cyclosporin-induced hypertension is associated with the up-regulation of Na+-K+-2Cl- cotransporter (NKCC2). Nephrol Dial Transplant 2024; 39:297-304. [PMID: 37463050 PMCID: PMC10828191 DOI: 10.1093/ndt/gfad161] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Indexed: 02/01/2024] Open
Abstract
BACKGROUND The use of cyclosporin A (CsA) is hampered by the development of nephrotoxicity including hypertension, which is partially dependent on renal sodium retention. To address this issue, we have investigated in vivo sodium reabsorption in different nephron segments of CsA-treated rats through micropuncture study coupled to expression analyses of sodium transporters. To translate the findings in rats to human, kidney-transplanted patients having CsA treatment were enrolled in the study. METHODS Adult male Sprague-Dawley rats were treated with CsA (15 mg/kg/day) for 21 days, followed by micropuncture study and expression analyses of sodium transporters. CsA-treated kidney-transplanted patients with resistant hypertension were challenged with 50 mg furosemide. RESULTS CsA-treated rats developed hypertension associated with reduced glomerular filtration rate. In vivo microperfusion study demonstrated a significant decrease in rate of absolute fluid reabsorption in the proximal tubule but enhanced sodium reabsorption in the thick ascending limb of Henle's loop (TAL). Expression analyses of sodium transporters at the same nephron segments further revealed a reduction in Na+-H+ exchanger isoform 3 (NHE3) in the renal cortex, while TAL-specific, furosemide-sensitive Na+-K+-2Cl- cotransporter (NKCC2) and NHE3 were significantly upregulated in the inner stripe of outer medulla. CsA-treated patients had a larger excretion of urinary NKCC2 protein at basal condition, and higher diuretic response to furosemide, showing increased FeNa+, FeCl- and FeCa2+ compared with both healthy controls and FK506-treated transplanted patients. CONCLUSION Altogether, these findings suggest that up-regulation of NKCC2 along the TAL facilitates sodium retention and contributes to the development of CsA-induced hypertension.
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Affiliation(s)
- Giovanna Capolongo
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Sara Damiano
- Department of Veterinary Medicine and Animal Productions, University of Naples, Naples, Italy
| | - Yoko Suzumoto
- Biogem, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
| | - Miriam Zacchia
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Maria Rizzo
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Enrica Zona
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Rosa Maria Pollastro
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Mariadelina Simeoni
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Roberto Ciarcia
- Department of Veterinary Medicine and Animal Productions, University of Naples, Naples, Italy
| | - Francesco Trepiccione
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
- Biogem, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
| | - Giovambattista Capasso
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
- Biogem, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
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2
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Lombari P, Mallardo M, Petrazzuolo O, Amruthraj Nagoth J, Fiume G, Scanni R, Iervolino A, Damiano S, Coppola A, Borriello M, Ingrosso D, Perna AF, Zacchia M, Trepiccione F, Capasso G. miRNA-23a modulates sodium-hydrogen exchanger 1 expression: studies in medullary thick ascending limb of salt-induced hypertensive rats. Nephrol Dial Transplant 2023; 38:586-598. [PMID: 35921220 DOI: 10.1093/ndt/gfac232] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The kidney is the main organ in the pathophysiology of essential hypertension. Although most bicarbonate reabsorption occurs in the proximal tubule, the medullary thick ascending limb (mTAL) of the nephron also maintains acid-base balance by contributing to 25% of bicarbonate reabsorption. A crucial element in this regulation is the sodium-hydrogen exchanger 1 (NHE1), a ubiquitous membrane protein controlling intracellular pH, where proton extrusion is driven by the inward sodium flux. MicroRNA (miRNA) expression of hypertensive patients significantly differs from that of normotensive subjects. The aim of this study was to determine the functional role of miRNA alterations at the mTAL level. METHODS By miRNA microarray analysis, we identified miRNA expression profiles in isolated mTALs from high sodium intake-induced hypertensive rats (HSD) versus their normotensive counterparts (NSD). In vitro validation was carried out in rat mTAL cells. RESULTS Five miRNAs involved in the onset of salt-sensitive hypertension were identified, including miR-23a, which was bioinformatically predicted to target NHE1 mRNA. Data demonstrated that miRNA-23a is downregulated in the mTAL of HSD rats while NHE1 is upregulated. Consistently, transfection of an miRNA-23a mimic in an mTAL cell line, using a viral vector, resulted in NHE1 downregulation. CONCLUSION NHE1, a protein involved in sodium reabsorption at the mTAL level and blood pressure regulation, is upregulated in our model. This was due to a downregulation of miRNA-23a. Expression levels of this miRNA are influenced by high sodium intake in the mTALs of rats. The downregulation of miRNA-23a in humans affected by essential hypertension corroborate our data and point to the potential role of miRNA-23a in the regulation of mTAL function following high salt intake.
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Affiliation(s)
- Patrizia Lombari
- Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy.,Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Massimo Mallardo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | - Oriana Petrazzuolo
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Joseph Amruthraj Nagoth
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Giuseppe Fiume
- Departments of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Catanzaro, Italy
| | - Roberto Scanni
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Anna Iervolino
- Biogem, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
| | - Sara Damiano
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy
| | - Annapaola Coppola
- Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy
| | - Margherita Borriello
- Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy
| | - Diego Ingrosso
- Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy
| | - Alessandra F Perna
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Miriam Zacchia
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy
| | - Francesco Trepiccione
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy.,Biogem, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
| | - Giovambattista Capasso
- Division of Nephrology, Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy.,Biogem, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
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3
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Urinary proteomics reveals key markers of salt sensitivity in hypertensive patients during saline infusion. J Nephrol 2021; 34:739-751. [PMID: 33398797 DOI: 10.1007/s40620-020-00877-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 09/23/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Hypertension is a complex disease and is the major cause of cardiovascular complications. In the vast majority of individuals, the aetiology of elevated blood pressure (BP) cannot be determined, thus impairing optimized therapies and prognosis for individual patients. A more precise understanding of the molecular pathogenesis of hypertension remains a pressing priority for both basic and translational research. Here we investigated the effect of salt on naive hypertensive patients in order to better understand the salt intake-blood pressure relationship. METHODS Patients underwent an acute saline infusion and were defined as salt-sensitive or salt-resistant according to mean blood pressure changes. Urinary proteome changes during the salt load test were analysed by a label-free quantitative proteomics approach. RESULTS Our data show that salt-sensitive patients display equal sodium reabsorption as salt-resistant patients, as major sodium transporters show the same behaviour during the salt load. However, salt-sensitive patients regulate the renin angiotensin system (RAS) differently from salt-resistant patients, and upregulate proteins, as epidermal growth factor (EGF) and plasminogen activator, urokinase (PLAU), involved in the regulation of epithelial sodium channel ENaC activity. CONCLUSIONS Salt-sensitive and salt-resistant subjects have similar response to a saline/volume infusion as detected by urinary proteome. However, we identified glutamyl aminopeptidase (ENPEP), PLAU, EGF and Xaa-Pro aminopeptidase 2 precursor XPNPEP2 as key molecules of salt-sensitivity, through modulation of ENaC-dependent sodium reabsorption along the distal tubule.
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4
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Rani L, Saini S, Shukla N, Chowdhuri DK, Gautam NK. High sucrose diet induces morphological, structural and functional impairments in the renal tubules of Drosophila melanogaster: A model for studying type-2 diabetes mediated renal tubular dysfunction. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 125:103441. [PMID: 32735915 DOI: 10.1016/j.ibmb.2020.103441] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 07/13/2020] [Accepted: 07/20/2020] [Indexed: 06/11/2023]
Abstract
Continuous feeding of high dietary sugar is strongly associated with type 2 diabetes (T2D) and its secondary complications. Diabetic nephropathy (DN) is a major secondary complication that leads to glomerular and renal tubular dysfunction. The present study is aimed to investigate the effects of chronic exposure of high sugar diet (HSD) on renal tubules. Malpighian tubules (MTs), a renal organ of Drosophila, were used as a model in the study. Feeding of HSD develops T2D condition in Drosophila. The MTs showed structural abnormalities in 20 days of HSD fed flies. Impaired insulin signaling, oxidative stress, enhanced levels of AGE-RAGE and induction of apoptosis were observed in the MTs of these flies. Further, altered expression of transporters, enhanced uric acid level and reduced fluid secretion rate confirmed the impaired function of MTs in these flies. RNA-seq and RT-PCR analyses in the MTs of HSD fed-and control-flies revealed the altered expression of candidate genes that regulate several important pathways including extracellular matrix (ECM), advanced glycation end products-receptor for advanced glycation end products (AGE-RAGE), transforming growth factor β (TGF-β), galactose, starch and sucrose metabolism that are well known mediators of renal tubular dysfunction in DN patients. Disruption of insulin signaling in the MTs also causes renal tubular dysfunction similar to HSD fed flies. Overall, the study suggests that phenotypes observed in the MTs of HSD fed flies recapitulate several hallmarks of renal tubular dysfunction in DN patients. Therefore, we conclude that MTs of HSD fed flies may be used for deciphering the underlying mechanisms of T2D mediated renal tubular dysfunction.
