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Sandegaard SL, Riishede A, Birn H, Damkier HH, Praetorius J. The Cyst Epithelium in Polycystic Kidney Disease Patients Displays Normal Apical-Basolateral Cell Polarity. Int J Mol Sci 2024; 25:1904. [PMID: 38339183 PMCID: PMC10855726 DOI: 10.3390/ijms25031904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 02/12/2024] Open
Abstract
The main characteristic of polycystic kidney disease is the development of multiple fluid-filled renal cysts. The discovery of mislocalized sodium-potassium pump (Na,K-ATPase) in the apical membrane of cyst-lining epithelia alluded to reversal of polarity as a possible explanation for the fluid secretion. The topic of apical Na,K-ATPase in cysts remains controversial. We investigated the localization of the Na,K-ATPase and assessed the apical-basolateral polarization of cyst-lining epithelia by means of immunohistochemistry in kidney tissue from six polycystic kidney disease patients undergoing nephrectomy. The Na,K-ATPase α1 subunit was conventionally situated in the basolateral membrane of all immunoreactive cysts. Proteins of the Crumbs and partitioning defective (Par) complexes were localized to the apical membrane domain in cyst epithelial cells. The apical targeting protein Syntaxin-3 also immunolocalized to the apical domain of cyst-lining epithelial cells. Proteins of the basolateral Scribble complex immunolocalized to the basolateral domain of cysts. Thus, no deviations from the typical epithelial distribution of basic cell polarity proteins were observed in the cysts from the six patients. Furthermore, we confirmed that cysts can originate from virtually any tubular segment with preserved polarity. In conclusion, we find no evidence of a reversal in apical-basolateral polarity in cyst-lining epithelia in polycystic kidney disease.
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Affiliation(s)
- Samuel Loft Sandegaard
- Department of Biomedicine, Health Faculty, Aarhus University, DK-8000 Aarhus C, Denmark; (S.L.S.); (A.R.); (H.B.); (H.H.D.)
| | - Andreas Riishede
- Department of Biomedicine, Health Faculty, Aarhus University, DK-8000 Aarhus C, Denmark; (S.L.S.); (A.R.); (H.B.); (H.H.D.)
| | - Henrik Birn
- Department of Biomedicine, Health Faculty, Aarhus University, DK-8000 Aarhus C, Denmark; (S.L.S.); (A.R.); (H.B.); (H.H.D.)
- Department of Clinical Medicine, Health Faculty, Aarhus University, DK-8200 Aarhus N, Denmark
| | - Helle Hasager Damkier
- Department of Biomedicine, Health Faculty, Aarhus University, DK-8000 Aarhus C, Denmark; (S.L.S.); (A.R.); (H.B.); (H.H.D.)
| | - Jeppe Praetorius
- Department of Biomedicine, Health Faculty, Aarhus University, DK-8000 Aarhus C, Denmark; (S.L.S.); (A.R.); (H.B.); (H.H.D.)
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Johnsen LØ, Friis KA, Damkier HH. In vitro investigation of the effect of proinflammatory cytokines on mouse choroid plexus membrane transporters Ncbe and NKCC1. Fluids Barriers CNS 2023; 20:71. [PMID: 37828581 PMCID: PMC10568836 DOI: 10.1186/s12987-023-00474-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 10/04/2023] [Indexed: 10/14/2023] Open
Abstract
Intraventricular hemorrhage is a potentially life-threatening condition. Approximately 20% of patients develop posthemorrhagic hydrocephalus with increased ventricular volume and intracranial pressure. Hydrocephalus develops partially due to increased secretion of cerebrospinal fluid by the choroid plexus. During hemorrhage a multitude of factors are released into the cerebrospinal fluid. Many of these have been implicated in the hypersecretion. In this study, we have investigated the isolated effect of inflammatory components, on the abundance of two membrane transporters involved in cerebrospinal fluid secretion by the choroid plexus: the Na+-dependent Cl-/HCO3- exchanger, Ncbe, and the Na+, K+, 2Cl- cotransporter, NKCC1. We have established a primary choroid plexus epithelial cell culture from 1 to 7 days old mouse pups. Seven days after seeding, the cells formed a monolayer. The cells were treated with either tumor necrosis factor alpha (TNFα), interleukin 1 beta (IL-1β), or interleukin 6 (IL-6) to mimic inflammation. The data show that treatment with TNFα, and IL-1β only transiently increased NKCC1 abundance whereas the effect on Ncbe abundance was a transient decrease. IL-6 however significantly increased NKCC1 (242%), the phosphorylated NKCC1 (147%), as well as pSPAK (406%) abundance, but had no effect on Ncbe. This study suggests that the inflammatory pathway involved in hypersecretion primarily is mediated by activation of basolateral receptors in the choroid plexus, mainly facilitated by IL-6. This study highlights the complexity of the pathophysiological circumstances occurring during intraventricular hemorrhage.
