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Huang KT, Wagner LE, Takano T, Lin XX, Bagavant H, Deshmukh U, Yule DI. Dysregulated Ca 2+ signaling, fluid secretion, and mitochondrial function in a mouse model of early Sjögren's syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.19.585719. [PMID: 38562738 PMCID: PMC10983907 DOI: 10.1101/2024.03.19.585719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Saliva is essential for oral health. The molecular mechanisms leading to physiological fluid secretion are established, but factors that underlie secretory hypofunction, specifically related to the autoimmune disease Sjögren's syndrome (SS) are not fully understood. SS-like disease was induced by the treatment with 5,6-Dimethyl-9-oxo-9H-xanthene-4-acetic acid (DMXAA), an activator of the stimulator of the interferon gene (STING) pathway. This mouse model mimics exposure to foreign cytoplasmic ribonucleotides occurring following viral and bacterial infection and thought to be an initiating event in SS. Neurotransmitter-stimulated increases in cytoplasmic [Ca2+] are central to stimulating fluid secretion, primarily by increasing the activity of the Ca2+-activated Cl- channel, TMEM16a. Paradoxically, in DMXAA-treated mice in vivo imaging demonstrated that neural-stimulation resulted in greatly enhanced Ca2+ levels when a significant reduction in fluid secretion was observed. Notably, in the disease model, the spatiotemporal characteristics of the Ca2+ signals were altered to result in global rather than largely apically confined Ca2+ rises observed physiologically. Notwithstanding the augmented Ca2+ signals, muscarinic stimulation resulted in reduced activation of TMEM16a, although there were no changes in channel abundance or absolute sensitivity to Ca2+. However, super-resolution microscopy revealed a disruption in the localization of Inositol 1,4,5-trisphosphate receptor Ca2+ release channels in relation to TMEM16a. Appropriate Ca2+ signaling is also pivotal for mitochondrial morphology and bioenergetics and secretion is an energetically expensive process. Disrupted mitochondrial morphology, a depolarized mitochondrial membrane potential, and reduced oxygen consumption rate were observed in DMXAA-treated animals compared to control animals. We report that early in SS disease, dysregulated Ca2+ signals lead to decreased fluid secretion and disrupted mitochondrial function contributing to salivary gland hypofunction and likely the progression of SS disease.
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Affiliation(s)
- Kai-Ting Huang
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, NY. 14526
| | - Larry E. Wagner
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, NY. 14526
| | - Takahiro Takano
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, NY. 14526
| | - Xiao-Xuan Lin
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, NY. 14526
| | - Harini Bagavant
- Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, 825 NE 13 Street, Oklahoma City, OK 73104
| | - Umesh Deshmukh
- Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, 825 NE 13 Street, Oklahoma City, OK 73104
| | - David I. Yule
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, NY. 14526
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Wahl AM, Takano T, Su S, Warner BM, Perez P, Sneyd J, Yule DI. Structural and functional analysis of salivary intercalated duct cells reveals a secretory phenotype. J Physiol 2023; 601:4539-4556. [PMID: 37724716 PMCID: PMC10591963 DOI: 10.1113/jp285104] [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: 06/02/2023] [Accepted: 08/30/2023] [Indexed: 09/21/2023] Open
Abstract
Currently, all salivary ducts (intercalated, striated and collecting) are assumed to function broadly in a similar manner, reclaiming ions that were secreted by the secretory acinar cells while preserving fluid volume and delivering saliva to the oral cavity. Nevertheless, there has been minimal investigation into the structural and functional differences between distinct types of salivary duct cells. Therefore, in this study, the expression profile of proteins involved in stimulus-secretion coupling, as well as the function of the intercalated duct (ID) and striated duct cells, was examined. Particular focus was placed on defining differences between distinct duct cell populations. To accomplish this, immunohistochemistry and in situ hybridization were utilized to examine the localization and expression of proteins involved in reabsorption and secretion of ions and fluid. Further, in vivo calcium imaging was employed to investigate cellular function. Based on the protein expression profile and functional data, marked differences between the IDs and striated ducts were observed. Specifically, the ID cells express proteins native to the secretory acinar cells while lacking proteins specifically expressed in the striated ducts. Further, the ID and striated duct cells display different calcium signalling characteristics, with the IDs responding to a neural stimulus in a manner similar to the acinar cells. Overall, our data suggest that the IDs have a distinct role in the secretory process, separate from the reabsorptive striated ducts. Instead, based on our evidence, the IDs express proteins found in secretory cells, generate calcium signals in a manner similar to acinar cells, and, therefore, are likely secretory cells. KEY POINTS: Current studies examining salivary intercalated duct cells are limited, with minimal documentation of the ion transport machinery and the overall role of the cells in fluid generation. Salivary intercalated duct cells are presumed to function in the same manner as other duct cells, reclaiming ions, maintaining fluid volume and delivering the final saliva to the oral cavity. Here we systematically examine the structure and function of the salivary intercalated duct cells using immunohistochemistry, in situ hybridization and by monitoring in vivo Ca2+ dynamics. Structural data revealed that the intercalated duct cells lack proteins vital for reabsorption and express proteins necessary for secretion. Ca2+ dynamics in the intercalated duct cells were consistent with those observed in secretory cells and resulted from GPCR-mediated IP3 production.
