1
|
Mavrogeni ME, Asadpoor M, Henricks PAJ, Keshavarzian A, Folkerts G, Braber S. Direct Action of Non-Digestible Oligosaccharides against a Leaky Gut. Nutrients 2022; 14:4699. [PMID: 36364961 PMCID: PMC9655944 DOI: 10.3390/nu14214699] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 10/28/2023] Open
Abstract
The epithelial monolayer is the primary determinant of mucosal barrier function, and tight junction (TJ) complexes seal the paracellular space between the adjacent epithelial cells and represent the main "gate-keepers" of the paracellular route. Impaired TJ functionality results in increased permeation of the "pro-inflammatory" luminal contents to the circulation that induces local and systemic inflammatory and immune responses, ultimately triggering and/or perpetuating (chronic) systemic inflammatory disorders. Increased gut leakiness is associated with intestinal and systemic disease states such as inflammatory bowel disease and neurodegenerative diseases such as Parkinson's disease. Modulation of TJ dynamics is an appealing strategy aiming at inflammatory conditions associated with compromised intestinal epithelial function. Recently there has been a growing interest in nutraceuticals, particularly in non-digestible oligosaccharides (NDOs). NDOs confer innumerable health benefits via microbiome-shaping and gut microbiota-related immune responses, including enhancement of epithelial barrier integrity. Emerging evidence supports that NDOs also exert health-beneficial effects on microbiota independently via direct interactions with intestinal epithelial and immune cells. Among these valuable features, NDOs promote barrier function by directly regulating TJs via AMPK-, PKC-, MAPK-, and TLR-associated pathways. This review provides a comprehensive overview of the epithelial barrier-protective effects of different NDOs with a special focus on their microbiota-independent modulation of TJs.
Collapse
Affiliation(s)
- Maria Eleni Mavrogeni
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands
| | - Mostafa Asadpoor
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands
| | - Paul A. J. Henricks
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands
| | - Ali Keshavarzian
- Division of Gastroenterology, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA
| | - Gert Folkerts
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands
| | - Saskia Braber
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CG Utrecht, The Netherlands
| |
Collapse
|
2
|
Souza JB, Tsantarlis K, Tonelli RR. Oxygen-dependent regulation of permeability in low resistance intestinal epithelial cells infected with Giardia lamblia. Exp Parasitol 2022; 240:108329. [PMID: 35868574 DOI: 10.1016/j.exppara.2022.108329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 06/22/2022] [Accepted: 07/11/2022] [Indexed: 11/26/2022]
Abstract
Intestinal epithelial cells (IECs) reside in a highly anaerobic environment that is subject to daily fluctuations in partial oxygen pressure (pO2), depending on intestinal tissue perfusion. This condition, known as physiological hypoxia, has a major impact on the maintenance of gut homeostasis, such as effects on the integrity and function of the intestinal epithelial barrier. Giardia lamblia is a microaerophilic protozoan parasite that infects and colonizes the small intestine of its host, causing watery diarrhea. The disease, known as giardiasis, is associated with enhanced intestinal permeability and disruption or reorganization of tight junction (TJ) proteins between IECs. Given the central role of oxygen in gut homeostasis, in this study, we aimed to evaluate whether pO2 affects intestinal permeability (flux of ions and macromolecules) and TJ protein expression in human IECs during G. lamblia infection. Using human cell lines HuTu-80 and Caco-2 as models of "loose" (low resistance) and "tight" (high resistance) intestines, respectively, we elucidated that low pO2 drives intestinal barrier dysfunction in IECs infected with trophozoites through dephosphorylation of protein kinase C (PKC α/β II). Additionally, we demonstrated that IECs infected with trophozoites in the presence of a pharmacological PKC activator (phorbol 12-myristate 13-acetate) partially restored the barrier function, which was correlated with increased protein expression levels of zonula occludens (ZO)-2 and occludin. Collectively, these results support the emerging theory that molecular oxygen impacts gut homeostasis during Giardia infection via direct host signaling pathways. These findings further our knowledge regarding Giardia-host interactions and the pathophysiological mechanisms of human giardiasis.
Collapse
Affiliation(s)
- Juliana Bizarri Souza
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, 04023-062, São Paulo, SP, Brazil
| | - Katherine Tsantarlis
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, 04023-062, São Paulo, SP, Brazil
| | - Renata Rosito Tonelli
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, 04023-062, São Paulo, SP, Brazil; Departamento de Ciências Farmacêuticas, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, 09913-030, Diadema, SP, Brazil.
| |
Collapse
|
3
|
Baggio CH, Shang J, Gordon MH, Stephens M, von der Weid PY, Nascimento AM, Román Y, Cipriani TR, MacNaughton WK. The dietary fibre rhamnogalacturonan improves intestinal epithelial barrier function in a microbiota-independent manner. Br J Pharmacol 2021; 179:337-352. [PMID: 34784647 DOI: 10.1111/bph.15739] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 09/23/2021] [Accepted: 10/01/2021] [Indexed: 10/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Dietary fibre comprises a complex group of polysaccharides that are indigestible but are fermented by gut microbiota, promoting beneficial effects to the intestinal mucosa indirectly through the production of short chain fatty acids. We found that a polysaccharide, rhamnogalacturonan (RGal), from the plant Acmella oleracea, has direct effects on intestinal epithelial barrier function. Our objective was to determine the mechanism whereby RGal enhances epithelial barrier function. EXPERIMENTAL APPROACH Monolayers of colonic epithelial cell lines (Caco-2, T84) and of human primary cells from organoids were mounted in Ussing chambers to assess barrier function. The cellular mechanism of RGal effects on barrier function was determined using inhibitors of TLR-4 and PKC isoforms. KEY RESULTS Apically applied RGal (1000 μg/ml) significantly enhanced barrier function as shown by increased transepithelial electrical resistance (TER) and reduced fluorescein isothiocyanate (FITC)-dextran flux in Caco-2, T84 and human primary cell monolayers, and accelerated tight junction reassembly in Caco-2 cells in a calcium switch assay. RGal also reversed the barrier-damaging effects of inflammatory cytokines on FITC-dextran flux and preserved the tight junction distribution of occludin. RGal activated TLR4 in TLR4-expressing HEK reporter cells, an effect that was significantly inhibited by the TLR4 inhibitor, C34. The effect of RGal was also dependent on PKC, specifically the isoforms PKCd and PKCζ. CONCLUSION AND IMPLICATIONS RGal enhances intestinal epithelial barrier function through activation of TLR4 and PKC signaling pathways. Elucidation of RGal mechanisms of action could lead to new, dietary approaches to enhance mucosal healing in inflammatory bowel diseases.
Collapse
Affiliation(s)
- Cristiane H Baggio
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Judie Shang
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Marilyn H Gordon
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Matthew Stephens
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | | | - Adamara M Nascimento
- Department of Biochemistry, Universidade Federal do Acre, Rio Branco, AC, Brazil.,Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Yony Román
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Thales R Cipriani
- Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Wallace K MacNaughton
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
4
|
Yu H, Wang Y, Zeng X, Cai S, Wang G, Liu L, Huang S, Li N, Liu H, Ding X, Song Q, Qiao S. Therapeutic administration of the recombinant antimicrobial peptide microcin J25 effectively enhances host defenses against gut inflammation and epithelial barrier injury induced by enterotoxigenic
Escherichia coli
infection. FASEB J 2019; 34:1018-1037. [DOI: 10.1096/fj.201901717r] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 10/29/2019] [Accepted: 10/30/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Haitao Yu
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| | - Yuming Wang
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| | - Xiangfang Zeng
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| | - Shuang Cai
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| | - Gang Wang
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| | - Lu Liu
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| | - Shuo Huang
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| | - Ning Li
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| | - Hongbin Liu
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| | - Xiuliang Ding
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| | - Qinglong Song
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| | - Shiyan Qiao
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture and Rural Affairs Feed Industry CenterChina Agricultural University Beijing P.R. China
- Beijing Key Laboratory of Biofeed Additives Beijing P.R. China
| |
Collapse
|
5
|
Amaya E, Alarcón L, Martín-Tapia D, Cuellar-Pérez F, Cano-Cortina M, Ortega-Olvera JM, Cisneros B, Rodriguez AJ, Gamba G, González-Mariscal L. Activation of the Ca 2+ sensing receptor and the PKC/WNK4 downstream signaling cascade induces incorporation of ZO-2 to tight junctions and its separation from 14-3-3. Mol Biol Cell 2019; 30:2377-2398. [PMID: 31318316 PMCID: PMC6741067 DOI: 10.1091/mbc.e18-09-0591] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Zonula occludens-2 (ZO-2) is a tight junction (TJ) cytoplasmic protein, whose localization varies according to cell density and Ca2+ in the media. In cells cultured in low calcium (LC), ZO-2 displays a diffuse cytoplasmic distribution, but activation of the Ca2+ sensing receptor (CaSR) with Gd3+ triggers the appearance of ZO-2 at the cell borders. CaSR downstream signaling involves activation of protein kinase C, which phosphorylates and activates with no lysine kinase-4 that phosphorylates ZO-2 inducing its concentration at TJs. In LC, ZO-2 is protected from degradation by association to 14-3-3 proteins. When monolayers are transferred to normal calcium, the complexes ZO-2/14-3-3ζ and ZO-2/14-3-3σ move to the cell borders and dissociate. The 14-3-3 proteins are then degraded in proteosomes, whereas ZO-2 integrates to TJs. From the plasma membrane residual ZO-2 is endocyted and degradaded in lysosomes. The unique region 2 of ZO-2, and S261 located within a nuclear localization signal, are critical for the interaction with 14-3-3 ζ and σ and for the efficient nuclear importation of ZO-2. These results explain the molecular mechanism through which extracellular Ca2+ triggers the appearance of ZO-2 at TJs in epithelial cells and reveal the novel interaction between ZO-2 and 14-3-3 proteins, which is critical for ZO-2 protection and intracellular traffic.