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Affiliation(s)
- Lavi Rani
- Embryotoxicology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31 Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR Campus, Lucknow, India
| | - Sanjay Saini
- Embryotoxicology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31 Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India; Molecular and Human Genetics Laboratory, Department of Zoology, University of Lucknow, Lucknow, 226007, India
| | - Neha Shukla
- Embryotoxicology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31 Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India; Department of Urology and Renal Transplantation, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow, 226014, Uttar Pradesh, India
| | - Debapratim Kar Chowdhuri
- Embryotoxicology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31 Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR Campus, Lucknow, India
| | - Naveen Kumar Gautam
- Embryotoxicology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31 Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR Campus, Lucknow, India; Department of Urology and Renal Transplantation, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow, 226014, Uttar Pradesh, India.
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5
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Protective effects of 3,4-dihydroxyphenylethanol on spinal cord injury-induced oxidative stress and inflammation. Neuroreport 2019; 30:1016-1024. [PMID: 31503208 DOI: 10.1097/wnr.0000000000001318] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
3,4-Dihydroxyphenylethanol (DOPET) is a potent antioxidant polyphenolic compound. In this study, our objective was to investigate the underlying mechanism of the neuroprotective role of DOPET in attenuating spinal cord injury (SCI). Initially, SCI was induced by performing surgical laminectomy on the rats at T10-T12 level. Then, the neurological function-dependent locomotion was measured using Basso Beattie Bresnahan score, which declined in the SCI-induced group. Increased antioxidant levels such as superoxide dismutase, glutathione peroxidase, and glutathione along with other parameters such as increased lipid peroxidation (LPO) and myeloperoxidase (MPO) activities were all observed in the SCI group. Levels of proinflammatory cytokines such as tumor necrosis factor-α and interleukin-1β were upregulated in the serum and spinal cord tissue as observed on the immunoblot. Interestingly, protein levels of apoptotic markers such as Bax, cleaved caspase 3 and RT-PCR analysis-based mRNA level of pro-inflammatory cytokine, nuclear factor- κ activated B cells (NF-κB) were significantly upregulated in the spinal cord tissue. Nonetheless, antiapoptotic factor such as B-cell lymphoma 2 (Bcl-2) protein expression was downregulated in the same group. However, on administering 10 mg/kg of DOPET, the neuronal function was rescued, antioxidants were restored back to the normal levels, LPO and MPO activities were reduced in conjunction with downregulated levels of proinflammatory cytokines and apoptotic markers in the SCI group. These findings show that DOPET could potentially target multiple signalling pathways to combat SCI.
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6
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Gonzalez-Vicente A, Saez F, Monzon CM, Asirwatham J, Garvin JL. Thick Ascending Limb Sodium Transport in the Pathogenesis of Hypertension. Physiol Rev 2019; 99:235-309. [PMID: 30354966 DOI: 10.1152/physrev.00055.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The thick ascending limb plays a key role in maintaining water and electrolyte balance. The importance of this segment in regulating blood pressure is evidenced by the effect of loop diuretics or local genetic defects on this parameter. Hormones and factors produced by thick ascending limbs have both autocrine and paracrine effects, which can extend prohypertensive signaling to other structures of the nephron. In this review, we discuss the role of the thick ascending limb in the development of hypertension, not as a sole participant, but one that works within the rich biological context of the renal medulla. We first provide an overview of the basic physiology of the segment and the anatomical considerations necessary to understand its relationship with other renal structures. We explore the physiopathological changes in thick ascending limbs occurring in both genetic and induced animal models of hypertension. We then discuss the racial differences and genetic defects that affect blood pressure in humans through changes in thick ascending limb transport rates. Throughout the text, we scrutinize methodologies and discuss the limitations of research techniques that, when overlooked, can lead investigators to make erroneous conclusions. Thus, in addition to advancing an understanding of the basic mechanisms of physiology, the ultimate goal of this work is to understand our research tools, to make better use of them, and to contextualize research data. Future advances in renal hypertension research will require not only collection of new experimental data, but also integration of our current knowledge.
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Affiliation(s)
| | - Fara Saez
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Casandra M Monzon
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jessica Asirwatham
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jeffrey L Garvin
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
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7
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Singh S, Sharma R, Kumari M, Tiwari S. Insulin receptors in the kidneys in health and disease. World J Nephrol 2019; 8:11-22. [PMID: 30705868 PMCID: PMC6354081 DOI: 10.5527/wjn.v8.i1.11] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/15/2018] [Accepted: 12/10/2018] [Indexed: 02/06/2023] Open
Abstract
Insulin is an important hormone that affects various metabolic processes, including kidney function. Impairment in insulin’s action leads to insulin resistance in the target tissue. Besides defects in post-receptor insulin signaling, impairment at the receptor level could significantly affect insulin sensitivity of the target tissue. The kidney is a known target of insulin; however, whether the kidney develops “insulin resistance” is debatable. Regulation of the insulin receptor (IR) expression and its function is very well studied in major metabolic tissues like liver, skeletal muscles, and adipose tissue. The physiological relevance of IRs in the kidney has recently begun to be clarified. The credit goes to studies that showed a wide distribution of IR throughout the nephron segments and their reduced expression in the insulin resistance state. Moreover, altered renal and systemic metabolism observed in mice with targeted deletion of the IR from various epithelial cells of the kidney has strengthened this proposition. In this review, we recapitulate the crucial findings from literature that have expanded our knowledge regarding the significance of the renal IR in normal- and insulin-resistance states.
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Affiliation(s)
- Sarojini Singh
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Rajni Sharma
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Manju Kumari
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Swasti Tiwari
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
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8
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Trepiccione F, Soukaseum C, Baudrie V, Kumai Y, Teulon J, Villoutreix B, Cornière N, Wangemann P, Griffith AJ, Byung Choi Y, Hadchouel J, Chambrey R, Eladari D. Acute genetic ablation of pendrin lowers blood pressure in mice. Nephrol Dial Transplant 2018; 32:1137-1145. [PMID: 28064162 DOI: 10.1093/ndt/gfw393] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/02/2016] [Indexed: 11/14/2022] Open
Abstract
Background Pendrin, the chloride/bicarbonate exchanger of β-intercalated cells of the renal connecting tubule and the collecting duct, plays a key role in NaCl reabsorption by the distal nephron. Therefore, pendrin may be important for the control of extracellular fluid volume and blood pressure. Methods Here, we have used a genetic mouse model in which the expression of pendrin can be switched-on in vivo by the administration of doxycycline. Pendrin can also be rapidly removed when doxycycline administration is discontinued. Therefore, our genetic strategy allows us to test selectively the acute effects of loss of pendrin function. Results We show that acute loss of pendrin leads to a significant decrease of blood pressure. In addition, acute ablation of pendrin did not alter significantly the acid-base status or blood K + concentration. Conclusion By using a transgenic mouse model, avoiding off-target effects related to pharmacological compounds, this study suggests that pendrin could be a novel target to treat hypertension.