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3
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Krogh TP, Isaksen C, Rojo-Manaute JM, Damkier HH, Jensen P, Fredberg U, Brix L. Implementation of ultrasound-guided carpal tunnel release. Dan Med J 2023; 70:A11220689. [PMID: 37622637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
INTRODUCTION Ultra-minimally invasive ultrasound-guided carpal tunnel release is a surgical procedure for treatment of carpal tunnel syndrome that is associated with less surgery-related morbidity and faster recovery than open surgery. The objectives of this study were to describe how the surgical technique may be acquired and to report the results obtained after implementation in a clinical setting. METHODS The study consisted of two parts: 1) description of the surgical skills needed to perform the procedure, and 2) evaluation of the procedure in the first ten consecutively operated patients after 12-month follow-up using questionnaires and magnetic resonance imaging (MRI). RESULTS The procedure was performed on 29 cadaveric arms and assessed regarding surgical release success and signs of iatrogenic damage. Subsequently, the procedure was performed on ten patients with carpal tunnel syndrome. The results of the six-item Carpal Tunnel Symptoms Scale (1-5) improved from 3.3 ± 0.9 (mean ± standard deviation) preoperatively to 1.2 ± 0.3, p = 0.002, after 12 months. Quick Disabilities of the Arm, Shoulder and Hand (DASH) (0-100) results improved from 33.4 ± 14.8 to 2.3 ± 4.0, p = 0.002. There were no infections or iatrogenic damage to nerves or blood vessels. CONCLUSIONS This study presents a way to safely acquire the skills needed to perform the procedure and implement it in an out-patient setting. The results were comparable to previous findings regarding both effectiveness and safety. MRI documented the surgical gap in the transverse carpal ligament, release length, cross-sectional area changes in the carpal tunnel and median nerve, and reactive changes in the carpal tunnel. FUNDING None. TRIAL REGISTRATION Not relevant.
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Affiliation(s)
- Thøger Persson Krogh
- Diagnostic Centre, University Research Clinic for Innovative Patient Pathways, Silkeborg Regional Hospital
- Center for Sports Medicine, Regional Hospital of Northern Denmark, Frederikshavn
| | - Christin Isaksen
- Diagnostic Centre, University Research Clinic for Innovative Patient Pathways, Silkeborg Regional Hospital
| | | | | | - Pia Jensen
- Diagnostic Centre, University Research Clinic for Innovative Patient Pathways, Silkeborg Regional Hospital
| | - Ulrich Fredberg
- Diagnostic Centre, University Research Clinic for Innovative Patient Pathways, Silkeborg Regional Hospital
- Center for Sports Medicine, Regional Hospital of Northern Denmark, Frederikshavn
- Research Unit of Rheumatology, Department of Clinical Research, Odense University Hospital
- Institute of Sports Medicine Copenhagen, Copenhagen University Hospital - Bispebjerg Hospital
| | - Lau Brix
- Diagnostic Centre, University Research Clinic for Innovative Patient Pathways, Silkeborg Regional Hospital
- Department of Procurement and Biomedical Engineering, Region Midtjylland
- Comparative Medicine Lab, Department of Clinical Medicine, Aarhus University, Denmark
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4
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Wichmann TO, Damkier HH, Pedersen M. A Brief Overview of the Cerebrospinal Fluid System and Its Implications for Brain and Spinal Cord Diseases. Front Hum Neurosci 2022; 15:737217. [PMID: 35126070 PMCID: PMC8813779 DOI: 10.3389/fnhum.2021.737217] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 12/29/2021] [Indexed: 12/04/2022] Open
Abstract
A comprehensive understanding of the cerebrospinal fluid (CSF) system is essential for our understanding of health and disease within the central nervous system (CNS). The system of CSF refers to all components involved in CSF production, movement, and absorption. In recent years, extensive research has resulted in vastly improved understanding of the CSF system in health and disease. Yet, several aspects remain to be fully clarified, notably along the spinal cord as the preponderance of research has focused on the brain. This review briefly summarizes the CSF system and its implications for CNS diseases and highlights the knowledge gaps that require further research.
