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Li Q, Wang J, Zang R, Yu L, Yang Z, Sun S. Congenital chloride diarrhoea in a Chinese infant with a compound heterozygous SLC26A3 mutation. BMC Pediatr 2024; 24:305. [PMID: 38704545 PMCID: PMC11069184 DOI: 10.1186/s12887-024-04788-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 04/24/2024] [Indexed: 05/06/2024] Open
Abstract
INTRODUCTION Congenital chloride diarrhoea (CCD) is an autosomal recessive condition that causes secretory diarrhoea and potentially deadly electrolyte imbalances in infants because of solute carrier family 26 member 3 (SLC26A3) gene mutations. CASE PRESENTATION A 7-month-old Chinese infant with a history of maternal polyhydramnios presented with frequent watery diarrhoea, severe dehydration, hypokalaemia, hyponatraemia, failure to thrive, metabolic alkalosis, hyperreninaemia, and hyperaldosteronaemia. Genetic testing revealed a compound heterozygous SLC26A3 gene mutation in this patient (c.269_270dup and c.2006 C > A). Therapy was administered in the form of oral sodium and potassium chloride supplements, which decreased stool frequency. CONCLUSIONS CCD should be considered when an infant presents with prolonged diarrhoea during infancy, particularly in the context of maternal polyhydramnios and dilated foetal bowel loops.
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Affiliation(s)
- Qian Li
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250021, P.R. China
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, P.R. China
| | - Jing Wang
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250021, P.R. China
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, P.R. China
| | - Ruixian Zang
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, P.R. China
| | - Lichun Yu
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250021, P.R. China
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, P.R. China
| | - Zhenle Yang
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250021, P.R. China
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, P.R. China
| | - Shuzhen Sun
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250021, P.R. China.
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, P.R. China.
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Peña-Münzenmayer G, George AT, Llontop N, Mazola Y, Apablaza N, Spichiger C, Brauchi S, Sarmiento J, Zúñiga L, González W, Catalán MA. K +-Driven Cl -/HCO 3- Exchange Mediated by Slc4a8 and Slc4a10. Int J Mol Sci 2024; 25:4575. [PMID: 38674160 PMCID: PMC11050268 DOI: 10.3390/ijms25084575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
Slc4a genes encode various types of transporters, including Na+-HCO3- cotransporters, Cl-/HCO3- exchangers, or Na+-driven Cl-/HCO3- exchangers. Previous research has revealed that Slc4a9 (Ae4) functions as a Cl-/HCO3- exchanger, which can be driven by either Na+ or K+, prompting investigation into whether other Slc4a members facilitate cation-dependent anion transport. In the present study, we show that either Na+ or K+ drive Cl-/HCO3- exchanger activity in cells overexpressing Slc4a8 or Slc4a10. Further characterization of cation-driven Cl-/HCO3- exchange demonstrated that Slc4a8 and Slc4a10 also mediate Cl- and HCO3--dependent K+ transport. Full-atom molecular dynamics simulation on the recently solved structure of Slc4a8 supports the coordination of K+ at the Na+ binding site in S1. Sequence analysis shows that the critical residues coordinating monovalent cations are conserved among mouse Slc4a8 and Slc4a10 proteins. Together, our results suggest that Slc4a8 and Slc4a10 might transport K+ in the same direction as HCO3- ions in a similar fashion to that described for Na+ transport in the rat Slc4a8 structure.
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Affiliation(s)
- Gaspar Peña-Münzenmayer
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile; (G.P.-M.); (N.A.); (C.S.)
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Valdivia 5090000, Chile
| | - Alvin T. George
- Secretory Mechanisms and Dysfunction Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nuria Llontop
- Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia 5090000, Chile; (N.L.); (J.S.)
| | - Yuliet Mazola
- Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, Talca 3460000, Chile (W.G.)
| | - Natalia Apablaza
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile; (G.P.-M.); (N.A.); (C.S.)
| | - Carlos Spichiger
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile; (G.P.-M.); (N.A.); (C.S.)
| | - Sebastián Brauchi
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Valdivia 5090000, Chile
- Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia 5090000, Chile; (N.L.); (J.S.)
| | - José Sarmiento
- Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia 5090000, Chile; (N.L.); (J.S.)
| | - Leandro Zúñiga
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, Talca 3460000, Chile;
| | - Wendy González
- Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, Talca 3460000, Chile (W.G.)
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Talca 3460000, Chile
| | - Marcelo A. Catalán
- Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia 5090000, Chile; (N.L.); (J.S.)
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3
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Lee D, Hong JH. Chloride/Multiple Anion Exchanger SLC26A Family: Systemic Roles of SLC26A4 in Various Organs. Int J Mol Sci 2024; 25:4190. [PMID: 38673775 PMCID: PMC11050216 DOI: 10.3390/ijms25084190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 03/31/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
Solute carrier family 26 member 4 (SLC26A4) is a member of the SLC26A transporter family and is expressed in various tissues, including the airway epithelium, kidney, thyroid, and tumors. It transports various ions, including bicarbonate, chloride, iodine, and oxalate. As a multiple-ion transporter, SLC26A4 is involved in the maintenance of hearing function, renal function, blood pressure, and hormone and pH regulation. In this review, we have summarized the various functions of SLC26A4 in multiple tissues and organs. Moreover, the relationships between SLC26A4 and other channels, such as cystic fibrosis transmembrane conductance regulator, epithelial sodium channel, and sodium chloride cotransporter, are highlighted. Although the modulation of SLC26A4 is critical for recovery from malfunctions of various organs, development of specific inducers or agonists of SLC26A4 remains challenging. This review contributes to providing a better understanding of the role of SLC26A4 and development of therapeutic approaches for the SLC26A4-associated hearing loss and SLC26A4-related dysfunction of various organs.
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Affiliation(s)
| | - Jeong Hee Hong
- Department of Health Sciences and Technology, GAIHST (Gachon Advanced Institute for Health Sciences and Technology), Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 155 Getbeolro, Yeonsu-gu, Incheon 21999, Republic of Korea;
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4
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Amiri M, Jiang M, Salari A, Xiu R, Alper SL, Seidler UE. Reduced surface pH and upregulated AE2 anion exchange in SLC26A3-deleted polarized intestinal epithelial cells. Am J Physiol Cell Physiol 2024; 326:C829-C842. [PMID: 38223928 DOI: 10.1152/ajpcell.00590.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/21/2023] [Accepted: 01/02/2024] [Indexed: 01/16/2024]
Abstract
Loss of function mutations in the SLC26A3 gene cause chloride-losing diarrhea in mice and humans. Although systemic adaptive changes have been documented in these patients and in the corresponding knockout mice, how colonic enterocytes adapt to loss of this highly expressed and highly regulated luminal membrane anion exchanger remains unclear. To address this question, SLC26A3 was deleted in the self-differentiating Caco2BBe colonic cell line by the CRISPR/Cas9 technique. We selected a clone with loss of SLC26A3 protein expression and morphological features indistinguishable from those of the native cell line. Neither growth curves nor development of transepithelial electrical resistance (TEER) differed between wild-type (WT) and SLC26A3 knockout (KO) cells. Real-time qPCR and Western analysis in SLC26A3-KO cells revealed an increase in AE2 expression without significant change in NHE3 expression or localization. Steady-state pHi and apical and basolateral Cl-/HCO3- exchange activities were assessed fluorometrically in a dual perfusion chamber with independent perfusion of luminal and serosal baths. Apical Cl-/HCO3- exchange rates were strongly reduced in SLC26A3-KO cells, accompanied by a surface pH more acidic than that of WT cells. Steady-state pHi was not significantly different from that of WT cells, but basolateral Cl-/HCO3- exchange rates were higher in SLC26A3-KO than in WT cells. The data show that CRISPR/Cas9-mediated SLC26A3 deletion strongly reduced apical Cl-/HCO3- exchange rate and apical surface pH, but sustained a normal steady-state pHi due to increased expression and function of basolateral AE2. The low apical surface pH resulted in functional inhibition of NHE-mediated fluid absorption despite normal expression of NHE3 polypeptide.NEW & NOTEWORTHY SLC26A3 gene mutations cause chloride-losing diarrhea. To understand how colonic enterocytes adapt, SLC26A3 was deleted in Caco2BBe cells using CRISPR/Cas9. In comparison to the wild-type cells, SLC26A3 knockout cells showed similar growth and transepithelial resistance but substantially reduced apical Cl-/HCO3- exchange rates, and an acidic surface pH. Steady-state intracellular pH was comparable between the WT and KO cells due to increased basolateral AE2 expression and function.
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Affiliation(s)
- Mahdi Amiri
- Department of Gastroenterology, Hannover Medical School, Hannover, Germany
| | - Min Jiang
- Department of Gastroenterology, Hannover Medical School, Hannover, Germany
| | - Azam Salari
- Department of Gastroenterology, Hannover Medical School, Hannover, Germany
| | - Renjie Xiu
- Department of Gastroenterology, Hannover Medical School, Hannover, Germany
| | - Seth L Alper
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States
| | - Ursula E Seidler
- Department of Gastroenterology, Hannover Medical School, Hannover, Germany
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5
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Zhang W, Ding D, Lu Y, Chen H, Jiang P, Zuo P, Wang G, Luo J, Yin Y, Luo J, Yin Y. Structural and functional insights into the lipid regulation of human anion exchanger 2. Nat Commun 2024; 15:759. [PMID: 38272905 PMCID: PMC10810954 DOI: 10.1038/s41467-024-44966-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 01/11/2024] [Indexed: 01/27/2024] Open
Abstract
Anion exchanger 2 (AE2) is an electroneutral Na+-independent Cl-/HCO3- exchanger belongs to the SLC4 transporter family. The widely expressed AE2 participates in a variety of physiological processes, including transepithelial acid-base secretion and osteoclastogenesis. Both the transmembrane domains (TMDs) and the N-terminal cytoplasmic domain (NTD) are involved in regulation of AE2 activity. However, the regulatory mechanism remains unclear. Here, we report a 3.2 Å cryo-EM structure of the AE2 TMDs in complex with PIP2 and a 3.3 Å full-length mutant AE2 structure in the resting state without PIP2. We demonstrate that PIP2 at the TMD dimer interface is involved in the substrate exchange process. Mutation in the PIP2 binding site leads to the displacement of TM7 and further stabilizes the interaction between the TMD and the NTD. Reduced substrate transport activity and conformation similar to AE2 in acidic pH indicating the central contribution of PIP2 to the function of AE2.
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Affiliation(s)
- Weiqi Zhang
- Institute of Systems Biomedicine, Department of Pathology, Beijing Key Laboratory of Tumor Systems Biology, Peking-Tsinghua Center for Life Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Dian Ding
- Institute of Systems Biomedicine, Department of Pathology, Beijing Key Laboratory of Tumor Systems Biology, Peking-Tsinghua Center for Life Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Yishuo Lu
- Institute of Systems Biomedicine, Department of Pathology, Beijing Key Laboratory of Tumor Systems Biology, Peking-Tsinghua Center for Life Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Hongyi Chen
- Institute of Systems Biomedicine, Department of Pathology, Beijing Key Laboratory of Tumor Systems Biology, Peking-Tsinghua Center for Life Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Peijun Jiang
- Institute of Systems Biomedicine, Department of Pathology, Beijing Key Laboratory of Tumor Systems Biology, Peking-Tsinghua Center for Life Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Peng Zuo
- Institute of Systems Biomedicine, Department of Pathology, Beijing Key Laboratory of Tumor Systems Biology, Peking-Tsinghua Center for Life Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Guangxi Wang
- Institute of Systems Biomedicine, Department of Pathology, Beijing Key Laboratory of Tumor Systems Biology, Peking-Tsinghua Center for Life Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Juan Luo
- Institute of Precision Medicine, Peking University Shenzhen Hospital, Shenzhen, 518036, China
| | - Yue Yin
- Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Jianyuan Luo
- Department of Medical Genetics, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Yuxin Yin
- Institute of Systems Biomedicine, Department of Pathology, Beijing Key Laboratory of Tumor Systems Biology, Peking-Tsinghua Center for Life Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China.
- Institute of Precision Medicine, Peking University Shenzhen Hospital, Shenzhen, 518036, China.
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6
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Fasham J, Huebner AK, Liebmann L, Khalaf-Nazzal R, Maroofian R, Kryeziu N, Wortmann SB, Leslie JS, Ubeyratna N, Mancini GMS, van Slegtenhorst M, Wilke M, Haack TB, Shamseldin HE, Gleeson JG, Almuhaizea M, Dweikat I, Abu-Libdeh B, Daana M, Zaki MS, Wakeling MN, McGavin L, Turnpenny PD, Alkuraya FS, Houlden H, Schlattmann P, Kaila K, Crosby AH, Baple EL, Hübner CA. SLC4A10 mutation causes a neurological disorder associated with impaired GABAergic transmission. Brain 2023; 146:4547-4561. [PMID: 37459438 PMCID: PMC10629776 DOI: 10.1093/brain/awad235] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/19/2023] [Accepted: 06/06/2023] [Indexed: 11/09/2023] Open
Abstract
SLC4A10 is a plasma-membrane bound transporter that utilizes the Na+ gradient to drive cellular HCO3- uptake, thus mediating acid extrusion. In the mammalian brain, SLC4A10 is expressed in principal neurons and interneurons, as well as in epithelial cells of the choroid plexus, the organ regulating the production of CSF. Using next generation sequencing on samples from five unrelated families encompassing nine affected individuals, we show that biallelic SLC4A10 loss-of-function variants cause a clinically recognizable neurodevelopmental disorder in humans. The cardinal clinical features of the condition include hypotonia in infancy, delayed psychomotor development across all domains and intellectual impairment. Affected individuals commonly display traits associated with autistic spectrum disorder including anxiety, hyperactivity and stereotyped movements. In two cases isolated episodes of seizures were reported in the first few years of life, and a further affected child displayed bitemporal epileptogenic discharges on EEG without overt clinical seizures. While occipitofrontal circumference was reported to be normal at birth, progressive postnatal microcephaly evolved in 7 out of 10 affected individuals. Neuroradiological features included a relative preservation of brain volume compared to occipitofrontal circumference, characteristic narrow sometimes 'slit-like' lateral ventricles and corpus callosum abnormalities. Slc4a10 -/- mice, deficient for SLC4A10, also display small lateral brain ventricles and mild behavioural abnormalities including delayed habituation and alterations in the two-object novel object recognition task. Collapsed brain ventricles in both Slc4a10-/- mice and affected individuals suggest an important role of SLC4A10 in the production of the CSF. However, it is notable that despite diverse roles of the CSF in the developing and adult brain, the cortex of Slc4a10-/- mice appears grossly intact. Co-staining with synaptic markers revealed that in neurons, SLC4A10 localizes to inhibitory, but not excitatory, presynapses. These findings are supported by our functional studies, which show the release of the inhibitory neurotransmitter GABA is compromised in Slc4a10-/- mice, while the release of the excitatory neurotransmitter glutamate is preserved. Manipulation of intracellular pH partially rescues GABA release. Together our studies define a novel neurodevelopmental disorder associated with biallelic pathogenic variants in SLC4A10 and highlight the importance of further analyses of the consequences of SLC4A10 loss-of-function for brain development, synaptic transmission and network properties.