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Affiliation(s)
- Amanda M Wahl
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
| | - Takahiro Takano
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
| | - Shan Su
- Department of Mathematics, University of Auckland, Auckland, New Zealand
| | | | - Paola Perez
- Salivary Disorders Unit, NIDCR, Bethesda, MD, USA
| | - James Sneyd
- Department of Mathematics, University of Auckland, Auckland, New Zealand
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
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3
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Kim YJ. Xerostomia and Its Cellular Targets. Int J Mol Sci 2023; 24:ijms24065358. [PMID: 36982432 PMCID: PMC10049126 DOI: 10.3390/ijms24065358] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/26/2023] [Accepted: 03/02/2023] [Indexed: 03/14/2023] Open
Abstract
Xerostomia, the subjective feeling of a dry mouth associated with dysfunction of the salivary glands, is mainly caused by radiation and chemotherapy, various systemic and autoimmune diseases, and drugs. As saliva plays numerous essential roles in oral and systemic health, xerostomia significantly reduces quality of life, but its prevalence is increasing. Salivation mainly depends on parasympathetic and sympathetic nerves, and the salivary glands responsible for this secretion move fluid unidirectionally through structural features such as the polarity of acinar cells. Saliva secretion is initiated by the binding of released neurotransmitters from nerves to specific G-protein-coupled receptors (GPCRs) on acinar cells. This signal induces two intracellular calcium (Ca2+) pathways (Ca2+ release from the endoplasmic reticulum and Ca2+ influx across the plasma membrane), and this increased intracellular Ca2+ concentration ([Ca2+]i) causes the translocation of the water channel aquaporin 5 (AQP5) to the apical membrane. Consequently, the GPCR-mediated increased [Ca2+]i in acinar cells promotes saliva secretion, and this saliva moves into the oral cavity through the ducts. In this review, we seek to elucidate the potential of GPCRs, the inositol 1,4,5-trisphosphate receptor (IP3R), store-operated Ca2+ entry (SOCE), and AQP5, which are essential for salivation, as cellular targets in the etiology of xerostomia.
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Affiliation(s)
- Yoon-Jung Kim
- Department of Physiology and Neuroscience, Dental Research Institute, Seoul National University School of Dentistry, Seoul 03080, Republic of Korea
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4
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Supriya S, Ushikoshi-Nakayama R, Yamazaki T, Omagari D, Aota K, Inoue H, Matsumoto N, Saito I. Effects of polyphenols in non-centrifugal cane sugar on saliva secretion: in vitro and in vivo experiments and a randomized controlled trial. J Clin Biochem Nutr 2023; 72:171-182. [PMID: 36936876 PMCID: PMC10017321 DOI: 10.3164/jcbn.22-114] [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: 10/15/2022] [Accepted: 11/06/2022] [Indexed: 12/28/2022] Open
Abstract
This study examined the bioactivities and mechanisms of the non-centrifugal cane sugar polyphenols saponarin, schaftoside, and isoschaftoside in the salivary gland and their effects on salivation. In acute isolated C57BL/6N mouse submandibular gland cells, these polyphenols led to a higher increase in intracellular calcium after stimulation with the muscarinic agonist carbachol. Stimulation of these cells with polyphenols enhanced ATP production, aquaporin-5 translocation to the plasma membrane and eliminated intracellular reactive oxygen species generated by H2O2. In addition, phosphorylation of endothelial nitric oxide synthase and increased nitric oxide production in vascular endothelial cells were observed. In vivo administration of these polyphenols to C57BL/6N male mice resulted in significantly increased blood flow (saponarin, p = 0.040; isoschaftoside, p = 0.010) and salivation (saponarin, p = 0.031). A randomized controlled trial showed that intake of non-centrifugal cane sugar significantly increased saliva secretion compared with placebo (p = 0.003). These data suggest that non-centrifugal cane sugar polyphenols affect several pathways that support salivation and increase saliva secretion by enhancing vasodilation. Hence, non-centrifugal cane sugar polyphenols can be expected to maintain saliva secretion and improve reduced saliva flow.
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Affiliation(s)
- Shakya Supriya
- Department of Pathology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan
| | - Ryoko Ushikoshi-Nakayama
- Department of Pathology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan
| | - Tomoe Yamazaki
- Department of Pathology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan
| | - Daisuke Omagari
- Department of Pathology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan
| | - Keiko Aota
- Department of Oral Medicine, Tokushima University Graduate School of Biomedical Sciences, 3-18-15 Kuramoto-cho, Tokushima 770-8504, Japan
| | - Hiroko Inoue
- Department of Pharmaceutical Sciences, Nihon Pharmaceutical University, 10281 Komuro, Ina-machi, Kitaadachi-gun, Saitama 362-0806, Japan
| | - Naoyuki Matsumoto
- Department of Pathology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan
| | - Ichiro Saito
- Department of Pathology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan
- To whom correspondence should be addressed. E-mail:
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Takano T, Yule DI. In vivo Ca 2+ Imaging in Mouse Salivary Glands. Bio Protoc 2022; 12:e4380. [PMID: 35530515 PMCID: PMC9018428 DOI: 10.21769/bioprotoc.4380] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 12/03/2021] [Accepted: 03/01/2022] [Indexed: 12/29/2022] Open
Abstract
Changes in intracellular calcium drive exocrine cell activity. In the salivary gland, acetylcholine released from parasympathetic neurons mobilizes endoplasmic reticulum calcium stores in acinar cells, which consequently initiates saliva secretion. However, our understanding of the signaling cascade is mainly based on ex vivo studies performed in enzymatically isolated cells. The dissociation process likely disrupts the extracellular matrix, removes neurons as the source of signal input, and disturbs the integrity of tight and gap junctional acinar connections. These alterations may affect the spatiotemporal properties of calcium signaling events. In vivo observations of calcium signals, where tissue organization is intact, are therefore important to establish the characteristics of physiological calcium signals that are crucial for the stimulation of fluid secretion. Here, we present a detailed protocol for in vivo imaging of calcium signaling events, following nervous stimulation by multi-photon microscopy in mouse salivary gland acinar cells, expressing the genetically encoded calcium indicator GCamp6F.
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Affiliation(s)
- Takahiro Takano
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
| | - David I. Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
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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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7
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Bovell DL. The evolution of eccrine sweat gland research towards developing a model for human sweat gland function. Exp Dermatol 2019; 27:544-550. [PMID: 29626846 DOI: 10.1111/exd.13556] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/02/2018] [Indexed: 12/30/2022]
Abstract
For several decades now, researchers, professional bodies, governments, and journals such as the journal of Experimental Dermatology have worked to reduce the number of animals used in experimentation. This review centres on investigations into how human sweat glands produce sweat and how that research has evolved over the years. It is hoped that this review will show that as methodologies advanced, sweat gland research has come to rely less and less on a variety of animal models as investigative tools and information is being primarily obtained through human and mouse material, with a view to further reductions in using animal models.
