1
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Brabec T, Vobořil M, Schierová D, Valter E, Šplíchalová I, Dobeš J, Březina J, Dobešová M, Aidarova A, Jakubec M, Manning J, Blumberg R, Waisman A, Kolář M, Kubovčiak J, Šrůtková D, Hudcovic T, Schwarzer M, Froňková E, Pinkasová T, Jabandžiev P, Filipp D. IL-17-driven induction of Paneth cell antimicrobial functions protects the host from microbiota dysbiosis and inflammation in the ileum. Mucosal Immunol 2023; 16:373-385. [PMID: 36739089 DOI: 10.1016/j.mucimm.2023.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 01/11/2023] [Indexed: 02/05/2023]
Abstract
Interleukin (IL)-17 protects epithelial barriers by inducing the secretion of antimicrobial peptides. However, the effect of IL-17 on Paneth cells (PCs), the major producers of antimicrobial peptides in the small intestine, is unclear. Here, we show that the targeted ablation of the IL-17 receptor (IL-17R) in PCs disrupts their antimicrobial functions and decreases the frequency of ileal PCs. These changes become more pronounced after colonization with IL-17 inducing segmented filamentous bacteria. Mice with PCs that lack IL-17R show an increased inflammatory transcriptional profile in the ileum along with the severity of experimentally induced ileitis. These changes are associated with a decrease in the diversity of gut microbiota that induces a severe ileum pathology upon transfer to genetically susceptible mice, which can be prevented by the systemic administration of IL-17a/f in microbiota recipients. In an exploratory analysis of a small cohort of pediatric patients with Crohn's disease, we have found that a portion of these patients exhibits a low number of lysozyme-expressing ileal PCs and a high ileitis severity score, resembling the phenotype of mice with IL-17R-deficient PCs. Our study identifies IL-17R-dependent signaling in PCs as an important mechanism that maintains ileal homeostasis through the prevention of dysbiosis.
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Affiliation(s)
- Tomáš Brabec
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic; Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Matouš Vobořil
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Dagmar Schierová
- Laboratory of Anaerobic Microbiology, Institute of Animal Physiology and Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Evgeny Valter
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Iva Šplíchalová
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Dobeš
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jiří Březina
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martina Dobešová
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Aigerim Aidarova
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Jakubec
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jasper Manning
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Richard Blumberg
- Brigham and Women's Hospital, Gastroenterology Division, Boston, USA
| | - Ari Waisman
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Michal Kolář
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Kubovčiak
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Dagmar Šrůtková
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - Tomáš Hudcovic
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - Martin Schwarzer
- Laboratory of Gnotobiology, Institute of Microbiology of the Czech Academy of Sciences, Novy Hradek, Czech Republic
| | - Eva Froňková
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Tereza Pinkasová
- Department of Pediatric, University Hospital Brno, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Petr Jabandžiev
- Department of Pediatric, University Hospital Brno, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Dominik Filipp
- Laboratory of Immunobiology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic.
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Richard N, Savoye G, Leboutte M, Amamou A, Ghosh S, Marion-Letellier R. Crohn’s disease: Why the ileum? World J Gastroenterol 2023; 29:3222-3240. [PMID: 37377591 PMCID: PMC10292140 DOI: 10.3748/wjg.v29.i21.3222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/23/2023] [Accepted: 05/08/2023] [Indexed: 06/01/2023] Open
Abstract
Crohn’s disease (CD) is an inflammatory bowel disease characterized by immune-mediated flares affecting any region of the intestine alternating with remission periods. In CD, the ileum is frequently affected and about one third of patients presents with a pure ileal type. Moreover, the ileal type of CD presents epidemiological specificities like a younger age at onset and often a strong link with smoking and genetic susceptibility genes. Most of these genes are associated with Paneth cell dysfunction, a cell type found in the intestinal crypts of the ileum. Besides, a Western-type diet is associated in epidemiological studies with CD onset and increasing evidence shows that diet can modulate the composition of bile acids and gut microbiota, which in turn modulates the susceptibility of the ileum to inflammation. Thus, the interplay between environmental factors and the histological and anatomical features of the ileum is thought to explain the specific transcriptome profile observed in CD ileitis. Indeed, both immune response and cellular healing processes harbour differences between ileal and non-ileal CD. Taken together, these findings advocate for a dedicated therapeutic approach to managing ileal CD. Currently, interventional pharmacological studies have failed to clearly demonstrate distinct response profiles according to disease site. However, the high rate of stricturing disease in ileal CD requires the identification of new therapeutic targets to significantly change the natural history of this debilitating disease.
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Affiliation(s)
- Nicolas Richard
- University of Rouen Normandie, INSERM, ADEN UMR 1073, Nutrition, Inflammation and Microbiota-Gut-Brain Axis, Rouen F-76000, France
- CHU Rouen, Department of Gastroenterology, Rouen University Hospital-Charles Nicolle, Rouen F-76000, France
- Institute for Research and Innovation in Biomedicine, University of Rouen Normandie, Rouen F-76000, France
| | - Guillaume Savoye
- University of Rouen Normandie, INSERM, ADEN UMR 1073, Nutrition, Inflammation and Microbiota-Gut-Brain Axis, Rouen F-76000, France
- CHU Rouen, Department of Gastroenterology, Rouen University Hospital-Charles Nicolle, Rouen F-76000, France
- Institute for Research and Innovation in Biomedicine, University of Rouen Normandie, Rouen F-76000, France
| | - Mathilde Leboutte
- University of Rouen Normandie, INSERM, ADEN UMR 1073, Nutrition, Inflammation and Microbiota-Gut-Brain Axis, Rouen F-76000, France
- Institute for Research and Innovation in Biomedicine, University of Rouen Normandie, Rouen F-76000, France
| | - Asma Amamou
- APC Microbiome Ireland, Biosciences Building, University College Cork, Cork T12 YT20, Ireland
| | - Subrata Ghosh
- APC Microbiome Ireland, Biosciences Building, University College Cork, Cork T12 YT20, Ireland
| | - Rachel Marion-Letellier
- University of Rouen Normandie, INSERM, ADEN UMR 1073, Nutrition, Inflammation and Microbiota-Gut-Brain Axis, Rouen F-76000, France
- Institute for Research and Innovation in Biomedicine, University of Rouen Normandie, Rouen F-76000, France
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Nakahara E, Yamamoto KS, Ogura H, Aoki T, Utsugisawa T, Azuma K, Akagawa H, Watanabe K, Muraoka M, Nakamura F, Kamei M, Tatebayashi K, Shinozuka J, Yamane T, Hibino M, Katsura Y, Nakano-Akamatsu S, Kadowaki N, Maru Y, Ito E, Ohga S, Yagasaki H, Morioka I, Yamamoto T, Kanno H. Variant spectrum of PIEZO1 and KCNN4 in Japanese patients with dehydrated hereditary stomatocytosis. Hum Genome Var 2023; 10:8. [PMID: 36864026 PMCID: PMC9981561 DOI: 10.1038/s41439-023-00235-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 01/26/2023] [Accepted: 02/01/2023] [Indexed: 03/04/2023] Open
Abstract
Hereditary stomatocytosis (HSt) is a type of congenital hemolytic anemia caused by abnormally increased cation permeability of erythrocyte membranes. Dehydrated HSt (DHSt) is the most common subtype of HSt and is diagnosed based on clinical and laboratory findings related to erythrocytes. PIEZO1 and KCNN4 have been recognized as causative genes, and many related variants have been reported. We analyzed the genomic background of 23 patients from 20 Japanese families suspected of having DHSt using a target capture sequence and identified pathogenic/likely pathogenic variants of PIEZO1 or KCNN4 in 12 families.
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Affiliation(s)
- Erina Nakahara
- Department of Transfusion Medicine and Cell Processing, Tokyo Women's Medical University, Tokyo, Japan
- Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan
| | - Keiko Shimojima Yamamoto
- Department of Transfusion Medicine and Cell Processing, Tokyo Women's Medical University, Tokyo, Japan.
- Institute for Comprehensive Medical Sciences, Tokyo Women's Medical University, Tokyo, Japan.
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan.
| | - Hiromi Ogura
- Department of Transfusion Medicine and Cell Processing, Tokyo Women's Medical University, Tokyo, Japan
| | - Takako Aoki
- Department of Transfusion Medicine and Cell Processing, Tokyo Women's Medical University, Tokyo, Japan
| | - Taiju Utsugisawa
- Department of Transfusion Medicine and Cell Processing, Tokyo Women's Medical University, Tokyo, Japan
| | - Kenko Azuma
- Institute for Comprehensive Medical Sciences, Tokyo Women's Medical University, Tokyo, Japan
| | - Hiroyuki Akagawa
- Institute for Comprehensive Medical Sciences, Tokyo Women's Medical University, Tokyo, Japan
| | - Kenichiro Watanabe
- Department of Hematology and Oncology, Shizuoka Children's Hospital, Shizuoka, Japan
| | - Michiko Muraoka
- Department of Pediatrics, Fukuyama Medical Center, Okayama, Japan
| | - Fumihiko Nakamura
- Department of Laboratory Medicine, Nara Prefecture General Medical Center, Nara, Japan
| | - Michi Kamei
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Koji Tatebayashi
- Department of Neonatology, Gifu Prefectural General Medical Center, Gifu, Japan
| | - Jun Shinozuka
- Department of Pediatrics, Uji-Tokushukai Medical Center, Kyoto, Japan
| | - Takahisa Yamane
- Department of Hematology, Osaka City General Hospital, Osaka, Japan
| | - Makoto Hibino
- Department of Respiratory Medicine, Shonan Fujisawa Tokushukai Hospital, Fujisawa, Kanagawa, Japan
| | - Yoshiya Katsura
- Department of Metabolism and Endocrinology, Tokyo Medical University Ibaraki Medical Center, Ibaraki, Japan
| | | | - Norimitsu Kadowaki
- Department of Internal Medicine, Division of Hematology, Rheumatology and Respiratory Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Yoshiro Maru
- Department of Pharmacology, Tokyo Women's Medical University, Tokyo, Japan
| | - Etsuro Ito
- Department of Pediatrics, Hirosaki University Graduate School of Medicine, Aomori, Japan
| | - Shouichi Ohga
- Department of Pediatrics, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Hiroshi Yagasaki
- Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan
| | - Ichiro Morioka
- Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan
| | - Toshiyuki Yamamoto
- Institute for Comprehensive Medical Sciences, Tokyo Women's Medical University, Tokyo, Japan
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan
| | - Hitoshi Kanno
- Department of Transfusion Medicine and Cell Processing, Tokyo Women's Medical University, Tokyo, Japan
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4
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Feng J, Xie Z, Hu H. Ion channel regulation of gut immunity. J Gen Physiol 2022; 155:213734. [PMID: 36459135 PMCID: PMC9723512 DOI: 10.1085/jgp.202113042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 08/15/2022] [Accepted: 11/17/2022] [Indexed: 12/03/2022] Open
Abstract
Mounting evidence indicates that gastrointestinal (GI) homeostasis hinges on communications among many cellular networks including the intestinal epithelium, the immune system, and both intrinsic and extrinsic nerves innervating the gut. The GI tract, especially the colon, is the home base for gut microbiome which dynamically regulates immune function. The gut's immune system also provides an effective defense against harmful pathogens entering the GI tract while maintaining immune homeostasis to avoid exaggerated immune reaction to innocuous food and commensal antigens which are important causes of inflammatory disorders such as coeliac disease and inflammatory bowel diseases (IBD). Various ion channels have been detected in multiple cell types throughout the GI tract. By regulating membrane properties and intracellular biochemical signaling, ion channels play a critical role in synchronized signaling among diverse cellular components in the gut that orchestrates the GI immune response. This work focuses on the role of ion channels in immune cells, non-immune resident cells, and neuroimmune interactions in the gut at the steady state and pathological conditions. Understanding the cellular and molecular basis of ion channel signaling in these immune-related pathways and initial testing of pharmacological intervention will facilitate the development of ion channel-based therapeutic approaches for the treatment of intestinal inflammation.