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Affiliation(s)
- James Fasham
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
- Peninsula Clinical Genetics Service, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Antje K Huebner
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, 07747 Jena, Germany
| | - Lutz Liebmann
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, 07747 Jena, Germany
| | - Reham Khalaf-Nazzal
- Department of Biomedical Sciences, Faculty of Medicine, Arab American University of Palestine, Jenin, P227, Palestine
| | - Reza Maroofian
- Molecular and Clinical Sciences Institute, St. George’s University of London, London SW17 0RE, UK
| | - Nderim Kryeziu
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, 07747 Jena, Germany
| | - Saskia B Wortmann
- University Children’s Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), 5020 Salzburg, Austria
- Amalia Children’s Hospital, Radboudumc, 6525 GA Nijmegen, The Netherlands
- Institute of Human Genetics, Technische Universität München, 80333 Munich, Germany
| | - Joseph S Leslie
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Nishanka Ubeyratna
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Grazia M S Mancini
- Department of Clinical Genetics, Erasmus Medical Center, 3015 GD Rotterdam, The Netherlands
| | | | - Martina Wilke
- Department of Clinical Genetics, Erasmus Medical Center, 3015 GD Rotterdam, The Netherlands
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, 72076 Tübingen, Germany
| | - Hanan E Shamseldin
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh 11564, Saudi Arabia
| | - Joseph G Gleeson
- Rady Children’s Institute for Genomic Medicine, San Diego, CA 92123, USA
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mohamed Almuhaizea
- Department of Neuroscience, King Faisal Specialist Hospital and Research Center, Riyadh 11564, Saudi Arabia
| | - Imad Dweikat
- Department of Biomedical Sciences, Faculty of Medicine, Arab American University of Palestine, Jenin, P227, Palestine
| | - Bassam Abu-Libdeh
- Department of Pediatrics and Genetics, Makassed Hospital and Al-Quds University, East Jerusalem, 95908, Palestine
| | - Muhannad Daana
- Department of Pediatrics, Arab Women’s Union Hospital, Nablus, P400, Palestine
| | - Maha S Zaki
- Clinical Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Dokki, Cairo 12622, Egypt
| | - Matthew N Wakeling
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Lucy McGavin
- Department of Radiology, Derriford Hospital, Plymouth PL6 8DH, UK
| | - Peter D Turnpenny
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
- Peninsula Clinical Genetics Service, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Fowzan S Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh 11564, Saudi Arabia
| | - Henry Houlden
- Molecular and Clinical Sciences Institute, St. George’s University of London, London SW17 0RE, UK
| | - Peter Schlattmann
- Institute for Medical Statistics, Computer Science and Data Science, Jena University Hospital, 07747 Jena, Germany
| | - Kai Kaila
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Andrew H Crosby
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Emma L Baple
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
- Peninsula Clinical Genetics Service, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Christian A Hübner
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, 07747 Jena, Germany
- Center for Rare Diseases, Jena University Hospital, Friedrich Schiller Universität, 07747 Jena, Germany
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7
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Kui M, Pluznick JL, Zaidman NA. The transcription factor Foxi1 promotes expression of V-ATPase and Gpr116 in M-1 cells. Am J Physiol Renal Physiol 2023; 324:F267-F273. [PMID: 36603001 PMCID: PMC9942906 DOI: 10.1152/ajprenal.00272.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/22/2022] [Accepted: 12/22/2022] [Indexed: 01/06/2023] Open
Abstract
The diverse functions of each nephron segment rely on the coordinated action of specialized cell populations that are uniquely defined by their transcriptional profile. In the collecting duct, there are two critical and distinct cell populations: principal cells and intercalated cells. Principal cells play key roles in the regulation of water, Na+, and K+, whereas intercalated cells are best known for their role in acid-base homeostasis. Currently, there are no in vitro systems that recapitulate the heterogeneity of the collecting ducts, which limits high-throughput and replicate investigations of genetic and physiological phenomena. Here, we demonstrated that the transcription factor Foxi1 is sufficient to alter the transcriptional identity of M-1 cells, a murine cortical collecting duct cell line. Specifically, overexpression of Foxi1 induces the expression of intercalated cell transcripts including Gpr116, Atp6v1b1, Atp6v1g3, Atp6v0d2, Slc4a9, and Slc26a4. These data indicate that overexpression of Foxi1 differentiates M-1 cells toward a non-A, non-B type intercalated cell phenotype and may provide a novel in vitro tool to study transcriptional regulation and physiological function of the renal collecting duct.NEW & NOTEWORTHY Transfection of M-1 cells with the transcription factor Foxi1 generates cells that express V-ATPase and Gpr116 as well as other genes associated with renal intercalated cells. This straightforward and novel in vitro system could be used to study processes including transcriptional regulation and cell specification and differentiation in renal intercalated cells.
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Affiliation(s)
- Mackenzie Kui
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Jennifer L Pluznick
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Nathan A Zaidman
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
- Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States
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8
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Xue JY, Ikegawa S, Guo L. SLC4A2, another gene involved in acid-base balancing machinery of osteoclasts, causes osteopetrosis. Bone 2023; 167:116603. [PMID: 36343920 DOI: 10.1016/j.bone.2022.116603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/30/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022]
Abstract
SLC4A2 belongs to the Na+-independent solute carrier family 4 (SLC4) of anion exchangers, which regulate electroneutral exchange of Cl- for HCO3- and mediate intra- and extra-cellular pH, chloride concentration and cell volume. Slc4a2 also participates in gastric acid secretion, spermatogenesis and osteoclastogenesis. During osteoclast differentiation, Slc4a2 is exclusively expressed at the contra-lacunar membrane and is up-regulated with osteoclast maturation. Bi-allelic Slc4a2 loss-of-function mutations have been known to cause osteopetrosis in mice and cattle, but not in human. Recently, we have identified bi-allelic pathogenic variants in SLC4A2 in a patient affected by osteopetrosis with severe renal insufficiency, suggesting SLC4A2 deficiency causes a new type of autosomal recessive osteopetrosis (osteopetrosis, Ikegawa type). In this article, we review the advances in exploring the multiple functions of SLC4A2 with emphasis on its roles in osteoclast. Our review would contribute to understanding of the phenotypic spectrum and the pathomechanism of SLC4A2-associated osteopetrosis.
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Affiliation(s)
- Jing-Yi Xue
- Shaanxi Institute for Pediatric Diseases, Xi'an Children's Hospital, Affiliated Children's Hospital of Xi'an Jiaotong University, Xi'an 710082, China
| | - Shiro Ikegawa
- Laboratory for Bone and Joint Diseases, RIKEN Center for Integrative Medical Sciences, Tokyo 108-8639, Japan
| | - Long Guo
- Shaanxi Institute for Pediatric Diseases, Xi'an Children's Hospital, Affiliated Children's Hospital of Xi'an Jiaotong University, Xi'an 710082, China; Department of Laboratory Animal Science, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China.
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9
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Handelman SK, Puentes YM, Kuppa A, Chen Y, Du X, Feitosa MF, Palmer ND, Speliotes EK. Population-based meta-analysis and gene-set enrichment identifies FXR/RXR pathway as common to fatty liver disease and serum lipids. Hepatol Commun 2022; 6:3120-3131. [PMID: 36098472 PMCID: PMC9592792 DOI: 10.1002/hep4.2066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/15/2022] [Accepted: 07/19/2022] [Indexed: 02/03/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is prevalent worldwide. NAFLD is associated with elevated serum triglycerides (TG), low-density lipoprotein cholesterol (LDL), and reduced high-density lipoprotein cholesterol (HDL). Both NAFLD and blood lipid levels are genetically influenced and may share a common genetic etiology. We used genome-wide association studies (GWAS)-ranked genes and gene-set enrichment analysis to identify pathways that affect serum lipids and NAFLD. We identified credible genes in these pathways and characterized missense variants in these for effects on serum traits. We used MAGENTA to identify 58 enriched pathways from publicly available TG, LDL, and HDL GWAS (n = 99,000). Three of these pathways were also enriched for associations with European-ancestry NAFLD GWAS (n = 7176). One pathway, farnesoid X receptor (FXR)/retinoid X receptor (RXR) activation, was replicated for association in an African-ancestry NAFLD GWAS (n = 3214) and plays a role in serum lipids and NAFLD. Credible genes (proteins) in FXR/RXR activation include those associated with cholesterol/bile/bilirubin transport/absorption (ABCC2 (MRP2) [ATP binding cassette subfamily C member (multidrug resistance-associated protein 2)], ABCG5, ABCG8 [ATP-binding cassette (ABC) transporters G5 and G8], APOB (APOB) [apolipoprotein B], FABP6 (ILBP) [fatty acid binding protein 6 (ileal lipid-binding protein)], MTTP (MTP) [microsomal triglyceride transfer protein], SLC4A2 (AE2) [solute carrier family 4 member 2 (anion exchange protein 2)]), nuclear hormone-mediated control of metabolism (NR0B2 (SHP) [nuclear receptor subfamily 0 group B member 2 (small heterodimer partner)], NR1H4 (FXR) [nuclear receptor subfamily 1 group H member 4 (FXR)], PPARA (PPAR) [peroxisome proliferator activated receptor alpha], FOXO1 (FOXO1A) [forkhead box O1]), or other pathways (FETUB (FETUB) [fetuin B]). Missense variants in ABCC2 (MRP2), ABCG5 (ABCG5), ABCG8 (ABCG8), APOB (APOB), MTTP (MTP), NR0B2 (SHP), NR1H4 (FXR), and PPARA (PPAR) that associate with serum LDL levels also associate with serum liver function tests in UK Biobank. Conclusion: Genetic variants in NR1H4 (FXR) that protect against liver steatosis increase serum LDL cholesterol while variants in other members of the family have congruent effects on these traits. Human genetic pathway enrichment analysis can help guide therapeutic development by identifying effective targets for NAFLD/serum lipid manipulation while minimizing side effects. In addition, missense variants could be used in companion diagnostics to determine their influence on drug effectiveness.
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Affiliation(s)
- Samuel K. Handelman
- Division of Gastroenterology and HepatologyUniversity of Michigan Health SystemAnn ArborMichiganUSA
| | - Yindra M. Puentes
- Division of Gastroenterology and HepatologyUniversity of Michigan Health SystemAnn ArborMichiganUSA
- Department of Computational Medicine and BioinformaticsUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - Annapurna Kuppa
- Division of Gastroenterology and HepatologyUniversity of Michigan Health SystemAnn ArborMichiganUSA
| | - Yanhua Chen
- Division of Gastroenterology and HepatologyUniversity of Michigan Health SystemAnn ArborMichiganUSA
| | - Xiaomeng Du
- Division of Gastroenterology and HepatologyUniversity of Michigan Health SystemAnn ArborMichiganUSA
| | - Mary F. Feitosa
- Division of Statistical Genomics, Department of GeneticsWashington UniversitySt. LouisMissouriUSA
| | - Nicholette D. Palmer
- Department of BiochemistryWake Forest School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Elizabeth K. Speliotes
- Division of Gastroenterology and HepatologyUniversity of Michigan Health SystemAnn ArborMichiganUSA
- Department of Computational Medicine and BioinformaticsUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
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10
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Peña-Münzenmayer G, Kondo Y, Salinas C, Sarmiento J, Brauchi S, Catalán MA. Activation of the Ae4 (Slc4a9) cation-driven Cl -/HCO 3- exchanger by the cAMP-dependent protein kinase in salivary gland acinar cells. Am J Physiol Gastrointest Liver Physiol 2021; 321:G628-G638. [PMID: 34585968 PMCID: PMC8887885 DOI: 10.1152/ajpgi.00145.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 09/24/2021] [Accepted: 09/27/2021] [Indexed: 01/31/2023]
Abstract
Ae4 transporters are critical for Cl- uptake across the basolateral membrane of acinar cells in the submandibular gland (SMG). Although required for fluid secretion, little is known about the physiological regulation of Ae4. To investigate whether Ae4 is regulated by the cAMP-dependent signaling pathway, we measured Cl-/HCO3- exchanger activity in SMG acinar cells from Ae2-/- mice, which only express Ae4, and found that the Ae4-mediated activity was increased in response to β-adrenergic receptor stimulation. Moreover, pretreatment with H89, an inhibitor of the cAMP-activated kinase (PKA), prevented the stimulation of Ae4 exchangers. We then expressed Ae4 in CHO-K1 cells and found that the Ae4-mediated activity was increased when Ae4 is coexpressed with the catalytic subunit of PKA (PKAc), which is constitutively active. Ae4 sequence analysis showed two potential PKA phosphorylation serine residues located at the intracellular NH2-terminal domain according to a homology model of Ae4. NH2-terminal domain Ser residues were mutated to alanine (S173A and S273A, respectively), where the Cl-/HCO3- exchanger activity displayed by the mutant S173A was not activated by PKA. Conversely, S273A mutant kept the PKA dependency. Together, we conclude that Ae4 is stimulated by PKA in SMG acinar cells by a mechanism that probably depends on the phosphorylation of S173.NEW & NOTEWORTHY We found that Ae4 exchanger activity in secretory salivary gland acinar cells is increased upon β-adrenergic receptor stimulation. The activation of Ae4 was prevented by H89, a nonselective PKA inhibitor. Protein sequence analysis revealed two residues (S173 and S273) that are potential targets of cAMP-dependent protein kinase (PKA). Experiments in CHO-K1 cells expressing S173A and S273A mutants showed that S173A, but not S273A, is not activated by PKA.
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Affiliation(s)
- Gaspar Peña-Münzenmayer
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Valdivia, Chile
| | - Yusuke Kondo
- Division of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Fukuoka, Japan
| | - Constanza Salinas
- Facultad de Medicina, Instituto de Fisiología, Universidad Austral de Chile, Valdivia, Chile
| | - José Sarmiento
- Facultad de Medicina, Instituto de Fisiología, Universidad Austral de Chile, Valdivia, Chile
| | - Sebastián Brauchi
- Facultad de Medicina, Instituto de Fisiología, Universidad Austral de Chile, Valdivia, Chile
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Valdivia, Chile
| | - Marcelo A Catalán
- Facultad de Ciencias de la Salud, Universidad Arturo Prat, Iquique, Chile
- Facultad de Medicina, Instituto de Fisiología, Universidad Austral de Chile, Valdivia, Chile
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11
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Korsós MM, Bellák T, Becskeházi E, Gál E, Veréb Z, Hegyi P, Venglovecz V. Mouse organoid culture is a suitable model to study esophageal ion transport mechanisms. Am J Physiol Cell Physiol 2021; 321:C798-C811. [PMID: 34524930 DOI: 10.1152/ajpcell.00295.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/08/2021] [Indexed: 11/22/2022]
Abstract
Altered esophageal ion transport mechanisms play a key role in inflammatory and cancerous diseases of the esophagus, but epithelial ion processes have been less studied in the esophagus because of the lack of a suitable experimental model. In this study, we generated three-dimensional (3D) esophageal organoids (EOs) from two different mouse strains and characterized the ion transport processes of the EOs. EOs form a cell-filled structure with a diameter of 250-300 µm and were generated from epithelial stem cells as shown by FACS analysis. Using conventional PCR and immunostaining, the presence of Slc26a6 Cl-/HCO3- anion exchanger (AE), Na+/H+ exchanger (NHE), Na+/HCO3- cotransporter (NBC), cystic fibrosis transmembrane conductance regulator (CFTR), and anoctamin 1 Cl- channels was detected in EOs. Microfluorimetric techniques revealed high NHE, AE, and NBC activities, whereas that of CFTR was relatively low. In addition, inhibition of CFTR led to functional interactions between the major acid-base transporters and CFTR. We conclude that EOs provide a relevant and suitable model system for studying the ion transport mechanisms of esophageal epithelial cells, and they can be also used as preclinical tools to assess the effectiveness of novel therapeutic compounds in esophageal diseases associated with altered ion transport processes.
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Affiliation(s)
| | - Tamás Bellák
- Department of Anatomy, Histology and Embryology, University of Szeged, Szeged, Hungary
- BioTalentum Ltd., Gödöllő, Hungary
| | - Eszter Becskeházi
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Eleonóra Gál
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Zoltán Veréb
- Regenerative Medicine and Cellular Pharmacology Research Laboratory, Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Péter Hegyi
- First Department of Medicine, University of Szeged, Szeged, Hungary
- Szentágothai Research Centre, Institute for Translational Medicine, Medical School, University of Pécs, Pécs, Hungary
- Division of Gastroenterology, First Department of Medicine, Medical School, University of Pécs, Pécs, Hungary
| | - Viktória Venglovecz
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
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12
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Yan W, Xiao Y, Zhang Y, Tao Y, Cao Y, Liu K, Cai W, Wang Y. Monogenic mutations in four cases of neonatal-onset watery diarrhea and a mutation review in East Asia. Orphanet J Rare Dis 2021; 16:383. [PMID: 34503561 PMCID: PMC8427875 DOI: 10.1186/s13023-021-01995-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 07/25/2021] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Infants with neonatal-onset diarrhea present with intractable diarrhea in the first few weeks of life. A monogenic mutation is one of the disease etiologies and the use of next-generation sequencing (NGS) has made it possible to screen patients for their mutations. MAIN BODY We retrospectively reviewed the clinical data of four children from unrelated families, who presented with neonatal-onset, chronic, watery, non-bloody diarrhea. After genetic whole-exome sequencing, novel mutations were identified in the EPCAM gene of two children. Congenital chloride diarrhea was diagnosed in one case, which was associated with an SLC26A3 mutation, in which the patient presented with watery diarrhea, malnutrition, and hypochloremic alkalosis. Patient 4 was diagnosed with microvillus inclusion disease and possessed novel compound heterozygous mutations in the MYO5B gene. A review of the genetic variants of SLC26A3 reported in East Asia revealed that c.269_270 dupAA (p.G91Kfs*3) is the most frequent SLC26A3 mutation in China, compared with c.2063-1 G > T in Japan and Korea. EPCAM and MYO5B genetic variants were only sporadically reported in East Asia. CONCLUSION This study expands our knowledge of the clinical manifestations and molecular genetics of neonatal-onset watery diarrhea. Early diagnosis could be achieved by genomic analysis in those infants whose histology features are not typical. The discovery of four novel mutations in the EPCAM gene and two novel mutations in the MYO5B gene provides further etiological evidence for the association of genetic mutations with neonatal-onset diarrhea. To date, c.269_270 dupAA is the most frequent SLC26A3 mutation in China.