Collapse
Affiliation(s)
- Elida Amaya
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Mexico City 07360, Mexico
| | - Lourdes Alarcón
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Mexico City 07360, Mexico
| | - Dolores Martín-Tapia
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Mexico City 07360, Mexico
| | - Francisco Cuellar-Pérez
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Mexico City 07360, Mexico
| | - Misael Cano-Cortina
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Mexico City 07360, Mexico
| | - Jose Mario Ortega-Olvera
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Mexico City 07360, Mexico
| | - Bulmaro Cisneros
- Department of Genetics and Molecular Biology, Mexico City 07360, Mexico
| | - Alexis J Rodriguez
- Department of Biological Science, Rutgers, The State University of New Jersey, Newark, NJ 07102
| | - Gerardo Gamba
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City 14080, México.,Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City 14080, Mexico.,Tecnológico de Monterrey, Escuela de Medicina y Ciencias de la Salud, 64710 Monterrey, Nuevo Leon, México
| | - Lorenza González-Mariscal
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Mexico City 07360, Mexico
| |
Collapse
|
6
|
Calatayud M, Dezutter O, Hernandez-Sanabria E, Hidalgo-Martinez S, Meysman FJR, Van de Wiele T. Development of a host-microbiome model of the small intestine. FASEB J 2018; 33:3985-3996. [PMID: 30521380 DOI: 10.1096/fj.201801414r] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The intestinal epithelium plays an essential role in the balance between tolerant and protective immune responses to infectious agents. In vitro models do not typically consider the innate immune response and gut microbiome in detail, so these models do not fully mimic the physiologic aspects of the small intestine. We developed and characterized a long-term in vitro model containing enterocyte, goblet, and immune-like cells exposed to a synthetic microbial community representative of commensal inhabitants of the small intestine. This model showed differential responses toward a synthetic microbial community of commensal bacterial inhabitants of the small intestine in the absence or presence of LPS from Escherichia coli O111:B4. Simultaneous exposure to LPS and microbiota induced impaired epithelial barrier function; increased production of IL-8, IL-6, TNF-α, and C-X-C motif chemokine ligand 16; and augmented differentiation and adhesion of macrophage-like cells and the overexpression of dual oxidase 2 and TLR-2 and -4 mRNA. In addition, the model demonstrated the ability to assess the adhesion of specific bacterial strains from the synthetic microbial community-more specifically, Veillonella parvula-to the simulated epithelium. This novel in vitro model may assist in overcoming sampling and retrieval difficulties when studying host-microbiome interactions in the small intestine.-Calatayud, M., Dezutter, O., Hernandez-Sanabria, E., Hidalgo-Martinez, S., Meysman, F. J. R., Van de Wiele, T. Development of a host-microbiome model of the small intestine.
Collapse
Affiliation(s)
- Marta Calatayud
- Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
| | - Olivier Dezutter
- Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
| | | | - Silvia Hidalgo-Martinez
- Department of Biology, Ecosystem Management Research Group (ECOBE), University of Antwerp, Wilrijk, Belgium; and
| | - Filip J R Meysman
- Department of Biology, Ecosystem Management Research Group (ECOBE), University of Antwerp, Wilrijk, Belgium; and.,Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Tom Van de Wiele
- Center for Microbial Ecology and Technology (CMET), Ghent University, Ghent, Belgium
| |
Collapse
|
7
|
Patra AK, Amasheh S, Aschenbach JR. Modulation of gastrointestinal barrier and nutrient transport function in farm animals by natural plant bioactive compounds – A comprehensive review. Crit Rev Food Sci Nutr 2018; 59:3237-3266. [DOI: 10.1080/10408398.2018.1486284] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Amlan Kumar Patra
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, Berlin, Germany
- Institute of Animal Nutrition, West Bengal University of Animal and Fishery Sciences, 37 K. B. Sarani, Belgachia, Kolkata, India
| | - Salah Amasheh
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, Berlin, Germany
| | - Jörg Rudolf Aschenbach
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, Berlin, Germany
| |
Collapse
|
8
|
Yang G, Bibi S, Du M, Suzuki T, Zhu MJ. Regulation of the intestinal tight junction by natural polyphenols: A mechanistic perspective. Crit Rev Food Sci Nutr 2018; 57:3830-3839. [PMID: 27008212 DOI: 10.1080/10408398.2016.1152230] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Impairment of the epithelial barrier function is closely linked to the pathogenesis of various gastrointestinal diseases, food allergies, type I diabetes, and other systematic diseases. Plant-derived polyphenols are natural secondary metabolites and exert various physiological benefits, including anti-inflammatory, anti-oxidative, anti-carcinogenic, and anti-aging effects. Recent studies also show the role of plant polyphenols in regulation of the intestinal barrier and prevention of intestinal inflammatory diseases. Here we summarize the regulatory pathways and mediators linking polyphenols to their beneficial effects on tight junction and gut epithelial barrier functions, and provide useful information about using polyphenols as nutraceuticals for intestinal diseases.
Collapse
Affiliation(s)
- Guan Yang
- a School of Food Science , Washington State University , Pullman , Washington , USA
| | - Shima Bibi
- a School of Food Science , Washington State University , Pullman , Washington , USA
| | - Min Du
- b Department of Animal Science , Washington State University , Pullman , Washington , USA
| | - Takuya Suzuki
- c Department of Biofunctional Science and Technology , Hiroshima University , Higashi-Hiroshima , Japan
| | - Mei-Jun Zhu
- a School of Food Science , Washington State University , Pullman , Washington , USA
| |
Collapse
|
9
|
Kurashima Y, Kiyono H. Mucosal Ecological Network of Epithelium and Immune Cells for Gut Homeostasis and Tissue Healing. Annu Rev Immunol 2017; 35:119-147. [PMID: 28125357 DOI: 10.1146/annurev-immunol-051116-052424] [Citation(s) in RCA: 184] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The intestinal epithelial barrier includes columnar epithelial, Paneth, goblet, enteroendocrine, and tuft cells as well as other cell populations, all of which contribute properties essential for gastrointestinal homeostasis. The intestinal mucosa is covered by mucin, which contains antimicrobial peptides and secretory IgA and prevents luminal bacteria, fungi, and viruses from stimulating intestinal immune responses. Conversely, the transport of luminal microorganisms-mediated by M, dendritic, and goblet cells-into intestinal tissues facilitates the harmonization of active and quiescent mucosal immune responses. The bacterial population within gut-associated lymphoid tissues creates the intratissue cohabitations for harmonized mucosal immunity. Intermolecular and intercellular communication among epithelial, immune, and mesenchymal cells creates an environment conducive for epithelial regeneration and mucosal healing. This review summarizes the so-called intestinal mucosal ecological network-the complex but vital molecular and cellular interactions of epithelial mesenchymal cells, immune cells, and commensal microbiota that achieve intestinal homeostasis, regeneration, and healing.
