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Kobayashi K, Mochizuki J, Yamazaki F, Sashihara T. Yogurt starter strains ameliorate intestinal barrier dysfunction via activating AMPK in Caco-2 cells. Tissue Barriers 2024; 12:2184157. [PMID: 36852963 PMCID: PMC10832913 DOI: 10.1080/21688370.2023.2184157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 02/19/2023] [Indexed: 03/01/2023] Open
Abstract
Lactic acid bacteria (LAB) are commonly used probiotics that improve human health in various aspects. We previously reported that yogurt starter strains, Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131, potentially enhance the intestinal epithelial barrier function by inducing the expression of antimicrobial peptides in the small intestine. However, their effects on physical barrier functions remain unknown. In this study, we found that both strains ameliorated the decreased trans-epithelial resistance and the increased permeability of fluorescein isothiocyanate-dextran induced by tumor necrosis factor (TNF)-α and interferon (IFN)-γ in Caco-2 cells. We also demonstrated that LAB prevented a decrease in the expression and disassembly of tight junctions (TJs) induced by TNF-α and IFN-γ. To assess the repair activity of TJs, a calcium switch assay was performed. Both strains were found to promote the reassembly of TJs, and their activity was canceled by the inhibitor of AMP-activated protein kinase (AMPK). Moreover, these strains showed increased AMPK phosphorylation. These observations suggest that the strains ameliorated physical barrier dysfunction via the activation of AMPK. The activities preventing barrier destruction induced by TNF-α and IFN-γ were strain-dependent. Several strains containing L. bulgaricus 2038 and S. thermophilus 1131 significantly suppressed the barrier impairment, and L. bulgaricus 2038 showed the strongest activity among them. Our findings suggest that the intake of L. bulgaricus 2038 and S. thermophilus 1131 is a potential strategy for the prevention and repair of leaky gut.
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Affiliation(s)
- Kyosuke Kobayashi
- Food Microbiology and Function Research Laboratories, R&D Division, Meiji Co., Ltd, Tokyo, Japan
| | - Junko Mochizuki
- Food Microbiology and Function Research Laboratories, R&D Division, Meiji Co., Ltd, Tokyo, Japan
| | - Fuka Yamazaki
- Food Microbiology and Function Research Laboratories, R&D Division, Meiji Co., Ltd, Tokyo, Japan
| | - Toshihiro Sashihara
- Food Microbiology and Function Research Laboratories, R&D Division, Meiji Co., Ltd, Tokyo, Japan
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2
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Cong X, Mao XD, Wu LL, Yu GY. The role and mechanism of tight junctions in the regulation of salivary gland secretion. Oral Dis 2024; 30:3-22. [PMID: 36825434 DOI: 10.1111/odi.14549] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/27/2023] [Accepted: 02/21/2023] [Indexed: 02/25/2023]
Abstract
Tight junctions (TJs) are cell-cell interactions that localize at the most apical portion of epithelial/endothelial cells. One of the predominant functions of TJs is to regulate material transport through paracellular pathway, which serves as a selective barrier. In recent years, the expression and function of TJs in salivary glands has attracted great interest. The characteristics of multiple salivary gland TJ proteins have been identified. During salivation, the activation of muscarinic acetylcholine receptor and transient receptor potential vanilloid subtype 1, as well as other stimuli, promote the opening of acinar TJs by inducing internalization of TJs, thereby contributing to increased paracellular permeability. Besides, endothelial TJs are also redistributed with leakage of blood vessels in cholinergic-stimulated submandibular glands. Furthermore, under pathological conditions, such as Sjögren's syndrome, diabetes mellitus, immunoglobulin G4-related sialadenitis, and autotransplantation, the integrity and barrier function of TJ complex are impaired and may contribute to hyposalivation. Moreover, in submandibular glands of Sjögren's syndrome mouse model and patients, the endothelial barrier is disrupted and involved in hyposecretion and lymphocytic infiltration. These findings enrich our understanding of the secretory mechanisms that link the importance of epithelial and endothelial TJ functions to salivation under both physiological and pathophysiological conditions.
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Affiliation(s)
- Xin Cong
- Center for Salivary Gland Diseases, Peking University School and Hospital of Stomatology & National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
- Department of Physiology and Pathophysiology, Peking University School of Basic Sciences, Beijing, China
| | - Xiang-Di Mao
- Center for Salivary Gland Diseases, Peking University School and Hospital of Stomatology & National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
- Department of Physiology and Pathophysiology, Peking University School of Basic Sciences, Beijing, China
| | - Li-Ling Wu
- Center for Salivary Gland Diseases, Peking University School and Hospital of Stomatology & National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
- Department of Physiology and Pathophysiology, Peking University School of Basic Sciences, Beijing, China
| | - Guang-Yan Yu
- Center for Salivary Gland Diseases, Peking University School and Hospital of Stomatology & National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
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Moonwiriyakit A, Pathomthongtaweechai N, Steinhagen PR, Chantawichitwong P, Satianrapapong W, Pongkorpsakol P. Tight junctions: from molecules to gastrointestinal diseases. Tissue Barriers 2022; 11:2077620. [PMID: 35621376 PMCID: PMC10161963 DOI: 10.1080/21688370.2022.2077620] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Intestinal epithelium functions as a tissue barrier to prevent interaction between the internal compartment and the external milieu. Intestinal barrier function also determines epithelial polarity for the absorption of nutrients and the secretion of waste products. These vital functions require strong integrity of tight junction proteins. In fact, intestinal tight junctions that seal the paracellular space can restrict mucosal-to-serosal transport of hostile luminal contents. Tight junctions can form both an absolute barrier and a paracellular ion channel. Although defective tight junctions potentially lead to compromised intestinal barrier and the development and progression of gastrointestinal (GI) diseases, no FDA-approved therapies that recover the epithelial tight junction barrier are currently available in clinical practice. Here, we discuss the impacts and regulatory mechanisms of tight junction disruption in the gut and related diseases. We also provide an overview of potential therapeutic targets to restore the epithelial tight junction barrier in the GI tract.
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Affiliation(s)
- Aekkacha Moonwiriyakit
- Chakri Naruebodindra Medical Institute, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Samut Prakan, Thailand
| | - Nutthapoom Pathomthongtaweechai
- Chakri Naruebodindra Medical Institute, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Samut Prakan, Thailand
| | - Peter R Steinhagen
- Department of Hepatology and Gastroenterology, Charité Medical School, Berlin, Germany
| | | | | | - Pawin Pongkorpsakol
- Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
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High Glucose Reduces the Paracellular Permeability of the Submandibular Gland Epithelium via the MiR-22-3p/Sp1/Claudin Pathway. Cells 2021; 10:cells10113230. [PMID: 34831451 PMCID: PMC8617860 DOI: 10.3390/cells10113230] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 11/07/2021] [Accepted: 11/08/2021] [Indexed: 12/17/2022] Open
Abstract
Tight junctions (TJs) play an important role in water, ion, and solute transport through the paracellular pathway of epithelial cells; however, their role in diabetes-induced salivary gland dysfunction remains unknown. Here, we found that the TJ proteins claudin-1 and claudin-3 were significantly increased in the submandibular glands (SMGs) of db/db mice and high glucose (HG)-treated human SMGs. HG decreased paracellular permeability and increased claudin-1 and claudin-3 expression in SMG-C6 cells. Knockdown of claudin-1 or claudin-3 reversed the HG-induced decrease in paracellular permeability. MiR-22-3p was significantly downregulated in diabetic SMGs and HG-treated SMG-C6 cells. A miR-22-3p mimic suppressed claudin-1 and claudin-3 expression and abolished the HG-induced increases in claudin-1 and claudin-3 levels in SMG-C6 cells, whereas a miR-22-3p inhibitor produced the opposite effects. Specificity protein-1 (Sp1) was enhanced in diabetic SMGs and HG-treated SMG-C6 cells, which promoted claudin-1 and claudin-3 transcription through binding to the corresponding promoters. A luciferase reporter assay confirmed that miR-22-3p repressed Sp1 by directly targeting the Sp1 mRNA 3′-untranslated region (3′-UTR). Consistently, the miR-22-3p mimic suppressed, whereas the miR-22-3p inhibitor enhanced, the effects of HG on Sp1 expression. Taken together, our results demonstrate a new regulatory pathway through which HG decreases the paracellular permeability of SMG cells by inhibiting miR-22-3p/Sp1-mediated claudin-1 and claudin-3 expression.