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Affiliation(s)
- Douglas L Bovell
- Department of Medical Education, Weill Cornell Medicine - Qatar, Doha, Qatar
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8
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Contribution of HIV Infection, AIDS, and Antiretroviral Therapy to Exocrine Pathogenesis in Salivary and Lacrimal Glands. Int J Mol Sci 2018; 19:ijms19092747. [PMID: 30217034 PMCID: PMC6164028 DOI: 10.3390/ijms19092747] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/04/2018] [Accepted: 09/07/2018] [Indexed: 02/07/2023] Open
Abstract
The structure and function of exocrine glands are negatively affected by human immunodeficiency virus (HIV) infection and its co-morbidities, including innate and adaptive immune responses. At the same time, exocrine function may also be influenced by pharmacotherapies directed at the infectious agents. Here, we briefly review the role of the salivary glands and lacrimal glands in normal physiology and exocrine pathogenesis within the context of HIV infection and acquired immune deficiency syndrome (AIDS), including the contribution of antiretroviral therapies on both. Subsequently, we discuss the impact of HIV infection and the types of antiretroviral therapy on disease management and therapy development efforts.
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9
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TRP Channel Involvement in Salivary Glands-Some Good, Some Bad. Cells 2018; 7:cells7070074. [PMID: 29997338 PMCID: PMC6070825 DOI: 10.3390/cells7070074] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/06/2018] [Accepted: 07/08/2018] [Indexed: 12/26/2022] Open
Abstract
Salivary glands secrete saliva, a mixture of proteins and fluids, which plays an extremely important role in the maintenance of oral health. Loss of salivary secretion causes a dry mouth condition, xerostomia, which has numerous deleterious consequences including opportunistic infections within the oral cavity, difficulties in eating and swallowing food, and problems with speech. Secretion of fluid by salivary glands is stimulated by activation of specific receptors on acinar cell plasma membrane and is mediated by an increase in cytosolic [Ca2+] ([Ca2+]i). The increase in [Ca2+]i regulates a number of ion channels and transporters that are required for establishing an osmotic gradient that drives water flow via aquaporin water channels in the apical membrane. The Store-Operated Ca2+ Entry (SOCE) mechanism, which is regulated in response to depletion of ER-Ca2+, determines the sustained [Ca2+]i increase required for prolonged fluid secretion. Core components of SOCE in salivary gland acinar cells are Orai1 and STIM1. In addition, TRPC1 is a major and non-redundant contributor to SOCE and fluid secretion in salivary gland acinar and ductal cells. Other TRP channels that contribute to salivary flow are TRPC3 and TRPV4, while presence of others, including TRPM8, TRPA1, TRPV1, and TRPV3, have been identified in the gland. Loss of salivary gland function leads to dry mouth conditions, or xerostomia, which is clinically seen in patients who have undergone radiation treatment for head-and-neck cancers, and those with the autoimmune exocrinopathy, Sjögren’s syndrome (pSS). TRPM2 is a unique TRP channel that acts as a sensor for intracellular ROS. We will discuss recent studies reported by us that demonstrate a key role for TRPM2 in radiation-induced salivary gland dysfunction. Further, there is increasing evidence that TRPM2 might be involved in inflammatory processes. These interesting findings point to the possible involvement of TRPM2 in Sjögren’s Syndrome, although further studies will be required to identify the exact role of TRPM2 in this disease.
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10
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Trampert DC, Nathanson MH. Regulation of bile secretion by calcium signaling in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1761-1770. [PMID: 29787781 DOI: 10.1016/j.bbamcr.2018.05.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/12/2018] [Accepted: 05/16/2018] [Indexed: 12/15/2022]
Abstract
Calcium (Ca2+) signaling controls secretion in many types of cells and tissues. In the liver, Ca2+ regulates secretion in both hepatocytes, which are responsible for primary formation of bile, and cholangiocytes, which line the biliary tree and further condition the bile before it is secreted. Cholestatic liver diseases, which are characterized by impaired bile secretion, may result from impaired Ca2+ signaling mechanisms in either hepatocytes or cholangiocytes. This review will discuss the Ca2+ signaling machinery and mechanisms responsible for regulation of secretion in both hepatocytes and cholangiocytes, and the pathophysiological changes in Ca2+ signaling that can occur in each of these cell types to result in cholestasis.
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Affiliation(s)
- David C Trampert
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8019, USA
| | - Michael H Nathanson
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8019, USA.
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11
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12
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Qian X, Shi X, Wang H. Effect of paeoniflorin on the calcium ion concentration in salivary gland cells using confocal laser scanning microscopy. Am J Transl Res 2016; 8:3678-3688. [PMID: 27725850 PMCID: PMC5040668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 07/09/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To investigate the effects of paeoniflorin, the main monomer component of Jinxueyuan granules, on the Ca2+ concentrations in salivary gland cells to further explore the salivation-promoting mechanism and effective monomer components of Jinxueyuan granules. METHODS The salivary gland cells of suckling rats were cultured in vitro and loaded with a Fluo-3AM fluorescent probe, and changes in the intracellular Ca2+ concentrations were observed using a confocal laser scanning microscope. RESULTS No significant changes in the intracellular Ca2+ concentrations were demonstrated (P>0.05) in the paeoniflorin-free Hank's media treatment group or in the higher-dose paeoniflorin (10-2 mol/L) Hank's media treatment group; however, a significant increase in the intracellular Ca2+ concentration in the lower-dose paeoniflorin (10-4 mol/L) treatment group was observed (P=0.001). Further study showed that treatment with the calcium channel blocker verapamil hydrochloride or with Ca2+-free D-Hank's media did not block the paeoniflorin-induced (10-4 mol/L) increase in intracellular Ca2+ (P<0.05). CONCLUSION Paeoniflorin promotes the release of endogenous calcium to upregulate the intracellular Ca2+ concentration. Further studies should be performed to investigate the association between paeoniflorin and the Ca2+ concentration in salivary gland cells and to elucidate the corresponding functional pathways.