Collapse
Affiliation(s)
- Yosuke Kurashima
- Division of Mucosal Immunology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; .,International Research and Development Center for Mucosal Vaccines, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.,Institute for Global Prominent Research, Chiba University, Chiba 260-8670, Japan.,Department of Mucosal Immunology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.,Department of Innovative Medicine, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.,Chiba University-UC San Diego Center for Mucosal Immunology, Allergy, and Vaccine, La Jolla, CA 92093
| | - Hiroshi Kiyono
- Division of Mucosal Immunology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; .,International Research and Development Center for Mucosal Vaccines, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.,Chiba University-UC San Diego Center for Mucosal Immunology, Allergy, and Vaccine, La Jolla, CA 92093.,Department of Immunology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| |
Collapse
|
10
|
The role of intestinal oxalate transport in hyperoxaluria and the formation of kidney stones in animals and man. Urolithiasis 2016; 45:89-108. [PMID: 27913853 DOI: 10.1007/s00240-016-0952-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 11/22/2016] [Indexed: 12/26/2022]
Abstract
The intestine exerts a considerable influence over urinary oxalate in two ways, through the absorption of dietary oxalate and by serving as an adaptive extra-renal pathway for elimination of this waste metabolite. Knowledge of the mechanisms responsible for oxalate absorption and secretion by the intestine therefore have significant implications for understanding the etiology of hyperoxaluria, as well as offering potential targets for future treatment strategies for calcium oxalate kidney stone disease. In this review, we present the recent developments and advances in this area over the past 10 years, and put to the test some of the new ideas that have emerged during this time, using human and mouse models. A key focus for our discussion are the membrane-bound anion exchangers, belonging to the SLC26 gene family, some of which have been shown to participate in transcellular oxalate absorption and secretion. This has offered the opportunity to not only examine the roles of these specific transporters, revealing their importance to oxalate homeostasis, but to also probe the relative contributions made by the active transcellular and passive paracellular components of oxalate transport across the intestine. We also discuss some of the various physiological stimuli and signaling pathways which have been suggested to participate in the adaptation and regulation of intestinal oxalate transport. Finally, we offer an update on research into Oxalobacter formigenes, alongside recent investigations of other oxalate-degrading gut bacteria, in both laboratory animals and humans.
Collapse
|
11
|
Fermented Herbal Formulas KIOM-MA128 Ameliorate IL-6-Induced Intestinal Barrier Dysfunction in Colon Cancer Cell Line. Mediators Inflamm 2016; 2016:6189590. [PMID: 27980357 PMCID: PMC5131250 DOI: 10.1155/2016/6189590] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/24/2016] [Accepted: 10/26/2016] [Indexed: 02/07/2023] Open
Abstract
Inflammatory bowel disease (IBD) comprises Crohn's disease (CD) and ulcerative colitis (UC). IBD increases the risk of colorectal cancer (CRC), depending on the extent and duration of intestinal inflammation. Increased IL-6 expression has been reported in IBD patients, which may be associated with intestinal barrier function through discontinuous tight junction (TJ). KIOM-MA is a specific agent for allergic diseases and cancer, and it is composed of several plants; these herbs have been used in traditional oriental medicine. We fermented KIOM-MA, the product of KIOM-MA128, using probiotics to improve the therapeutic efficacy via the absorption and bioavailability of the active ingredients. In this study, we demonstrated that KIOM-MA/MA128 exhibited anticolitis effects via the modulation of TJ protein. Interleukin-6 resulted in a dose-dependent decrease in the TER and an increase in the FITC-dextran permeability; however, pretreatment with 400 µg/ml KIOM-MA/MA128 resulted in a significant increase in the TER and a decrease in the FITC-dextran permeability via IL-6 induction. Furthermore, protein and mRNA TJ levels remained stable after pretreatment with 400 µg/ml KIOM-MA/MA128. Moreover, KIOM-MA/MA128 suppressed the expression of PLCγ1 and PKC. Taken together, these findings suggest novel information and clue of the anticolitis effects of KIOM-MA128 via regulation of tight junction.
Collapse
|
12
|
Ling KH, Wan MLY, El-Nezami H, Wang M. Protective Capacity of Resveratrol, a Natural Polyphenolic Compound, against Deoxynivalenol-Induced Intestinal Barrier Dysfunction and Bacterial Translocation. Chem Res Toxicol 2016; 29:823-33. [DOI: 10.1021/acs.chemrestox.6b00001] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Ka-Ho Ling
- School
of Biological Sciences, Faculty of Science, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam, Hong Kong
| | - Murphy Lam Yim Wan
- School
of Biological Sciences, Faculty of Science, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam, Hong Kong
| | - Hani El-Nezami
- School
of Biological Sciences, Faculty of Science, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam, Hong Kong
- Institute
of Public Health and Clinical Nutrition, University of Eastern Finland, FI-70211 Kuopio, Finland
| | - Mingfu Wang
- School
of Biological Sciences, Faculty of Science, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam, Hong Kong
| |
Collapse
|
13
|
de Vallière C, Vidal S, Clay I, Jurisic G, Tcymbarevich I, Lang S, Ludwig MG, Okoniewski M, Eloranta JJ, Kullak-Ublick GA, Wagner CA, Rogler G, Seuwen K. The pH-sensing receptor OGR1 improves barrier function of epithelial cells and inhibits migration in an acidic environment. Am J Physiol Gastrointest Liver Physiol 2015. [PMID: 26206859 DOI: 10.1152/ajpgi.00408.2014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The pH-sensing receptor ovarian cancer G protein-coupled receptor 1 (OGR1; GPR68) is expressed in the gut. Inflammatory bowel disease is typically associated with a decrease in local pH, which may lead to altered epithelial barrier function and subsequent gastrointestinal repair involving epithelial cell adhesion and migration. As the mechanisms underlying the response to pH changes are not well understood, we have investigated OGR1-mediated, pH-dependent signaling pathways in intestinal epithelial cells. Caco-2 cells stably overexpressing OGR1 were created and validated as tools to study OGR1 signaling. Barrier function, migration, and proliferation were measured using electric cell-substrate impedance-sensing technology. Localization of the tight junction proteins zonula occludens protein 1 and occludin and the rearrangement of cytoskeletal actin were examined by confocal microscopy. Paracellular permeability and protein and gene expression analysis using DNA microarrays were performed on filter-grown Caco-2 monolayers. We report that an acidic pH shift from pH 7.8 to 6.6 improved barrier function and stimulated reorganization of filamentous actin with prominent basal stress fiber formation. Cell migration and proliferation during in vitro wound healing were inhibited. Gene expression analysis revealed significant upregulation of genes related to cytoskeleton remodeling, cell adhesion, and growth factor signaling. We conclude that acidic extracellular pH can have a signaling function and impact the physiology of intestinal epithelial cells. The deconstruction of OGR1-dependent signaling may aid our understanding of mucosal inflammation mechanisms.
Collapse
Affiliation(s)
- Cheryl de Vallière
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland; Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Solange Vidal
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Ieuan Clay
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Giorgia Jurisic
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Irina Tcymbarevich
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Silvia Lang
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | | | - Michal Okoniewski
- Functional Genomics Center, University of Zurich, Zurich, Switzerland
| | - Jyrki J Eloranta
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, Zurich, Switzerland
| | - Gerd A Kullak-Ublick
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, Zurich, Switzerland
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland; and Zurich Center for Integrative Human Physiology, Zurich, Switzerland
| | - Gerhard Rogler
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, Zurich, Switzerland
| | - Klaus Seuwen
- Novartis Institutes for Biomedical Research, Basel, Switzerland;
| |
Collapse
|
14
|
Vogt LM, Meyer D, Pullens G, Faas MM, Venema K, Ramasamy U, Schols HA, de Vos P. Toll-like receptor 2 activation by β2→1-fructans protects barrier function of T84 human intestinal epithelial cells in a chain length-dependent manner. J Nutr 2014; 144:1002-8. [PMID: 24790027 DOI: 10.3945/jn.114.191643] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Dietary fiber intake is associated with lower incidence and mortality from disease, but the underlying mechanisms of these protective effects are unclear. We hypothesized that β2→1-fructan dietary fibers confer protection on intestinal epithelial cell barrier function via Toll-like receptor 2 (TLR2), and we studied whether β2→1-fructan chain-length differences affect this process. T84 human intestinal epithelial cell monolayers were incubated with 4 β2→1-fructan formulations of different chain-length compositions and were stimulated with the proinflammatory phorbol 12-myristate 13-acetate (PMA). Transepithelial electrical resistance (TEER) was analyzed by electric cell substrate impedance sensing (ECIS) as a measure for tight junction-mediated barrier function. To confirm TLR2 involvement in barrier modulation by β2→1-fructans, ECIS experiments were repeated using TLR2 blocking antibody. After preincubation of T84 cells with short-chain β2→1-fructans, the decrease in TEER as induced by PMA (62.3 ± 5.2%, P < 0.001) was strongly attenuated (15.2 ± 8.8%, P < 0.01). However, when PMA was applied first, no effect on recovery was observed during addition of the fructans. By blocking TLR2 on the T84 cells, the protective effect of short-chain β2→1-fructans was substantially inhibited. Stimulation of human embryonic kidney human TLR2 reporter cells with β2→1-fructans induced activation of nuclear factor kappa-light-chain-enhancer of activated B cells, confirming that β2→1-fructans are specific ligands for TLR2. To conclude, β2→1-fructans exert time-dependent and chain length-dependent protective effects on the T84 intestinal epithelial cell barrier mediated via TLR2. These results suggest that TLR2 located on intestinal epithelial cells could be a target of β2→1-fructan-mediated health effects.