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Affiliation(s)
- Jing Feng
- Department of Anesthesiology, The Center for the Study of Itch and Sensory Disorders, Washington University School of Medicine, St. Louis, MO,Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, China,Correspondence to Jing Feng:
| | - Zili Xie
- Department of Anesthesiology, The Center for the Study of Itch and Sensory Disorders, Washington University School of Medicine, St. Louis, MO
| | - Hongzhen Hu
- Department of Anesthesiology, The Center for the Study of Itch and Sensory Disorders, Washington University School of Medicine, St. Louis, MO,Hongzhen Hu:
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Cosme D, Soares-da-Silva P, Magro F. Effect of Toll-like receptor-2, -4, -5, -7, and NOD2 stimulation on potassium channel conductance in intestinal epithelial cells. Am J Physiol Gastrointest Liver Physiol 2022; 323:G410-G419. [PMID: 36040119 DOI: 10.1152/ajpgi.00139.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Disproportionate activation of pattern recognition receptors plays a role in inflammatory bowel disease (IBD) pathophysiology. Diarrhea is a hallmark symptom of IBD, resulting at least in part from an electrolyte imbalance that may be caused by changes in potassium channel activity. We evaluated the impact of Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain 2 (NOD2) stimulation on potassium conductance of the basolateral membrane in human intestinal epithelial cells (IECs) and the role of potassium channels through electrophysiological assays under short-circuit current in Ussing chambers. TLRs and NOD2 were stimulated using specific agonists, and potassium channels were selectively blocked using triarylmethane-34 (TRAM-34), adenylyl-imidodiphosphate (AMP-PNP), and BaCl2. Potassium conductance of the basolateral membrane decreased upon activation of TLR2, TLR4, and TLR7 in T84 cells (means ± SE, -11.2 ± 4.5, -40.4 ± 7.2, and -19.4 ± 5.9, respectively) and in Caco-2 cells (-13.1 ± 5.7, -55.7 ± 7.4, and -29.1 ± 7.2, respectively). In contrast, activation of TLR5 and NOD2 increased basolateral potassium conductance, both in T84 cells (18.0 ± 4.1 and 18.4 ± 2.8, respectively) and in Caco-2 cells (21.2 ± 8.4 and 16.0 ± 3.6, respectively). TRAM-34 and AMP-PNP induced a decrease in basolateral potassium conductance upon TLR4 stimulation in both cell lines. Both KCa3.1- and Kir6-channels appear to be important mediators of this effect in IECs and could be potential targets for therapeutic agent development.NEW & NOTEWORTHY This study highlights that PRRs stimulation directly influences K+-channel conductance in IECs. TLR-2, -4, -7 stimulation decreased K+ conductance, whereas TLR5 and NOD2 stimulation had the opposite effect, leading to an increase of it instead. This study reports for the first time that KCa3.1- and Kir6-channels play a role in K+ transport pathways triggered by TLR4 stimulation. These findings suggest that KCa3.1- and Kir6-channels modulation may be a potential target for new therapeutic agents in IBD.
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Affiliation(s)
- Dina Cosme
- Unit of Pharmacology and Therapeutics, Department of Biomedicine, Faculty of Medicine, University of Porto, Porto, Portugal.,MedInUP, Center for Drug Discovery and Innovative Medicines, Porto, Portugal
| | - Patrício Soares-da-Silva
- Unit of Pharmacology and Therapeutics, Department of Biomedicine, Faculty of Medicine, University of Porto, Porto, Portugal.,MedInUP, Center for Drug Discovery and Innovative Medicines, Porto, Portugal
| | - Fernando Magro
- Unit of Pharmacology and Therapeutics, Department of Biomedicine, Faculty of Medicine, University of Porto, Porto, Portugal.,Department of Gastroenterology, São João Hospital University Centre, Porto, Portugal.,Center for Health Technology and Services Research, Porto, Portugal.,Clinical Pharmacology Unit, São João Hospital University Centre, Porto, Portugal.,Portuguese Inflammatory Bowel Disease Group, Porto, Portugal
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6
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Chen S, Su X, Mo Z. KCNN4 is a Potential Biomarker for Predicting Cancer Prognosis and an Essential Molecule that Remodels Various Components in the Tumor Microenvironment: A Pan-Cancer Study. Front Mol Biosci 2022; 9:812815. [PMID: 35720112 PMCID: PMC9205469 DOI: 10.3389/fmolb.2022.812815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 05/02/2022] [Indexed: 12/15/2022] Open
Abstract
Objectives: Potassium Calcium-Activated Channel Subfamily N Member 4 (KCNN4) is a member of the KCNN family. Studies have revealed that KCNN4 is implicated in various physiological processes as well as promotes the malignant phenotypes of cancer cells. However, little is known about its associations with survival outcomes across varying cancer types. Methods: Herein, we systematically explored the prognostic value of KCNN4 in the pan-cancer dataset retrieved from multiple databases. Next, we performed correlation analysis of KCNN4 expression with tumor mutational burden (TMB) and microsatellite instability (MSI), and immune checkpoint genes (ICGs) to assess its potential as a predictor of immunotherapy efficacy. Afterwards, patients were divided into increased-risk group and decreased-risk group based on the contrasting survival outcomes in various cancer types. Furthermore, the underlying mechanisms of the distinctive effects were analyzed using ESTIMATE, CIBERSORT algorithms, and Gene Set Enrichment Analysis (GSEA) analysis. Results: KCNN4 expression levels were aberrant in transcriptomic and proteomic levels between cancer and normal control tissues in pan-cancer datasets, further survival analysis elucidated that KCNN4 expression was correlated to multiple survival data, and clinical annotations. Besides, KCNN4 expression was correlated to TMB and MSI levels in 14 types and 12 types of pan-cancers, respectively. Meanwhile, different types of cancer have specific tumor-infiltrating immune cell (TICs) profiles. Conclusions: Our results revealed that KCNN4 could be an essential biomarker for remodeling components in the tumor microenvironment (TME), and a robust indicator for predicting prognosis as well as immunotherapy response in pan-cancer patients.
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Affiliation(s)
- Shaohua Chen
- Department of Urology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
- Guangxi Key Laboratory for Genomic and Personalized Medicine, Center for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China
| | - Xiaotao Su
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zengnan Mo
- Department of Urology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
- Guangxi Key Laboratory for Genomic and Personalized Medicine, Center for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, China
- *Correspondence: Zengnan Mo,
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7
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Han YM, Gao H, Hua RX, Liang C, Guo YX, Shang HW, Lu X, Xu JD. Paneth cells and intestinal health. Shijie Huaren Xiaohua Zazhi 2021; 29:1362-1372. [DOI: 10.11569/wcjd.v29.i23.1362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Paneth cells (PC) are a group of secretory cells derived from intestinal stem cells (ISC) and colonized in the bottom of the small intestinal crypt. As an important "guardian" of intestinal health, PC can not only secrete a variety of antibacterial peptides and cytokines to regulate intestinal homeostasis and participate in immune responses, but also release growth factors to support the stem cell niche and regulate their proliferation and differentiation. Of particular concern, as a static stem cell pool, PC can acquire a stem cell-like transcriptome after the injury of intestinal tissue so as to promote regeneration and repair the damaged intestinal tissue. Particularly, PC are closely related to a number of diseases that affect intestinal health, such as inflammatory bowel disease (IBD) and colorectal cancer (CRC). The research of biological functions of PC may provide ideas for the treatment of these diseases. In summary, the role of PC in maintaining intestinal health should not be underestimated.
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Affiliation(s)
- Yi-Min Han
- 2019 Oral Medicine, Capital Medical University, Beijing 100069, China
| | - Han Gao
- Department of Physiology and Pathophysiology, Capital Medical University, Beijing 100069, China
| | - Rong-Xuan Hua
- 2020 Clinical Medicine of "5+3" Program, Capital Medical University, Beijing 100069, China
| | - Chen Liang
- Clinical Medicine, Capital Medical University, Beijing 100069, China
| | - Yue-Xin Guo
- 2019 Oral Medicine of "5+3" Program, Capital Medical University, Beijing 100069, China
| | - Hong-Wei Shang
- Experimental Teaching Center of Basic Medical Morphology, Capital Medical University, Beijing 100069, China
| | - Xin Lu
- Experimental Teaching Center of Basic Medical Morphology, Capital Medical University, Beijing 100069, China
| | - Jing-Dong Xu
- Department of Physiology and Pathophysiology, Capital Medical University, Beijing 100069, China
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8
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Deng Z, Zhao Y, Ma Z, Zhang M, Wang H, Yi Z, Tuo B, Li T, Liu X. Pathophysiological role of ion channels and transporters in gastrointestinal mucosal diseases. Cell Mol Life Sci 2021; 78:8109-25. [PMID: 34778915 DOI: 10.1007/s00018-021-04011-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 09/10/2021] [Accepted: 10/23/2021] [Indexed: 11/13/2022]
Abstract
The incidence of gastrointestinal (GI) mucosal diseases, including various types of gastritis, ulcers, inflammatory bowel disease and GI cancer, is increasing. Therefore, it is necessary to identify new therapeutic targets. Ion channels/transporters are located on cell membranes, and tight junctions (TJs) affect acid–base balance, the mucus layer, permeability, the microbiota and mucosal blood flow, which are essential for maintaining GI mucosal integrity. As ion channel/transporter dysfunction results in various GI mucosal diseases, this review focuses on understanding the contribution of ion channels/transporters to protecting the GI mucosal barrier and the relationship between GI mucosal disease and ion channels/transporters, including Cl−/HCO3− exchangers, Cl− channels, aquaporins, Na+/H+ exchangers, and K+ channels. Here, we provide novel prospects for the treatment of GI mucosal diseases.