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Affiliation(s)
- Thea Overgaard Wichmann
- Department of Neurosurgery, Aarhus University Hospital, Aarhus, Denmark
- *Correspondence: Thea Overgaard Wichmann
| | | | - Michael Pedersen
- Comparative Medicine Lab, Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark
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Christensen IB, Wu Q, Bohlbro AS, Skals MG, Damkier HH, Hübner CA, Fenton RA, Praetorius J. Genetic disruption of slc4a10 alters the capacity for cellular metabolism and vectorial ion transport in the choroid plexus epithelium. Fluids Barriers CNS 2020; 17:2. [PMID: 31906971 PMCID: PMC6945596 DOI: 10.1186/s12987-019-0162-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/12/2019] [Indexed: 02/02/2023] Open
Abstract
Background Genetic disruption of slc4a10, which encodes the sodium-dependent chloride/bicarbonate exchanger Ncbe, leads to a major decrease in Na+-dependent HCO3− import into choroid plexus epithelial cells in mice and to a marked reduction in brain intraventricular fluid volume. This suggests that Ncbe functionally is a key element in vectorial Na+ transport and thereby for cerebrospinal fluid secretion in the choroid plexus. However, slc4a10 disruption results in severe changes in expression of Na+,K+-ATPase complexes and other major transport proteins, indicating that profound cellular changes accompany the genetic manipulation. Methods A tandem mass tag labeling strategy was chosen for quantitative mass spectrometry. Alterations in the broader patterns of protein expression in the choroid plexus in response to genetic disruption of Ncbe was validated by semi-quantitative immunoblotting, immunohistochemistry and morphometry. Results The abundance of 601 proteins were found significantly altered in the choroid plexus from Ncbe ko mice relative to Ncbe wt. In addition to a variety of transport proteins, particularly large changes in the abundance of proteins involved in cellular energy metabolism were detected in the Ncbe ko mice. In general, the abundance of rate limiting glycolytic enzymes and several mitochondrial enzymes were reduced following slc4a10 disruption. Surprisingly, this was accompanied by increased ATP levels in choroid plexus cells, indicating that the reduction in capacity for energy metabolism was adaptive to high ATP rather than causal for a decreased capacity for ion and water transport. Ncbe-deficient cells also had a reduced cell area and decreased K+ content. Conclusion Our findings suggest that the lack of effective Na+-entry into the epithelial cells of the choroid plexus leads to a profound change in the cellular phenotype, shifting from a high-rate secretory function towards a more dormant state; similar to what is observed during ageing or Alzheimer’s disease.
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Affiliation(s)
- Inga Baasch Christensen
- Department of Biomedicine, Health, Aarhus University, Wilhelm Meyers Allé 3, r. 219, 8000, Aarhus C, Denmark
| | - Qi Wu
- Department of Biomedicine, Health, Aarhus University, Wilhelm Meyers Allé 3, r. 219, 8000, Aarhus C, Denmark
| | - Anders Solitander Bohlbro
- Department of Biomedicine, Health, Aarhus University, Wilhelm Meyers Allé 3, r. 219, 8000, Aarhus C, Denmark
| | - Marianne Gerberg Skals
- Department of Biomedicine, Health, Aarhus University, Wilhelm Meyers Allé 3, r. 219, 8000, Aarhus C, Denmark
| | - Helle Hasager Damkier
- Department of Biomedicine, Health, Aarhus University, Wilhelm Meyers Allé 3, r. 219, 8000, Aarhus C, Denmark
| | - Christian Andreas Hübner
- Department of Biomedicine, Health, Aarhus University, Wilhelm Meyers Allé 3, r. 219, 8000, Aarhus C, Denmark
| | - Robert Andrew Fenton
- Department of Biomedicine, Health, Aarhus University, Wilhelm Meyers Allé 3, r. 219, 8000, Aarhus C, Denmark
| | - Jeppe Praetorius
- Department of Biomedicine, Health, Aarhus University, Wilhelm Meyers Allé 3, r. 219, 8000, Aarhus C, Denmark.
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6
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Praetorius J, Damkier HH. Ncbe (
slc4a10
) is a major Na
+
loader in the mouse choroid plexus epithelium. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.544.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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7
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Christensen IB, Mogensen EN, Damkier HH, Praetorius J. Choroid plexus epithelial cells express the adhesion protein P-cadherin at cell-cell contacts and syntaxin-4 in the luminal membrane domain. Am J Physiol Cell Physiol 2018; 314:C519-C533. [PMID: 29351408 DOI: 10.1152/ajpcell.00305.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The choroid plexus epithelial cells (CPECs) belong to a small group of polarized cells, where the Na+-K+-ATPase is expressed in the luminal membrane. The basic polarity of the cells is, therefore, still debated. We investigated the subcellular distribution of an array of proteins known to play fundamental roles either in establishing and maintaining basic cell polarity or in the polarized delivery and recycling of plasma membrane proteins. Immunofluorescence histochemical analysis was applied to determine the subcellular localization of apical and basolateral membrane determinants. Mass spectrometry analysis of CPECs isolated by fluorescence-activated cell sorting was applied to determine the expression of specific forms of the proteins. CPECs mainly express the cell-adhesive P-cadherin, which is localized to the lateral membranes. Proteins belonging to the Crumbs and partitioning defective (Par) protein complexes were all localized to the luminal membrane domain. Par-1 and the Scribble complex were localized to the basolateral membrane domain. Lethal(2) giant larvae homolog 2 (Lgl2) labeling was preferentially observed in the luminal membrane domain. Phosphatidylinositol 3,4,5-trisphosphate (PIP3) was immunolocalized to the basolateral membrane domain, while phosphatidylinositol 4,5-bisphosphate (PIP2) staining was most prominent in the luminal membrane domain along with the PIP3 phosphatase, Pten. The apical target-SNARE syntaxin-3 and the basolateral target-SNARE syntaxin-4 were both localized to the apical membrane domain in CPECs, which lack cellular expression of the clathrin adaptor protein AP-1B for basolateral protein recycling. In conclusion, the CPECs are conventionally polarized, but express P-cadherin at cell-cell contacts, and Lgl2 and syntaxin-4 in the luminal plasma membrane domain.
