1
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Bai Y, Zhang K, Cao X, Chen P. Aquaporins in lacrimal glands and their role in dry eye disease. Exp Eye Res 2023; 236:109676. [PMID: 37827442 DOI: 10.1016/j.exer.2023.109676] [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: 12/14/2022] [Revised: 10/05/2023] [Accepted: 10/09/2023] [Indexed: 10/14/2023]
Abstract
Aging is the most important known risk factor for dry eye is aging, which is associated with changes in the structure and function of the lacrimal gland (LG) and characterized by atrophy, duct blocking lymphocyte infiltration, and reduced protein secretion. Aquaporins (AQP) have been proposed as a potential producer of exocrine gland fluids since exocrine secretion depends on the mobility of water. Therefore, the main topics of this review will be the expression, localization, and function of AQPs in LG. In addition, we review the mechanisms of fluid transport in exocrine gland fluid secretion and discuss the potential role of AQPs in dry eye.
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Affiliation(s)
- Ying Bai
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China
| | - Kaier Zhang
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China
| | - Xin Cao
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China
| | - Peng Chen
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China; Clinical Laboratory, Qingdao Central Hospital, The Second Affiliated Hospital of Medical College of Qingdao University, Qingdao, 266042, Shandong Province, China.
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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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Pechlivanidou M, Xenou K, Tzanetakos D, Koutsos E, Stergiou C, Andreadou E, Voumvourakis K, Giannopoulos S, Kilidireas C, Tüzün E, Tsivgoulis G, Tzartos S, Tzartos J. Potential Role of Antibodies against Aquaporin-1 in Patients with Central Nervous System Demyelination. Int J Mol Sci 2023; 24:12982. [PMID: 37629163 PMCID: PMC10455752 DOI: 10.3390/ijms241612982] [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: 06/28/2023] [Revised: 08/09/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
Aquaporins (AQPs; AQP0-AQP12) are water channels expressed in many and diverse cell types, participating in various functions of cells, tissues, and systems, including the central nervous system (CNS). AQP dysfunction and autoimmunity to AQPs are implicated in several diseases. The best-known example of autoimmunity against AQPs concerns the antibodies to AQP4 which are involved in the pathogenesis of neuromyelitis optica spectrum disorder (NMOSD), an autoimmune astrocytopathy, causing also CNS demyelination. The present review focuses on the discovery and the potential role of antibodies against AQP1 in the CNS, and their potential involvement in the pathophysiology of NMOSD. We describe (a) the several techniques developed for the detection of the AQP1-antibodies, with emphasis on methods that specifically identify antibodies targeting the extracellular domain of AQP1, i.e., those of potential pathogenic role, and (b) the available evidence supporting the pathogenic relevance of AQP1-antibodies in the NMOSD phenotype.
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Affiliation(s)
- Maria Pechlivanidou
- Tzartos NeuroDiagnostics, 11523 Athens, Greece; (M.P.); (K.X.); (E.K.); (C.S.); (S.T.)
| | - Konstantina Xenou
- Tzartos NeuroDiagnostics, 11523 Athens, Greece; (M.P.); (K.X.); (E.K.); (C.S.); (S.T.)
| | - Dimitrios Tzanetakos
- Second Department of Neurology ‘’Attikon’’ University Hospital, School of Medicine, National & Kapodistrian University of Athens, 12462 Athens, Greece; (D.T.); (K.V.); (S.G.); (G.T.)
| | - Emmanuel Koutsos
- Tzartos NeuroDiagnostics, 11523 Athens, Greece; (M.P.); (K.X.); (E.K.); (C.S.); (S.T.)
| | - Christos Stergiou
- Tzartos NeuroDiagnostics, 11523 Athens, Greece; (M.P.); (K.X.); (E.K.); (C.S.); (S.T.)
| | - Elisabeth Andreadou
- First Department of Neurology, ‘’Aiginiteion’’ University Hospital, National and Kapodistrian University of Athens, 11528 Athens, Greece; (E.A.); (C.K.)
| | - Konstantinos Voumvourakis
- Second Department of Neurology ‘’Attikon’’ University Hospital, School of Medicine, National & Kapodistrian University of Athens, 12462 Athens, Greece; (D.T.); (K.V.); (S.G.); (G.T.)
| | - Sotirios Giannopoulos
- Second Department of Neurology ‘’Attikon’’ University Hospital, School of Medicine, National & Kapodistrian University of Athens, 12462 Athens, Greece; (D.T.); (K.V.); (S.G.); (G.T.)
| | - Constantinos Kilidireas
- First Department of Neurology, ‘’Aiginiteion’’ University Hospital, National and Kapodistrian University of Athens, 11528 Athens, Greece; (E.A.); (C.K.)