Collapse
Affiliation(s)
- Leonie M Vogt
- Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands;
| | | | - Gerdie Pullens
- Cosun Food Technology Centre, Roosendaal, The Netherlands
| | - Marijke M Faas
- Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Koen Venema
- TNO Quality of Life, Department of Biosciences, Zeist, The Netherlands; and
| | - Uttara Ramasamy
- Laboratory of Food Chemistry, Wageningen University, Wageningen, The Netherlands
| | - Henk A Schols
- Laboratory of Food Chemistry, Wageningen University, Wageningen, The Netherlands
| | - Paul de Vos
- Immunoendocrinology, Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| |
Collapse
|
15
|
Quiros M, Alarcón L, Ponce A, Giannakouros T, González-Mariscal L. The intracellular fate of zonula occludens 2 is regulated by the phosphorylation of SR repeats and the phosphorylation/O-GlcNAcylation of S257. Mol Biol Cell 2013; 24:2528-43. [PMID: 23804652 PMCID: PMC3744950 DOI: 10.1091/mbc.e13-04-0224] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
ZO-2 nuclear import and accumulation in speckles is regulated by phosphorylation of its SR repeats by SRPK1 in a process initiated by EGF activation of AKT. ZO-2 nuclear exportation is favored by O-GlcNAc of S257 at the nucleus, whereas maturation of tight junctions is accompanied by ZO-2 phosphorylation at S257 by PKCζ. Zona occludens 2 (ZO-2) has a dual localization. In confluent epithelia, ZO-2 is present at tight junctions (TJs), whereas in sparse proliferating cells it is also found at the nucleus. Previously we demonstrated that in sparse cultures, newly synthesized ZO-2 travels to the nucleus before reaching the plasma membrane. Now we find that in confluent cultures newly synthesized ZO-2 goes directly to the plasma membrane. Epidermal growth factor induces through AKT activation the phosphorylation of the kinase for SR repeats, serine arginine protein kinase 1, which in turn phosphorylates ZO-2, which contains 16 SR repeats. This phosphorylation induces ZO-2 entry into the nucleus and accumulation in speckles. ZO-2 departure from the nucleus requires intact S257, and stabilizing the β-O-linked N-acetylglucosylation (O-GlcNAc) of S257 with O-(2-acetamido-2-deoxy-d-glucopyranosylidene)amino-N-phenylcarbamate, an inhibitor of O-GlcNAcase, triggers nuclear exportation and proteosomal degradation of ZO-2. At the plasma membrane ZO-2 is not O-GlcNAc, and instead, as TJs mature, it becomes phosphorylated at S257 by protein kinase Cζ. This late phosphorylation of S257 is required for the correct cytoarchitecture to develop, as cells transfected with ZO-2 mutant S257A or S257E form aberrant cysts with multiple lumens. These results reveal novel posttranslational modifications of ZO-2 that regulate the intracellular fate of this protein.
Collapse
Affiliation(s)
- Miguel Quiros
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies Cinvestav, Mexico City 07000, Mexico Department of Chemistry, Aristotele University of Thessaloniki, Thessaloniki 54621, Greece
| | | | | | | | | |
Collapse
|
16
|
Oxidative stress mediates the disruption of airway epithelial tight junctions through a TRPM2-PLCγ1-PKCα signaling pathway. Int J Mol Sci 2013; 14:9475-86. [PMID: 23629676 PMCID: PMC3676794 DOI: 10.3390/ijms14059475] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 03/18/2013] [Accepted: 04/16/2013] [Indexed: 11/16/2022] Open
Abstract
Oxidative stress has been implicated as an important contributing factor in the pathogenesis of several pulmonary inflammatory diseases. Previous studies have indicated a relationship between oxidative stress and the attenuation of epithelial tight junctions (TJs). In Human Bronchial Epithelial-16 cells (16HBE), we demonstrated the degradation of zonula occludens-1 (ZO-1), and claudin-2 exhibited a great dependence on the activation of the transient receptor potential melastatin (TRPM) 2 channel, phospholipase Cγ1 (PLCγ1) and the protein kinase Cα (PKCα) signaling cascade.
Collapse
|
17
|
El-Hashash AHK, Turcatel G, Varma S, Berika M, Al Alam D, Warburton D. Eya1 protein phosphatase regulates tight junction formation in lung distal epithelium. J Cell Sci 2012; 125:4036-48. [PMID: 22685326 DOI: 10.1242/jcs.102848] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Little is known about the regulatory mechanisms underlying lung epithelial tight junction (TJ) assembly, which is inextricably linked to the preservation of epithelial polarity, and is highly coordinated by proteins that regulate epithelial cell polarity, such as aPKCζ. We recently reported that Eya1 phosphatase functions through aPKCζ-Notch1 signaling to control cell polarity in the lung epithelium. Here, we have extended these observations to TJ formation to demonstrate that Eya1 is crucial for the maintenance of TJ protein assembly in the lung epithelium, probably by controlling aPKCζ phosphorylation levels, aPKCζ-mediated TJ protein phosphorylation and Notch1-Cdc42 activity. Thus, TJs are disassembled after interfering with Eya1 function in vivo or during calcium-induced TJ assembly in vitro. These effects are reversed by reintroduction of wild-type Eya1 or partially inhibiting aPKCζ in Eya1siRNA cells. Moreover, genetic activation of Notch1 rescues Eya1(-/-) lung epithelial TJ defects. These findings uncover novel functions for the Eya1-aPKCζ-Notch1-Cdc42 pathway as a crucial regulatory mechanism of TJ assembly and polarity of the lung epithelium, providing a conceptual framework for future mechanistic and translational studies in this area.
Collapse
Affiliation(s)
- Ahmed H K El-Hashash
- Developmental Biology and Regenerative Medicine Program, Saban Research Institute, Children's Hospital Los Angeles, 4661 Sunset Boulevard, Los Angeles, CA 90027, USA.
| | | | | | | | | | | |
Collapse
|
18
|
Diraimondo TR, Klöck C, Khosla C. Interferon-γ activates transglutaminase 2 via a phosphatidylinositol-3-kinase-dependent pathway: implications for celiac sprue therapy. J Pharmacol Exp Ther 2012; 341:104-14. [PMID: 22228808 DOI: 10.1124/jpet.111.187385] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The mechanism for activation of extracellular transglutaminase 2 (TG2) in the small intestine remains a fundamental mystery in our understanding of celiac sprue pathogenesis. Using the T84 human enterocytic cell line, we show that interferon-γ (IFN-γ), the predominant cytokine secreted by gluten-reactive T cells in the celiac intestine, activates extracellular TG2 in a dose-dependent manner. IFN-γ mediated activation of TG2 requires phosphatidylinositol-3-kinase (PI3K) activity, but is uninfluenced by a number of other kinases reported to be active in T84 cells. Pharmacological inhibition of PI3K in the presence of IFN-γ prevents TG2 activation as well as the previously characterized increase in transepithelial permeability. Our findings therefore establish PI3K as an attractive target for celiac sprue therapy, a possibility that is underscored by the encouraging safety profiles of several PI3K inhibitors undergoing human clinical trials.
