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Myochin H, Ohshima N, Izumi T, Hisajima T, Chaleckis R, Mori M. Capillary electrophoresis using triple layer modified capillary facilitating salivary ion analyses: Application to search for potential stress markers induced by cold pressure test. J Chromatogr A 2024; 1720:464769. [PMID: 38442499 DOI: 10.1016/j.chroma.2024.464769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 03/07/2024]
Abstract
In this study, we introduce a novel approach for the analysis of salivary ions using capillary electrophoresis (CE) with a triple-layer coated capillary. The capillary is sequentially coated with cationic silylating reagents, poly(vinylsulfonate), and polybrene to form a custom designed surface that effectively inhibits adsorption of protein matrix on the capillary inner wall and allows for reproducible ion analysis. For the CE with capacitively coupled contactless conductivity detection, we used suitable background electrolytes (BGEs) for salivary ion analysis. Anions were separated using a mixture of 2-(N-morpholino)ethanesulfonic acid and l-arginine, and cations were separated using that with 18-crown-6. This setup enabled rapid separation, within 4 min, together with sensitive detection. We quantified nine common anions and five cations typically found in saliva samples using this CE method, both before and after a cold pressure test (CPT, a standard stress test). The CE system demonstrated consistent ion separation across 30 consecutive measurements without requiring capillary replacement. Notably, the salivary ion balance remained predominantly anion-rich, regardless of the CPT. Cold water exposure induced greater variation in the total anion concentration than in the total cation concentration. Further analysis using multiple regression analysis revealed strong relationships between nitrate and nitrite, formate and phosphate, and potassium and nitrate, before and after the CPT. Notably, potassium and nitrate ions exhibited variations in response to stress. These results provided a method for assessing salivary ion composition and insights into the potential of salivary ions as biomarkers for stress.
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Affiliation(s)
- Hironori Myochin
- Department of Chemistry and Life Science, Faculty of Science and Technology, Kochi University, 2-5-1, Akebono-cho, Kochi 780-8520, Japan
| | - Noriyasu Ohshima
- Department of Biochemistry, Graduate School of Medicine, Gunma University, Maebashi, Gunma 371-8511, Japan
| | - Takashi Izumi
- Department of Biochemistry, Graduate School of Medicine, Gunma University, Maebashi, Gunma 371-8511, Japan; Faculty of Health Care, Teikyo Heisei University, 2-51-4, Higashiikebukuro, Toshima-ku, Tokyo 170-8445, Japan
| | - Tatsuya Hisajima
- Faculty of Health Care, Teikyo Heisei University, 2-51-4, Higashiikebukuro, Toshima-ku, Tokyo 170-8445, Japan
| | - Romanas Chaleckis
- Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Masanobu Mori
- Department of Chemistry and Life Science, Faculty of Science and Technology, Kochi University, 2-5-1, Akebono-cho, Kochi 780-8520, Japan.
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Fiais GA, Ferreira DSDB, de Freitas RN, da Silva LGL, Kawaguchi M, Veras ASC, Teixeira GR, Antoniali C, Dornelles RCM, Nakamune ACDMS, Fakhouri WD, Chaves-Neto AH. Assessment of the toxic effects of levetiracetam on biochemical, functional, and redox parameters of salivary glands in male Wistar rats. Toxicology 2023; 496:153615. [PMID: 37572749 DOI: 10.1016/j.tox.2023.153615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 08/14/2023]
Abstract
Levetiracetam (LEV) is an anticonvulsant for epilepsy. The toxic effects of this medication in tissues have been associated with redox state imbalance, which can lead to salivary gland dysfunction. Therefore, the current work investigated the effects of LEV on the biochemical, functional, and redox parameters of the parotid and submandibular glands in rats. For this, male Wistar rats (Rattus norvegicus albinus) were randomly divided into 3 groups (n = 10/group): Control (0.9% saline solution), LEV100 (100 mg/kg), and LEV300 (300 mg/kg). After 21 consecutive days of intragastric gavage treatments, pilocarpine stimulated saliva secretion was collected for salivary biochemical analysis. The extracted salivary glands were utilized for histomorphometry and redox state analyses. Our results showed that LEV300 increased plasma hepatotoxicity markers and reduced salivary amylase activity and the acinar surface area of the parotid gland. Total oxidant capacity and oxidative damage to lipids and proteins were higher in the parotid gland, while total antioxidant capacity and uric acid levels were reduced in the submandibular gland of the LEV100 group compared to Control. On the other hand, total oxidant capacity, oxidative damage to lipids and proteins, total antioxidant capacity, and uric acid levels were lower in both salivary glands of the LEV300 group compared to Control. Superoxide dismutase and glutathione peroxidase activities were lower in the salivary glands of treated animals compared to Control. In conclusion our data suggest that treatment with LEV represents a potentially toxic agent, that contributes to drug-induced salivary gland dysfunction.