- Second Department of Neurology, Henry Dunant Hospital Center, 11526 Athens, Greece
| | - Erdem Tüzün
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, 34093 Istanbul, Turkey;
| | - Georgios Tsivgoulis
- Second Department of Neurology ‘’Attikon’’ University Hospital, School of Medicine, National & Kapodistrian University of Athens, 12462 Athens, Greece; (D.T.); (K.V.); (S.G.); (G.T.)
| | - Socrates Tzartos
- Tzartos NeuroDiagnostics, 11523 Athens, Greece; (M.P.); (K.X.); (E.K.); (C.S.); (S.T.)
- Department of Neurobiology, Hellenic Pasteur Institute, 11521 Athens, Greece
- Department of Pharmacy, University of Patras, 26504 Patras, Greece
| | - John Tzartos
- Second Department of Neurology ‘’Attikon’’ University Hospital, School of Medicine, National & Kapodistrian University of Athens, 12462 Athens, Greece; (D.T.); (K.V.); (S.G.); (G.T.)
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4
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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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5
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Sandhya P, Akaishi T, Fujihara K, Aoki M. A novel association of osmotic demyelination in Sjögren's syndrome prompts revisiting role of aquaporins in CNS demyelinating diseases: A literature review. Mult Scler Relat Disord 2023; 69:104466. [PMID: 36584554 DOI: 10.1016/j.msard.2022.104466] [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: 09/30/2022] [Revised: 11/21/2022] [Accepted: 12/10/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Primary Sjögren's syndrome (SS) is a chronic systemic autoimmune disease with varied neurological manifestations. SS is associated with anti-aquaporin-4 antibody (AQP4-IgG)-positive neuromyelitis optica spectrum disorder (NMOSD), a demyelinating autoimmune disorder of the central nervous system (CNS). Intriguingly, there are reports of osmotic demyelinating syndrome (ODS), a supposedly non-inflammatory disorder, in the context of SS and renal tubular acidosis (RTA), both of which are not yet established risk factors for ODS. METHODS A literature search was undertaken to identify case reports of ODS in patients with SS. Details of the clinical and laboratory features of these patients were compiled. Additionally, we searched for NMOSD in patients with SS. We looked for co-existing RTA in patients with SS-ODS as well as SS-NMOSD. We also screened for reports of ODS in RTA without underlying SS. RESULTS & DISCUSSION We identified 15 patients (all women, median age 40 years) with ODS in SS, and all of these patients had comorbid RTA. There were only three reported cases of ODS in RTA without underlying SS. We identified a total of 67 patients with SS-NMOSD, of whom only 3 (4.5%) had RTA. Hence, unlike NMOSD, the development of ODS in SS requires a prolonged osmotic or electrolyte abnormality caused by the comorbid RTA. The 15 patients with ODS and SS -RTA, showed heterogeneous clinical manifestations and outcomes. The most common symptom was quadriparesis, seen in 14 of the 15 patients. Eleven of the 15 patients had one of the following features, either alone or in combination: worsening of the sensorium, extensor plantar response, dysphagia/dysarthria, and facial palsy. The latter four manifestations were present at the onset in 7 patients and later in the course of the illness in the remaining 4 patients. Ocular palsy was seen in only four of the 15 patients and was a late manifestation. One patient who had extensive long-segment myelitis and subsequent ODS died, but most patients recovered without significant sequelae. None had hyponatremia, while all patients had hypokalemia and/or hypernatremia. Hypokalemia causing nephrogenic diabetes insipidus (NDI) followed by rapid rise in sodium and the resultant osmotic stress could potentially explain the occurrence of ODS in SS-RTA. Aquaporin (AQP) in astrocytes is implicated in ODS, and renal AQP is downregulated in NDI. Antibodies against AQPs are present in some patients with SS. Defective AQP is therefore a common link underlying all the connected diseases, namely SS, NDI, and ODS, raising the possibility of immune-mediated AQP dysfunction in the pathogenesis. CONCLUSION The hitherto unreported association between SS-RTA and ODS may implicate SS and/or RTA in the development of ODS. In the setting of SS-RTA, ODS must be suspected when a patient with flaccid quadriparesis does not respond to the correction of potassium or develops additional neurological features along with a rise in sodium. Defective functions of AQPs may be a possible mechanism linking demyelinating CNS lesions, SS, and RTA. Studies evaluating AQP functions and serum antibodies against AQPs in these conditions are warranted.