Collapse
Affiliation(s)
- Thomas R Diraimondo
- Department of Chemical Engineering, Stanford University, 380 Roth Way, Stanford, CA 94305, USA
| | | | | |
Collapse
|
19
|
Differential targeting of the E-Cadherin/β-Catenin complex by gram-positive probiotic lactobacilli improves epithelial barrier function. Appl Environ Microbiol 2011; 78:1140-7. [PMID: 22179242 DOI: 10.1128/aem.06983-11] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The intestinal ecosystem is balanced by dynamic interactions between resident and incoming microbes, the gastrointestinal barrier, and the mucosal immune system. However, in the context of inflammatory bowel diseases (IBD), where the integrity of the gastrointestinal barrier is compromised, resident microbes contribute to the development and perpetuation of inflammation and disease. Probiotic bacteria have been shown to exert beneficial effects, e.g., enhancing epithelial barrier integrity. However, the mechanisms underlying these beneficial effects are only poorly understood. Here, we comparatively investigated the effects of four probiotic lactobacilli, namely, Lactobacillus acidophilus, L. fermentum, L. gasseri, and L. rhamnosus, in a T84 cell epithelial barrier model. Results of DNA microarray experiments indicating that lactobacilli modulate the regulation of genes encoding in particular adherence junction proteins such as E-cadherin and β-catenin were confirmed by quantitative reverse transcription-PCR (qRT-PCR). Furthermore, we show that epithelial barrier function is modulated by Gram-positive probiotic lactobacilli via their effect on adherence junction protein expression and complex formation. In addition, incubation with lactobacilli differentially influences the phosphorylation of adherence junction proteins and the abundance of protein kinase C (PKC) isoforms such as PKCδ that thereby positively modulates epithelial barrier function. Further insight into the underlying molecular mechanisms triggered by these probiotics might also foster the development of novel strategies for the treatment of gastrointestinal diseases (e.g., IBD).
Collapse
|
20
|
Rezaee F, Meednu N, Emo JA, Saatian B, Chapman TJ, Naydenov NG, De Benedetto A, Beck LA, Ivanov AI, Georas SN. Polyinosinic:polycytidylic acid induces protein kinase D-dependent disassembly of apical junctions and barrier dysfunction in airway epithelial cells. J Allergy Clin Immunol 2011; 128:1216-1224.e11. [PMID: 21996340 DOI: 10.1016/j.jaci.2011.08.035] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 08/25/2011] [Accepted: 08/29/2011] [Indexed: 12/21/2022]
Abstract
BACKGROUND Disruption of the epithelial barrier might be a risk factor for allergen sensitization and asthma. Viral respiratory tract infections are strongly associated with asthma exacerbation, but the effects of respiratory viruses on airway epithelial barrier function are not well understood. Many viruses generate double-stranded RNA, which can lead to airway inflammation and initiate an antiviral immune response. OBJECTIVES We investigated the effects of the synthetic double-stranded RNA polyinosinic:polycytidylic acid (polyI:C) on the structure and function of the airway epithelial barrier in vitro. METHODS 16HBE14o- human bronchial epithelial cells and primary airway epithelial cells at an air-liquid interface were grown to confluence on Transwell inserts and exposed to polyI:C. We studied epithelial barrier function by measuring transepithelial electrical resistance and paracellular flux of fluorescent markers and structure of epithelial apical junctions by means of immunofluorescence microscopy. RESULTS PolyI:C induced a profound decrease in transepithelial electrical resistance and increase in paracellular permeability. Immunofluorescence microscopy revealed markedly reduced junctional localization of zonula occludens-1, occludin, E-cadherin, β-catenin, and disorganization of junction-associated actin filaments. PolyI:C induced protein kinase D (PKD) phosphorylation, and a PKD antagonist attenuated polyI:C-induced disassembly of apical junctions and barrier dysfunction. CONCLUSIONS PolyI:C has a powerful and previously unsuspected disruptive effect on the airway epithelial barrier. PolyI:C-dependent barrier disruption is mediated by disassembly of epithelial apical junctions, which is dependent on PKD signaling. These findings suggest a new mechanism potentially underlying the associations between viral respiratory tract infections, airway inflammation, and allergen sensitization.
Collapse
Affiliation(s)
- Fariba Rezaee
- Division of Pediatric Pulmonary, Department of Pediatrics, University of Rochester Medical Center, Rochester, NY 14610, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Hassan HA, Cheng M, Aronson PS. Cholinergic signaling inhibits oxalate transport by human intestinal T84 cells. Am J Physiol Cell Physiol 2011; 302:C46-58. [PMID: 21956166 DOI: 10.1152/ajpcell.00075.2011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Urolithiasis remains a very common disease in Western countries. Seventy to eighty percent of kidney stones are composed of calcium oxalate, and minor changes in urinary oxalate affect stone risk. Intestinal oxalate secretion mediated by anion exchanger SLC26A6 plays a major constitutive role in limiting net absorption of ingested oxalate, thereby preventing hyperoxaluria and calcium oxalate urolithiasis. Using the relatively selective PKC-δ inhibitor rottlerin, we had previously found that PKC-δ activation inhibits Slc26a6 activity in mouse duodenal tissue. To identify a model system to study physiologic agonists upstream of PKC-δ, we characterized the human intestinal cell line T84. Knockdown studies demonstrated that endogenous SLC26A6 mediates most of the oxalate transport by T84 cells. Cholinergic stimulation with carbachol modulates intestinal ion transport through signaling pathways including PKC activation. We therefore examined whether carbachol affects oxalate transport in T84 cells. We found that carbachol significantly inhibited oxalate transport by T84 cells, an effect blocked by rottlerin. Carbachol also led to significant translocation of PKC-δ from the cytosol to the membrane of T84 cells. Using pharmacological inhibitors, we observed that carbachol inhibits oxalate transport through the M(3) muscarinic receptor and phospholipase C. Utilizing the Src inhibitor PP2 and phosphorylation studies, we found that the observed regulation downstream of PKC-δ is partially mediated by c-Src. Biotinylation studies revealed that carbachol inhibits oxalate transport by reducing SLC26A6 surface expression. We conclude that carbachol negatively regulates oxalate transport by reducing SLC26A6 surface expression in T84 cells through signaling pathways including the M(3) muscarinic receptor, phospholipase C, PKC-δ, and c-Src.
Collapse
Affiliation(s)
- Hatim A Hassan
- Section of Nephrology, Dept. of Medicine, The Univ. of Chicago, 5841 S. Maryland Ave., MC5100, Chicago, IL 60637, USA.
| | | | | |
Collapse
|
22
|
Ulluwishewa D, Anderson RC, McNabb WC, Moughan PJ, Wells JM, Roy NC. Regulation of tight junction permeability by intestinal bacteria and dietary components. J Nutr 2011; 141:769-76. [PMID: 21430248 DOI: 10.3945/jn.110.135657] [Citation(s) in RCA: 790] [Impact Index Per Article: 60.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The human intestinal epithelium is formed by a single layer of epithelial cells that separates the intestinal lumen from the underlying lamina propria. The space between these cells is sealed by tight junctions (TJ), which regulate the permeability of the intestinal barrier. TJ are complex protein structures comprised of transmembrane proteins, which interact with the actin cytoskeleton via plaque proteins. Signaling pathways involved in the assembly, disassembly, and maintenance of TJ are controlled by a number of signaling molecules, such as protein kinase C, mitogen-activated protein kinases, myosin light chain kinase, and Rho GTPases. The intestinal barrier is a complex environment exposed to many dietary components and many commensal bacteria. Studies have shown that the intestinal bacteria target various intracellular pathways, change the expression and distribution of TJ proteins, and thereby regulate intestinal barrier function. The presence of some commensal and probiotic strains leads to an increase in TJ proteins at the cell boundaries and in some cases prevents or reverses the adverse effects of pathogens. Various dietary components are also known to regulate epithelial permeability by modifying expression and localization of TJ proteins.