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Affiliation(s)
- Xian Qian
- Department of Rheumatism, The Affiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029, China
| | - Xiaolu Shi
- Department of Rheumatism, The Affiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029, China
| | - Hongyi Wang
- Department of Pharmacology, Nanjing Medical UniversityNanjing 210029, China
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A putative mitochondrial calcium uniporter in A. fumigatus contributes to mitochondrial Ca(2+) homeostasis and stress responses. Fungal Genet Biol 2016; 94:15-22. [PMID: 27378202 DOI: 10.1016/j.fgb.2016.07.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 06/14/2016] [Accepted: 07/01/2016] [Indexed: 12/30/2022]
Abstract
Ca(2+) uptake into mitochondria plays a central role in cell physiology by stimulating ATP production, shaping cytosolic Ca(2+) transients and regulating cell survival or death. Although this system has been studied extensively in mammalian cells, the physiological implications of Ca(2+) uptake into mitochondria in fungal cells are still unknown. In this study, a bi-directional best-hit BLASTP search revealed that the genome of Aspergillus fumigatus encodes a homolog of a putative mitochondrial Ca(2+) uniporter (MCU) and a mitochondrial carrier protein AGC1/MICU1 homolog. Both putative homologs are mitochondrially localized and required for the response to azole and oxidative stress such that the loss of either McuA or AgcA results in reduced susceptibility to azole and oxidative stress, suggesting a role in environmental stress adaptation. Overexpressing mcuA restores the azole-resistance phenotype of the ΔagcA strain to wild-type levels, but not vice versa, indicating McuA plays a dominant role during these stress responses. Using a mitochondrially targeted version of the calcium-sensitive photoprotein aequorin, we found that only mcuA deletion leads to dysfunctional [Ca(2+)]mt and [Ca(2+)]c homeostasis, suggesting that McuA, but not AgcA, contributes to Ca(2+) uptake into mitochondria. Further point-mutation experiments combined with extracellular Ca(2+) chelator treatment verified that two predicted Ca(2+)-binding sites in McuA are required for Ca(2+) uptake into mitochondria and stress responses through the regulation of [Ca(2+)]c homeostasis.
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14
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Ambudkar IS. Calcium signalling in salivary gland physiology and dysfunction. J Physiol 2016; 594:2813-24. [PMID: 26592972 PMCID: PMC4887685 DOI: 10.1113/jp271143] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 10/31/2015] [Indexed: 01/29/2023] Open
Abstract
Studies over the past four decades have established that Ca(2+) is a critical factor in control of salivary gland function and have led to identification of the critical components of this process. The major ion transport mechanisms and ion channels that are involved in fluid secretion have also been established. The key event in activation of fluid secretion is an increase in [Ca(2+) ]i triggered by inositol 1,4,5-trisphosphate (IP3 )-induced release of Ca(2+) from ER via the IP3 receptor (IP3 R). IP3 Rs determine the site of initiation and the pattern of the [Ca(2+) ]i signal in the cell. However, Ca(2+) entry into the cell is required to sustain the elevation of [Ca(2+) ]i and fluid secretion and is mediated by the store-operated Ca(2+) entry (SOCE) mechanism. Orai1, TRPC1, TRPC3 and STIM1 have been identified as critical components of SOCE in these cells. Cells finely tune the generation and amplification of [Ca(2+) ]i signals for regulation of cell function. An important emerging area is the concept that unregulated [Ca(2+) ]i signals in cells can directly cause cell damage, dysfunction and disease. Alternatively, aberrant [Ca(2+) ]i signals can also amplify and increase the rates of cell damage. Such defects in Ca(2+) signalling have been described in salivary glands in conjunction with radiation-induced loss of salivary gland function as well as in the salivary defects associated with the autoimmune exocrinopathy Sjögren's syndrome. Such defects have been associated with altered function or expression of key Ca(2+) signalling components, such as STIM proteins and TRP channels. These studies offer new avenues for examining the mechanisms underlying the disease and development of novel clinical targets and therapeutic strategies.
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Affiliation(s)
- Indu S Ambudkar
- Secretory Physiology Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, MD, 20892, USA
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15
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Villa A, Wolff A, Narayana N, Dawes C, Aframian DJ, Lynge Pedersen AM, Vissink A, Aliko A, Sia YW, Joshi RK, McGowan R, Jensen SB, Kerr AR, Ekström J, Proctor G. World Workshop on Oral Medicine VI: a systematic review of medication-induced salivary gland dysfunction. Oral Dis 2016; 22:365-82. [PMID: 26602059 DOI: 10.1111/odi.12402] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 11/11/2015] [Accepted: 11/14/2015] [Indexed: 12/11/2022]
Abstract
The aim of this paper was to perform a systematic review of the pathogenesis of medication-induced salivary gland dysfunction (MISGD). Review of the identified papers was based on the standards regarding the methodology for systematic reviews set forth by the World Workshop on Oral Medicine IV and the PRISMA statement. Eligible papers were assessed for both the degree and strength of relevance to the pathogenesis of MISGD as well as on the appropriateness of the study design and sample size. A total of 99 papers were retained for the final analysis. MISGD in human studies was generally reported as xerostomia (the sensation of oral dryness) without measurements of salivary secretion rate. Medications may act on the central nervous system (CNS) and/or at the neuroglandular junction on muscarinic, α-and β-adrenergic receptors and certain peptidergic receptors. The types of medications that were most commonly implicated for inducing salivary gland dysfunction were those acting on the nervous, cardiovascular, genitourinary, musculoskeletal, respiratory, and alimentary systems. Although many medications may affect the salivary flow rate and composition, most of the studies considered only xerostomia. Thus, further human studies are necessary to improve our understanding of the association between MISGD and the underlying pathophysiology.
