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Song EAC, Chung SH, Kim JH. Molecular mechanisms of saliva secretion and hyposecretion. Eur J Oral Sci 2024; 132:e12969. [PMID: 38192116 DOI: 10.1111/eos.12969] [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: 09/11/2023] [Accepted: 12/16/2023] [Indexed: 01/10/2024]
Abstract
The exocrine salivary gland secretes saliva, a fundamental body component to maintain oral homeostasis. Saliva is composed of water, ions, and proteins such as amylase, mucins, and immunoglobulins that play essential roles in the digestion of food, lubrication, and prevention of dental caries and periodontitis. An increasing number of people experience saliva hyposecretion due to aging, medications, Sjögren's syndrome, and radiation therapy for head and neck cancer. However, current treatments are mostly limited to temporary symptomatic relief. This review explores the molecular mechanisms underlying saliva secretion and hyposecretion to provide insight into putative therapeutic targets for treatment. Proteins implicated in saliva secretion pathways, including Ca2+ -signaling proteins, aquaporins, soluble N-ethylmaleimide-sensitive factor attachment protein receptors, and tight junctions, are aberrantly expressed and localized in patients with saliva hyposecretion, such as Sjögren's syndrome. Analysis of studies on the mechanisms of saliva secretion and hyposecretion suggests that crosstalk between fluid and protein secretory pathways via Ca2+ /protein kinase C and cAMP/protein kinase A regulates saliva secretion. Impaired crosstalk between the two secretory pathways may contribute to saliva hyposecretion. Future research into the detailed regulatory mechanisms of saliva secretion and hyposecretion may provide information to define novel targets and generate therapeutic strategies for saliva hyposecretion.
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Affiliation(s)
- Eun-Ah Christine Song
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Sul-Hee Chung
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Jeong Hee Kim
- Department of Oral Biochemistry and Molecular Biology, School of Dentistry, Kyung Hee University, Seoul, Republic of Korea
- Department of KHU-KIST Converging Science and Technology, Graduate School, Kyung Hee University, Seoul, Republic of Korea
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2
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Vazão AR, Claudino L, Pimpinato PP, Sampaio LV, Fiais GA, de Freitas RN, Justo MP, Brito VGB, Oliveira SHP, Lima RR, Cintra LTÂ, Chaves-Neto AH. Experimental apical periodontitis alters salivary biochemical composition and induces local redox state disturbances in the salivary glands of male rats. Clin Oral Investig 2024; 28:154. [PMID: 38366095 DOI: 10.1007/s00784-024-05540-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/31/2024] [Indexed: 02/18/2024]
Abstract
OBJECTIVES The objective was to evaluate the effects of experimental apical periodontitis on the inflammatory, functional, biochemical, and redox parameters of the parotid and submandibular glands in rats. MATERIALS AND METHODS Twenty 12-week-old male Wistar rats were randomly divided into two groups (n = 10): a control group and apical periodontitis group. After 28 days, the saliva was collected for salivary flow rate and biochemistry composition. Both glands were sampled for quantification of the tumor necrosis factor-alpha (TNF-α) and biochemical analyses of redox state. RESULTS TNF-α concentrations were higher in both salivary glands adjacent to the periapical lesions in animals with apical periodontitis and also compared to the control group. The apical periodontitis group increased the salivary amylase, chloride, potassium, calcium, and phosphate. The total oxidant capacity increased in the parotid gland adjacent to the periapical lesions in the same rat and compared to the control group. Conversely, the total antioxidant capacity of the parotid glands on both sides in the apical periodontitis group was lower than that in the control group. Furthermore, glutathione peroxidase activity increased in the submandibular gland adjacent to the apical periodontitis group compared to the control group. CONCLUSIONS Experimental apical periodontitis alters salivary biochemical composition, in addition to increasing inflammatory marker and inducing local disturbances in the redox state in the parotid and submandibular glands of male rats. CLINICAL RELEVANCE Apical periodontitis could exacerbate the decline in oral health by triggering dysfunction in the salivary glands.