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Krishna S, Raghavan S, DasGupta R, Palakodeti D. tRNA-derived fragments (tRFs): establishing their turf in post-transcriptional gene regulation. Cell Mol Life Sci 2021; 78:2607-2619. [PMID: 33388834 PMCID: PMC11073306 DOI: 10.1007/s00018-020-03720-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/02/2020] [Accepted: 11/24/2020] [Indexed: 02/06/2023]
Abstract
Transfer RNA (tRNA)-derived fragments (tRFs) are an emerging class of conserved small non-coding RNAs that play important roles in post-transcriptional gene regulation. High-throughput sequencing of multiple biological samples have identified heterogeneous species of tRFs with distinct functionalities. These small RNAs have garnered a lot of scientific attention due to their ubiquitous expression and versatility in regulating various biological processes. In this review, we highlight our current understanding of tRF biogenesis and their regulatory functions. We summarize the diverse modes of biogenesis through which tRFs are generated and discuss the mechanism through which different tRF species regulate gene expression and the biological implications. Finally, we conceptualize research areas that require focus to strengthen our understanding of the biogenesis and function of tRFs.
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Affiliation(s)
- Srikar Krishna
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, India
- SASTRA University, Thirumalaisamudram, Thanjavur, India
| | - Srikala Raghavan
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, India.
| | - Ramanuj DasGupta
- Precision Oncology, Genome Institute of Singapore, Singapore City, Singapore.
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Olivier S, Pochard C, Diounou H, Castillo V, Divoux J, Alcantara J, Leclerc J, Guilmeau S, Huet C, Charifi W, Varin TV, Daniel N, Foretz M, Neunlist M, Salomon BL, Ghosh P, Marette A, Rolli-Derkinderen M, Viollet B. Deletion of intestinal epithelial AMP-activated protein kinase alters distal colon permeability but not glucose homeostasis. Mol Metab 2021; 47:101183. [PMID: 33548500 PMCID: PMC7921883 DOI: 10.1016/j.molmet.2021.101183] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/21/2021] [Accepted: 02/01/2021] [Indexed: 12/11/2022] Open
Abstract
Objective The intestinal epithelial barrier (IEB) restricts the passage of microbes and potentially harmful substances from the lumen through the paracellular space, and rupture of its integrity is associated with a variety of gastrointestinal disorders and extra-digestive diseases. Increased IEB permeability has been linked to disruption of metabolic homeostasis leading to obesity and type 2 diabetes. Interestingly, recent studies have uncovered compelling evidence that the AMP-activated protein kinase (AMPK) signaling pathway plays an important role in maintaining epithelial cell barrier function. However, our understanding of the function of intestinal AMPK in regulating IEB and glucose homeostasis remains sparse. Methods We generated mice lacking the two α1 and α2 AMPK catalytic subunits specifically in intestinal epithelial cells (IEC AMPK KO) and determined the physiological consequences of intestinal-specific deletion of AMPK in response to high-fat diet (HFD)-induced obesity. We combined histological, functional, and integrative analyses to ascertain the effects of gut AMPK loss on intestinal permeability in vivo and ex vivo and on the development of obesity and metabolic dysfunction. We also determined the impact of intestinal AMPK deletion in an inducible mouse model (i-IEC AMPK KO) by measuring IEB function, glucose homeostasis, and the composition of gut microbiota via fecal 16S rRNA sequencing. Results While there were no differences in in vivo intestinal permeability in WT and IEC AMPK KO mice, ex vivo transcellular and paracellular permeability measured in Ussing chambers was significantly increased in the distal colon of IEC AMPK KO mice. This was associated with a reduction in pSer425 GIV phosphorylation, a marker of leaky gut barrier. However, the expression of tight junction proteins in intestinal epithelial cells and pro-inflammatory cytokines in the lamina propria were not different between genotypes. Although the HFD-fed AMPK KO mice displayed suppression of the stress polarity signaling pathway and a concomitant increase in colon permeability, loss of intestinal AMPK did not exacerbate body weight gain or adiposity. Deletion of AMPK was also not sufficient to alter glucose homeostasis or the acute glucose-lowering action of metformin in control diet (CD)- or HFD-fed mice. CD-fed i-IEC AMPK KO mice also presented higher permeability in the distal colon under homeostatic conditions but, surprisingly, this was not detected upon HFD feeding. Alteration in epithelial barrier function in the i-IEC AMPK KO mice was associated with a shift in the gut microbiota composition with higher levels of Clostridiales and Desulfovibrionales. Conclusions Altogether, our results revealed a significant role of intestinal AMPK in maintaining IEB integrity in the distal colon but not in regulating glucose homeostasis. Our data also highlight the complex interaction between gut microbiota and host AMPK. Deletion of intestinal AMPKα1 and α2 suppresses the stress-polarity signaling (SPS) pathway. Loss of the SPS pathway is associated with increased paracellular permeability in the distal colon. Intestinal AMPK is dispensable for the acute glucose-lowering action of metformin. Loss of intestinal AMPK alters the gut microbiota composition.
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Affiliation(s)
- Séverine Olivier
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France
| | - Camille Pochard
- University of Nantes, INSERM, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Hanna Diounou
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France
| | - Vanessa Castillo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Jordane Divoux
- Sorbonne Université, INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses (CIMI), Paris, France
| | - Joshua Alcantara
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Jocelyne Leclerc
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France
| | - Sandra Guilmeau
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France
| | - Camille Huet
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France
| | - Wafa Charifi
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France
| | - Thibault V Varin
- Québec Heart and Lung Research Institute (IUCPQ) & Institute for Nutrition and Functional Foods (INAF), Laval University Québec, Québec, Canada
| | - Noëmie Daniel
- Québec Heart and Lung Research Institute (IUCPQ) & Institute for Nutrition and Functional Foods (INAF), Laval University Québec, Québec, Canada
| | - Marc Foretz
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France
| | - Michel Neunlist
- University of Nantes, INSERM, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Benoit L Salomon
- Sorbonne Université, INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses (CIMI), Paris, France
| | - Pradipta Ghosh
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA; Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - André Marette
- Québec Heart and Lung Research Institute (IUCPQ) & Institute for Nutrition and Functional Foods (INAF), Laval University Québec, Québec, Canada
| | - Malvyne Rolli-Derkinderen
- University of Nantes, INSERM, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France.
| | - Benoit Viollet
- Université de Paris, Institut Cochin, INSERM, CNRS, F-75014 Paris, France.