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Affiliation(s)
- A Villa
- Division of Oral Medicine and Dentistry, Brigham and Women's Hospital, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - A Wolff
- Tel-Aviv Sourasky Medical Center and Saliwell Ltd., Harutzim, Israel
| | - N Narayana
- Department of Oral Biology, UNMC College of Dentistry, Lincoln, NE, USA
| | - C Dawes
- Department of Oral Biology, University of Manitoba, Winnipeg, MB, Canada
| | | | - A M Lynge Pedersen
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - A Vissink
- University of Groningen and University Medical Center Groningen, Groningen, The Netherlands
| | - A Aliko
- Faculty of Dental Medicine, University of Medicine, Tirana, Albania.,Broegelmann Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Y W Sia
- McGill University, Montreal, QC, Canada
| | - R K Joshi
- DAPMRV Dental College, Bangalore, India
| | - R McGowan
- New York University College of Dentistry, New York, NY, USA
| | - S B Jensen
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - A R Kerr
- New York University College of Dentistry, New York, NY, USA
| | - J Ekström
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - G Proctor
- Division of Mucosal & Salivary Biology, Dental Institute, King's College London, London, UK
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Bhattacharya S, Imbery JF, Ampem PT, Giovannucci DR. Crosstalk between purinergic receptors and canonical signaling pathways in the mouse salivary gland. Cell Calcium 2015; 58:589-97. [PMID: 26443524 DOI: 10.1016/j.ceca.2015.09.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 09/22/2015] [Accepted: 09/25/2015] [Indexed: 01/21/2023]
Abstract
Isolated clusters of mouse parotid acinar cells in combination with live cell imaging were used to explore the crosstalk in molecular signaling between purinergic, cholinergic and adrenergic pathways that integrate to control fluid and protein secretion. This crosstalk was manifested by (1) β-adrenergic receptor activation and amplification of P2X4R evoked Ca(2+) signals, (2) β-adrenergic-induced amplification of P2X7R-evoked Ca(2+) signals and (3) muscarinic receptor induced activation of P2X7Rs via exocytotic activity. The findings from our study reveal that purinoceptor-mediated Ca(2+) signaling is modulated by crosstalk with canonical signaling pathways in parotid acinar cells. Integration of these signals are likely important for dynamic control of saliva secretion to match physiological demand in the parotid gland.
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Affiliation(s)
- Sumit Bhattacharya
- Department of Neurosciences, University of Toledo Medical Center, 3000 Arlington Avenue, Toledo, OH 43614, USA
| | - John F Imbery
- Department of Neurosciences, University of Toledo Medical Center, 3000 Arlington Avenue, Toledo, OH 43614, USA
| | - Prince Tuffour Ampem
- Department of Neurosciences, University of Toledo Medical Center, 3000 Arlington Avenue, Toledo, OH 43614, USA
| | - David R Giovannucci
- Department of Neurosciences, University of Toledo Medical Center, 3000 Arlington Avenue, Toledo, OH 43614, USA.
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IP3R deficit underlies loss of salivary fluid secretion in Sjögren's Syndrome. Sci Rep 2015; 5:13953. [PMID: 26365984 PMCID: PMC4568516 DOI: 10.1038/srep13953] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/12/2015] [Indexed: 12/17/2022] Open
Abstract
The autoimmune exocrinopathy, Sjögren’s syndrome (SS), is associated with secretory defects in patients, including individuals with mild lymphocytic infiltration and minimal glandular damage. The mechanism(s) underlying the secretory dysfunction is not known. We have used minor salivary gland biopsies from SS patients and healthy individuals to assess acinar cell function in morphologically intact glandular areas. We report that agonist-regulated intracellular Ca2+ release, critically required for Ca2+ entry and fluid secretion, is defective in acini from SS patients. Importantly, these acini displayed reduction in IP3R2 and IP3R3, but not AQP5 or STIM1. Similar decreases in IP3R and carbachol (CCh)-stimulated [Ca2+]i elevation were detected in acinar cells from lymphotoxin-alpha (LTα) transgenic (TG) mice, a model for (SS). Treatment of salivary glands from healthy individuals with LT α, a cytokine linked to disease progression in SS and IL14α mice, reduced Ca2+ signaling. Together, our findings reveal novel IP3R deficits in acinar cells that underlie secretory dysfunction in SS patients.
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Majewski L, Kuznicki J. SOCE in neurons: Signaling or just refilling? BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1940-52. [DOI: 10.1016/j.bbamcr.2015.01.019] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 01/22/2015] [Accepted: 01/26/2015] [Indexed: 01/14/2023]
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Southward K. A hypothetical role for vitamin K2 in the endocrine and exocrine aspects of dental caries. Med Hypotheses 2015; 84:276-80. [DOI: 10.1016/j.mehy.2015.01.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 01/11/2015] [Indexed: 12/27/2022]
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20
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Lee K, Choi S, Choi LM, Lee J, Kim JH, Chung G, Lee G, Choi SY, Park K. Desipramine inhibits salivary Ca(2+) signaling and aquaporin translocation. Oral Dis 2015; 21:530-5. [PMID: 25639149 DOI: 10.1111/odi.12317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 01/19/2015] [Accepted: 01/20/2015] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Desipramine is a tricyclic antidepressant with a negative side effect of dry mouth. The Na(+) /H(+) exchanger was suggested to be a target of desipramine in salivary gland cells. However, it is unclear whether desipramine has other targets in the salivary secretion pathway. Here, we studied the effect of desipramine on salivary Ca(2+) signaling. MATERIALS AND METHODS Cytosolic free Ca(2+) concentration ([Ca(2+) ]i ) was determined with the fluorescent Ca(2+) indicator fura-2/AM. Aquaporin translocation was analyzed by Western blotting and immunocytochemistry of confocal microscopy. RESULTS Desipramine inhibited the carbachol- and histamine-mediated increase in cytosolic Ca(2+) ([Ca(2+) ]i ) in a concentration-dependent manner. However, desipramine did not affect increases in [Ca(2+) ]i mediated by extracellular ATP, sphingosine-1-phosphate, or thapsigargin. The adrenergic receptor blockers prazosin and propranolol did not reverse the desipramine-mediated inhibition of carbachol- and histamine-induced increases in [Ca(2+) ]i . We also found that desipramine inhibits the increase in membrane aquaporin-5 level triggered by carbachol and histamine treatments. CONCLUSIONS These results imply that desipramine blocks muscarinic and histamine receptor-mediated Ca(2+) signaling and the subsequent translocation of aquaporin-5 in human salivary gland cells, suggesting a novel mechanism for the xerogenic effects of desipramine.