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Affiliation(s)
- Gabriela Alice Fiais
- Departmento de Ciências Básicas, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas, SBFis, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil
| | | | - Rayara Nogueira de Freitas
- Departmento de Ciências Básicas, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação em Ciência Odontológica - Saúde Bucal da Criança, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil
| | - Lucas Guilherme Leite da Silva
- Departmento de Ciências Básicas, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil
| | - Marcelo Kawaguchi
- Departmento de Ciências Básicas, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil
| | - Allice Santos Cruz Veras
- Departamento de Educação Física, Universidade Estadual Paulista (Unesp), Presidente Prudente, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas, SBFis, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil
| | - Giovana Rampazzo Teixeira
- Departamento de Educação Física, Universidade Estadual Paulista (Unesp), Presidente Prudente, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas, SBFis, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil
| | - Cristina Antoniali
- Departmento de Ciências Básicas, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas, SBFis, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil
| | - Rita Cássia Menegati Dornelles
- Departmento de Ciências Básicas, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas, SBFis, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil
| | - Ana Cláudia de Melo Stevanato Nakamune
- Departmento de Ciências Básicas, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas, SBFis, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil
| | - Walid D Fakhouri
- Center for Craniofacial Research, Department of Diagnostic and Biomedical Sciences, School of Dentistry, University of Texas Health Science Center at Houston, Houston, USA
| | - Antonio Hernandes Chaves-Neto
- Departmento de Ciências Básicas, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas, SBFis, Universidade Estadual Paulista (Unesp), Faculdade de Odontologia, Araçatuba, São Paulo, Brazil.
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Langhans W, Watts AG, Spector AC. The elusive cephalic phase insulin response: triggers, mechanisms, and functions. Physiol Rev 2023; 103:1423-1485. [PMID: 36422994 PMCID: PMC9942918 DOI: 10.1152/physrev.00025.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 11/04/2022] [Accepted: 11/20/2022] [Indexed: 11/25/2022] Open
Abstract
The cephalic phase insulin response (CPIR) is classically defined as a head receptor-induced early release of insulin during eating that precedes a postabsorptive rise in blood glucose. Here we discuss, first, the various stimuli that elicit the CPIR and the sensory signaling pathways (sensory limb) involved; second, the efferent pathways that control the various endocrine events associated with eating (motor limb); and third, what is known about the central integrative processes linking the sensory and motor limbs. Fourth, in doing so, we identify open questions and problems with respect to the CPIR in general. Specifically, we consider test conditions that allow, or may not allow, the stimulus to reach the potentially relevant taste receptors and to trigger a CPIR. The possible significance of sweetness and palatability as crucial stimulus features and whether conditioning plays a role in the CPIR are also discussed. Moreover, we ponder the utility of the strict classical CPIR definition based on what is known about the effects of vagal motor neuron activation and thereby acetylcholine on the β-cells, together with the difficulties of the accurate assessment of insulin release. Finally, we weigh the evidence of the physiological and clinical relevance of the cephalic contribution to the release of insulin that occurs during and after a meal. These points are critical for the interpretation of the existing data, and they support a sharper focus on the role of head receptors in the overall insulin response to eating rather than relying solely on the classical CPIR definition.