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Affiliation(s)
- Pulukool Sandhya
- Department of Rheumatology, St Stephen's Hospital, Delhi-110054, India.
| | - Tetsuya Akaishi
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.
| | - Kazuo Fujihara
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.
| | - Masashi Aoki
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.
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6
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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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Aquaporins: Unexpected actors in autoimmune diseases. Clin Exp Rheumatol 2022; 21:103131. [PMID: 35690248 DOI: 10.1016/j.autrev.2022.103131] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/07/2022] [Indexed: 11/21/2022]
Abstract
Aquaporins (AQPs), transmembrane proteins allowing the passage of water and sometimes other small solutes and molecules, are involved in autoimmune diseases including neuromyelitis optica, Sjögren's syndrome and rheumatoid arthritis. Both autoantibodies against AQPs and altered expression and/or trafficking of AQPs in various tissue cell types as well as inflammatory cells are playing key roles in pathogenesis of autoimmune diseases. Detection of autoantibodies against AQP4 in the central nervous system has paved the way for a deeper understanding in disease pathophysiology as well as enabling diagnosis. This review provides a comprehensive summary of the roles of AQPs in autoimmune diseases.
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8
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Lee A, Yoo DK, Lee Y, Jeon S, Jung S, Noh J, Ju S, Hwang S, Kim HH, Kwon S, Chung J, Choi Y. Induction of Anti-Aquaporin 5 Autoantibody Production by Immunization with a Peptide Derived from the Aquaporin of Prevotella melaninogenica Leads to Reduced Salivary Flow in Mice. Immune Netw 2021; 21:e34. [PMID: 34796038 PMCID: PMC8568913 DOI: 10.4110/in.2021.21.e34] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/19/2021] [Accepted: 10/14/2021] [Indexed: 12/12/2022] Open
Abstract
Sjögren's syndrome (SS) is an autoimmune disease characterized by dryness of the mouth and eyes. The glandular dysfunction in SS involves not only T cell-mediated destruction of the glands but also autoantibodies against the type 3 muscarinic acetylcholine receptor or aquaporin 5 (AQP5) that interfere with the secretion process. Studies on the breakage of tolerance and induction of autoantibodies to these autoantigens could benefit SS patients. To break tolerance, we utilized a PmE-L peptide derived from the AQP5-homologous aquaporin of Prevotella melaninogenica (PmAqp) that contained both a B cell "E" epitope and a T cell epitope. Repeated subcutaneous immunization of C57BL/6 mice with the PmE-L peptide efficiently induced the production of Abs against the "E" epitope of mouse/human AQP5 (AQP5E), and we aimed to characterize the antigen specificity, the sequences of AQP5E-specific B cell receptors, and salivary gland phenotypes of these mice. Sera containing anti-AQP5E IgG not only stained mouse Aqp5 expressed in the submandibular glands but also detected PmApq and PmE-L by immunoblotting, suggesting molecular mimicry. Characterization of the AQP5E-specific autoantibodies selected from the screening of phage display Ab libraries and mapping of the B cell receptor repertoires revealed that the AQP5E-specific B cells acquired the ability to bind to the Ag through cumulative somatic hypermutation. Importantly, animals with anti-AQP5E Abs had decreased salivary flow rates without immune cell infiltration into the salivary glands. This model will be useful for investigating the role of anti-AQP5 autoantibodies in glandular dysfunction in SS and testing new therapeutics targeting autoantibody production.
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Affiliation(s)
- Ahreum Lee
- Department of Immunology and Molecular Microbiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea
| | - Duck Kyun Yoo
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Biomedical Science, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Yonghee Lee
- Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Korea
| | - Sumin Jeon
- Department of Immunology and Molecular Microbiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea
| | - Suhan Jung
- Department of Cell and Developmental Biology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 08826, Korea
| | - Jinsung Noh
- Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Korea
| | - Soyeon Ju
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Biomedical Science, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Siwon Hwang
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Biomedical Science, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Hong Hee Kim
- Department of Cell and Developmental Biology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 08826, Korea
| | - Sunghoon Kwon
- Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Korea.,Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Korea.,BK21+ Creative Research Engineer Development for IT, Seoul National University, Seoul 08826, Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Korea.,Institutes of Entrepreneurial BioConvergence, Seoul National University, Seoul 08826, Korea
| | - Junho Chung
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Biomedical Science, Seoul National University College of Medicine, Seoul 03080, Korea.,Cancer Research Institute, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Youngnim Choi
- Department of Immunology and Molecular Microbiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea
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9
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Ala M, Mohammad Jafari R, Hajiabbasi A, Dehpour AR. Aquaporins and diseases pathogenesis: From trivial to undeniable involvements, a disease-based point of view. J Cell Physiol 2021; 236:6115-6135. [PMID: 33559160 DOI: 10.1002/jcp.30318] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 01/01/2023]
Abstract
Aquaporins (AQPs), as transmembrane proteins, were primarily identified as water channels with the ability of regulating the transmission of water, glycerol, urea, and other small-sized molecules. The classic view of AQPs involvement in therapeutic plan restricted them and their regulators into managing only a narrow spectrum of the diseases such as diabetes insipidus and the syndrome of inappropriate ADH secretion. However, further investigations performed, especially in the third millennium, has found that their cooperation in water transmission control can be manipulated to handle other burden-imposing diseases such as cirrhosis, heart failure, Meniere's disease, cancer, bullous pemphigoid, eczema, and Sjögren's syndrome.