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Wei P, Xing Y, Li B, Chen F, Hua H. Proteomics-based analysis indicating α-enolase as a potential biomarker in primary Sjögren's syndrome. Gland Surg 2021; 9:2054-2063. [PMID: 33447556 DOI: 10.21037/gs-20-814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease. Its etiology is not well understood. Salivary glands are the main target organ in pSS, investigating the changes of salivary protein in pSS patients may not only be a valuable way of identifying new biomarkers/antigens for pSS, but also of revealing the pathogenesis underlying this autoimmune disease. In the present study, we aimed to investigate new biomarkers and explore their potential role in pSS. Methods In this study, α-enolase (ENO1) was found to be overexpressed in pSS by 1D gel electrophoresis/mass spectrometry. The finding was verified by Western blots, immunohistochemistry (IHC), and polymerase chain reaction (PCR) results in both saliva and labial salivary glands. The expression level of immunoglobulin G (IgG) antibody to ENO1 was then tested by enzyme-linked immunosorbent assay (ELISA). Results ENO1 autoantibody was found to be overexpressed in pSS compared with healthy controls. The effects of ENO1 overexpression on rat submandibular gland cell line SMG-C6 was investigated in vitro. The expressions of proteins related to saliva secretion and immunomodulatory were upregulated in ENO1 overexpressed SMG-C6 cells. Conclusions Both ENO1 and anti-ENO1 autoantibody are overexpressed in pSS patients. Nevertheless, their potential role in the pathogenesis of pSS warrants further study.
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Affiliation(s)
- Pan Wei
- Department of Oral Medicine, Peking University School and Hospital of Stomatology, Beijing, China
| | - Yixiao Xing
- Department of Oral Medicine, Peking University School and Hospital of Stomatology, Beijing, China
| | - Boya Li
- Department of Oral Medicine, Peking University School and Hospital of Stomatology, Beijing, China
| | - Feng Chen
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, China
| | - Hong Hua
- Department of Oral Medicine, Peking University School and Hospital of Stomatology, Beijing, China
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Shen ZJ, Han YC, Nie MW, Xiang RL, Xie HZ. Analyses of circRNA and mRNA profiles in the submandibular gland in hypertension. Genomics 2020; 113:57-65. [PMID: 33227410 DOI: 10.1016/j.ygeno.2020.11.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 10/06/2020] [Accepted: 11/18/2020] [Indexed: 10/23/2022]
Abstract
The aim of this study was to elucidate the roles played by circular RNAs (circRNAs) in the mechanism underlying submandibular gland (SMG) dysfunction in hypertension. We employed RNA-seq to analyze the circRNA and mRNA expression profiles of SMGs. Seventy-five differentially expressed (DE) circRNAs and 691 DE mRNAs were determined to be significantly altered in spontaneously hypertensive rats. Altered mRNAs were primarily related to the immune system and immune response. Eight circRNAs were selected for further analysis. Cell adhesion molecules were determined to be the most strongly enriched pathway through analysis of DE mRNAs, the coding noncoding gene co-expression (CNC) network and the competitive endogenous RNA (ceRNA) network. The salivary secretion pathway was observed to be notably enriched through analysis of the ceRNA network. These results suggest that the crosstalk among circRNAs may play a crucial role in the development of SMG dysfunction in hypertension.
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Affiliation(s)
- Zhu-Jun Shen
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 1000730, China
| | - Ye-Chen Han
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 1000730, China
| | - Mu-Wen Nie
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 1000730, China
| | - Ruo-Lan Xiang
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, 100191, China
| | - Hong-Zhi Xie
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 1000730, China.
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Liu HM, Huang Y, Li L, Zhang Y, Cong X, Wu LL, Xiang RL. MicroRNA-mRNA expression profiles and functional network of submandibular gland in type 2 diabetic db/db mice. Arch Oral Biol 2020; 120:104947. [PMID: 33113460 DOI: 10.1016/j.archoralbio.2020.104947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/23/2020] [Accepted: 10/04/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Hyposalivation is a common symptom of diabetes. Although microRNAs (miRNAs) play a role in the pathogenesis of diabetes, the specific effects of miRNAs on diabetic salivary glands are not clear. DESIGN We used high-throughput technologies to screen differentially expressed (DE) miRNAs and mRNAs in submandibular gland (SMG) tissues from db/db mice and db/m mice. DE miRNAs and mRNAs were confirmed using quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS Twenty-eight DE miRNAs and 1146 DE mRNAs were identified between the SMG tissues of db/db mice and db/m mice. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated that the DE miRNAs were highly associated with terms related to diverse biological processes and signalling pathways. Of the related pathways, the tight junction pathway, autophagy pathway and transforming growth factor-β (TGF-β) signalling pathway were notable. AKT serine/threonine kinase 3 (AKT3) and phosphoinositide-3 kinase catalytic subunit delta (PIK3CD) may also play important roles in the development of diabetes-mediated hyposalivation. CONCLUSIONS Our research described the miRNA-mRNA expression profiles and miRNA-mRNA network in the SMG tissues of db/db mice. These results provide possible molecular mechanisms of diabetes-induced hyposalivation and information for further studies.
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Affiliation(s)
- Hui-Min Liu
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, 100191, China
| | - Yan Huang
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, 100081, China
| | - Li Li
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, 100191, China
| | - Yan Zhang
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, 100191, China
| | - Xin Cong
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, 100191, China
| | - Li-Ling Wu
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, 100191, China
| | - Ruo-Lan Xiang
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, 100191, China.
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Angé M, Castanares-Zapatero D, De Poortere J, Dufeys C, Courtoy GE, Bouzin C, Quarck R, Bertrand L, Beauloye C, Horman S. α1AMP-Activated Protein Kinase Protects against Lipopolysaccharide-Induced Endothelial Barrier Disruption via Junctional Reinforcement and Activation of the p38 MAPK/HSP27 Pathway. Int J Mol Sci 2020; 21:ijms21155581. [PMID: 32759774 PMCID: PMC7432762 DOI: 10.3390/ijms21155581] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/28/2020] [Accepted: 07/30/2020] [Indexed: 12/11/2022] Open
Abstract
Vascular hyperpermeability is a determinant factor in the pathophysiology of sepsis. While, AMP-activated protein kinase (AMPK) is known to play a role in maintaining endothelial barrier function in this condition. Therefore, we investigated the underlying molecular mechanisms of this protective effect. α1AMPK expression and/or activity was modulated in human dermal microvascular endothelial cells using either α1AMPK-targeting small interfering RNA or the direct pharmacological AMPK activator 991, prior to lipopolysaccharide (LPS) treatment. Western blotting was used to analyze the expression and/or phosphorylation of proteins that compose cellular junctions (zonula occludens-1 (ZO-1), vascular endothelial cadherin (VE-Cad), connexin 43 (Cx43)) or that regulate actin cytoskeleton (p38 MAPK; heat shock protein 27 (HSP27)). Functional endothelial permeability was assessed by in vitro Transwell assays, and quantification of cellular junctions in the plasma membrane was assessed by immunofluorescence. Actin cytoskeleton remodeling was evaluated through actin fluorescent staining. We consequently demonstrate that α1AMPK deficiency is associated with reduced expression of CX43, ZO-1, and VE-Cad, and that the drastic loss of CX43 is likely responsible for the subsequent decreased expression and localization of ZO-1 and VE-Cad in the plasma membrane. Moreover, α1AMPK activation by 991 protects against LPS-induced endothelial barrier disruption by reinforcing cortical actin cytoskeleton. This is due to a mechanism that involves the phosphorylation of p38 MAPK and HSP27, which is nonetheless independent of the small GTPase Rac1. This results in a drastic decrease of LPS-induced hyperpermeability. We conclude that α1AMPK activators that are suitable for clinical use may provide a specific therapeutic intervention that limits sepsis-induced vascular leakage.