Collapse
Affiliation(s)
- Dulantha Ulluwishewa
- Food Nutrition Genomics Team, Agri-Foods and Health Section, Palmerston North 4442, New Zealand
| | | | | | | | | | | |
Collapse
|
23
|
Chen HQ, Shen TY, Zhou YK, Zhang M, Chu ZX, Hang XM, Qin HL. Lactobacillus plantarum consumption increases PepT1-mediated amino acid absorption by enhancing protein kinase C activity in spontaneously colitic mice. J Nutr 2010; 140:2201-6. [PMID: 20980636 DOI: 10.3945/jn.110.123265] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although probiotic consumption has generally been shown to have many beneficial effects for the prevention and treatment of inflammatory bowel disease, the effects of Lactobacillus plantarum (LP) on intestinal nutrient absorption, particularly oligopeptide transporter 1 (PepT1)-mediated absorption of dietary protein under inflammatory conditions, has not yet been characterized. In this study, we first investigated the effects of LP consumption on plasma amino acid concentrations and PepT1-mediated absorption of cephalexin in the small intestine of wild-type (WT) mice and interleukin-10 knockout (IL-10(-/-)) mice, a model of spontaneous colitis. We then analyzed expression and distribution of PepT1 and protein kinase C (PKC) activity in the jejunum of these mice. LP consumption (10(9) colony-forming units/0.5 mL) delivered by gavage once per day for 4 wk increased the total plasma amino acid concentration and the concentration of plasma cephalexin through enhancement of PepT1-mediated uptake in LP treated IL-10(-/-) mice compared with IL-10(-/-) mice. However, Western blotting and quantitative PCR analysis revealed no significant differences in PepT1 protein and mRNA expression between LP-treated and untreated mice. Additionally, immunofluorescence analysis showed that PepT1 did not appear to be mislocalized in IL-10(-/-) mice. Interestingly, IL-10(-/-) mice had significantly lower PKC activity and expression of phosphorylated PKC compared with WT mice, and these decreases could be prevented by LP treatment. These data suggest that consumption of LP enhances PepT1-mediated amino acid absorption, likely through alterations in PKC activity, as opposed to changes in expression or distribution of PepT1 in the small intestine of IL-10(-/-) mice.
Collapse
Affiliation(s)
- Hong-Qi Chen
- Department of General Surgery, Affiliated Sixth People's Hospital, Shanghai, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
24
|
Tang J, Bouyer P, Mykoniatis A, Buschmann M, Matlin KS, Matthews JB. Activated PKC{delta} and PKC{epsilon} inhibit epithelial chloride secretion response to cAMP via inducing internalization of the Na+-K+-2Cl- cotransporter NKCC1. J Biol Chem 2010; 285:34072-85. [PMID: 20732874 DOI: 10.1074/jbc.m110.137380] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The basolateral Na(+)-K(+)-2Cl(-) cotransporter (NKCC1) is a key determinant of transepithelial chloride secretion and dysregulation of chloride secretion is a common feature of many diseases including secretory diarrhea. We have previously shown that activation of protein kinase C (PKC) markedly reduces transepithelial chloride secretion in human colonic T84 cells, which correlates with both functional inhibition and loss of the NKCC1 surface expression. In the present study, we defined the specific roles of PKC isoforms in regulating epithelial NKCC1 and chloride secretion utilizing adenoviral vectors that express shRNAs targeting human PKC isoforms (α, δ, ε) (shPKCs) or LacZ (shLacZ, non-targeting control). After 72 h of adenoviral transduction, protein levels of the PKC isoforms in shPKCs-T84 cells were decreased by ∼90% compared with the shLacZ-control. Activation of PKCs by phorbol 12-myristate 13-acetate (PMA) caused a redistribution of NKCC1 immunostaining from the basolateral membrane to intracellular vesicles in both shLacZ- and shPKCα-T84 cells, whereas the effect of PMA was not observed in shPKCδ- and shPKCε- cells. These results were further confirmed by basolateral surface biotinylation. Furthermore, activation of PKCs by PMA inhibited cAMP-stimulated chloride secretion in the uninfected, shLacZ- and shPKCα-T84 monolayers, but the inhibitory effect was significantly attenuated in shPKCδ- and shPKCε-T84 monolayers. In conclusion, the activated novel isoforms PKCδ or PKCε, but not the conventional isoform PKCα, inhibits transepithelial chloride secretion through inducing internalization of the basolateral surface NKCC1. Our study reveals that the novel PKC isoform-regulated NKCC1 surface expression plays an important role in the regulation of chloride secretion.
Collapse
Affiliation(s)
- Jun Tang
- Department of Surgery, The University of Chicago, Chicago, Illinois 60637, USA
| | | | | | | | | | | |
Collapse
|
25
|
Rohilla A, Singh G, Singh M, Bala kumar P. Possible involvement of PKC-δ in the abrogated cardioprotective potential of ischemic preconditioning in hyperhomocysteinemic rat hearts. Biomed Pharmacother 2010; 64:195-202. [DOI: 10.1016/j.biopha.2009.04.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Revised: 03/29/2009] [Accepted: 04/01/2009] [Indexed: 01/31/2023] Open
|
26
|
Sun MK, Alkon DL. Protein kinase C activators as synaptogenic and memory therapeutics. Arch Pharm (Weinheim) 2010; 342:689-98. [PMID: 19899099 DOI: 10.1002/ardp.200900050] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The last decade has witnessed a rapid progress in understanding of the molecular cascades that may underlie memory and memory disorders. Among the critical players, activity of protein kinase C (PKC) isoforms is essential for many types of learning and memory and their dysfunction, and is critical in memory disorders. PKC inhibition and functional deficits lead to an impairment of various types of learning and memory, consistent with the observations that neurotoxic amyloid inhibits PKC activity and that transgenic animal models with PKCbeta deficit exhibit impaired capacity in cognition. In addition, PKC isozymes play a regulatory role in amyloid production and accumulation. Restoration of the impaired PKC signal pathway pharmacologically results in an enhanced memory capacity and synaptic remodeling / repair and synaptogenesis, and, therefore, represents a potentially important strategy for the treatment of memory disorders, including Alzheimer's dementia. The PKC activators, especially those that are isozyme-specific, are a new class of drug candidates that may be developed as future memory therapeutics.
Collapse
Affiliation(s)
- Miao-Kun Sun
- Blanchette Rockefeller Neurosciences Institute, Rockville, MD 20850, USA.
| | | |
Collapse
|
27
|
Chamorro D, Alarcón L, Ponce A, Tapia R, González-Aguilar H, Robles-Flores M, Mejía-Castillo T, Segovia J, Bandala Y, Juaristi E, González-Mariscal L. Phosphorylation of zona occludens-2 by protein kinase C epsilon regulates its nuclear exportation. Mol Biol Cell 2009; 20:4120-9. [PMID: 19625451 DOI: 10.1091/mbc.e08-11-1129] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Here, we have analyzed the subcellular destiny of newly synthesized tight junction protein zona occludens (ZO)-2. After transfection in sparse cells, 74% of cells exhibit ZO-2 at the nucleus, and after 18 h the value decreases to 17%. The mutation S369A located within the nuclear exportation signal 1 of ZO-2 impairs the nuclear export of the protein. Because Ser369 represents a putative protein kinase C (PKC) phosphorylation site, we tested the effect of PKC inhibition and stimulation on the nuclear export of ZO-2. Our results strongly suggest that the departure of ZO-2 from the nucleus is regulated by phosphorylation at Ser369 by novel PKCepsilon. To test the route taken by ZO-2 from synthesis to the plasma membrane, we devised a novel nuclear microinjection assay in which the nucleus served as a reservoir for anti-ZO-2 antibody. Through this assay, we demonstrate that a significant amount of newly synthesized ZO-2 goes into the nucleus and is later relocated to the plasma membrane. These results constitute novel information for understanding the mechanisms that regulate the intracellular fate of ZO-2.
Collapse
Affiliation(s)
- David Chamorro
- Departments of Physiology, Biophysics, and Neuroscience, Center for Research and Advanced Studies (CINVESTAV), Mexico, D.F., 07360, Mexico
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Ivanov AI, Samarin SN, Bachar M, Parkos CA, Nusrat A. Protein kinase C activation disrupts epithelial apical junctions via ROCK-II dependent stimulation of actomyosin contractility. BMC Cell Biol 2009; 10:36. [PMID: 19422706 PMCID: PMC2685374 DOI: 10.1186/1471-2121-10-36] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Accepted: 05/07/2009] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Disruption of epithelial cell-cell adhesions represents an early and important stage in tumor metastasis. This process can be modeled in vitro by exposing cells to chemical tumor promoters, phorbol esters and octylindolactam-V (OI-V), known to activate protein kinase C (PKC). However, molecular events mediating PKC-dependent disruption of epithelial cell-cell contact remain poorly understood. In the present study we investigate mechanisms by which PKC activation induces disassembly of tight junctions (TJs) and adherens junctions (AJs) in a model pancreatic epithelium. RESULTS Exposure of HPAF-II human pancreatic adenocarcinoma cell monolayers to either OI-V or 12-O-tetradecanoylphorbol-13-acetate caused rapid disruption and internalization of AJs and TJs. Activity of classical PKC isoenzymes was responsible for the loss of cell-cell contacts which was accompanied by cell rounding, phosphorylation and relocalization of the F-actin motor nonmuscle myosin (NM) II. The OI-V-induced disruption of AJs and TJs was prevented by either pharmacological inhibition of NM II with blebbistatin or by siRNA-mediated downregulation of NM IIA. Furthermore, AJ/TJ disassembly was attenuated by inhibition of Rho-associated kinase (ROCK) II, but was insensitive to blockage of MLCK, calmodulin, ERK1/2, caspases and RhoA GTPase. CONCLUSION Our data suggest that stimulation of PKC disrupts epithelial apical junctions via ROCK-II dependent activation of NM II, which increases contractility of perijunctional actin filaments. This mechanism is likely to be important for cancer cell dissociation and tumor metastasis.