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9
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Pierre N, Salée C, Vieujean S, Bequet E, Merli AM, Siegmund B, Meuwis MA, Louis E. Review article: distinctions between ileal and colonic Crohn's disease: from physiology to pathology. Aliment Pharmacol Ther 2021; 54:779-791. [PMID: 34297423 DOI: 10.1111/apt.16536] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 05/15/2021] [Accepted: 07/05/2021] [Indexed: 12/19/2022]
Abstract
BACKGROUND Ileal and colonic Crohn's disease seem to be two separate entities. AIMS To describe the main physiological distinctions between the small and the large intestine and to analyse the differences between ileal and colonic Crohn's disease. METHODS The relevant literature was critically examined and synthesised. RESULTS The small and large intestine have fundamental distinctions (anatomy, cellular populations, immune defence, microbiota). The differences between ileal and colonic Crohn's disease are highlighted by a heterogeneous body of evidence including clinical features (natural history of the disease, efficacy of treatments, and monitoring), epidemiological data (smoking status, age, gender) and biological data (genetics, microbiota, immunity, mesenteric fat). However, the contribution of these factors to disease location remains poorly understood. CONCLUSION The classification of ileal and colonic Crohn's disease as distinct subphenotypes is well supported by the literature. Understanding of these differences could be exploited to develop more individualised patient care.
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Affiliation(s)
- Nicolas Pierre
- Laboratory of Translational Gastroenterology, GIGA-Institute, University of Liège, Liège, Belgium
| | - Catherine Salée
- Laboratory of Translational Gastroenterology, GIGA-Institute, University of Liège, Liège, Belgium
| | - Sophie Vieujean
- Laboratory of Translational Gastroenterology, GIGA-Institute, University of Liège, Liège, Belgium.,Hepato-Gastroenterology and Digestive Oncology Department, Liège University Hospital, Liège, Belgium
| | - Emeline Bequet
- Laboratory of Translational Gastroenterology, GIGA-Institute, University of Liège, Liège, Belgium.,Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Liège University Hospital, Liège, Belgium
| | - Angela-Maria Merli
- Laboratory of Translational Gastroenterology, GIGA-Institute, University of Liège, Liège, Belgium
| | - Britta Siegmund
- Division of Gastroenterology, Infectiology and Rheumatology, Medical Department, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Marie-Alice Meuwis
- Laboratory of Translational Gastroenterology, GIGA-Institute, University of Liège, Liège, Belgium.,Hepato-Gastroenterology and Digestive Oncology Department, Liège University Hospital, Liège, Belgium
| | - Edouard Louis
- Laboratory of Translational Gastroenterology, GIGA-Institute, University of Liège, Liège, Belgium.,Hepato-Gastroenterology and Digestive Oncology Department, Liège University Hospital, Liège, Belgium
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10
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Xu P, Mo X, Xia R, Jiang L, Zhang C, Xu H, Sun Q, Zhou G, Zhang Y, Wang Y, Xia H. KCNN4 promotes the progression of lung adenocarcinoma by activating the AKT and ERK signaling pathways. Cancer Biomark 2021; 31:187-201. [PMID: 33896824 DOI: 10.3233/cbm-201045] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Potassium channels, encoded by more than seventy genes, are cell excitability transmembrane proteins and become evident to play essential roles in tumor biology. OBJECTIVE The deregulation of potassium channel genes has been related to cancer development and patient prognosis. The objective of this study is to understand the role of potassium channels in lung cancer. METHODS We examined all potassium channel genes and identified that KCNN4 is the most significantly overexpressed one in lung adenocarcinoma. The role and mechanism of KCNN4 in lung adenocarcinoma were further investigated by in vitro cell and molecular assay and in vivo mouse xenograft models. RESULTS We revealed that the silencing of KCNN4 significantly inhibits cell proliferation, migration, invasion, and tumorigenicity of lung adenocarcinoma. Further studies showed that knockdown of KCNN4 promotes cell apoptosis, induces cell cycle arrested in the S phase, and is associated with the epithelial to mesenchymal transition (EMT) process. Most importantly, we demonstrated that KCNN4 regulates the progression of lung adenocarcinoma through P13K/AKT and MEK/ERK signaling pathways. The use of inhibitors that targeted AKT and ERK also significantly inhibit the proliferation and metastasis of lung adenocarcinoma cells. CONCLUSIONS This study investigated the function and mechanism of KCNN4 in lung adenocarcinoma. On this basis, this means that KCNN4 can be used as a tumor marker for lung adenocarcinoma and is expected to become an important target for a potential drug.
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Affiliation(s)
- Ping Xu
- Department of Pathology, School of Basic Medical Sciences and Sir Run Run Hospital and Key Laboratory of Antibody Technique of National Health Commission, Nanjing Medical University, Nanjing, Jiangsu, China.,Department of Pathology, School of Basic Medical Sciences and Sir Run Run Hospital and Key Laboratory of Antibody Technique of National Health Commission, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xiao Mo
- Department of Pathology, School of Basic Medical Sciences and Sir Run Run Hospital and Key Laboratory of Antibody Technique of National Health Commission, Nanjing Medical University, Nanjing, Jiangsu, China.,Department of Pathology, School of Basic Medical Sciences and Sir Run Run Hospital and Key Laboratory of Antibody Technique of National Health Commission, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ruixue Xia
- Department of Respiratory and Critical Care Medicine, Henan University Huaihe Hospital, Kaifeng, Henan, China.,Department of Pathology, School of Basic Medical Sciences and Sir Run Run Hospital and Key Laboratory of Antibody Technique of National Health Commission, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Long Jiang
- Shanghai Lung Cancer Center, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China.,Department of Pathology, School of Basic Medical Sciences and Sir Run Run Hospital and Key Laboratory of Antibody Technique of National Health Commission, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Chengfei Zhang
- Department of Pathology, School of Basic Medical Sciences and Sir Run Run Hospital and Key Laboratory of Antibody Technique of National Health Commission, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Haojun Xu
- Department of Pathology, School of Basic Medical Sciences and Sir Run Run Hospital and Key Laboratory of Antibody Technique of National Health Commission, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Qi Sun
- Department of Pathology, School of Basic Medical Sciences and Sir Run Run Hospital and Key Laboratory of Antibody Technique of National Health Commission, Nanjing Medical University, Nanjing, Jiangsu, China.,Nanjing Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Guoren Zhou
- Jiangsu Cancer Hospital and the Affiliated Cancer Hospital of Nanjing Medical University and Jiangsu Institute of Cancer Research, Nanjing, Jiangsu, China
| | - Yijie Zhang
- Department of Respiratory and Critical Care Medicine, Henan University Huaihe Hospital, Kaifeng, Henan, China
| | - Yongsheng Wang
- Nanjing Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Hongping Xia
- Department of Pathology, School of Basic Medical Sciences and Sir Run Run Hospital and Key Laboratory of Antibody Technique of National Health Commission, Nanjing Medical University, Nanjing, Jiangsu, China.,Jiangsu Cancer Hospital and the Affiliated Cancer Hospital of Nanjing Medical University and Jiangsu Institute of Cancer Research, Nanjing, Jiangsu, China.,Department of Respiratory and Critical Care Medicine, Henan University Huaihe Hospital, Kaifeng, Henan, China
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11
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Cosme D, Estevinho MM, Rieder F, Magro F. Potassium channels in intestinal epithelial cells and their pharmacological modulation: a systematic review. Am J Physiol Cell Physiol 2020; 320:C520-C546. [PMID: 33326312 DOI: 10.1152/ajpcell.00393.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Several potassium channels (KCs) have been described throughout the gastrointestinal tract. Notwithstanding, their contribution to both physiologic and pathophysiologic conditions, as inflammatory bowel disease (IBD), remains underexplored. Therefore, we aim to systematically review, for the first time, the evidence on the characteristics and modulation of KCs in intestinal epithelial cells (IECs). PubMed, Scopus, and Web of Science were searched to identify studies focusing on KCs and their modulation in IECs. The included studies were assessed using a reporting inclusiveness checklist. From the 745 identified records, 73 met the inclusion criteria; their reporting inclusiveness was moderate-high. Some studies described the physiological role of KCs, while others explored their importance in pathological settings. Globally, in IBD animal models, apical KCa1.1 channels, responsible for luminal secretion, were upregulated. In human colonocytes, basolateral KCa3.1 channels were downregulated. The pharmacological inhibition of K2P and Kv influenced intestinal barrier function, promoting inflammation. Evidence suggests a strong association between KCs expression and secretory mechanisms in human and animal IECs. Further research is warranted to explore the usefulness of KC pharmacological modulation as a therapeutic target.
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Affiliation(s)
- Dina Cosme
- Department of Biomedicine, Unit of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, Porto, Portugal.,MedInUP, Center for Drug Discovery and Innovative Medicines, Porto, Portugal
| | - Maria Manuela Estevinho
- Department of Biomedicine, Unit of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, Porto, Portugal.,Department of Gastroenterology, Centro Hospitalar Vila Nova de Gaia/Espinho, Vila Nova de Gaia, Portugal
| | - Florian Rieder
- Department of Gastroenterology, Hepatology and Nutrition, Digestive Diseases, and Surgery Institute, Cleveland Clinic Foundation, Cleveland, Ohio.,Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Fernando Magro
- Department of Biomedicine, Unit of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, Porto, Portugal.,MedInUP, Center for Drug Discovery and Innovative Medicines, Porto, Portugal.,Department of Gastroenterology, Centro Hospitalar São João, Porto, Portugal
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12
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Abstract
The Paneth cells reside in the small intestine at the bottom of the crypts of Lieberkühn, intermingled with stem cells, and provide a niche for their neighbors by secreting growth and Wnt-factors as well as different antimicrobial peptides including defensins, lysozyme and others. The most abundant are the human Paneth cell α-defensin 5 and 6 that keep the crypt sterile and control the local microbiome. In ileal Crohn's disease various mechanisms including established genetic risk factors contribute to defects in the production and ordered secretion of these peptides. In addition, life-style risk factors for Crohn's disease like tobacco smoking also impact on Paneth cell function. Taken together, current evidence suggest that defective Paneth cells may play the key role in initiating inflammation in ileal, and maybe ileocecal, Crohn's disease by allowing bacterial attachment and invasion.
