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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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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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3
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Involvement of aquaporin 5 in Sjögren's syndrome. Autoimmun Rev 2023; 22:103268. [PMID: 36621535 DOI: 10.1016/j.autrev.2023.103268] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 01/04/2023] [Indexed: 01/07/2023]
Abstract
Sjögren's syndrome (SS) is a chronic autoimmune disease with the pathological hallmark of lymphoplasmacytic infiltration of exocrine glands - more specifically salivary and lacrimal glands - resulting in a diminished production of tears and saliva (sicca syndrome). The pathophysiology underscoring the mechanisms of the sicca symptoms in SS has still yet to be unraveled but recent advances have identified a cardinal role of aquaporin-5 (AQP5) as a key player in saliva secretion as well as salivary gland epithelial cell dysregulation. AQP5 expression and localization are significantly altered in salivary glands from patients and mice models of the disease, shedding light on a putative mechanism accounting for diminished salivary flow. Furthermore, aberrant expression and localization of AQP5 protein partners, such as prolactin-inducible protein and ezrin, may account for altered AQP5 localization in salivary glands from patients suffering from SS and are considered as new players in SS development. This review provides an overview of the role of AQP5 in SS salivary gland epithelial cell dysregulation, focusing on its trafficking and protein-protein interactions.
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4
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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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5
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Fouani M, Basset CA, Jurjus AR, Leone LG, Tomasello G, Leone A. Salivary gland proteins alterations in the diabetic milieu. J Mol Histol 2021; 52:893-904. [PMID: 34212290 PMCID: PMC8487876 DOI: 10.1007/s10735-021-09999-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/12/2021] [Indexed: 11/25/2022]
Abstract
Salivary glands are considered the chief exocrine glands of the mouth and physiologically contribute to the maintenance of the homeostasis of the oral cavity. They consist of the parotid, submandibular and sublingual glands, which come in pairs and are collectively called the major glands, and the minor glands, which are much smaller and are dispersed throughout the buccal cavity. Salivary glands are distinguished by their size, amount of saliva secretion and their location in the oral cavity. Salivary glands pathophysiology has been a subject of interest in various worldwide metabolic disorders, including diabetes mellitus. Diabetes mellitus (DM), a global health concern, with a pathological imprint involved in vasculature, promotes microvascular and macrovascular complications among which periodontitis ranks sixth. Indeed, DM has also been directly associated with oral health lesions. Specifically, salivary glands in the context of diabetes have been a focal point of study and emphasis in the research field. There is evidence that relates salivary secretion content and diabetes progression. In this review, we present all the reported evidence of the deregulation of specific salivary proteins associated with the progression of diabetes in parallel with changes in salivary gland morphology, cellular architecture, and salivary secretion and composition more generally.
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Affiliation(s)
- Malak Fouani
- Department of Biomedicine, Neuroscience and Advanced Diagnostics, Institute of Human Anatomy and Histology, University of Palermo, Palermo, Italy
| | - Charbel A Basset
- Department of Biomedicine, Neuroscience and Advanced Diagnostics, Institute of Human Anatomy and Histology, University of Palermo, Palermo, Italy
| | - Abdo R Jurjus
- Department of Anatomy, Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | | | - Giovanni Tomasello
- Department of Biomedicine, Neuroscience and Advanced Diagnostics, Institute of Human Anatomy and Histology, University of Palermo, Palermo, Italy
| | - Angelo Leone
- Department of Biomedicine, Neuroscience and Advanced Diagnostics, Institute of Human Anatomy and Histology, University of Palermo, Palermo, Italy.
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6
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Hu J, Gao Y, Huang Q, Wang Y, Mo X, Wang P, Zhang Y, Xie C, Li D, Yao J. Flotillin-1 Interacts With and Sustains the Surface Levels of TRPV2 Channel. Front Cell Dev Biol 2021; 9:634160. [PMID: 33634132 PMCID: PMC7900159 DOI: 10.3389/fcell.2021.634160] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 01/20/2021] [Indexed: 11/29/2022] Open
Abstract
Transient receptor potential vanilloid subtype 2 (TRPV2) channel is a polymodal receptor regulating neuronal development, cardiac function, immunity and oncogenesis. The activity of TRPV2 is regulated by the molecular interactions in the subplasmalemmel signaling complex. Here by yeast two-hybrid screening of a cDNA library of mouse dorsal root ganglia (DRG) and patch clamp electrophysiology, we identified that flotillin-1, the lipid raft-associated protein, interacts with TRPV2 channel and regulates its function. The interaction between TRPV2 and flotillin-1 was validated through co-immuoprecipitation in situ using endogenous DRG neurons and the recombinant expression model in HEK 293T cells. Fluorescent imaging and bimolecular fluorescence complementation (BiFC) further revealed that flotillin-1 and TRPV2 formed a functional complex on the cell membrane. The presence of flotillin-1 enhanced the whole-cell current density of TRPV2 via increasing its surface expression levels. Using site-specific mapping, we also uncovered that the SPFH (stomatin, prohibitin, flotillin, and HflK/C) domain of flotillin-1 interacted with TRPV2 N-termini and transmembrane domains 1–4, respectively. Our findings therefore demonstrate that flotillin-1 is a key element in TRPV2 signaling complex and modulates its cellular response.