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Affiliation(s)
- Francesco Trepiccione
- INSERM U970, Paris Cardiovascular Research Center, Université Paris-Descartes, Paris, France
| | - Christelle Soukaseum
- INSERM U970, Paris Cardiovascular Research Center, Université Paris-Descartes, Paris, France
| | - Veronique Baudrie
- INSERM U970, Paris Cardiovascular Research Center, Université Paris-Descartes, Paris, France.,Hôpital Européen Georges Pompidou, Département de Physiologie, Assistance Publique-Hopitaux de Paris, Paris, France
| | - Yusuke Kumai
- INSERM U970, Paris Cardiovascular Research Center, Université Paris-Descartes, Paris, France
| | - Jacques Teulon
- CNRS ERL 8228, INSERM UMRS 1138, Université Pierre et Marie Curie, Centre de Recherche des Cordeliers, Paris, France
| | - Bruno Villoutreix
- INSERM U973, MTi-Bioinformatics; University Paris Diderot, Paris, France
| | - Nicolas Cornière
- Service d'Explorations Fonctionnelles Rénales, Hôpital Felix Guyon, CHU de la Réunion, St Denis, Ile de la Réunion, France
| | - Philine Wangemann
- Anatomy and Physiology Department, Kansas State University, Manhattan, KS, USA
| | - Andrew J Griffith
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Yoon Byung Choi
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Juliette Hadchouel
- INSERM U970, Paris Cardiovascular Research Center, Université Paris-Descartes, Paris, France
| | - Regine Chambrey
- INSERM U970, Paris Cardiovascular Research Center, Université Paris-Descartes, Paris, France.,Centre National de la Recherche Scientifique, Paris, France
| | - Dominique Eladari
- Service d'Explorations Fonctionnelles Rénales, Hôpital Felix Guyon, CHU de la Réunion, St Denis, Ile de la Réunion, France
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9
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Caterino M, Zacchia M, Costanzo M, Bruno G, Arcaniolo D, Trepiccione F, Siciliano R, Mazzeo M, Ruoppolo M, Capasso G. Urine Proteomics Revealed a Significant Correlation Between Urine-Fibronectin Abundance and Estimated-GFR Decline in Patients with Bardet-Biedl Syndrome. Kidney Blood Press Res 2018. [DOI: 10.1159/000488096] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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10
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Zacchia M, Capolongo G, Rinaldi L, Capasso G. The importance of the thick ascending limb of Henle's loop in renal physiology and pathophysiology. Int J Nephrol Renovasc Dis 2018; 11:81-92. [PMID: 29497325 PMCID: PMC5818843 DOI: 10.2147/ijnrd.s154000] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The thick ascending limb (TAL) of Henle’s loop is a crucial segment for many tasks of the nephron. Indeed, the TAL is not only a mainstay for reabsorption of sodium (Na+), potassium (K+), and divalent cations such as calcium (Ca2+) and magnesium (Mg2+) from the luminal fluid, but also has an important role in urine concentration, overall acid–base homeostasis, and ammonia cycle. Transcellular Na+ transport along the TAL is a prerequisite for Na+, K+, Ca2+, Mg2+ homeostasis, and water reabsorption, the latter through its contribution in the generation of the cortico-medullar osmotic gradient. The role of this nephron site in acid–base balance, via bicarbonate reabsorption and acid secretion, is sometimes misunderstood by clinicians. This review describes in detail these functions, reporting in addition to the well-known molecular mechanisms, some novel findings from the current literature; moreover, the pathophysiology and the clinical relevance of primary or acquired conditions caused by TAL dysfunction are discussed. Knowing the physiology of the TAL is fundamental for clinicians, for a better understanding and management of rare and common conditions, such as tubulopathies, hypertension, and loop diuretics abuse.
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Affiliation(s)
- Miriam Zacchia
- Division of Nephrology, Department of Cardio-Thoracic and Respiratory Sciences, Università della Campania "Luigi Vanvitelli", Naples, Italy
| | - Giovanna Capolongo
- Division of Nephrology, Department of Cardio-Thoracic and Respiratory Sciences, Università della Campania "Luigi Vanvitelli", Naples, Italy
| | - Luca Rinaldi
- Division of Nephrology, Department of Cardio-Thoracic and Respiratory Sciences, Università della Campania "Luigi Vanvitelli", Naples, Italy
| | - Giovambattista Capasso
- Division of Nephrology, Department of Cardio-Thoracic and Respiratory Sciences, Università della Campania "Luigi Vanvitelli", Naples, Italy
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11
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Zacchia M, Capolongo G, Trepiccione F, Marion V. Impact of Local and Systemic Factors on Kidney Dysfunction in Bardet-Biedl Syndrome. Kidney Blood Press Res 2017; 42:784-793. [PMID: 29161709 DOI: 10.1159/000484301] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 10/01/2017] [Indexed: 11/19/2022] Open
Abstract
Bardet Biedl syndrome (BBS) is a rare inherited syndromic condition characterized by renal and extra-renal disorders. Renal defect, at either structural or functional level, is one of the cardinal clinical features, and is a major cause of morbidity. However, the pathogenic mechanism underlying its dysfunction remains largely unknown, and to date only symptomatic treatment with no specific therapy is available for these patients. Elucidating aberrant cellular and/or systemic processes that impact kidney function is therefore a prerequisite to develop targeted innovative therapeutic strategies for the BBS patients. Given the proven role of BBS proteins in the function of the primary cilium (PC) and considering the clinical overlapping of BBS with other ciliopathies, BBS is considered the result of disruption of ciliary activities. The present review aims at giving an updated overview of the spectrum of renal abnormalities in BBS patients according to the existing scientific literature, and discusses the possible role of intrinsic PC dysfunction into the pathogenesis of renal defects based on the most recent findings demonstrating a possible role of systemic factors in favoring the progression of renal disease.
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Affiliation(s)
- Miriam Zacchia
- Division of Nephrology, Department of Cardio-Thoracic and Respiratory Sciences, Università della Campania "Luigi Vanvitelli", Naples, Italy
| | - Giovanna Capolongo
- Division of Nephrology, Department of Cardio-Thoracic and Respiratory Sciences, Università della Campania "Luigi Vanvitelli", Naples, Italy
| | - Francesco Trepiccione
- Division of Nephrology, Department of Cardio-Thoracic and Respiratory Sciences, Università della Campania "Luigi Vanvitelli", Naples, Italy
| | - Vincent Marion
- INSERM, U1112, Laboratoire de Génétique Médicale , Ciliopathies modeling and associated therapies team, Faculté de Medecine, Strasbroug Cedex, France
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12
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Simeoni M, Damiano S, Capolongo G, Trepiccione F, Zacchia M, Fuiano G, Capasso G. Rare Renal Diseases Can Be Used as Tools to Investigate Common Kidney Disorders. KIDNEY DISEASES (BASEL, SWITZERLAND) 2017; 3:43-49. [PMID: 28868291 PMCID: PMC5566759 DOI: 10.1159/000475841] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 04/15/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND The prevention and slowing of chronic kidney disease still represent major challenges in nephrology. To this end, a major contribution may come from the extensive knowledge on the molecular pathways involved in the pathogenesis of rare kidney diseases, since it is now possible to shed light on several aspects of these pathologies thanks to the introduction of new technologies, including next-generation sequencing. SUMMARY In steroid-resistant nephrotic patients, a genetic background has been demonstrated in both children and adults; individualized mutations have been correlated with glomerular filtration barrier alterations. In addition, studies on genetic tubulopathies expressing hypertensive phenotypes can provide useful information for a correct diagnostic and therapeutic approach in patients with essential hypertension and a poor responsiveness to therapy. KEY MESSAGE This review deals with the pathogenesis of rare glomerular diseases and tubulopathies associated with hypertension, highlighting the importance of the study of rare diseases to better understand the molecular basis of more common and complex disorders leading to end-stage renal disease.
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Affiliation(s)
- Mariadelina Simeoni
- Department of Nephrology, Magna Graecia University Hospital, Catanzaro, Italy
| | - Sara Damiano
- Department of Nephrology, University of Campania “Luigi Vanvitelli,” Naples, Italy
| | - Giovanna Capolongo
- Department of Nephrology, University of Campania “Luigi Vanvitelli,” Naples, Italy
| | | | - Miriam Zacchia
- Department of Nephrology, University of Campania “Luigi Vanvitelli,” Naples, Italy
| | - Giorgio Fuiano
- Department of Nephrology, Magna Graecia University Hospital, Catanzaro, Italy
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13
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Layton AT, Laghmani K, Vallon V, Edwards A. Solute transport and oxygen consumption along the nephrons: effects of Na+ transport inhibitors. Am J Physiol Renal Physiol 2016; 311:F1217-F1229. [PMID: 27707706 DOI: 10.1152/ajprenal.00294.2016] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/28/2016] [Indexed: 01/11/2023] Open
Abstract
Sodium and its associated anions are the major determinant of extracellular fluid volume, and the reabsorption of Na+ by the kidney plays a crucial role in long-term blood pressure control. The goal of this study was to investigate the extent to which inhibitors of transepithelial Na+ transport (TNa) along the nephron alter urinary solute excretion and TNa efficiency and how those effects may vary along different nephron segments. To accomplish that goal, we used the multinephron model developed in the companion study (28). That model represents detailed transcellular and paracellular transport processes along the nephrons of a rat kidney. We simulated the inhibition of the Na+/H+ exchanger (NHE3), the bumetanide-sensitive Na+-K+-2Cl- transporter (NKCC2), the Na+-Cl- cotransporter (NCC), and the amiloride-sensitive Na+ channel (ENaC). Under baseline conditions, NHE3, NKCC2, NCC, and ENaC reabsorb 36, 22, 4, and 7%, respectively, of filtered Na+ The model predicted that inhibition of NHE3 substantially reduced proximal tubule TNa and oxygen consumption (QO2 ). Whole-kidney TNa efficiency, as reflected by the number of moles of Na+ reabsorbed per moles of O2 consumed (denoted by the ratio TNa/QO2 ), decreased by ∼20% with 80% inhibition of NHE3. NKCC2 inhibition simulations predicted a substantial reduction in thick ascending limb TNa and QO2 ; however, the effect on whole-kidney TNa/QO2 was minor. Tubular K+ transport was also substantially impaired, resulting in elevated urinary K+ excretion. The most notable effect of NCC inhibition was to increase the excretion of Na+, K+, and Cl-; its impact on whole-kidney TNa and its efficiency was minor. Inhibition of ENaC was predicted to have opposite effects on the excretion of Na+ (increased) and K+ (decreased) and to have only a minor impact on whole-kidney TNa and TNa/QO2 Overall, model predictions agree well with measured changes in Na+ and K+ excretion in response to diuretics and Na+ transporter mutations.