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Affiliation(s)
- K Lee
- Department of Physiology, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Korea
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21
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22
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Ambudkar IS. Ca²⁺ signaling and regulation of fluid secretion in salivary gland acinar cells. Cell Calcium 2014; 55:297-305. [PMID: 24646566 DOI: 10.1016/j.ceca.2014.02.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 02/10/2014] [Accepted: 02/11/2014] [Indexed: 01/04/2023]
Abstract
Neurotransmitter stimulation of plasma membrane receptors stimulates salivary gland fluid secretion via a complex process that is determined by coordinated temporal and spatial regulation of several Ca(2+) signaling processes as well as ion flux systems. Studies over the past four decades have demonstrated that Ca(2+) is a critical factor in the control of salivary gland function. Importantly, critical components of this process have now been identified, including plasma membrane receptors, calcium channels, and regulatory proteins. The key event in activation of fluid secretion is an increase in intracellular [Ca(2+)] ([Ca(2+)]i) triggered by IP3-induced release of Ca(2+) from ER via the IP3R. This increase regulates the ion fluxes required to drive vectorial fluid secretion. IP3Rs determine the site of initiation and the pattern of [Ca(2+)]i signal in the cell. However, Ca(2+) entry into the cell is required to sustain the elevation of [Ca(2+)]i and fluid secretion. This Ca(2+) influx pathway, store-operated calcium influx pathway (SOCE), has been studied in great detail and the regulatory mechanisms as well as key molecular components have now been identified. Orai1, TRPC1, and STIM1 are critical components of SOCE and among these, Ca(2+) entry via TRPC1 is a major determinant of fluid secretion. The receptor-evoked Ca(2+) signal in salivary gland acinar cells is unique in that it starts at the apical pole and then rapidly increases across the cell. The basis for the polarized Ca(2+) signal can be ascribed to the polarized arrangement of the Ca(2+) channels, transporters, and signaling proteins. Distinct localization of these proteins in the cell suggests compartmentalization of Ca(2+) signals during regulation of fluid secretion. This chapter will discuss new concepts and findings regarding the polarization and control of Ca(2+) signals in the regulation of fluid secretion.
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Affiliation(s)
- Indu S Ambudkar
- Secretory Physiology Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892, United States.
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23
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Saul S, Stanisz H, Backes CS, Schwarz EC, Hoth M. How ORAI and TRP channels interfere with each other: interaction models and examples from the immune system and the skin. Eur J Pharmacol 2013; 739:49-59. [PMID: 24291108 DOI: 10.1016/j.ejphar.2013.10.071] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 10/08/2013] [Accepted: 10/17/2013] [Indexed: 11/16/2022]
Abstract
Four types of Ca(2+) selective ion channels are known, ten voltage gated Ca(2+) (CaV) channels, four CatSper channels, three store operated CRAC channels (ORAI channels) and at least two members of the TRPV subfamily (TRPV5, TRPV6). Some of the other TRP channels also show some Ca(2+) selectivity like certain splice variants of TRPM3. In addition to Ca(2+) selective channels, various cation channels play an important role for Ca(2+) entry and furthermore, they may also regulate Ca(2+) entry through other channels by modulating the membrane potential or other means as outlined in this review. Of the different types of cation channels, TRP channels form one of the most prominent families of non-selective cation channels with functional relevance in electrically non-excitable and electrically excitable cell types. Among these, the seven channels of the TRPC subfamily are rather non-selective with very modest Ca(2+) selectivity, whereas in the other subfamilies, cation selectivity ranges from monovalent selectivity (i.e. TRPM4, TRPM5) to divalent selectivity (i.e. TRPM6, TRPM7) or Ca(2+) selectivity (i.e. TRPV5, TRPV6). Rather than discussing the heavily reviewed individual functions of ORAI or TRP channels, we summarize data and present models how TRP and ORAI may functionally interact to guide cellular functions. We focus on T lymphocytes representing a more ORAI-dominated tissue and skin as model system in which both ORAI and TRP channel have been reported to control relevant functions. We present several interaction models how ORAI and TRP may interfere with each other's function.
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Affiliation(s)
- Stephanie Saul
- Department of Biophysics, School of Medicine, Saarland University, Homburg, Germany
| | - Hedwig Stanisz
- Department of Dermatology, School of Medicine, Saarland University, Homburg, Germany
| | - Christian S Backes
- Department of Biophysics, School of Medicine, Saarland University, Homburg, Germany
| | - Eva C Schwarz
- Department of Biophysics, School of Medicine, Saarland University, Homburg, Germany
| | - Markus Hoth
- Department of Biophysics, School of Medicine, Saarland University, Homburg, Germany.
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24
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Immunolocalization and distribution of functional temperature-sensitive TRP channels in salivary glands. Cell Tissue Res 2013; 354:507-19. [DOI: 10.1007/s00441-013-1691-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 06/26/2013] [Indexed: 01/27/2023]
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25
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Pradhan-Bhatt S, Harrington DA, Duncan RL, Jia X, Witt RL, Farach-Carson MC. Implantable three-dimensional salivary spheroid assemblies demonstrate fluid and protein secretory responses to neurotransmitters. Tissue Eng Part A 2013; 19:1610-20. [PMID: 23442148 DOI: 10.1089/ten.tea.2012.0301] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Radiation treatment in patients with head and neck tumors commonly results in hyposalivation and xerostomia due to the loss of fluid-secreting salivary acinar cells. Patients develop susceptibility to oral infections, dental caries, impaired speech and swallowing, reducing the quality of life. Clinical management is largely unsatisfactory. The development of a tissue-engineered, implantable salivary gland will greatly benefit patients suffering from xerostomia. This report compares the ability of a 2.5-dimensional (2.5D) and a three-dimensional (3D) hyaluronic acid (HA)-based culture system to support functional salivary units capable of producing fluid and phenotypic proteins. Parotid cells seeded on 2.5D, as well as those encapsulated in 3D HA hydrogels, self-assembled into acini-like structures and expressed functional neurotransmitter receptors. Structures in 3D hydrogels merged to form organized 50 μm spheroids that could be maintained in culture for over 100 days and merged to form structures over 500 μm in size. Treatment of acini-like structures with the β-adrenergic agonists norepinephrine or isoproterenol increased granule production and α-amylase staining in treated structures, demonstrating regain of protein secretion. Upon treatment with the M3 muscarinic agonist acetylcholine, acini-like structures activated the fluid production pathway by increasing intracellular calcium levels. The increase in intracellular calcium seen in structures in the 3D hydrogel culture system was more robust and prolonged than that in 2.5D. To compare the long-term survival and retention of acini-like structures in vivo, cell-seeded 2.5D and 3D hydrogels were implanted into an athymic rat model. Cells in 2.5D failed to maintain organized acini-like structures and dispersed in the surrounding tissue. Encapsulated cells in 3D retained their spheroid structure and structural integrity, along with the salivary biomarkers and maintained viability for over 3 weeks in vivo. This report identifies a novel hydrogel culture system capable of creating and maintaining functional 3D salivary spheroid structures for long periods in vitro that regain both fluid and protein secreting functions and are suitable for tissue restoration.
