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Holmberg SR, Sakamoto Y, Kato A, Romero MF. The role of Na +-coupled bicarbonate transporters (NCBT) in health and disease. Pflugers Arch 2024; 476:479-503. [PMID: 38536494 DOI: 10.1007/s00424-024-02937-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 04/11/2024]
Abstract
Cellular and organism survival depends upon the regulation of pH, which is regulated by highly specialized cell membrane transporters, the solute carriers (SLC) (For a comprehensive list of the solute carrier family members, see: https://www.bioparadigms.org/slc/ ). The SLC4 family of bicarbonate (HCO3-) transporters consists of ten members, sorted by their coupling to either sodium (NBCe1, NBCe2, NBCn1, NBCn2, NDCBE), chloride (AE1, AE2, AE3), or borate (BTR1). The ionic coupling of SLC4A9 (AE4) remains controversial. These SLC4 bicarbonate transporters may be controlled by cellular ionic gradients, cellular membrane voltage, and signaling molecules to maintain critical cellular and systemic pH (acid-base) balance. There are profound consequences when blood pH deviates even a small amount outside the normal range (7.35-7.45). Chiefly, Na+-coupled bicarbonate transporters (NCBT) control intracellular pH in nearly every living cell, maintaining the biological pH required for life. Additionally, NCBTs have important roles to regulate cell volume and maintain salt balance as well as absorption and secretion of acid-base equivalents. Due to their varied tissue expression, NCBTs have roles in pathophysiology, which become apparent in physiologic responses when their expression is reduced or genetically deleted. Variations in physiological pH are seen in a wide variety of conditions, from canonically acid-base related conditions to pathologies not necessarily associated with acid-base dysfunction such as cancer, glaucoma, or various neurological diseases. The membranous location of the SLC4 transporters as well as recent advances in discovering their structural biology makes them accessible and attractive as a druggable target in a disease context. The role of sodium-coupled bicarbonate transporters in such a large array of conditions illustrates the potential of treating a wide range of disease states by modifying function of these transporters, whether that be through inhibition or enhancement.
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Affiliation(s)
- Shannon R Holmberg
- Physiology & Biomedical Engineering, Mayo Clinic College of Medicine & Science, 200 1st Street SW, Rochester, MN 55905, USA
- Biochemistry & Molecular Biology, Mayo Clinic College of Medicine & Science, 200 1st Street SW, Rochester, MN, USA
| | - Yohei Sakamoto
- School of Life Science and Technology, Tokyo Institute of Technology, Midori-Ku, Yokohama, 226-8501, Japan
| | - Akira Kato
- School of Life Science and Technology, Tokyo Institute of Technology, Midori-Ku, Yokohama, 226-8501, Japan
| | - Michael F Romero
- Physiology & Biomedical Engineering, Mayo Clinic College of Medicine & Science, 200 1st Street SW, Rochester, MN 55905, USA.
- Nephrology & Hypertension, Mayo Clinic College of Medicine & Science, 200 1st Street SW, Rochester, MN, USA.
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2
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Qin N, Li L, Wan X, Ji X, Chen Y, Li C, Liu P, Zhang Y, Yang W, Jiang J, Xia J, Shi S, Tan T, Nielsen J, Chen Y, Liu Z. Increased CO 2 fixation enables high carbon-yield production of 3-hydroxypropionic acid in yeast. Nat Commun 2024; 15:1591. [PMID: 38383540 PMCID: PMC10881976 DOI: 10.1038/s41467-024-45557-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 01/28/2024] [Indexed: 02/23/2024] Open
Abstract
CO2 fixation plays a key role to make biobased production cost competitive. Here, we use 3-hydroxypropionic acid (3-HP) to showcase how CO2 fixation enables approaching theoretical-yield production. Using genome-scale metabolic models to calculate the production envelope, we demonstrate that the provision of bicarbonate, formed from CO2, restricts previous attempts for high yield production of 3-HP. We thus develop multiple strategies for bicarbonate uptake, including the identification of Sul1 as a potential bicarbonate transporter, domain swapping of malonyl-CoA reductase, identification of Esbp6 as a potential 3-HP exporter, and deletion of Uga1 to prevent 3-HP degradation. The combined rational engineering increases 3-HP production from 0.14 g/L to 11.25 g/L in shake flask using 20 g/L glucose, approaching the maximum theoretical yield with concurrent biomass formation. The engineered yeast forms the basis for commercialization of bio-acrylic acid, while our CO2 fixation strategies pave the way for CO2 being used as the sole carbon source.
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Affiliation(s)
- Ning Qin
- College of Life Science and Technology, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Lingyun Li
- College of Life Science and Technology, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
- Department of Life Sciences, Chalmers University of Technology, SE412 96, Gothenburg, Sweden
| | - Xiaozhen Wan
- College of Life Science and Technology, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Xu Ji
- College of Life Science and Technology, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yu Chen
- Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Chaokun Li
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, 00014, Helsinki, Finland
| | - Ping Liu
- The State Key Laboratory of Chemical Resource Engineering, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yijie Zhang
- College of Life Science and Technology, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Weijie Yang
- College of Life Science and Technology, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Junfeng Jiang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Jianye Xia
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Shuobo Shi
- College of Life Science and Technology, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Tianwei Tan
- College of Life Science and Technology, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Jens Nielsen
- College of Life Science and Technology, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
- Department of Life Sciences, Chalmers University of Technology, SE412 96, Gothenburg, Sweden.
- BioInnovation Institute, Ole Maaløes Vej 3, DK2200, Copenhagen, Denmark.
| | - Yun Chen
- Department of Life Sciences, Chalmers University of Technology, SE412 96, Gothenburg, Sweden.
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kongens, Lyngby, Denmark.
| | - Zihe Liu
- College of Life Science and Technology, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
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Liu H, Sun Q, Ding Z, Shi W, Wang WH, Zhang C. Adenosine stimulates the basolateral 50 pS K + channel in renal proximal tubule via adenosine-A1 receptor. Front Physiol 2023; 14:1242975. [PMID: 37700760 PMCID: PMC10493268 DOI: 10.3389/fphys.2023.1242975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/14/2023] [Indexed: 09/14/2023] Open
Abstract
Background: The basolateral potassium channels play an important role in maintaining the membrane transport in the renal proximal tubules (PT) and adenosine receptors have been shown to regulate the trans-epithelial Na+ absorption in the PT. The aim of the present study is to explore whether adenosine also regulates the basolateral K+ channel of the PT and to determine the adenosine receptor type and the signaling pathway which mediates the effect of adenosine on the K+ channel. Methods: We have used the single channel recording to examine the basolateral K+ channel activity in the proximal tubules of the mouse kidney. All experiments were performed in cell-attached patches. Results: Single channel recording has detected a 50 pS inwardly-rectifying K+ channel with high channel open probability and this 50 pS K+ channel is a predominant type K+ channel in the basolateral membrane of the mouse PT. Adding adenosine increased 50 pS K+ channel activity in cell-attached patches, defined by NPo (a product of channel Numbers and Open Probability). The adenosine-induced stimulation of the 50 pS K+ channel was absent in the PT pretreated with DPCPX, a selective inhibitor of adenosine A1 receptor. In contrast, adenosine was still able to stimulate the 50 pS K+ channel in the PT pretreated with CP-66713, a selective adenosine A2 receptor antagonist. This suggests that the stimulatory effect of adenosine on the 50 pS K+ channel of the PT was mediated by adenosine-A1 receptor. Moreover, the effect of adenosine on the 50 pS K+ channel was blocked in the PT pretreated with U-73122 or Calphostin C, suggesting that adenosine-induced stimulation of the 50 pS K+ channels of the PT was due to the activation of phospholipase C (PLC) and protein kinase C (PKC) pathway. In contrast, the inhibition of phospholipase A2 (PLA2) with AACOCF3 or inhibition of protein kinase A (PKA) with H8 failed to block the adenosine-induced stimulation of the 50 pS K+ channel of the PT. Conclusion: We conclude that adenosine activates the 50 pS K+ channels in the basolateral membrane of PT via adenosine-A1 receptor. Furthermore, the effect of adenosine on the 50 pS K+ channel is mediated by PLC-PKC signaling pathway.
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Affiliation(s)
- Hao Liu
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | - Qi Sun
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | - Zheng Ding
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | - Wensen Shi
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, NY, United States
| | - Chengbiao Zhang
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
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Stepanova N. Oxalate Homeostasis in Non-Stone-Forming Chronic Kidney Disease: A Review of Key Findings and Perspectives. Biomedicines 2023; 11:1654. [PMID: 37371749 DOI: 10.3390/biomedicines11061654] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/03/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Chronic kidney disease (CKD) is a significant global public health concern associated with high morbidity and mortality rates. The maintenance of oxalate homeostasis plays a critical role in preserving kidney health, particularly in the context of CKD. Although the relationship between oxalate and kidney stone formation has been extensively investigated, our understanding of oxalate homeostasis in non-stone-forming CKD remains limited. This review aims to present an updated analysis of the existing literature, focusing on the intricate mechanisms involved in oxalate homeostasis in patients with CKD. Furthermore, it explores the key factors that influence oxalate accumulation and discusses the potential role of oxalate in CKD progression and prognosis. The review also emphasizes the significance of the gut-kidney axis in CKD oxalate homeostasis and provides an overview of current therapeutic strategies, as well as potential future approaches. By consolidating important findings and perspectives, this review offers a comprehensive understanding of the present knowledge in this field and identifies promising avenues for further research.
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Affiliation(s)
- Natalia Stepanova
- State Institution «Institute of Nephrology of the National Academy of Medical Sciences of Ukraine», 04050 Kyiv, Ukraine
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Li J, Huang S, Liu S, Liao X, Yan S, Liu Q. SLC26 family: a new insight for kidney stone disease. Front Physiol 2023; 14:1118342. [PMID: 37304821 PMCID: PMC10247987 DOI: 10.3389/fphys.2023.1118342] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 05/18/2023] [Indexed: 06/13/2023] Open
Abstract
The solute-linked carrier 26 (SLC26) protein family is comprised of multifunctional transporters of substrates that include oxalate, sulphate, and chloride. Disorders of oxalate homeostasis cause hyperoxalemia and hyperoxaluria, leading to urinary calcium oxalate precipitation and urolithogenesis. SLC26 proteins are aberrantly expressed during kidney stone formation, and consequently may present therapeutic targets. SLC26 protein inhibitors are in preclinical development. In this review, we integrate the findings of recent reports with clinical data to highlight the role of SLC26 proteins in oxalate metabolism during urolithogenesis, and discuss limitations of current studies and potential directions for future research.