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Affiliation(s)
- Marine Angé
- Pôle de Recherche Cardiovasculaire (CARD), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (M.A.); (D.C.-Z.); (J.D.P.); (C.D.); (L.B.); (C.B.)
| | - Diego Castanares-Zapatero
- Pôle de Recherche Cardiovasculaire (CARD), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (M.A.); (D.C.-Z.); (J.D.P.); (C.D.); (L.B.); (C.B.)
- Division of Intensive Care, Cliniques Universitaires Saint Luc, 1200 Brussels, Belgium
| | - Julien De Poortere
- Pôle de Recherche Cardiovasculaire (CARD), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (M.A.); (D.C.-Z.); (J.D.P.); (C.D.); (L.B.); (C.B.)
| | - Cécile Dufeys
- Pôle de Recherche Cardiovasculaire (CARD), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (M.A.); (D.C.-Z.); (J.D.P.); (C.D.); (L.B.); (C.B.)
| | - Guillaume E. Courtoy
- IREC Imaging Platform, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (G.E.C.); (C.B.)
| | - Caroline Bouzin
- IREC Imaging Platform, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (G.E.C.); (C.B.)
| | - Rozenn Quarck
- Department of Chronic Diseases & Metabolism (CHROMETA), Laboratory of Respiratory Diseases & Thoracic Surgery (BREATHE), KU Leuven, 3000 Leuven, Belgium;
| | - Luc Bertrand
- Pôle de Recherche Cardiovasculaire (CARD), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (M.A.); (D.C.-Z.); (J.D.P.); (C.D.); (L.B.); (C.B.)
| | - Christophe Beauloye
- Pôle de Recherche Cardiovasculaire (CARD), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (M.A.); (D.C.-Z.); (J.D.P.); (C.D.); (L.B.); (C.B.)
- Division of Cardiology, Cliniques Universitaires Saint-Luc, 1200 Brussels, Belgium
| | - Sandrine Horman
- Pôle de Recherche Cardiovasculaire (CARD), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (M.A.); (D.C.-Z.); (J.D.P.); (C.D.); (L.B.); (C.B.)
- Correspondence: ; Tel.: +32-2-764-55-66
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11
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Meoli L, Günzel D. Channel functions of claudins in the organization of biological systems. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183344. [PMID: 32442419 DOI: 10.1016/j.bbamem.2020.183344] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 04/27/2020] [Accepted: 05/05/2020] [Indexed: 02/07/2023]
Abstract
Claudins are tight junction proteins mostly appreciated in their function of paracellular barrier-formation. Compared to a virtual absence of any tight junctions, their paracellular sealing role certainly stands out. Yet, it was recognized immediately after the discovery of the first claudins, that some members of the claudin protein family were able to convey size and charge selectivity to the paracellular pathway. Thus, paracellular permeability can be fine-tuned according to the physiological needs of a tissue by inserting these channel-forming claudins into tight junction strands. Precise permeability adjustment is further suggested by the presence of numerous isoforms of channel-forming claudins (claudin-10b-, -15-, -16-like isoforms) in various vertebrate taxa. Moreover, their expression and localization are controlled by multiple transcriptional and posttranslational mechanisms. Consequently, mutation or dysregulation of channel-forming claudins can cause severe diseases. The present review therefore aims at providing an up-to-date report of the current research on these aspects of channel-forming claudins and their possible implications on future developments.
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Affiliation(s)
- Luca Meoli
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany
| | - Dorothee Günzel
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany.
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12
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Huang Y, Mao QY, Shi XJ, Cong X, Zhang Y, Wu LL, Yu GY, Xiang RL. Disruption of tight junctions contributes to hyposalivation of salivary glands in a mouse model of type 2 diabetes. J Anat 2020; 237:556-567. [PMID: 32374057 DOI: 10.1111/joa.13203] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 03/23/2020] [Accepted: 03/24/2020] [Indexed: 12/13/2022] Open
Abstract
Tight junction (TJ) plays an important role in regulating paracellular fluid transport in salivary glands; however, little is known about the involvement of TJs in diabetes salivary glands. This study aimed to investigate the alterations of TJs and their possible contribution in diabetes-induced hyposalivation. Here, we observed that the morphologies of submandibular glands (SMGs) were impaired, characterized by enlarged acini accumulation with giant secretory granules, which were significantly reduced in atrophic ducts in SMGs of db/db mice, a spontaneous model of type-2 diabetes. However, the secretory granules were increased and scattered in the acini of diabetes parotid glands (PGs). Other ultrastructural damages including swollen mitochondria, expansive endoplasmic reticulum, and autophagosomes were observed in the diabetes group. The levels of TJ proteins including claudin-1 (Cldn1) and claudin-3 (Cldn3) were increased, whereas those of claudin-4 (Cldn4), occludin (Ocln), and zonula occludens-1 (ZO-1) were decreased in SMGs of db/db mice. Higher Cldn1 and Cldn3 and lower claudin-10 (Cldn10) and Ocln levels were observed in PGs of diabetes mice. Taken together, the structures of SMGs and PGs were impaired in diabetes mice, and the disruption of TJ integrity in both SMGs and PGs may contribute to diabetes-induced hyposalivation.
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Affiliation(s)
- Yan Huang
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China
| | - Qian-Ying Mao
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China
| | - Xi-Jin Shi
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Xin Cong
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Yan Zhang
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Li-Ling Wu
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Guang-Yan Yu
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China
| | - Ruo-Lan Xiang
- Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
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13
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Reciprocal Association between the Apical Junctional Complex and AMPK: A Promising Therapeutic Target for Epithelial/Endothelial Barrier Function? Int J Mol Sci 2019; 20:ijms20236012. [PMID: 31795328 PMCID: PMC6928779 DOI: 10.3390/ijms20236012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 11/26/2019] [Accepted: 11/26/2019] [Indexed: 12/17/2022] Open
Abstract
Epithelial/endothelial cells adhere to each other via cell–cell junctions including tight junctions (TJs) and adherens junctions (AJs). TJs and AJs are spatiotemporally and functionally integrated, and are thus often collectively defined as apical junctional complexes (AJCs), regulating a number of spatiotemporal events including paracellular barrier, selective permeability, apicobasal cell polarity, mechano-sensing, intracellular signaling cascades, and epithelial morphogenesis. Over the past 15 years, it has been acknowledged that adenosine monophosphate (AMP)-activated protein kinase (AMPK), a well-known central regulator of energy metabolism, has a reciprocal association with AJCs. Here, we review the current knowledge of this association and show the following evidences: (1) as an upstream regulator, AJs activate the liver kinase B1 (LKB1)–AMPK axis particularly in response to applied junctional tension, and (2) TJ function and apicobasal cell polarization are downstream targets of AMPK and are promoted by AMPK activation. Although molecular mechanisms underlying these phenomena have not yet been completely elucidated, identifications of novel AMPK effectors in AJCs and AMPK-driven epithelial transcription factors have enhanced our knowledge. More intensive studies along this line would eventually lead to the development of AMPK-based therapies, enabling us to manipulate epithelial/endothelial barrier function.