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Affiliation(s)
- Wolfgang Langhans
- Physiology and Behavior Laboratory, ETH Zürich, Schwerzenbach, Switzerland
| | - Alan G Watts
- Department of Biological Sciences, USC Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Alan C Spector
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida
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A Mathematical Model of Salivary Gland Duct Cells. Bull Math Biol 2022; 84:84. [PMID: 35799078 PMCID: PMC9262821 DOI: 10.1007/s11538-022-01041-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 06/14/2022] [Indexed: 11/18/2022]
Abstract
Saliva is produced in two stages in the salivary glands: the secretion of primary saliva by the acinus and the modification of saliva composition to final saliva by the intercalated and striated ducts. In order to understand the saliva modification process, we develop a mathematical model for the salivary gland duct. The model utilises the realistic 3D structure of the duct reconstructed from an image stack of gland tissue. Immunostaining results show that TMEM16A and aquaporin are expressed in the intercalated duct cells and that ENaC is not. Based on this, the model predicts that the intercalated duct does not absorb Na\documentclass[12pt]{minimal}
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\begin{document}$$^-$$\end{document}- like the striated duct but secretes a small amount of water instead. The input to the duct model is the time-dependent primary saliva generated by an acinar cell model. Our duct model produces final saliva output that agrees with the experimental measurements at various stimulation levels. It also shows realistic biological features such as duct cell volume, cellular concentrations and membrane potentials. Simplification of the model by omission of all detailed 3D structures of the duct makes a negligible difference to the final saliva output. This shows that saliva production is not sensitive to structural variation of the duct.
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Duval JF, van Leeuwen HP, Norde W, Town RM. Chemodynamic features of nanoparticles: Application to understanding the dynamic life cycle of SARS-CoV-2 in aerosols and aqueous biointerfacial zones. Adv Colloid Interface Sci 2021; 290:102400. [PMID: 33713994 PMCID: PMC7931671 DOI: 10.1016/j.cis.2021.102400] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/27/2021] [Accepted: 03/01/2021] [Indexed: 12/23/2022]
Abstract
We review concepts involved in describing the chemodynamic features of nanoparticles and apply the framework to gain physicochemical insights into interactions between SARS-CoV-2 virions and airborne particulate matter (PM). Our analysis is highly pertinent given that the World Health Organisation acknowledges that SARS-CoV-2 may be transmitted by respiratory droplets, and the US Center for Disease Control and Prevention recognises that airborne transmission of SARS-CoV-2 can occur. In our theoretical treatment, the virion is assimilated to a core-shell nanoparticle, and contributions of various interaction energies to the virion-PM association (electrostatic, hydrophobic, London-van der Waals, etc.) are generically included. We review the limited available literature on the physicochemical features of the SARS-CoV-2 virion and identify knowledge gaps. Despite the lack of quantitative data, our conceptual framework qualitatively predicts that virion-PM entities are largely able to maintain equilibrium on the timescale of their diffusion towards the host cell surface. Comparison of the relevant mass transport coefficients reveals that virion biointernalization demand by alveolar host cells may be greater than the diffusive supply. Under such conditions both the free and PM-sorbed virions may contribute to the transmitted dose. This result points to the potential for PM to serve as a shuttle for delivery of virions to host cell targets. Thus, our critical review reveals that the chemodynamics of virion-PM interactions may play a crucial role in the transmission of COVID-19, and provides a sound basis for explaining reported correlations between episodes of air pollution and outbreaks of COVID-19.
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Sneyd J, Vera-Sigüenza E, Rugis J, Pages N, Yule DI. Calcium Dynamics and Water Transport in Salivary Acinar Cells. Bull Math Biol 2021; 83:31. [PMID: 33594615 PMCID: PMC8018713 DOI: 10.1007/s11538-020-00841-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/25/2020] [Indexed: 01/07/2023]
Abstract
Saliva is secreted from the acinar cells of the salivary glands, using mechanisms that are similar to other types of water-transporting epithelial cells. Using a combination of theoretical and experimental techniques, over the past 20 years we have continually developed and modified a quantitative model of saliva secretion, and how it is controlled by the dynamics of intracellular calcium. However, over approximately the past 5 years there have been significant developments both in our understanding of the underlying mechanisms and in the way these mechanisms should best be modelled. Here, we review the traditional understanding of how saliva is secreted, and describe how our work has suggested important modifications to this traditional view. We end with a brief description of the most recent data from living animals and discuss how this is now contributing to yet another iteration of model construction and experimental investigation.