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Affiliation(s)
- Anita T Layton
- Department of Mathematics, Duke University, Durham, North Carolina;
| | - Kamel Laghmani
- 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
| | - Volker Vallon
- Departments of Medicine and Pharmacology, University of California San Diego, La Jolla, California, and San Diego Veterans Affairs Healthcare System, San Diego, California
| | - 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
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14
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Luan H, Wu P, Wang M, Sui H, Fan L, Gu R. Effects of adenosine stimulation on the mRNA expression of CLCNKB in the basolateral medullary thick ascending limb of the rat kidney. Mol Med Rep 2016; 14:4391-4398. [PMID: 27748841 DOI: 10.3892/mmr.2016.5781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 08/06/2016] [Indexed: 11/06/2022] Open
Abstract
Adenosine is a molecule produced by several organs within the body, including the kidneys, where it acts as an autoregulatory factor. It mediates ion transport in several nephron segments, including the proximal tubule and the thick ascending limb (TAL). Ion transport is dictated in part by anionic chloride channels, which regulate crucial kidney functions, including the reabsorption of Na+ and Cl‑, urine concentration, and establishing and maintaining the corticomedullary osmotic gradient. The present study investigated the effects of adenosine on the mRNA expression of chloride voltage‑gated channel Kb (CLCNKB), a candidate gene involved in hypertension, which encodes for the ClC‑Kb channel. Medullary thick ascending limb (mTAL) tubules were isolated from the rat kidney, and primary cultures of mTAL cells from the mTAL tubules were established. The cells were treated with adenosine and the mRNA expression of CLCNKB was detected by reverse transcription‑quantitative polymerase chain reaction. The cells were also treated with pathways inhibitors (H8 and AACOCF3), and the protein expression of cyclic adenosine 3',5'‑monophosphate (cAMP)‑protein kinase A (PKA) and phospholipase A2 (PLA2) by were analyzed by western blotting. The findings indicated that adenosine increased the mRNA expression of CLCNKB in primary cultures of medullary TAL cells, and this stimulatory effect was regulated by the cAMP‑PKA and PLA2‑arachidonic acid (AA) pathways. The present study showed that adenosine affected the mRNA expression of CLCNKB, initially through the cAMP‑PKA pathway and then the PLA2‑AA pathway.
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Affiliation(s)
- Haiyan Luan
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Peng Wu
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Mingxiao Wang
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Hongyu Sui
- Department of Physiology, Basic Medical School, Jiamusi University, Jiamusi, Heilongjiang 154007, P.R. China
| | - Lili Fan
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Ruimin Gu
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
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15
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Abstract
During the past 20 years, the studies on genetics or pharmacogenomics of primary hypertension provided interesting results supporting the role of genetics, but no actionable finding ready to be translated into personalized medicine. Two types of approaches have been applied: a "hypothesis-driven" approach on the candidate genes, coding for proteins involved in the biochemical machinery underlying the regulation of BP, and an "unbiased hypothesis-free" approach with GWAS, based on the randomness principles of frequentist statistics. During the past 10-15 years, the application of the latter has overtaken the application of the former leading to an enlargement of the number of previously unknown candidate loci or genes but without any actionable result for the therapy of hypertension. In the present review, we summarize the results of our hypothesis-driven approach based on studies carried out in rats with genetic hypertension and in humans with essential hypertension at the pre-hypertensive and early hypertensive stages. These studies led to the identification of mutant adducin and endogenous ouabain as candidate genetic-molecular mechanisms in both species. Rostafuroxin has been developed for its ability to selectively correct Na(+) pump abnormalities sustained by the two abovementioned mechanisms and to selectively reduce BP in rats and in humans carrying the gene variants underlying the mutant adducin and endogenous ouabain (EO) effects. A clinical trial is ongoing to substantiate these findings. Future studies should apply both the candidate gene and GWAS approaches to fully exploit the potential of genetics in optimizing the personalized therapy.
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16
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Zaika O, Tomilin V, Mamenko M, Bhalla V, Pochynyuk O. New perspective of ClC-Kb/2 Cl- channel physiology in the distal renal tubule. Am J Physiol Renal Physiol 2016; 310:F923-30. [PMID: 26792067 PMCID: PMC5002062 DOI: 10.1152/ajprenal.00577.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 01/14/2016] [Indexed: 12/17/2022] Open
Abstract
Since its identification as the underlying molecular cause of Bartter's syndrome type 3, ClC-Kb (ClC-K2 in rodents, henceforth it will be referred as ClC-Kb/2) is proposed to play an important role in systemic electrolyte balance and blood pressure regulation by controlling basolateral Cl(-) exit in the distal renal tubular segments from the cortical thick ascending limb to the outer medullary collecting duct. Considerable experimental and clinical effort has been devoted to the identification and characterization of disease-causing mutations as well as control of the channel by its cofactor, barttin. However, we have only begun to unravel the role of ClC-Kb/2 in different tubular segments and to reveal the regulators of its expression and function, e.g., insulin and IGF-1. In this review we discuss recent experimental evidence in this regard and highlight unexplored questions critical to understanding ClC-Kb/2 physiology in the kidney.
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Affiliation(s)
- Oleg Zaika
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, Texas; and
| | - Viktor Tomilin
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, Texas; and
| | - Mykola Mamenko
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, Texas; and
| | - Vivek Bhalla
- Division of Nephrology, Department of Medicine, Stanford University, Stanford, California
| | - Oleh Pochynyuk
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, Texas; and
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17
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18
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Lupoli S, Salvi E, Barcella M, Barlassina C. Pharmacogenomics considerations in the control of hypertension. Pharmacogenomics 2015; 16:1951-64. [PMID: 26555875 DOI: 10.2217/pgs.15.131] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The response to antihypertensive therapy is very heterogeneous and the need by the physicians to account for it has driven much interest in pharmacogenomics of antihypertensive drugs. The Human Genome Project and the initiatives in genomics that followed, generated a huge number of genetic data that furnished the tools to explore the genotype-phenotype association in candidate genes and at genome-wide level. In spite of the efforts and the great number of publications, pharmacogenomics of antihypertensive drugs is far from being used in clinical practice. In this review, we analyze the main findings available in PubMed from 2010 to 2015, in relation to the major classes of antihypertensive drugs. We also describe a new Phase II drug that targets two specific hypertension predisposing mechanisms.