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Affiliation(s)
- Arieli Raymundo Vazão
- Programa de Pós-Graduação em Ciências, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
- Department of Basic Sciences, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
| | - Lívia Claudino
- Department of Basic Sciences, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
| | - Pedro Penati Pimpinato
- Department of Basic Sciences, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
| | - Larissa Victorino Sampaio
- Department of Basic Sciences, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas-SBFis, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
| | - Gabriela Alice Fiais
- Department of Basic Sciences, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas-SBFis, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
| | - Rayara Nogueira de Freitas
- Programa de Pós-Graduação em Ciências, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
- Department of Basic Sciences, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
| | - Mariana Pagliusi Justo
- Programa de Pós-Graduação em Ciências, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
- Department of Preventive and Restorative Dentistry, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
| | - Victor Gustavo Balera Brito
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas-SBFis, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
| | - Sandra Helena Penha Oliveira
- Department of Basic Sciences, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas-SBFis, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
| | - Rafael Rodrigues Lima
- Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará (UFPA), Belém, Pará, Brazil
| | - Luciano Tavares Ângelo Cintra
- Programa de Pós-Graduação em Ciências, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
- Department of Preventive and Restorative Dentistry, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil
| | - Antonio Hernandes Chaves-Neto
- Programa de Pós-Graduação em Ciências, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
- Department of Basic Sciences, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas-SBFis, School of Dentistry of Araçatuba-UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
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3
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Al Habobe H, Haverkort EB, Nazmi K, Van Splunter AP, Pieters RHH, Bikker FJ. The impact of saliva collection methods on measured salivary biomarker levels. Clin Chim Acta 2024; 552:117628. [PMID: 37931731 DOI: 10.1016/j.cca.2023.117628] [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: 07/15/2023] [Revised: 11/01/2023] [Accepted: 11/01/2023] [Indexed: 11/08/2023]
Abstract
Saliva diagnostics have become increasingly popular due to their non-invasive nature and patient-friendly collection process. Various collection methods are available, yet these are not always well standardized for either quantitative or qualitative analysis. In line, the objective of this study was to evaluate if measured levels of various biomarkers in the saliva of healthy individuals were affected by three distinct saliva collection methods: 1) unstimulated saliva, 2) chew stimulated saliva, and 3) oral rinse. Saliva samples from 30 healthy individuals were obtained by the three collection methods. Then, the levels of various salivary biomarkers such as proteins and ions were determined. It was found that levels of various biomarkers obtained from unstimulated saliva were comparable to those in chew stimulated saliva. The levels of potassium, sodium, and amylase activity differed significantly among the three collection methods. Levels of all biomarkers measured using the oral rinse method significantly differed from those obtained from unstimulated and chew-stimulated saliva. In conclusion, both unstimulated and chew-stimulated saliva provided comparable levels for a diverse group of biomarkers. However, the results obtained from the oral rinse method significantly differed from those of unstimulated and chew-stimulated saliva, due to the diluted nature of the saliva extract.