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Affiliation(s)
| | | | | | - Jeppe Praetorius
- Department of Biomedicine, Health, Aarhus University , Aarhus, Denmark
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8
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Praetorius J, Damkier HH. Transport across the choroid plexus epithelium. Am J Physiol Cell Physiol 2017; 312:C673-C686. [PMID: 28330845 DOI: 10.1152/ajpcell.00041.2017] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 03/17/2017] [Accepted: 03/17/2017] [Indexed: 11/22/2022]
Abstract
The choroid plexus epithelium is a secretory epithelium par excellence. However, this is perhaps not the most prominent reason for the massive interest in this modest-sized tissue residing inside the brain ventricles. Most likely, the dominant reason for extensive studies of the choroid plexus is the identification of this epithelium as the source of the majority of intraventricular cerebrospinal fluid. This finding has direct relevance for studies of diseases and conditions with deranged central fluid volume or ionic balance. While the concept is supported by the vast majority of the literature, the implication of the choroid plexus in secretion of the cerebrospinal fluid was recently challenged once again. Three newer and promising areas of current choroid plexus-related investigations are as follows: 1) the choroid plexus epithelium as the source of mediators necessary for central nervous system development, 2) the choroid plexus as a route for microorganisms and immune cells into the central nervous system, and 3) the choroid plexus as a potential route for drug delivery into the central nervous system, bypassing the blood-brain barrier. Thus, the purpose of this review is to highlight current active areas of research in the choroid plexus physiology and a few matters of continuous controversy.
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Affiliation(s)
- Jeppe Praetorius
- Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark; and
| | - Helle Hasager Damkier
- Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark; and.,Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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9
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Jensen TB, Cheema MU, Szymiczek A, Damkier HH, Praetorius J. Renal type a intercalated cells contain albumin in organelles with aldosterone-regulated abundance. PLoS One 2015; 10:e0124902. [PMID: 25874770 PMCID: PMC4395387 DOI: 10.1371/journal.pone.0124902] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 03/17/2015] [Indexed: 11/18/2022] Open
Abstract
Albumin has been identified in preparations of renal distal tubules and collecting ducts by mass spectrometry. This study aimed to establish whether albumin was a contaminant in those studies or actually present in the tubular cells, and if so, identify the albumin containing cells and commence exploration of the origin of the intracellular albumin. In addition to the expected proximal tubular albumin immunoreactivity, albumin was localized to mouse renal type-A intercalated cells and cells in the interstitium by three anti-albumin antibodies. Albumin did not colocalize with markers for early endosomes (EEA1), late endosomes/lysosomes (cathepsin D) or recycling endosomes (Rab11). Immuno-gold electron microscopy confirmed the presence of albumin-containing large spherical membrane associated bodies in the basal parts of intercalated cells. Message for albumin was detected in mouse renal cortex as well as in a wide variety of other tissues by RT-PCR, but was absent from isolated connecting tubules and cortical collecting ducts. Wild type I MDCK cells showed robust uptake of fluorescein-albumin from the basolateral side but not from the apical side when grown on permeable support. Only a subset of cells with low peanut agglutinin binding took up albumin. Albumin-aldosterone conjugates were also internalized from the basolateral side by MDCK cells. Aldosterone administration for 24 and 48 hours decreased albumin abundance in connecting tubules and cortical collecting ducts from mouse kidneys. We suggest that albumin is produced within the renal interstitium and taken up from the basolateral side by type-A intercalated cells by clathrin and dynamin independent pathways and speculate that the protein might act as a carrier of less water-soluble substances across the renal interstitium from the capillaries to the tubular cells.