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Affiliation(s)
- Weihui Yan
- Division of Pediatric Gastroenterology and Nutrition, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai, People's Republic of China
- Innovative Research Team of High-Level Local Universities in Shanghai, Shanghai, People's Republic of China
| | - Yongtao Xiao
- Shanghai Institute for Pediatric Research, Shanghai, People's Republic of China
- Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai, People's Republic of China
- Innovative Research Team of High-Level Local Universities in Shanghai, Shanghai, People's Republic of China
| | - Yunyi Zhang
- Shanghai Institute for Pediatric Research, Shanghai, People's Republic of China
- Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai, People's Republic of China
| | - Yijing Tao
- Division of Pediatric Gastroenterology and Nutrition, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Yi Cao
- Division of Pediatric Gastroenterology and Nutrition, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Kunhui Liu
- Department of Pediatric Surgery, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Wei Cai
- Shanghai Institute for Pediatric Research, Shanghai, People's Republic of China.
- Department of Pediatric Surgery, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
- Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai, People's Republic of China.
- Innovative Research Team of High-Level Local Universities in Shanghai, Shanghai, People's Republic of China.
- Xinhua Hospital Affiliated To Shanghai Jiao Tong University School of Medicine, No.1665, Kong Jiang Road, Yangpu, Shanghai, 200092, People's Republic of China.
| | - Ying Wang
- Division of Pediatric Gastroenterology and Nutrition, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
- Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai, People's Republic of China.
- Innovative Research Team of High-Level Local Universities in Shanghai, Shanghai, People's Republic of China.
- Xinhua Hospital Affiliated To Shanghai Jiao Tong University School of Medicine, No.1665, Kong Jiang Road, Yangpu, Shanghai, 200092, People's Republic of China.
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13
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Tanimura Y, Kiriya M, Kawashima A, Mori H, Luo Y, Kondo T, Suzuki K. Regulation of solute carrier family 26 member 7 (Slc26a7) by thyroid stimulating hormone in thyrocytes. Endocr J 2021; 68:691-699. [PMID: 33583874 DOI: 10.1507/endocrj.ej20-0502] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Iodine transportation is an important step in thyroid hormone biosynthesis. Uptake of iodine into the thyroid follicle is mediated mainly by the basolateral sodium-iodide symporter (NIS or solute carrier family 5 member 5: SLC5A5), and iodine efflux across the apical membrane into the follicular lumen is mediated by pendrin (SLC26A4). In addition to these transporters, SLC26A7, which has recently been identified as a causative gene for congenital hypothyroidism, was found to encode a novel apical iodine transporter in the thyroid. Although SLC5A5 and SLC26A4 have been well-characterized, little is known about SLC26A7, including its regulation by TSH, the central hormone regulator of thyroid function. Using rat thyroid FRTL-5 cells, we showed that the mRNA levels of Slc26a7 and Slc26a4, two apical iodine transporters responsible for iodine efflux, were suppressed by TSH, whereas the mRNA level of Slc5a5 was induced. Forskolin and dibutyryl cAMP (dbcAMP) had the same effect as that of TSH on the mRNA levels of these transporters. TSH, forskolin and dbcAMP also had suppressive effects on SLC26A7 promoter activity, as assessed by luciferase reporter gene assays, and protein levels, as determined by Western blot analysis. TSH, forskolin and dbcAMP also induced strong localization of Slc26a7 to the cell membrane according to immunofluorescence staining and confocal laser scanning microscopy. Together, these results suggest that TSH suppresses the expression level of Slc26a7 but induces its accumulation at the cell membrane, where it functions as an iodine transporter.
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Affiliation(s)
- Yuta Tanimura
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Itabashi, Tokyo 173-8605, Japan
- Department of Pathology, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan
| | - Mitsuo Kiriya
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Itabashi, Tokyo 173-8605, Japan
| | - Akira Kawashima
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Itabashi, Tokyo 173-8605, Japan
| | - Hitomi Mori
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Itabashi, Tokyo 173-8605, Japan
| | - Yuqian Luo
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Itabashi, Tokyo 173-8605, Japan
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital and Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing 210008, China
| | - Tetsuo Kondo
- Department of Pathology, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan
| | - Koichi Suzuki
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Itabashi, Tokyo 173-8605, Japan
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Abstract
Objective: Placental iodide transport is necessary for maintaining an adequate iodide supply to the developing fetus. We hypothesized that compounds from the placental barrier can compensate for decreases in maternal iodine intake and normalize fetal iodine levels. Methods: Pregnant rats administered different amounts of iodine (1.24, 2.5, 5, or 10 μg/day) were evaluated on gestational day (gd) 16 and 20. The iodine levels in maternal blood, amniotic fluid (AF), and placental tissue were estimated using As-Ce catalytic spectrophotometry. The protein and/or messenger RNA (mRNA) levels of sodium iodide symporter (NIS), pendrin, alpha-smooth muscle actin (α-SMA), and CD31 in the placental labyrinth, trophoblast cells isolated using laser capture microdissection (LCM), and/or fetomaternal thyroid were detected using immunoblotting, real-time polymerase chain reaction, and/or immunohistochemistry. Results: When iodine intake was reduced, iodine levels in maternal blood gradually decreased; however, placental iodine levels were not significantly different between groups on gd16 and gd20. Minimal changes were observed in AF iodine levels on gd16, and a mild decreasing trend was observed (iodine dose, 10 to 1.24 μg/day) on gd20. NIS protein, which was linearly distributed along the basolateral membrane of maternal-fetal thyroid follicles, gradually increased with decreasing iodine levels. Regarding iodine deficiency in the placental labyrinth on gd16 and gd20, pendrin and glycosylated NIS proteins were significantly upregulated in a dose-dependent manner. However, the mRNA levels were unchanged. Furthermore, the conversion of NIS protein from the nonglycosylated to the glycosylated form increased. In trophoblast cells isolated using LCM, PDS mRNA levels increased in the 1.24-μg/day group on gd16 but not NIS mRNA levels. There was a smaller α-SMA+ area in the labyrinth zone on gd16 and gd20; however, the proportional CD31+ area increased on gd16 and reduced on gd20 with decreased iodine levels. Conclusions: All mechanisms upregulating the expression of iodine transporters and changes in villous stroma and microvessel area in the placental labyrinth can promote iodide transfer from mother to fetus in iodine deficiency, especially before the onset of fetal thyroid function. Compensatory NIS protein regulation in the placenta against decreased iodine intake mainly occurs during translation and glycosylation modification after translation. Pendrin may be more important than NIS in the mediation of placental iodide transport.
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Affiliation(s)
- Yina Sun
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital, Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, P.R. China
| | - Yuanyuan Han
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital, Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, P.R. China
- Clinical Psychology Department, Weifang People's Hospital, Weifang, P.R. China
| | - Ming Qian
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital, Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, P.R. China
- Department of Medical Psychology, Tianjin Medical University, Tianjin, P.R. China
| | - Yongmei Li
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital, Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, P.R. China
| | - Yan Ye
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital, Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, P.R. China
| | - Laixiang Lin
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital, Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, P.R. China
| | - Yuanjun Liu
- Department of Dermatovenereology, Tianjin Medical University General Hospital, Tianjin, P.R. China
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Kumar A, Priyamvada S, Ge Y, Jayawardena D, Singhal M, Anbazhagan AN, Chatterjee I, Dayal A, Patel M, Zadeh K, Saksena S, Alrefai WA, Gill RK, Zadeh M, Zhao N, Mohamadzadeh M, Dudeja PK. A Novel Role of SLC26A3 in the Maintenance of Intestinal Epithelial Barrier Integrity. Gastroenterology 2021; 160:1240-1255.e3. [PMID: 33189700 PMCID: PMC7956241 DOI: 10.1053/j.gastro.2020.11.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 11/02/2020] [Accepted: 11/03/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS The down-regulated in adenoma (DRA) protein, encoded by SLC26A3, a key intestinal chloride anion exchanger, has recently been identified as a novel susceptibility gene for inflammatory bowel disease (IBD). However, the mechanisms underlying the increased susceptibility to inflammation induced by the loss of DRA remain elusive. Compromised barrier is a key event in IBD pathogenesis. The current studies were undertaken to elucidate the impact of DRA deficiency on epithelial barrier integrity and to define underlying mechanisms. METHODS Wild-type and DRA-knockout (KO) mice and crypt-derived colonoids were used as models for intestinal epithelial response. Paracellular permeability was measured by using fluorescein isothiocyanate-dextran flux. Immunoblotting, immunofluorescence, immunohistochemistry, and ribonucleoprotein immunoprecipitation assays were performed. Gut microbiome analysis was conducted to investigate the impact of DRA deficiency on gut microbial communities. RESULTS DRA-KO mice exhibited an increased colonic paracellular permeability with significantly decreased levels of tight junction/adherens junction proteins, including ZO-1, occludin, and E-cadherin. A similar expression pattern of occludin and E-cadherin was observed in colonoids derived from DRA-KO mice and short hairpin RNA-mediated DRA knockdown in Caco-2 cells. Microbial analysis showed gut dysbiosis in DRA-KO mice. However, cohousing studies showed that dysbiosis played only a partial role in maintaining tight junction protein expression. Furthermore, our results showed increased binding of RNA-binding protein CUGBP1 with occludin and E-cadherin genes in DRA-KO mouse colon, suggesting that posttranscriptional mechanisms play a key role in gut barrier dysfunction. CONCLUSIONS To our knowledge, our studies demonstrate a novel role of DRA in maintaining the intestinal epithelial barrier function and potential implications of its dysregulation in IBD pathogenesis.
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Affiliation(s)
- Anoop Kumar
- Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Shubha Priyamvada
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Yong Ge
- Department of Infectious Diseases and Immunology and Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Florida, Gainesville, Florida
| | - Dulari Jayawardena
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Megha Singhal
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Arivarasu N Anbazhagan
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Ishita Chatterjee
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Aneal Dayal
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Mitul Patel
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Kimia Zadeh
- Department of Infectious Diseases and Immunology and Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Florida, Gainesville, Florida
| | - Seema Saksena
- Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Waddah A Alrefai
- Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Ravinder K Gill
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Mojgan Zadeh
- Department of Infectious Diseases and Immunology and Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Florida, Gainesville, Florida
| | - Ni Zhao
- Department of Infectious Diseases and Immunology and Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Florida, Gainesville, Florida
| | - Mansour Mohamadzadeh
- Department of Infectious Diseases and Immunology and Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Florida, Gainesville, Florida
| | - Pradeep K Dudeja
- Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.
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Sarkar D, Chandra AK, Chattopadyay S, Biswas M, Das S, Singh LH, Ray I. Possible mechanism of bamboo shoots ( Bambusa balcooa) induced thyroid disruption - An in vitro study. Hum Exp Toxicol 2021; 40:483-496. [PMID: 32909866 DOI: 10.1177/0960327120958037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Endemic goitre and associated iodine deficiency disorders (IDDs) are a major concern in public health even in the period of post salt iodization in many regions. Among others the consumption of cyanogenic plants found responsible for the persistence of such diseases. Bamboo shoots (BS) is one such cyanogenic plant food that caused disruption of certain thyroid hormone synthesizing regulatory element as has already been reported in our earlier study. In this investigation the possible mechanism of thyrocytes disruption along with interruption of thyroid hormone biosynthesis by BS has been worked out. Commonly consumed BS, Bambusa Balcooa Roxb (BBR) water extract was analysed by GC MS; three doses below IC50 were administered to thyrocytes in culture with and without iodine. Expressions of thyroglobulin (Tg), pendrin (PDS) and monocarboxylate transporter 8 (MCT8) were evaluated in thyrocytes with cell cycle analysis, reactive oxygen species (ROS) generation, DNA oxidation and apoptotic regulation through Bax, Bcl-2 and p53. Phytochemical analysis of BBR extract revealed the presence of precursors and metabolic end products of cyanogenic glycosides. Dose dependent decrease in expression of Tg and PDS with concomitant decrease in gene expression of these with MCT8 were observed. Increased ROS, DNA oxidation and associated imbalance were found through increased Bax and p53 with decreased Bcl-2 that perturbed thyrocytes cell cycle. Cyanogenic constituents of BBR generates ROS associated oxidative changes in thyrocytes with DNA damage and oxidation and cell cycle disruption followed by inhibition of thyroid hormone synthesizing regulatory elements; addition of extra iodine showed partial prevention.
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Affiliation(s)
- D Sarkar
- Department of Physiology, 30163University of Calcutta, Kolkata, West Bengal, India
| | - A K Chandra
- Department of Physiology, 30163University of Calcutta, Kolkata, West Bengal, India
| | - S Chattopadyay
- Department of Physiology, 30163University of Calcutta, Kolkata, West Bengal, India
| | - M Biswas
- Department of Botany, 30163University of Calcutta, Kolkata, West Bengal, India
| | - S Das
- Department of Botany, 30163University of Calcutta, Kolkata, West Bengal, India
| | - L H Singh
- Department of Zoology, 179227DM College of Science (Govt. of Manipur), Imphal West, Manipur, India
| | - I Ray
- Department of Human Physiology, Ramkrishna Mahavidyalaya (Govt. of Tripura), Unakoti, Tripura, India
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Priyamvada S, Anbazhagan AN, Kumar A, Chatterjee I, Borthakur A, Saksena S, Gill RK, Alrefai WA, Dudeja PK. All-trans Retinoic Acid Counteracts Diarrhea and Inhibition of Downregulated in Adenoma Expression in Gut Inflammation. Inflamm Bowel Dis 2020; 26:534-545. [PMID: 31634391 PMCID: PMC7456978 DOI: 10.1093/ibd/izz249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND Intestinal epithelial apical membrane Cl-/HCO3- exchanger DRA (downregulated in adenoma, SLC26A3) has emerged as an important therapeutic target for diarrhea, emphasizing the potential therapeutic role of agents that upregulate DRA. All-trans retinoic acid (ATRA), a key vitamin A metabolite, was earlier shown by us to stimulate DRA expression in intestinal epithelial cells. However, its role in modulating DRA in gut inflammation has not been investigated. AIMS Our aim was to analyze the efficacy of ATRA in counteracting inflammation-induced decrease in DRA in vitro and in vivo. METHODS Interferon-γ (IFN-γ)-treated Caco-2 cells and dextran sulfate sodium (DSS)-treated C57BL/6J mice served as in vitro and in vivo models of gut inflammation, respectively. The effect of ATRA on IFN-γ-mediated inhibition of DRA function, expression, and promoter activity were elucidated. In the DSS colitis model, diarrheal phenotype, cytokine response, in vivo imaging, myeloperoxidase activity, and DRA expression were measured in the distal colon. RESULTS All-trans retinoic acid (10 μM, 24 h) abrogated IFN-γ (30 ng/mL, 24 h)-induced decrease in DRA function, expression, and promoter activity in Caco-2 cells. All-trans retinoic acid altered IFN-γ signaling via blocking IFN-γ-induced tyrosine phosphorylation of STAT-1. All-trans retinoic acid cotreatment (1 mg/kg BW, i.p. daily) of DSS-treated mice (3% in drinking water for 7 days) alleviated colitis-associated weight loss, diarrheal phenotype, and induction of IL-1β and CXCL1 and a decrease in DRA mRNA and protein levels in the colon. CONCLUSION Our data showing upregulation of DRA under normal and inflammatory conditions by ATRA demonstrate a novel role of this micronutrient in alleviating IBD-associated diarrhea.