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Affiliation(s)
- James Sneyd
- Department of Mathematics, The University of Auckland, Level 2, Building 303, 38 Princes Street, Auckland, New Zealand.
| | | | | | | | - David I Yule
- School of Medicine and Dentistry, University of Rochester Medical Center, 601 Elmwood Ave, Box 711, Rochester, NY, USA
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Salivary biochemical variables in liver transplanted children and young adults. Eur Arch Paediatr Dent 2020; 22:257-263. [PMID: 33135122 DOI: 10.1007/s40368-020-00573-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Accepted: 10/15/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To investigate associations between levels of blood parameters used to monitor liver-transplanted children with their salivary levels, and compare the salivary parameters of transplant recipients with those of healthy controls. METHODS Saliva and blood samples from 30 liver transplanted recipients, mean age 11.7 years and saliva from age and sex matched 27 healthy patients were analyzed using a standard complete blood count test. RESULTS Uric acid and alkaline phosphatase levels correlated significantly between saliva and blood samples in the transplanted subjects. Median salivary sodium level was significantly lower and the median salivary potassium level significantly higher in transplant recipients compared with healthy subjects. No differences were found between the groups in salivary glucose, urea, chloride, total protein, albumin, calcium, phosphorus, uric acid, total bilirubin, alkaline phosphatase, lactate dehydrogenase (LDH), glutamic oxaloacetic transaminase (GOT), triglycerides, cholesterol, iron, transferrin, glutamic pyruvic transaminase (GPT) and gamma-glutamyltranspeptidase (GGT). CONCLUSION Specific correlations of serum and salivary chemistry were found in liver transplant patients. Such information may lead to the development of noninvasive monitoring tools for this population.
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8
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Pedersen SF, Counillon L. The SLC9A-C Mammalian Na +/H + Exchanger Family: Molecules, Mechanisms, and Physiology. Physiol Rev 2019; 99:2015-2113. [PMID: 31507243 DOI: 10.1152/physrev.00028.2018] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Na+/H+ exchangers play pivotal roles in the control of cell and tissue pH by mediating the electroneutral exchange of Na+ and H+ across cellular membranes. They belong to an ancient family of highly evolutionarily conserved proteins, and they play essential physiological roles in all phyla. In this review, we focus on the mammalian Na+/H+ exchangers (NHEs), the solute carrier (SLC) 9 family. This family of electroneutral transporters constitutes three branches: SLC9A, -B, and -C. Within these, each isoform exhibits distinct tissue expression profiles, regulation, and physiological roles. Some of these transporters are highly studied, with hundreds of original articles, and some are still only rudimentarily understood. In this review, we present and discuss the pioneering original work as well as the current state-of-the-art research on mammalian NHEs. We aim to provide the reader with a comprehensive view of core knowledge and recent insights into each family member, from gene organization over protein structure and regulation to physiological and pathophysiological roles. Particular attention is given to the integrated physiology of NHEs in the main organ systems. We provide several novel analyses and useful overviews, and we pinpoint main remaining enigmas, which we hope will inspire novel research on these highly versatile proteins.