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Affiliation(s)
| | | | - Agata Szymiczek
- Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark
| | | | - Jeppe Praetorius
- Department of Biomedicine, Health, Aarhus University, Aarhus, Denmark
- * E-mail:
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10
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Cheema MU, Damkier HH, Nielsen J, Poulsen ET, Enghild JJ, Fenton RA, Praetorius J. Distal renal tubules are deficient in aggresome formation and autophagy upon aldosterone administration. PLoS One 2014; 9:e101258. [PMID: 25000288 PMCID: PMC4085037 DOI: 10.1371/journal.pone.0101258] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 06/04/2014] [Indexed: 11/18/2022] Open
Abstract
Prolonged elevations of plasma aldosterone levels are associated with renal pathogenesis. We hypothesized that renal distress could be imposed by an augmented aldosterone-induced protein turnover challenging cellular protein degradation systems of the renal tubular cells. Cellular accumulation of specific protein aggregates in rat kidneys was assessed after 7 days of aldosterone administration. Aldosterone induced intracellular accumulation of 60 s ribosomal protein L22 in protein aggregates, specifically in the distal convoluted tubules. The mineralocorticoid receptor inhibitor spironolactone abolished aldosterone-induced accumulation of these aggregates. The aldosterone-induced protein aggregates also contained proteasome 20 s subunits. The partial de-ubiquitinase ataxin-3 was not localized to the distal renal tubule protein aggregates, and the aggregates only modestly colocalized with aggresome transfer proteins dynactin p62 and histone deacetylase 6. Intracellular protein aggregation in distal renal tubules did not lead to development of classical juxta-nuclear aggresomes or to autophagosome formation. Finally, aldosterone treatment induced foci in renal cortex of epithelial vimentin expression and a loss of E-cadherin expression, as signs of cellular stress. The cellular changes occurred within high, but physiological aldosterone concentrations. We conclude that aldosterone induces protein accumulation in distal renal tubules; these aggregates are not cleared by autophagy that may lead to early renal tubular damage.
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Affiliation(s)
- Muhammad Umar Cheema
- Department of Biomedicine, Membranes Center & InterPrET Pilot Center, Health, Aarhus University, Aarhus, Denmark
| | - Helle Hasager Damkier
- Department of Biomedicine, Membranes Center & InterPrET Pilot Center, Health, Aarhus University, Aarhus, Denmark
| | - Jakob Nielsen
- Department of Biomedicine, Membranes Center & InterPrET Pilot Center, Health, Aarhus University, Aarhus, Denmark
| | - Ebbe Toftgaard Poulsen
- Department of Molecular Biology and Genetics, iNano, Science and Technology, Aarhus University, Aarhus, Denmark
| | - Jan J. Enghild
- Department of Molecular Biology and Genetics, iNano, Science and Technology, Aarhus University, Aarhus, Denmark
| | - Robert A. Fenton
- Department of Biomedicine, Membranes Center & InterPrET Pilot Center, Health, Aarhus University, Aarhus, Denmark
| | - Jeppe Praetorius
- Department of Biomedicine, Membranes Center & InterPrET Pilot Center, Health, Aarhus University, Aarhus, Denmark
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Nguyen AT, Praetorius J, Damkier HH. A novel plate reader based assay for inhibitor studies of
slc4a10
protein and other acid/base transporters. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.730.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- An Tuyet Nguyen
- Department of Biomedicine, HealthAarhus UniversityAarhusDenmark
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12
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Damkier HH, Praetorius J. Atypical localization of cytoskeletal and anchoring proteins in the choroid plexus of normal and
slc4a10
knockout mice. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.730.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Christensen HL, Damkier HH, Brown D, Praetorius J. The choroid plexus regulation of cerebrospinal fluid pH. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.730.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Dennis Brown
- Program in Membrane BiologyHarvard Medical SchoolMassachusetts General HospitalBostonMA
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Damkier HH, Praetorius J. Genetic ablation of Slc4a10 alters the expression pattern of transporters involved in solute movement in the mouse choroid plexus. Am J Physiol Cell Physiol 2012; 302:C1452-9. [PMID: 22357733 DOI: 10.1152/ajpcell.00285.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mutational changes of one transporter can have deleterious effects on epithelial function leaving the cells with the options of either compensating for the loss of function or dedifferentiating. Previous studies have shown that the choroid plexus epithelium (CPE) from mice lacking the Na(+)-dependent Cl(-)/HCO(3)(-) exchanger (NCBE) encoded by Slc4a10 leads to retargeting of the Na(+)/H(+) exchanger 1 (NHE1) from the luminal to the basolateral plasma membrane. We hypothesized that disruption of NCBE, the main basolateral Na(+) importer in the CPE, would lead to a compensatory increase in the abundance of other important transport proteins in this tissue. Aquaporin-1 (AQP1) abundance was 42.7% lower and Na,K-ATPase 36.4% lower in the CPE of Slc4a10 knockout mice, respectively. The NHE1 binding ezrin cytoskeleton appeared disrupted in Slc4a10 knockout mice, whereas no changes were observed in cellular polarization with respect to claudin-2 and appearance of luminal surface microvilli. The renal proximal tubule constitutes a leaky epithelium with high transport rate similar to CPE. Here, Slc4a10 knockout did not affect Na,K-ATPase or AQP1 expression. CPE from AQP1 knockout mice has a secretory defect similar to Slc4a10 mice. However, neither NCBE nor Na,K-ATPase expression was affected in CPE from AQP1 knockout mice. By contrast, the abundance of Na,K-ATPase and NBCe1 was decreased by 23 and 31.7%, respectively, in AQP1 knockout proximal tubules, while the NHE3 abundance was unchanged. In conclusion, CPE lacking NCBE seems to spare the molecular machinery involved in CSF secretion rather than compensate for the loss of the Na(+) loader. Slc4a10 knockout seems to be more deleterious to CPE than AQP1 knockout.