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Affiliation(s)
- Shubha Priyamvada
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Arivarasu N Anbazhagan
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Anoop Kumar
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Ishita Chatterjee
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Alip Borthakur
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Seema Saksena
- Jesse Brown Veterans Affairs Medical Center, Chicago, IL, USA
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Ravinder K Gill
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Waddah A Alrefai
- Jesse Brown Veterans Affairs Medical Center, Chicago, IL, USA
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Pradeep K Dudeja
- Jesse Brown Veterans Affairs Medical Center, Chicago, IL, USA
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
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18
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Wasano K, Takahashi S, Rosenberg SK, Kojima T, Mutai H, Matsunaga T, Ogawa K, Homma K. Systematic quantification of the anion transport function of pendrin (SLC26A4) and its disease-associated variants. Hum Mutat 2020; 41:316-331. [PMID: 31599023 PMCID: PMC6930342 DOI: 10.1002/humu.23930] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 10/01/2019] [Accepted: 10/03/2019] [Indexed: 01/14/2023]
Abstract
Thanks to the advent of rapid DNA sequencing technology and its prevalence, many disease-associated genetic variants are rapidly identified in many genes from patient samples. However, the subsequent effort to experimentally validate and define their pathological roles is extremely slow. Consequently, the pathogenicity of most disease-associated genetic variants is solely speculated in silico, which is no longer deemed compelling. We developed an experimental approach to efficiently quantify the pathogenic effects of disease-associated genetic variants with a focus on SLC26A4, which is essential for normal inner ear function. Alterations of this gene are associated with both syndromic and nonsyndromic hereditary hearing loss with various degrees of severity. We established HEK293T-based stable cell lines that express pendrin missense variants in a doxycycline-dependent manner, and systematically determined their anion transport activities with high accuracy in a 96-well plate format using a high throughput plate reader. Our doxycycline dosage-dependent transport assay objectively distinguishes missense variants that indeed impair the function of pendrin from those that do not (functional variants). We also found that some of these putative missense variants disrupt normal messenger RNA splicing. Our comprehensive experimental approach helps determine the pathogenicity of each pendrin variant, which should guide future efforts to benefit patients.
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Affiliation(s)
- Koichiro Wasano
- Department of Otolaryngology – Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Laboratory of Auditory Disorders, Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo 152-8902, Japan
| | - Satoe Takahashi
- Department of Otolaryngology – Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Samuel K. Rosenberg
- Department of Otolaryngology – Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Takashi Kojima
- Department of Otolaryngology – Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Hideki Mutai
- Laboratory of Auditory Disorders, Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo 152-8902, Japan
| | - Tatsuo Matsunaga
- Laboratory of Auditory Disorders, Division of Hearing and Balance Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro, Tokyo 152-8902, Japan
| | - Kaoru Ogawa
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kazuaki Homma
- Department of Otolaryngology – Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- The Hugh Knowles Center for Clinical and Basic Science in Hearing and Its Disorders, Northwestern University, Evanston, IL 60608, USA
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Abdulrahim JW, Kwee LC, Grass E, Siegler IC, Williams R, Karra R, Kraus WE, Gregory SG, Shah SH. Epigenome-Wide Association Study for All-Cause Mortality in a Cardiovascular Cohort Identifies Differential Methylation in Castor Zinc Finger 1 ( CASZ1). J Am Heart Assoc 2019; 8:e013228. [PMID: 31642367 PMCID: PMC6898816 DOI: 10.1161/jaha.119.013228] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 09/23/2019] [Indexed: 02/06/2023]
Abstract
Background DNA methylation is implicated in many chronic diseases and may contribute to mortality. Therefore, we conducted an epigenome-wide association study (EWAS) for all-cause mortality with whole-transcriptome data in a cardiovascular cohort (CATHGEN [Catheterization Genetics]). Methods and Results Cases were participants with mortality≥7 days postcatheterization whereas controls were alive with≥2 years of follow-up. The Illumina Human Methylation 450K and EPIC arrays (Illumina, San Diego, CA) were used for the discovery and validation sets, respectively. A linear model approach with empirical Bayes estimators adjusted for confounders was used to assess difference in methylation (Δβ). In the discovery set (55 cases, 49 controls), 25 629 (6.5%) probes were differently methylated (P<0.05). In the validation set (108 cases, 108 controls), 3 probes were differentially methylated with a false discovery rate-adjusted P<0.10: cg08215811 (SLC4A9; log2 fold change=-0.14); cg17845532 (MATK; fold change=-0.26); and cg17944110 (castor zinc finger 1 [CASZ1]; FC=0.26; P<0.0001; false discovery rate-adjusted P=0.046-0.080). Meta-analysis identified 6 probes (false discovery rate-adjusted P<0.05): the 3 above, cg20428720 (intergenic), cg17647904 (NCOR2), and cg23198793 (CAPN3). Messenger RNA expression of 2 MATK isoforms was lower in cases (fold change=-0.24 [P=0.007] and fold change=-0.61 [P=0.009]). The CASZ1, NCOR2, and CAPN3 transcripts did not show differential expression (P>0.05); the SLC4A9 transcript did not pass quality control. The cg17944110 probe is located within a potential regulatory element; expression of predicted targets (using GeneHancer) of the regulatory element, UBIAD1 (P=0.01) and CLSTN1 (P=0.03), were lower in cases. Conclusions We identified 6 novel methylation sites associated with all-cause mortality. Methylation in CASZ1 may serve as a regulatory element associated with mortality in cardiovascular patients. Larger studies are necessary to confirm these observations.
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Affiliation(s)
- Jawan W. Abdulrahim
- Duke Molecular Physiology InstituteDuke University School of MedicineDuke UniversityDurhamNC
| | - Lydia Coulter Kwee
- Duke Molecular Physiology InstituteDuke University School of MedicineDuke UniversityDurhamNC
| | - Elizabeth Grass
- Duke Molecular Physiology InstituteDuke University School of MedicineDuke UniversityDurhamNC
| | - Ilene C. Siegler
- Department of Psychiatry and Behavioral SciencesDuke UniversityDurhamNC
| | - Redford Williams
- Department of Psychiatry and Behavioral SciencesDuke UniversityDurhamNC
| | - Ravi Karra
- Division of CardiologyDepartment of MedicineDuke University School of MedicineDurhamNC
| | - William E. Kraus
- Duke Molecular Physiology InstituteDuke University School of MedicineDuke UniversityDurhamNC
- Division of CardiologyDepartment of MedicineDuke University School of MedicineDurhamNC
| | - Simon G. Gregory
- Duke Molecular Physiology InstituteDuke University School of MedicineDuke UniversityDurhamNC
| | - Svati H. Shah
- Duke Molecular Physiology InstituteDuke University School of MedicineDuke UniversityDurhamNC
- Division of CardiologyDepartment of MedicineDuke University School of MedicineDurhamNC
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Mukaibo T, Munemasa T, George AT, Tran DT, Gao X, Herche JL, Masaki C, Shull GE, Soleimani M, Melvin JE. The apical anion exchanger Slc26a6 promotes oxalate secretion by murine submandibular gland acinar cells. J Biol Chem 2018; 293:6259-6268. [PMID: 29530983 PMCID: PMC5925796 DOI: 10.1074/jbc.ra118.002378] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/08/2018] [Indexed: 12/15/2022] Open
Abstract
The solute carrier family 26 (SLC26) gene family encodes at least 10 different anion exchangers. SLC26 member 6 (SLC26A6 or CFEX/PAT-1) and the cystic fibrosis transmembrane conductance regulator (CFTR) co-localize to the apical membrane of pancreatic duct cells, where they act in concert to drive HCO3- and fluid secretion. In contrast, in the small intestine, SLC26A6 serves as the major pathway for oxalate secretion. However, little is known about the function of Slc26a6 in murine salivary glands. Here, RNA sequencing-based transcriptional profiling and Western blots revealed that Slc26a6 is highly expressed in mouse submandibular and sublingual salivary glands. Slc26a6 localized to the apical membrane of salivary gland acinar cells with no detectable immunostaining in the ducts. CHO-K1 cells transfected with mouse Slc26a6 exchanged Cl- for oxalate and HCO3-, whereas two other anion exchangers known to be expressed in salivary gland acinar cells, Slc4a4 and Slc4a9, mediated little, if any, Cl-/oxalate exchange. Of note, both Cl-/oxalate exchange and Cl-/HCO3- exchange were significantly reduced in acinar cells isolated from the submandibular glands of Slc26a6-/- mice. Oxalate secretion in submandibular saliva also decreased significantly in Slc26a6-/- mice, but HCO3- secretion was unaffected. Taken together, our findings indicate that Slc26a6 is located at the apical membrane of salivary gland acinar cells, where it mediates Cl-/oxalate exchange and plays a critical role in the secretion of oxalate into saliva.
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Affiliation(s)
- Taro Mukaibo
- From the Secretory Mechanisms and Dysfunctions Section and
- the Department of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Kitakyushu, Fukuoka 803-8580, Japan
| | - Takashi Munemasa
- From the Secretory Mechanisms and Dysfunctions Section and
- the Department of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Kitakyushu, Fukuoka 803-8580, Japan
| | - Alvin T George
- From the Secretory Mechanisms and Dysfunctions Section and
| | - Duy T Tran
- Biological Chemistry Section, NIDCR, National Institutes of Health, Bethesda, Maryland 20892
| | - Xin Gao
- From the Secretory Mechanisms and Dysfunctions Section and
- the Joint Institute for Food Safety and Applied Nutrition, University of Maryland, College Park, Maryland 20742, and
| | - Jesse L Herche
- From the Secretory Mechanisms and Dysfunctions Section and
| | - Chihiro Masaki
- the Department of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Kitakyushu, Fukuoka 803-8580, Japan
| | - Gary E Shull
- Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | | | - James E Melvin
- From the Secretory Mechanisms and Dysfunctions Section and
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Abstract
Heat stress is a problem in laying hens as it decreases egg quality by decreasing eggshell mineralization. Heat stress alters gene expression, hence our aim was to investigate effects of heat stress on gene expression of ion transport elements involving in uterine mineralization (TRPV6, CALB1, ITPR3, SCNN1G, SLC4A4, KCNJ15, SLC4A9, and CLCN2) by real time quantitative PCR. Forty 23-week-old White Leghorn laying hens were housed in two rooms. The control group (n = 20) was maintained at 21-23 °C, and the heat stress group (n = 20) was exposed to 36-38 °C for 8 weeks. All parameters of egg quality including egg weight, surface area, volume, and eggshell weight, thickness, ash weight, and calcium content were decreased in the heat stress group compared to the control group (by 26.9%, 32.7%, 44.1%, 38.4%, 31.7%, 39.4%, and 11.1%, respectively). Total plasma calcium was decreased by 13.4%. Levels of ITPR3, SLC4A4, and SLC4A9 transcripts in the uterine lining were decreased in the heat stress group compared to the control group (by 61.4%, 66.1%, and 66.1%, respectively). CALB1 transcript level was increased (by 34.2 fold) in the heat stress group of hens compared to controls. TRPV6, SCNN1G, KCNJ15, and CLCN2 transcript levels did not significantly differ between control and heat stress groups of laying hens. It is concluded that the down-expression of ITPR3, SLC4A4, and SLC4A9 genes may impair transportation of Cl-, HCO3-, and Na+ in eggshell mineralization during heat stress. Increased CALB1 gene expression may increase resistance of uterine cells to detrimental effects of heat stress.
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Affiliation(s)
- Shahab Bahadoran
- a Department of Clinical Sciences, Faculty of Veterinary Medicine , Shahrekord University , Shahrekord , Iran
| | - Amir Dehghani Samani
- a Department of Clinical Sciences, Faculty of Veterinary Medicine , Shahrekord University , Shahrekord , Iran
| | - Hossein Hassanpour
- b Department of Basic Sciences, Faculty of Veterinary Medicine , Shahrekord University , Shahrekord , Iran
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22
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Kumar A, Chatterjee I, Gujral T, Alakkam A, Coffing H, Anbazhagan AN, Borthakur A, Saksena S, Gill RK, Alrefai WA, Dudeja PK. Activation of Nuclear Factor-κB by Tumor Necrosis Factor in Intestinal Epithelial Cells and Mouse Intestinal Epithelia Reduces Expression of the Chloride Transporter SLC26A3. Gastroenterology 2017; 153:1338-1350.e3. [PMID: 28823863 PMCID: PMC5669803 DOI: 10.1053/j.gastro.2017.08.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 07/26/2017] [Accepted: 08/02/2017] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Diarrhea associated with inflammatory bowel diseases has been associated with increased levels of inflammatory cytokines, including tumor necrosis factor (TNF). The intestinal mucosa of patients with inflammatory bowel diseases has reduced expression of solute carrier family 26 member 3 (SLC26A3, also called DRA). We investigated whether TNF directly affects expression of DRA in human intestinal epithelial cells (IECs) and in the intestines of mice, and studied the mechanisms of these effects. METHODS We performed quantitative reverse transcription polymerase chain reaction, immunofluorescence, and immunoblot analyses in Caco-2, HT-29, and T-84 cells human IECs cultured in 2 or 3 dimensions with or without TNF (50 ng/mL for 6-24 hours). We purified nuclear extracts and quantified nuclear factor-κB (NF-κB) activation and DNA binding. We isolated intestinal crypts from C57BL/6 mice, cultured enteroids, incubated these with TNF (50 ng/mL, 24 hours), and quantified messenger RNAs. DRA-mediated exchange of Cl- for HCO3- was measured by uptake of 125I. Expression of the NF-κB inhibitor α (IkBa) was knocked down in Caco-2 cells with small interfering RNAs. Activation of NF-κB in response to TNF was measured by luciferase reporter assays; binding of the NF-κB subunit p65 in cells was analyzed in chromatin immunoprecipitation assays. DRA promoter activity was measured in a luciferase reporter assay. C57BL/6 mice were injected with TNF (5 μg/mouse for 3-6 hours) or vehicle (control); intestines were collected and analyzed by immunofluorescence, or RNA and protein were collected from the mucosa. RESULTS Incubation of IECs with TNF reduced expression of DRA. Knockdown of NF-κB inhibitor α in IECs led to nuclear translocation of the NF-κB subunit p65 and reduced levels of DRA messenger RNA and protein. Expression of a transgene encoding p65 or p50 in IECs led to significant reductions in the promoter activity of DRA and its expression. In chromatin immunoprecipitation assays, p65 bound directly to the promoter of DRA, at the regions of -935 to -629 and -375 to -84. Injection of mice with TNF or incubation of crypt-derived enteroids with TNF reduced their expression of DRA messenger RNA and protein. CONCLUSIONS In human IECs and intestinal tissues from mice, we found TNF to activate NF-κB, which reduced expression of the Cl- / HCO3- exchanger DRA (SLC26A3), via direct binding to the promoter of DRA. This pathway is an important therapeutic target for inflammatory bowel disease-associated diarrhea.
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Affiliation(s)
- Anoop Kumar
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Ishita Chatterjee
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Tarunmeet Gujral
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Anas Alakkam
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Hayley Coffing
- Department of Microbiology and Immunology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Arivarasu N Anbazhagan
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Alip Borthakur
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Seema Saksena
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Ravinder K Gill
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois
| | - Waddah A Alrefai
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Pradeep K Dudeja
- Division of Gastroenterology and Hepatology, University of Illinois at Chicago, Chicago, Illinois; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois.
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23
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Liu X, Zhou X, Xu H, He Z, Shi X, Wu S. SLC34A2 Regulates the Proliferation, Migration, and Invasion of Human Osteosarcoma Cells Through PTEN/PI3K/AKT Signaling. DNA Cell Biol 2017; 36:775-780. [PMID: 28777670 DOI: 10.1089/dna.2017.3750] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Osteosarcoma (OS) is a bone malignancy with high incidence. The underlying molecular mechanisms that are associated with the development of OS need further investigation. In this study, we showed that SLC34A2, a member of the solute carrier gene family, was significantly downregulated in OS patients and cell lines. Overexpression of SLC34A2 inhibited the proliferation, migration, and invasion of OS cells. Mechanistically, we found that SLC34A2 interacted with PTEN, and inactivated the PI3K/AKT signaling pathway. Collectively, our results demonstrated that SLC34A2 plays important roles in regulating the cancer cell growth of OS. The downregulation of SLC34A2 in OS patients suggested that it might be a promising target in the diagnosis and therapy of OS.