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14
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Wu J, Gao F, Xu T, Li J, Hu Z, Wang C, Long Y, He X, Deng X, Ren D, Zhou B, Dai T. CLDN1 induces autophagy to promote proliferation and metastasis of esophageal squamous carcinoma through AMPK/STAT1/ULK1 signaling. J Cell Physiol 2019; 235:2245-2259. [PMID: 31498437 DOI: 10.1002/jcp.29133] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 08/23/2019] [Indexed: 12/12/2022]
Abstract
Tight junction is a structural constitution in cell-cell adhesion and play an important role in the maintenance of permeability and integrity of normal epithelial cell barrier. The protein encoded by Claudin 1 (CLDN1), a member of the claudin family, is an integral membrane protein and a component of tight junction strands. CLDN1 has been proved to regulate the proliferation and metastasis of multiple tumors, but little is known about its role in esophageal squamous cell carcinoma (ESCC). Here, we found that CLDN1 was aberrantly increased in ESCC tissues and cell lines, and mainly distributed in the nucleus of tumor cells. Furthermore, we confirmed that CLDN1 promoted the proliferation and metastasis of ESCC by triggering autophagy both in vitro and in vivo. Mechanically, we validated that CLDN1-induced autophagy via increasing Unc-51 like autophagy activating kinase 1 (ULK1) expression through AMP-activated protein kinase (AMPK)/signal transducer and activator of transcription 1 (STAT1) signaling pathway in ESCC cells. Taken together, our findings demonstrated that aberrant expression and distribution of CLDN1 promoted the proliferation and metastasis of esophageal squamous carcinoma by triggering autophagy through AMPK/STAT1/ULK1 signaling pathway.
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Affiliation(s)
- Jian Wu
- Department of Cardio-Thoracic Surgery, The Affiliated Hospital of South West Medical University, Luzhou, Sichuan, China
| | - FengXia Gao
- Department of Immunology, Basic Medicine College, South West Medical University, Luzhou, Sichuan, China
| | - Tao Xu
- Department of Cardio-Thoracic Surgery, The Affiliated Hospital of South West Medical University, Luzhou, Sichuan, China
| | - Jun Li
- Department of Cardio-Thoracic Surgery, The Affiliated Hospital of South West Medical University, Luzhou, Sichuan, China
| | - Zhi Hu
- Department of Cardio-Thoracic Surgery, The Affiliated Hospital of South West Medical University, Luzhou, Sichuan, China
| | - Chao Wang
- Department of Cardio-Thoracic Surgery, The Affiliated Hospital of South West Medical University, Luzhou, Sichuan, China.,Department of Immunology, Basic Medicine College, South West Medical University, Luzhou, Sichuan, China.,Experiment Medicine Center, The Affiliated Hospital of South West Medical University, Luzhou, Sichuan, China.,Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Yang Long
- Experiment Medicine Center, The Affiliated Hospital of South West Medical University, Luzhou, Sichuan, China
| | - XueMei He
- Experiment Medicine Center, The Affiliated Hospital of South West Medical University, Luzhou, Sichuan, China
| | - Xin Deng
- Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China.,Laboratory for Cardiovascular Pharmacology of Department of Pharmacology, The School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - DeLian Ren
- Department of Immunology, Basic Medicine College, South West Medical University, Luzhou, Sichuan, China
| | - Biao Zhou
- Department of Cardio-Thoracic Surgery, The Affiliated Hospital of South West Medical University, Luzhou, Sichuan, China
| | - TianYang Dai
- Department of Cardio-Thoracic Surgery, The Affiliated Hospital of South West Medical University, Luzhou, Sichuan, China
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15
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Zhu L, Han J, Li L, Wang Y, Li Y, Zhang S. Claudin Family Participates in the Pathogenesis of Inflammatory Bowel Diseases and Colitis-Associated Colorectal Cancer. Front Immunol 2019; 10:1441. [PMID: 31316506 PMCID: PMC6610251 DOI: 10.3389/fimmu.2019.01441] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 06/07/2019] [Indexed: 12/17/2022] Open
Abstract
Claudins are a multigene transmembrane protein family comprising at least 27 members. In gastrointestinal tract, claudins are mainly located in the intestinal epithelia; many types of claudins form a network of strands in tight junction plaques within the intercellular space of neighboring epithelial cells and build paracellular selective channels, while others act as signaling proteins and mediates cell behaviors. Claudin dysfunction may contribute to epithelial permeation disorder and multiple intestinal diseases. Over recent years, the importance of claudins in the pathogenesis of inflammatory bowel diseases (IBD) has gained focus and is being investigated. This review analyzes the expression pattern and regulatory mechanism of claudins based on existing evidence and elucidates the fact that claudin dysregulation correlates with increased intestinal permeability, sustained activation of inflammation, epithelial-to-mesenchymal transition (EMT), and tumor progression in IBD as well as consequent colitis-associated colorectal cancer (CAC), possibly shedding new light on further etiologic research and clinical treatments.
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Affiliation(s)
| | | | | | | | | | - Shenghong Zhang
- Division of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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16
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Xiang RL, Huang Y, Zhang Y, Cong X, Zhang ZJ, Wu LL, Yu GY. Type 2 diabetes-induced hyposalivation of the submandibular gland through PINK1/Parkin-mediated mitophagy. J Cell Physiol 2019; 235:232-244. [PMID: 31190343 PMCID: PMC6851669 DOI: 10.1002/jcp.28962] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 05/20/2019] [Accepted: 05/22/2019] [Indexed: 12/11/2022]
Abstract
Diabetes is often accompanied by dysfunction of salivary glands. However, the molecular mechanism remains unclear. The mechanisms that underlie diabetic hyposalivation were studied by db/db mice and SMG‐C6 cells. We found morphological changes and decreased stimulated salivary flow rates of the submandibular gland (SMG) in diabetic mice. We observed structural changes and dysfunction of mitochondria. More mitophagosomes and higher expression of autophagy‐related proteins were detected. Increased levels of proteins PINK1 and Parkin indicate that PINK1/Parkin‐mediated mitophagy was activated in diabetic SMG. Consistently, high glucose (HG) induced mitochondrial dysfunction and PINK1/Parkin‐mediated mitophagy in cultivated SMG‐C6 cells. HG also increased reactive oxygen species (ROS) and lessened activation of antioxidants in SMG‐C6 cells. In addition, HG lowered ERK1/2 phosphorylation and HG‐induced mitophagy was decreased after ERK1/2 was activated by LM22B‐10. Altogether, these data suggest that ROS played a crucial role in diabetes‐induced mitochondrial dysfunction and PINK1/Parkin‐mediated mitophagy and ERK1/2 was required in HG‐induced mitophagy in SMG.
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Affiliation(s)
- Ruo-Lan Xiang
- Center for Salivary Gland Diseases of Peking University School and Hospital of Stomatology, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, China
| | - Yan Huang
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China
| | - Yan Zhang
- Center for Salivary Gland Diseases of Peking University School and Hospital of Stomatology, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, China
| | - Xin Cong
- Center for Salivary Gland Diseases of Peking University School and Hospital of Stomatology, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, China
| | - Zhe-Jing Zhang
- Center for Salivary Gland Diseases of Peking University School and Hospital of Stomatology, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, China
| | - Li-Ling Wu
- Center for Salivary Gland Diseases of Peking University School and Hospital of Stomatology, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, and Beijing Key Laboratory of Cardiovascular Receptors Research, Department of Physiology and Pathophysiology, Peking University School of Basic Medical Sciences, Beijing, China
| | - Guang-Yan Yu
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China
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17
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Zhang L, Su JZ, Cai ZG, Lv L, Zou LH, Liu XJ, Wu J, Zhu ZH, Mao C, Wang Y, Peng X, Song B, Li XX, Yu GY. Factors influencing the long-term results of autologous microvascular submandibular gland transplantation for severe dry eye disease. Int J Oral Maxillofac Surg 2019; 48:40-47. [PMID: 30057239 DOI: 10.1016/j.ijom.2018.07.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 05/04/2018] [Accepted: 07/11/2018] [Indexed: 12/13/2022]
Affiliation(s)
- L Zhang
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - J-Z Su
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Z-G Cai
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - L Lv
- Department of Ophthalmology, Affiliated Beijing Tong Ren Hospital, Capital University of Medical Science, Beijing, 100730, China
| | - L-H Zou
- Department of Ophthalmology, Affiliated Beijing Tong Ren Hospital, Capital University of Medical Science, Beijing, 100730, China
| | - X-J Liu
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - J Wu
- Department of Ophthalmology, Affiliated Beijing Tong Ren Hospital, Capital University of Medical Science, Beijing, 100730, China; Department of Ophthalmology, Affiliated Beijing Bo Ai Hospital, Capital University of Medical Science, Beijing, 100068, China
| | - Z-H Zhu
- Department of Stomatology, Affiliated Beijing Tong Ren Hospital, Capital University of Medical Science, Beijing, 100730, China
| | - C Mao
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Y Wang
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - X Peng
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - B Song
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - X-X Li
- Clinical Laboratory, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - G-Y Yu
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, 100081, China.