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Affiliation(s)
- Jialin Li
- The First Clinical College, Gannan Medical University, Ganzhou, Jiangxi, China
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Sigen Huang
- The First Clinical College, Gannan Medical University, Ganzhou, Jiangxi, China
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Shengyin Liu
- The First Clinical College, Gannan Medical University, Ganzhou, Jiangxi, China
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Xinzhi Liao
- The First Clinical College, Gannan Medical University, Ganzhou, Jiangxi, China
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Sheng Yan
- The First Clinical College, Gannan Medical University, Ganzhou, Jiangxi, China
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Quanliang Liu
- Department of Urology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, China
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6
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Shi H, Ruan L, Chen Z, Liao Y, Wu W, Liu L, Xu X. Sulfur, sterol and trehalose metabolism in the deep-sea hydrocarbon seep tubeworm Lamellibrachia luymesi. BMC Genomics 2023; 24:175. [PMID: 37020304 PMCID: PMC10077716 DOI: 10.1186/s12864-023-09267-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 03/20/2023] [Indexed: 04/07/2023] Open
Abstract
BACKGROUND Lamellibrachia luymesi dominates cold sulfide-hydrocarbon seeps and is known for its ability to consume bacteria for energy. The symbiotic relationship between tubeworms and bacteria with particular adaptations to chemosynthetic environments has received attention. However, metabolic studies have primarily focused on the mechanisms and pathways of the bacterial symbionts, while studies on the animal hosts are limited. RESULTS Here, we sequenced the transcriptome of L. luymesi and generated a transcriptomic database containing 79,464 transcript sequences. Based on GO and KEGG annotations, we identified transcripts related to sulfur metabolism, sterol biosynthesis, trehalose synthesis, and hydrolysis. Our in-depth analysis identified sulfation pathways in L. luymesi, and sulfate activation might be an important detoxification pathway for promoting sulfur cycling, reducing byproducts of sulfide metabolism, and converting sulfur compounds to sulfur-containing organics, which are essential for symbiotic survival. Moreover, sulfide can serve directly as a sulfur source for cysteine synthesis in L. luymesi. The existence of two pathways for cysteine synthesis might ensure its participation in the formation of proteins, heavy metal detoxification, and the sulfide-binding function of haemoglobin. Furthermore, our data suggested that cold-seep tubeworm is capable of de novo sterol biosynthesis, as well as incorporation and transformation of cycloartenol and lanosterol into unconventional sterols, and the critical enzyme involved in this process might have properties similar to those in the enzymes from plants or fungi. Finally, trehalose synthesis in L. luymesi occurs via the trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP) pathways. The TPP gene has not been identified, whereas the TPS gene encodes a protein harbouring conserved TPS/OtsA and TPP/OtsB domains. The presence of multiple trehalases that catalyse trehalose hydrolysis could indicate the different roles of trehalase in cold-seep tubeworms. CONCLUSIONS We elucidated several molecular pathways of sulfate activation, cysteine and cholesterol synthesis, and trehalose metabolism. Contrary to the previous analysis, two pathways for cysteine synthesis and the cycloartenol-C-24-methyltransferase gene were identified in animals for the first time. The present study provides new insights into particular adaptations to chemosynthetic environments in L. luymesi and can serve as the basis for future molecular studies on host-symbiont interactions and biological evolution.
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Affiliation(s)
- Hong Shi
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources of Ministry of Natural Resources, Third Institute of Oceanography, Ministry of Natural Resources, Fujian Key Laboratory of Marine Genetic Resources, No. 178 Daxue Road, Xiamen, Fujian, 361005, People's Republic of China.
| | - Lingwei Ruan
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources of Ministry of Natural Resources, Third Institute of Oceanography, Ministry of Natural Resources, Fujian Key Laboratory of Marine Genetic Resources, No. 178 Daxue Road, Xiamen, Fujian, 361005, People's Republic of China.
- College of Marine Biology, Xiamen ocean vocational college, 361100, Xiamen, People's Republic of China.
- Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang, 222005, People's Republic of China.
| | - Zimeng Chen
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources of Ministry of Natural Resources, Third Institute of Oceanography, Ministry of Natural Resources, Fujian Key Laboratory of Marine Genetic Resources, No. 178 Daxue Road, Xiamen, Fujian, 361005, People's Republic of China
| | - Yifei Liao
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources of Ministry of Natural Resources, Third Institute of Oceanography, Ministry of Natural Resources, Fujian Key Laboratory of Marine Genetic Resources, No. 178 Daxue Road, Xiamen, Fujian, 361005, People's Republic of China
- School of Advanced Manufacturing, Fuzhou University, Fuzhou, 362200, People's Republic of China
| | - Wenhao Wu
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources of Ministry of Natural Resources, Third Institute of Oceanography, Ministry of Natural Resources, Fujian Key Laboratory of Marine Genetic Resources, No. 178 Daxue Road, Xiamen, Fujian, 361005, People's Republic of China
- Department of Biology and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, People's Republic of China
| | - Linmin Liu
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources of Ministry of Natural Resources, Third Institute of Oceanography, Ministry of Natural Resources, Fujian Key Laboratory of Marine Genetic Resources, No. 178 Daxue Road, Xiamen, Fujian, 361005, People's Republic of China
| | - Xun Xu
- State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources of Ministry of Natural Resources, Third Institute of Oceanography, Ministry of Natural Resources, Fujian Key Laboratory of Marine Genetic Resources, No. 178 Daxue Road, Xiamen, Fujian, 361005, People's Republic of China
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7
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Shin S, Boadi EA, Bandyopadhyay BC. Ablation of TRPC3 compromises bicarbonate and phosphate transporter activity in mice proximal tubular cells. Clin Exp Pharmacol Physiol 2023; 50:247-255. [PMID: 36433745 PMCID: PMC10258833 DOI: 10.1111/1440-1681.13741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 11/19/2022] [Accepted: 11/21/2022] [Indexed: 11/28/2022]
Abstract
Proximal tubular (PT) cells reabsorb most calcium (Ca2+ ), phosphate (PO4 3- ), bicarbonate (HCO3 - ), and oxalate (C2 O4 2- ) ions. We have shown that mice lacking Transient Receptor Potential Canonical 3 (TRPC3-/- ) channel are moderately hypercalciuric with presentation of luminal calcium phosphate (CaP) crystals at the loop of Henle (LOH). However, other predisposing factors for such crystal deposition are unknown. Thus, we examined the distinctions in functional status of HCO3 - , PO4 3- , and C2 O4 2- transporters in PT cells of wild type (WT) and TRPC3-/- mice by whole-cell patch clamp techniques to assess their contribution in the development of LOH CaP crystals. Here we show the development of concentration dependent HCO3 - -induced currents in all PT cells, which was confirmed by using specific HCO3 - channel inhibitor, S0859. Interestingly, such activities were diminished in PT cells from TRPC3-/- mice, suggesting reduced HCO3 - transport in absence of TRPC3. While PO4 3- -induced currents were also concentration dependent in all PT cells (confirmed by PO4 3- channel inhibitor, PF-06869206), those activities were reduced in absence of TRPC3, suggesting lower PO4 3- reabsorption that can leave excess luminal PO4 3- . Next, we applied thiosulfate (O3 S2 2 - ) as a competitive inhibitor of the SLC26a6 transporter upon C2 O4 2- current activation and observed a reduced C2 O4 2- -induced conductance which was greater in TRPC3-/- PT cells. Together, these results suggest that the reduced activities of HCO3 - , PO4 3- , and C2 O4 2- transporters in moderately hypercalciuric (TRPC3-/- ) PT cells can create a predisposing condition for CaP and CaP tubular crystallization, enabling CaP crystal formation in LOH of TRPC3-/- mice.
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Affiliation(s)
- Samuel Shin
- Calcium Signaling Laboratory, Research Service, Veterans Affairs Medical Center, Washington, Columbia, USA
| | - Eugenia Awuah Boadi
- Calcium Signaling Laboratory, Research Service, Veterans Affairs Medical Center, Washington, Columbia, USA
| | - Bidhan C. Bandyopadhyay
- Calcium Signaling Laboratory, Research Service, Veterans Affairs Medical Center, Washington, Columbia, USA
- Division of Renal Diseases & Hypertension, Department of Medicine, The George Washington University, Washington, Columbia, USA
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8
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Sinha M, Zabini D, Guntur D, Nagaraj C, Enyedi P, Olschewski H, Kuebler WM, Olschewski A. Chloride channels in the lung: Challenges and perspectives for viral infections, pulmonary arterial hypertension, and cystic fibrosis. Pharmacol Ther 2022; 237:108249. [PMID: 35878810 DOI: 10.1016/j.pharmthera.2022.108249] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/06/2022] [Accepted: 07/11/2022] [Indexed: 10/16/2022]
Abstract
Fine control over chloride homeostasis in the lung is required to maintain membrane excitability, transepithelial transport as well as intra- and extracellular ion and water homeostasis. Over the last decades, a growing number of chloride channels and transporters have been identified in the cells of the pulmonary vasculature and the respiratory tract. The importance of these proteins is underpinned by the fact that impairment of their physiological function is associated with functional dysregulation, structural remodeling, or hereditary diseases of the lung. This paper reviews the field of chloride channels and transporters in the lung and discusses chloride channels in disease processes such as viral infections including SARS-CoV- 2, pulmonary arterial hypertension, cystic fibrosis and asthma. Although chloride channels have become a hot research topic in recent years, remarkably few of them have been targeted by pharmacological agents. As such, we complement the putative pathophysiological role of chloride channels here with a summary of their therapeutic potential.
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Affiliation(s)
- Madhushri Sinha
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 5, 8036 Graz, Austria.
| | - Diana Zabini
- Department of Physiology, Neue Stiftingtalstrasse 6/V, 8010 Graz, Austria.
| | - Divya Guntur
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 5, 8036 Graz, Austria.
| | - Chandran Nagaraj
- Ludwig Boltzmann Institute for Lung Vascular Research, Neue Stiftingtalstraße 6, 8010 Graz, Austria.
| | - Peter Enyedi
- Department of Physiology, Semmelweis University, Tűzoltó utca 37-47, 1094 Budapest, Hungary.
| | - Horst Olschewski
- Department of Internal Medicine, Division of Pulmonology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria.
| | - Wolfgang M Kuebler
- Institute of Physiology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
| | - Andrea Olschewski
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 5, 8036 Graz, Austria; Ludwig Boltzmann Institute for Lung Vascular Research, Neue Stiftingtalstraße 6, 8010 Graz, Austria.