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Affiliation(s)
- Xiaozhou Liu
- Department of Orthopedics, Jinling Hospital, School of Medicine, Nanjing University , Nanjing China
| | - Xing Zhou
- Department of Orthopedics, Jinling Hospital, School of Medicine, Nanjing University , Nanjing China
| | - Haidong Xu
- Department of Orthopedics, Jinling Hospital, School of Medicine, Nanjing University , Nanjing China
| | - Zhiwei He
- Department of Orthopedics, Jinling Hospital, School of Medicine, Nanjing University , Nanjing China
| | - Xin Shi
- Department of Orthopedics, Jinling Hospital, School of Medicine, Nanjing University , Nanjing China
| | - Sujia Wu
- Department of Orthopedics, Jinling Hospital, School of Medicine, Nanjing University , Nanjing China
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24
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Zhang LJ, Lu R, Song YN, Zhu JY, Xia W, Zhang M, Shao ZY, Huang Y, Zhou Y, Zhang H, Guo L, Zhang M, Zhang H. Knockdown of anion exchanger 2 suppressed the growth of ovarian cancer cells via mTOR/p70S6K1 signaling. Sci Rep 2017; 7:6362. [PMID: 28743911 PMCID: PMC5526859 DOI: 10.1038/s41598-017-06472-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 06/14/2017] [Indexed: 12/16/2022] Open
Abstract
Anion exchanger 2 (AE2, encoded by SLC4A2) is a sodium-independent chloride/bicarbonate transporter and implicated in the regulation of intracellular pH and membrane potential. Previous studies have linked AE2 to the tumorigenesis of various cancers. Here, AE2 was identified as an up-regulated protein in ovarian cancer tissues compared to adjacent non-tumor lesions based on quantitative proteomics analysis. AE2 mRNA was also overexpressed in human ovarian cancer samples, and that AE2 overexpression correlated with the shortened survival time of ovarian cancer patients. Short-hairpin RNA-mediated knockdown of AE2 in A2780 and SK-OV-R3 cells inhibited cell growth and induced cell cycle G1 phase arrest. In nude mice, its stable knockdown inhibited the tumorigenicity of A2780 cells. Gene set enrichment analysis on The Cancer Genome Atlas dataset identified that the cell cycle process and mTOR pathway were correlatively with the AE2 expression. Expression of key regulators of G1/S transition (Cyclin D1 and CDK4), and phosphorylation levels of p70S6K were notably reduced in AE2 knockdown cells. Moreover, experiments with mTOR inhibitor suggested that AE2 may promote cell cycle progression through mTOR/p70S6K1 pathway. Together, our results suggest up-regulated AE2 promotes ovarian cancer tumorigenesis by activating mTOR/p70S6K1 pathway and implicate the potential application of AE2 in cancer therapy.
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Affiliation(s)
- Li-Jun Zhang
- Central Laboratory, Seventh People's Hospital of Shanghai University of TCM, Shanghai, 200137, China
| | - Renquan Lu
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, 200032, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Ya-Nan Song
- Central Laboratory, Seventh People's Hospital of Shanghai University of TCM, Shanghai, 200137, China
| | - Jian-Yong Zhu
- Central Laboratory, Seventh People's Hospital of Shanghai University of TCM, Shanghai, 200137, China
| | - Wei Xia
- Department of Nuclear Medicine, Seventh People's Hospital of Shanghai University of TCM, Shanghai, 200137, China
| | - Miao Zhang
- Central Laboratory, Seventh People's Hospital of Shanghai University of TCM, Shanghai, 200137, China
| | - Zhi-Yi Shao
- Central Laboratory, Seventh People's Hospital of Shanghai University of TCM, Shanghai, 200137, China
| | - Yan Huang
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
- Department of Gynecological Oncology, Fudan University Shanghai Cancer Center, Shanghai, 200032, China
| | - Yuqi Zhou
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
- Department of Gynecological Oncology, Fudan University Shanghai Cancer Center, Shanghai, 200032, China
| | - Hongqin Zhang
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, 200032, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Lin Guo
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, 200032, China.
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
| | - Meiqin Zhang
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
- Department of Gynecological Oncology, Fudan University Shanghai Cancer Center, Shanghai, 200032, China.
| | - Hong Zhang
- Central Laboratory, Seventh People's Hospital of Shanghai University of TCM, Shanghai, 200137, China.
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Shao X, Min X, Xia X, Lin X, Jiang L, Ding R, Jiang Y. [Association of solute-linked carrier family 26 member A3 gene polymorphisms with ulcerative colitis among Chinese patients]. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 2017; 34:255-260. [PMID: 28397232 DOI: 10.3760/cma.j.issn.1003-9406.2017.02.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
OBJECTIVE To assess the association of single nucleotide polymorphisms (SNPs) and haplotypes of solute-linked carrier family 26 member A3 (SLC26A3) gene with ulcerative colitis (UC) among Chinese patients. METHODS For 416 UC patients and 584 controls, 5 SNPs of the SLC26A3 gene (rs17154444, rs7810937, rs7785539, rs2108225 and rs6951457) were determined with a SNaPshot method. Linkage disequilibrium (LD) and haplotype were analyzed for all subjects. RESULTS The G allele and AG+GG genotype of rs2108225 were more prevalent in UC patients compared with the controls (65.14% vs. 58.65%, P=0.030; 87.02% vs. 81.85%, P=0.012, respectively). The C allele and TC+CC genotype of rs17154444 were more prevalent in patients with severe UC than in other patients (14.00% vs. 6.01%, P<0.01; 28.00% vs. 11.48%, all P<0.01). Similar conclusion may also be drawn for C allele and GC+CC genotype of rs7785539 (8.00% vs. 7.38%, P=0.011; 16.00% vs. 13.93%, P=0.017, respectively). The SNPs rs17154444, rs7810937, rs7785539 and rs2108225 were found to be in strong LD. Compared with the controls, the T-A-G-G haplotype was more prevalent in UC patients (62.60% vs. 58.20%, P=0.017), whereas the T-G-G-A haplotype was less common in UC patients (27.40% vs. 31.60%, P=0.041). CONCLUSION Variations of the SLC26A3 rs2108225 may enhance the risk of UC. The rs17154444 and rs7785539 polymorphisms of the SLC26A3 gene are correlated with the severity of UC. The T-A-G-G haplotype formed by rs17154444, rs781093, rs7785539 and rs2108225 of the SLC26A3 gene may increase the risk for UC, whereas the T-G-G-A haplotype may decrease this risk.
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Affiliation(s)
- Xiaoxiao Shao
- Department of Gastroenterology, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China.
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Jedeon K, Loiodice S, Salhi K, Le Normand M, Houari S, Chaloyard J, Berdal A, Babajko S. Androgen Receptor Involvement in Rat Amelogenesis: An Additional Way for Endocrine-Disrupting Chemicals to Affect Enamel Synthesis. Endocrinology 2016; 157:4287-4296. [PMID: 27684650 DOI: 10.1210/en.2016-1342] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Endocrine-disrupting chemicals (EDCs) that interfere with the steroid axis can affect amelogenesis, leading to enamel hypomineralization similar to that of molar incisor hypomineralization, a recently described enamel disease. We investigated the sex steroid receptors that may mediate the effects of EDCs during rat amelogenesis. The expression of androgen receptor (AR), estrogen receptor (ER)-α, and progesterone receptor was dependent on the stage of ameloblast differentiation, whereas ERβ remained undetectable. AR was the only receptor selectively expressed in ameloblasts involved in final enamel mineralization. AR nuclear translocation and induction of androgen-responsive element-containing promoter activity upon T treatment, demonstrated ameloblast responsiveness to androgens. T regulated the expression of genes involved in enamel mineralization such as KLK4, amelotin, SLC26A4, and SLC5A8 but not the expression of genes encoding matrix proteins, which determine enamel thickness. Vinclozolin and to a lesser extent bisphenol A, two antiandrogenic EDCs that cause enamel defects, counteracted the actions of T. In conclusion, we show, for the first time, the following: 1) ameloblasts express AR; 2) the androgen signaling pathway is involved in the enamel mineralization process; and 3) EDCs with antiandrogenic effects inhibit AR activity and preferentially affect amelogenesis in male rats. Their action, through the AR pathway, may specifically and irreversibly affect enamel, potentially leading to the use of dental defects as a biomarker of exposure to environmental pollutants. These results are consistent with the steroid hormones affecting ameloblasts, raising the issue of the hormonal influence on amelogenesis and possible sexual dimorphism in enamel quality.
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Affiliation(s)
- Katia Jedeon
- Centre de Recherche des Cordeliers (K.J., S.L., K.S., M.L.N., S.H., J.C., A.B., S.B.), INSERM Unité Mixte de Recherche en Santé 1138, Université Paris-Descartes, Université Pierre et Marie Curie-Paris, Paris Laboratory of Molecular Oral Pathophysiology, and Unité de Formation et de Recherche d'Odontologie (K.J., S.L., K.S., S.H., J.C., A.B., S.B.), Université Paris-Diderot, F-75006 Paris, France; and Centre de Référence des Maladies Rares de la Face et de la Cavité Buccale (K.J., A.B.), Hôpital Rothschild, Assistance Publique-Hôpitaux de Paris, F-75571 Paris, France
| | - Sophia Loiodice
- Centre de Recherche des Cordeliers (K.J., S.L., K.S., M.L.N., S.H., J.C., A.B., S.B.), INSERM Unité Mixte de Recherche en Santé 1138, Université Paris-Descartes, Université Pierre et Marie Curie-Paris, Paris Laboratory of Molecular Oral Pathophysiology, and Unité de Formation et de Recherche d'Odontologie (K.J., S.L., K.S., S.H., J.C., A.B., S.B.), Université Paris-Diderot, F-75006 Paris, France; and Centre de Référence des Maladies Rares de la Face et de la Cavité Buccale (K.J., A.B.), Hôpital Rothschild, Assistance Publique-Hôpitaux de Paris, F-75571 Paris, France
| | - Khaled Salhi
- Centre de Recherche des Cordeliers (K.J., S.L., K.S., M.L.N., S.H., J.C., A.B., S.B.), INSERM Unité Mixte de Recherche en Santé 1138, Université Paris-Descartes, Université Pierre et Marie Curie-Paris, Paris Laboratory of Molecular Oral Pathophysiology, and Unité de Formation et de Recherche d'Odontologie (K.J., S.L., K.S., S.H., J.C., A.B., S.B.), Université Paris-Diderot, F-75006 Paris, France; and Centre de Référence des Maladies Rares de la Face et de la Cavité Buccale (K.J., A.B.), Hôpital Rothschild, Assistance Publique-Hôpitaux de Paris, F-75571 Paris, France
| | - Manon Le Normand
- Centre de Recherche des Cordeliers (K.J., S.L., K.S., M.L.N., S.H., J.C., A.B., S.B.), INSERM Unité Mixte de Recherche en Santé 1138, Université Paris-Descartes, Université Pierre et Marie Curie-Paris, Paris Laboratory of Molecular Oral Pathophysiology, and Unité de Formation et de Recherche d'Odontologie (K.J., S.L., K.S., S.H., J.C., A.B., S.B.), Université Paris-Diderot, F-75006 Paris, France; and Centre de Référence des Maladies Rares de la Face et de la Cavité Buccale (K.J., A.B.), Hôpital Rothschild, Assistance Publique-Hôpitaux de Paris, F-75571 Paris, France
| | - Sophia Houari
- Centre de Recherche des Cordeliers (K.J., S.L., K.S., M.L.N., S.H., J.C., A.B., S.B.), INSERM Unité Mixte de Recherche en Santé 1138, Université Paris-Descartes, Université Pierre et Marie Curie-Paris, Paris Laboratory of Molecular Oral Pathophysiology, and Unité de Formation et de Recherche d'Odontologie (K.J., S.L., K.S., S.H., J.C., A.B., S.B.), Université Paris-Diderot, F-75006 Paris, France; and Centre de Référence des Maladies Rares de la Face et de la Cavité Buccale (K.J., A.B.), Hôpital Rothschild, Assistance Publique-Hôpitaux de Paris, F-75571 Paris, France
| | - Jessica Chaloyard
- Centre de Recherche des Cordeliers (K.J., S.L., K.S., M.L.N., S.H., J.C., A.B., S.B.), INSERM Unité Mixte de Recherche en Santé 1138, Université Paris-Descartes, Université Pierre et Marie Curie-Paris, Paris Laboratory of Molecular Oral Pathophysiology, and Unité de Formation et de Recherche d'Odontologie (K.J., S.L., K.S., S.H., J.C., A.B., S.B.), Université Paris-Diderot, F-75006 Paris, France; and Centre de Référence des Maladies Rares de la Face et de la Cavité Buccale (K.J., A.B.), Hôpital Rothschild, Assistance Publique-Hôpitaux de Paris, F-75571 Paris, France
| | - Ariane Berdal
- Centre de Recherche des Cordeliers (K.J., S.L., K.S., M.L.N., S.H., J.C., A.B., S.B.), INSERM Unité Mixte de Recherche en Santé 1138, Université Paris-Descartes, Université Pierre et Marie Curie-Paris, Paris Laboratory of Molecular Oral Pathophysiology, and Unité de Formation et de Recherche d'Odontologie (K.J., S.L., K.S., S.H., J.C., A.B., S.B.), Université Paris-Diderot, F-75006 Paris, France; and Centre de Référence des Maladies Rares de la Face et de la Cavité Buccale (K.J., A.B.), Hôpital Rothschild, Assistance Publique-Hôpitaux de Paris, F-75571 Paris, France
| | - Sylvie Babajko
- Centre de Recherche des Cordeliers (K.J., S.L., K.S., M.L.N., S.H., J.C., A.B., S.B.), INSERM Unité Mixte de Recherche en Santé 1138, Université Paris-Descartes, Université Pierre et Marie Curie-Paris, Paris Laboratory of Molecular Oral Pathophysiology, and Unité de Formation et de Recherche d'Odontologie (K.J., S.L., K.S., S.H., J.C., A.B., S.B.), Université Paris-Diderot, F-75006 Paris, France; and Centre de Référence des Maladies Rares de la Face et de la Cavité Buccale (K.J., A.B.), Hôpital Rothschild, Assistance Publique-Hôpitaux de Paris, F-75571 Paris, France
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Hisamoto S, Shimoda S, Harada K, Iwasaka S, Onohara S, Chong Y, Nakamura M, Bekki Y, Yoshizumi T, Ikegami T, Maehara Y, He XS, Gershwin ME, Akashi K. Hydrophobic bile acids suppress expression of AE2 in biliary epithelial cells and induce bile duct inflammation in primary biliary cholangitis. J Autoimmun 2016; 75:150-160. [PMID: 27592379 DOI: 10.1016/j.jaut.2016.08.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 08/22/2016] [Accepted: 08/23/2016] [Indexed: 12/19/2022]
Abstract
Understanding the mechanisms of chronic inflammation in primary biliary cholangitis (PBC) is essential for successful treatment. Earlier work has demonstrated that patients with PBC have reduced expression of the anion exchanger 2 (AE2) on biliary epithelial cells (BEC) and deletion of AE2 gene has led to a PBC-like disorder in mice. To directly address the role of AE2 in preventing PBC pathogenesis, we took advantage of our ability to isolate human BEC and autologous splenic mononuclear cells (SMC). We studied the influence of hydrophobic bile acids, in particular, glycochenodeoxycholic acid (GCDC), on AE2 expression in BEC and the subsequent impact on the phenotypes of BEC and local inflammatory responses. We demonstrate herein that GCDC reduces AE2 expression in BEC through induction of reactive oxygen species (ROS), which enhances senescence of BEC. In addition, a reduction of AE2 levels by either GCDC or another AE2 inhibitor upregulates expression of CD40 and HLA-DR as well as production of IL-6, IL-8 and CXCL10 from BEC in response to toll like receptor ligands, an effect suppressed by inhibition of ROS. Importantly, reduced AE2 expression enhances the migration of autologous splenic mononuclear cells (SMC) towards BEC. In conclusion, our data highlight a key functional role of AE2 in the maintenance of the normal physiology of BEC and the pathogenic consequences of reduced AE2 expression, including abnormal intrinsic characteristics of BEC and their production of signal molecules that lead to the chronic inflammatory responses in small bile ducts.