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Affiliation(s)
- Swati Pradhan-Bhatt
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
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26
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Castro I, Sepúlveda D, Cortés J, Quest A, Barrera M, Bahamondes V, Aguilera S, Urzúa U, Alliende C, Molina C, González S, Hermoso M, Leyton C, González M. Oral dryness in Sjögren's syndrome patients. Not just a question of water. Autoimmun Rev 2013. [DOI: 10.1016/j.autrev.2012.10.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Zhang Y, Catalán MA, Melvin JE. TRPV4 activation in mouse submandibular gland modulates Ca2+ influx and salivation. Am J Physiol Gastrointest Liver Physiol 2012; 303:G1365-72. [PMID: 23086916 PMCID: PMC3532547 DOI: 10.1152/ajpgi.00366.2012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Transient receptor potential vanilloid subtype 4 (TRPV4) is a ligand-gated nonselective cation channel that participates in the transduction of mechanical and osmotic stimuli in different tissues. TRPV4 is activated by endogenous arachidonic acid metabolites, 4α-phorbol-12,13 didecanoate, GSK1016790A, moderate heat, and mechanical stress. TRPV4 is expressed in the salivary glands, but its expression pattern and function are poorly understood. The aim of this study was to evaluate the functional role of TRPV4 channels in the mouse submandibular gland. Using RT-PCR and Western blot analysis, we detected expression of TRPV4 message and protein, respectively, in the submandibular gland. Immunolocalization studies showed that TRPV4 targeted to the basolateral membrane of mouse submandibular gland acinar cells. Pharmacological TRPV4 activation using the selective agonist GSK1016790A caused Ca(2+) influx in isolated acinar cells in a basal-to-apical wave. Consistent with these observations, GSK1016790A elicited salivation in the perfused submandibular gland that was dependent on extracellular Ca(2+). In summary, we report that activation of TRPV4 channels induced Ca(2+) influx and salivation and, thus, may contribute a novel nonadrenergic, noncholinergic secretion pathway in the mouse submandibular gland.
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Affiliation(s)
- Yan Zhang
- Secretory Mechanisms and Dysfunction Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Marcelo A. Catalán
- Secretory Mechanisms and Dysfunction Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - James E. Melvin
- Secretory Mechanisms and Dysfunction Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
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28
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Mateescu RG, Garmyn AJ, Tait RG, Duan Q, Liu Q, Mayes MS, Garrick DJ, Van Eenennaam AL, Vanoverbeke DL, Hilton GG, Beitz DC, Reecy JM. Genetic parameters for concentrations of minerals in longissimus muscle and their associations with palatability traits in Angus cattle. J Anim Sci 2012; 91:1067-75. [PMID: 23230113 DOI: 10.2527/jas.2012-5744] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The objective of this study was to estimate genetic parameters for concentrations of minerals in LM and to evaluate their associations with beef palatability traits. Samples of LM from 2,285 Angus cattle were obtained and fabricated into steaks for analysis of mineral concentrations and for trained sensory panel assessments. Nine minerals, including calcium, copper, iron, magnesium, manganese, phosphorus, potassium, sodium, and zinc, were quantified. Restricted maximum likelihood procedures were used to obtain estimates of variance and covariance components under a multiple-trait animal model. Estimates of heritability for mineral concentrations in LM varied from 0.01 to 0.54. Iron and sodium were highly and moderately heritable, respectively, whereas the other minerals were lowly heritable except for calcium, copper, and manganese, which exhibited no genetic variation. Strong positive genetic correlations existed between iron and zinc (0.49, P < 0.05), between magnesium and phosphorus (0.88, P < 0.05), between magnesium and sodium (0.68, P < 0.05), and between phosphorus and potassium (0.69, P < 0.05). Overall tenderness assessed by trained sensory panelists was positively associated with manganese, potassium, and sodium and negatively associated with phosphorus and zinc concentrations (P < 0.05). Juiciness assessed by trained sensory panelists was negatively associated with magnesium and positively associated with manganese and sodium concentrations (P < 0.05). Livery or metallic flavor was not associated with any of the minerals (P > 0.05). Beefy flavor was positively associated with calcium, iron, and zinc and negatively associated with sodium concentration, whereas a painty or fishy flavor was positively associated with sodium and negatively associated with calcium and potassium concentrations (P < 0.05). Beef is a major contributor of iron and zinc in the human diet, and these results demonstrate sufficient genetic variation for these traits to be improved through marker-assisted selection programs without compromising beef palatability.