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9
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Xu J, Barone S, Varasteh Kia M, Holliday LS, Zahedi K, Soleimani M. Identification of IQGAP1 as a SLC26A4 (Pendrin)-Binding Protein in the Kidney. Front Mol Biosci 2022; 9:874186. [PMID: 35601831 PMCID: PMC9117723 DOI: 10.3389/fmolb.2022.874186] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/22/2022] [Indexed: 11/25/2022] Open
Abstract
Background: Several members of the SLC26A family of transporters, including SLC26A3 (DRA), SLC26A5 (prestin), SLC26A6 (PAT-1; CFEX) and SLC26A9, form multi-protein complexes with a number of molecules (e.g., cytoskeletal proteins, anchoring or adaptor proteins, cystic fibrosis transmembrane conductance regulator, and protein kinases). These interactions provide regulatory signals for these molecules. However, the identity of proteins that interact with the Cl-/HCO3 - exchanger, SLC26A4 (pendrin), have yet to be determined. The purpose of this study is to identify the protein(s) that interact with pendrin. Methods: A yeast two hybrid (Y2H) system was employed to screen a mouse kidney cDNA library using the C-terminal fragment of SLC26A4 as bait. Immunofluorescence microscopic examination of kidney sections, as well as co-immunoprecipitation assays, were performed using affinity purified antibodies and kidney protein extracts to confirm the co-localization and interaction of pendrin and the identified binding partners. Co-expression studies were carried out in cultured cells to examine the effect of binding partners on pendrin trafficking and activity. Results: The Y2H studies identified IQ motif-containing GTPase-activating protein 1 (IQGAP1) as a protein that binds to SLC26A4's C-terminus. Co-immunoprecipitation experiments using affinity purified anti-IQGAP1 antibodies followed by western blot analysis of kidney protein eluates using pendrin-specific antibodies confirmed the interaction of pendrin and IQGAP1. Immunofluorescence microscopy studies demonstrated that IQGAP1 co-localizes with pendrin on the apical membrane of B-intercalated cells, whereas it shows basolateral expression in A-intercalated cells in the cortical collecting duct (CCD). Functional and confocal studies in HEK-293 cells, as well as confocal studies in MDCK cells, demonstrated that the co-transfection of pendrin and IQGAP1 shows strong co-localization of the two molecules on the plasma membrane along with enhanced Cl-/HCO3 - exchanger activity. Conclusion: IQGAP1 was identified as a protein that binds to the C-terminus of pendrin in B-intercalated cells. IQGAP1 co-localized with pendrin on the apical membrane of B-intercalated cells. Co-expression of IQGAP1 with pendrin resulted in strong co-localization of the two molecules and increased the activity of pendrin in the plasma membrane in cultured cells. We propose that pendrin's interaction with IQGAP1 may play a critical role in the regulation of CCD function and physiology, and that disruption of this interaction could contribute to altered pendrin trafficking and/or activity in pathophysiologic states.
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Affiliation(s)
- Jie Xu
- Research Services, VA Medical Center, Albuquerque, NM, United States,Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
| | - Sharon Barone
- Research Services, VA Medical Center, Albuquerque, NM, United States,Department of Medicine, University of Cincinnati, Cincinnati, OH, United States,Department of Medicine, University of New Mexico, Albuquerque, NM, United States
| | - Mujan Varasteh Kia
- Department of Medicine, University of Cincinnati, Cincinnati, OH, United States
| | - L. Shannon Holliday
- Department of Orthodontics, University of Florida, Gainesville, FL, United States
| | - Kamyar Zahedi
- Research Services, VA Medical Center, Albuquerque, NM, United States,Department of Medicine, University of Cincinnati, Cincinnati, OH, United States,Department of Medicine, University of New Mexico, Albuquerque, NM, United States
| | - Manoocher Soleimani
- Research Services, VA Medical Center, Albuquerque, NM, United States,Department of Medicine, University of Cincinnati, Cincinnati, OH, United States,Department of Medicine, University of New Mexico, Albuquerque, NM, United States,*Correspondence: Manoocher Soleimani,
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10
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Remigante A, Spinelli S, Pusch M, Sarikas A, Morabito R, Marino A, Dossena S. Role of SLC4 and SLC26 solute carriers during oxidative stress. Acta Physiol (Oxf) 2022; 235:e13796. [PMID: 35143116 PMCID: PMC9542443 DOI: 10.1111/apha.13796] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 12/13/2022]
Abstract
Bicarbonate is one of the major anions in mammalian tissues and fluids, is utilized by various exchangers to transport other ions and organic substrates across cell membranes and plays a critical role in cell and systemic pH homoeostasis. Chloride/bicarbonate (Cl−/HCO3−) exchangers are abundantly expressed in erythrocytes and epithelial cells and, as a consequence, are particularly exposed to oxidants in the systemic circulation and at the interface with the external environment. Here, we review the physiological functions and pathophysiological alterations of Cl−/HCO3− exchangers belonging to the solute carriers SLC4 and SLC26 superfamilies in relation to oxidative stress. Particularly well studied is the impact of oxidative stress on the red blood cell SLC4A1/AE1 (Band 3 protein), of which the function seems to be directly affected by oxidative stress and possibly involves oxidation of the transporter itself or its interacting proteins, with detrimental consequences in oxidative stress‐related diseases including inflammation, metabolic dysfunctions and ageing. The effect of oxidative stress on SLC26 members was less extensively explored. Indirect evidence suggests that SLC26 transporters can be target as well as determinants of oxidative stress, especially when their expression is abolished or dysregulated.
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Affiliation(s)
- Alessia Remigante
- Biophysics Institute National Research Council Genova Italy
- Department of Chemical Biological, Pharmaceutical and Environmental Sciences University of Messina Messina Italy
| | - Sara Spinelli
- Department of Chemical Biological, Pharmaceutical and Environmental Sciences University of Messina Messina Italy
| | - Michael Pusch
- Biophysics Institute National Research Council Genova Italy
| | - Antonio Sarikas
- Institute of Pharmacology and Toxicology Paracelsus Medical University Salzburg Austria
| | - Rossana Morabito
- Department of Chemical Biological, Pharmaceutical and Environmental Sciences University of Messina Messina Italy
| | - Angela Marino
- Department of Chemical Biological, Pharmaceutical and Environmental Sciences University of Messina Messina Italy
| | - Silvia Dossena
- Institute of Pharmacology and Toxicology Paracelsus Medical University Salzburg Austria
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11
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Huang JL, Mo ZY, Li ZY, Liang GY, Liu HL, Aschner M, Ou SY, Zhou B, Chen ZM, Jiang YM. Association of lead and cadmium exposure with kidney stone incidence: A study on the non-occupational population in Nandan of China. J Trace Elem Med Biol 2021; 68:126852. [PMID: 34508950 DOI: 10.1016/j.jtemb.2021.126852] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 08/16/2021] [Accepted: 08/24/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Environmental lead (Pb) and cadmium (Cd) pollution has been considered a risk factor in the etiology of kidney stones. However, the association between Pb and Cd exposure and kidney stone incidence has yet to be determined. OBJECTIVES This study aimed to determine a possible the association between kidney stones with Pb and Cd exposure (alone or combined) in a non-occupational population. METHODS Pb and Cd contaminations in soil-plant system were determined by flame atomic absorption spectrophotometry. Health risk assessment of dietary Pb or Cd intake from rice and vegetables were calculated. Kidney stones were diagnosed with urinary tract ultrasonography. Urinary cadmium (UCd) and blood lead (BPb) levels were determined by graphite-furnace atomic absorption spectrometry. Multivariate logistic regression models were constructed. RESULTS The hazard indexes (HI) of Pb and Cd were 7.91 and 7.31. The odds ratio (OR) was 2.83 (95 %CI:1.38-5.77) in males with high BPb (BPb ≥ 100 μg/L), compared with those with low BPb (BPb<100 μg/L). Compared to those with low BPb and low UCd (BPb<100 μg/L and UCd<2 μg/g creatinine), the ORs were 2.58 (95 % CI:1.17-5.70) and 3.43 (95 % CI:1.21-9.16) in females and males with high BPb and high UCd (BPb ≥100 μg/L and UCd ≥2 μg/g creatinine), respectively. The OR was 3.16 (95 % CI:1.26-7.88) in males with high BPb and low UCd (BPb ≥ 100 μg/L and UCd <2 μg/g creatinine), compared to those with low BPb and low UCd. CONCLUSIONS Kidney stones incidence was increased by high Pb exposure in males, and by Pb and Cd co-exposure in males and females.
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Affiliation(s)
- Jiong-Li Huang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, 530021, China; Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, Guangxi Medical University, Nanning, 530021, China; Atmospheric Environment Research Center, Scientific Research Academy of Guangxi Environmental Protection, Nanning, 530022, China
| | - Zhao-Yu Mo
- Atmospheric Environment Research Center, Scientific Research Academy of Guangxi Environmental Protection, Nanning, 530022, China; Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Zhong-You Li
- Department of Preventive Medicine, School of Public Health and Management, Guangxi University of Chinese Medicine, Nanning, 530200, China
| | - Gui-Yun Liang
- Atmospheric Environment Research Center, Scientific Research Academy of Guangxi Environmental Protection, Nanning, 530022, China
| | - Hui-Lin Liu
- Atmospheric Environment Research Center, Scientific Research Academy of Guangxi Environmental Protection, Nanning, 530022, China
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, United States
| | - Shi-Yan Ou
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, 530021, China; Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, Guangxi Medical University, Nanning, 530021, China
| | - Bin Zhou
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Zhi-Ming Chen
- Atmospheric Environment Research Center, Scientific Research Academy of Guangxi Environmental Protection, Nanning, 530022, China.
| | - Yue-Ming Jiang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, 530021, China; Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, Guangxi Medical University, Nanning, 530021, China.
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12
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Sun H, Paudel O, Sham JSK. Increased intracellular Cl - concentration in pulmonary arterial myocytes is associated with chronic hypoxic pulmonary hypertension. Am J Physiol Cell Physiol 2021; 321:C297-C307. [PMID: 34161154 DOI: 10.1152/ajpcell.00172.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chloride channels play an important role in regulating smooth muscle contraction and proliferation, and contribute to the enhanced constriction of pulmonary arteries (PAs) in pulmonary hypertension (PH). The intracellular Cl- concentration ([Cl-]i), tightly regulated by various Cl- transporters, determines the driving force for Cl- conductance, thereby the functional outcome of Cl- channel activation. This study characterizes for the first time the expression profile of Cl- transporters/exchangers in PA smooth muscle and provides the first evidence that the intracellular Cl- homeostasis is altered in PA smooth muscle cells (PASMCs) associated with chronic hypoxic PH (CHPH). Quantitative RT-PCR revealed that the endothelium-denuded intralobar PA of rats expressed Slc12a gene family-encoded Na-K-2Cl cotransporter 1 (NKCC1), K-Cl cotransporters (KCC) 1, 3, and 4, and Slc4a gene family-encoded Na+-independent and Na+-dependent Cl-/HCO3- exchangers. Exposure of rats to chronic hypoxia (10% O2, 3 wk) caused CHPH and selectively increased the expression of Cl--accumulating NKCC1 and reduced the Cl--extruding KCC4. The intracellular Cl- concentration ([Cl-]i) averaged at 45 mM and 47 mM in normoxic PASMCs as determined by fluorescent indicator MEQ and by gramicidin-perforated patch-clamp technique, respectively. The ([Cl-]i was increased by ∼10 mM in PASMCs of rats with CHPH. Future studies are warranted to further establish the hypothesis that the altered intracellular Cl- homeostasis contributes to the pathogenesis of CHPH.
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Affiliation(s)
- Hui Sun
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Division of Allergy and Clinical Immunology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Omkar Paudel
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - James S K Sham
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
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13
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Pizzagalli MD, Bensimon A, Superti‐Furga G. A guide to plasma membrane solute carrier proteins. FEBS J 2021; 288:2784-2835. [PMID: 32810346 PMCID: PMC8246967 DOI: 10.1111/febs.15531] [Citation(s) in RCA: 159] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/07/2020] [Accepted: 08/17/2020] [Indexed: 12/13/2022]
Abstract
This review aims to serve as an introduction to the solute carrier proteins (SLC) superfamily of transporter proteins and their roles in human cells. The SLC superfamily currently includes 458 transport proteins in 65 families that carry a wide variety of substances across cellular membranes. While members of this superfamily are found throughout cellular organelles, this review focuses on transporters expressed at the plasma membrane. At the cell surface, SLC proteins may be viewed as gatekeepers of the cellular milieu, dynamically responding to different metabolic states. With altered metabolism being one of the hallmarks of cancer, we also briefly review the roles that surface SLC proteins play in the development and progression of cancer through their influence on regulating metabolism and environmental conditions.