Collapse
Affiliation(s)
- Andrei I Ivanov
- Department of Medicine, University of Rochester, Rochester, NY 14642, USA.
| | | | | | | | | |
Collapse
|
29
|
Phorbol ester enhances KAI1 transcription by recruiting Tip60/Pontin complexes. Neoplasia 2009; 10:1421-32, following 1432. [PMID: 19048121 DOI: 10.1593/neo.08850] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 09/11/2008] [Accepted: 09/12/2008] [Indexed: 12/31/2022] Open
Abstract
Down-regulation of the KAI1 (CD82) metastasis suppressor is common in advanced human cancer, but underlying mechanism(s) regulating KAI1 expression are only now being elucidated. Recent data provide evidence that low levels of KAI1 mRNA in LNCaP cells are caused by binding of beta-catenin/Reptin complexes to a specific motif in the proximal promoter, which prevents binding of Tip60/Pontin activator complexes to the same motif, thus inhibiting transcription. Here, we explored a pathway by which phorbol 12-myristate 13-acetate (PMA) up-regulates KAI1 transcription in LNCaP prostate cancer cells. Pretreatment with specific inhibitors showed that induction of KAI1 by PMA uses classic isoforms of protein kinase C (cPKC), is independent of Ras and Raf, and requires activation of MEK1/2 and ERK1/2, but does not involve p38MAPK. Induction of KAI1 transcription by PMA was associated with enhanced overall acetylation of histones H3 and H4, but only acetylation of H3 was blocked by a PKC inhibitor. Chromatin immunoprecipitation showed that PMA induces recruitment of Tip60/Pontin activator complexes to NFkappaB-p50 motifs in the proximal promoter, and this was blocked by a PKC inhibitor. These changes were not associated with differences in overall levels of Tip60, Pontin, beta-catenin, or Reptin protein expression but with PMA-induced nuclear translocation of Tip60.
Collapse
|
30
|
Wald FA, Oriolo AS, Mashukova A, Fregien NL, Langshaw AH, Salas PJI. Atypical protein kinase C (iota) activates ezrin in the apical domain of intestinal epithelial cells. J Cell Sci 2008; 121:644-54. [PMID: 18270268 DOI: 10.1242/jcs.016246] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Atypical protein kinase iota (PKCiota) is a key organizer of the apical domain in epithelial cells. Ezrin is a cytosolic protein that, upon activation by phosphorylation of T567, is localized under the apical membrane where it connects actin filaments to membrane proteins and recruits protein kinase A (PKA). To identify the kinase that phosphorylates ezrin T567 in simple epithelia, we analyzed the expression of active PKC and the appearance of T567-P during enterocyte differentiation in vivo. PKCiota phosphorylated ezrin on T567 in vitro, and in Sf9 cells that do not activate human ezrin. In CACO-2 human intestinal cells in culture, PKCiota co-immunoprecipitated with ezrin and was knocked down by shRNA expression. The resulting phenotype showed a modest decrease in total ezrin, but a steep decrease in T567 phosphorylation. The PKCiota-depleted cells showed fewer and shorter microvilli and redistribution of the PKA regulatory subunit. Expression of a dominant-negative form of PKCiota also decreased T567-P signal, and expression of a constitutively active PKCiota mutant showed depolarized distribution of T567-P. We conclude that, although other molecular mechanisms contribute to ezrin activation, apically localized phosphorylation by PKCiota is essential for the activation and normal distribution of ezrin at the early stages of intestinal epithelial cell differentiation.
Collapse
Affiliation(s)
- Flavia A Wald
- Department of Cell Biology and Anatomy, University of Miami Miller School of Medicine, Miami, FL 33135, USA
| | | | | | | | | | | |
Collapse
|
31
|
Park JA, Crews AL, Lampe WR, Fang S, Park J, Adler KB. Protein kinase C delta regulates airway mucin secretion via phosphorylation of MARCKS protein. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 171:1822-30. [PMID: 18055557 DOI: 10.2353/ajpath.2007.070318] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Mucin hypersecretion is a major pathological feature of many respiratory diseases, yet cellular mechanisms regulating secretion of mucin have not been fully elucidated. Previously, we reported that mucin hypersecretion induced by human neutrophil elastase involves activation of protein kinase C (PKC), specifically the delta-isoform (PKC delta). Here, we further investigated the role of PKC delta in mucin hypersecretion using both primary human bronchial epithelial cells and the human bronchial epithelial 1 cell line as in vitro model systems. Phorbol-12-myristate-13-acetate (PMA)-induced mucin hypersecretion was significantly attenuated by rottlerin, a PKC delta-selective inhibitor. Rottlerin also reduced PMA- or human neutrophil elastase-induced phosphorylation of myristoylated alanine-rich C kinase substrate (MARCKS) protein in these cells. Both secretion and MARCKS phosphorylation were significantly enhanced by the PKC delta activator bryostatin 1. A dominant-negative PKC delta construct (pEGFP-N1/PKC delta K376R) transfected into human bronchial epithelial 1 cells significantly attenuated both PMA-induced mucin secretion and phosphorylation of MARCKS, whereas transfection of a wild-type construct increased PKC delta and enhanced mucin secretion and MARCKS phosphorylation. Similar transfections of a dominant-negative or wild-type PKC epsilon construct did not affect either mucin secretion or MARCKS phosphorylation. The results suggest that PKC delta plays an important role in mucin secretion by airway epithelium via regulation of MARCKS phosphorylation.
Collapse
Affiliation(s)
- Jin-Ah Park
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough St., Raleigh, NC 27606, USA
| | | | | | | | | | | |
Collapse
|
32
|
Kanchanapoo J, Ao M, Prasad R, Moore C, Kay C, Piyachaturawat P, Rao MC. Role of protein kinase C-delta in the age-dependent secretagogue action of bile acids in mammalian colon. Am J Physiol Cell Physiol 2007; 293:C1851-61. [PMID: 17898130 DOI: 10.1152/ajpcell.00194.2007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of specific PKC isoforms in the regulation of epithelial Cl(-) secretion by Ca(2+)-dependent secretagogues remains controversial. In the developing rabbit distal colon, the bile acid taurodeoxycholate (TDC) acts via intracellular calcium to stimulate Cl(-) transport in adult, but not in young, animals, whereas the PKC activator phorbol dibutyrate (PDB) stimulates Cl(-) transport at all ages. We tested the hypothesis that specific PKC isoforms account for the age-specific effects of TDC. The effects of conventional (cPKC) and novel (nPKC) PKC-specific inhibitors on TDC- and PDB-stimulated Cl(-) transport in adult and weanling colonocytes were assessed by using 6-methoxy-quinolyl acetoethyl ester. In adult colonocytes, the cPKC inhibitor Gö-6976 inhibited PDB action but not TDC action, whereas the cPKC and nPKC inhibitor Gö-6850 blocked both TDC and PDB actions. Additionally, rottlerin and the PKC-delta-specific inhibitor peptide (deltaV1-1) inhibited TDC- and PDB-stimulated Cl(-) transport in adult colonocytes. Rottlerin also decreased TDC-stimulated short-circuit current in intact colonic epithelia. Only Gö-6976, but neither rottlerin nor deltaV1-1, inhibited PDB-stimulated transport in weanling colonocytes. Colonic lysates express PKC-alpha, -lambda, and -iota protein equally at all ages, but they do not express PKC-gamma or -theta at any age. Expression of PKC-beta and PKC-epsilon protein was newborn>adult>weanling, whereas PKC-delta was expressed in adult but not in weanling or newborn colonocytes. TDC (1.6-fold) and PDB (2.0-fold) stimulated PKC-delta enzymatic activity in adult colonocytes but failed to do so in weanling colonocytes. PKC-delta mRNA expression showed age dependence. Thus PKC-delta appears critical for the action of TDC in the adult colon, and its low expression in young animals may account for their inability to secrete in response to bile acids.