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Affiliation(s)
- Satomi Hisamoto
- Department of Medicine and Biosystemic Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Shinji Shimoda
- Department of Medicine and Biosystemic Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Kenichi Harada
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
| | - Sho Iwasaka
- Department of Medicine and Biosystemic Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Shinya Onohara
- Department of Medicine and Biosystemic Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Yong Chong
- Department of Medicine and Biosystemic Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Minoru Nakamura
- Clinical Research Center in National Hospital Organization (NHO), Nagasaki Medical Center and Department of Hepatology, Nagasaki University Graduate School of Biomedical Sciences, Omura, Japan.
| | - Yuki Bekki
- Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Tomoharu Yoshizumi
- Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Toru Ikegami
- Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Yoshihiko Maehara
- Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Xiao-Song He
- Division of Rheumatology, Allergy and Clinical Immunology, School of Medicine, University of California at Davis, Davis, CA, USA.
| | - M Eric Gershwin
- Division of Rheumatology, Allergy and Clinical Immunology, School of Medicine, University of California at Davis, Davis, CA, USA.
| | - Koichi Akashi
- Department of Medicine and Biosystemic Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
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Urso K, Charles JF, Shull GE, Aliprantis AO, Balestrieri B. Anion Exchanger 2 Regulates Dectin-1-Dependent Phagocytosis and Killing of Candida albicans. PLoS One 2016; 11:e0158893. [PMID: 27391897 PMCID: PMC4938408 DOI: 10.1371/journal.pone.0158893] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 06/23/2016] [Indexed: 01/17/2023] Open
Abstract
Anion exchanger 2 (Ae2; gene symbol, Slc4a2) is a plasma membrane Cl-/HCO3- exchanger expressed in the gastrointestinal tract, kidney and bone. We have previously shown that Ae2 is required for the function of osteoclasts, bone resorbing cells of the macrophage lineage, to maintain homeostatic cytoplasmic pH and electroneutrality during acid secretion. Macrophages require endosomal acidification for pathogen killing during the process known as phagocytosis. Chloride is thought to be the principal ion responsible for maintaining electroneutrality during organelle acidification, but whether Cl-/HCO3- exchangers such as Ae2 contribute to macrophage function is not known. In this study we investigated the role of Ae2 in primary macrophages during phagocytosis. We find that Ae2 is expressed in macrophages where it regulates intracellular pH and the binding of Zymosan, a fungal cell wall derivative. Surprisingly, the transcription and surface expression of Dectin-1, the major phagocytic receptor for Candida albicans (C. albicans) and Zymosan, is reduced in the absence of Ae2. As a consequence, Zymosan-induced Tnfα expression is also impaired in Ae2-deficient macrophages. Similar to Ae2 deficiency, pharmacological alkalinization of lysosomal pH with bafilomycin A decreases both Dectin-1 mRNA and cell surface expression. Finally, Ae2-deficient macrophages demonstrate defective phagocytosis and killing of the human pathogenic fungus C. albicans. Our results strongly suggest that Ae2 is a critical factor in the innate response to C. albicans. This study represents an important contribution to a better understanding of how Dectin-1 expression and fungal clearance is regulated.
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Affiliation(s)
- Katia Urso
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women’s, Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Julia F. Charles
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women’s, Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Gary E. Shull
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Antonios O. Aliprantis
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women’s, Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Barbara Balestrieri
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women’s, Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Jeff and Penny Vinik Center for Allergic Disease Research, Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Azzabi O, Fetni I, Selmi I, Halioui S, Ben Hariz M, Giuseppe C, Siala N, Maherzi A. SLC26A3 gene mutations in Tunisian patients with congenital chloride diarrhea. Tunis Med 2016; 94:83. [PMID: 27525615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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30
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Lazo-Fernandez Y, Aguilera G, Pham TD, Park AY, Beierwaltes WH, Sutliff RL, Verlander JW, Pacak K, Osunkoya AO, Ellis CL, Kim YH, Shipley GL, Wynne BM, Hoover RS, Sen SK, Plotsky PM, Wall SM. Pendrin localizes to the adrenal medulla and modulates catecholamine release. Am J Physiol Endocrinol Metab 2015; 309:E534-45. [PMID: 26173457 PMCID: PMC4572452 DOI: 10.1152/ajpendo.00035.2015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 07/09/2015] [Indexed: 02/02/2023]
Abstract
Pendrin (Slc26a4) is a Cl(-)/HCO3 (-) exchanger expressed in renal intercalated cells and mediates renal Cl(-) absorption. With pendrin gene ablation, blood pressure and vascular volume fall, which increases plasma renin concentration. However, serum aldosterone does not significantly increase in pendrin-null mice, suggesting that pendrin regulates adrenal zona glomerulosa aldosterone production. Therefore, we examined pendrin expression in the adrenal gland using PCR, immunoblots, and immunohistochemistry. Pendrin protein was detected in adrenal lysates from wild-type but not pendrin-null mice. However, immunohistochemistry and qPCR of microdissected adrenal zones showed that pendrin was expressed in the adrenal medulla, rather than in cortex. Within the adrenal medulla, pendrin localizes to both epinephrine- and norepinephrine-producing chromaffin cells. Therefore, we examined plasma catecholamine concentration and blood pressure in wild-type and pendrin-null mice under basal conditions and then after 5 and 20 min of immobilization stress. Under basal conditions, blood pressure was lower in the mutant than in the wild-type mice, although epinephrine and norepinephrine concentrations were similar. Catecholamine concentration and blood pressure increased markedly in both groups with stress. With 20 min of immobilization stress, epinephrine and norepinephrine concentrations increased more in pendrin-null than in wild-type mice, although stress produced a similar increase in blood pressure in both groups. We conclude that pendrin is expressed in the adrenal medulla, where it blunts stress-induced catecholamine release.
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Affiliation(s)
| | - Greti Aguilera
- Section on Endocrine Physiology, Developmental Endocrinology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Truyen D Pham
- Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Annie Y Park
- Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - William H Beierwaltes
- Hypertension and Vascular Research Division, Henry Ford Hospital and Wayne State School of Medicine, Detroit, Michigan
| | - Roy L Sutliff
- Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; Atlanta Veterans Affairs Hospital, Atlanta, Georgia
| | - Jill W Verlander
- Department of Medicine, University of Florida, Gainesville, Florida
| | - Karel Pacak
- Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Adeboye O Osunkoya
- Department of Pathology, Emory University School of Medicine, Atlanta, Georgia
| | - Carla L Ellis
- Department of Pathology, Emory University School of Medicine, Atlanta, Georgia
| | - Young Hee Kim
- Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Gregory L Shipley
- Department of Integrative Biology and Pharmacology, University of Texas Medical School at Houston, Houston, Texas
| | - Brandi M Wynne
- Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Robert S Hoover
- Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; Atlanta Veterans Affairs Hospital, Atlanta, Georgia; Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Shurjo K Sen
- Cardiovascular Disease Section, and National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Paul M Plotsky
- Department of Psychiatry, Emory University School of Medicine, Atlanta, Georgia; and
| | - Susan M Wall
- Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
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Mokgokong R, Wang S, Taylor CJ, Barrand MA, Hladky SB. Ion transporters in brain endothelial cells that contribute to formation of brain interstitial fluid. Pflugers Arch 2014; 466:887-901. [PMID: 24022703 PMCID: PMC4006130 DOI: 10.1007/s00424-013-1342-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 08/24/2013] [Accepted: 08/24/2013] [Indexed: 02/07/2023]
Abstract
Ions and water transported across the endothelium lining the blood–brain barrier contribute to the fluid secreted into the brain and are important in maintaining appropriate volume and ionic composition of brain interstitial fluid. Changes in this secretion process may occur after stroke. The present study identifies at transcript and protein level ion transporters involved in the movement of key ions and examines how levels of certain of these alter following oxidative stress. Immunohistochemistry provides evidence for Cl−/HCO3− exchanger, AE2, and Na+, HCO3− cotransporters, NBCe1 and NBCn1, on brain microvessels. mRNA analysis by RT-PCR reveals expression of these transporters in cultured rat brain microvascular endothelial cells (both primary and immortalized GPNT cells) and also Na+/H+ exchangers, NHE1 (primary and immortalized) and NHE2 (primary cells only). Knock-down using siRNA in immortalized GPNT cells identifies AE2 as responsible for much of the Cl−/HCO3− exchange following extracellular chloride removal and NHE1 as the transporter that accounts for most of the Na+/H+ exchange following intracellular acidification. Transcript levels of both AE2 and NHE1 are increased following hypoxia/reoxygenation. Further work is now required to determine the localization of the bicarbonate transporters to luminal or abluminal membranes of the endothelial cells as well as to identify and localize additional transport mechanisms that must exist for K+ and Cl−.
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Affiliation(s)
- Ruth Mokgokong
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
| | - Shanshan Wang
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
| | - Caroline J. Taylor
- O’Brien Institute and Department of Surgery, University of Melbourne, St. Vincent’s Hospital, 42 Fitzroy Street, Fitzroy, Melbourne, VIC 3065 Australia
- Faculty of Health Sciences, Australian Catholic University, Melbourne, VIC 3065 Australia
| | - Margery A. Barrand
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
| | - Stephen B. Hladky
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
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Kim KX, Sanneman JD, Kim HM, Harbidge DG, Xu J, Soleimani M, Wangemann P, Marcus DC. Slc26a7 chloride channel activity and localization in mouse Reissner's membrane epithelium. PLoS One 2014; 9:e97191. [PMID: 24810589 PMCID: PMC4014619 DOI: 10.1371/journal.pone.0097191] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 04/16/2014] [Indexed: 11/19/2022] Open
Abstract
Several members of the SLC26 gene family have highly-restricted expression patterns in the auditory and vestibular periphery and mutations in mice of at least two of these (SLC26A4 and SLC26A5) lead to deficits in hearing and/or balance. A previous report pointed to SLC26A7 as a candidate gene important for cochlear function. In the present study, inner ears were assayed by immunostaining for Slc26a7 in neonatal and adult mice. Slc26a7 was detected in the basolateral membrane of Reissner’s membrane epithelial cells but not neighboring cells, with an onset of expression at P5; gene knockout resulted in the absence of protein expression in Reissner’s membrane. Whole-cell patch clamp recordings revealed anion currents and conductances that were elevated for NO3− over Cl− and inhibited by I− and NPPB. Elevated NO3− currents were absent in Slc26a7 knockout mice. There were, however, no major changes to hearing (auditory brainstem response) of knockout mice during early adult life under constitutive and noise exposure conditions. The lack of Slc26a7 protein expression found in the wild-type vestibular labyrinth was consistent with the observation of normal balance. We conclude that SLC26A7 participates in Cl− transport in Reissner’s membrane epithelial cells, but that either other anion pathways, such as ClC-2, possibly substitute satisfactorily under the conditions tested or that Cl− conductance in these cells is not critical to cochlear function. The involvement of SLC26A7 in cellular pH regulation in other epithelial cells leaves open the possibility that SLC26A7 is needed in Reissner’s membrane cells during local perturbations of pH.
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Affiliation(s)
- Kyunghee X. Kim
- Anatomy & Physiology Department, Cellular Biophysics Laboratory, Kansas State University, Manhattan, Kansas, United States of America
| | - Joel D. Sanneman
- Anatomy & Physiology Department, Cell Physiology Laboratory, Kansas State University, Manhattan, Kansas, United States of America
| | - Hyoung-Mi Kim
- Anatomy & Physiology Department, Cell Physiology Laboratory, Kansas State University, Manhattan, Kansas, United States of America
| | - Donald G. Harbidge
- Anatomy & Physiology Department, Cellular Biophysics Laboratory, Kansas State University, Manhattan, Kansas, United States of America
| | - Jie Xu
- Department of Medicine and Center on Genetics of Transport, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Manoocher Soleimani
- Department of Medicine and Center on Genetics of Transport, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Philine Wangemann
- Anatomy & Physiology Department, Cell Physiology Laboratory, Kansas State University, Manhattan, Kansas, United States of America
| | - Daniel C. Marcus
- Anatomy & Physiology Department, Cellular Biophysics Laboratory, Kansas State University, Manhattan, Kansas, United States of America
- * E-mail:
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Deng Q, Zhang H, Xiang R, Zhang Z, Ling F, Zhuo M, Du H, Wang X. Identification of Mamu-DPA1, Mamu-DQA1, and Mamu-DRA alleles in a cohort of Chinese rhesus macaques. Immunogenetics 2013; 65:901-4. [PMID: 24042461 DOI: 10.1007/s00251-013-0736-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 09/06/2013] [Indexed: 11/25/2022]
Abstract
Rhesus macaques have long been used as animal models for various human diseases; the susceptibility and/or resistance to some of these diseases are related to the major histocompatibility complex (MHC). To gain insight into the MHC background and to facilitate the experimental use of Chinese rhesus macaques, Mamu-DPA1, Mamu-DQA1, and Mamu-DRA alleles were investigated in 30 Chinese rhesus macaques by gene cloning and sequencing. A total of 14 Mamu-DPA1, 17 Mamu-DQA1, and 9 Mamu-DRA alleles were identified in this study. Of these alleles, 22 novel sequences have not been documented in earlier studies, including nine Mamu-DPA1, ten Mamu-DQA1, and three Mamu-DRA alleles. Interestingly, like Mafa-DQA1 and Mafa-DPA1, more than two Mamu-DQA1 and Mamu-DPA1 alleles were detected in one animal in this study, which suggested that they might represent gene duplication. If our findings can be validated by other studies, it will further increase the number of known Mamu-DPA1 and Mamu-DQA1 polymorphisms. Our data also indicated significant differences in MHC class II allele distribution among the Chinese rhesus macaques, Vietnamese cynomolgus macaques, and the previously reported rhesus macaques, which were mostly of Indian origin. This information will not only promote the understanding of Chinese rhesus macaque MHC diversity and polymorphism but will also facilitate the use of Chinese rhesus macaques in studies of human disease.
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Affiliation(s)
- Qing Deng
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, People's Republic of China
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Ishimori S, Kaito H, Matsunoshita N, Otsubo H, Hashimoto F, Ninchoji T, Nozu K, Morisada N, Iijima K. SLC26A3 gene analysis in patients with Bartter and Gitelman syndromes and the clinical characteristics of patients with unidentified mutations. Kobe J Med Sci 2013; 59:E36-E43. [PMID: 23756661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We analyzed the SLC26A3 gene in patients with a clinical diagnosis of Bartter and Gitelman syndromes in whom genetic diagnoses could not be determined. We also examined the genetic and clinical characteristics of patients for whom genetic proof could not be obtained. The present study included 10 patients. With regard to genetic characteristics, 1 patient harbored a heterozygous mutation in the SLC12A3 gene (c.2573T>A, p.L858H), which was also reported in a previous report. With regard to clinical characteristics, 3 patients had abnormalities that were identified incidentally during medical examinations and other illnesses and 1 patient had polyhydramnios. One case of nephrocalcinosis was also noted. Eight patients were of below average height. Although we analyzed the SLC26A3 gene in these 10 patients, none were found to have pathological mutations. Investigation of the outcomes of these cases showed that examination findings had normalized and medication was no longer necessary for 3 patients, whereas hypokalemia and metabolic alkalosis were observed in another patient only in the presence of acute disease. We concluded that few patients develop illnesses because of SLC26A3 mutations. Other disease-related genes may also be involved. Although hypokalemia and metabolic alkalosis are clinical characteristics of Bartter and Gitelman syndromes, many other conditions also present such symptoms, and thus, differential diagnosis is of paramount importance.
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Affiliation(s)
- Shingo Ishimori
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
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Abstract
The mammalian Slc4 (Solute carrier 4) family of transporters is a functionally diverse group of 10 multi-spanning membrane proteins that includes three Cl-HCO3 exchangers (AE1-3), five Na(+)-coupled HCO3(-) transporters (NCBTs), and two other unusual members (AE4, BTR1). In this review, we mainly focus on the five mammalian NCBTs-NBCe1, NBCe2, NBCn1, NDCBE, and NBCn2. Each plays a specialized role in maintaining intracellular pH and, by contributing to the movement of HCO3(-) across epithelia, in maintaining whole-body pH and otherwise contributing to epithelial transport. Disruptions involving NCBT genes are linked to blindness, deafness, proximal renal tubular acidosis, mental retardation, and epilepsy. We also review AE1-3, AE4, and BTR1, addressing their relevance to the study of NCBTs. This review draws together recent advances in our understanding of the phylogenetic origins and physiological relevance of NCBTs and their progenitors. Underlying these advances is progress in such diverse disciplines as physiology, molecular biology, genetics, immunocytochemistry, proteomics, and structural biology. This review highlights the key similarities and differences between individual NCBTs and the genes that encode them and also clarifies the sometimes confusing NCBT nomenclature.
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Affiliation(s)
- Mark D Parker
- Dept. of Physiology and Biophysics, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106-4970, USA.