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Affiliation(s)
- Mattia D. Pizzagalli
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Ariel Bensimon
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Giulio Superti‐Furga
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
- Center for Physiology and PharmacologyMedical University of ViennaAustria
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14
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Berg P, Svendsen SL, Hoang TTL, Praetorius HA, Sorensen MV, Leipziger J. Impaired renal HCO 3 - secretion in CFTR deficient mice causes metabolic alkalosis during chronic base-loading. Acta Physiol (Oxf) 2021; 231:e13591. [PMID: 33270356 DOI: 10.1111/apha.13591] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 11/27/2020] [Accepted: 11/27/2020] [Indexed: 12/11/2022]
Abstract
AIM Cystic fibrosis patients have an increased risk of developing metabolic alkalosis presumably as a result of altered renal HCO3 - handling. In this study, we directly assess the kidneys' ability to compensate for a chronic base-load in the absence of functional CFTR. METHODS Comprehensive urine and blood acid-base analyses were done in anaesthetized WT mice or mice lacking either CFTR or pendrin, with or without 7 days of oral NaHCO3 loading. The in vivo experiments were complemented by a combination of immunoblotting and experiments with perfused isolated mouse cortical collecting ducts (CCD). RESULTS Base-loaded WT mice maintained acid-base homeostasis by elevating urinary pH and HCO3 - excretion and decreasing urinary net acid excretion. In contrast, pendrin KO mice and CFTR KO mice were unable to increase urinary pH and HCO3 - excretion and unable to decrease urinary net acid excretion sufficiently and thus developed metabolic alkalosis in response to the same base-load. The expression of pendrin was increased in response to the base-load in WT mice with a paralleled increased pendrin function in the perfused CCD. In CFTR KO mice, 7 days of base-loading did not upregulate pendrin expression and apical Cl- /HCO3 - exchange function was strongly blunted in the CCD. CONCLUSION CFTR KO mice develop metabolic alkalosis during a chronic base-load because they are unable to sufficiently elevate renal HCO3 - excretion. This can be explained by markedly reduced pendrin function in the absence of CFTR.
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Affiliation(s)
- Peder Berg
- Department of Biomedicine, Physiology Faculty of Health Aarhus University Aarhus C Denmark
| | - Samuel L. Svendsen
- Department of Biomedicine, Physiology Faculty of Health Aarhus University Aarhus C Denmark
| | - Thi Thuy Linh Hoang
- Department of Biomedicine, Physiology Faculty of Health Aarhus University Aarhus C Denmark
| | - Helle A. Praetorius
- Department of Biomedicine, Physiology Faculty of Health Aarhus University Aarhus C Denmark
| | - Mads V. Sorensen
- Department of Biomedicine, Physiology Faculty of Health Aarhus University Aarhus C Denmark
| | - Jens Leipziger
- Department of Biomedicine, Physiology Faculty of Health Aarhus University Aarhus C Denmark
- Aarhus Institute of Advanced Studies Aarhus University Aarhus C Denmark
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15
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One-carbon metabolism in cancer cells: a critical review based on a core model of central metabolism. Biochem Soc Trans 2021; 49:1-15. [PMID: 33616629 DOI: 10.1042/bst20190008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 01/19/2021] [Accepted: 01/26/2021] [Indexed: 12/25/2022]
Abstract
One-carbon metabolism (1C-metabolism), also called folate metabolism because the carbon group is attached to folate-derived tetrahydrofolate, is crucial in metabolism. It is at the heart of several essential syntheses, particularly those of purine and thymidylate. After a short reminder of the organization of 1C-metabolism, I list its salient features as reported in the literature. Then, using flux balance analysis, a core model of central metabolism and the flux constraints for an 'average cancer cell metabolism', I explore the fundamentals underlying 1C-metabolism and its relationships with the rest of metabolism. Some unreported properties of 1C-metabolism emerge, such as its potential roles in mitochondrial NADH exchange with cytosolic NADPH, participation in NADH recycling, and optimization of cell proliferation.
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16
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Trampert DC, van de Graaf SFJ, Jongejan A, Oude Elferink RPJ, Beuers U. Hepatobiliary acid-base homeostasis: Insights from analogous secretory epithelia. J Hepatol 2021; 74:428-441. [PMID: 33342564 DOI: 10.1016/j.jhep.2020.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/03/2020] [Accepted: 10/19/2020] [Indexed: 12/14/2022]
Abstract
Many epithelia secrete bicarbonate-rich fluid to generate flow, alter viscosity, control pH and potentially protect luminal and intracellular structures from chemical stress. Bicarbonate is a key component of human bile and impaired biliary bicarbonate secretion is associated with liver damage. Major efforts have been undertaken to gain insight into acid-base homeostasis in cholangiocytes and more can be learned from analogous secretory epithelia. Extrahepatic examples include salivary and pancreatic duct cells, duodenocytes, airway and renal epithelial cells. The cellular machinery involved in acid-base homeostasis includes carbonic anhydrase enzymes, transporters of the solute carrier family, and intra- and extracellular pH sensors. This pH-regulatory system is orchestrated by protein-protein interactions, the establishment of an electrochemical gradient across the plasma membrane and bicarbonate sensing of the intra- and extracellular compartment. In this review, we discuss conserved principles identified in analogous secretory epithelia in the light of current knowledge on cholangiocyte physiology. We present a framework for cholangiocellular acid-base homeostasis supported by expression analysis of publicly available single-cell RNA sequencing datasets from human cholangiocytes, which provide insights into the molecular basis of pH homeostasis and dysregulation in the biliary system.
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Affiliation(s)
- David C Trampert
- Amsterdam UMC, University of Amsterdam, Department of Gastroenterology and Hepatology, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology Endocrinology Metabolism (AGEM), Meibergdreef 9, Amsterdam, the Netherlands
| | - Stan F J van de Graaf
- Amsterdam UMC, University of Amsterdam, Department of Gastroenterology and Hepatology, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology Endocrinology Metabolism (AGEM), Meibergdreef 9, Amsterdam, the Netherlands
| | - Aldo Jongejan
- Amsterdam UMC, University of Amsterdam, Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Meibergdreef 9, Amsterdam, the Netherlands
| | - Ronald P J Oude Elferink
- Amsterdam UMC, University of Amsterdam, Department of Gastroenterology and Hepatology, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology Endocrinology Metabolism (AGEM), Meibergdreef 9, Amsterdam, the Netherlands
| | - Ulrich Beuers
- Amsterdam UMC, University of Amsterdam, Department of Gastroenterology and Hepatology, Tytgat Institute for Liver and Intestinal Research, Amsterdam Gastroenterology Endocrinology Metabolism (AGEM), Meibergdreef 9, Amsterdam, the Netherlands.
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17
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Klaerner G, Shao J, Biyani K, Kade M, Kierstead P, Gbur R, Tabakman S, Nguyen S, Buysse J. Mechanism of Action of Veverimer: A Novel, Orally Administered, Nonabsorbed, Counterion-Free, Hydrochloric Acid Binder under Development for the Treatment of Metabolic Acidosis in Chronic Kidney Disease. J Pharmacol Exp Ther 2020; 375:439-450. [PMID: 33033169 DOI: 10.1124/jpet.120.000190] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 08/31/2020] [Indexed: 12/14/2022] Open
Abstract
Current management of metabolic acidosis in patients with chronic kidney disease (CKD) relies on dietary intervention to reduce daily endogenous acid production or neutralization of retained acid with oral alkali (sodium bicarbonate, sodium citrate). Veverimer is being developed as a novel oral treatment for metabolic acidosis through removal of intestinal acid, resulting in an increase in serum bicarbonate. Veverimer is a free-amine polymer that combines high capacity and selectivity to bind and remove hydrochloric acid (HCl) from the gastrointestinal (GI) tract. In vitro studies demonstrated that veverimer had a binding capacity of 10.7 ± 0.4 mmol HCl per gram of polymer with significant binding capacity (>5 mmol/g) across the range of pH values found in the human GI tract (1.5-7). Upon protonation, veverimer bound chloride with high specificity but showed little or no binding of phosphate, citrate, or taurocholate (<1.5 mmol/g), which are all anions commonly found in the human GI tract. Administration of veverimer to rats with adenine-induced CKD and metabolic acidosis resulted in a significant increase in fecal chloride excretion and a dose-dependent increase in serum bicarbonate to within the normal range compared with untreated controls. Absorption, distribution, metabolism, and excretion studies in rats and dogs dosed with 14C-labeled veverimer showed that the polymer was not absorbed from the GI tract and was quantitatively eliminated in the feces. Acid removal by veverimer, an orally administered, nonabsorbed polymer, may provide a potential new treatment for metabolic acidosis in patients with CKD. SIGNIFICANCE STATEMENT: Metabolic acidosis is a complication of chronic kidney disease (CKD) as well as a cause of CKD progression. Veverimer is a high-capacity, selective, nonabsorbed, hydrochloric acid-binding polymer being developed as a treatment for metabolic acidosis. Veverimer binds and removes hydrochloric acid from the gastrointestinal tract, resulting in increased serum bicarbonate and the correction of metabolic acidosis. Veverimer is not an ion-exchange resin and does not deliver sodium or other counterions, and so it may be appropriate for patients with CKD with and without sodium-sensitive comorbidities.
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Affiliation(s)
- Gerrit Klaerner
- Tricida, Inc., South San Francisco, California (G.K., J.S., K.B., M.K., P.K., R.G., S.T., S.N.) and FFV Consulting, Los Altos, California (J.B.)
| | - Jun Shao
- Tricida, Inc., South San Francisco, California (G.K., J.S., K.B., M.K., P.K., R.G., S.T., S.N.) and FFV Consulting, Los Altos, California (J.B.)
| | - Kalpesh Biyani
- Tricida, Inc., South San Francisco, California (G.K., J.S., K.B., M.K., P.K., R.G., S.T., S.N.) and FFV Consulting, Los Altos, California (J.B.)
| | - Matthew Kade
- Tricida, Inc., South San Francisco, California (G.K., J.S., K.B., M.K., P.K., R.G., S.T., S.N.) and FFV Consulting, Los Altos, California (J.B.)
| | - Paul Kierstead
- Tricida, Inc., South San Francisco, California (G.K., J.S., K.B., M.K., P.K., R.G., S.T., S.N.) and FFV Consulting, Los Altos, California (J.B.)
| | - Randi Gbur
- Tricida, Inc., South San Francisco, California (G.K., J.S., K.B., M.K., P.K., R.G., S.T., S.N.) and FFV Consulting, Los Altos, California (J.B.)
| | - Scott Tabakman
- Tricida, Inc., South San Francisco, California (G.K., J.S., K.B., M.K., P.K., R.G., S.T., S.N.) and FFV Consulting, Los Altos, California (J.B.)
| | - Son Nguyen
- Tricida, Inc., South San Francisco, California (G.K., J.S., K.B., M.K., P.K., R.G., S.T., S.N.) and FFV Consulting, Los Altos, California (J.B.)
| | - Jerry Buysse
- Tricida, Inc., South San Francisco, California (G.K., J.S., K.B., M.K., P.K., R.G., S.T., S.N.) and FFV Consulting, Los Altos, California (J.B.)