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Affiliation(s)
- Sara Lupoli
- Department of Health Sciences, Milan University, Via Rudinì 8, 20142 Milan & Filarete Foundation, Viale Ortles 22/4, 20139 Milan, Italy
| | - Erika Salvi
- Department of Health Sciences, Milan University, Via Rudinì 8, 20142 Milan & Filarete Foundation, Viale Ortles 22/4, 20139 Milan, Italy
| | - Matteo Barcella
- Department of Health Sciences, Milan University, Via Rudinì 8, 20142 Milan & Filarete Foundation, Viale Ortles 22/4, 20139 Milan, Italy
| | - Cristina Barlassina
- Department of Health Sciences, Milan University, Via Rudinì 8, 20142 Milan & Filarete Foundation, Viale Ortles 22/4, 20139 Milan, Italy
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19
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Nishimoto M, Fujita T. Renal mechanisms of salt-sensitive hypertension: contribution of two steroid receptor-associated pathways. Am J Physiol Renal Physiol 2015; 308:F377-87. [DOI: 10.1152/ajprenal.00477.2013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Although salt is a major environmental factor in the development of hypertension, the degree of salt sensitivity varies widely among individuals. The mechanisms responsible for this variation remain to be elucidated. Recent studies have revealed the involvement of two important signaling pathways in renal tubules that play key roles in electrolyte balance and the maintenance of normal blood pressure: the β2-adrenergic stimulant-glucocorticoid receptor (GR)-with-no-lysine kinase (WNK)4-Na+-Cl− cotransporter pathway, which is active in distal convoluted tubule (DCT)1, and the Ras-related C3 botulinum toxin substrate (Rac)1-mineralocorticoid receptor (MR) pathway, which is active in DCT2, connecting tubules, and collecting ducts. β2-Adrenergic stimulation due to increased renal sympathetic activity in obesity- and salt-induced hypertension suppresses histone deacetylase 8 activity via cAMP/PKA signaling, increasing the accessibility of GRs to the negative GR response element in the WNK4 promoter. This results in the suppression of WNK4 transcription followed by the activation of Na+-Cl− cotransporters in the DCT and elevated Na+ retention and blood pressure upon salt loading. Rac1 activates MRs, even in the absence of ligand binding, with this activity increased in the presence of ligand. In salt-sensitive animals, Rac1 activation due to salt loading activates MRs in DCT2, connecting tubules, and collecting ducts. Thus, GRs and MRs are independently involved in two pathways responsible for renal Na+ handling and salt-sensitive hypertension. These findings suggest novel therapeutic targets and may lead to the development of diagnostic tools to determine salt sensitivity in hypertensive patients.
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Affiliation(s)
- Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
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20
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The hidden hand of chloride in hypertension. Pflugers Arch 2015; 467:595-603. [PMID: 25619794 PMCID: PMC4325190 DOI: 10.1007/s00424-015-1690-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/03/2014] [Accepted: 12/05/2014] [Indexed: 01/10/2023]
Abstract
Among the environmental factors that affect blood pressure, dietary sodium chloride has been studied the most, and there is general consensus that increased sodium chloride intake increases blood pressure. There is accruing evidence that chloride may have a role in blood pressure regulation which may perhaps be even more important than that of Na+. Though more than 85 % of Na+ is consumed as sodium chloride, there is evidence that Na+ and Cl− concentrations do not go necessarily hand in hand since they may originate from different sources. Hence, elucidating the role of Cl− as an independent player in blood pressure regulation will have clinical and public health implications in addition to advancing our understanding of electrolyte-mediated blood pressure regulation. In this review, we describe the evidence that support an independent role for Cl− on hypertension and cardiovascular health.
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21
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Matafora V, Zagato L, Ferrandi M, Molinari I, Zerbini G, Casamassima N, Lanzani C, Delli Carpini S, Trepiccione F, Manunta P, Bachi A, Capasso G. Quantitative proteomics reveals novel therapeutic and diagnostic markers in hypertension. BBA CLINICAL 2014; 2:79-87. [PMID: 26672470 PMCID: PMC4633972 DOI: 10.1016/j.bbacli.2014.10.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 10/01/2014] [Accepted: 10/06/2014] [Indexed: 01/13/2023]
Abstract
Hypertension is a prevalent disorder in the world representing one of the major risk factors for heart attack and stroke. These risks are increased in salt sensitive individuals. Hypertension and salt sensitivity are complex phenotypes whose pathophysiology remains poorly understood and, remarkably, salt sensitivity is still laborious to diagnose. Here we present a urinary proteomic study specifically designed to identify urinary proteins relevant for the pathogenesis of hypertension and salt sensitivity. Despite previous studies that underlined the association of UMOD gene variants with hypertension, this work provides novel evidence showing different uromodulin protein level in the urine of hypertensive patients compared to healthy individuals. Notably, we also show that patients with higher level of uromodulin are homozygous for UMOD risk variant and display a decreased level of salt excretion, highlighting the essential role of UMOD in the regulation of salt reabsorption in hypertension. Additionally, we found that urinary nephrin 1, a marker of glomerular slit diaphragm, may predict a salt sensitive phenotype and positively correlate with increased albuminuria associated with this type of hypertension. We identified urinary proteins differently excreted in hypertensive patients. Nephrin 1 might predict salt sensitive phenotype and glomerular complications. Uromodulin impacts salt homeostasis in hypertension. We provide new insights into the pathogenesis of hypertension and salt sensitivity.
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Key Words
- BMI, body mass index
- BP, blood pressure
- DBP, diastolic BP
- GO, Gene Ontology
- Glomerular injury
- LC–MS/MS, liquid chromatography coupled to tandem mass spectrometry
- MBP, mean BP.
- MQ, MaxQuant
- Nephrinuria
- Quantitative proteomics
- SBP, systolic BP
- SR, salt resistant
- SS, salt sensitive
- Salt homeostasis
- Salt sensitive hypertension
- Urinary biomarker
- Uromodulin
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Affiliation(s)
- Vittoria Matafora
- IFOM-FIRC Institute of Molecular Oncology, Milan, Italy ; Chair of Nephrology, Department of Cardio-Vascular Medicine, Second University of Naples, Naples, Italy
| | - Laura Zagato
- Genomics of Renal Diseases and Hypertension Unit, Division of Genetics & Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Mara Ferrandi
- Genomics of Renal Diseases and Hypertension Unit, Division of Genetics & Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Isabella Molinari
- Genomics of Renal Diseases and Hypertension Unit, Division of Genetics & Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Gianpaolo Zerbini
- Division of Metabolic and Cardiovascular Sciences, San Raffaele Scientific Institute, Milan, Italy
| | - Nunzia Casamassima
- Genomics of Renal Diseases and Hypertension Unit, Division of Genetics & Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Chiara Lanzani
- Genomics of Renal Diseases and Hypertension Unit, Division of Genetics & Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Simona Delli Carpini
- Genomics of Renal Diseases and Hypertension Unit, Division of Genetics & Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Francesco Trepiccione
- Chair of Nephrology, Department of Cardio-Vascular Medicine, Second University of Naples, Naples, Italy
| | - Paolo Manunta
- Genomics of Renal Diseases and Hypertension Unit, Division of Genetics & Cell Biology, San Raffaele Scientific Institute, Milan, Italy ; Chair of Nephrology, University Vita-Salute San Raffaele, Milan, Italy
| | - Angela Bachi
- IFOM-FIRC Institute of Molecular Oncology, Milan, Italy
| | - Giovambattista Capasso
- Chair of Nephrology, Department of Cardio-Vascular Medicine, Second University of Naples, Naples, Italy
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22
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Stauber T, Weinert S, Jentsch TJ. Cell biology and physiology of CLC chloride channels and transporters. Compr Physiol 2013; 2:1701-44. [PMID: 23723021 DOI: 10.1002/cphy.c110038] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Proteins of the CLC gene family assemble to homo- or sometimes heterodimers and either function as Cl(-) channels or as Cl(-)/H(+)-exchangers. CLC proteins are present in all phyla. Detailed structural information is available from crystal structures of bacterial and algal CLCs. Mammals express nine CLC genes, four of which encode Cl(-) channels and five 2Cl(-)/H(+)-exchangers. Two accessory β-subunits are known: (1) barttin and (2) Ostm1. ClC-Ka and ClC-Kb Cl(-) channels need barttin, whereas Ostm1 is required for the function of the lysosomal ClC-7 2Cl(-)/H(+)-exchanger. ClC-1, -2, -Ka and -Kb Cl(-) channels reside in the plasma membrane and function in the control of electrical excitability of muscles or neurons, in extra- and intracellular ion homeostasis, and in transepithelial transport. The mainly endosomal/lysosomal Cl(-)/H(+)-exchangers ClC-3 to ClC-7 may facilitate vesicular acidification by shunting currents of proton pumps and increase vesicular Cl(-) concentration. ClC-3 is also present on synaptic vesicles, whereas ClC-4 and -5 can reach the plasma membrane to some extent. ClC-7/Ostm1 is coinserted with the vesicular H(+)-ATPase into the acid-secreting ruffled border membrane of osteoclasts. Mice or humans lacking ClC-7 or Ostm1 display osteopetrosis and lysosomal storage disease. Disruption of the endosomal ClC-5 Cl(-)/H(+)-exchanger leads to proteinuria and Dent's disease. Mouse models in which ClC-5 or ClC-7 is converted to uncoupled Cl(-) conductors suggest an important role of vesicular Cl(-) accumulation in these pathologies. The important functions of CLC Cl(-) channels were also revealed by human diseases and mouse models, with phenotypes including myotonia, renal loss of salt and water, deafness, blindness, leukodystrophy, and male infertility.