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Affiliation(s)
- H Al Habobe
- Research Group Innovative Testing in Life Sciences and Chemistry, Research Centre for Healthy and Sustainable Living, University of Applied Sciences Utrecht, The Netherlands; Institute for Risk Assessment Sciences, Faculty of Veterinary Medicines, Utrecht University, The Netherlands; Dept of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
| | - E B Haverkort
- Research Group Innovations in Preventive Care, Utrecht University of Applied Sciences, The Netherlands
| | - K Nazmi
- Dept of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
| | - A P Van Splunter
- Dept of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
| | - R H H Pieters
- Research Group Innovative Testing in Life Sciences and Chemistry, Research Centre for Healthy and Sustainable Living, University of Applied Sciences Utrecht, The Netherlands; Institute for Risk Assessment Sciences, Faculty of Veterinary Medicines, Utrecht University, The Netherlands
| | - F J Bikker
- Dept of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
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Calamita G, Delporte C. Insights into the Function of Aquaporins in Gastrointestinal Fluid Absorption and Secretion in Health and Disease. Cells 2023; 12:2170. [PMID: 37681902 PMCID: PMC10486417 DOI: 10.3390/cells12172170] [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: 07/01/2023] [Revised: 08/16/2023] [Accepted: 08/17/2023] [Indexed: 09/09/2023] Open
Abstract
Aquaporins (AQPs), transmembrane proteins permeable to water, are involved in gastrointestinal secretion. The secretory products of the glands are delivered either to some organ cavities for exocrine glands or to the bloodstream for endocrine glands. The main secretory glands being part of the gastrointestinal system are salivary glands, gastric glands, duodenal Brunner's gland, liver, bile ducts, gallbladder, intestinal goblet cells, exocrine and endocrine pancreas. Due to their expression in gastrointestinal exocrine and endocrine glands, AQPs fulfill important roles in the secretion of various fluids involved in food handling. This review summarizes the contribution of AQPs in physiological and pathophysiological stages related to gastrointestinal secretion.
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Affiliation(s)
- Giuseppe Calamita
- Department of Biosciences, Biotechnologies and Environment, University of Bari Aldo Moro, 70125 Bari, Italy;
| | - Christine Delporte
- Laboratory of Pathophysiological and Nutritional Biochemistry, Faculty of Medicine, Université Libre de Bruxelles, 1070 Brussels, Belgium
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5
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Calamita G, Delporte C. Aquaporins in Glandular Secretion. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1398:225-249. [PMID: 36717498 DOI: 10.1007/978-981-19-7415-1_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Exocrine and endocrine glands deliver their secretory product, respectively, at the surface of the target organs or within the bloodstream. The release of their products has been shown to rely on secretory mechanisms often involving aquaporins (AQPs). This chapter will provide insight into the role of AQPs in secretory glands located within the gastrointestinal tract, including salivary glands, gastric glands, duodenal Brunner's glands, liver, gallbladder, intestinal goblets cells, and pancreas, as well and in other parts of the body, including airway submucosal glands, lacrimal glands, mammary glands, and eccrine sweat glands. The involvement of AQPs in both physiological and pathophysiological conditions will also be highlighted.
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Affiliation(s)
- Giuseppe Calamita
- Department of Biosciences, Biotechnologies and Environment, University of Bari "Aldo Moro", Bari, Italy
| | - Christine Delporte
- Laboratory of Pathophysiological and Nutritional Biochemistry, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
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6
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Cypriano ML, Dos Santos Ramos GHA, de Oliveira ACF, Dos Santos DR, Fiais GA, de Oliveira AP, Antoniali C, Dornelles RCM, de Melo Stevanato Nakamune AC, Chaves-Neto AH. Effect of testosterone replacement therapy and mate tea (Ilex paraguariensis) on biochemical, functional and redox parameters of saliva in orchiectomized rats. Arch Oral Biol 2021; 132:105289. [PMID: 34695671 DOI: 10.1016/j.archoralbio.2021.105289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 10/08/2021] [Accepted: 10/12/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Evaluate the effects of testosterone replacement therapy (TRT) and mate tea (MT) [Ilex paraguariensis] on biochemical, functional, and redox parameters of saliva in orchiectomized rats (ORX) DESIGN: Sixty young adult male Wistar rats (3 months old) were either castrated bilaterally or underwent fictitious surgery (SHAM) and were distributed into 5 groups: SHAM, ORX, TU (castrated rats that received a single intramuscular injection of testosterone undecanoate 100 mg/kg), MT (castrated rats that received MT 20 mg/kg, via intragastric gavage, daily), and TU + MT. All treatments started 4 weeks after castration (4 months old) and lasted 4 weeks (5 months old). At the end of treatment, pilocarpine-induced salivary secretion was collected to analyze salivary flow rate (SFR) and biochemistry composition through determination of total protein (TP), amylase (AMY), electrolyte, and biomarkers of oxidative stress. RESULTS ORX increased SFR, salivary buffering capacity, calcium, phosphate, chloride, total antioxidant capacity, thiobarbituric acid reactive substances (TBARs), and carbonyl protein, reduced TP and AMY activity, and did not change pH, sodium, and potassium compared to SHAM. TU and TU+MT restored all salivary parameters to values of SHAM, while only TBARs and AMY returned to SHAM levels in the MT group. CONCLUSIONS TRT with long-acting TU restored the biochemical, functional, and redox parameters of saliva in orchiectomized rats. Although MT did not have a TRT-like effect on salivary gland function, the more effective reduction in lipid oxidative damage in the MT and TU + MT groups could be considered as adjuvant to alleviate the salivary oxidative stress induced by orchiectomy.