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Affiliation(s)
- Juan Hu
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Yue Gao
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Qian Huang
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Yuanyuan Wang
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Xiaoyi Mo
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Peiyu Wang
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Youjing Zhang
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Chang Xie
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Dongdong Li
- Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, Sorbonne Université, Paris, France
| | - Jing Yao
- State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
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D’Agostino C, Elkashty OA, Chivasso C, Perret J, Tran SD, Delporte C. Insight into Salivary Gland Aquaporins. Cells 2020; 9:cells9061547. [PMID: 32630469 PMCID: PMC7349754 DOI: 10.3390/cells9061547] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/23/2020] [Accepted: 06/23/2020] [Indexed: 12/18/2022] Open
Abstract
The main role of salivary glands (SG) is the production and secretion of saliva, in which aquaporins (AQPs) play a key role by ensuring water flow. The AQPs are transmembrane channel proteins permeable to water to allow water transport across cell membranes according to osmotic gradient. This review gives an insight into SG AQPs. Indeed, it gives a summary of the expression and localization of AQPs in adult human, rat and mouse SG, as well as of their physiological role in SG function. Furthermore, the review provides a comprehensive view of the involvement of AQPs in pathological conditions affecting SG, including Sjögren's syndrome, diabetes, agedness, head and neck cancer radiotherapy and SG cancer. These conditions are characterized by salivary hypofunction resulting in xerostomia. A specific focus is given on current and future therapeutic strategies aiming at AQPs to treat xerostomia. A deeper understanding of the AQPs involvement in molecular mechanisms of saliva secretion and diseases offered new avenues for therapeutic approaches, including drugs, gene therapy and tissue engineering. As such, AQP5 represents a potential therapeutic target in different strategies for the treatment of xerostomia.
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Affiliation(s)
- Claudia D’Agostino
- Laboratory of Pathophysiological and Nutritional Biochemistry, Faculty of Medicine, Université Libre de Bruxelles, 808 Route de Lennik, Blg G/E CP 611, B-1070 Brussels, Belgium; (C.D.); (C.C.); (J.P.)
| | - Osama A. Elkashty
- McGill Craniofacial Tissue Engineering and Stem Cells Laboratory, Faculty of Dentistry, McGill University, Montreal, QC H3A 0C7, Canada; (O.A.E.); (S.D.T.)
- Oral Pathology Department, Faculty of Dentistry, Mansoura University, 35516 Mansoura, Egypt
| | - Clara Chivasso
- Laboratory of Pathophysiological and Nutritional Biochemistry, Faculty of Medicine, Université Libre de Bruxelles, 808 Route de Lennik, Blg G/E CP 611, B-1070 Brussels, Belgium; (C.D.); (C.C.); (J.P.)
| | - Jason Perret
- Laboratory of Pathophysiological and Nutritional Biochemistry, Faculty of Medicine, Université Libre de Bruxelles, 808 Route de Lennik, Blg G/E CP 611, B-1070 Brussels, Belgium; (C.D.); (C.C.); (J.P.)
| | - Simon D. Tran
- McGill Craniofacial Tissue Engineering and Stem Cells Laboratory, Faculty of Dentistry, McGill University, Montreal, QC H3A 0C7, Canada; (O.A.E.); (S.D.T.)
| | - Christine Delporte
- Laboratory of Pathophysiological and Nutritional Biochemistry, Faculty of Medicine, Université Libre de Bruxelles, 808 Route de Lennik, Blg G/E CP 611, B-1070 Brussels, Belgium; (C.D.); (C.C.); (J.P.)