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Affiliation(s)
- Tobias Stauber
- Leibniz-Institut für Molekulare Pharmakologie FMP and Max-Delbrück-Centrum für Molekulare Medizin MDC, Berlin, Germany
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23
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Richardson SI, Freedman BI, Ellison DH, Rodriguez CJ. Salt sensitivity: a review with a focus on non-Hispanic blacks and Hispanics. JOURNAL OF THE AMERICAN SOCIETY OF HYPERTENSION : JASH 2013; 7:170-9. [PMID: 23428408 PMCID: PMC4574876 DOI: 10.1016/j.jash.2013.01.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 01/08/2013] [Accepted: 01/11/2013] [Indexed: 01/07/2023]
Abstract
The purpose of this review is to summarize the available information regarding salt sensitivity particularly as it relates to non-Hispanic blacks and Hispanics and to clarify possible etiologies, especially those that might shed light on potential treatment options. In non-Hispanic blacks, there is evidence that endothelial dysfunction, reduced potassium intake, decreased urinary kallikrein excretion, upregulation of sodium channel activity, dysfunction in atrial natriuretic peptide (ANP) production, and APOL1 gene nephropathy risk variants may cause or contribute to salt sensitivity. Supported treatment avenues include diets high in potassium and soybean protein, the components of which stimulate nitric oxide production. Racial heterogeneity complicates the study of salt sensitivity in Hispanic populations. Caribbean Hispanics, who have a higher proportion of African ancestry, may respond to commonly prescribed anti-hypertensive agents in a way that is characteristic of non-Hispanic black hypertensives. The low-renin hypertensive phenotype commonly seen in non-Hispanic blacks has been linked to salt sensitivity and may indicate an increased risk for salt sensitivity in a portion of the Hispanic population. In conclusion, increased morbidity and mortality associated with salt sensitivity mandates further studies evaluating the efficacy of tailored dietary and pharmacologic treatment in non-Hispanic blacks and determining the prevalence of low renin hypertension and salt sensitivity within the various subgroups of Hispanic Americans.
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Affiliation(s)
| | - Barry I. Freedman
- Department of Medicine, Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - David H. Ellison
- Division of Nephrology and Hypertension, Oregon Health & Science University, Portland, OR, USA
| | - Carlos J. Rodriguez
- Department of Medicine and Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA
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24
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Mondini A, Sassone F, Civello DA, Garavaglia ML, Bazzini C, Rodighiero S, Vezzoli V, Conti F, Torielli L, Capasso G, Paulmichl M, Meyer G. Hypertension-linked mutation of α-adducin increases CFTR surface expression and activity in HEK and cultured rat distal convoluted tubule cells. PLoS One 2012; 7:e52014. [PMID: 23284854 PMCID: PMC3528715 DOI: 10.1371/journal.pone.0052014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 11/08/2012] [Indexed: 11/18/2022] Open
Abstract
The CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) activity and localization are influenced by the cytoskeleton, in particular by actin and its polymerization state. In this study we investigated whether the expression of the hypertensive mutations of α-adducin (G460W-S586C in humans, F316Y in rats), an actin capping protein, led to a functional modification of CFTR activity and surface expression. The experiments were performed on HEK293 T cells cotransfected with CFTR and the human wild type (WT) or G460W mutated α-adducin. In whole-cell patch-clamp experiments, both the CFTR chloride current and the slope of current activation after forskolin addition were significantly higher in HEK cells overexpressing the G460W adducin. A higher plasma membrane density of active CFTR channels was confirmed by cell-attached patch-clamp experiments, both in HEK cells and in cultured primary DCT cells, isolated from MHS (Milan Hypertensive Strain, a Wistar rat (Rattus norvegicus) hypertensive model carrying the F316Y adducin mutation), compared to MNS (Milan Normotensive Strain) rats. Western blot experiments demonstrated an increase of the plasma membrane CFTR protein expression, with a modification of the channel glycosylation state, in the presence of the mutated adducin. A higher retention of CFTR protein in the plasma membrane was confirmed both by FRAP (Fluorescence Recovery After Photobleaching) and photoactivation experiments. The present data indicate that in HEK cells and in isolated DCT cells the presence of the G460W-S586C hypertensive variant of adducin increases CFTR channel activity, possibly by altering its membrane turnover and inducing a retention of the channel in the plasmamembrane. Since CFTR is known to modulate the activity of many others transport systems, the increased surface expression of the channel could have consequences on the whole network of transport in kidney cells.
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Affiliation(s)
- Anna Mondini
- Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
| | - Francesca Sassone
- Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
| | | | | | - Claudia Bazzini
- Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
| | | | - Valeria Vezzoli
- Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
| | - Fabio Conti
- Prassis Research Institute, Sigma Tau, Settimo M.se, Italy
| | - Lucia Torielli
- Prassis Research Institute, Sigma Tau, Settimo M.se, Italy
| | | | - Markus Paulmichl
- Institut of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
| | - Giuliano Meyer
- Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
- * E-mail:
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25
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Markadieu N, San-Cristobal P, Nair AV, Verkaart S, Lenssen E, Tudpor K, van Zeeland F, Loffing J, Bindels RJM, Hoenderop JGJ. A primary culture of distal convoluted tubules expressing functional thiazide-sensitive NaCl transport. Am J Physiol Renal Physiol 2012; 303:F886-92. [PMID: 22759396 DOI: 10.1152/ajprenal.00114.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Studying the molecular regulation of the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC) is important for understanding how the kidney contributes to blood pressure regulation. Until now, a native mammalian cell model to investigate this transporter remained unknown. Our aim here is to establish, for the first time, a primary distal convoluted tubule (DCT) cell culture exhibiting transcellular thiazide-sensitive Na(+) transport. Because parvalbumin (PV) is primarily expressed in the DCT, where it colocalizes with NCC, kidneys from mice expressing enhanced green-fluorescent protein (eGFP) under the PV gene promoter (PV-eGFP-mice) were employed. The Complex Object Parametric Analyzer and Sorter (COPAS) was used to sort fluorescent PV-positive tubules from these kidneys, which were then seeded onto permeable supports. After 6 days, DCT cell monolayers developed transepithelial resistance values of 630 ± 33 Ω·cm(2). The monolayers also established opposing transcellular concentration gradients of Na(+) and K(+). Radioactive (22)Na(+) flux experiments showed a net apical-to-basolateral thiazide-sensitive Na(+) transport across the monolayers. Both hypotonic low-chloride medium and 1 μM angiotensin II increased this (22)Na(+) transport significantly by four times, which could be totally blocked by 100 μM hydrochlorothiazide. Angiotensin II-stimulated (22)Na(+) transport was also inhibited by 1 μM losartan. Furthermore, NCC present in the DCT monolayers was detected by immunoblot and immunocytochemistry studies. In conclusion, a murine primary DCT culture was established which expresses functional thiazide-sensitive Na(+)-Cl(-) transport.
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Affiliation(s)
- Nicolas Markadieu
- Department of Physiology, Radboud University Nijmegen Medical Centre, The Netherlands
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Girardi ACC, Di Sole F. Deciphering the mechanisms of the Na+/H+ exchanger-3 regulation in organ dysfunction. Am J Physiol Cell Physiol 2012; 302:C1569-87. [DOI: 10.1152/ajpcell.00017.2012] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The Na+/H+ exchanger-3 (NHE3) belongs to the mammalian NHE protein family and catalyzes the electro-neutral exchange of extracellular sodium for intracellular proton across cellular membranes. Its transport function is of essential importance for the maintenance of the body's salt and water homeostasis as well as acid-base balance. Indeed, NHE3 activity is finely regulated by a variety of stimuli, both acutely and chronically, and its transport function is fundamental for a multiplicity of severe and world-wide infection-pathological conditions. This review aims to provide a concise overview of NHE3 physiology and discusses the role of NHE3 in clinical conditions of prominent importance, specifically in hypertension, diabetic nephropathy, heart failure, acute kidney injury, and diarrhea. Study of NHE3 function in models of these diseases has contributed to the deciphering of mechanisms that control the delicate ion balance disrupted in these disorders. The majority of the findings indicate that NHE3 transport function is activated before the onset of hypertension and inhibited thereafter; NHE3 transport function is also upregulated in diabetic nephropathy and heart failure, while it is reported to be downregulated in acute kidney injury and in diarrhea. The molecular mechanisms activated during these pathological conditions to regulate NHE3 transport function are examined with the aim of linking NHE3 dysfunction to the analyzed clinical disorders.