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Liu Y, Wang DK, Jiang DZ, Qin X, Xie ZD, Wang QK, Liu M, Chen LM. Cloning and functional characterization of novel variants and tissue-specific expression of alternative amino and carboxyl termini of products of slc4a10. PLoS One 2013; 8:e55974. [PMID: 23409100 PMCID: PMC3567025 DOI: 10.1371/journal.pone.0055974] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 01/04/2013] [Indexed: 11/18/2022] Open
Abstract
Previous studies have shown that the electroneutral Na+/HCO3− cotransporter NBCn2 (SLC4A10) is predominantly expressed in the central nervous system (CNS). The physiological and pathological significances of NBCn2 have been well recognized. However, little is known about the tissue specificity of expression of different NBCn2 variants. Moreover, little is known about the expression of NBCn2 proteins in systems other than CNS. Here, we identified a set of novel Slc4a10 variants differing from the originally described ones by containing a distinct 5′ untranslated region encoding a new extreme amino-terminus (Nt). Electrophysiology measurements showed that both NBCn2 variants with alternative Nt contain typical electroneutral Na+-coupled HCO3− transport activity in Xenopus oocytes. Luciferase reporter assay showed that Slc4a10 contains two alternative promoters responsible for expression of the two types of NBCn2 with distinct extreme Nt. Western blotting showed that NBCn2 proteins with the original Nt are primarily expressed in CNS, whereas those with the novel Nt are predominantly expressed in the kidney and to a lesser extent in the small intestine. Due to alternative splicing, the known NBCn2 variants contain two types of carboxyl-termini (CT) differing in the optional inclusion of a PDZ-binding motif. cDNA cloning showed that virtually all NBCn2 variants expressed in epithelial tissues contain, but the vast majority of those from the neural tissues lack the PDZ-binding motif. We conclude that alternative transcription and splicing of Slc4a10 products are regulated in a tissue-specific manner. Our findings provide critical insights that will greatly influence the study of the physiology of NBCn2.
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Affiliation(s)
- Ying Liu
- Department of Biophysics and Molecular Physiology, Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science & Technology School of Life Science & Technology, Wuhan, Hubei, China
| | - Deng-Ke Wang
- Department of Biophysics and Molecular Physiology, Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science & Technology School of Life Science & Technology, Wuhan, Hubei, China
| | - De-Zhi Jiang
- Department of Biophysics and Molecular Physiology, Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science & Technology School of Life Science & Technology, Wuhan, Hubei, China
| | - Xue Qin
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Zhang-Dong Xie
- Department of Biophysics and Molecular Physiology, Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science & Technology School of Life Science & Technology, Wuhan, Hubei, China
| | - Qing K. Wang
- Department of Genetics and Developmental Biology, Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science & Technology School of Life Science & Technology, Wuhan, Hubei, China
| | - Mugen Liu
- Department of Genetics and Developmental Biology, Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science & Technology School of Life Science & Technology, Wuhan, Hubei, China
| | - Li-Ming Chen
- Department of Biophysics and Molecular Physiology, Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science & Technology School of Life Science & Technology, Wuhan, Hubei, China
- * E-mail:
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Hilgen G, Huebner AK, Tanimoto N, Sothilingam V, Seide C, Garrido MG, Schmidt KF, Seeliger MW, Löwel S, Weiler R, Hübner CA, Dedek K. Lack of the sodium-driven chloride bicarbonate exchanger NCBE impairs visual function in the mouse retina. PLoS One 2012; 7:e46155. [PMID: 23056253 PMCID: PMC3467262 DOI: 10.1371/journal.pone.0046155] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 08/27/2012] [Indexed: 11/22/2022] Open
Abstract
Regulation of ion and pH homeostasis is essential for normal neuronal function. The sodium-driven chloride bicarbonate exchanger NCBE (Slc4a10), a member of the SLC4 family of bicarbonate transporters, uses the transmembrane gradient of sodium to drive cellular net uptake of bicarbonate and to extrude chloride, thereby modulating both intracellular pH (pH(i)) and chloride concentration ([Cl(-)](i)) in neurons. Here we show that NCBE is strongly expressed in the retina. As GABA(A) receptors conduct both chloride and bicarbonate, we hypothesized that NCBE may be relevant for GABAergic transmission in the retina. Importantly, we found a differential expression of NCBE in bipolar cells: whereas NCBE was expressed on ON and OFF bipolar cell axon terminals, it only localized to dendrites of OFF bipolar cells. On these compartments, NCBE colocalized with the main neuronal chloride extruder KCC2, which renders GABA hyperpolarizing. NCBE was also expressed in starburst amacrine cells, but was absent from neurons known to depolarize in response to GABA, like horizontal cells. Mice lacking NCBE showed decreased visual acuity and contrast sensitivity in behavioral experiments and smaller b-wave amplitudes and longer latencies in electroretinograms. Ganglion cells from NCBE-deficient mice also showed altered temporal response properties. In summary, our data suggest that NCBE may serve to maintain intracellular chloride and bicarbonate concentration in retinal neurons. Consequently, lack of NCBE in the retina may result in changes in pH(i) regulation and chloride-dependent inhibition, leading to altered signal transmission and impaired visual function.
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Affiliation(s)
- Gerrit Hilgen
- Department of Neurobiology, University Oldenburg, Oldenburg, Germany
| | - Antje K. Huebner
- Institute of Human Genetics, University Hospital Jena, Jena, Germany
| | - Naoyuki Tanimoto
- Division of Ocular Neurodegeneration, Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Vithiyanjali Sothilingam
- Division of Ocular Neurodegeneration, Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Christina Seide
- Division of Ocular Neurodegeneration, Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Marina Garcia Garrido
- Division of Ocular Neurodegeneration, Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Karl-Friedrich Schmidt
- Institut für Allgemeine Zoologie und Tierphysiologie, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Mathias W. Seeliger
- Division of Ocular Neurodegeneration, Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Siegrid Löwel
- Institut für Allgemeine Zoologie und Tierphysiologie, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Reto Weiler
- Department of Neurobiology, University Oldenburg, Oldenburg, Germany
| | | | - Karin Dedek
- Department of Neurobiology, University Oldenburg, Oldenburg, Germany
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Jonchère V, Brionne A, Gautron J, Nys Y. Identification of uterine ion transporters for mineralisation precursors of the avian eggshell. BMC Physiol 2012; 12:10. [PMID: 22943410 PMCID: PMC3582589 DOI: 10.1186/1472-6793-12-10] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 08/16/2012] [Indexed: 11/25/2022]
Abstract
BACKGROUND In Gallus gallus, eggshell formation takes place daily in the hen uterus and requires large amounts of the ionic precursors for calcium carbonate (CaCO3). Both elements (Ca2+, HCO3-) are supplied by the blood via trans-epithelial transport. Our aims were to identify genes coding for ion transporters that are upregulated in the uterine portion of the oviduct during eggshell calcification, compared to other tissues and other physiological states, and incorporate these proteins into a general model for mineral transfer across the tubular gland cells during eggshell formation. RESULTS A total of 37 candidate ion transport genes were selected from our database of overexpressed uterine genes associated with eggshell calcification, and by analogy with mammalian transporters. Their uterine expression was compared by qRTPCR in the presence and absence of eggshell formation, and with relative expression levels in magnum (low Ca2+/HCO3- movement) and duodenum (high rates of Ca2+/HCO3- trans-epithelial transfer). We identified overexpression of eleven genes related to calcium movement: the TRPV6 Ca2+ channel (basolateral uptake of Ca2+), 28 kDa calbindin (intracellular Ca2+ buffering), the endoplasmic reticulum type 2 and 3 Ca2+ pumps (ER uptake), and the inositol trisphosphate receptors type 1, 2 and 3 (ER release). Ca2+ movement across the apical membrane likely involves membrane Ca2+ pumps and Ca2+/Na+ exchangers. Our data suggests that Na+ transport involved the SCNN1 channel and the Na+/Ca2+ exchangers SLC8A1, 3 for cell uptake, the Na+/K+ ATPase for cell output. K+ uptake resulted from the Na+/K+ ATPase, and its output from the K+ channels (KCNJ2, 15, 16 and KCNMA1).We propose that the HCO3- is mainly produced from CO2 by the carbonic anhydrase 2 (CA2) and that HCO3- is secreted through the HCO3-/Cl- exchanger SLC26A9. HCO3- synthesis and precipitation with Ca2+ produce two H+. Protons are absorbed via the membrane's Ca2+ pumps ATP2B1, 2 in the apical membrane and the vacuolar (H+)-atpases at the basolateral level. Our model incorporate Cl- ions which are absorbed by the HCO3-/Cl- exchanger SLC26A9 and by Cl- channels (CLCN2, CFTR) and might be extruded by Cl-/H+ exchanger (CLCN5), but also by Na+ K+ 2 Cl- and K+ Cl- cotransporters. CONCLUSIONS Our Gallus gallus uterine model proposes a large list of ion transfer proteins supplying Ca2+ and HCO3- and maintaining cellular ionic homeostasis. This avian model should contribute towards understanding the mechanisms and regulation for ionic precursors of CaCO3, and provide insight in other species where epithelia transport large amount of calcium or bicarbonate.
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Affiliation(s)
| | | | - Joël Gautron
- INRA, UR83 Recherches Avicoles, F-37380, Nouzilly, France
| | - Yves Nys
- INRA, UR83 Recherches Avicoles, F-37380, Nouzilly, France
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Hirata T, Czapar A, Brin LR, Haritonova A, Bondeson DP, Linser PJ, Cabrero P, Dow JAT, Romero MF. Ion and solute transport by Prestin in Drosophila and Anopheles. J Insect Physiol 2012; 58:563-569. [PMID: 22321763 PMCID: PMC3482613 DOI: 10.1016/j.jinsphys.2012.01.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 01/11/2012] [Accepted: 01/14/2012] [Indexed: 05/31/2023]
Abstract
The gut and Malpighian tubules of insects are the primary sites of active solute and water transport for controlling hemolymph and urine composition, pH, and osmolarity. These processes depend on ATPase (pumps), channels and solute carriers (Slc proteins). Maturation of genomic databases enables us to identify the putative molecular players for these processes. Anion transporters of the Slc4 family, AE1 and NDAE1, have been reported as HCO(3)(-) transporters, but are only part of the story. Here we report Dipteran (Drosophila melanogaster (d) and Anopheles gambiae (Ag)) anion exchangers, belonging to the Slc26 family, which are multi-functional anion exchangers. One Drosophila and two Ag homologues of mammalian Slc26a5 (Prestin) and Slc26a6 (aka, PAT1, CFEX) were identified and designated dPrestin, AgPrestinA and AgPrestinB. dPrestin and AgPrestinB show electrogenic anion exchange (Cl(-)/nHCO(3)(-), Cl(-)/SO(4)(2-) and Cl(-)/oxalate(2-)) in an oocyte expression system. Since these transporters are the only Dipteran Slc26 proteins whose transport is similar to mammalian Slc26a6, we submit that Dipteran Prestin are functional and even molecular orthologues of mammalian Slc26a6. OSR1 kinase increases dPrestin ion transport, implying another set of physiological processes controlled by WNK/SPAK signaling in epithelia. All of these mRNAs are highly expressed in the gut and Malpighian tubules. Dipteran Prestin proteins appear suited for central roles in bicarbonate, sulfate and oxalate metabolism including generating the high pH conditions measured in the Dipteran midgut lumen. Finally, we present and discuss Drosophila genetic models that integrate these processes.
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Affiliation(s)
- Taku Hirata
- Physiology & Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
- Mayo Clinic O’Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
| | - Anna Czapar
- Physiology & Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
| | - Lauren R. Brin
- Physiology & Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
- Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
| | - Alyona Haritonova
- Physiology & Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
| | - Daniel P. Bondeson
- Physiology & Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
- Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
- Mayo Clinic O’Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
| | - Paul J. Linser
- University of Florida Whitney Laboratory, 9505 Ocean Shore Blvd., St. Augustine FL, 32086
| | - Pablo Cabrero
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Julian A. T. Dow
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
- Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, KSA
| | - Michael F. Romero
- Physiology & Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
- Mayo Clinic O’Brien Urology Research Center, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
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Linser PJ, Neira Oviedo M, Hirata T, Seron TJ, Smith KE, Piermarini PM, Romero MF. Slc4-like anion transporters of the larval mosquito alimentary canal. J Insect Physiol 2012; 58:551-562. [PMID: 22251674 PMCID: PMC3322255 DOI: 10.1016/j.jinsphys.2012.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 01/02/2012] [Accepted: 01/03/2012] [Indexed: 05/31/2023]
Abstract
Mosquito larvae exhibit luminal pH extremes along the axial length of their alimentary canal that range from very alkaline (pH>10) in the anterior midgut to slightly acid in the hindgut. The principal buffer in the system is thought to be bicarbonate and/or carbonate, because the lumen is known to contain high levels of bicarbonate/carbonate and is surrounded by various epithelial cell types which express a variety of carbonic anhydrases. However, the precise mechanisms responsible for the transport of bicarbonate/carbonate into and out of the lumen are unclear. In the present study, we test the hypothesis that SLC4-like anion transporters play a role in bicarbonate/carbonate accumulation in the larval mosquito alimentary canal. Molecular, physiological and immnuohistochemical characterizations of Slc4-like transporters in the gut of larval mosquitoes (Aedes aegypti and Anopheles gambiae) demonstrate the presence of both a Na(+)-independent chloride/bicarbonate anion exchanger (AE) as well as a Na(+)-dependent anion exchanger (NDAE). Notably, immunolocalization experiments in Malpighian tubules show that the two proteins can be located in the same tissue, but to different cell types. Immunolabeling experiments in the gastric caecae show that the two proteins can be found in the same cells, but on opposite sides (basal vs. apical). In summary, our results indicate that the alimentary canal of larval mosquitoes exhibits robust expression of two SLC4-like transporters in locations that are consistent with a role in the regulation of luminal pH. The precise physiological contributions of each transporter remain to be determined.
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Affiliation(s)
- Paul J Linser
- University of Florida, Whitney Laboratory, St. Augustine, FL 32086, USA.
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Calil-Silveira J, Serrano-Nascimento C, Nunes MT. Iodide treatment acutely increases pendrin (SLC26A4) mRNA expression in the rat thyroid and the PCCl3 thyroid cell line by transcriptional mechanisms. Mol Cell Endocrinol 2012; 350:118-24. [PMID: 22178794 DOI: 10.1016/j.mce.2011.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 12/01/2011] [Accepted: 12/01/2011] [Indexed: 10/14/2022]
Abstract
Iodine is a critical element involved in thyroid hormone synthesis. Its efflux into the follicular lumen is thought to occur, in part, through pendrin at the apical membrane of thyrocytes. This study attempted to investigate whether iodide administration affects SLC26A4 mRNA expression in rat thyroid and in PCCl3 cells. Rats and cells were treated or not with NaI from 30 min up to 48 h. One group was concomitantly treated with sodium perchlorate. SLC26A4 mRNA expression was also investigated in PCCl3 cells treated with actinomycin D prior to NaI treatment. Iodide administration significantly increased SLC26A4 mRNA content in both models. The simultaneous administration of NaI and perchlorate, as well as the treatment of PCCl3 cells with actinomycin D prevented this effect, indicating that intracellular iodide is essential for this event, which appears to be triggered by transcriptional mechanisms. These data show that intracellular iodide rapidly upregulates SLC26A4 mRNA expression.
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Affiliation(s)
- Jamile Calil-Silveira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, 05508-000 São Paulo, SP, Brazil
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Pesce L, Bizhanova A, Caraballo JC, Westphal W, Butti ML, Comellas A, Kopp P. TSH regulates pendrin membrane abundance and enhances iodide efflux in thyroid cells. Endocrinology 2012; 153:512-21. [PMID: 22109890 PMCID: PMC3249672 DOI: 10.1210/en.2011-1548] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Thyroid hormones are essential for normal development and metabolism. Their synthesis requires transport of iodide into thyroid follicles. The mechanisms involving the apical efflux of iodide into the follicular lumen are poorly elucidated. The discovery of mutations in the SLC26A4 gene in patients with Pendred syndrome (congenital deafness, goiter, and defective iodide organification) suggested a possible role for the encoded protein, pendrin, as an apical iodide transporter. We determined whether TSH regulates pendrin abundance at the plasma membrane and whether this influences iodide efflux. Results of immunoblot and immunofluorescence experiments reveal that TSH and forskolin rapidly increase pendrin abundance at the plasma membrane through the protein kinase A pathway in PCCL-3 rat thyroid cells. The increase in pendrin membrane abundance correlates with a decrease in intracellular iodide as determined by measuring intracellular (125)iodide and can be inhibited by specific blocking of pendrin. Elimination of the putative protein kinase A phosphorylation site T717A results in a diminished translocation to the membrane in response to forskolin. These results demonstrate that pendrin translocates to the membrane in response to TSH and suggest that it may have a physiological role in apical iodide transport and thyroid hormone synthesis.