- Correspondence: ; Tel.: +32-2-5556210
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8
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El Sadik A, Mohamed E, El Zainy A. Postnatal changes in the development of rat submandibular glands in offspring of diabetic mothers: Biochemical, histological and ultrastructural study. PLoS One 2018; 13:e0205372. [PMID: 30304036 PMCID: PMC6179275 DOI: 10.1371/journal.pone.0205372] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 09/23/2018] [Indexed: 11/21/2022] Open
Abstract
Development and maturation of submandibular salivary glands are influenced by intrauterine diabetic environment. Several studies investigated the effects of diabetes on the salivary glands. However, the effects of maternal diabetes on the submandibular glands of the offspring was not properly examined. Therefore, the present study was designed to describe the changes in the development of the submandibular glands of the offspring of diabetic mothers. The submandibular glands of the offspring of Streptozotocin (STZ)-induced diabetic female rats were examined at two and four weeks after birth. Detection of mRNA demonstrated that maternal diabetes affects the level of different indicators. The reduction of expression of epidermal growth factor (EGF); a protein mitogen, cytokeratin 5 (CK5); an epithelial cell progenitor, CK7 and aquaporin 5 (AQP5); differentiation markers and B cell lymphoma 2 (Bcl2); an antiapoptotic marker were found. Increase in Bcl2-associated X protein (Bax); an apoptotic marker was detected. These changes indicate their effects on saliva secretion, glands tumorigenesis, growth of normal oral flora and oral microbes, with decreased protein synthesis and production of xerostomia and dental caries. Loss of normal glandular architecture, significant increase in fibrosis, by the detection of collagen fibers, and stagnation of secretory granules were found with atrophic changes in the acinar cells. Marked defect of polysaccharides in the acinar cells, denoting functional changes, was manifested by significant reduction of the intensity of periodic acid-Schiff (PAS) reaction. The positive immunoreactivity of caspase-3, denoting cellular apoptosis, and minimal reaction of alpha-smooth muscle actin (α SMA) and proliferating cell nuclear antigen (PCNA) were evident in the offspring of diabetic mothers. We conclude that maternal diabetes produces degenerative effects in the structure and function of the submandibular salivary glands of the offspring, reflecting possible influences on their secretory activity affecting oral and digestive health.
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Affiliation(s)
- Abir El Sadik
- Department of Anatomy and Embryology, Faculty of Medicine, Cairo University, Cairo, Egypt
- * E-mail:
| | - Enas Mohamed
- Department of Anatomy and Embryology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Ahmed El Zainy
- Department of Anatomy and Embryology, Faculty of Medicine, Cairo University, Cairo, Egypt
- Qassim University, Qassim, KSA
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Biswas R, Ahn JC, Moon JH, Kim J, Choi YH, Park SY, Chung PS. Low-level laser therapy with 850 nm recovers salivary function via membrane redistribution of aquaporin 5 by reducing intracellular Ca 2+ overload and ER stress during hyperglycemia. Biochim Biophys Acta Gen Subj 2018; 1862:1770-1780. [PMID: 29751100 DOI: 10.1016/j.bbagen.2018.05.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 12/28/2022]
Abstract
The overall goal is to study the effect of low-level laser therapy (LLLT) on membrane distribution of major water channel protein aquaporin 5 (AQP5) in salivary gland during hyperglycemia. Par C10 cells treated with high glucose (50 mM) showed a reduced membrane distribution of AQP5. The functional expression of AQP5 was downregulated due to intracellular Ca2+ overload and ER stress. This reduction in AQP5 expression impairs water permeability and therefore results in hypo-salivation. A reduced salivary flow was also observed in streptozotocin (STZ)-induced diabetic mice model and the expression of AQP5 and phospho-AQP5 was downregulated. Low-level laser treatment with 850 nm (30 mW, 10 min = 18 J/cm2) reduced ER stress and recovered AQP5 membrane distribution via serine phosphorylation in the cells. In the STZ-induced diabetic mouse, LLLT with 850 nm (60 J/cm2) increased salivary flow and upregulated of AQP5 and p-AQP5. ER stress was also reduced via downregulation of caspase 12 and CHOP. In silico analysis confirmed that the serine 156 is one of the most favorable phosphorylation sites of AQP5 and may contribute to the stability of the protein. Therefore, this study suggests high glucose inhibits phosphorylation-dependent AQP5 membrane distribution. High glucose induces intracellular Ca2+ overload and ER stress that disrupt AQP5 functional expression. Low-level laser therapy with 850 nm improves salivary function by increasing AQP5 membrane distribution in hyperglycemia-induced hyposalivation.
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Affiliation(s)
- Raktim Biswas
- Laser Translational Clinical Trial Centre, Dankook University Hospital, Cheonan, Republic of Korea
| | - Jin Chul Ahn
- Department of Biomedical Science, College of Medicine, Dankook University, Cheonan, Republic of Korea
| | - Jeong Hwan Moon
- Laser Translational Clinical Trial Centre, Dankook University Hospital, Cheonan, Republic of Korea; Department of Otolaryngology-Head and Neck Surgery, Dankook University College of Medicine, Cheonan, Republic of Korea
| | - Jungbin Kim
- Laser Translational Clinical Trial Centre, Dankook University Hospital, Cheonan, Republic of Korea
| | - Young-Hoon Choi
- Laser Translational Clinical Trial Centre, Dankook University Hospital, Cheonan, Republic of Korea
| | - So Young Park
- Laser Translational Clinical Trial Centre, Dankook University Hospital, Cheonan, Republic of Korea
| | - Phil-Sang Chung
- Laser Translational Clinical Trial Centre, Dankook University Hospital, Cheonan, Republic of Korea; Department of Otolaryngology-Head and Neck Surgery, Dankook University College of Medicine, Cheonan, Republic of Korea.