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Affiliation(s)
- Jan Wehkamp
- University of Tübingen, Medizinische Klinik I, Tübingen, Germany
| | - Eduard F Stange
- University of Tübingen, Medizinische Klinik I, Tübingen, Germany
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13
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Philp AR, Riquelme TT, Millar-Büchner P, González R, Sepúlveda FV, Cid LP, Flores CA. Kcnn4 is a modifier gene of intestinal cystic fibrosis preventing lethality in the Cftr-F508del mouse. Sci Rep 2018; 8:9320. [PMID: 29915289 PMCID: PMC6006244 DOI: 10.1038/s41598-018-27465-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 06/04/2018] [Indexed: 02/07/2023] Open
Abstract
Nearly 70% of cystic fibrosis (CF) patients bear the phenylalanine-508 deletion but disease severity differs greatly, and is not explained by the existence of different mutations in compound heterozygous. Studies demonstrated that genes other than CFTR relate to intestinal disease in humans and CF-mouse. Kcnn4, the gene encoding the calcium-activated potassium channel KCa3.1, important for intestinal secretion, is present in a locus linked with occurrence of intestinal CF-disease in mice and humans. We reasoned that it might be a CF-modifier gene and bred a CF-mouse with Kcnn4 silencing, finding that lethality was almost abolished. Silencing of Kcnn4 did not improve intestinal secretory functions, but rather corrected increased circulating TNF-α level and reduced intestinal mast cell increase. Given the importance of mast cells in intestinal disease additional double mutant CF-animals were tested, one lacking mast cells (C-kitW-sh/W-sh) and Stat6-/- to block IgE production. While mast cell depletion had no effect, silencing Stat6 significantly reduced lethality. Our results show that Kcnn4 is an intestinal CF modifier gene partially acting through a STAT6-dependent mechanism.
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Affiliation(s)
- Amber R Philp
- Centro de Estudios Científicos (CECs), Arturo Prat 514, Valdivia, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Texia T Riquelme
- Centro de Estudios Científicos (CECs), Arturo Prat 514, Valdivia, Chile
| | - Pamela Millar-Büchner
- Centro de Estudios Científicos (CECs), Arturo Prat 514, Valdivia, Chile
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Rodrigo González
- Centro de Estudios Científicos (CECs), Arturo Prat 514, Valdivia, Chile
| | | | - L Pablo Cid
- Centro de Estudios Científicos (CECs), Arturo Prat 514, Valdivia, Chile
| | - Carlos A Flores
- Centro de Estudios Científicos (CECs), Arturo Prat 514, Valdivia, Chile.
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14
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Armbruster NS, Stange EF, Wehkamp J. In the Wnt of Paneth Cells: Immune-Epithelial Crosstalk in Small Intestinal Crohn's Disease. Front Immunol 2017; 8:1204. [PMID: 29018451 PMCID: PMC5622939 DOI: 10.3389/fimmu.2017.01204] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 09/11/2017] [Indexed: 12/27/2022] Open
Abstract
Paneth cells, specialized secretory epithelial cells of the small intestine, play a pivotal role in host defense and regulation of microbiota by producing antimicrobial peptides especially-but not only-the human α-defensin 5 (HD5) and HD6. In small intestinal Crohn's disease (CD) which is an entity of inflammatory bowel diseases, the expression of HD5 and HD6 is specifically compromised leading to a disturbed barrier and change in the microbial community. Different genetically driven but also non-genetic defects associated with small intestinal CD affect different lines of antimicrobial Paneth cell functions. In this review, we focus on the mechanisms and the crosstalk of Paneth cells and bone marrow-derived cells and highlight recent studies about the role of the Wnt signaling pathway in this connection of ileal CD. In summary, different lines of investigations led by us but also now numerous other groups support and reconfirm the proposed classification of this disease entity as Paneth's disease.
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Affiliation(s)
| | - Eduard F Stange
- Internal Medicine I, University Hospital Tübingen, Tübingen, Germany
| | - Jan Wehkamp
- Internal Medicine I, University Hospital Tübingen, Tübingen, Germany
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15
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Abstract
Inflammatory bowel diseases (IBDs) are thought to develop as a result of complex interactions between host genetics, the immune system and the environment including the gut microbiome. Although an improved knowledge of the immunopathogenesis of IBDs has led to great advances in therapy such as the highly effective anti-tumor necrosis factor class of medications, a significant proportion of patients with Crohn's disease and ulcerative colitis do not respond to anti-tumor necrosis factor antibodies. Further understanding of the different immune pathways involved in the genesis of chronic intestinal inflammation is required to help find effective treatments for IBDs. In this review, the role of the mucosal innate and adaptive immune system in IBD is summarized, highlighting new areas of discovery which may hold the key to identifying novel predictive or prognostic biomarkers and new avenues of therapeutic discovery.
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16
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Khalili H, Malik S, Ananthakrishnan AN, Garber JJ, Higuchi LM, Joshi A, Peloquin J, Richter JM, Stewart KO, Curhan GC, Awasthi A, Yajnik V, Chan AT. Identification and Characterization of a Novel Association between Dietary Potassium and Risk of Crohn's Disease and Ulcerative Colitis. Front Immunol 2016; 7:554. [PMID: 28003811 PMCID: PMC5141241 DOI: 10.3389/fimmu.2016.00554] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 11/18/2016] [Indexed: 12/19/2022] Open
Abstract
Background Recent animal studies have identified that dietary salt intake may modify the risk and progression of autoimmune disorders through modulation of the IL-23/TH17 pathway, which is critical in the pathogenesis of ulcerative colitis (UC) and Crohn’s disease (CD). Methods We conducted a prospective study of U.S. women enrolled in the Nurses’ Health Study (NHS) and NHSII who provided detailed and validated information on diet and lifestyle beginning in 1984 in NHS and 1991 in NHSII. We confirmed incident cases of UC and CD reported through 2010 in NHS and 2011 in NHSII. We used Cox proportional hazards models to calculate hazard ratios and 95% confidence intervals. In a case–control study nested within these cohorts, we evaluated the interaction between single nucleotide polymorphisms (SNPs) in genes involved in TH17 pathway and dietary potassium on risk of CD and UC. In a cohort of healthy volunteers, we also assessed the effect of supplemental potassium on development of naïve and memory T cells, differentiated with TGFβ1 or TH17 conditions. Results Among a total of 194,711 women over a follow-up of 3,220,247 person-years, we documented 273 cases of CD and 335 cases of UC. Dietary intake of potassium (Ptrend = 0.005) but not sodium (Ptrend = 0.44) was inversely associated with risk of CD. Although, both dietary potassium and sodium were not significantly associated with risk of UC, there was a suggestion of an inverse association with dietary potassium (Ptrend = 0.08). The association of potassium with risk of CD and UC appeared to be modified by loci involved in the TH17 pathway that have previously been associated with susceptibility to CD, particularly SNP rs7657746 (IL21) (Pinteraction = 0.004 and 0.01, respectively). In vitro, potassium enhanced the expression of Foxp3 in both naïve and memory CD4+ T cells via activating Smad2/3 and inhibiting Smad7 in TH17 cells. Conclusion Dietary potassium is inversely associated with risk of CD with both in vitro and gene–environment interaction data suggesting a potential role for potassium in regulating immune tolerance through its effect on Tregs and TH17 pathway.
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Affiliation(s)
- Hamed Khalili
- Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Clinical and Translational Epidemiology Unit, Massachusetts General Hospital, Boston, MA, USA
| | - Sakshi Malik
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster , Faridabad , India
| | - Ashwin N Ananthakrishnan
- Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Clinical and Translational Epidemiology Unit, Massachusetts General Hospital, Boston, MA, USA
| | - John J Garber
- Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
| | - Leslie M Higuchi
- Division of Gastroenterology and Nutrition, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA
| | - Amit Joshi
- Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Clinical and Translational Epidemiology Unit, Massachusetts General Hospital, Boston, MA, USA
| | - Joanna Peloquin
- Division of Gastroenterology and Hepatology, Johns Hopkins School of Medicine , Baltimore, MD , USA
| | - James M Richter
- Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
| | - Kathleen O Stewart
- Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
| | - Gary C Curhan
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, MA , USA
| | - Amit Awasthi
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster , Faridabad , India
| | - Vijay Yajnik
- Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
| | - Andrew T Chan
- Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Clinical and Translational Epidemiology Unit, Massachusetts General Hospital, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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17
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Magalhães D, Cabral JM, Soares-da-Silva P, Magro F. Role of epithelial ion transports in inflammatory bowel disease. Am J Physiol Gastrointest Liver Physiol 2016; 310:G460-76. [PMID: 26744474 DOI: 10.1152/ajpgi.00369.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 01/02/2016] [Indexed: 02/06/2023]
Abstract
Inflammatory bowel disease (IBD) is a chronic inflammatory disorder with a complex pathogenesis. Diarrhea is a highly prevalent and often debilitating symptom of IBD patients that results, at least in part, from an intestinal hydroelectrolytic imbalance. Evidence suggests that reduced electrolyte absorption is more relevant than increased secretion to this disequilibrium. This systematic review analyses and integrates the current evidence on the roles of epithelial Na(+)-K(+)-ATPase (NKA), Na(+)/H(+) exchangers (NHEs), epithelial Na(+) channels (ENaC), and K(+) channels (KC) in IBD-associated diarrhea. NKA is the key driving force of the transepithelial ionic transport and its activity is decreased in IBD. In addition, the downregulation of apical NHE and ENaC and the upregulation of apical large-conductance KC all contribute to the IBD-associated diarrhea by lowering sodium absorption and/or increasing potassium secretion.
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Affiliation(s)
- Diogo Magalhães
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Porto, Portugal; and MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal
| | - José Miguel Cabral
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Porto, Portugal; and MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal
| | - Patrício Soares-da-Silva
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Porto, Portugal; and MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal
| | - Fernando Magro
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Porto, Portugal; and MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal
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18
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Zhang Z, Liu Z. Paneth cells: the hub for sensing and regulating intestinal flora. Sci China Life Sci 2016; 59:463-7. [PMID: 26842130 DOI: 10.1007/s11427-016-5018-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Accepted: 01/10/2016] [Indexed: 12/23/2022]
Abstract
The complex interplay between symbiotic bacteria and host immunity plays a key role in shaping intestinal homeostasis and maintaining host health. Paneth cells, as one of the major producers of antimicrobial peptides in the intestine under steady-state conditions, play a vital role in regulating intestinal flora. Many studies on inflammatory bowel disease (IBD)-associated genes have put Paneth cells at the center of IBD pathogenesis. In this perspective, we focus on mechanistic studies of different cellular processes in Paneth cells that are regulated by various IBD-associated susceptibility genes, and we discuss the hypothesis that Paneth cells function as the central hub for sensing and regulating intestinal flora in the maintenance of intestinal homeostasis.