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Affiliation(s)
- S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - L Counillon
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
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Bilancio G, Cavallo P, Lombardi C, Guarino E, Cozza V, Giordano F, Palladino G, Cirillo M. Saliva for assessing creatinine, uric acid, and potassium in nephropathic patients. BMC Nephrol 2019; 20:242. [PMID: 31272423 PMCID: PMC6609386 DOI: 10.1186/s12882-019-1437-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 06/24/2019] [Indexed: 12/20/2022] Open
Abstract
Background Lab tests on saliva could be useful because of low invasivity. Previous reports indicated that creatinine, uric acid, and potassium are measurable in saliva. For these analytes the study investigated methodology of saliva tests and correlations between plasma and saliva levels. Methods The study enrolled 15 healthy volunteers for methodological analyses and 42 nephropathic patients for plasma-saliva correlations (35 non-dialysis and 7 dialysis). Saliva was collected by synthetic swap right after venipuncture for blood withdrawal. Blood and saliva, unless otherwise indicated, were collected early in the morning after overnight fast and lab tests were performed in fresh samples by automated biochemistry (standard). Methodological analyses included blind duplicates, different collection mouth sites, day-to-day variability, different collection times, and freezing-thawing effects. Analyses on plasma-saliva correlations included post-dialysis changes. Results For saliva lab tests of all analytes, blind duplicates, samples from different mouth sites or of different days were not significantly different but were significantly correlated (differences ≤14.4%; R ≥ 0.620, P ≤ 0.01). For all analytes, mid-morning saliva had lower levels than but correlated with standard saliva (differences ≥15.8%; R ≥ 0.728, P ≤ 0.01). Frozen-thawed saliva had lower levels than fresh saliva for uric acid only (− 17.2%, P < 0.001). Frozen-thawed saliva correlated with fresh saliva for all analytes (R ≥ 0.818, P ≤ 0.001). Saliva and plasma levels differed but correlated with plasma for creatinine (R = 0.874, P < 0.001), uric acid (R = 0.821, P < 0.001) and potassium (R = 0.767, P < 0.001). Post-dialysis changes in saliva paralleled post-dialysis changes in plasma. Conclusion Saliva levels of creatinine, uric acid, and potassium are measurable and correlated with their plasma levels. Early morning fasting fresh saliva samples are advisable because later collection times or freezing lower the saliva levels of these analytes.
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Affiliation(s)
- Giancarlo Bilancio
- Department "Scuola Medica Salernitana", University of Salerno, Baronissi, SA, Italy.,Nephrology Clinic, University Hospital, Salerno, SA, Italy
| | | | | | - Ermanno Guarino
- Department "Scuola Medica Salernitana", University of Salerno, Baronissi, SA, Italy
| | - Vincenzo Cozza
- Department "Scuola Medica Salernitana", University of Salerno, Baronissi, SA, Italy
| | - Francesco Giordano
- Department "Scuola Medica Salernitana", University of Salerno, Baronissi, SA, Italy
| | | | - Massimo Cirillo
- Department Public Health, University of Naples "Federico II", Via Sergio Pansini, 5, 80131, Naples, Italy.
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Koumangoye R, Omer S, Delpire E. Mistargeting of a truncated Na-K-2Cl cotransporter in epithelial cells. Am J Physiol Cell Physiol 2018; 315:C258-C276. [PMID: 29719172 DOI: 10.1152/ajpcell.00130.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We recently reported the case of a young patient with multisystem failure carrying a de novo mutation in SLC12A2, the gene encoding the Na-K-2Cl cotransporter-1 (NKCC1). Heterologous expression studies in nonepithelial cells failed to demonstrate dominant-negative effects. In this study, we examined expression of the mutant cotransporter in epithelial cells. Using Madin-Darby canine kidney (MDCK) cells grown on glass coverslips, permeabilized support, and Matrigel, we show that the fluorescently tagged mutant cotransporter is expressed in cytoplasm and at the apical membrane and affects epithelium integrity. Expression of the mutant transporter at the apical membrane also results in the mislocalization of some of the wild-type transporter to the apical membrane. This mistargeting is specific to NKCC1 as the Na+-K+-ATPase remains localized on the basolateral membrane. To assess transporter localization in vivo, we created a mouse model using CRISPR/cas9 that reproduces the 11 bp deletion in exon 22 of Slc12a2. Although the mice do not display an overt phenotype, we show that the colon and salivary gland expresses wild-type NKCC1 abundantly at the apical pole, confirming the data obtained in cultured epithelial cells. Enough cotransporter must remain, however, on the basolateral membrane to participate in saliva secretion, as no significant decrease in saliva production was observed in the mutant mice.