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10
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Bhattarai KR, Lee HY, Kim SH, Kim HR, Chae HJ. Ixeris dentata Extract Increases Salivary Secretion through the Regulation of Endoplasmic Reticulum Stress in a Diabetes-Induced Xerostomia Rat Model. Int J Mol Sci 2018; 19:ijms19041059. [PMID: 29614832 PMCID: PMC5979381 DOI: 10.3390/ijms19041059] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 03/20/2018] [Accepted: 03/28/2018] [Indexed: 12/14/2022] Open
Abstract
This study aimed to investigate the molecular mechanism of diabetes mellitus (DM)-induced dry mouth and an application of natural products from Ixeris dentata (IXD), a recently suggested regulator of amylase secretion in salivary cells. Vehicle-treated or diabetic rats were orally treated with either water or an IXD extract for 10 days to observe the effect on salivary flow. We found that the IXD extract increased aquaporin 5 (AQP5) and alpha-amylase protein expression in the submandibular gland along with salivary flow rate. Similarly, the IXD extract and its purified compound increased amylase secretion in high glucose-exposed human salivary gland cells. Furthermore, increased endoplasmic reticulum stress response in the submandibular gland of diabetic rats was inhibited by treatment with the IXD extract, suggesting that IXD extract treatment improves the ER environment by increasing the protein folding capacity. Thus, pharmacological treatment with the IXD extract is suggested to relieve DM-induced dry mouth symptoms.
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Affiliation(s)
- Kashi Raj Bhattarai
- Department of Pharmacology and Institute of New Drug Development, School of Medicine, Chonbuk National University, Jeonju 54896, Korea.
| | - Hwa-Young Lee
- Department of Pharmacology and Institute of New Drug Development, School of Medicine, Chonbuk National University, Jeonju 54896, Korea.
| | - Seung-Hyun Kim
- College of Pharmacy, Yonsei Institute of Pharmaceutical Science, Yonsei University, Incheon 406-840, Korea.
| | - Hyung-Ryong Kim
- Graduate School, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, Korea.
| | - Han-Jung Chae
- Department of Pharmacology and Institute of New Drug Development, School of Medicine, Chonbuk National University, Jeonju 54896, Korea.
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11
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Munemasa T, Mukaibo T, Kondo Y, Masaki C, Kusuda Y, Miyagi Y, Tsuka S, Hosokawa R, Nakamoto T. Salivary gland hypofunction in KK-A y type 2 diabetic mice. J Diabetes 2018; 10:18-27. [PMID: 28299899 DOI: 10.1111/1753-0407.12548] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 02/27/2017] [Accepted: 03/12/2017] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Hypofunction of different organs in the body is associated with diabetes, including in the oral cavity. Diabetes is often associated with xerostomia, but the underlying mechanism is not well characterized. Thus, the mechanisms underlying diabetes-induced xerostomia were investigated in this study in KK-A y mice as an experimental model of type 2 diabetes. METHODS The mechanisms involved in diabetes-induced xerostomia were investigated using the ex vivo glandular perfusion technique, histological analysis, and immunohistochemical and intracellular signaling analyses. RESULTS Ex vivo submandibular gland secretions from KK-Ay mice decreased by 30% following stimulation with 0.3 μmol/L carbachol (CCh), a cholinergic agonist. Acinar cell weight was comparable between KK-Ay and control mice, whereas duct cell weight was significantly greater in KK-Ay mice. Concentrations of Na+ and Cl- in the secreted saliva decreased significantly in KK-Ay mice, supporting the finding of increased ductal tissue in KK-Ay mice. Immunohistochemistry revealed no significant differences between KK-Ay and control mice in terms of the expression of Cl- and water channels, Na+ -K+ -2Cl- cotransporters, and membrane proteins critical for fluid secretion. Cellular signaling analysis revealed that the increase in [Ca2+ ]i in response to 0.3 μmol/L CCh was reduced by 30% in KK-Ay mice, although there was no significant difference in the thapsigargin (1.0 μmol/L)-induced increase in store-depleted calcium between KK-Ay and control mice. CONCLUSIONS These results demonstrate that submandibular fluid secretion is diminished in KK-Ay mice because of a diminished increase in [Ca2+ ]i . Duct cell weight increased in KK-Ay mice, possibly leading to increased ion reabsorption and thus decreased Na+ and Cl- concentrations in the secreted saliva.