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Affiliation(s)
- Matheus Lima Cypriano
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | | | | | - Damáris Raissa Dos Santos
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Gabriela Alice Fiais
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Arthur Passos de Oliveira
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Cristina Antoniali
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Rita Cássia Menegati Dornelles
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Ana Cláudia de Melo Stevanato Nakamune
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Antonio Hernandes Chaves-Neto
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil.
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7
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Takano T, Wahl AM, Huang KT, Narita T, Rugis J, Sneyd J, Yule DI. Highly localized intracellular Ca 2+ signals promote optimal salivary gland fluid secretion. eLife 2021; 10:66170. [PMID: 34240705 PMCID: PMC8352588 DOI: 10.7554/elife.66170] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 07/08/2021] [Indexed: 11/23/2022] Open
Abstract
Salivary fluid secretion involves an intricate choreography of membrane transporters to result in the trans-epithelial movement of NaCl and water into the acinus lumen. Current models are largely based on experimental observations in enzymatically isolated cells where the Ca2+ signal invariably propagates globally and thus appears ideally suited to activate spatially separated Cl and K channels, present on the apical and basolateral plasma membrane, respectively. We monitored Ca2+ signals and salivary secretion in live mice expressing GCamp6F, following stimulation of the nerves innervating the submandibular gland. Consistent with in vitro studies, Ca2+ signals were initiated in the apical endoplasmic reticulum. In marked contrast to in vitro data, highly localized trains of Ca2+ transients that failed to fully propagate from the apical region were observed. Following stimuli optimum for secretion, large apical-basal gradients were elicited. A new mathematical model, incorporating these data was constructed to probe how salivary secretion can be optimally stimulated by apical Ca2+ signals.
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Affiliation(s)
- Takahiro Takano
- Department of Pharmacology and Physiology, University of Rochester, Rochester, United States
| | - Amanda M Wahl
- Department of Pharmacology and Physiology, University of Rochester, Rochester, United States
| | - Kai-Ting Huang
- Department of Pharmacology and Physiology, University of Rochester, Rochester, United States
| | - Takanori Narita
- Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Fujisawa, Japan
| | - John Rugis
- Department of Mathematics, University of Auckland, Auckland, New Zealand
| | - James Sneyd
- Department of Mathematics, University of Auckland, Auckland, New Zealand
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, United States
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8
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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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Abstract
Aquaporins (AQPs ) are expressed in most exocrine and endocrine secretory glands. Consequently, summarizing the expression and functions of AQPs in secretory glands represents a daunting task considering the important number of glands present in the body, as well as the number of mammalian AQPs - thirteen. The roles played by AQPs in secretory processes have been investigated in many secretory glands. However, despite considerable research, additional studies are clearly needed to pursue our understanding of the role played by AQPs in secretory processes. This book chapter will focus on summarizing the current knowledge on AQPs expression and function in the gastrointestinal tract , including salivary glands, gastric glands, Duodenal Brunner's gland, liver and gallbladder, intestinal goblets cells, exocrine and endocrine pancreas, as well as few other secretory glands including airway submucosal glands, lacrimal glands, mammary glands and eccrine sweat glands.