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Affiliation(s)
- Rainelli Koumangoye
- Department of Anesthesiology, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Salma Omer
- Department of Anesthesiology, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine , Nashville, Tennessee
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Peña-Münzenmayer G, George AT, Shull GE, Melvin JE, Catalán MA. Ae4 (Slc4a9) is an electroneutral monovalent cation-dependent Cl-/HCO3- exchanger. J Gen Physiol 2017; 147:423-36. [PMID: 27114614 PMCID: PMC4845690 DOI: 10.1085/jgp.201611571] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/05/2016] [Indexed: 12/31/2022] Open
Abstract
Ae4 (Slc4a9) belongs to the Slc4a family of Cl(-)/HCO3 (-) exchangers and Na(+)-HCO3 (-) cotransporters, but its ion transport cycle is poorly understood. In this study, we find that native Ae4 activity in mouse salivary gland acinar cells supports Na(+)-dependent Cl(-)/HCO3 (-) exchange that is comparable with that obtained upon heterologous expression of mouse Ae4 and human AE4 in CHO-K1 cells. Additionally, whole cell recordings and ion concentration measurements demonstrate that Na(+) is transported by Ae4 in the same direction as HCO3 (-) (and opposite to that of Cl(-)) and that ion transport is not associated with changes in membrane potential. We also find that Ae4 can mediate Na(+)-HCO3 (-) cotransport-like activity under Cl(-)-free conditions. However, whole cell recordings show that this apparent Na(+)-HCO3 (-) cotransport activity is in fact electroneutral HCO3 (-)/Na(+)-HCO3 (-) exchange. Although the Ae4 anion exchanger is thought to regulate intracellular Cl(-) concentration in exocrine gland acinar cells, our thermodynamic calculations predict that the intracellular Na(+), Cl(-), and HCO3 (-) concentrations required for Ae4-mediated Cl(-) influx differ markedly from those reported for acinar secretory cells at rest or under sustained stimulation. Given that K(+) ions share many properties with Na(+) ions and reach intracellular concentrations of 140-150 mM (essentially the same as extracellular [Na(+)]), we hypothesize that Ae4 could mediate K(+)-dependent Cl(-)/HCO3 (-) exchange. Indeed, we find that Ae4 mediates Cl(-)/HCO3 (-) exchange activity in the presence of K(+) as well as Cs(+), Li(+), and Rb(+) In summary, our results strongly suggest that Ae4 is an electroneutral Cl(-)/nonselective cation-HCO3 (-) exchanger. We postulate that the physiological role of Ae4 in secretory cells is to promote Cl(-) influx in exchange for K(+)(Na(+)) and HCO3 (-) ions.
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Affiliation(s)
- Gaspar Peña-Münzenmayer
- Secretory Mechanisms and Dysfunction Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892
| | - Alvin T George
- Secretory Mechanisms and Dysfunction Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892
| | - Gary E Shull
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - James E Melvin
- Secretory Mechanisms and Dysfunction Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892
| | - Marcelo A Catalán
- Secretory Mechanisms and Dysfunction Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892
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Bicarbonate in cystic fibrosis. J Cyst Fibros 2017; 16:653-662. [PMID: 28732801 DOI: 10.1016/j.jcf.2017.06.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/22/2017] [Accepted: 06/22/2017] [Indexed: 11/20/2022]
Abstract
BACKGROUND Cystic fibrosis (CF, mucoviscidosis) is caused by mutations in the gene encoding CF transmembrane conductance regulator (CFTR), which is a chloride and bicarbonate channel necessary for fluid secretion and extracellular alkalization. For a long time, research concentrated on abnormal Cl- and Na+ transport, but neglected bicarbonate as a crucial factor in CF. METHODS The present short review reports early findings as well as recent insights into the role of CFTR for bicarbonate transport and its defects in CF. RESULTS The available data indicate impaired bicarbonate transport not only in pancreas, intestine, airways, and reproductive organs, but also in salivary glands, sweat duct and renal tubular epithelial cells. Defective bicarbonate transport is closely related to the impaired mucus properties and mucus blocking in secretory organs of CF patients, causing the life threatening lung disease. CONCLUSIONS Apart from the devastating lung disease, abrogated bicarbonate transport also leads to many other organ dysfunctions, which are outlined in the present review.