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18
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Abstract
Metabolic alkalosis is a very commonly encountered acid-base disorder that may be generated by a variety of exogenous and/or endogenous, pathophysiologic mechanisms. Multiple mechanisms are also responsible for the persistence, or maintenance, of metabolic alkalosis. Understanding these generation and maintenance mechanisms helps direct appropriate intervention and correction of this disorder. The framework utilized in this review is based on the ECF volume-centered approach popularized by Donald Seldin and Floyd Rector in the 1970s. Although many subsequent scientific discoveries have advanced our understanding of the pathophysiology of metabolic alkalosis, that framework continues to be a valuable and relatively straightforward diagnostic and therapeutic model.
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Affiliation(s)
- Michael Emmett
- Divisions of Internal Medicine and Nephrology, Department of Medicine, Baylor University Medical Center at Dallas, Dallas, Texas
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19
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Lopes FM, Roberts NA, Zeef LAH, Gardiner NJ, Woolf AS. Overactivity or blockade of transforming growth factor-β each generate a specific ureter malformation. J Pathol 2019; 249:472-484. [PMID: 31400222 PMCID: PMC6900140 DOI: 10.1002/path.5335] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 07/19/2019] [Accepted: 08/06/2019] [Indexed: 12/13/2022]
Abstract
Transforming growth factor-β (TGFβ) has been reported to be dysregulated in malformed ureters. There exists, however, little information on whether altered TGFβ levels actually perturb ureter development. We therefore hypothesised that TGFβ has functional effects on ureter morphogenesis. Tgfb1, Tgfb2 and Tgfb3 transcripts coding for TGFβ ligands, as well as Tgfbr1 and Tgfbr2 coding for TGFβ receptors, were detected by quantitative polymerase chain reaction in embryonic mouse ureters collected over a wide range of stages. As assessed by in situ hybridisation and immunohistochemistry, the two receptors were detected in embryonic urothelia. Next, TGFβ1 was added to serum-free cultures of embryonic day 15 mouse ureters. These organs contain immature smooth muscle and urothelial layers and their in vivo potential to grow and acquire peristaltic function can be replicated in serum-free organ culture. Such organs therefore constitute a suitable developmental stage with which to define roles of factors that affect ureter growth and functional differentiation. Exogenous TGFβ1 inhibited growth of the ureter tube and generated cocoon-like dysmorphogenesis. RNA sequencing suggested that altered levels of transcripts encoding certain fibroblast growth factors (FGFs) followed exposure to TGFβ. In serum-free organ culture exogenous FGF10 but not FGF18 abrogated certain dysmorphic effects mediated by exogenous TGFβ1. To assess whether an endogenous TGFβ axis functions in developing ureters, embryonic day 15 explants were exposed to TGFβ receptor chemical blockade; growth of the ureter was enhanced, and aberrant bud-like structures arose from the urothelial tube. The muscle layer was attenuated around these buds, and peristalsis was compromised. To determine whether TGFβ effects were limited to one stage, explants of mouse embryonic day 13 ureters, more primitive organs, were exposed to exogenous TGFβ1, again generating cocoon-like structures, and to TGFβ receptor blockade, again generating ectopic buds. As for the mouse studies, immunostaining of normal embryonic human ureters detected TGFβRI and TGFβRII in urothelia. Collectively, these observations reveal unsuspected regulatory roles for endogenous TGFβ in embryonic ureters, fine-tuning morphogenesis and functional differentiation. Our results also support the hypothesis that the TGFβ up-regulation reported in ureter malformations impacts on pathobiology. Further experiments are needed to unravel the intracellular signalling mechanisms involved in these dysmorphic responses. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Filipa M Lopes
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and HealthUniversity of ManchesterManchesterUK
| | - Neil A Roberts
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and HealthUniversity of ManchesterManchesterUK
| | - Leo AH Zeef
- The Bioinformatics Core FacilityUniversity of ManchesterManchesterUK
| | - Natalie J Gardiner
- Division of Diabetes, Endocrinology and Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - Adrian S Woolf
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and HealthUniversity of ManchesterManchesterUK
- Royal Manchester Children's HospitalManchester University NHS Foundation Trust, Manchester Academic Health Science CentreManchesterUK
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20
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Ishii J, Suzuki A, Kimura T, Tateyama M, Tanaka T, Yazawa T, Arimasu Y, Chen IS, Aoyama K, Kubo Y, Saitoh S, Mizuno H, Kamma H. Congenital goitrous hypothyroidism is caused by dysfunction of the iodide transporter SLC26A7. Commun Biol 2019; 2:270. [PMID: 31372509 PMCID: PMC6656751 DOI: 10.1038/s42003-019-0503-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 06/13/2019] [Indexed: 12/27/2022] Open
Abstract
Iodide transport and storage in the thyroid follicles is crucial for thyroid hormone synthesis. Pendrin, the iodide exporter that transports iodide to thyroid follicles, is responsible for Pendred syndrome, a disorder characterized by congenital hypothyroidism and hearing loss. However, thyroid hormone levels are basically normal in patients with Pendred syndrome, indicating the presence of another unknown iodide transporter. Here, we show that SLC26A7 is a novel iodide transporter in the thyroid. We observe that SLC26A7 is specifically expressed in normal thyroid tissues and demonstrate its function in iodide transport. Using whole-exome sequencing, we also find a homozygous nonsense mutation in SLC26A7 (c.1498 C > T; p.Gln500Ter) in two siblings with congenital goitrous hypothyroidism. The mutated SLC26A7 protein shows an abnormal cytoplasmic localisation and lacks the iodide transport function. These results reveal that SLC26A7 functions as a novel iodide transporter in the thyroid and its dysfunction affects thyroid hormonogenesis in humans and causes congenital goitrous hypothyroidism.
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Affiliation(s)
- Jun Ishii
- Department of Pathology, Kyorin University School of Medicine, Tokyo, Japan
- Department of Pathology, Dokkyo Medical University, Tochigi, Japan
| | - Atsushi Suzuki
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Toru Kimura
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo, Japan
| | - Michihiro Tateyama
- Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, Okazaki, Japan
| | - Tatsushi Tanaka
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Takuya Yazawa
- Department of Pathology, Dokkyo Medical University, Tochigi, Japan
| | - Yu Arimasu
- Department of Pathology, Kyorin University School of Medicine, Tokyo, Japan
| | - I-Shan Chen
- Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, Okazaki, Japan
| | - Kohei Aoyama
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Yoshihiro Kubo
- Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, Okazaki, Japan
| | - Shinji Saitoh
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Haruo Mizuno
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
- Department of Pediatrics, International University of Health and Welfare, School of Medicine, Narita, Japan
| | - Hiroshi Kamma
- Department of Pathology, Kyorin University School of Medicine, Tokyo, Japan
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21
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Ramesh K, Yarra T, Clark MS, John U, Melzner F. Expression of calcification-related ion transporters during blue mussel larval development. Ecol Evol 2019; 9:7157-7172. [PMID: 31380040 PMCID: PMC6662379 DOI: 10.1002/ece3.5287] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 05/06/2019] [Accepted: 05/08/2019] [Indexed: 01/03/2023] Open
Abstract
The physiological processes driving the rapid rates of calcification in larval bivalves are poorly understood. Here, we use a calcification substrate-limited approach (low dissolved inorganic carbon, C T) and mRNA sequencing to identify proteins involved in bicarbonate acquisition during shell formation. As a secondary approach, we examined expression of ion transport and shell matrix proteins (SMPs) over the course of larval development and shell formation. We reared four families of Mytilus edulis under ambient (ca. 1865 µmol/kg) and low C T (ca. 941 µmol/kg) conditions and compared expression patterns at six developmental time points. Larvae reared under low C T exhibited a developmental delay, and a small subset of contigs was differentially regulated between ambient and low C T conditions. Of particular note was the identification of one contig encoding an anion transporter (SLC26) which was strongly upregulated (2.3-2.9 fold) under low C T conditions. By analyzing gene expression profiles over the course of larval development, we are able to isolate sequences encoding ion transport and SMPs to enhance our understanding of cellular pathways underlying larval calcification processes. In particular, we observe the differential expression of contigs encoding SLC4 family members (sodium bicarbonate cotransporters, anion exchangers), calcium-transporting ATPases, sodium/calcium exchangers, and SMPs such as nacrein, tyrosinase, and transcripts related to chitin production. With a range of candidate genes, this work identifies ion transport pathways in bivalve larvae and by applying comparative genomics to investigate temporal expression patterns, provides a foundation for further studies to functionally characterize the proteins involved in larval calcification.
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Affiliation(s)
- Kirti Ramesh
- GEOMAR Helmholtz Centre for Ocean ResearchKielGermany
- Department of Biological and Environmental Sciences, Sven Lovén Centre for Marine Infrastructure‐KristinebergUniversity of GothenburgFiskebäckskilSweden
| | - Tejaswi Yarra
- British Antarctic SurveyNatural Environment Research CouncilCambridgeUK
- Ashworth Laboratories, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghUK
| | - Melody S. Clark
- British Antarctic SurveyNatural Environment Research CouncilCambridgeUK
| | - Uwe John
- Ecological ChemistryAlfred‐Wegener‐Institut Helmholtz‐Zentrum für Polar‐und MeeresforschungBremerhavenGermany
- Helmholtz‐Institute for Functional Marine BiodiversityOldenburgGermany
| | - Frank Melzner
- GEOMAR Helmholtz Centre for Ocean ResearchKielGermany
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22
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Marcoux AA, Slimani S, Tremblay LE, Frenette-Cotton R, Garneau AP, Isenring P. Regulation of Na +-K +-Cl - cotransporter type 2 by the with no lysine kinase-dependent signaling pathway. Am J Physiol Cell Physiol 2019; 317:C20-C30. [PMID: 30917032 DOI: 10.1152/ajpcell.00041.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Na+-K+-Cl- cotransporter type 2 (NKCC2) is confined to the apical membrane of the thick ascending limb of Henle, where it reabsorbs a substantial fraction of the ultrafiltered NaCl load. It is expressed along this nephron segment as three main splice variants (called NKCC2A, NKCC2B, and NKCC2F) that differ in residue composition along their second transmembrane domain and first intracellular cytosolic connecting segment (CS2). NKCC2 is known to be activated by cell shrinkage and intracellular [Cl-] reduction. Although the with no lysine (WNK) kinases could play a role in this response, the mechanisms involved are ill defined, and the possibility of variant-specific responses has not been tested thus far. In this study, we have used the Xenopus laevis oocyte expression system to gain further insight in these regards. We have found for the first time that cell shrinkage could stimulate NKCC2A- and NKCC2B-mediated ion transport by increasing carrier abundance at the cell surface and that this response was achieved (at least in part) by the enzymatic function of a WNK kinase. Interestingly, we have also found that the activity and cell surface abundance of NKCC2F were less affected by cell shrinkage compared with the other variants and that ion transport by certain variants could be stimulated through WNK kinase expression in the absence of carrier redistribution. Taken together, these results suggest that the WNK kinase-dependent pathway can affect both the trafficking as well as intrinsic activity of NKCC2 and that CS2 plays an important role in carrier regulation.