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Affiliation(s)
- Zheng Zhang
- Department of Gastroenterology, the Affiliated Yixing Hospital of Jiangsu University, Yixing, 214200, China
| | - Zhihua Liu
- CAS Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
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19
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Zundler S, Caioni M, Müller M, Strauch U, Kunst C, Woelfel G. K+ Channel Inhibition Differentially Regulates Migration of Intestinal Epithelial Cells in Inflamed vs. Non-Inflamed Conditions in a PI3K/Akt-Mediated Manner. PLoS One 2016; 11:e0147736. [PMID: 26824610 PMCID: PMC4732808 DOI: 10.1371/journal.pone.0147736] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 01/07/2016] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Potassium channels have been shown to determine wound healing in different tissues, but their role in intestinal epithelial restitution--the rapid closure of superficial wounds by intestinal epithelial cells (IEC)--remains unclear. METHODS In this study, the regulation of IEC migration by potassium channel modulation was explored with and without additional epidermal growth factor (EGF) under baseline and interferon-γ (IFN-γ)-pretreated conditions in scratch assays and Boyden chamber assays using the intestinal epithelial cell lines IEC-18 and HT-29. To identify possibly involved subcellular pathways, Western Blot (WB)-analysis of ERK and Akt phosphorylation was conducted and PI3K and ERK inhibitors were used in scratch assays. Furthermore, mRNA-levels of the potassium channel KCNN4 were determined in IEC from patients suffering from inflammatory bowel diseases (IBD). RESULTS Inhibition of Ca(2+)-dependent potassium channels significantly increased intestinal epithelial restitution, which could not be further promoted by additional EGF. In contrast, inhibition of KCNN4 after pretreatment with IFN-γ led to decreased or unaffected migration. This effect was abolished by EGF. Changes in Akt, but not in ERK phosphorylation strongly correlated with these findings and PI3K but not ERK inhibition abrogated the effect of KCNN4 inhibition. Levels of KCNN4 mRNA were higher in samples from IBD patients compared with controls. CONCLUSIONS Taken together, we demonstrate that inhibition of KCNN4 differentially regulates IEC migration in IFN-γ-pretreated vs. non pretreated conditions. Moreover, our data propose that the PI3K signaling cascade is responsible for this differential regulation. Therefore, we present a cellular model that contributes new aspects to epithelial barrier dysfunction in chronic intestinal inflammation, resulting in propagation of inflammation and symptoms like ulcers or diarrhea.
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Affiliation(s)
- Sebastian Zundler
- Department of Internal Medicine I, Regensburg University Medical Center, Regensburg, Germany
- Department of Medicine 1, University of Erlangen-Nuremberg, Kussmaul Campus for Medical Research & Translational Research Center, Erlangen, Germany
| | - Massimiliano Caioni
- Department of Internal Medicine I, Regensburg University Medical Center, Regensburg, Germany
| | - Martina Müller
- Department of Internal Medicine I, Regensburg University Medical Center, Regensburg, Germany
| | - Ulrike Strauch
- Department of Internal Medicine I, Regensburg University Medical Center, Regensburg, Germany
| | - Claudia Kunst
- Department of Internal Medicine I, Regensburg University Medical Center, Regensburg, Germany
| | - Gisela Woelfel
- Department of Internal Medicine I, Regensburg University Medical Center, Regensburg, Germany
- * E-mail:
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20
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Henríquez C, Riquelme TT, Vera D, Julio-Kalajzić F, Ehrenfeld P, Melvin JE, Figueroa CD, Sarmiento J, Flores CA. The calcium-activated potassium channel KCa3.1 plays a central role in the chemotactic response of mammalian neutrophils. Acta Physiol (Oxf) 2016; 216:132-45. [PMID: 26138196 DOI: 10.1111/apha.12548] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 02/13/2015] [Accepted: 06/24/2015] [Indexed: 12/27/2022]
Abstract
AIM Neutrophils are the first cells to arrive at sites of injury. Nevertheless, many inflammatory diseases are characterized by an uncontrolled infiltration and action of these cells. Cell migration depends on volume changes that are governed by ion channel activity, but potassium channels in neutrophil have not been clearly identified. We aim to test whether KCa3.1 participates in neutrophil migration and other relevant functions of the cell. METHODS Cytometer and confocal measurements to determine changes in cell volume were used. Cells isolated from human, mouse and horse were tested for KCa3.1-dependent chemotaxis. Chemokinetics, calcium handling and release of reactive oxygen species were measured to determine the role of KCa3.1 in those processes. A mouse model was used to test for neutrophil recruitment after acute lung injury in vivo. RESULTS We show for the first time that KCa3.1 is expressed in mammalian neutrophils. When the channel is inhibited by a pharmacological blocker or by genetic silencing, it profoundly affects cell volume regulation, and chemotactic and chemokinetic properties of the cells. We also demonstrated that pharmacological inhibition of KCa3.1 did not affect calcium entry or reactive oxygen species production in neutrophils. Using a mouse model of acute lung injury, we observed that Kca3.1(-/-) mice are significantly less effective at recruiting neutrophils into the site of inflammation. CONCLUSIONS These results demonstrate that KCa3.1 channels are key actors in the migration capacity of neutrophils, and its inhibition did not affect other relevant cellular functions.
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Affiliation(s)
- C. Henríquez
- Instituto de Farmacología; Facultad de Medicina Veterinaria; Universidad Austral de Chile; Valdivia Chile
| | | | - D. Vera
- Centro de Estudios Científicos (CECs); Valdivia Chile
| | - F. Julio-Kalajzić
- Centro de Estudios Científicos (CECs); Valdivia Chile
- Pontificia Universidad Católica de Valparaíso; Valparaíso Chile
| | - P. Ehrenfeld
- Institutos de Anatomía; Histología y Patología; Universidad Austral de Chile; Valdivia Chile
| | - J. E. Melvin
- Secretory Mechanisms and Dysfunction Section; National Institute of Dental and Craniofacial Research; National Institutes of Health; Bethesda MD USA
| | - C. D. Figueroa
- Institutos de Anatomía; Histología y Patología; Universidad Austral de Chile; Valdivia Chile
| | - J. Sarmiento
- Instituto de Fisiología; Facultad de Medicina; Universidad Austral de Chile; Valdivia Chile
| | - C. A. Flores
- Centro de Estudios Científicos (CECs); Valdivia Chile
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21
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Doecke JD, Simms LA, Zhao ZZ, Roberts RL, Fowler EV, Croft A, Lin A, Huang N, Whiteman DC, Florin THJ, Barclay ML, Merriman TR, Gearry RB, Montgomery GW, Radford-Smith GL. Smoking behaviour modifies IL23r-associated disease risk in patients with Crohn's disease. J Gastroenterol Hepatol 2015; 30:299-307. [PMID: 24989722 DOI: 10.1111/jgh.12674] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/04/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIM The etiology of Crohn's disease (CD) implicates both genetic and environmental factors. Smoking behavior is one environmental risk factor to play a role in the development of CD. The study aimed to assess the contribution of the interleukin 23 receptor (IL23R) in determining disease susceptibility in two independent cohorts of CD, and to investigate the interactions between IL23R variants, smoking behavior, and CD-associated genes, NOD2 and ATG16L1. METHODS Ten IL23R single-nucleotide polymorphisms (SNPs) were genotyped in 675 CD cases, and 1255 controls from Brisbane, Australia (dataset 1). Six of these SNPs were genotyped in 318 CD cases and 533 controls from Canterbury, New Zealand (dataset 2). Case-control analysis of genotype and allele frequencies, and haplotype analysis for all SNPs was conducted. RESULTS We demonstrate a strong increased CD risk for smokers in both datasets (odds ratio 3.77, 95% confidence interval 2.88-4.94), and an additive interaction between IL23R SNPs and cigarette smoking. Ileal involvement was a consistent marker of strong SNP-CD association (P ≤ 0.001), while the lowest minor allele frequencies for location were found in those with colonic CD (L2). Three haplotype blocks were identified across the 10 IL23R SNPs conferring different risk of CD. Haplotypes conferred no further risk of CD when compared with single SNP analyses. CONCLUSION IL23R gene variants determine CD susceptibility in the Australian and New Zealand population, particularly ileal CD. A strong additive interaction exists between IL23R SNPs and smoking behavior resulting in a dramatic increase in disease risk depending upon specific genetic background.
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Affiliation(s)
- James D Doecke
- CSIRO Computational Informatics/Australian E-Health Research Centre, Royal Brisbane and Women's Hospital, Brisbane, Victoria, Australia; Preventative Health Flagship, Melbourne, Victoria, Australia
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22
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Abstract
Technological advances in the large scale analysis of human genetics have generated profound insights into possible genetic contributions to chronic diseases including the inflammatory bowel diseases (IBDs), Crohn's disease and ulcerative colitis. To date, 163 distinct genetic risk loci have been associated with either Crohn's disease or ulcerative colitis, with a substantial degree of genetic overlap between these 2 conditions. Although many risk variants show a reproducible correlation with disease, individual gene associations only affect a subset of patients, and the functional contribution(s) of these risk variants to the onset of IBD is largely undetermined. Although studies in twins have demonstrated that the development of IBD is not mediated solely by genetic risk, it is nevertheless important to elucidate the functional consequences of risk variants for gene function in relevant cell types known to regulate key physiological processes that are compromised in IBD. This article will discuss IBD candidate genes that are known to be, or are suspected of being, involved in regulating the intestinal epithelial barrier and several of the physiological processes presided over by this dynamic and versatile layer of cells. This will include assembly and regulation of tight junctions, cell adhesion and polarity, mucus and glycoprotein regulation, bacterial sensing, membrane transport, epithelial differentiation, and restitution.
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Shanahan MT, Carroll IM, Grossniklaus E, White A, von Furstenberg RJ, Barner R, Fodor AA, Henning SJ, Sartor RB, Gulati AS. Mouse Paneth cell antimicrobial function is independent of Nod2. Gut 2014; 63:903-10. [PMID: 23512834 PMCID: PMC3844066 DOI: 10.1136/gutjnl-2012-304190] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Although polymorphisms of the NOD2 gene predispose to the development of ileal Crohn's disease, the precise mechanisms of this increased susceptibility remain unclear. Previous work has shown that transcript expression of the Paneth cell (PC) antimicrobial peptides (AMPs) α-defensin 4 and α-defensin-related sequence 10 are selectively decreased in Nod2(-/-) mice. However, the specific mouse background used in this previous study is unclear. In light of recent evidence suggesting that mouse strain strongly influences PC antimicrobial activity, we sought to characterise PC AMP function in commercially available Nod2(-/-) mice on a C57BL/6 (B6) background. Specifically, we hypothesised that Nod2(-/-) B6 mice would display reduced AMP expression and activity. DESIGN Wild-type (WT) and Nod2(-/-) B6 ileal AMP expression was assessed via real-time PCR, acid urea polyacrylamide gel electrophoresis and mass spectrometry. PCs were enumerated using flow cytometry. Functionally, α-defensin bactericidal activity was evaluated using a gel-overlay antimicrobial assay. Faecal microbial composition was determined using 454-sequencing of the bacterial 16S gene in cohoused WT and Nod2(-/-) littermates. RESULTS WT and Nod2(-/-) B6 mice displayed similar PC AMP expression patterns, equivalent α-defensin profiles, and identical antimicrobial activity against commensal and pathogenic bacterial strains. Furthermore, minimal differences in gut microbial composition were detected between the two cohoused, littermate mouse groups. CONCLUSIONS Our data reveal that Nod2 does not directly regulate PC antimicrobial activity in B6 mice. Moreover, we demonstrate that previously reported Nod2-dependent influences on gut microbial composition may be overcome by environmental factors, such as cohousing with WT littermates.