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Affiliation(s)
- Helle Hasager Damkier
- Department of Biomedicine, Aarhus University, Wilhelm Meyers Allé 3, Bldg. 1233/1234, DK-8000 Aarhus C, Denmark.
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15
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Hofmeister MV, Damkier HH, Christensen BM, Olde B, Fredrik Leeb-Lundberg LM, Fenton RA, Praetorius HA, Praetorius J. 17β-Estradiol induces nongenomic effects in renal intercalated cells through G protein-coupled estrogen receptor 1. Am J Physiol Renal Physiol 2011; 302:F358-68. [PMID: 21993891 DOI: 10.1152/ajprenal.00343.2011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Steroid hormones such as 17β-estradiol (E2) are known to modulate ion transporter expression in the kidney through classic intracellular receptors. Steroid hormones are also known to cause rapid nongenomic responses in a variety of nonrenal tissues. However, little is known about renal short-term effects of steroid hormones. Here, we studied the acute actions of E2 on intracellular Ca(2+) signaling in isolated distal convoluted tubules (DCT2), connecting tubules (CNT), and initial cortical collecting ducts (iCCD) by fluo 4 fluorometry. Physiological concentrations of E2 induced transient increases in intracellular Ca(2+) concentration ([Ca(2+)](i)) in a subpopulation of cells. The [Ca(2+)](i) increases required extracellular Ca(2+) and were inhibited by Gd(3+). Strikingly, the classic E2 receptor antagonist ICI 182,780 also increased [Ca(2+)](i), which is inconsistent with the activation of classic E2 receptors. G protein-coupled estrogen receptor 1 (GPER1 or GPR30) was detected in microdissected DCT2/CNT/iCCD by RT-PCR. Stimulation with the specific GPER1 agonist G-1 induced similar [Ca(2+)](i) increases as E2, and in tubules from GPER1 knockout mice, E2, G-1, and ICI 182,780 failed to induce [Ca(2+)](i) elevations. The intercalated cells showed both E2-induced concanamycin-sensitive H(+)-ATPase activity by BCECF fluorometry and the E2-mediated [Ca(2+)](i) increment. We propose that E2 via GPER1 evokes [Ca(2+)](i) transients and increases H(+)-ATPase activity in intercalated cells in mouse DCT2/CNT/iCCD.
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Abstract
The slc4a10 gene encodes an electroneutral Na(+)-dependent HCO(3)(-) importer for which the precise mode of action remains unsettled. To resolve this issue, intracellular pH (pH(i)) recordings were performed upon acidification in the presence of CO(2)/HCO(3)(-) by 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF) fluorometry of stably slc4a10-transfected NIH-3T3 fibroblasts. slc4a10 expression induced a significant Na(+)-dependent pH(i) recovery, which was accompanied by an increase in the intracellular Na(+) concentration evaluated by use of the Na(+)-sensitive fluorophore CoroNa Green. The estimated Na(+):HCO(3)(-) stoichiometry was 1:2. Cl(-) is most likely the counterion maintaining electroneutrality because (i) Na(+)-dependent pH(i) recovery was eliminated in Cl(-)-depleted cells; (ii) acute extracellular Cl(-) removal led to a larger alkalization in slc4a10-transfected cells than in control cells; and (iii) the 4,4'-diisothiocyanato-stilbene-2,2'-disulfonic acid (DIDS)-sensitive and Na(+)- and HCO(3)(-)-dependent (36)Cl(-)-efflux during pH(i) recovery was significantly greater in acidified slc4a10-transfected cells than in control cells. Charged amino acids specific to slc4a gene family members that transport Na(+) and are expected to move more HCO(3)(-) molecules/turnover were targeted by site-directed mutagenesis. Na(+)-dependent pH(i) recovery was reduced in each of the single amino acid mutated cell lines (E890A, E892A, H976L, and H980G) compared with wild type slc4a10-transfected cells and completely eliminated in quadruple mutant cells. In conclusion, the data suggest that slc4a10 expressed in mammalian cells encodes a Na(+)-dependent Cl(-)/HCO(3)(-) exchanger in which four specific charged amino acids seem necessary for ion transport.