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Affiliation(s)
| | - Francesca Di Sole
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; and
- Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
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Citterio L, Lanzani C, Manunta P. Polymorphisms, hypertension and thiazide diuretics. Pharmacogenomics 2012; 12:1587-604. [PMID: 22044415 DOI: 10.2217/pgs.11.110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
It is 10 years since the discovery of the human genome; however, the study of the influence of genetic variants on drug effect - pharmacogenomics - has so far failed to create a major impact on day-to-day prescription practices. In the present article we analyze the main findings in candidate gene variants, gene combinations and whole-genome scans in relation to diuretic treatment. A critical analysis of the main reasons for some contrasting results will be discussed. The hypertension phases, in clinical trials dealing with genes and related pathophysiological mechanisms, may account for these inconsistent findings. The use of previously untreated versus treated patients is addressed. Finally, a positive study with a new genetic molecular strategy is described.
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Affiliation(s)
- Lorena Citterio
- San Raffaele Scientific Institute, OU of Nephrology & Dialysis, Università Vita-Salute, San Raffaele Hospital, Milan, Italy.
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Carmosino M, Procino G, Svelto M. Na+-K+-2Cl- cotransporter type 2 trafficking and activity: the role of interacting proteins. Biol Cell 2012; 104:201-12. [PMID: 22211456 DOI: 10.1111/boc.201100049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 12/28/2011] [Indexed: 11/30/2022]
Abstract
The central role of Na+-K+-2Cl- cotransporter type 2 (NKCC2) in vectorial transepithelial salt reabsorption in thick ascending limb cells from Henle's loop in the kidney is evidenced by the effects of loop diuretics, the pharmacological inhibitors of NKCC2, that are amongst the most powerful antihypertensive drugs available to date. Moreover, genetic mutations of the NKCC2 encoding gene resulting in impaired apical targeting and function of NKCC2 transporter give rise to a pathological phenotype known as type I Bartter syndrome, characterised by a severe volume depletion, hypokalaemia and metabolic alkalosis with high prenatal mortality. On the contrary, excessive NKCC2 activity has been linked with inherited hypertension in humans and in rodent models. Interestingly, in animal models of hypertension, NKCC2 upregulation is achieved by post-translational mechanisms underlining the need to analyse the molecular mechanisms involved in the regulation of NKCC2 trafficking and activity to gain insights in the pathogenesis of hypertension.
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Affiliation(s)
- Monica Carmosino
- Department of Biosciences, Biotechnologies and Pharmacological Sciences, University of Bari, Bari, Italy.
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Liantonio A, Gramegna G, Camerino GM, Dinardo MM, Scaramuzzi A, Potenza MA, Montagnani M, Procino G, Lasorsa DR, Mastrofrancesco L, Laghezza A, Fracchiolla G, Loiodice F, Perrone MG, Lopedota A, Conte S, Penza R, Valenti G, Svelto M, Camerino DC. In-vivo administration of CLC-K kidney chloride channels inhibitors increases water diuresis in rats. J Hypertens 2012; 30:153-67. [DOI: 10.1097/hjh.0b013e32834d9eb9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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30
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Linde CI, Karashima E, Raina H, Zulian A, Wier WG, Hamlyn JM, Ferrari P, Blaustein MP, Golovina VA. Increased arterial smooth muscle Ca2+ signaling, vasoconstriction, and myogenic reactivity in Milan hypertensive rats. Am J Physiol Heart Circ Physiol 2011; 302:H611-20. [PMID: 22140038 DOI: 10.1152/ajpheart.00950.2011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Milan hypertensive strain (MHS) rats are a genetic model of hypertension with adducin gene polymorphisms linked to enhanced renal tubular Na(+) reabsorption. Recently we demonstrated that Ca(2+) signaling is augmented in freshly isolated mesenteric artery myocytes from MHS rats. This is associated with greatly enhanced expression of Na(+)/Ca(2+) exchanger-1 (NCX1), C-type transient receptor potential (TRPC6) protein, and sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA2) compared with arteries from Milan normotensive strain (MNS) rats. Here, we test the hypothesis that the enhanced Ca(2+) signaling in MHS arterial smooth muscle is directly reflected in augmented vasoconstriction [myogenic and phenylephrine (PE)-evoked responses] in isolated mesenteric small arteries. Systolic blood pressure was higher in MHS (145 ± 1 mmHg) than in MNS (112 ± 1 mmHg; P < 0.001; n = 16 each) rats. Pressurized mesenteric resistance arteries from MHS rats had significantly augmented myogenic tone and reactivity and enhanced constriction to low-dose (1-100 nM) PE. Isolated MHS arterial myocytes exhibited approximately twofold increased peak Ca(2+) signals in response to 5 μM PE or ATP in the absence and presence of extracellular Ca(2+). These augmented responses are consistent with increased vasoconstrictor-evoked sarcoplasmic reticulum (SR) Ca(2+) release and increased Ca(2+) entry, respectively. The increased SR Ca(2+) release correlates with a doubling of inositol 1,4,5-trisphosphate receptor type 1 and tripling of SERCA2 expression. Pressurized MHS arteries also exhibited a ∼70% increase in 100 nM ouabain-induced vasoconstriction compared with MNS arteries. These functional alterations reveal that, in a genetic model of hypertension linked to renal dysfunction, multiple mechanisms within the arterial myocytes contribute to enhanced Ca(2+) signaling and myogenic and vasoconstrictor-induced arterial constriction. MHS rats have elevated plasma levels of endogenous ouabain, which may initiate the protein upregulation and enhanced Ca(2+) signaling. These molecular and functional changes provide a mechanism for the increased peripheral vascular resistance (whole body autoregulation) that underlies the sustained hypertension.
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Affiliation(s)
- Cristina I Linde
- Dept. of Physiology, Univ. of Maryland School of Medicine, 685 W. Baltimore St. HSF1, Rm. 565, Baltimore, MD 21201, USA
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31
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The role of the kidney in salt-sensitive hypertension. Clin Exp Nephrol 2011; 16:68-72. [PMID: 22038257 DOI: 10.1007/s10157-011-0489-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 04/22/2010] [Indexed: 10/16/2022]
Abstract
Primary hypertension is one of the leading risk factors for cardiovascular disease. Although the pathogenesis is not completely understood, an imbalance of sodium and chloride homeostasis seems to be relevant both in the induction and in the maintenance of salt-sensitive hypertension. Besides individual renal phenotypes, salt intake is one of the most important environmental determinants of this condition. The Milan hypertensive strain (MHS) of rats is an interesting model to investigate the molecular mechanisms underling the development of salt-sensitive hypertension. In young MHS rats, hypertension is anticipated by a phase of increased salt reabsorption localized along the medullary thick ascending limb associated with the up-regulation of the apical sodium-potassium-chloride cotransporter (NKCC2). Later, the frank hypertensive status of adult MHS rats is accompanied by the activation of the luminal and basal lateral transporters of sodium chloride (NaCl) in the distal convoluted tubule (DCT). Several lines of evidence have proven the key role of DCT in the maintenance of hypertension in MHS rats; more importantly, hypertensive patients carrying a mutation of α-adducin (resembling the MHS model) have a high sensitivity to thiazides, suggesting that the Na(+)-Cl(-) cotransporter also plays a pivotal role in humans.