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Affiliation(s)
- Liuska Pesce
- Division of Endocrinology, Metabolism, and Molecular Medicine, Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, Illinois 60611, USA
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Walker NM, Simpson JE, Hoover EE, Brazill JM, Schweinfest CW, Soleimani M, Clarke LL. Functional activity of Pat-1 (Slc26a6) Cl(−)/HCO₃(−) exchange in the lower villus epithelium of murine duodenum. Acta Physiol (Oxf) 2011; 201:21-31. [PMID: 20969732 DOI: 10.1111/j.1748-1716.2010.02210.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS The apical membrane anion exchanger putative anion transporter-1 (Pat-1) is expressed at significant levels in the lower villus epithelium of murine duodenum. However, previous studies of Cl(−)/HCO₃(−) exchange in the lower villus have failed to demonstrate Pat-1 function. Those studies routinely included luminal glucose which induces Na(+) -coupled glucose transport and acidifies the villus epithelium. Since Pat-1 has been proposed to be an electrogenic 1Cl(−)/2HCO₃(−) exchanger, membrane depolarization or cell acidification during glucose transport may obscure Pat-1 activity. Therefore, we investigated the effects of luminal glucose on Cl(−)(IN)/HCO₃(−) (OUT) exchange activity in the lower villus epithelium. METHODS Cl(−)(IN) /HCO (−) (OUT) exchange of villus epithelium in duodenal mucosa from Pat-1 knockout (KO), Slc26a3 [down-regulated in adenoma (Dra)] KO, cystic fibrosis transmembrane conductance regulator (Cftr) KO and wild-type (WT) littermate mice was measured using the pH-sensitive dye 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein. Short-circuit current (I(sc) ) was measured in Ussing chambers. RESULTS During glucose absorption, Cl(−)(IN)/HCO₃(−) (OUT) exchange in the lower villus epithelium was abolished in the Dra KO and unaffected in the Pat-1 KO relative to WT. However, during electroneutral mannose absorption or electrogenic α-D-methyl glucoside absorption, Cl(−)(IN) /HCO₃(−) (OUT) exchange was reduced in both Pat-1 KO and Dra KO villi. Exposure to high [K(+)] abolished Cl(−)(IN) /HCO₃(−) (OUT) exchange in the Dra KO but not the Dra/Cftr double KO epithelium, suggesting that Pat-1 activity is little affected by membrane depolarization except in the presence of Cftr. CONCLUSIONS The metabolic and electrogenic activity of glucose transport obscures Cl(−)(IN) /HCO₃(−) (OUT) exchange activity of Pat-1 in the lower villus. The inhibitory effects of membrane depolarization on Pat-1 Cl(−)(IN) /HCO₃(−) (OUT) exchange may require concurrent membrane association with Cftr.
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Affiliation(s)
- N M Walker
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, 65211, USA
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44
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Wangemann P, Kim HM, Billings S, Nakaya K, Li X, Singh R, Sharlin DS, Forrest D, Marcus DC, Fong P. Developmental delays consistent with cochlear hypothyroidism contribute to failure to develop hearing in mice lacking Slc26a4/pendrin expression. Am J Physiol Renal Physiol 2009; 297:F1435-47. [PMID: 19692489 PMCID: PMC2781347 DOI: 10.1152/ajprenal.00011.2009] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Accepted: 08/13/2009] [Indexed: 02/08/2023] Open
Abstract
Mutations of SLC26A4 cause an enlarged vestibular aqueduct, nonsyndromic deafness, and deafness as part of Pendred syndrome. SLC26A4 encodes pendrin, an anion exchanger located in the cochlea, thyroid, and kidney. The goal of the present study was to determine whether developmental delays, possibly mediated by systemic or local hypothyroidism, contribute to the failure to develop hearing in mice lacking Slc26a4 (Slc26a4(-/-)). We evaluated thyroid function by voltage and pH measurements, by array-assisted gene expression analysis, and by determination of plasma thyroxine levels. Cochlear development was evaluated for signs of hypothyroidism by microscopy, in situ hybridization, and quantitative RT-PCR. No differences in plasma thyroxine levels were found in Slc26a4(-/-) and sex-matched Slc26a4(+/-) littermates between postnatal day 5 (P5) and P90. In adult Slc26a4(-/-) mice, the transepithelial potential and the pH of thyroid follicles were reduced. No differences in the expression of genes that participate in thyroid hormone synthesis or ion transport were observed at P15, when plasma thyroxine levels peaked. Scala media of the cochlea was 10-fold enlarged, bulging into and thereby displacing fibrocytes, which express Dio2 to generate a cochlear thyroid hormone peak at P7. Cochlear development, including tunnel opening, arrival of efferent innervation at outer hair cells, endochondral and intramembraneous ossification, and developmental changes in the expression of Dio2, Dio3, and Tectb were delayed by 1-4 days. These data suggest that pendrin functions as a HCO3- transporter in the thyroid, that Slc26a4(-/-) mice are systemically euthyroid, and that delays in cochlear development, possibly due to local hypothyroidism, lead to the failure to develop hearing.
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Affiliation(s)
- Philine Wangemann
- Anatomy and Physiology Department, Kansas State University, Manhattan, KS 66506, USA.
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45
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Martial S, Guizouarn H, Gabillat N, Pellissier B, Borgese F. Importance of several cysteine residues for the chloride conductance of trout anion exchanger 1 (tAE1). J Cell Physiol 2007; 213:70-8. [PMID: 17520699 DOI: 10.1002/jcp.21093] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this study, we devised a cysteine-focused point mutation analysis of the chloride channel function of trout anion exchanger 1 (tAE1) expressed in X. laevis oocytes. Seven cysteines, belonging to the transmembrane domain of tAE1, were mutated into serines (either individually or in groups) and the effects of these mutations on the chloride conductance of injected oocytes were measured. We showed that three cysteines were essential for the functional expression of tAE1. Namely, mutations C462S, C583S and C588S reduced Cl(-) conductance by 68%, 52% and 83%, respectively, when compared to wild type tAE1. These residual conductances were still inhibited by 0.5 mM niflumic acid. Western blot experiments demonstrated that C462 was involved in protein expression onto the plasma membrane. A mutant devoid of this residue was unable to express onto the plasma membrane, especially if several other cysteines were missing: consequently, the cysteine-less mutant of tAE1 was not functional. C583 and C588 were involved in the channel function of tAE1 as shown by anion substitution experiments proving that selectivity of the mutated pore differs from the wild type one. On the contrary, they were not involved in the Cl(-)/HCO(3)(-) exchange function of tAE1, as demonstrated by intracellular pH measurements. These and several complementary mutations allow us to conclude that a mutant of tAE1 containing the sole C462 can drive a marginal Cl(-) current; however, the minimal configuration necessary to get optimal functional expression of the tAE1 chloride channel is that of a mutant containing unaffected residues C462, C583 and C588.
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Affiliation(s)
- Sonia Martial
- Laboratoire de Physiologie Cellulaire et Moléculaire, UMR 6548, CNRS-Université de Nice, Bâtiment de Sciences Naturelles, Parc Valrose, Nice Cedex 2, France.
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46
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Simpson JE, Schweinfest CW, Shull GE, Gawenis LR, Walker NM, Boyle KT, Soleimani M, Clarke LL. PAT-1 (Slc26a6) is the predominant apical membrane Cl-/HCO3- exchanger in the upper villous epithelium of the murine duodenum. Am J Physiol Gastrointest Liver Physiol 2007; 292:G1079-88. [PMID: 17170027 DOI: 10.1152/ajpgi.00354.2006] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Basal HCO(3)(-) secretion across the duodenum has been shown in several species to principally involve the activity of apical membrane Cl(-)/HCO(3)(-) exchanger(s). To investigate the identity of relevant anion exchanger(s), experiments were performed using wild-type (WT) mice and mice with gene-targeted deletion of the following Cl(-)/HCO(3)(-) exchangers localized to the apical membrane of murine duodenal villi: Slc26a3 [down-regulated in adenoma (DRA)], Slc26a6 [putative anion transporter 1 (PAT-1)], and Slc4a9 [anion exchanger 4 (AE4)]. RT-PCR of the isolated villous epithelium demonstrated PAT-1, DRA, and AE4 mRNA expression. Using the pH-sensitive dye BCECF, anion exchange rates were measured across the apical membrane of epithelial cells in the upper villus of the intact duodenal mucosa. Under basal conditions, Cl(-)/HCO(3)(-) exchange activity was reduced by 65-80% in the PAT-1(-) duodenum, 30-40% in the DRA(-) duodenum, and <5% in the AE4(-) duodenum compared with the WT duodenum. SO(4)(2-)/HCO(3)(-) exchange was eliminated in the PAT-1(-) duodenum but was not affected in the DRA(-) and AE4(-) duodenum relative to the WT duodenum. Intracellular pH (pH(i)) was reduced in the PAT-1(-) villous epithelium but increased to WT levels in the absence of CO(2)/HCO(3)(-) or during methazolamide treatment. Further experiments under physiological conditions indicated active pH(i) compensation in the PAT-1(-) villous epithelium by combined activities of Na(+)/H(+) exchanger 1 and Cl(-)-dependent transport processes at the basolateral membrane. We conclude that 1) PAT-1 is the major contributor to basal Cl(-)/HCO(3)(-) and SO(4)(2-)/HCO(3)(-) exchange across the apical membrane and 2) PAT-1 plays a role in pH(i) regulation in the upper villous epithelium of the murine duodenum.
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Affiliation(s)
- Janet E Simpson
- Department of Biomedical Sciences, University of Missouri, Columbia, MO, USA
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47
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Fraga S, Luo Y, Jose P, Zandi-Nejad K, Mount DB, Soares-da-Silva P. Dopamine D1-like receptor-mediated inhibition of Cl/HCO3- exchanger activity in rat intestinal epithelial IEC-6 cells is regulated by G protein-coupled receptor kinase 6 (GRK 6). Cell Physiol Biochem 2007; 18:347-60. [PMID: 17170521 DOI: 10.1159/000097612] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2006] [Indexed: 01/11/2023] Open
Abstract
The present study investigated the effect of dopamine D1-like receptor stimulation on the Cl-/HCO3- exchange activity in rat intestinal epithelial IEC-6 cells. The Cl-/HCO3- exchange activity was found to be a chloride-dependent, DIDS-sensitive and niflumate-insensitive process. The presence of the SLC26A6 anion exchanger was detected by both RT-PCR and immunoblotting analysis in IEC-6 cells, in which three different small interfering RNAs (siRNAs) targeting SLC26A6 markedly inhibited Cl-/HCO3- exchange. Activation of dopamine D1-like receptors with SKF 38393 inhibited Cl-/HCO3- exchanger activity, this being antagonized by the D1 selective antagonist SKF 83566. However, effects of SKF 38393 were maximal at 5 min of exposure to the agonist and rapidly diminished with no effect at 15 min, suggestive of agonist-induced desensitization of D1-like receptors. Pretreatment of cells with heparin, a non-selective inhibitor of G protein-coupled receptor kinases (GRKs), prevented the observed attenuation of SKF 38393-induced inhibition of Cl-/HCO3- exchange. Overnight pretreatment with anti-GRK6A and anti-GRK6B, but not with anti-GRK4 antibodies, prevented the loss of SKF 38393-mediated effects. Both PKA and PKC signaling pathways participate in SKF 38393-mediated inhibition of Cl-/HCO3- exchange. These findings suggest that SLC26A6 is at least one of the anion exchanger's family members responsible for Cl-/HCO3- exchange in IEC-6 cells. Dopamine D1 receptors in IEC-6 rapidly desensitize to D1-like agonist stimulation and GRK 6, but not GRK 4, appear to be involved in agonist-mediated responsiveness and desensitization.
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MESH Headings
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/analogs & derivatives
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology
- Animals
- Cells, Cultured
- Chloride-Bicarbonate Antiporters/antagonists & inhibitors
- Chloride-Bicarbonate Antiporters/genetics
- Chloride-Bicarbonate Antiporters/metabolism
- Chloride-Bicarbonate Antiporters/physiology
- Dopamine Agonists/pharmacology
- Dopamine Antagonists/pharmacology
- G-Protein-Coupled Receptor Kinase 4
- G-Protein-Coupled Receptor Kinases
- Gene Expression
- Heparin/pharmacology
- Heparin Antagonists/pharmacology
- Immunohistochemistry
- Intestinal Mucosa/drug effects
- Intestinal Mucosa/enzymology
- Intestinal Mucosa/metabolism
- Intestines/chemistry
- Intestines/cytology
- Protein Serine-Threonine Kinases/analysis
- Protein Serine-Threonine Kinases/antagonists & inhibitors
- Protein Serine-Threonine Kinases/metabolism
- RNA, Messenger/analysis
- Rats
- Receptors, Dopamine D1/agonists
- Receptors, Dopamine D1/metabolism
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Affiliation(s)
- Sónia Fraga
- Institute of Pharmacology and Therapeutics, Faculty of Medicine, Porto, Portugal
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48
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Sasaki S. [Hereditary kidney tubular diseases]. Nihon Jinzo Gakkai Shi 2007; Suppl 50th Ann:107-11. [PMID: 17899836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
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49
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Lee YS, Ouyang YB, Giffard RG. Regulation of the rat brain Na+-driven Cl-/HCO3- exchanger involves protein kinase A and a multiprotein signaling complex. FEBS Lett 2006; 580:4865-71. [PMID: 16916513 DOI: 10.1016/j.febslet.2006.07.075] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Accepted: 07/28/2006] [Indexed: 11/23/2022]
Abstract
The Na(+)-driven Cl(-)/HCO(3)(-) exchanger (NCBE) plays an important role in the regulation of intracellular pH (pH(i)). We previously identified two variants of NCBE from rat brain of which the variant with a carboxyterminal PSD-95/Dlg/ZO-1 (PDZ) motif (rb2NCBE) colocalized with the actin cytoskeleton. Increased rb2NCBE activity by PKA inhibition and reduction by forskolin and cAMP agonist suggest PKA regulation of NCBE. Disruption of actin filaments also decreased rb2NCBE activity. EBP50 and FLAG-rb2NCBE were reciprocally co-immunoprecipitated from rb2NCBE transfected cells. It is concluded that NCBE activity is inhibited by PKA and depends on the integrity of the actin cytoskeleton within a multiprotein complex at the plasma membrane.
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Affiliation(s)
- Yong-Sun Lee
- Department of Anesthesia, S272 Stanford University School of Medicine, Stanford, CA 94305-5117, USA
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50
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Hentschke M, Wiemann M, Hentschke S, Kurth I, Hermans-Borgmeyer I, Seidenbecher T, Jentsch TJ, Gal A, Hübner CA. Mice with a targeted disruption of the Cl-/HCO3- exchanger AE3 display a reduced seizure threshold. Mol Cell Biol 2006; 26:182-91. [PMID: 16354689 PMCID: PMC1317631 DOI: 10.1128/mcb.26.1.182-191.2006] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Neuronal activity results in significant pH shifts in neurons, glia, and interstitial space. Several transport mechanisms are involved in the fine-tuning and regulation of extra- and intracellular pH. The sodium-independent electroneutral anion exchangers (AEs) exchange intracellular bicarbonate for extracellular chloride and thereby lower the intracellular pH. Recently, a significant association was found with the variant Ala867Asp of the anion exchanger AE3, which is predominantly expressed in brain and heart, in a large cohort of patients with idiopathic generalized epilepsy. To analyze a possible involvement of AE3 dysfunction in the pathogenesis of seizures, we generated an AE3-knockout mouse model by targeted disruption of Slc4a3. AE3-knockout mice were apparently healthy, and neither displayed gross histological and behavioral abnormalities nor spontaneous seizures or spike wave complexes in electrocorticograms. However, the seizure threshold of AE3-knockout mice exposed to bicuculline, pentylenetetrazole, or pilocarpine was reduced, and seizure-induced mortality was significantly increased compared to wild-type littermates. In the pyramidal cell layer of the hippocampal CA3 region, where AE3 is strongly expressed, disruption of AE3 abolished sodium-independent chloride-bicarbonate exchange. These findings strongly support the hypothesis that AE3 modulates seizure susceptibility and, therefore, are of significance for understanding the role of intracellular pH in epilepsy.
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Affiliation(s)
- Moritz Hentschke
- Department of Human Genetics, UKE-Hamburg, Butenfeld 42, 22529 Hamburg, Germany
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