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Affiliation(s)
- Moein Ala
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Razieh Mohammad Jafari
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Asghar Hajiabbasi
- Guilan Rheumatology Research Center, Razi Hospital, Guilan University of Medical Sciences, Rasht, Iran
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Brain and Spinal Cord Injury Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
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10
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Cui F, Hu M, Li R, Li B, Huang D, Ma W, Jia X, Lv Z. Insulin on changes in expressions of aquaporin-1, aquaporin-5, and aquaporin-8 in submandibular salivary glands of rats with Streptozotocin-induced diabetes. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2021; 14:221-229. [PMID: 33564354 PMCID: PMC7868788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
OBJECTIVE This study aimed to explore the relationship between diabetic xerostomia and changes in aquaporin-1 (AQP1), aquaporin-5 (AQP5), and aquaporin-8 (AQP8) expression in the submandibular glands (SMGs), to further study the pathogenesis of diabetic xerostomia and to observe the therapeutic effect of insulin (INS). METHODS Thirty SD rats were randomized equally into 3 groups: control group, diabetic model (DM) group and insulin (INS) group (n=10, respectively). The control group received no treatment. DM group and INS group were induced by a high-fat diet and streptozotocin intraperitoneal injection. After establishment of a diabetic rat model, the rats in INS group were treated with insulin. Then all rats were fed continuously with ordinary diet for 2 months. H&E staining was used to describe morphologic changes in the SMGs of rats. Immunohistochemistry was used to analyze the expressions and localization of AQP1, AQP5, and AQP8 in the SMGs. Computer image analysis was used to detect the mean optical density (MOD) values of AQP1, AQP5, and AQP8 expression, and changes in the diameters of acini and ducts. RESULTS The acini were mildly atrophied and the acinar cells were rearranged in an irregular way. The morphology of insulin-administered diabetic SMGs was similar to that of the control group. The acinar average circumference and GCT average diameter in DM group were significantly reduced (P<0.05). The acinar average circumference and GCT average diameter of INS group were significantly increased (P<0.05). The expressions of AQP1, AQP5, and AQP8 were significantly reduced in DM group (P<0.05). The expressions of AQP1, AQP5, and AQP8 in INS group were significantly increased (P<0.05). CONCLUSION The decreased expressions of AQP1, AQP5, and AQP8 led to decreased salivary secretion of SMGs in diabetic rats, which may be involved in the pathogenesis of diabetic xerostomia. Insulin could up-regulate the expressions of AQP1, AQP5 and AQP8, and play a protective role in the secretory function of diabetic SMGs.
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Affiliation(s)
- Fangqin Cui
- Department of Pathophysiology, Bengbu Medical CollegeBengbu 233030, China
| | - Mingji Hu
- Department of Orthopedics, The Second People’s Hospital of BengbuBengbu 233030, China
| | - Ran Li
- Department of Pathology, The First Affiliated Hospital of Bengbu, Medical College, Bengbu Medical CollegeBengbu 233030, China
| | - Bao Li
- Department of Histology and Embryology, Anhui Medical UniversityHefei 230032, China
| | - Dake Huang
- Department of Histology and Embryology, Anhui Medical UniversityHefei 230032, China
| | - Wenhao Ma
- Department of Histology and Embryology, Anhui Medical UniversityHefei 230032, China
| | - Xuemei Jia
- Department of Histology and Embryology, Anhui Medical UniversityHefei 230032, China
| | - Zhengmei Lv
- Department of Histology and Embryology, Anhui Medical UniversityHefei 230032, China
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11
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Dong SH, Kim SS, Kim SH, Yeo SG. Expression of aquaporins in inner ear disease. Laryngoscope 2019; 130:1532-1539. [PMID: 31593306 DOI: 10.1002/lary.28334] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 09/05/2019] [Accepted: 09/10/2019] [Indexed: 12/22/2022]
Abstract
The inner ear is responsible for hearing and balance and consists of a membranous labyrinth within a bony labyrinth. The balance structure is divided into the otolith organ that recognizes linear acceleration and the semicircular canal that is responsible for rotational movement. The cochlea is the hearing organ. The external and middle ear are covered with skin and mucosa, respectively, and the space is filled with air, whereas the inner ear is composed of endolymph and perilymph. The inner ear is a fluid-filled sensory organ composed of hair cells with cilia on the upper part of the cells that convert changes in sound energy and balance into electric energy through the hair cells to transmit signals to the auditory nerve through synapses. Aquaporins (AQPs) are a family of transmembrane proteins present in all species that can be roughly divided into three subfamilies according to structure and function: 1) classical AQP, 2) aquaglyceroporin, and 3) superaquaporin. Currently, the subfamily of mammalian species is known to include 13 AQP members (AQP0-AQP12). AQPs have a variety of functions depending on their structure and are related to inner ear diseases such as Meniere's disease, sensorineural hearing loss, and presbycusis. Additional studies on the relationship between the inner ear and AQPs may be helpful in the diagnosis and treatment of inner ear disease. Laryngoscope, 130:1532-1539, 2020.