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Affiliation(s)
- Takashi Munemasa
- Division of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Fukuoka, Japan
| | - Taro Mukaibo
- Division of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Fukuoka, Japan
| | - Yusuke Kondo
- Division of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Fukuoka, Japan
| | - Chihiro Masaki
- Division of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Fukuoka, Japan
| | - Yuichiro Kusuda
- Division of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Fukuoka, Japan
| | - Yuta Miyagi
- Division of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Fukuoka, Japan
| | - Shintaro Tsuka
- Division of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Fukuoka, Japan
| | - Ryuji Hosokawa
- Division of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Fukuoka, Japan
| | - Tetsuji Nakamoto
- Department of Prosthodontics, Matsumoto Dental University, Nagano, Japan
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12
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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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13
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Integrating genomic data from high-throughput studies with computational modeling reveals differences in the molecular basis of hyposalivation between type 1 and type 2 diabetes. Clin Oral Investig 2017; 22:151-159. [PMID: 28255753 DOI: 10.1007/s00784-017-2094-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 02/22/2017] [Indexed: 01/05/2023]
Abstract
OBJECTIVES Both type 1 and type 2 diabetes are accompanied by a high prevalence of hyposalivation (decreased salivary secretion), resulting in oral tissue damage. However, the molecular basis for the hyposalivation is yet unknown. Identifying genes and proteins that account for diabetes-related hyposalivation will help understanding the basis for this condition and identifying disease biomarkers in saliva. MATERIALS AND METHODS We integrated genomic data from 110 high-throughput studies with computational modeling, to explore the relationship between diabetes and salivary glands on a genomic scale. RESULTS A significant overlap exists between genes that are altered in both types of diabetes and genes that are expressed in salivary glands; 87 type 1 diabetes and 34 type 2 diabetes associated genes are also common to salivary glands. However, the overlap between these genes is not significant. CONCLUSIONS Type 1 and type 2 diabetes associated genes are involved in the salivary secretion process, but mostly at different parts of it. This suggests that type 1 and type 2 diabetes impair salivary secretion by affecting different processes in the salivary tissue. CLINICAL RELEVANCE The genomic characteristics of Type 1 and type 2 diabetes may explain differences in salivary gland tissues morphology and saliva composition in people with diabetes, and suggest candidate proteins for diabetes salivary biomarkers.
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Stewart CR, Obi N, Epane EC, Akbari AA, Halpern L, Southerland JH, Gangula PR. Effects of Diabetes on Salivary Gland Protein Expression of Tetrahydrobiopterin and Nitric Oxide Synthesis and Function. J Periodontol 2016; 87:735-41. [PMID: 26777763 PMCID: PMC4882217 DOI: 10.1902/jop.2016.150639] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Xerostomia is defined as dry mouth resulting from a change in the amount or composition of saliva and is often a major oral health complication associated with diabetes mellitus (DM). Studies have shown that xerostomia is more common in females at the onset of DM. Evidence suggests that nitric oxide (NO) plays a critical role in healthy salivary gland function. However, the specific mechanisms by which NO regulates salivary gland function at the onset of DM have yet to be determined. This study has two aims: 1) to determine whether protein expression or dimerization of NO synthase enzymes (neuronal [nNOS] and endothelial [eNOS]) are altered in the onset of diabetic xerostomia; and 2) to determine whether the changes in nNOS/eNOS protein expression or dimerization are correlated with changes in NO cofactor tetrahydrobiopterin (BH4) biosynthetic enzymes (guanosine triphosphate cyclohydrolase-1 and dihydrofolate reductase). METHODS Functional and Western blot studies were performed in streptozotocin-induced and control Sprague-Dawley female rats with DM (type 1 [t1DM]) using standardized protocols. Confirmation of xerostomia was determined by increased water intake and decreased salivary flow rate. RESULTS The results showed that in female rats with DM, salivary hypofunction is correlated with decreased submandibular and parotid gland sizes. The results also show a decrease in NOS and BH4 biosynthetic enzyme in submandibular glands. CONCLUSIONS These results indicate that a decrease in submandibular NO-BH4 protein expression may provide insight pertaining to mechanisms for the development of hyposalivation in DM-induced xerostomia. Furthermore, understanding the role of the NO-BH4 pathway may give insight into possible treatment options for the patient with DM experiencing xerostomia.
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Affiliation(s)
| | - Nneka Obi
- School of Dentistry, Meharry Medical College, Nashville, TN
| | - Elodie C Epane
- School of Dentistry, Meharry Medical College, Nashville, TN
| | | | - Leslie Halpern
- Department of Oral Surgery, School of Dentistry, Meharry Medical College
| | | | - Pandu R Gangula
- School of Dentistry, Meharry Medical College, Nashville, TN
- Center for Women's Health Research, School of Medicine, Meharry Medical College
- Department of Physiology, School of Medicine, Meharry Medical College
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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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Lilliu MA, Solinas P, Cossu M, Puxeddu R, Loy F, Isola R, Quartu M, Melis T, Isola M. Diabetes causes morphological changes in human submandibular gland: a morphometric study. J Oral Pathol Med 2014; 44:291-5. [PMID: 25154984 DOI: 10.1111/jop.12238] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2014] [Indexed: 12/13/2022]
Abstract
BACKGROUND Dataon structural alterations in human diabetic salivary glands are scanty and conflicting. The goal of this study is based on the evaluation of the morphological changes in submandibular glands of subjects with well-controlled diabetes and without evident salivary malfunctions. METHODS Submandibular gland pieces from diabetic and non-diabetic patients were fixed, dehydrated, and processed to obtain sections for light and electron microscopy. Randomly selected micrographs were statistically analyzed to reveal variations in serous acini. RESULTS Morphometrical evaluation allowed us to reveal significant changes such as enlargement of acinar and granule size, reduction of mitochondrial size, increased density of microbuds and protrusions along luminal membranes. CONCLUSIONS The results indicate that diabetes affects submandibular gland structure even when glandular function appears unaltered and suggest that morphological changes reflect functional changes chiefly regarding the secretory activity.