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Fong S, Chiorini JA, Sneyd J, Suresh V. Computational modeling of epithelial fluid and ion transport in the parotid duct after transfection of human aquaporin-1. Am J Physiol Gastrointest Liver Physiol 2017; 312:G153-G163. [PMID: 27932503 PMCID: PMC5341129 DOI: 10.1152/ajpgi.00374.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 12/05/2016] [Accepted: 12/05/2016] [Indexed: 01/31/2023]
Abstract
UNLABELLED Previous studies have shown that localized delivery of the aquaporin-1 (AQP1) gene to the parotid duct can restore saliva flow in minipigs following irradiation-induced salivary hypofunction. The resulting flow rate and electrochemistry of secreted saliva contradicts current understanding of ductal fluid transport. We hypothesized that changes in expression of ion transport proteins have occurred following AQP1 transfection. We use a mathematical model of ion and fluid transport across the parotid duct epithelial cells to predict the expression profile of ion transporters that are consistent with the experimental measurements of saliva composition and secretion rates. Using a baseline set of parameters, the model reproduces the data for the irradiated, non-AQP1-transfected case. We propose three scenarios which may have occurred after transfection, which differ in the location of the AQP1 gene. The first scenario places AQP1 within nonsecretory cells, and requires that epithelial sodium channel (ENaC) expression is greatly reduced (1.3% of baseline), and ductal bicarbonate concentration is increased from 40.6 to 137.0 mM, to drive water secretion into the duct. The second scenario introduces the AQP1 gene into all ductal cells. The final scenario has AQP1 primarily in the proximal duct cells which secrete water under baseline conditions. We find the change in the remaining cells includes a 95.8% reduction in ENaC expression, enabling us to reproduce all experimental ionic concentrations within 9 mM. These findings provide a mechanistic basis for the observations and will guide the further development of gene transfer therapy for salivary hypofunction. NEW & NOTEWORTHY Following transfection of aquaporin into the parotid ducts of minipigs with salivary hypofunction, the resulting increase in salivary flow rates contradicts current understanding of ductal fluid transport. We show that the change in saliva electrochemistry and flow rate can be explained by changes in expression of ion transporters in the ductal cell membranes, using a mathematical model replicating a single parotid duct.
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Affiliation(s)
- Shelley Fong
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand;
| | - John A Chiorini
- 2Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland;
| | - James Sneyd
- 3Department of Mathematics, University of Auckland, Auckland, New Zealand; and
| | - Vinod Suresh
- 1Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; ,4Department of Engineering Science, University of Auckland, Auckland, New Zealand
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Gluck C, Min S, Oyelakin A, Smalley K, Sinha S, Romano RA. RNA-seq based transcriptomic map reveals new insights into mouse salivary gland development and maturation. BMC Genomics 2016; 17:923. [PMID: 27852218 PMCID: PMC5112738 DOI: 10.1186/s12864-016-3228-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 10/29/2016] [Indexed: 11/16/2022] Open
Abstract
Background Mouse models have served a valuable role in deciphering various facets of Salivary Gland (SG) biology, from normal developmental programs to diseased states. To facilitate such studies, gene expression profiling maps have been generated for various stages of SG organogenesis. However these prior studies fall short of capturing the transcriptional complexity due to the limited scope of gene-centric microarray-based technology. Compared to microarray, RNA-sequencing (RNA-seq) offers unbiased detection of novel transcripts, broader dynamic range and high specificity and sensitivity for detection of genes, transcripts, and differential gene expression. Although RNA-seq data, particularly under the auspices of the ENCODE project, have covered a large number of biological specimens, studies on the SG have been lacking. Results To better appreciate the wide spectrum of gene expression profiles, we isolated RNA from mouse submandibular salivary glands at different embryonic and adult stages. In parallel, we processed RNA-seq data for 24 organs and tissues obtained from the mouse ENCODE consortium and calculated the average gene expression values. To identify molecular players and pathways likely to be relevant for SG biology, we performed functional gene enrichment analysis, network construction and hierarchal clustering of the RNA-seq datasets obtained from different stages of SG development and maturation, and other mouse organs and tissues. Our bioinformatics-based data analysis not only reaffirmed known modulators of SG morphogenesis but revealed novel transcription factors and signaling pathways unique to mouse SG biology and function. Finally we demonstrated that the unique SG gene signature obtained from our mouse studies is also well conserved and can demarcate features of the human SG transcriptome that is different from other tissues. Conclusions Our RNA-seq based Atlas has revealed a high-resolution cartographic view of the dynamic transcriptomic landscape of the mouse SG at various stages. These RNA-seq datasets will complement pre-existing microarray based datasets, including the Salivary Gland Molecular Anatomy Project by offering a broader systems-biology based perspective rather than the classical gene-centric view. Ultimately such resources will be valuable in providing a useful toolkit to better understand how the diverse cell population of the SG are organized and controlled during development and differentiation. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3228-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Christian Gluck
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Sangwon Min
- Department of Oral Biology, School of Dental Medicine, State University of New York at Buffalo, 3435 Main Street, Buffalo, NY, 14214, USA
| | - Akinsola Oyelakin
- Department of Oral Biology, School of Dental Medicine, State University of New York at Buffalo, 3435 Main Street, Buffalo, NY, 14214, USA
| | - Kirsten Smalley
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Satrajit Sinha
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA.