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Affiliation(s)
- Andrée-Anne Marcoux
- Nephrology Research Group, L'Hôtel-Dieu de Québec Research Center, Department of Medicine, Faculty of Medicine, Laval University , Quebec City, Quebec , Canada
| | - Samira Slimani
- Nephrology Research Group, L'Hôtel-Dieu de Québec Research Center, Department of Medicine, Faculty of Medicine, Laval University , Quebec City, Quebec , Canada
| | - Laurence E Tremblay
- Nephrology Research Group, L'Hôtel-Dieu de Québec Research Center, Department of Medicine, Faculty of Medicine, Laval University , Quebec City, Quebec , Canada
| | - Rachelle Frenette-Cotton
- Nephrology Research Group, L'Hôtel-Dieu de Québec Research Center, Department of Medicine, Faculty of Medicine, Laval University , Quebec City, Quebec , Canada
| | - Alexandre P Garneau
- Nephrology Research Group, L'Hôtel-Dieu de Québec Research Center, Department of Medicine, Faculty of Medicine, Laval University , Quebec City, Quebec , Canada.,Cardiometabolic Research Group, Department of Kinesiology, Faculty of Medicine, University of Montreal , Montreal, Quebec , Canada
| | - Paul Isenring
- Nephrology Research Group, L'Hôtel-Dieu de Québec Research Center, Department of Medicine, Faculty of Medicine, Laval University , Quebec City, Quebec , Canada
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23
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Seidler U, Nikolovska K. Slc26 Family of Anion Transporters in the Gastrointestinal Tract: Expression, Function, Regulation, and Role in Disease. Compr Physiol 2019; 9:839-872. [DOI: 10.1002/cphy.c180027] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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24
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Liu X, Li T, Tuo B. Physiological and Pathophysiological Relevance of the Anion Transporter Slc26a9 in Multiple Organs. Front Physiol 2018; 9:1197. [PMID: 30233393 PMCID: PMC6127633 DOI: 10.3389/fphys.2018.01197] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 08/08/2018] [Indexed: 02/05/2023] Open
Abstract
Transepithelial Cl- and HCO3- transport is crucial for the function of all epithelia, and HCO3- is a biological buffer that maintains acid-base homeostasis. In most epithelia, a series of Cl-/HCO3- exchangers and Cl- channels that mediate Cl- absorption and HCO3- secretion have been detected in the luminal and basolateral membranes. Slc26a9 belongs to the solute carrier 26 (Slc26) family of anion transporters expressed in the epithelia of multiple organs. This review summarizes the expression pattern and functional diversity of Slc26a9 in different systems based on all investigations performed thus far. Furthermore, the physical and functional interactions between Slc26a9 and cystic fibrosis transmembrane conductance regulator (CFTR) are discussed due to their overlapping expression pattern in multiple organs. Finally, we focus on the relationship between slc26a9 mutations and disease onset. An understanding of the physiological and pathophysiological relevance of Slc26a9 in multiple organs offers new possibilities for disease therapy.
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Affiliation(s)
- Xuemei Liu
- Department of Gastroenterology, Affiliated Hospital, Zunyi Medical University, Zunyi, China.,Digestive Disease Institute of Guizhou Province, Zunyi, China
| | - Taolang Li
- Department of Thyroid and Breast Surgery, Affiliated Hospital, Zunyi Medical University, Zunyi, China
| | - Biguang Tuo
- Department of Gastroenterology, Affiliated Hospital, Zunyi Medical University, Zunyi, China.,Digestive Disease Institute of Guizhou Province, Zunyi, China
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25
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Rahmati N, Hoebeek FE, Peter S, De Zeeuw CI. Chloride Homeostasis in Neurons With Special Emphasis on the Olivocerebellar System: Differential Roles for Transporters and Channels. Front Cell Neurosci 2018; 12:101. [PMID: 29765304 PMCID: PMC5938380 DOI: 10.3389/fncel.2018.00101] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 03/28/2018] [Indexed: 12/14/2022] Open
Abstract
The intraneuronal ionic composition is an important determinant of brain functioning. There is growing evidence that aberrant homeostasis of the intracellular concentration of Cl- ([Cl-]i) evokes, in addition to that of Na+ and Ca2+, robust impairments of neuronal excitability and neurotransmission and thereby neurological conditions. More specifically, understanding the mechanisms underlying regulation of [Cl-]i is crucial for deciphering the variability in GABAergic and glycinergic signaling of neurons, in both health and disease. The homeostatic level of [Cl-]i is determined by various regulatory mechanisms, including those mediated by plasma membrane Cl- channels and transporters. This review focuses on the latest advances in identification, regulation and characterization of Cl- channels and transporters that modulate neuronal excitability and cell volume. By putting special emphasis on neurons of the olivocerebellar system, we establish that Cl- channels and transporters play an indispensable role in determining their [Cl-]i and thereby their function in sensorimotor coordination.
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Affiliation(s)
- Negah Rahmati
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, Netherlands
| | - Freek E. Hoebeek
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, Netherlands
- NIDOD Institute, Wilhelmina Children's Hospital, University Medical Center Utrecht and Brain Center Rudolf Magnus, Utrecht, Netherlands
| | - Saša Peter
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, Netherlands
| | - Chris I. De Zeeuw
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, Netherlands
- Netherlands Institute for Neuroscience, Royal Dutch Academy for Arts and Sciences, Amsterdam, Netherlands
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26
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Wang Y, Li Y, Liu X, Pu W, Wang X, Wang J, Xiong M, Yao Shugart Y, Jin L. Bagging Nearest-Neighbor Prediction independence Test: an efficient method for nonlinear dependence of two continuous variables. Sci Rep 2017; 7:12736. [PMID: 28986523 PMCID: PMC5630623 DOI: 10.1038/s41598-017-12783-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 09/15/2017] [Indexed: 12/03/2022] Open
Abstract
Testing dependence/correlation of two variables is one of the fundamental tasks in statistics. In this work, we proposed an efficient method for nonlinear dependence of two continuous variables (X and Y). We addressed this research question by using BNNPT (Bagging Nearest-Neighbor Prediction independence Test, software available at https://sourceforge.net/projects/bnnpt/). In the BNNPT framework, we first used the value of X to construct a bagging neighborhood structure. We then obtained the out of bag estimator of Y based on the bagging neighborhood structure. The square error was calculated to measure how well Y is predicted by X. Finally, a permutation test was applied to determine the significance of the observed square error. To evaluate the strength of BNNPT compared to seven other methods, we performed extensive simulations to explore the relationship between various methods and compared the false positive rates and statistical power using both simulated and real datasets (Rugao longevity cohort mitochondrial DNA haplogroups and kidney cancer RNA-seq datasets). We concluded that BNNPT is an efficient computational approach to test nonlinear correlation in real world applications.
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Affiliation(s)
- Yi Wang
- Ministry of Education Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China
| | - Yi Li
- Ministry of Education Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China
| | - Xiaoyu Liu
- Ministry of Education Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China
| | - Weilin Pu
- Ministry of Education Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China
| | - Xiaofeng Wang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China
| | - Jiucun Wang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China
| | - Momiao Xiong
- Ministry of Education Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China.,Human Genetics Center, School of Public Health, University of Texas Houston Health Sciences Center, Houston, Texas, USA
| | - Yin Yao Shugart
- Ministry of Education Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China. .,Unit on Statistical Genomics, Division of Intramural Division Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
| | - Li Jin
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China.
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27
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Kersten S, Arjona FJ. Ion transport in the zebrafish kidney from a human disease angle: possibilities, considerations, and future perspectives. Am J Physiol Renal Physiol 2017; 312:F172-F189. [DOI: 10.1152/ajprenal.00425.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 11/11/2016] [Accepted: 11/14/2016] [Indexed: 12/31/2022] Open
Abstract
Unique experimental advantages, such as its embryonic/larval transparency, high-throughput nature, and ease of genetic modification, underpin the rapid emergence of the zebrafish ( Danio rerio) as a preeminent model in biomedical research. Particularly in the field of nephrology, the zebrafish provides a promising model for studying the physiological implications of human solute transport processes along consecutive nephron segments. However, although the zebrafish might be considered a valuable model for numerous renal ion transport diseases and functional studies of many channels and transporters, not all human renal electrolyte transport mechanisms and human diseases can be modeled in the zebrafish. With this review, we explore the ontogeny of zebrafish renal ion transport, its nephron structure and function, and thereby demonstrate the clinical translational value of this model. By critical assessment of genomic and amino acid conservation of human proteins involved in renal ion handling (channels, transporters, and claudins), kidney and nephron segment conservation, and renal electrolyte transport physiology in the zebrafish, we provide researchers and nephrologists with an indication of the possibilities and considerations of the zebrafish as a model for human renal ion transport. Combined with advanced techniques envisioned for the future, implementation of the zebrafish might expand beyond unraveling pathophysiological mechanisms that underlie distinct genetic or environmentally, i.e., pharmacological and lifestyle, induced renal transport deficits. Specifically, the ease of drug administration and the exploitation of improved genetic approaches might argue for the adoption of the zebrafish as a model for preclinical personalized medicine for distinct renal diseases and renal electrolyte transport proteins.
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Affiliation(s)
- Simone Kersten
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; and
- Nephrology Division, Department of Medicine, Massachusetts General Hospital, Charlestown, Massachusetts
| | - Francisco J. Arjona
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; and
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28
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Mittal R, Aranke M, Debs LH, Nguyen D, Patel AP, Grati M, Mittal J, Yan D, Chapagain P, Eshraghi AA, Liu XZ. Indispensable Role of Ion Channels and Transporters in the Auditory System. J Cell Physiol 2016; 232:743-758. [DOI: 10.1002/jcp.25631] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 09/30/2016] [Indexed: 12/18/2022]
Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Mayank Aranke
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Luca H. Debs
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Desiree Nguyen
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Amit P. Patel
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - M'hamed Grati
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Jeenu Mittal
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Denise Yan
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Prem Chapagain
- Department of Physics; Florida International University; Miami Florida
- Biomolecular Science Institute; Florida International University; Miami Florida
| | - Adrien A. Eshraghi
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
| | - Xue Zhong Liu
- Department of Otolaryngology; University of Miami Miller School of Medicine; Miami Florida
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29
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Hosoya M, Fujioka M, Kobayashi R, Okano H, Ogawa K. Overlapping expression of anion exchangers in the cochlea of a non-human primate suggests functional compensation. Neurosci Res 2016; 110:1-10. [PMID: 27091614 DOI: 10.1016/j.neures.2016.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/27/2016] [Accepted: 04/05/2016] [Indexed: 11/19/2022]
Abstract
Ion homeostasis in the inner ear is essential for proper hearing. Anion exchangers are one of the transporters responsible for the maintenance of homeostasis, but their expression profile in the primate cochlea has not been fully characterized. However, species-specific overlapping expression patterns and functional compensation in other organs, such as the kidney, pancreas and small intestine, have been reported. Here, we determined the expression patterns of the anion exchangers SLC26A4, SLC26A5, SLC26A6, SLC26A7, SLC26A11, SLC4A2 and SLC4A3 in the cochlea of a non-human primate, the common marmoset (Callithrix jacchus). Although the pattern of expression of SLC26A4 and SLC26A5 was similar to that in rodents, SLC26A7, SLC4A2, SLC4A3 exhibited different distributions. Notably, five transporters, SLC26A4, SLC26A6, SLC26A11 SLC4A2 and SLC4A3, were expressed in the cells of the outer sulcus. Our results reveal a species-specific distribution pattern of anion exchangers in the cochlea, particularly in the outer sulcus cells, suggesting functional compensation among these exchangers. This "primate-specific" pattern may be related to the human-specific hearing loss phenotypes of channelopathy disorders, including the SLC26A4-related diseases Pendred syndrome/DFNB4.