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Affiliation(s)
- Maria Alberta Lilliu
- Department of Biomedical Sciences, University of Cagliari, Monserrato, CA, Italy
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17
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Aquaporins in salivary glands and pancreas. Biochim Biophys Acta Gen Subj 2014; 1840:1524-32. [DOI: 10.1016/j.bbagen.2013.08.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 08/07/2013] [Accepted: 08/08/2013] [Indexed: 12/23/2022]
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Gresz V, Horvath A, Gera I, Nielsen S, Zelles T. Immunolocalization of AQP5 in resting and stimulated normal labial glands and in Sjögren's syndrome. Oral Dis 2014; 21:e114-20. [PMID: 24661359 DOI: 10.1111/odi.12239] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/13/2014] [Accepted: 03/13/2014] [Indexed: 01/05/2023]
Abstract
OBJECTIVE In our current work, in vivo examination of AQP5 distribution in labial salivary glands following stimulation of secretion has been carried out in normal individuals and in patients with Sjögren's syndrome. SUBJECTS AND METHODS For this study, we selected five patients with primary Sjögren's syndrome (mean age 62.4 ± 10.6 s.d. years) diagnosed in accordance with the European Cooperative Community classification criteria. There were five patients (mean age 27 ± 2.5 s.d. years) in the control group. The subcellular distribution of AQP5 in human labial gland biopsies was determined with light and immunoelectron microscopy before and 30 min after administration of oral pilocarpine. RESULTS In unstimulated control and Sjögren's labial glands, AQP5 is about 90% localized in the apical plasma membrane, with only rarely associated gold particles with intracellular membrane structures. We have found no evidence of pilocarpine-induced changes in localization of AQP5 in either healthy individuals or patients with Sjögren's syndrome. CONCLUSIONS Our studies indicate that neither Sjögren's syndrome itself, nor muscarinic cholinergic stimulation in vivo caused any significant changes in the distribution of AQP5 in the labial salivary gland cells.
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Affiliation(s)
- V Gresz
- Department of Oral Diagnostics, Semmelweis University, Budapest, Hungary
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Ding C, Cong X, Zhang Y, Yang NY, Li SL, Wu LL, Yu GY. Hypersensitive mAChRs are involved in the epiphora of transplanted glands. J Dent Res 2014; 93:306-12. [PMID: 24389807 DOI: 10.1177/0022034513519107] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Autologous transplantation of the submandibular gland is an effective treatment for severe dry eye syndrome. However, more than 40% of patients experience epiphora 3 to 6 months after transplantation. The underlying mechanism of epiphora remains to be elucidated. To investigate the potential roles of muscarinic acetylcholine receptors (mAChRs) in the induction of epiphora in transplanted glands, we assessed and found elevated mRNA and protein expression of M1- and M3-mAChR in transplanted glands from epiphora patients. The content of inositol 1, 4, 5-trisphosphate was also elevated. Moreover, carbachol (5 and 10 µM) induced greater increase of [Ca(2+)]i in isolated epiphora submandibular cells than in controls. Although aquaporin-5 (AQP5) content and distribution in the apical and lateral plasma of epiphora glands did not change, AQP5 content was reduced in lipid microdomains (lipid rafts and caveolae) but increased in non-lipid microdomains compared with controls. Carbachol (10 µM) increased the ratio of non-lipid microdomain to total AQP5 in the cultured control submandibular gland tissue. Taken together, these results indicated that hypersensitive mAChRs might be involved in the epiphora of transplanted submandibular glands by modulating AQP5 trafficking.