| | - Rose-Anne Romano
- Department of Oral Biology, School of Dental Medicine, State University of New York at Buffalo, 3435 Main Street, Buffalo, NY, 14214, USA.
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Varga G, Kerémi B, Bori E, Földes A. Function and repair of dental enamel - Potential role of epithelial transport processes of ameloblasts. Pancreatology 2015; 15:S55-60. [PMID: 25747281 DOI: 10.1016/j.pan.2015.01.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 01/28/2015] [Indexed: 12/11/2022]
Abstract
The hardest mammalian tissue, dental enamel is produced by ameloblasts, which are electrolyte-transporting epithelial cells. Although the end product is very different, they show many similarities to transporting epithelia of the pancreas, salivary glands and kidney. Enamel is produced in a multi-step epithelial secretory process that features biomineralization which is an interplay of secreted ameloblast specific proteins and the time-specific transport of minerals, protons and bicarbonate. First, "secretory" ameloblasts form the entire thickness of the enamel layer, but with low mineral content. Then they differentiate into "maturation" ameloblasts, which remove organic matrix from the enamel and in turn further build up hydroxyapatite crystals. The protons generated by hydroxyapatite formation need to be buffered, otherwise enamel will not attain full mineralization. Buffering requires a tight pH regulation and secretion of bicarbonate by ameloblasts. The whole process has been the focus of many immunohistochemical and gene knock-out studies, but, perhaps surprisingly, no functional data existed for mineral ion transport by ameloblasts. However, recent studies including ours provided a better insight for molecular mechanism of mineral formation. The secretory regulation is not completely known as yet, but its significance is crucial. Impairing regulation retards or prevents completion of enamel mineralization and results in the development of hypomineralized enamel that easily erodes after dental eruption. Factors that impair this function are fluoride and disruption of pH regulators. Revealing these factors may eventually lead to the treatment of enamel hypomineralization related to genetic or environmentally induced malformation.
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Affiliation(s)
- Gábor Varga
- Department of Oral Biology, Semmelweis University, Budapest, Hungary.
| | - Beáta Kerémi
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Erzsébet Bori
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Anna Földes
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
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Multiscale modelling of saliva secretion. Math Biosci 2014; 257:69-79. [PMID: 25014770 DOI: 10.1016/j.mbs.2014.06.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 06/18/2014] [Accepted: 06/26/2014] [Indexed: 01/28/2023]
Abstract
We review a multiscale model of saliva secretion, describing in brief how the model is constructed and what we have so far learned from it. The model begins at the level of inositol trisphosphate receptors (IPR), and proceeds through the cellular level (with a model of acinar cell calcium dynamics) to the multicellular level (with a model of the acinus), finally to a model of a saliva production unit that includes an acinus and associated duct. The model at the level of the entire salivary gland is not yet completed. Particular results from the model so far include (i) the importance of modal behaviour of IPR, (ii) the relative unimportance of Ca(2+) oscillation frequency as a controller of saliva secretion, (iii) the need for the periodic Ca(2+) waves to be as fast as possible in order to maximise water transport, (iv) the presence of functional K(+) channels in the apical membrane increases saliva secretion, (v) the relative unimportance of acinar spatial structure for isotonic water transport, (vi) the prediction that duct cells are highly depolarised, (vii) the prediction that the secondary saliva takes at least 1mm (from the acinus) to reach ionic equilibrium. We end with a brief discussion of future directions for the model, both in construction and in the study of scientific questions.
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