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Affiliation(s)
- Makoto Hosoya
- Keio University School of Medicine, Department of Otorhinolaryngology, Head and Neck Surgery, 35 Shinanomachi, Shinjuku-ku 160-8582, Japan
| | - Masato Fujioka
- Keio University School of Medicine, Department of Otorhinolaryngology, Head and Neck Surgery, 35 Shinanomachi, Shinjuku-ku 160-8582, Japan.
| | - Reona Kobayashi
- Keio University School of Medicine, Department of Physiology, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Hideyuki Okano
- Keio University School of Medicine, Department of Physiology, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Kaoru Ogawa
- Keio University School of Medicine, Department of Otorhinolaryngology, Head and Neck Surgery, 35 Shinanomachi, Shinjuku-ku 160-8582, Japan
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30
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Chung VY, Konietzny R, Charles P, Kessler B, Fischer R, Turney BW. Proteomic changes in response to crystal formation in Drosophila Malpighian tubules. Fly (Austin) 2016; 10:91-100. [PMID: 27064297 DOI: 10.1080/19336934.2016.1171947] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Kidney stone disease is a major health burden with a complex and poorly understood pathophysiology. Drosophila Malpighian tubules have been shown to resemble human renal tubules in their physiological function. Herein, we have used Drosophila as a model to study the proteomic response to crystal formation induced by dietary manipulation in Malpighian tubules. Wild-type male flies were reared in parallel groups on standard medium supplemented with lithogenic agents: control, Sodium Oxalate (NaOx) and Ethylene Glycol (EG). Malpighian tubules were dissected after 2 weeks to visualize crystals with polarized light microscopy. The parallel group was dissected for protein extraction. A new method of Gel Assisted Sample Preparation (GASP) was used for protein extraction. Differentially abundant proteins (p<0.05) were identified by label-free quantitative proteomic analysis in flies fed with NaOx and EG diet compared with control. Their molecular functions were further screened for transmembrane ion transporter, calcium or zinc ion binder. Among these, 11 candidate proteins were shortlisted in NaOx diet and 16 proteins in EG diet. We concluded that GASP is a proteomic sample preparation method that can be applied to individual Drosophila Malpighian tubules. Our results may further increase the understanding of the pathophysiology of human kidney stone disease.
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Affiliation(s)
- Vera Y Chung
- a Oxford Stone Group, Department of Urology, Nuffield Department of Surgical Sciences, University of Oxford , UK
| | - Rebecca Konietzny
- b Target Discovery Institute, Nuffield Department of Medicine, University of Oxford , UK
| | - Philip Charles
- b Target Discovery Institute, Nuffield Department of Medicine, University of Oxford , UK
| | - Benedikt Kessler
- b Target Discovery Institute, Nuffield Department of Medicine, University of Oxford , UK
| | - Roman Fischer
- b Target Discovery Institute, Nuffield Department of Medicine, University of Oxford , UK
| | - Benjamin W Turney
- a Oxford Stone Group, Department of Urology, Nuffield Department of Surgical Sciences, University of Oxford , UK
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31
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The Role of Epithelial Sodium Channel ENaC and the Apical Cl-/HCO3- Exchanger Pendrin in Compensatory Salt Reabsorption in the Setting of Na-Cl Cotransporter (NCC) Inactivation. PLoS One 2016; 11:e0150918. [PMID: 26963391 PMCID: PMC4786216 DOI: 10.1371/journal.pone.0150918] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 02/18/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The absence of NCC does not cause significant salt wasting in NCC deficient mice under basal conditions. We hypothesized that ENaC and pendrin play important roles in compensatory salt absorption in the setting of NCC inactivation, and their inhibition and/or downregulation can cause significant salt wasting in NCC KO mice. METHODS WT and NCC KO mice were treated with a daily injection of either amiloride, an inhibitor of ENaC, or acetazolamide (ACTZ), a blocker of salt and bicarbonate reabsorption in the proximal tubule and an inhibitor of carbonic anhydrases in proximal tubule and intercalated cells, or a combination of acetazolamide plus amiloride for defined durations. Animals were subjected to daily balance studies. At the end of treatment, kidneys were harvested and examined. Blood samples were collected for electrolytes and acid base analysis. RESULTS Amiloride injection significantly increased the urine output (UO) in NCC KO mice (from 1.3 ml/day before to 2.5 ml/day after amiloride, p<0.03, n = 4) but caused only a slight change in UO in WT mice (p>0.05). The increase in UO in NCC KO mice was associated with a significant increase in sodium excretion (from 0.25 mmol/24 hrs at baseline to 0.35 mmol/24 hrs after amiloride injection, p<0.05, n = 4). Daily treatment with ACTZ for 6 days resulted in >80% reduction of kidney pendrin expression in both WT and NCC KO mice. However, ACTZ treatment noticeably increased urine output and salt excretion only in NCC KO mice (with urine output increasing from a baseline of 1.1 ml/day to 2.3 ml/day and sodium excretion increasing from 0.22 mmole/day before to 0.31 mmole/day after ACTZ) in NCC KO mice; both parameters were significantly higher than in WT mice. Western blot analysis demonstrated significant enhancement in ENaC expression in medulla and cortex of NCC KO and WT mice in response to ACTZ injection for 6 days, and treatment with amiloride in ACTZ-pretreated mice caused a robust increase in salt excretion in both NCC KO and WT mice. Pendrin KO mice did not display a significant increase in urine output or salt excretion after treatment with amiloride or ACTZ. CONCLUSION 1. ENaC plays an important role in salt reabsorption in NCC KO mice. 2. NCC contributes to compensatory salt reabsorption in the setting of carbonic anhydrase inhibition, which is associated with increased delivery of salt from the proximal tubule and the down regulation of pendrin. 3. ENaC is upregulated by ACTZ treatment and its inhibition by amiloride causes significant diuresis in NCC KO and WT mice. Despite being considered mild agents individually, we propose that the combination of acetazolamide and amiloride in the setting of NCC inhibition (i.e., hydrochlorothiazide) will be a powerful diuretic regimen.
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32
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Abstract
Acid-base homeostasis and pH regulation are critical for both normal physiology and cell metabolism and function. The importance of this regulation is evidenced by a variety of physiologic derangements that occur when plasma pH is either high or low. The kidneys have the predominant role in regulating the systemic bicarbonate concentration and hence, the metabolic component of acid-base balance. This function of the kidneys has two components: reabsorption of virtually all of the filtered HCO3(-) and production of new bicarbonate to replace that consumed by normal or pathologic acids. This production or generation of new HCO3(-) is done by net acid excretion. Under normal conditions, approximately one-third to one-half of net acid excretion by the kidneys is in the form of titratable acid. The other one-half to two-thirds is the excretion of ammonium. The capacity to excrete ammonium under conditions of acid loads is quantitatively much greater than the capacity to increase titratable acid. Multiple, often redundant pathways and processes exist to regulate these renal functions. Derangements in acid-base homeostasis, however, are common in clinical medicine and can often be related to the systems involved in acid-base transport in the kidneys.
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Affiliation(s)
- L Lee Hamm
- Department of Medicine, Section of Nephrology, Tulane Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, Louisiana; and Medicine Service, Southeast Louisiana Veterans Health Care System, New Orleans, Louisiana
| | - Nazih Nakhoul
- Department of Medicine, Section of Nephrology, Tulane Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, Louisiana; and Medicine Service, Southeast Louisiana Veterans Health Care System, New Orleans, Louisiana
| | - Kathleen S Hering-Smith
- Department of Medicine, Section of Nephrology, Tulane Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, Louisiana; and Medicine Service, Southeast Louisiana Veterans Health Care System, New Orleans, Louisiana
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33
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Pant SD, Karlskov-Mortensen P, Jacobsen MJ, Cirera S, Kogelman LJA, Bruun CS, Mark T, Jørgensen CB, Grarup N, Appel EVR, Galjatovic EAA, Hansen T, Pedersen O, Guerin M, Huby T, Lesnik P, Meuwissen THE, Kadarmideen HN, Fredholm M. Comparative Analyses of QTLs Influencing Obesity and Metabolic Phenotypes in Pigs and Humans. PLoS One 2015; 10:e0137356. [PMID: 26348622 PMCID: PMC4562524 DOI: 10.1371/journal.pone.0137356] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 08/14/2015] [Indexed: 12/31/2022] Open
Abstract
The pig is a well-known animal model used to investigate genetic and mechanistic aspects of human disease biology. They are particularly useful in the context of obesity and metabolic diseases because other widely used models (e.g. mice) do not completely recapitulate key pathophysiological features associated with these diseases in humans. Therefore, we established a F2 pig resource population (n = 564) designed to elucidate the genetics underlying obesity and metabolic phenotypes. Segregation of obesity traits was ensured by using breeds highly divergent with respect to obesity traits in the parental generation. Several obesity and metabolic phenotypes were recorded (n = 35) from birth to slaughter (242 ± 48 days), including body composition determined at about two months of age (63 ± 10 days) via dual-energy x-ray absorptiometry (DXA) scanning. All pigs were genotyped using Illumina Porcine 60k SNP Beadchip and a combined linkage disequilibrium-linkage analysis was used to identify genome-wide significant associations for collected phenotypes. We identified 229 QTLs which associated with adiposity- and metabolic phenotypes at genome-wide significant levels. Subsequently comparative analyses were performed to identify the extent of overlap between previously identified QTLs in both humans and pigs. The combined analysis of a large number of obesity phenotypes has provided insight in the genetic architecture of the molecular mechanisms underlying these traits indicating that QTLs underlying similar phenotypes are clustered in the genome. Our analyses have further confirmed that genetic heterogeneity is an inherent characteristic of obesity traits most likely caused by segregation or fixation of different variants of the individual components belonging to cellular pathways in different populations. Several important genes previously associated to obesity in human studies, along with novel genes were identified. Altogether, this study provides novel insight that may further the current understanding of the molecular mechanisms underlying human obesity.