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Affiliation(s)
- Sung Hwa Dong
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Sung Su Kim
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Sang Hoon Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Seung Geun Yeo
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School, Kyung Hee University, Seoul, South Korea.,Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate School, Kyung Hee University, Seoul, South Korea
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12
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Alam J, Jeon S, Choi Y. Determination of Anti-aquaporin 5 Autoantibodies by Immunofluorescence Cytochemistry. Methods Mol Biol 2018; 1901:79-87. [PMID: 30539569 DOI: 10.1007/978-1-4939-8949-2_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Cell-based assay by immunofluorescence cytochemistry (CBA-IFC) has been shown to be the most accurate method to detect anti-aquaporin (AQP) 4 autoantibodies. Detection of anti-AQP5 autoantibodies is delicate, which depends on the proper expression of AQP5 on the plasma membrane. Here, we describe methods to determine anti-AQP5 autoantibodies by CBA-IFC. Both anti-AQP5 IgG and IgA can be detected by this method.
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Affiliation(s)
- Jehan Alam
- Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
- Mary and Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, NE, USA
| | - Sumin Jeon
- Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Youngnim Choi
- Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
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Alam J, Koh JH, Kwok SK, Park SH, Park K, Choi Y. Functional Epitopes for Anti-Aquaporin 5 Antibodies in Sjögren Syndrome. J Dent Res 2017; 96:1414-1421. [PMID: 28665757 DOI: 10.1177/0022034517717965] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We recently reported the presence of anti-aquaporin 5 (AQP5) immunoglobulin G (IgG) in patients with primary Sjögren syndrome (SS) with a sensitivity of 0.73 and a specificity of 0.68. The aim of this study was to identify functional epitopes for the anti-AQP5 autoantibodies detected in control subjects and patients with SS. Recognition of epitopes by anti-AQP5 autoantibodies in sera ( n = 13 for control and n = 24 for SS) or purified IgG ( n = 1 for control and n = 3 for SS) was evaluated by indirect immunofluorescence (IIF) assay performed in the presence or absence of peptides corresponding to the second transmembrane helix and extracellular loops A, C, and E of AQP5. Functional epitopes were determined by measuring the effects of purified IgG and neutralizing peptides on transepithelial osmotic permeability (PfT) of MDCK cells expressing AQP5. In the IIF assay, 89% of SS samples were inhibited by at least 1 peptide, while only half of control samples were inhibited by any peptide. Overall, SS samples were inhibited by peptides corresponding to extracellular loops A, C, and E by 40% to 50%, whereas control samples were inhibited only by peptides corresponding to loop E by <20%. A cyclized peptide (E1) mimicking loop E was most frequently recognized and best differentiated between the SS and control samples. Incubation of MDCK-AQP5 cells with SS but not with control IgG, significantly decreased PfT, which was reversed by neutralization of IgG binding to any of the extracellular loops. In conclusion, the anti-AQP5 autoantibodies detected in control and SS groups showed differences in fine specificity to the functional epitopes of AQP5. The prevalent recognition of functional epitopes by anti-AQP5 autoantibodies from SS patients suggests that anti-AQP5 autoantibodies act as mediators of glandular hypofunction and are a potential therapeutic target in SS.
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Affiliation(s)
- J Alam
- 1 School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - J H Koh
- 2 Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea
| | - S-K Kwok
- 2 Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea
| | - S-H Park
- 2 Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea
| | - K Park
- 1 School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Y Choi
- 1 School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
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