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Affiliation(s)
- C Ding
- Center Laboratory and Center for Salivary Gland Diseases, Peking University School and Hospital of Stomatology, 22 Zhong Guan Cun South St., Beijing, 100081, P.R. China
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Pei L, Yang G, Jiang J, Jiang R, Deng Q, Chen B, Gan X. Expression of aquaporins in prostate and seminal vesicles of diabetic rats. J Sex Med 2013; 10:2975-85. [PMID: 23981690 DOI: 10.1111/jsm.12276] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Aquaporins (AQPs) are membrane proteins that facilitate the movement of water and many small solutes across biological membranes. Seminal fluid is primarily produced by prostate and seminal vesicles, and its production may potentially be mediated by many mechanisms related to transudation of fluid. Epidemiological data suggest that semen volume in diabetic men is significantly less than in nondiabetic men. AIM To investigate the change in volume of secretions of the prostate and seminal vesicles in diabetic rats and its association with the expression of AQPs 1-4. METHODS Twenty male Sprague Dawley rats were randomly divided among 4- and 6-week diabetic groups and 4- and 6-week control groups. Prostate and seminal vesicle secretions were collected and measured, and levels of expression of AQPs 1-4 were determined by immunohistochemical study and Western blot. MAIN OUTCOME MEASURES The levels of expression of AQPs 1-4 were determined in the prostate and seminal vesicles of diabetic rats by Western blot and immunohistochemical study. RESULTS Plasma glucose was significantly higher in diabetic model groups than in controls (P < 0.05). The weights of secretions of the prostate and seminal vesicles were significantly lower in diabetic model groups (P < 0.05). The levels of expression of AQPs 1 and 4 in seminal vesicles were significantly lower in diabetic model groups (P < 0.05). There was no difference in the level of expression of AQP3 in seminal vesicles among the groups. The levels of expression of AQPs 1, 3, and 4 in prostate were significantly lower in diabetic model groups (P < 0.05). AQP2 was not detectable in the prostate or seminal vesicles of any of the groups. CONCLUSIONS Decreased weight of prostate secretions in diabetic rats may be partly due to decreased levels of AQPs 1, 3, and 4 in prostatic tissue. Decreased weight of seminal vesicle secretions in diabetic rats may be partly due to decreased levels of AQP1 and AQP4 in seminal vesicles. There is no relationship between the expression of AQPs 1-4 and the duration of disease.
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Affiliation(s)
- Lijun Pei
- Department of Nuclear Medicine, Affiliated Hospital, Luzhou Medical College, Luzhou, China
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Pei L, Jiang J, Jiang R, Ouyang F, Yang H, Cheng Y, Fan Z. Expression of aquaporin proteins in vagina of diabetes mellitus rats. J Sex Med 2012; 10:342-9. [PMID: 23110393 DOI: 10.1111/j.1743-6109.2012.02989.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
INTRODUCTION Aquaporins (AQPs) are membrane proteins that facilitate water movement across biological membranes. Vaginal lubrication may be mediated by blood flow and other potential mechanisms related to transudation of fluid. The most common female sexual dysfunction in diabetes is inadequate vaginal lubrication. AIM To investigate the expression of AQP1-3 in vaginal tissue of diabetes mellitus rats. METHODS Female Sprague-Dawley rats (N = 20) were randomly divided into group A (12-week-old nondiabetic control, N = 5), group B (16-week-old nondiabetes control, N = 5), group C (12-week-old diabetes mellitus rats, N = 5), and group D (16-week-old diabetes mellitus rats, N = 5). Vaginal fluid was measured by fluid weight absorbed by cotton swabs after pelvic nerve electrostimulation and anterior vaginal tissue was dissected for determining the expression of AQP1-3 by immunohistochemical study and Western blot. MAIN OUTCOME MEASURES The expression of AQP1-3 was determined in the vagina of diabetes mellitus rats by Western blot. RESULTS There are no significant differences in serum estradiol concentrations of rats among these groups (P > 0.05). Vaginal fluid was significantly lower in group C (2.7 ± 0.67 mg) and group D (2.5 ± 1.03 mg) than in group A (5.74 ± 1.23 mg) and group B (5.5 ± 1.08 mg) (P < 0.05), respectively. The protein expressions of AQP1-3 were significantly lower in group C (43.40 ± 4.83, 60.60 ± 12.80, and 59.60 ± 6.95) and group D (20.81 ± 2.86, 47.80 ± 11.43, and 54.20 ± 5.26) than in group A (116.62 ± 3.21, 110.81 ± 8.044, and 108.80 ± 4.97) and group B (122.12 ± 14.54, 111.21 ± 15.07, and 106.40 ± 4.16) (P < 0.05), respectively. CONCLUSIONS Decreased vaginal fluid in diabetes mellitus rats after electrostimulation may be partly due to estrogen-independent decreases of AQP1-3 in vaginal tissue.