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Affiliation(s)
- Sameer D. Pant
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Karlskov-Mortensen
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette J. Jacobsen
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Susanna Cirera
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lisette J. A. Kogelman
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Camilla S. Bruun
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Mark
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Claus B. Jørgensen
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Niels Grarup
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emil V. R. Appel
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ehm A. A. Galjatovic
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Torben Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Oluf Pedersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maryse Guerin
- INSERM UMR_S 1166, Integrative Biology of Atherosclerosis Team, F-75013, Paris, France
- Sorbonne Universités UPMC Univ Paris 06 UMR_S 1166, Integrative Biology of Atherosclerosis Team, F-75013, Paris, France
- Institute of Cardiometabolism and Nutrition (ICAN), Pitié-Salpêtrière Hospital, 75013, Paris, France
| | - Thierry Huby
- INSERM UMR_S 1166, Integrative Biology of Atherosclerosis Team, F-75013, Paris, France
- Sorbonne Universités UPMC Univ Paris 06 UMR_S 1166, Integrative Biology of Atherosclerosis Team, F-75013, Paris, France
- Institute of Cardiometabolism and Nutrition (ICAN), Pitié-Salpêtrière Hospital, 75013, Paris, France
| | - Philipppe Lesnik
- INSERM UMR_S 1166, Integrative Biology of Atherosclerosis Team, F-75013, Paris, France
- Sorbonne Universités UPMC Univ Paris 06 UMR_S 1166, Integrative Biology of Atherosclerosis Team, F-75013, Paris, France
- Institute of Cardiometabolism and Nutrition (ICAN), Pitié-Salpêtrière Hospital, 75013, Paris, France
| | - Theo H. E. Meuwissen
- Institute of Animal and Agricultural Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Haja N. Kadarmideen
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail: (MF); (HNK)
| | - Merete Fredholm
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail: (MF); (HNK)
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Schatzberg D, Lawton M, Hadyniak SE, Ross EJ, Carney T, Beane WS, Levin M, Bradham CA. H(+)/K(+) ATPase activity is required for biomineralization in sea urchin embryos. Dev Biol 2015; 406:259-70. [PMID: 26282894 DOI: 10.1016/j.ydbio.2015.08.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/26/2015] [Accepted: 08/13/2015] [Indexed: 12/31/2022]
Abstract
The bioelectrical signatures associated with regeneration, wound healing, development, and cancer are changes in the polarization state of the cell that persist over long durations, and are mediated by ion channel activity. To identify physiologically relevant bioelectrical changes that occur during normal development of the sea urchin Lytechinus variegatus, we tested a range of ion channel inhibitors, and thereby identified SCH28080, a chemical inhibitor of the H(+)/K(+) ATPase (HKA), as an inhibitor of skeletogenesis. In sea urchin embryos, the primary mesodermal lineage, the PMCs, produce biomineral in response to signals from the ectoderm. However, in SCH28080-treated embryos, aside from randomization of the left-right axis, the ectoderm is normally specified and differentiated, indicating that the block to skeletogenesis observed in SCH28080-treated embryos is PMC-specific. HKA inhibition did not interfere with PMC specification, and was sufficient to block continuing biomineralization when embryos were treated with SCH28080 after the initiation of skeletogenesis, indicating that HKA activity is continuously required during biomineralization. Ion concentrations and voltage potential were abnormal in the PMCs in SCH28080-treated embryos, suggesting that these bioelectrical abnormalities prevent biomineralization. Our results indicate that this effect is due to the inhibition of amorphous calcium carbonate precipitation within PMC vesicles.
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Affiliation(s)
| | - Matthew Lawton
- Department of Biology, Boston University, Boston, MA 02215, USA
| | | | - Erik J Ross
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Tamara Carney
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Wendy S Beane
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008, USA
| | - Michael Levin
- Department of Biology, Tufts University, Medford, MA 02155, USA
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Evan AP, Coe FL, Connors BA, Handa RK, Lingeman JE, Worcester EM. Mechanism by which shock wave lithotripsy can promote formation of human calcium phosphate stones. Am J Physiol Renal Physiol 2015; 308:F938-49. [PMID: 25656372 PMCID: PMC4398833 DOI: 10.1152/ajprenal.00655.2014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 01/29/2015] [Indexed: 11/22/2022] Open
Abstract
Human stone calcium phosphate (CaP) content correlates with higher urine CaP supersaturation (SS) and urine pH as well as with the number of shock wave lithotripsy (SWL) treatments. SWL does damage medullary collecting ducts and vasa recta, sites for urine pH regulation. We tested the hypothesis that SWL raises urine pH and therefore Cap SS, resulting in CaP nucleation and tubular plugging. The left kidney (T) of nine farm pigs was treated with SWL, and metabolic studies were performed using bilateral ureteral catheters for up to 70 days post-SWL. Some animals were given an NH4Cl load to sort out effects on urine pH of CD injury vs. increased HCO3 (-) delivery. Histopathological studies were performed at the end of the functional studies. The mean pH of the T kidneys exceeded that of the control (C) kidneys by 0.18 units in 14 experiments on 9 pigs. Increased HCO3 (-) delivery to CD is at least partly responsible for the pH difference because NH4Cl acidosis abolished it. The T kidneys excreted more Na, K, HCO3 (-), water, Ca, Mg, and Cl than C kidneys. A single nephron site that could produce losses of all of these is the thick ascending limb. Extensive injury was noted in medullary thick ascending limbs and collecting ducts. Linear bands showing nephron loss and fibrosis were found in the cortex and extended into the medulla. Thus SWL produces tubule cell injury easily observed histopathologically that leads to functional disturbances across a wide range of electrolyte metabolism including higher than control urine pH.
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Affiliation(s)
- Andrew P Evan
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana; International Kidney Stone Institute, Methodist Hospital, Indianapolis, Indiana; and
| | - Fredric L Coe
- Nephrology Section, University of Chicago, Chicago, Illinois
| | - Bret A Connors
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Rajash K Handa
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - James E Lingeman
- International Kidney Stone Institute, Methodist Hospital, Indianapolis, Indiana; and
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Soleimani M. The multiple roles of pendrin in the kidney. Nephrol Dial Transplant 2014; 30:1257-66. [PMID: 25281699 DOI: 10.1093/ndt/gfu307] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 08/25/2014] [Indexed: 12/30/2022] Open
Abstract
The [Formula: see text] exchanger pendrin (SLC26A4, PDS) is located on the apical membrane of B-intercalated cells in the kidney cortical collecting duct and the connecting tubules and mediates the secretion of bicarbonate and the reabsorption of chloride. Given its dual function of bicarbonate secretion and chloride reabsorption in the distal tubules, it was thought that pendrin plays important roles in systemic acid-base balance and electrolyte and vascular volume homeostasis under basal conditions. Mice with the genetic deletion of pendrin or humans with inactivating mutations in PDS gene, however, do not display excessive salt and fluid wasting or altered blood pressure under baseline conditions. Very recent reports have unmasked the basis of incongruity between the mild phenotype in mutant mice and the role of pendrin as an important player in salt reabsorption in the distal tubule. These studies demonstrate that pendrin and the Na-Cl cotransporter (NCC; SLC12A3) cross compensate for the loss of each other, therefore masking the role that each transporter plays in salt reabsorption under baseline conditions. In addition, pendrin regulates calcium reabsorption in the distal tubules. Furthermore, combined deletion of pendrin and NCC not only causes severe volume depletion but also results in profound calcium wasting and luminal calcification in medullary collecting ducts. Based on studies in pathophysiological states and the examination of genetically engineered mouse models, the evolving picture points to important roles for pendrin (SLC26A4) in kidney physiology and in disease states. This review summarizes recent advances in the characterization of pendrin and the multiple roles it plays in the kidney, with emphasis on its essential roles in several diverse physiological processes, including chloride homeostasis, vascular volume and blood pressure regulation, calcium excretion and kidney stone formation.
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Affiliation(s)
- Manoocher Soleimani
- Center on Genetics of Transport and Epithelial Biology, University of Cincinnati, Cincinnati, OH, USA Research Services, Veterans Affairs Medical Center, Cincinnati, OH, USA Department of Medicine, University of Cincinnati, Cincinnati, OH, USA
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Wang HS, Chen Y, Vairamani K, Shull GE. Critical role of bicarbonate and bicarbonate transporters in cardiac function. World J Biol Chem 2014; 5:334-345. [PMID: 25225601 PMCID: PMC4160527 DOI: 10.4331/wjbc.v5.i3.334] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/06/2014] [Accepted: 05/19/2014] [Indexed: 02/05/2023] Open
Abstract
Bicarbonate is one of the major anions in mammalian tissues and extracellular fluids. Along with accompanying H+, HCO3- is generated from CO2 and H2O, either spontaneously or via the catalytic activity of carbonic anhydrase. It serves as a component of the major buffer system, thereby playing a critical role in pH homeostasis. Bicarbonate can also be utilized by a variety of ion transporters, often working in coupled systems, to transport other ions and organic substrates across cell membranes. The functions of HCO3- and HCO3--transporters in epithelial tissues have been studied extensively, but their functions in heart are less well understood. Here we review studies of the identities and physiological functions of Cl-/HCO3- exchangers and Na+/HCO3- cotransporters of the SLC4A and SLC26A families in heart. We also present RNA Seq analysis of their cardiac mRNA expression levels. These studies indicate that slc4a3 (AE3) is the major Cl-/HCO3- exchanger and plays a protective role in heart failure, and that Slc4a4 (NBCe1) is the major Na+/HCO3- cotransporter and affects action potential duration. In addition, previous studies show that HCO3- has a positive inotropic effect in the perfused heart that is largely independent of effects on intracellular Ca2+. The importance of HCO3- in the regulation of contractility is supported by experiments showing that isolated cardiomyocytes exhibit sharply enhanced contractility, with no change in Ca2+ transients, when switched from Hepes-buffered to HCO3-- buffered solutions. These studies demonstrate that HCO3- and HCO3--handling proteins play important roles in the regulation of cardiac function.
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Jennings ML. Transport of H2S and HS(-) across the human red blood cell membrane: rapid H2S diffusion and AE1-mediated Cl(-)/HS(-) exchange. Am J Physiol Cell Physiol 2013; 305:C941-50. [PMID: 23864610 PMCID: PMC4042536 DOI: 10.1152/ajpcell.00178.2013] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The rates of H2S and HS(-) transport across the human erythrocyte membrane were estimated by measuring rates of dissipation of pH gradients in media containing 250 μM H2S/HS(-). Net acid efflux is caused by H2S/HS(-) acting analogously to CO2/HCO3(-) in the Jacobs-Stewart cycle. The steps are as follows: 1) H2S efflux through the lipid bilayer and/or a gas channel, 2) extracellular H2S deprotonation, 3) HS(-) influx in exchange for Cl(-), catalyzed by the anion exchange protein AE1, and 4) intracellular HS(-) protonation. Net acid transport by the Cl(-)/HS(-)/H2S cycle is more efficient than by the Cl(-)/HCO3(-)/CO2 cycle because of the rapid H2S-HS(-) interconversion in cells and medium. The rates of acid transport were analyzed by solving the mass flow equations for the cycle to produce estimates of the HS(-) and H2S transport rates. The data indicate that HS(-) is a very good substrate for AE1; the Cl(-)/HS(-) exchange rate is about one-third as rapid as Cl(-)/HCO3(-) exchange. The H2S permeability coefficient must also be high (>10(-2) cm/s, half time <0.003 s) to account for the pH equilibration data. The results imply that H2S and HS(-) enter erythrocytes very rapidly in the microcirculation of H2S-producing tissues, thereby acting as a sink for H2S and lowering the local extracellular concentration, and the fact that HS(-) is a substrate for a Cl(-)/HCO3(-) exchanger indicates that some effects of exogenous H2S/HS(-) may not result from a regulatory role of H2S but, rather, from net acid flux by H2S and HS(-) transport in a Jacobs-Stewart cycle.
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Affiliation(s)
- Michael L Jennings
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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