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18
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Bierbaumer L, Schwarze UY, Gruber R, Neuhaus W. Cell culture models of oral mucosal barriers: A review with a focus on applications, culture conditions and barrier properties. Tissue Barriers 2018; 6:1479568. [PMID: 30252599 PMCID: PMC6389128 DOI: 10.1080/21688370.2018.1479568] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Understanding the function of oral mucosal epithelial barriers is essential for a plethora of research fields such as tumor biology, inflammation and infection diseases, microbiomics, pharmacology, drug delivery, dental and biomarker research. The barrier properties are comprised by a physical, a transport and a metabolic barrier, and all these barrier components play pivotal roles in the communication between saliva and blood. The sum of all epithelia of the oral cavity and salivary glands is defined as the blood-saliva barrier. The functionality of the barrier is regulated by its microenvironment and often altered during diseases. A huge array of cell culture models have been developed to mimic specific parts of the blood-saliva barrier, but no ultimate standard in vitro models have been established. This review provides a comprehensive overview about developed in vitro models of oral mucosal barriers, their applications, various cultivation protocols and corresponding barrier properties.
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Affiliation(s)
- Lisa Bierbaumer
- a Competence Unit Molecular Diagnostics, Center Health and Bioresources, Austrian Institute of Technology (AIT) GmbH , Vienna , Austria
| | - Uwe Yacine Schwarze
- b Department of Oral Biology , School of Dentistry, Medical University of Vienna , Vienna , Austria.,c Austrian Cluster for Tissue Regeneration , Vienna , Austria
| | - Reinhard Gruber
- b Department of Oral Biology , School of Dentistry, Medical University of Vienna , Vienna , Austria.,c Austrian Cluster for Tissue Regeneration , Vienna , Austria.,d Department of Periodontology , School of Dental Medicine, University of Bern , Bern , Switzerland
| | - Winfried Neuhaus
- a Competence Unit Molecular Diagnostics, Center Health and Bioresources, Austrian Institute of Technology (AIT) GmbH , Vienna , Austria
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19
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Zhu MJ, Sun X, Du M. AMPK in regulation of apical junctions and barrier function of intestinal epithelium. Tissue Barriers 2018; 6:1-13. [PMID: 30130441 DOI: 10.1080/21688370.2018.1487249] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Gut epithelium covers the inner layer of the gastrointestinal tract and provides a physical barrier to separate the host from its external environment, and its barrier function is critical for maintaining host health. AMP-activated protein kinase (AMPK) as a master regulator of energy metabolism plays a critical role in epithelial barrier function. AMPK activation promotes epithelial differentiation and facilitates cell polarity establishment, both of which strengthen epithelial barrier. In addition, AMPK promotes the assembly of tight junctions and adherens junctions by direct phosphorylation of proteins composing apical junctions, junctional anchors, and cytoskeletons. Pharmacological and nutraceutical compounds, as well as physiological states triggering AMPK activation strengthen epithelial barrier function. This review summarized recent progress in delineating the regulatory roles of AMPK in apical junction formation and barrier function of intestinal epithelium.
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Affiliation(s)
- Mei-Jun Zhu
- a School of Food Science , Washington State University , Pullman , WA, USA
| | - Xiaofei Sun
- a School of Food Science , Washington State University , Pullman , WA, USA
| | - Min Du
- b Department of Animal Sciences , Washington State University , Pullman , WA, USA
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20
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Ca 2+-CaMKKβ pathway is required for adiponectin-induced secretion in rat submandibular gland. J Mol Histol 2017; 49:99-110. [PMID: 29243095 DOI: 10.1007/s10735-017-9750-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 12/05/2017] [Indexed: 10/18/2022]
Abstract
Adiponectin functions as a promoter of saliva secretion in rat submandibular gland via activation of adenosine monophosphate-activated protein kinase (AMPK) and increased paracellular permeability. Ca2+ mobilization is the primary signal for fluid secretion in salivary acinar cells. However, whether intracellular Ca2+ mobilization is involved in adiponectin-induced salivary secretion is unknown. Here, we found that full-length adiponectin (fAd) increased intracellular Ca2+ and saliva secretion in submandibular glands. Pre-perfusion with ethylene glycol-bis (2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) combined with thapsigargin (TG), an endoplasmic reticulum Ca2+-ATPase inhibitor, abolished fAd-induced salivary secretion, AMPK phosphorylation, and enlarged tight junction (TJ) width. Furthermore, in cultured SMG-C6 cells, co-pretreatment with EGTA and TG suppressed fAd-decreased transepithelial electrical resistance and increased 4-kDa FITC-dextran flux responses. Moreover, fAd increased phosphorylation of calcium/calmodulin-dependent protein kinase (CaMKKβ), a major kinase that is activated by elevated levels of intracellular Ca2+, but not liver kinase B1 phosphorylation. Pre-perfusion of the isolated gland with STO-609, an inhibitor of CaMKKβ, abolished fAd-induced salivary secretion, AMPK activation, and enlarged TJ width. CaMKKβ shRNA suppressed, whereas CaMKKβ re-expression rescued fAd-increased paracellular permeability. Taken together, these results indicate that adiponectin induced Ca2+ modulation in rat submandibular gland acinar cells. Ca2+-CaMKKβ pathway is required for adiponectin-induced secretion through mediating AMPK activation and increase in paracellular permeability in rat submandibular glands.
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21
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Zhang D, Tang Q, Zheng G, Wang C, Zhou Y, Wu Y, Xuan J, Tian N, Wang X, Wu Y, Xu H, Zhang X. Metformin ameliorates BSCB disruption by inhibiting neutrophil infiltration and MMP-9 expression but not direct TJ proteins expression regulation. J Cell Mol Med 2017; 21:3322-3336. [PMID: 28699677 PMCID: PMC5706495 DOI: 10.1111/jcmm.13235] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 04/14/2017] [Indexed: 12/12/2022] Open
Abstract
Blood-spinal cord barrier (BSCB) disruption is a major process for the secondary injury of spinal cord injury (SCI) and is considered to be a therapeutic target for SCI. Previously, we demonstrated that metformin could improve functional recovery after SCI; however, the effect of metformin on BSCB is still unknown. In this study, we found that metformin could prevent the loss of tight junction (TJ) proteins at day 3 after SCI in vivo, but in vitro there was no significant difference of these proteins between control and metformin treatment in endothelial cells. This indicated that metformin-induced BSCB protection might not be mediated by up-regulating TJ proteins directly, but by inhibiting TJ proteins degradation. Thus, we investigated the role of metformin on MMP-9 and neutrophils infiltration. Neutrophils infiltration is the major source of the enhanced MMP-9 in SCI. Our results showed that metformin decreased MMP-9 production and blocked neutrophils infiltration at day 1 after injury, which might be related to ICAM-1 down-regulation. Also, our in vitro study showed that metformin inhibited TNF-α-induced MMP-9 up-regulation in neutrophils, which might be mediated via an AMPK-dependent pathway. Together, it illustrated that metformin prevented the breakdown of BSCB by inhibiting neutrophils infiltration and MMP-9 production, but not by up-regulating TJ proteins expression. Our study may help to better understand the working mechanism of metformin on SCI.