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Affiliation(s)
- Michael T Shanahan
- Department of Medicine, Division of Gastroenterology and Hepatology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ian M Carroll
- Department of Medicine, Division of Gastroenterology and Hepatology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Emily Grossniklaus
- Department of Medicine, Division of Gastroenterology and Hepatology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Andrew White
- Department of Medicine, Division of Gastroenterology and Hepatology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Richard J von Furstenberg
- Department of Medicine, Division of Gastroenterology and Hepatology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Roshonda Barner
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Anthony A Fodor
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Susan J Henning
- Department of Medicine, Division of Gastroenterology and Hepatology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - R Balfour Sartor
- Department of Medicine, Division of Gastroenterology and Hepatology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ajay S Gulati
- Department of Pediatrics, Division of Gastroenterology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Ohya S, Fukuyo Y, Kito H, Shibaoka R, Matsui M, Niguma H, Maeda Y, Yamamura H, Fujii M, Kimura K, Imaizumi Y. Upregulation of KCa3.1 K(+) channel in mesenteric lymph node CD4(+) T lymphocytes from a mouse model of dextran sodium sulfate-induced inflammatory bowel disease. Am J Physiol Gastrointest Liver Physiol 2014; 306:G873-85. [PMID: 24674776 DOI: 10.1152/ajpgi.00156.2013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The intermediate-conductance Ca(2+)-activated K(+) channel KCa3.1/KCNN4 plays an important role in the modulation of Ca(2+) signaling through the control of the membrane potential in T lymphocytes. Here, we study the involvement of KCa3.1 in the enlargement of the mesenteric lymph nodes (MLNs) in a mouse model of inflammatory bowel disease (IBD). The mouse model of IBD was prepared by exposing male C57BL/6J mice to 5% dextran sulfate sodium for 7 days. Inflammation-induced changes in KCa3.1 activity and the expressions of KCa3.1 and its regulators in MLN CD4(+) T lymphocytes were monitored by real-time PCR, Western blot, voltage-sensitive dye imaging, patch-clamp, and flow cytometric analyses. Concomitant with an upregulation of KCa3.1a and nucleoside diphosphate kinase B (NDPK-B), a positive KCa3.1 regulator, an increase in KCa3.1 activity was observed in MLN CD4(+) T lymphocytes in the IBD model. Pharmacological blockade of KCa3.1 elicited the following results: 1) a significant decrease in IBD disease severity, as assessed by diarrhea, visible fecal blood, inflammation, and crypt damage of the colon and MLN enlargement compared with control mice, and 2) the restoration of the expression levels of KCa3.1a, NDPK-B, and Th1 cytokines in IBD model MLN CD4(+) T lymphocytes. These findings suggest that the increase in KCa3.1 activity induced by the upregulation of KCa3.1a and NDPK-B may be involved in the pathogenesis of IBD by mediating the enhancement of the proliferative response in MLN CD4(+) T lymphocyte and, therefore, that the pharmacological blockade of KCa3.1 may decrease the risk of IBD.
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Affiliation(s)
- Susumu Ohya
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto, Japan; Department of Molecular & Cellular Pharmacology, Nagoya City University, Nagoya, Japan;
| | - Yuka Fukuyo
- Department of Molecular & Cellular Pharmacology, Nagoya City University, Nagoya, Japan
| | - Hiroaki Kito
- Department of Molecular & Cellular Pharmacology, Nagoya City University, Nagoya, Japan
| | - Rina Shibaoka
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Miki Matsui
- Department of Molecular & Cellular Pharmacology, Nagoya City University, Nagoya, Japan
| | - Hiroki Niguma
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Yasuhiro Maeda
- Department of Hospital Pharmacy, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan; and
| | - Hisao Yamamura
- Department of Molecular & Cellular Pharmacology, Nagoya City University, Nagoya, Japan
| | - Masanori Fujii
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Kazunori Kimura
- Department of Hospital Pharmacy, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan; and Department of Clinical Pharmacy, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Yuji Imaizumi
- Department of Molecular & Cellular Pharmacology, Nagoya City University, Nagoya, Japan
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Bertuccio CA, Lee SL, Wu G, Butterworth MB, Hamilton KL, Devor DC. Anterograde trafficking of KCa3.1 in polarized epithelia is Rab1- and Rab8-dependent and recycling endosome-independent. PLoS One 2014; 9:e92013. [PMID: 24632741 PMCID: PMC3954861 DOI: 10.1371/journal.pone.0092013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 02/16/2014] [Indexed: 02/01/2023] Open
Abstract
The intermediate conductance, Ca2+-activated K+ channel (KCa3.1) targets to the basolateral (BL) membrane in polarized epithelia where it plays a key role in transepithelial ion transport. However, there are no studies defining the anterograde and retrograde trafficking of KCa3.1 in polarized epithelia. Herein, we utilize Biotin Ligase Acceptor Peptide (BLAP)-tagged KCa3.1 to address these trafficking steps in polarized epithelia, using MDCK, Caco-2 and FRT cells. We demonstrate that KCa3.1 is exclusively targeted to the BL membrane in these cells when grown on filter supports. Following endocytosis, KCa3.1 degradation is prevented by inhibition of lysosomal/proteosomal pathways. Further, the ubiquitylation of KCa3.1 is increased following endocytosis from the BL membrane and PR-619, a deubiquitylase inhibitor, prevents degradation, indicating KCa3.1 is targeted for degradation by ubiquitylation. We demonstrate that KCa3.1 is targeted to the BL membrane in polarized LLC-PK1 cells which lack the μ1B subunit of the AP-1 complex, indicating BL targeting of KCa3.1 is independent of μ1B. As Rabs 1, 2, 6 and 8 play roles in ER/Golgi exit and trafficking of proteins to the BL membrane, we evaluated the role of these Rabs in the trafficking of KCa3.1. In the presence of dominant negative Rab1 or Rab8, KCa3.1 cell surface expression was significantly reduced, whereas Rabs 2 and 6 had no effect. We also co-immunoprecipitated KCa3.1 with both Rab1 and Rab8. These results suggest these Rabs are necessary for the anterograde trafficking of KCa3.1. Finally, we determined whether KCa3.1 traffics directly to the BL membrane or through recycling endosomes in MDCK cells. For these studies, we used either recycling endosome ablation or dominant negative RME-1 constructs and determined that KCa3.1 is trafficked directly to the BL membrane rather than via recycling endosomes. These results are the first to describe the anterograde and retrograde trafficking of KCa3.1 in polarized epithelia cells.
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Affiliation(s)
- Claudia A. Bertuccio
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Shih-Liang Lee
- Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, Otago, New Zealand
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States of America
| | - Michael B. Butterworth
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Kirk L. Hamilton
- Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, Otago, New Zealand
- * E-mail: (DCD); (KLH)
| | - Daniel C. Devor
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail: (DCD); (KLH)
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26
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Abstract
Paneth cells are long-lived secretory cells that reside in the base of the crypts of Lieberkühn of the small intestine. They produce an arsenal of molecules that are involved in numerous biological processes, ranging from the control of gut microbial populations to supporting the intestinal stem cell niche. Because of these important functions, Paneth cell abnormalities are becoming implicated in a variety of disease processes. As such, it is necessary to establish parameters that will allow for the comprehensive study of Paneth cells in health and disease. In this addendum, we highlight critical design aspects involved in the study of Paneth cells and their downstream effects on the intestinal microbiota. The importance of this approach is demonstrated by our recent findings that Nod2 does not regulate mouse Paneth cell antimicrobial function, in contrast to previous reports. This work defines key issues to consider when studying Paneth cells in mouse systems.
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Affiliation(s)
- Michael T Shanahan
- Department of Medicine; Division of Gastroenterology and Hepatology; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Ian M Carroll
- Department of Medicine; Division of Gastroenterology and Hepatology; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Ajay S Gulati
- Department of Pediatrics; Division of Gastroenterology; University of North Carolina at Chapel Hill; Chapel Hill, NC USA,Correspondence to: Ajay S Gulati,
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27
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Abstract
The intestinal mucosa interfaces with a complex, dense community of microorganisms, including hundreds of species of resident microbiota and many transient microbes entering from food- and water-borne sources. In the small intestine, Paneth cells (specialized secretory epithelial cells) produce abundant quantities of α-defensins and several other antibiotic peptides. Human Paneth cells make two α-defensins: HD5 and HD6. Data from in vivo models indicate that Paneth cell α-defensins play a pivotal role in defense from food- and water-borne pathogens in the intestine. The mechanism by which these two α-defensins protect from enteric pathogens is quite distinct. HD5 is a potent antimicrobial that kills target microbes by membrane disruption, whereas HD6 is newly discovered to self-assemble to form fibrils and nanonets that surround and entangle bacteria. Recent data suggest that HD5 also serves to help shape the composition of the colonizing microbiota. Studies in humans suggest that reduced expression of HD5 and HD6 is a fundamental feature of ileal Crohn's disease. Mechanistically, the link between reduced Paneth cell α-defensin expression and ileal Crohn's disease pathogenesis may be a result of the weakened mucosal antimicrobial defense and/or alterations in the composition of commensal microbiota.
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Affiliation(s)
- Charles L Bevins
- Department of Microbiology and Immunology, School of Medicine, University of California Davis, Davis, Calif., USA
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28
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Abstract
The pathogenesis of inflammatory bowel disease (IBD) is very complex, including a variety of genetic and environmental contributing factors. In this context, over the past few years, a picture of IBD as a primary defect of the innate immune system rather than the adaptive immune system has evolved. The intestinal antimicrobial barrier morphologically consists of a single layer of epithelial cells and the mucus and constitutes the first defense mechanism against the microbial burden of the gut. From a more mechanistic point of view, this barrier additionally depends on a crucial interplay between the mucus and antimicrobial peptides like for instance defensins. Disturbances in this system are in the pathophysiological center stage of IBD genesis and progression. In this article we will give a short overview about some of the key mechanisms in this context with special attention on defensins and the mucus layer.
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Affiliation(s)
- Thomas Klag
- Department of Internal Medicine I, Robert Bosch Hospital, Stuttgart, Germany
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29
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Ostaff MJ, Stange EF, Wehkamp J. Antimicrobial peptides and gut microbiota in homeostasis and pathology. EMBO Mol Med 2013; 5:1465-83. [PMID: 24039130 PMCID: PMC3799574 DOI: 10.1002/emmm.201201773] [Citation(s) in RCA: 222] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 06/19/2013] [Accepted: 07/04/2013] [Indexed: 12/17/2022] Open
Abstract
We survive because we adapted to a world of microorganisms. All our epithelial surfaces participate in keeping up an effective barrier against microbes while not initiating ongoing inflammatory processes and risking collateral damage to the host. Major players in this scenario are antimicrobial peptides (AMPs). Such broad-spectrum innate antibiotics are in part produced by specialized cells but also widely sourced from all epithelia as well as circulating inflammatory cells. AMPs belong to an ancient defense system found in all organisms and participated in a preservative co-evolution with a complex microbiome. Particularly interesting interactions between host barrier and microbiota can be found in the gut. The intestinal cell lining not only has to maintain a tightly regulated homeostasis during its high-throughput regeneration, but also a balanced relationship towards an extreme number of mutualistic or commensal inhabitants. Recent research suggests that advancing our understanding of the circumstances of such balanced and sometimes imbalanced interactions between gut microbiota and host AMPs should have therapeutic implications for different intestinal disorders.