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Affiliation(s)
- Lijun Pei
- Department of Cardiovascular Disease, Affiliated Hospital, Luzhou Medical College, Luzhou, China
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Soyfoo MS, Bolaky N, Depoortere I, Delporte C. Relationship between aquaporin-5 expression and saliva flow in streptozotocin-induced diabetic mice? Oral Dis 2012; 18:501-5. [PMID: 22273265 DOI: 10.1111/j.1601-0825.2011.01902.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To investigate the expression and distribution of AQP5 in submandibular acinar cells from sham- and streptozotocin (STZ)-treated mice in relation to the salivary flow. METHODS Mice were sham or STZ injected. Distribution of AQP5 subcellular expression in submandibular glands was determined by immunohistochemistry. AQP5 labelling indices (LI), reflecting AQP5 subcellular distribution, were determined in acinar cells. Western blotting was performed to determine the expression of AQP5 in submandibular glands. Blood glycaemia and osmolality and saliva flow rates were also determined. RESULTS AQP5 immunoreactivity was primarily located at the apical and apical-basolateral membranes of submandibular gland acinar cells from sham- and STZ-treated mice. No significant differences in AQP5 protein levels were observed between sham- and STZ-treated mice. Compared to sham-treated mice, STZ-treated mice had significant increased glycaemia, while no significant differences in blood osmolality were observed. Saliva flow rate was significantly decreased in STZ-treated mice as compared to sham-treated mice. CONCLUSIONS In STZ-treated mice, significant reduction in salivary flow rate was observed without any concomitant modification in AQP5 expression and localization.
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Affiliation(s)
- M S Soyfoo
- Laboratory of Biological Chemistry and Nutrition, Université Libre de Bruxelles, Brussels, Belgium
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Ibuki FK, Simões A, Nicolau J, Nogueira FN. Laser irradiation affects enzymatic antioxidant system of streptozotocin-induced diabetic rats. Lasers Med Sci 2012; 28:911-8. [PMID: 22869159 DOI: 10.1007/s10103-012-1173-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 07/16/2012] [Indexed: 12/26/2022]
Abstract
The aim of the present study was to analyze the effect of low-power laser irradiation in the antioxidant enzymatic system of submandibular (SMG) and parotid (PG) salivary glands of streptozotocin-induced diabetic rats. The animals were randomly divided into six groups: three diabetic groups (D0, D5, and D20) and three non-diabetic groups (C0, C5, and C20), according to laser dose received (0, 5, and 20 J/cm(2), respectively). Areas of approximately 1 cm(2) were demarcated in the salivary glands (each parotid and both submandibular glands) and after irradiated according to Simões et.al. (Lasers Med Sci 24:202-208, 2009). A diode laser (660 nm/100 mW) was used, with laser beam spot of 0.0177 cm(2). The group treated with 5 J/cm(2) laser dose was subjected to irradiation for 1 min and 4 s (total irradiation time) and the group treated with 20 J/cm(2) laser dose was subjected to irradiation for 4 min and 16 s. Twenty-four hours after irradiation the animals were euthanized and the salivary glands were removed for biochemical analysis. The total antioxidant values (TA), the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase enzymes were determined. SOD and CAT activities, as well as TA were higher in SMG of irradiated diabetic rats. However, in SMG of non-diabetic rats, laser irradiation decreased TA values and led to an increase in the CAT activity. In addition, there was a decrease in the activity of CAT in PG of diabetic and non-diabetic animals after laser irradiation. According to the results of the present study, low-power laser irradiation can affect the enzymatic antioxidant system of salivary glands of streptozotocin-induced diabetic rats.
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Affiliation(s)
- Flavia Kazue Ibuki
- Departamento de Biomateriais e Biologia Oral, Faculdade de Odontologia, Universidade de São Paulo (USP), São Paulo, Brazil, 05508-000
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Sialic acid reduction in the saliva of streptozotocin induced diabetic rats. Arch Oral Biol 2012; 57:1189-93. [PMID: 22421632 DOI: 10.1016/j.archoralbio.2012.02.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 02/10/2012] [Accepted: 02/13/2012] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Diabetes causes changes in the salivary glands and in the composition of saliva, as well as symptoms such as dry mouth and hyposalivation. Therefore, this study aimed at investigating changes in salivary secretion and composition, in response to parasympathetic stimuli, in diabetic rats induced with streptozotocin. DESIGN Diabetes was induced by a single intraperitoneal injection of streptozotocin. Thirty days after diabetes induction, the animals were anaesthetized and salivation was stimulated by an intraperitoneal injection of Pilocarpine (0.6mg/kg body weight) dissolved in distilled water. Saliva was collected for 40min and immediately stored at -80°C until analysis. The salivary flow rate, amount of total protein, amylase and peroxidase activities, and free and total sialic acid contents were measured. RESULTS Salivary flow rate was reduced in the diabetic group (p<0.05). Moreover, increases in total protein amount and in amylase and peroxidase activities were observed in diabetic animals. No difference was observed for free sialic acid content between groups. On the other hand, a significantly decrease in the total sialic acid content was observed in the diabetic group (p<0.05). CONCLUSIONS Our findings suggest that a decrease in sialic acid in the saliva of diabetic animals can be related to xerostomia reported by diabetic patients. However, further clinical trials are needed to verify if the decrease in sialic acid also occurs in human saliva.
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