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Affiliation(s)
- Di Zhang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Qian Tang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Gang Zheng
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Chenggui Wang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Yifei Zhou
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Yaosen Wu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Jun Xuan
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Naifeng Tian
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Xiangyang Wang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Yan Wu
- Department of Orthopaedics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Huazi Xu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Xiaolei Zhang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China.,Chinese Orthopaedic Regenerative Medicine Society, Wenzhou, Zhejiang Province, China
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22
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Runggaldier D, Pradas LG, Neckel PH, Mack AF, Hirt B, Gleiser C. Claudin expression in the rat endolymphatic duct and sac - first insights into regulation of the paracellular barrier by vasopressin. Sci Rep 2017; 7:45482. [PMID: 28374851 PMCID: PMC5379655 DOI: 10.1038/srep45482] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 02/28/2017] [Indexed: 12/13/2022] Open
Abstract
Hearing and balance functions of the inner ear rely on the homeostasis of the endolymphatic fluid. When disturbed, pathologic endolymphatic hydrops evolves as observed in Menière’s disease. The molecular basis of inner ear fluid regulation across the endolymphatic epithelium is largely unknown. In this study we identified the specific expression of the tight junction (TJ) molecules Claudin 3, 4, 6, 7, 8, 10, and 16 in epithelial preparations of the rat inner ear endolymphatic duct (ED) and endolymphatic sac (ES) by high-throughput qPCR and immunofluorescence confocal microscopy. Further we showed that Claudin 4 in the ES is a target of arginine-vasopressin (AVP), a hormone elevated in Menière’s disease. Moreover, our transmission-electron microscopy (TEM) analysis revealed that the TJs of the ED were shallow and shorter compared to the TJ of the ES indicating facilitation of a paracellular fluid transport across the ED epithelium. The significant differences in the subcellular localization of the barrier-forming protein Claudin 3 between the ED and ES epithelium further support the TEM observations. Our results indicate a high relevance of Claudin 3 and Claudin 4 as important paracellular barrier molecules in the ED and ES epithelium with potential involvement in the pathophysiology of Menière’s disease.
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Affiliation(s)
- Daniel Runggaldier
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Tübingen, Germany
| | - Lidia Garcia Pradas
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Tübingen, Germany
| | - Peter H Neckel
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Tübingen, Germany
| | - Andreas F Mack
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Tübingen, Germany
| | - Bernhard Hirt
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Tübingen, Germany
| | - Corinna Gleiser
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Tübingen, Germany
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23
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Wittekindt OH. Tight junctions in pulmonary epithelia during lung inflammation. Pflugers Arch 2016; 469:135-147. [PMID: 27921210 PMCID: PMC5203840 DOI: 10.1007/s00424-016-1917-3] [Citation(s) in RCA: 136] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 11/23/2016] [Accepted: 11/27/2016] [Indexed: 12/31/2022]
Abstract
Inflammatory lung diseases like asthma bronchiale, chronic obstructive pulmonary disease and allergic airway inflammation are widespread public diseases that constitute an enormous burden to the health systems. Mainly classified as inflammatory diseases, the treatment focuses on strategies interfering with local inflammatory responses by the immune system. Inflammatory lung diseases predispose patients to severe lung failures like alveolar oedema, respiratory distress syndrome and acute lung injury. These life-threatening syndromes are caused by increased permeability of the alveolar and airway epithelium and exudate formation. However, the mechanism underlying epithelium barrier breakdown in the lung during inflammation is elusive. This review emphasises the role of the tight junction of the airway epithelium as the predominating structure conferring epithelial tightness and preventing exudate formation and the impact of inflammatory perturbations on their function.
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Affiliation(s)
- Oliver H Wittekindt
- Institute of General Physiology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
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24
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Porat‐Shliom N, Tietgens AJ, Van Itallie CM, Vitale‐Cross L, Jarnik M, Harding OJ, Anderson JM, Gutkind JS, Weigert R, Arias IM. Liver kinase B1 regulates hepatocellular tight junction distribution and function in vivo. Hepatology 2016; 64:1317-29. [PMID: 27396550 PMCID: PMC5033699 DOI: 10.1002/hep.28724] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/28/2016] [Accepted: 06/30/2016] [Indexed: 12/12/2022]
Abstract
UNLABELLED Liver kinase B1 (LKB1) and its downstream effector AMP-activated protein kinase (AMPK) play critical roles in polarity establishment by regulating membrane trafficking and energy metabolism. In collagen sandwich-cultured hepatocytes, loss of LKB1 or AMPK impaired apical ABCB11 (Bsep) trafficking and bile canalicular formation. In the present study, we used liver-specific (albumin-Cre) LKB1 knockout mice (LKB1(-/-) ) to investigate the role of LKB1 in the maintenance of functional tight junction (TJ) in vivo. Transmission electron microscopy examination revealed that hepatocyte apical membrane with microvilli substantially extended into the basolateral domain of LKB1(-/-) livers. Immunofluorescence studies revealed that loss of LKB1 led to longer and wider canalicular structures correlating with mislocalization of the junctional protein, cingulin. To test junctional function, we used intravital microscopy to quantify the transport kinetics of 6-carboxyfluorescein diacetate (6-CFDA), which is processed in hepatocytes into its fluorescent derivative 6-carboxyfluorescein (6-CF) and secreted into the canaliculi. In LKB1(-/-) mice, 6-CF remained largely in hepatocytes, canalicular secretion was delayed, and 6-CF appeared in the blood. To test whether 6-CF was transported through permeable TJ, we intravenously injected low molecular weight (3 kDa) dextran in combination with 6-CFDA. In wild-type mice, 3 kDa dextran remained in the vasculature, whereas it rapidly appeared in the abnormal bile canaliculi in LKB1(-/-) mice, confirming that junctional disruption resulted in paracellular exchange between the blood stream and the bile canaliculus. CONCLUSION LKB1 plays a critical role in regulating the maintenance of TJ and paracellular permeability, which may explain how various drugs, chemicals, and metabolic states that inhibit the LKB1/AMPK pathway result in cholestasis. (Hepatology 2016;64:1317-1329).