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Affiliation(s)
- R G Mateescu
- Department of Animal Science, Oklahoma State University, Stillwater 74078, USA
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29
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Wang S, Cao J, Liu X, Hu H, Shi J, Zhang S, Keller NP, Lu L. Putative calcium channels CchA and MidA play the important roles in conidiation, hyphal polarity and cell wall components in Aspergillus nidulans. PLoS One 2012; 7:e46564. [PMID: 23071589 PMCID: PMC3470553 DOI: 10.1371/journal.pone.0046564] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 08/31/2012] [Indexed: 11/25/2022] Open
Abstract
Although the high affinity Ca2+ channel, Cch1, and its subunit Mid1 have been investigated and evaluated in yeast and some of filamentous fungi, little is known about the function of their homologs in the Aspergilli. Here, we have functionally characterized the yeast homologs, CchA and MidA, in Aspergillus nidulans using conditional and null deletion mutants. CchA and MidA not only have functional benefits of fast growth, which is consistent with Cch1 and Mid1 in yeast, but also have unique and complex roles in regulating conidiation, hyphal polarity and cell wall components in low-calcium environments. The defect of CchA or MidA resulted in a sharp reduction in the number of conidiospores, accompanied by abnormal metulae, and undeveloped-phialides at a higher density of inoculum. Most interestingly, these conidiation defects in mutants can, remarkably, be rescued either by extra-cellular Ca2+ in a calcineurin-dependent way or by osmotic stress in a calcineurin-independent way. Moreover, the fact that the phenotypic defects are not exacerbated by the presence of the double deletion, together with the Y2H assay, indicates that CchA and MidA may form a complex to function together. Our findings suggest that the high-affinity Ca2+ channel may represent a viable and completely unexplored avenue to reduce conidiation in the Aspergilli.
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Affiliation(s)
- Sha Wang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences; Nanjing Normal University, Nanjing, China
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Bhattacharya S, Verrill DS, Carbone KM, Brown S, Yule DI, Giovannucci DR. Distinct contributions by ionotropic purinoceptor subtypes to ATP-evoked calcium signals in mouse parotid acinar cells. J Physiol 2012; 590:2721-37. [PMID: 22451435 DOI: 10.1113/jphysiol.2012.228148] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
There is emerging consensus that P2X₄ and P2X₇ ionotropic purinoceptors (P2X₄R and P2X₇R) are critical players in regulating [Ca²⁺]i dynamics and fluid secretion in the salivary gland. In contrast, details regarding their compartmentalization and selective activation, contributions to the spatiotemporal properties of intracellular signals and roles in regulating protein exocytosis and ion channel activity have remained largely undefined. To address these concerns, we profiled mouse parotid acinar cells using live-cell imaging to follow the spatial and temporal features of ATP-evoked Ca²⁺ dynamics and exocytotic activity. Selective activation of P2X7Rs revealed an apical-to-basal [Ca²⁺]i signal that initiated at the sub-luminal border and propagated with a wave speed estimated at 17.3 ± 4.3 μm s⁻¹ (n =6). The evoked Ca²⁺ spike consisted of Ca²⁺ influx and Ca²⁺-induced Ca²⁺ release from intracellular Ca²⁺ channels. In contrast, selective activation of P2X₄Rs induced a Ca²⁺ signal that initiated basally and propagated toward the lumen with a wave speed of 4.3 ± 0.2 μm s⁻¹ (n =8) that was largely independent of intracellular Ca²⁺ channel blockade. Consistent with these observations, P2X₇R expression was enriched in the sub-luminal regions of acinar cells while P2X₄R appeared localized to basal areas. In addition, we showed that P2X₄R and P2X₇R activation evokes exocytosis in parotid acinar cells. Our studies also demonstrate that the P2X₄R-mediated [Ca²⁺]i rise and subsequent protein exocytosis was enhanced by ivermectin (IVR). Thus, in addition to furthering our understanding of salivary gland physiology, this study identifies P2X₄R as a potential target for treatment of salivary hypofunction diseases.
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Affiliation(s)
- Sumit Bhattacharya
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, USA
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31
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Park HS, Betzenhauser MJ, Zhang Y, Yule DI. Regulation of Ca²⁺ release through inositol 1,4,5-trisphosphate receptors by adenine nucleotides in parotid acinar cells. Am J Physiol Gastrointest Liver Physiol 2012; 302:G97-G104. [PMID: 21960523 PMCID: PMC3345966 DOI: 10.1152/ajpgi.00328.2011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Secretagogue-stimulated intracellular Ca(2+) signals are fundamentally important for initiating the secretion of the fluid and ion component of saliva from parotid acinar cells. The Ca(2+) signals have characteristic spatial and temporal characteristics, which are defined by the specific properties of Ca(2+) release mediated by inositol 1,4,5-trisphosphate receptors (InsP(3)R). In this study we have investigated the role of adenine nucleotides in modulating Ca(2+) release in mouse parotid acinar cells. In permeabilized cells, the Ca(2+) release rate induced by submaximal [InsP(3)] was increased by 5 mM ATP. Enhanced Ca(2+) release was not observed at saturating [InsP(3)]. The EC(50) for the augmented Ca(2+) release was ∼8 μM ATP. The effect was mimicked by nonhydrolysable ATP analogs. ADP and AMP also potentiated Ca(2+) release but were less potent than ATP. In acini isolated from InsP(3)R-2-null transgenic animals, the rate of Ca(2+) release was decreased under all conditions but now enhanced by ATP at all [InsP(3)]. In addition the EC(50) for ATP potentiation increased to ∼500 μM. These characteristics are consistent with the properties of the InsP(3)R-2 dominating the overall features of InsP(3)R-induced Ca(2+) release despite the expression of all isoforms. Finally, Ca(2+) signals were measured in intact parotid lobules by multiphoton microscopy. Consistent with the release data, carbachol-stimulated Ca(2+) signals were reduced in lobules exposed to experimental hypoxia compared with control lobules only at submaximal concentrations. Adenine nucleotide modulation of InsP(3)R in parotid acinar cells likely contributes to the properties of Ca(2+) signals in physiological and pathological conditions.
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Affiliation(s)
- Hyung Seo Park
- University of Rochester Medical Center, Department of Pharmacology and Physiology, University of Rochester, Rochester, New York
| | - Matthew J. Betzenhauser
- University of Rochester Medical Center, Department of Pharmacology and Physiology, University of Rochester, Rochester, New York
| | - Yu Zhang
- University of Rochester Medical Center, Department of Pharmacology and Physiology, University of Rochester, Rochester, New York
| | - David I. Yule
- University of Rochester Medical Center, Department of Pharmacology and Physiology, University of Rochester, Rochester, New York
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