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Affiliation(s)
- Maureen J Ostaff
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany and University of Tuebingen, Germany
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30
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Abstract
Paneth cells are highly specialized epithelial cells of the small intestine, where they coordinate many physiological functions. First identified more than a century ago on the basis of their readily discernible secretory granules by routine histology, these cells are located at the base of the crypts of Lieberkühn, tiny invaginations that line the mucosal surface all along the small intestine. Investigations over the past several decades determined that these cells synthesize and secrete substantial quantities of antimicrobial peptides and proteins. More recent studies have determined that these antimicrobial molecules are key mediators of host-microbe interactions, including homeostatic balance with colonizing microbiota and innate immune protection from enteric pathogens. Perhaps more intriguing, Paneth cells secrete factors that help sustain and modulate the epithelial stem and progenitor cells that cohabitate in the crypts and rejuvenate the small intestinal epithelium. Dysfunction of Paneth cell biology contributes to the pathogenesis of chronic inflammatory bowel disease.
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Affiliation(s)
- Hans C Clevers
- Hubrecht Institute-KNAW, University Medical Center Utrecht, Uppsalalaan, Utrecht 3584CT, The Netherlands.
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31
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Wulff H, Köhler R. Endothelial small-conductance and intermediate-conductance KCa channels: an update on their pharmacology and usefulness as cardiovascular targets. J Cardiovasc Pharmacol 2013; 61:102-12. [PMID: 23107876 DOI: 10.1097/FJC.0b013e318279ba20] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Most cardiovascular researchers are familiar with intermediate-conductance KCa3.1 and small-conductance KCa2.3 channels because of their contribution to endothelium-derived hyperpolarization. However, to immunologists and neuroscientists, these channels are primarily known for their role in lymphocyte activation and neuronal excitability. KCa3.1 is involved in the proliferation and migration of T cells, B cells, mast cells, macrophages, fibroblasts, and dedifferentiated vascular smooth muscle cells and is, therefore, being pursued as a potential target for use in asthma, immunosuppression, and fibroproliferative disorders. In contrast, the 3 KCa2 channels (KCa2.1, KCa2.2, and KCa2.3) contribute to the neuronal medium afterhyperpolarization and, depending on the type of neuron, are involved in determining firing rates and frequencies or in regulating bursting. KCa2 activators are accordingly being studied as potential therapeutics for ataxia and epilepsy, whereas KCa2 channel inhibitors like apamin have long been known to improve learning and memory in rodents. Given this background, we review the recent discoveries of novel KCa3.1 and KCa2.3 modulators and critically assess the potential of KCa activators for the treatment of diabetes and cardiovascular diseases by improving endothelium-derived hyperpolarizations.
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Wang J, Xiang M. Targeting potassium channels Kv1.3 and KC a 3.1: routes to selective immunomodulators in autoimmune disorder treatment? Pharmacotherapy 2013; 33:515-28. [PMID: 23649812 DOI: 10.1002/phar.1236] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The Kv1.3 and KC a 3.1 potassium channels are promising targets for the treatment of autoimmune disorders. Many Kv1.3 and KC a 3.1 blockers have a more favorable adverse event profiles than existing immunosuppressants, suggesting the selectivity of Kv1.3 and KC a 3.1 blockade. The Kv1.3 and KC a 3.1 blockers exert differential effects in different autoimmune diseases. The Kv1.3 inhibitors or gene deletion have been shown to have benefits in multiple sclerosis, type 1 diabetes, rheumatoid arthritis, psoriasis, and rapidly progressive glomerulonephritis. The KC a 3.1 blockers have demonstrated efficacy in human primary biliary cirrhosis and showed protective effects in animal models of severe colitis, allergic encephalomyelitis, inflammatory bowel disease, and multiple sclerosis. The KC a 3.1 blockers are not considered candidates for treatment of multiple sclerosis. The selective immunosuppressive effects of the Kv1.3 and KC a 3.1 blockers are due to the differences in their distribution on autoimmune-related immune cells and tissues and β1 integrin (very late activating antigen)-Kv1.3 channel cross-talk.
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Affiliation(s)
- Jun Wang
- Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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33
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Doecke JD, Simms LA, Zhao ZZ, Huang N, Hanigan K, Krishnaprasad K, Roberts RL, Andrews JM, Mahy G, Bampton P, Lewindon P, Florin T, Lawrance IC, Gearry RB, Montgomery GW, Radford-Smith GL. Genetic susceptibility in IBD: overlap between ulcerative colitis and Crohn's disease. Inflamm Bowel Dis 2013; 19:240-5. [PMID: 23348120 DOI: 10.1097/MIB.0b013e3182810041] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND The etiology of ulcerative colitis (UC) and Crohn's disease (CD) involves both genetic and environmental components. Multiple UC and CD susceptibility genes have been identified through genome-wide association studies and subsequent meta-analyses. These studies have also highlighted the presence of genes common to both diseases, and shared with several other autoimmune disorders. The aim of this study was to identify single nucleotide polymorphisms (SNPs) recently identified by the International IBD Genetics Consortium (IIBDGC) demonstrating that highly significant associations with CD could also confer genetic susceptibility to UC. METHODS Statistical modeling was performed on 29 CD-associated SNPs. The study comprised of 1652 UC cases from the Australia and New Zealand IBD Consortium and 2363 Australian population-based controls. RESULTS After adjustment for multiple comparisons, only one SNP, rs3024505, was significantly associated with UC (P = 0.001). Independent chi-square analyses identified odds ratios of 2.22 (1.48-3.37) for the rare homozygous genotype, and 1.20 (1.06-1.35) for the minor allele. Five other SNPs demonstrated moderate to weak associations with UC. CONCLUSIONS Of the 29 SNPs conferring high genetic susceptibility to CD, 28 were not associated with UC, thus indicating that for this SNP set there is a low level of overlap between the two major forms of IBD. Only one SNP, rs3024505 (Chr 1q32.1, upstream of IL10), was associated with susceptibility to UC. The identification of this SNP replicates a finding from Franke et al (2008), where the rs3024505 SNP was strongly associated with UC across multiple European populations.
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Jäger S, Stange EF, Wehkamp J. Inflammatory bowel disease: an impaired barrier disease. Langenbecks Arch Surg. 2013;398:1-12. [PMID: 23160753 DOI: 10.1007/s00423-012-1030-9] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 11/01/2012] [Indexed: 12/19/2022]
Abstract
BACKGROUND The intestinal barrier is a delicate structure composed of a single layer of epithelial cells, the mucus, commensal bacteria, immune cells, and antibodies. Furthermore, a wealth of antimicrobial peptides (AMPs) can be found in the mucus and defend the mucosa. Different lines of investigations now point to a prominent pathophysiological role of defensins, an important family of AMPs, in the pathogenesis of inflammatory bowel disease and, particularly, in small intestinal Crohn's disease. PURPOSE In this review, we introduce the different antimicrobial peptides of the intestinal mucosa and describe their function, their expression pattern along the gastrointestinal tract, and their spatial relationship to the mucus layer. We then focus on the alterations found in inflammatory bowel disease. Small intestinal Crohn's disease (CD) is closely linked to defects in Paneth cells (specialized secretory epithelial cells at the bottom crypts) which secrete α-defensin human defensin (HD)-5 in huge quantities in healthy individuals. Decreased expression of these antimicrobial peptides is found in ileal CD, and single nucleotide polymorphisms with the highest linkage to CD affect genes involved in Paneth cell biology and defensin secretion. Additionally, antimicrobial peptides have a role in ulcerative colitis, where the depleted mucus layer cannot fulfill its crucial function of binding defensins and other AMPs to their proper site of action. CONCLUSION Inflammatory bowel disease arises when the mucosal barrier is compromised in its defense against challenges from the intestinal microbiota. In ileal CD, a strong association can be found between diminished expression or defective function of defensins and the advent of intestinal inflammation.
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35
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Abstract
The intestine is the most densely colonized site in both mice and man. Recent data suggest that the intestinal flora is, in part, controlled by antimicrobial substances secreted by the intestinal epithelium. The defense system of the small intestine includes a protective mucus layer, a high turnover of epithelial cells, and a regulated secretion of effector molecules, notably antimicrobial peptides. Human and mouse small intestines share many similarities in their intestinal defense micro-organization, including the secretion of the well-known α-defensins. Mice, however, produce an additional unique antimicrobial peptide family, the CRS (cryptdin-related sequences)-peptides, not found in man. This review comprises a detailed presentation of the peptide-based defense of the gut, with specific emphasis on the CRS-peptide family. The first part presents the current knowledge of the CRS-peptide family's biochemical characteristics and nomenclature, and the second part is devoted to the possible role of this family in the homeostasis of the gut.
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Affiliation(s)
- M L Andersson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
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36
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Abstract
Strong evidence indicates that inflammatory bowel disease, including Crohn disease and ulcerative colitis, is a result of an inappropriate inflammatory response in which genetic and environmental factors play important roles. This review discusses several single-nucleotide polymorphisms with either susceptibility or protective effects on inflammatory bowel disease.
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Affiliation(s)
- Manuela G Neuman
- Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, and In Vitro Drug Safety and Biotechnology, MaRS, Toronto, Ontario, Canada.
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37
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Koslowski MJ, Teltschik Z, Beisner J, Schaeffeler E, Wang G, Kübler I, Gersemann M, Cooney R, Jewell D, Reinisch W, Vermeire S, Rutgeerts P, Schwab M, Stange EF, Wehkamp J. Association of a functional variant in the Wnt co-receptor LRP6 with early onset ileal Crohn's disease. PLoS Genet 2012; 8:e1002523. [PMID: 22393312 PMCID: PMC3285585 DOI: 10.1371/journal.pgen.1002523] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 12/20/2011] [Indexed: 02/07/2023] Open
Abstract
Ileal Crohn's Disease (CD), a chronic small intestinal inflammatory disorder, is characterized by reduced levels of the antimicrobial peptides DEFA5 (HD-5) and DEFA6 (HD-6). Both of these α-defensins are exclusively produced in Paneth cells (PCs) at small intestinal crypt bases. Different ileal CD-associated genes including NOD2, ATG16L1, and recently the β-catenin-dependant Wnt transcription factor TCF7L2 have been linked to impaired PC antimicrobial function. The Wnt pathway influences gut mucosal homeostasis and PC maturation, besides directly controlling HD-5/6 gene expression. The herein reported candidate gene study focuses on another crucial Wnt factor, the co-receptor low density lipoprotein receptor-related protein 6 (LRP6). We analysed exonic single nucleotide polymorphisms (SNPs) in a large cohort (Oxford: n = 1,893) and prospectively tested 2 additional European sample sets (Leuven: n = 688, Vienna: n = 1,628). We revealed an association of a non-synonymous SNP (rs2302685; Ile1062Val) with early onset ileal CD (OR 1.8; p = 0.00034; for homozygous carriers: OR 4.1; p = 0.00004) and additionally with penetrating ileal CD behaviour (OR 1.3; p = 0.00917). In contrast, it was not linked to adult onset ileal CD, colonic CD, or ulcerative colitis. Since the rare variant is known to impair LRP6 activity, we investigated its role in patient mucosa. Overall, LRP6 mRNA was diminished in patients independently from the genotype. Analysing the mRNA levels of PC product in biopsies from genotyped individuals (15 controls, 32 ileal, and 12 exclusively colonic CD), we found particularly low defensin levels in ileal CD patients who were carrying the variant. In addition, we confirmed a direct relationship between LRP6 activity and the transcriptional expression of HD-5 using transient transfection. Taken together, we identified LRP6 as a new candidate gene in ileal CD. Impairments in Wnt signalling and Paneth cell biology seem to represent pathophysiological hallmarks in small intestinal inflammation and should therefore be considered as interesting targets for new therapeutic approaches.