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Kesteloot† H, Tzoulaki I, Brown IJ, Chan Q, Wijeyesekera A, Ueshima H, Zhao L, Dyer AR, Unwin RJ, Stamler J, Elliott P. Relation of urinary calcium and magnesium excretion to blood pressure: The International Study Of Macro- And Micro-nutrients And Blood Pressure and The International Cooperative Study On Salt, Other Factors, And Blood Pressure. Am J Epidemiol 2011; 174:44-51. [PMID: 21624957 PMCID: PMC3159430 DOI: 10.1093/aje/kwr049] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 02/03/2011] [Indexed: 11/12/2022] Open
Abstract
Data indicate an inverse association between dietary calcium and magnesium intakes and blood pressure (BP); however, much less is known about associations between urinary calcium and magnesium excretion and BP in general populations. The authors assessed the relation of BP to 24-hour excretion of calcium and magnesium in 2 cross-sectional studies. The International Study of Macro- and Micro-Nutrients and Blood Pressure (INTERMAP) comprised 4,679 persons aged 40-59 years from 17 population samples in China, Japan, the United Kingdom, and the United States, and the International Cooperative Study on Salt, Other Factors, and Blood Pressure (INTERSALT) comprised 10,067 persons aged 20-59 years from 52 samples around the world. Timed 24-hour urine collections, BP measurements, and nutrient data from four 24-hour dietary recalls (INTERMAP) were collected. In multiple linear regression analyses, urinary calcium excretion was directly associated with BP. After adjustment for multiple confounders (including weight, height, alcohol intake, calcium intake, urinary sodium level, and urinary potassium intake), systolic BP was 1.9 mm Hg higher per each 4.1 mmol per 24 hours (2 standard deviations) of higher urinary calcium excretion (associations were smaller for diastolic BP) in INTERMAP. Qualitatively similar associations were observed in INTERSALT analyses. Associations between magnesium excretion and BP were small and nonsignificant for most of the models examined. The present data suggest that altered calcium homoeostasis, as exhibited by increased calcium excretion, is associated with higher BP levels.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Paul Elliott
- Correspondence to Prof. Paul Elliott, MRC-HPA Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, St. Mary's Campus, Norfolk Place, London W2 1PG, United Kingdom (e-mail: )
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NKCC2 is activated in Milan hypertensive rats contributing to the maintenance of salt-sensitive hypertension. Pflugers Arch 2011; 462:281-91. [DOI: 10.1007/s00424-011-0967-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 04/01/2011] [Accepted: 04/03/2011] [Indexed: 01/11/2023]
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Programmed hypertension in rats treated with a NF-κB inhibitor during nephrogenesis: renal mechanisms. Hypertens Res 2011; 34:693-700. [PMID: 21326302 DOI: 10.1038/hr.2011.4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Suppression of the renin-angiotensin system (RAS) during murine lactation causes progressive renal injury, indicating a physiological action of angiotensin II on nephrogenesis. The nuclear factor NF-κB system is one of the main intracellular mediators of angiotensin II. We investigated whether inhibition of this system with pyrrolidine dithiocarbamate (PDTC) during rat nephrogenesis would lead to similar hypertension and renal injury as observed with RAS suppressors. Immediately after delivery, 32 Munich-Wistar dams, each nursing 6 male pups, were divided into 2 groups: C, untreated, and PDTC, receiving PDTC, 280 mg kg(-1) day(-1) orally, during 21 days. After weaning, the offspring were followed until 10 months of age without treatment. Adult rats that received neonatal PDTC exhibited stable hypertension and myocardial injury, without albuminuria. To gain additional insight into this process, the renal expression of RAS components and sodium transporters were determined by quantitative real-time PCR (qRT-PCR) at 3 and 10 months of life. Renal renin and angiotensinogen were upregulated at 3 and downregulated at 10 months of age, suggesting a role for early local RAS activation. Likewise, there was early upregulation of the proximal sodium/glucose and sodium/bicarbonate transporters, which abated later in life, suggesting that additional factors sustained hypertension in the long run. The conclusions drawn from the findings were as follows: (1) an intact NF-κB system during nephrogenesis may be essential to normal renal and cardiovascular function in adult life; (2) neonatal PDTC represents a new model of hypertension, lacking overt structural injury or functional impairment of the kidneys; and (3) hypertension in this model seems associated with early temporary activation of renal RAS and sodium transporters.
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Ruta LAM, Dickinson H, Thomas MC, Denton KM, Anderson WP, Kett MM. High-salt diet reveals the hypertensive and renal effects of reduced nephron endowment. Am J Physiol Renal Physiol 2010; 298:F1384-92. [PMID: 20335316 DOI: 10.1152/ajprenal.00049.2010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The extent to which a reduced nephron endowment contributes to hypertension and renal disease is confounded in models created by intrauterine insults that also demonstrate other phenotypes. Furthermore, recent data suggest that a reduced nephron endowment provides the "first hit" and simply increases the susceptibility to injurious stimuli. Thus we examined nephron number, glomerular volume, conscious mean arterial pressure (MAP), and renal function in a genetic model of reduced nephron endowment before and after a high-salt (5%) diet. One-yr-old glial cell line-derived neurotrophic factor wild-type (WT) mice, heterozygous (HET) mice born with two kidneys (HET2K), and HET mice born with one kidney (HET1K) were used. Nephron number was 25% lower in HET2K and 65% lower in HET1K than WT mice. Glomeruli hypertrophied in both HET groups by 33%, resulting in total glomerular volumes that were similar between HET2K and WT mice but remained 50% lower in HET1K mice. On a normal-salt diet, 24-h MAP was not different between WT, HET2K, and HET1K mice (102 +/- 1, 103 +/- 1, and 102 +/- 2 mmHg). On a high-salt diet, MAP increased 9.1 +/- 1.9 mmHg in HET1K mice (P < 0.05) and 5.4 +/- 0.9 mmHg in HET2K mice (P < 0.05) and did not change significantly in WT mice. Creatinine clearance was 60% higher in WT mice but 30% lower in HET2K and HET1K mice fed a high-salt diet than in controls maintained on a normal-salt diet. Thus a reduction in nephron number (or total glomerular volume) alone does not lead to hypertension or kidney disease in aged mice, but exposure to high salt uncovers a hypertensive and renal phenotype.
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Affiliation(s)
- Leah-Anne M Ruta
- Department of Physiology, Monash University, Clayton, Victoria, Australia
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Esteva-Font C, Wang X, Ars E, Guillén-Gómez E, Sans L, González Saavedra I, Torres F, Torra R, Masilamani S, Ballarín JA, Fernández-Llama P. Are sodium transporters in urinary exosomes reliable markers of tubular sodium reabsorption in hypertensive patients? Nephron Clin Pract 2010; 114:p25-34. [PMID: 20068364 DOI: 10.1159/000274468] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Accepted: 04/23/2009] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Altered renal sodium handling has a major pathogenic role in salt-sensitive hypertension. Renal sodium transporters are present in urinary exosomes. We hypothesized that sodium transporters would be excreted into the urine in different amounts in response to sodium intake in salt-sensitive versus salt-resistant patients. METHODS Urinary exosomes were isolated by ultracentrifugation, and their content of Na-K-2Cl cotransporter (NKCC2) and Na-Cl cotransporter (NCC) was analyzed by immunoblotting. Animal studies: NKCC2 and NCC excretion was measured in 2 rat models to test whether changes in sodium transporter excretion are indicative of regulated changes in the kidney tissue. Human studies: in hypertensive patients (n = 41), we investigated: (1) a possible correlation between sodium reabsorption and urinary exosomal excretion of sodium transporters, and (2) the profile of sodium transporter excretion related to blood pressure (BP) changes with salt intake. A 24-hour ambulatory BP monitoring and a 24-hour urine collection were performed after 1 week on a low- and 1 week on a high-salt diet. RESULTS Animal studies: urinary NKCC2 and NCC excretion rates correlated well with their abundance in the kidney. Human studies: 6 patients (15%) were classified as salt sensitive. The NKCC2 and NCC abundance did not decrease after the high-salt period, when the urinary sodium reabsorption decreased from 99.7 to 99.0%. In addition, the changes in BP with salt intake were not associated with a specific profile of exosomal excretion. CONCLUSIONS Our results do not support the idea that excretion levels of NKCC2 and NCC via urinary exosomes are markers of tubular sodium reabsorption in hypertensive patients.
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Affiliation(s)
- Cristina Esteva-Font
- Molecular Biology Laboratory, Universitat Autònoma de Barcelona, Fundació Puigvert, Barcelona, Spain
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The regulation of proximal tubular salt transport in hypertension: an update. Curr Opin Nephrol Hypertens 2009; 18:412-20. [PMID: 19654544 DOI: 10.1097/mnh.0b013e32832f5775] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
PURPOSE OF REVIEW Renal proximal tubular sodium reabsorption is regulated by sodium transporters, including the sodium glucose transporter, sodium amino acid transporter, sodium hydrogen exchanger isoform 3 and sodium phosphate cotransporter type 2 located at the luminal/apical membrane, and sodium bicarbonate cotransporter and Na+/K+ATPase located at the basolateral membrane. This review summarizes recent studies on sodium transporters that play a major role in the increase in blood pressure in essential/polygenic hypertension. RECENT FINDINGS Sodium transporters and Na+/K+ATPase are segregated in membrane lipid and nonlipid raft microdomains that regulate their activities and trafficking via cytoskeletal proteins. The increase in renal proximal tubule ion transport in polygenic hypertension is primarily due to increased activity of NHE3 and Cl/HCO3 exchanger at the luminal/apical membrane and a primary or secondary increase in Na+/K+ATPase activity. SUMMARY The increase in renal proximal tubule ion transport in hypertension is due to increased actions by prohypertensive factors that are unopposed by antihypertensive factors.
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