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Affiliation(s)
- Christine Delporte
- Laboratory of Pathophysiological and Nutritional Biochemistry, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
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10
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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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Abstract
Ca
2+ oscillations, a widespread mode of cell signaling, were reported in non-excitable cells for the first time more than 25 years ago. Their fundamental mechanism, based on the periodic Ca
2+ exchange between the endoplasmic reticulum and the cytoplasm, has been well characterized. However, how the kinetics of cytosolic Ca
2+ changes are related to the extent of a physiological response remains poorly understood. Here, we review data suggesting that the downstream targets of Ca
2+ are controlled not only by the frequency of Ca
2+ oscillations but also by the detailed characteristics of the oscillations, such as their duration, shape, or baseline level. Involvement of non-endoplasmic reticulum Ca
2+ stores, mainly mitochondria and the extracellular medium, participates in this fine tuning of Ca
2+ oscillations. The main characteristics of the Ca
2+ exchange fluxes with these compartments are also reviewed.
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Affiliation(s)
- Geneviève Dupont
- Unité de Chronobiologie Théorique, Faculté des Sciences, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Laurent Combettes
- Interactions Cellulaires et Physiopathologie Hépatique, UMR-S 1174, Université Paris Sud, Orsay, France
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12
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Sneyd J, Means S, Zhu D, Rugis J, Won JH, Yule DI. Modeling calcium waves in an anatomically accurate three-dimensional parotid acinar cell. J Theor Biol 2016; 419:383-393. [PMID: 27155044 DOI: 10.1016/j.jtbi.2016.04.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/20/2016] [Accepted: 04/25/2016] [Indexed: 11/24/2022]
Abstract
We construct a model of calcium waves in a three-dimensional anatomically accurate parotid acinar cell, constructed from experimental data. Gradients of inositol trisphosphate receptor (IPR) density are imposed, with the IPR density being greater closer to the lumen, which has a branched structure, and inositol trisphosphate (IP3) is produced only at the basal membrane. We show (1) that IP3 equilibrates so quickly across the cell that it can be assumed to be spatially homogeneous; (2) spatial separation of the sites of IP3 action and IP3 production does not preclude the formation of stable oscillatory Ca2+ waves. However, these waves are not waves in the mathematical sense of a traveling wave with fixed profile. They result instead from a time delay between the Ca2+ rise in the apical and basal regions; (3) the ryanodine receptors serve to reinforce the Ca2+ wave, but are not necessary for the wave to exist; (4) a spatially independent model is not sufficient to study saliva secretion, although a one-dimensional model might be sufficient. Our results here form the first stages of the construction of a multiscale and multicellular model of saliva secretion in an entire acinus.
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Affiliation(s)
- James Sneyd
- Department of Mathematics, University of Auckland, New Zealand.
| | - Shawn Means
- Department of Mathematics, University of Auckland, New Zealand
| | - Di Zhu
- Department of Mathematics, University of Auckland, New Zealand
| | - John Rugis
- Department of Mathematics, University of Auckland, New Zealand
| | - Jong Hak Won
- Department of Pharmacology and Physiology, University of Rochester Medical Centre, Rochester, USA
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester Medical Centre, Rochester, USA
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Aquaporins in Salivary Glands: From Basic Research to Clinical Applications. Int J Mol Sci 2016; 17:ijms17020166. [PMID: 26828482 PMCID: PMC4783900 DOI: 10.3390/ijms17020166] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 01/20/2016] [Accepted: 01/21/2016] [Indexed: 01/06/2023] Open
Abstract
Salivary glands are involved in saliva secretion that ensures proper oral health. Aquaporins are expressed in salivary glands and play a major role in saliva secretion. This review will provide an overview of the salivary gland morphology and physiology of saliva secretion, and focus on the expression, subcellular localization and role of aquaporins under physiological and pathophysiological conditions, as well as clinical applications involving aquaporins. This review is highlighting expression and localization of aquaporins in human, rat and mouse, the most studied species and is pointing out possible difference between major salivary glands, i.e., parotid, submandibular and sublingual glands.
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