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Affiliation(s)
- Helle Hasager Damkier
- Water and Salt Research Center, Aarhus University, DK-8000 Aarhus, Denmark; Department of Anatomy, Aarhus University, DK-8000 Aarhus, Denmark.
| | - Christian Aalkjaer
- Water and Salt Research Center, Aarhus University, DK-8000 Aarhus, Denmark; Department of Physiology and Biophysics, Aarhus University, DK-8000 Aarhus, Denmark
| | - Jeppe Praetorius
- Water and Salt Research Center, Aarhus University, DK-8000 Aarhus, Denmark; Department of Anatomy, Aarhus University, DK-8000 Aarhus, Denmark
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Damkier HH, Aalkjaer C, Praetorius J. Identification of 4 charged amino acids essential for
Slc4a10
‐derived protein function. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.815.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Christian Aalkjaer
- Water and Salt Research CenterDepartment of Physiology and BiophysicsAarhus UniversityAarhusDenmark
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Damkier HH, Prasad V, Hübner CA, Praetorius J. Nhe1 is a luminal Na+/H+ exchanger in mouse choroid plexus and is targeted to the basolateral membrane in Ncbe/Nbcn2-null mice. Am J Physiol Cell Physiol 2009; 296:C1291-300. [PMID: 19369449 DOI: 10.1152/ajpcell.00062.2009] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The choroid plexus epithelium (CPE) secretes the major fraction of the cerebrospinal fluid (CSF). The Na(+)-HCO(3)(-) transporter Ncbe/Nbcn2 in the basolateral membrane of CPE cells is important for Na(+)-dependent pH(i) increases and probably for CSF secretion. In the current study, the anion transport inhibitor DIDS had no effect on the residual pH(i) recovery in acidified CPE from Ncbe/Nbcn2 knockout mouse by 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF)-fluorescence microscopy in the presence of CO(2)/HCO(3)(-) (Ncbe/Nbcn2-ko+DIDS 109% of control, P = 0.76, n = 5). Thus Ncbe/Nbcn2 mediates the DIDS-sensitive Na(+)-dependent pH(i) recovery in the CPE. The Na(+)/H(+) exchanger-1 Nhe1 is proposed to mediate similar functions as Ncbe/Nbcn2 in CPE. Here, we immunolocalize the Nhe1 protein to the luminal membrane domain in mouse and human CPE. The Na(+)-dependent pH(i) recovery of Nhe1 wild-type (Nhe1-wt) mice in the absence of CO(2)/HCO(3)(-) was abolished in the Nhe1 knockout CPE (Nhe1-ko 0.37% of Nhe1-wt, P = 0.0007, n = 5). In Ncbe/Nbcn2-ko mice, Nhe1 was targeted to the basolateral membrane. Nevertheless, the luminal Na(+)-dependent pH(i) recovery was increased in Ncbe/Nbcn2-ko compared with wild-type littermates (Nhe1-ko 146% of Nhe1-wt, P = 0.007, n = 5). Whereas the luminal Nhe activity was inhibited by the Nhe blocker EIPA (10 microM) in the Ncbe/Nbcn2-wt, it was insensitive to the inhibitor in Ncbe/Nbcn2-ko (Ncbe/Nbcn2-ko+EIPA 100% of control, P = 0.98, n = 5). This indicates that a luminal EIPA-insensitive Nhe was induced in Ncbe/Nbcn2-ko CPE and that EIPA-sensitive Nhe activity was basolateral. The Nhe1 translocation in Ncbe/Nbcn2-ko CPE may reflect a compensatory response, which provides the cells with better means of regulating pH(i) or transporting Na(+) after Ncbe/Nbcn2 disruption.