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Affiliation(s)
- Maureen J. Koslowski
- Dr. Margarete-Fischer-Bosch Institute for Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
| | - Zora Teltschik
- Dr. Margarete-Fischer-Bosch Institute for Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
| | - Julia Beisner
- Dr. Margarete-Fischer-Bosch Institute for Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
| | - Elke Schaeffeler
- Dr. Margarete-Fischer-Bosch Institute for Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
| | - Guoxing Wang
- Dr. Margarete-Fischer-Bosch Institute for Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
| | | | - Michael Gersemann
- Dr. Margarete-Fischer-Bosch Institute for Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
- Robert-Bosch-Hospital Stuttgart, Stuttgart, Germany
| | - Rachel Cooney
- Medical Science Division, John Radcliffe Hospital, Oxford, United Kingdom
| | - Derek Jewell
- Medical Science Division, John Radcliffe Hospital, Oxford, United Kingdom
| | - Walter Reinisch
- Department of Internal Medicine III, Division of Gastroenterology and Hepatology, Medical University Vienna, Vienna, Austria
| | - Séverine Vermeire
- Division of Gastroenterology, University Hospital Gasthuisberg, Leuven, Belgium
| | - Paul Rutgeerts
- Division of Gastroenterology, University Hospital Gasthuisberg, Leuven, Belgium
| | - Matthias Schwab
- Dr. Margarete-Fischer-Bosch Institute for Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
- Department of Clinical Pharmacology, Institute of Experimental and Clinical Pharmacology and Toxicology, University Hospital, Tübingen, Germany
| | | | - Jan Wehkamp
- Dr. Margarete-Fischer-Bosch Institute for Clinical Pharmacology and University of Tübingen, Stuttgart, Germany
- Robert-Bosch-Hospital Stuttgart, Stuttgart, Germany
- * E-mail:
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38
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Abstract
In clarifying the pathogenesis of inflammatory bowel diseases, a dysregulation of the adaptive immune function was the main focus of research in the last decade. With increasing knowledge of antimicrobial peptides, a primary disturbed barrier function and the system of innate immunity has recently received increasing attention. Contrary to the common understanding of irritable bowel syndrome as a functional disorder, there is first evidence for an involvement of innate immunity for this condition. Peptides with high relevance seem to be the class of human defensins. This article will thus discuss current advances in immunologic research of inflammatory bowel disease and irritable bowel syndrome, focusing on defensins and their possible role as biomarkers of these diseases.
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Affiliation(s)
- Jost Langhorst
- Integrative Gastroenterology, Department of Integrative and Internal Medicine, Kliniken Essen-Mitte, University of Duisburg-Essen, Knappschafts Krankenhaus, Am Deimelsberg 34a, 45276 Essen, Germany.
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39
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Nakamura K, Ayabe T. Paneth cells and stem cells in the intestinal stem cell niche and their association with inflammatory bowel disease. Inflamm Regen 2012. [DOI: 10.2492/inflammregen.32.053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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40
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Abstract
The voltage-gated Kv1.3 and the calcium-activated KCa3.1 potassium channel modulate many calcium-dependent cellular processes in immune cells, including T-cell activation and proliferation, and have therefore been proposed as novel therapeutic targets for immunomodulation. Kv1.3 is highly expressed in CCR7(-) effector memory T cells and is emerging as a target for T-cell mediated diseases like multiple sclerosis, rheumatoid arthritis, type-1 diabetes mellitus, allergic contact dermatitis, and psoriasis. KCa3.1 in contrast is expressed in CCR7(+) naïve and central memory T cells, as well as in mast cells, macrophages, dedifferentiated vascular smooth muscle cells, fibroblasts, vascular endothelium, and airway epithelium. Given this expression pattern, KCa3.1 is a potential therapeutic target for conditions ranging from inflammatory bowel disease, multiple sclerosis, arthritis, and asthma to cardiovascular diseases like atherosclerosis and post-angioplasty restenosis. Results from animal studies have been supportive of the therapeutic potential of both Kv1.3 and KCa3.1 blockers and have also not shown any toxicities associated with pharmacological Kv1.3 and KCa3.1 blockade. To date, two compounds targeting Kv1.3 are in preclinical development but, so far, no Kv1.3 blocker has advanced into clinical trials. KCa3.1 blockers, on the other hand, have been evaluated in clinical trials for sickle cell anemia and exercise-induced asthma, but have so far not shown efficacy. However, the trial results support KCa3.1 as a safe therapeutic target, and will hopefully help enable clinical trials for other medical conditions that might benefit from KCa3.1 blockade.
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Affiliation(s)
- Jenny Lam
- Department of Pharmacology, University of California Davis, Davis, CA 95616, USA
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41
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Liebau S, Tischendorf M, Ansorge D, Linta L, Stockmann M, Weidgang C, Iacovino M, Boeckers T, von Wichert G, Kyba M, Kleger A. An inducible expression system of the calcium-activated potassium channel 4 to study the differential impact on embryonic stem cells. Stem Cells Int 2011; 2011:456815. [PMID: 21941566 PMCID: PMC3173888 DOI: 10.4061/2011/456815] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 06/14/2011] [Indexed: 11/20/2022] Open
Abstract
Rationale. The family of calcium-activated potassium channels consists of four members with varying biological functions and conductances. Besides membrane potential modulation, SK channels have been found to be involved in cardiac pacemaker cell development from ES cells and morphological shaping of neural stem cells. Objective. Distinct SK channel subtype expression in ES cells might elucidate their precise impact during cardiac development. We chose SK channel subtype 4 as a potential candidate influencing embryonic stem cell differentiation. Methods. We generated a doxycycline inducible mouse ES cell line via targeted homologous recombination of a cassette expressing a bicistronic construct encoding SK4 and a fluorophore from the murine HPRT locus. Conclusion. We characterized the mouse ES cell line iSK4-AcGFP. The cassette is readily expressed under the control of doxycycline, and the overexpression of SK4 led to an increase in cardiac and pacemaker cell differentiation thereby serving as a unique tool to characterize the cell biological variances due to specific SK channel overexpression.
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Affiliation(s)
- Stefan Liebau
- Institute for Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany
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42
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Abstract
Building and maintaining a homeostatic relationship between a host and its colonizing microbiota entails ongoing complex interactions between the host and the microorganisms. The mucosal immune system, including epithelial cells, plays an essential part in negotiating this equilibrium. Paneth cells (specialized cells in the epithelium of the small intestine) are an important source of antimicrobial peptides in the intestine. These cells have become the focus of investigations that explore the mechanisms of host-microorganism homeostasis in the small intestine and its collapse in the processes of infection and chronic inflammation. In this Review, we provide an overview of the intestinal microbiota and describe the cell biology of Paneth cells, emphasizing the composition of their secretions and the roles of these cells in intestinal host defence and homeostasis. We also highlight the implications of Paneth cell dysfunction in susceptibility to chronic inflammatory bowel disease.
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43
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Abstract
Building and maintaining a homeostatic relationship between a host and its colonizing microbiota entails ongoing complex interactions between the host and the microorganisms. The mucosal immune system, including epithelial cells, plays an essential part in negotiating this equilibrium. Paneth cells (specialized cells in the epithelium of the small intestine) are an important source of antimicrobial peptides in the intestine. These cells have become the focus of investigations that explore the mechanisms of host-microorganism homeostasis in the small intestine and its collapse in the processes of infection and chronic inflammation. In this Review, we provide an overview of the intestinal microbiota and describe the cell biology of Paneth cells, emphasizing the composition of their secretions and the roles of these cells in intestinal host defence and homeostasis. We also highlight the implications of Paneth cell dysfunction in susceptibility to chronic inflammatory bowel disease.
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44
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Abstract
Acute and chronic inflammations of mucosal surfaces are complex events in which the effector mechanisms of innate and adaptive immune systems interact with pathogenic and commensal bacteria. The role of constitutive and inducible antimicrobial peptides in intestinal inflammation has been investigated thoroughly over the recent years, and their involvement in various disease states is expanded ever more. Especially in the intestines, a critical balance between luminal bacteria and the antimicrobial peptides is essential, and a breakdown in barrier function by impaired production of defensins is already implicated in Crohn's disease. In this paper, we focus on the role of antimicrobial peptides in inflammatory processes along the gastrointestinal tract, while considering the resident and pathogenic flora encountered at the specific sites. The role of antimicrobial peptides in the primary events of inflammatory bowel diseases receives special attention.
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Affiliation(s)
- Simon Jäger
- Department of Internal Medicine I, Robert Bosch Hospital, Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Auerbachstr. 112, 70376 Stuttgart, Germany
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45
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Abstract
In about 70% of patients Crohn's disease (CD) affects the small intestine. This disease location is stable over time and associated with a genetic background different from isolated colonic disease. A characteristic feature of small intestinal host defense is the presence of Paneth cells at the bottom of the crypts of Lieberkühn. These cells produce different broad spectrum antimicrobial peptides (AMPs) most abundantly the α-defensins HD-5 and -6 (DEFA5 und DEFA6). In small intestinal Crohn's disease both these PC products are specifically reduced. As a functional consequence, ileal extracts from Crohn's disease patients are compromised in clearing bacteria and enteroadherent E. coli colonize the mucosa. Mechanisms for defective antimicrobial Paneth cell function are complex and include an association with a NOD2 loss of function mutation, a disturbance of the Wnt pathway transcription factor TCF7L2 (also known as TCF4), the autophagy factor ATG16L1, the endosomal stress protein XBP1, the toll-like receptor TLR9, the calcium mediated potassium channel KCNN4 as well as mutations or inactivation of HD5. Thus we conclude that small intestinal Crohn's disease is most likely a complex disease of the Paneth cell: Paneth's disease.
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Affiliation(s)
- Jan Wehkamp
- Robert-Bosch-Krankenhaus Stuttgart, Auerbachstr 110, 7076 Stuttgart, Germany.
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