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Affiliation(s)
- Natalie Porat‐Shliom
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial ResearchNational Institutes of HealthBethesdaMD,Laboratory of Cellular and Molecular Biology, National Cancer InstituteNational Institutes of HealthBethesdaMD
| | - Amber J. Tietgens
- Laboratory of Tight Junction Structure and FunctionNational Heart, Lung, and Blood InstituteBethesdaMD
| | - Christina M. Van Itallie
- Laboratory of Tight Junction Structure and FunctionNational Heart, Lung, and Blood InstituteBethesdaMD
| | - Lynn Vitale‐Cross
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial ResearchNational Institutes of HealthBethesdaMD
| | - Michal Jarnik
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMD
| | - Olivia J. Harding
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial ResearchNational Institutes of HealthBethesdaMD
| | - James M. Anderson
- Laboratory of Tight Junction Structure and FunctionNational Heart, Lung, and Blood InstituteBethesdaMD
| | - J. Silvio Gutkind
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial ResearchNational Institutes of HealthBethesdaMD,Present address: University of California, San Diego, Moores Cancer CenterLa JollaCA92093
| | - Roberto Weigert
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial ResearchNational Institutes of HealthBethesdaMD,Laboratory of Cellular and Molecular Biology, National Cancer InstituteNational Institutes of HealthBethesdaMD
| | - Irwin M. Arias
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMD
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25
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Kobayashi K, Tsugami Y, Matsunaga K, Oyama S, Kuki C, Kumura H. Prolactin and glucocorticoid signaling induces lactation-specific tight junctions concurrent with β-casein expression in mammary epithelial cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2006-16. [DOI: 10.1016/j.bbamcr.2016.04.023] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 12/22/2022]
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26
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Baker OJ. Current trends in salivary gland tight junctions. Tissue Barriers 2016; 4:e1162348. [PMID: 27583188 DOI: 10.1080/21688370.2016.1162348] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 02/28/2016] [Accepted: 03/01/2016] [Indexed: 12/21/2022] Open
Abstract
Tight junctions form a continuous intercellular barrier between epithelial cells that is required to separate tissue spaces and regulate selective movement of solutes across the epithelium. They are composed of strands containing integral membrane proteins (e.g., claudins, occludin and tricellulin, junctional adhesion molecules and the coxsackie adenovirus receptor). These proteins are anchored to the cytoskeleton via scaffolding proteins such as ZO-1 and ZO-2. In salivary glands, tight junctions are involved in polarized saliva secretion and barrier maintenance between the extracellular environment and the glandular lumen. This review seeks to provide an overview of what is currently known, as well as the major questions and future research directions, regarding tight junction expression, organization and function within salivary glands.
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Affiliation(s)
- Olga J Baker
- School of Dentistry, University of Utah , Salt Lake City, UT, USA
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27
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Hu Z, Hu J, Shen WJ, Kraemer FB, Azhar S. A Novel Role of Salt-Inducible Kinase 1 (SIK1) in the Post-Translational Regulation of Scavenger Receptor Class B Type 1 Activity. Biochemistry 2015; 54:6917-30. [PMID: 26567857 DOI: 10.1021/acs.biochem.5b00147] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Salt-inducible kinase 1 (SIK1) is a serine/threonine kinase that belongs to the stress- and energy-sensing AMPK family of kinases. SIK1 expression is rapidly induced in Y1 adrenal cells in response to ACTH via the cAMP-PKA signaling cascade, and it has been suggested that an increased level of SIK1 expression inhibits adrenal steroidogenesis by repressing the cAMP-dependent transcription of steroidogenic proteins, CYP11A1 and StAR, by attenuating CREB transcriptional activity. Here we show that SIK1 stimulates adrenal steroidogenesis by modulating the selective HDL-CE transport activity of SR-B1. Overexpression of SIK1 increases cAMP-stimulated and SR-B1-mediated selective HDL-BODIPY-CE uptake in cell lines without impacting SR-B1 protein levels, whereas knockdown of SIK1 attenuated cAMP-stimulated selective HDL-BODIPY-CE uptake. SIK1 forms a complex with SR-B1 by interacting with its cytoplasmic C-terminal domain, and in vitro kinase activity measurements indicate that SIK1 can phosphorylate the C-terminal domain of SR-B1. Among potential phosphorylation sites, SIK1-catalyzed phosphorylation of Ser496 is critical for SIK1 stimulation of the selective CE transport activity of SR-B1. Mutational studies further demonstrated that both the intact catalytic activity of SIK1 and its PKA-catalyzed phosphorylation are essential for SIK1 stimulation of SR-B1 activity. Finally, overexpression of SIK1 caused time-dependent increases in SR-B1-mediated and HDL-supported steroid production in Y1 cells; however, these effects were lost with knockdown of SR-B1. Taken together, these studies establish a role for SIK1 in the positive regulation of selective HDL-CE transport function of SR-B1 and steroidogenesis and suggest a potential mechanism for SIK1 signaling in modulating SR-B1-mediated selective CE uptake and associated steroidogenesis.
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Affiliation(s)
- Zhigang Hu
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System , Palo Alto, California 94304, United States
| | - Jie Hu
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System , Palo Alto, California 94304, United States
| | - Wen-Jun Shen
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System , Palo Alto, California 94304, United States
| | - Fredric B Kraemer
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System , Palo Alto, California 94304, United States
| | - Salman Azhar
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System , Palo Alto, California 94304, United States
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28
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Mei M, Xiang RL, Cong X, Zhang Y, Li J, Yi X, Park K, Han JY, Wu LL, Yu GY. Claudin-3 is required for modulation of paracellular permeability by TNF-α through ERK1/2/slug signaling axis in submandibular gland. Cell Signal 2015; 27:1915-27. [PMID: 26148935 DOI: 10.1016/j.cellsig.2015.07.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/01/2015] [Indexed: 02/07/2023]
Abstract
TNF-α plays an important role in the pathogenesis of salivary inflammatory diseases. Salivary dysfunction, which leads to impaired saliva secretion, can be caused by TNF-α-induced disrupted epithelial barrier. However, the signaling mechanism involved in TNF-α-modulated tight junction barrier in salivary gland remains unclear. Here, we found that TNF-α reduced transepithelial resistance (TER) and increased FITC-dextran flux in a rat submandibular cell line SMG-C6. Claudin (Cln)-3 was selectively downregulated and disrupted by TNF-α, whereas Cln-1, Cln-4, and β-catenin were not affected. Overexpression of Cln-3 retained and Cln-3 knockdown abolished the TNF-α-induced alterations. Moreover, TNF-α increased extracellular signal-regulated kinase (ERK1/2) phosphorylation and the expression of transcriptional factor slug. ERK1/2 kinase inhibitor PD98059 abrogated TNF-α-induced increase in paracellular permeability, alterations of Cln-3, and elevation of slug. Overexpression of slug decreased and slug knockdown increased Cln-3 expression. In addition, slug bind to the E-box elements of Cln-3 promoter in TNF-α-treated cells, and this response was blocked by PD98059. Furthermore, TNF-α decreased Cln-3 expression and increased slug content in cultured human submandibular gland. Taken together, our data suggest that Cln-3 plays a vital role in TNF-α-modulated paracellular permeability in submandibular epithelium and ERK1/2/slug signaling axis is involved in alteration of Cln-3 redistribution and downregulation.
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Affiliation(s)
- Mei Mei
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing 100081, China
| | - Ruo-Lan Xiang
- Department of Physiology and Pathophysiology, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China
| | - Xin Cong
- Department of Physiology and Pathophysiology, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China
| | - Yan Zhang
- Department of Physiology and Pathophysiology, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China
| | - Jing Li
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing 100081, China
| | - Xia Yi
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center and Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Beijing 100191, China
| | - Kyungpyo Park
- Department of Physiology, School of Dentistry, Seoul National University, Seoul 110-749, South Korea
| | - Jing-Yan Han
- Department of Integration of Chinese and Western Medicine, Peking University Health Science Center, Beijing 100191, China
| | - Li-Ling Wu
- Department of Physiology and Pathophysiology, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China.
| | - Guang-Yan Yu
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing 100081, China.
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