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Damkier HH, Praetorius J. Identification of 4 charged amino acids necessary for Slc4a10‐derived protein function. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.800.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Helle Hasager Damkier
- Department of Anatomy and the Water and Salt Research CenterAarhus UniversityAarhusDenmark
| | - Jeppe Praetorius
- Department of Anatomy and the Water and Salt Research CenterAarhus UniversityAarhusDenmark
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Damkier HH, Jacobs S, Haapanen A, Tyynelä J, Hübner CA, Praetorius J. Decreased Na
+
‐dependent acid/base transport in choroid plexus of NCBE knock‐out mice. FASEB J 2008. [DOI: 10.1096/fasebj.22.2_supplement.180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Stefan Jacobs
- Department of Human GeneticsUniversitätsklinik Hamburg‐EppendorfHamburg UniversityHamburgGermany
| | - Aleksi Haapanen
- Institute of Biomedicine/Biochemistry BiomedicumUniversity of HelsinkiHelsinkiFinland
- Experimental MRI LaboratoryDepartment of NeurologyHelsinki University Central HospitalHelsinkiFinland
| | - Jaana Tyynelä
- Institute of Biomedicine/Biochemistry BiomedicumUniversity of HelsinkiHelsinkiFinland
- Experimental MRI LaboratoryDepartment of NeurologyHelsinki University Central HospitalHelsinkiFinland
| | - Christian A Hübner
- Department of Human GeneticsUniversitätsklinik Hamburg‐EppendorfHamburg UniversityHamburgGermany
- Department of Clinical ChemistryFriedrich‐Schiller‐Universität JenaJenaGermany
| | - Jeppe Praetorius
- Water and Salt Research CenterDept. of AnatomyUniversity of AarhusAarhusDenmark
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Damkier HH, Nielsen S, Praetorius J. Molecular expression of SLC4-derived Na+-dependent anion transporters in selected human tissues. Am J Physiol Regul Integr Comp Physiol 2007; 293:R2136-46. [PMID: 17715183 DOI: 10.1152/ajpregu.00356.2007] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
NaHCO(3) transporters are involved in maintenance of intracellular pH and transepithelial HCO(3)(-) movement in many rodent tissues. To establish the human relevance of the many investigations on rodents, this study aimed to map these transporters and a related polypeptide, NaBC1 [solute carrier 4 (SLC4)A11], to several human tissues by using PCR on reverse transcribed human mRNA and immunoperoxidase histochemistry. The mRNA encoding the electroneutral Na(+):HCO(3)(-) cotransporter (NBCe1; SLC4A4), was expressed in renal cortex, renal medulla, stomach, duodenum, jejunum, ileum, colon, pancreas, choroid plexus, cerebellum, cerebrum, and hippocampus. NBCe2 (SLC4A5) and NBCn1 (SLC4A7) mRNAs were mainly found in kidney and brain tissues, as was mRNA encoding the Na(+)-dependent anion exchangers NCBE (SLC4A10) and NDCBE1 (SLC4A8). In addition to previous findings, NBCn1 protein was localized to human renal medullary thick ascending limbs and duodenal epithelial villus cells and NBCe2 protein to renal collecting ducts. Finally, the message encoding NaBC1 was found in kidney, stomach, duodenum, pancreas, and brain, and the corresponding protein in the anterior and posterior corneal epithelia, renal corpuscules, proximal tubules, collecting ducts, pancreatic ducts, and the choroid plexus epithelium. In conclusion, the selected human tissues display distinct expression patterns of HCO(3)(-) transporters, which closely resemble that of rodent tissues.
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Affiliation(s)
- Helle Hasager Damkier
- The Water and Salt Research Center, Institute of Anatomy, University of Aarhus, Wilhelm Meyers Allé, Bldg. 1-234, 8000 Aarhus C, Denmark
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Damkier HH, Nielsen S, Praetorius J. An anti-NH2-terminal antibody localizes NBCn1 to heart endothelia and skeletal and vascular smooth muscle cells. Am J Physiol Heart Circ Physiol 2005; 290:H172-80. [PMID: 16126812 DOI: 10.1152/ajpheart.00713.2005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The electroneutral sodium bicarbonate cotransporter NBCn1 or NBC3 was originally cloned from rat aorta and from human skeletal muscle. NBCn1 (or NBC3) has been localized to the basolateral membrane of various epithelia, but thus far it has been impossible to detect the protein in these tissues by using anti-COOH-terminal antibodies. Hence an antibody was developed against the NH2-terminus of NBCn1 and was validated by peptide recognition and immunoblotting on positive control tissues and by binding of an approximately 180-kDa protein in the rat kidney, cerebrum, cerebellum, and duodenum. In addition, an approximately 180-kDa immunoreactive band appeared using samples from the aorta, heart ventricles and atria, mesenteric arteries, lung, spleen, liver, pancreas, and epididymis. Immunohistochemical analysis confirmed the previously described labeling in the kidney, duodenum, and the choroid plexus. The anti-NH2-terminal antibody localized NBCn1 to the plasma membrane domains of endothelia and smooth muscle cells in small mesenteric and renal arteries, as well as the capillaries of the heart ventricles, spleen, and salivary glands. NBCn1 was also detected in neuromuscular junctions and vasculature in skeletal muscle. Analysis of variable NBCn1 splicing by RT-PCR revealed that an NH2-terminal sequence, the cassette III, seems absent from cardiovascular NBCn1 and that both cassettes I and III are variable in most epithelia, whereas cassette II is absent from epithelial NBCn1. Thus the development of the NH2-terminal antibody allowed the localization of NBCn1 protein to major cardiovascular tissues where NBCn1 mRNA was previously detected. The NBCn1 is a likely candidate for mediating the reported electroneutral Na+-HCO3(-) cotransport in vascular smooth muscle.
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Affiliation(s)
- Helle Hasager Damkier
- Water and Salt Research Center, Institute of Anatomy, Univ. of Aarhus, Wilhelm Meyers Allé, Bldg. 234, 8000 Aarhus C, Denmark
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