Collapse
Affiliation(s)
- Jainuch Kanchanapoo
- Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | | | | | | | | | | | | |
Collapse
|
33
|
Crosstalk of tight junction components with signaling pathways. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1778:729-56. [PMID: 17950242 DOI: 10.1016/j.bbamem.2007.08.018] [Citation(s) in RCA: 565] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 08/03/2007] [Accepted: 08/16/2007] [Indexed: 12/28/2022]
Abstract
Tight junctions (TJs) regulate the passage of ions and molecules through the paracellular pathway in epithelial and endothelial cells. TJs are highly dynamic structures whose degree of sealing varies according to external stimuli, physiological and pathological conditions. In this review we analyze how the crosstalk of protein kinase C, protein kinase A, myosin light chain kinase, mitogen-activated protein kinases, phosphoinositide 3-kinase and Rho signaling pathways is involved in TJ regulation triggered by diverse stimuli. We also report how the phosphorylation of the main TJ components, claudins, occludin and ZO proteins, impacts epithelial and endothelial cell function.
Collapse
|
34
|
D’Souza T, Indig FE, Morin PJ. Phosphorylation of claudin-4 by PKCepsilon regulates tight junction barrier function in ovarian cancer cells. Exp Cell Res 2007; 313:3364-75. [PMID: 17678893 PMCID: PMC2034282 DOI: 10.1016/j.yexcr.2007.06.026] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 06/15/2007] [Accepted: 06/28/2007] [Indexed: 11/27/2022]
Abstract
Claudin proteins belong to a large family of transmembrane proteins essential to the formation and maintenance of tight junctions (TJs). In ovarian cancer, TJ protein claudin-4 is frequently overexpressed and may have roles in survival and invasion, but the molecular mechanisms underlying its regulation are poorly understood. In this report, we show that claudin-4 can be phosphorylated by protein kinase C (PKC) at Thr189 and Ser194 in ovarian cancer cells and overexpression of a claudin-4 mutant protein mimicking the phosphorylated state results in the disruption of the barrier function. Furthermore, upon phorbol ester-mediated PKC activation of OVCA433 cells, TJ strength is decreased and claudin-4 localization is altered. Analyses using PKC inhibitors and siRNA suggest that PKCepsilon, an isoform typically expressed in ovarian cancer cells, may be important in the TPA-mediated claudin-4 phosphorylation and weakening of the TJs. Furthermore, immunofluorescence studies showed that claudin-4 and PKCepsilon are co-localized at the TJs in these cells. The modulation of claudin-4 activity by PKCepsilon may not only provide a mechanism for disrupting TJ function in ovarian cancer, but may also be important in the regulation of TJ function in normal epithelial cells.
Collapse
Affiliation(s)
- Theresa D’Souza
- Laboratory of Cellular and Molecular Biology, National Institute on Aging, Baltimore, MD 21224, USA
| | - Fred E. Indig
- Research Resources Branch, National Institute on Aging, MD 21224, USA
| | - Patrice J. Morin
- Laboratory of Cellular and Molecular Biology, National Institute on Aging, Baltimore, MD 21224, USA
- Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA
- *Correspondence: Patrice J. Morin, Laboratory of Cellular and Molecular Biology, Gerontology Research Center, NIA, NIH, 5600 Nathan Shock Drive, Baltimore MD 21224. Tel. 410 558 8506; Fax: 410 558 8386;
| |
Collapse
|
35
|
O'Mahony F, Alzamora R, Betts V, LaPaix F, Carter D, Irnaten M, Harvey BJ. Female gender-specific inhibition of KCNQ1 channels and chloride secretion by 17beta-estradiol in rat distal colonic crypts. J Biol Chem 2007; 282:24563-73. [PMID: 17556370 DOI: 10.1074/jbc.m611682200] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The estrogen sex steroid 17beta-estradiol rapidly inhibits secretagogue-stimulated cAMP-dependent Cl(-) secretion in the female rat distal colonic crypt by the inhibition of basolateral K(+) channels. In Ussing chamber studies, both the anti-secretory response and inhibition of basolateral K(+) current was shown to be attenuated by pretreatment with rottlerin, a PKCdelta-specific inhibitor. In whole cell patch-clamp analysis, 17beta-estradiol inhibited a chromanol 293B-sensitive KCNQ1 channel current in isolated female rat distal colonic crypts. Estrogen had no effect on KCNQ1 channel currents in colonic crypts isolated from male rats. Female distal colonic crypts expressed a significantly higher amount of PKCdelta in comparison to male tissue. PKCdelta and PKA were activated at 5 min in response to 17beta-estradiol in female distal colonic crypts only. Both PKCdelta- and PKA-associated with the KCNQ1 channel in response to 17beta-estradiol in female distal colonic crypts, and no associations were observed in crypts from males. PKA activation, association with KCNQ1, and phosphorylation of the channel were regulated by PKCdelta as the responses were blocked by pretreatment with rottlerin. Taken together, our experiments have identified the molecular targets underlying the anti-secretory response to estrogen involving the inhibition of KCNQ1 channel activity via PKCdelta- and PKA-dependent signaling pathways. This is a novel gender-specific mechanism of regulation of an ion channel by estrogen. The anti-secretory response described in this study provides molecular insights whereby estrogen causes fluid retention effects in the female during periods of high circulating plasma estrogen levels.
Collapse
Affiliation(s)
- Fiona O'Mahony
- Department of Molecular Medicine, Beaumont Hospital, Royal College of Surgeons in Ireland, Dublin 9, Ireland.
| | | | | | | | | | | | | |
Collapse
|
36
|
Reynolds A, Parris A, Evans LA, Lindqvist S, Sharp P, Lewis M, Tighe R, Williams MR. Dynamic and differential regulation of NKCC1 by calcium and cAMP in the native human colonic epithelium. J Physiol 2007; 582:507-24. [PMID: 17478539 PMCID: PMC2075325 DOI: 10.1113/jphysiol.2007.129718] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The capacity of the intestine to secrete fluid is dependent on the basolateral Na(+)-K(+)-2Cl(-) co-transporter (NKCC1). Given that cAMP and Ca(2+) signals promote sustained and transient episodes of fluid secretion, respectively, this study investigated the differential regulation of functional NKCC1 membrane expression in the native human colonic epithelium. Tissue sections and colonic crypts were obtained from sigmoid rectal biopsy tissue samples. Cellular location of NKCC1, Na(+)-K(+)-ATPase, M3 muscarinic acetylcholine receptor (M(3)AChR) and lysosomes was examined by immunolabelling techniques. NKCC1 activity (i.e. bumetanide-sensitive uptake), intracellular Ca(2+) and cell volume were assessed by 2',7'-bis(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF), Fura-2 and differential interference contrast/calcein imaging. Unstimulated NKCC1 was expressed on basolateral membranes and exhibited a topological expression gradient, predominant at the crypt base. Cholinergic Ca(2+) signals initiated at the crypt base and spread along the crypt axis. In response, NKCC1 underwent a Ca(2+)-dependent 4 h cycle of recruitment to basolateral membranes, activation, internalization, degradation and re-expression. Internalization was prevented by the epidermal growth factor receptor kinase inhibitor tyrphostin-AG1478, and re-expression was prohibited by the protein synthesis inhibitor cylcoheximide; the lysosome inhibitor chloroquine promoted accumulation of NKCC1 vesicles. NKCC1 internalization and re-expression were accompanied by secretory volume decrease and bumetanide-sensitive regulatory volume increase, respectively. In contrast, forskolin (i.e. cAMP elevation)-stimulated NKCC1 activity was sustained, and membrane expression and cell volume remained constant. Co-stimulation with forskolin and acetylcholine promoted dramatic recruitment of NKCC1 to basolateral membranes and prolonged the cycle of co-transporter activation, internalization and re-expression. In conclusion, persistent NKCC1 activation by cAMP is constrained by a Ca(2+)-dependent cycle of co-transporter internalization, degradation and re-expression; this is a novel mechanism to limit intestinal fluid loss.
Collapse
Affiliation(s)
- Amy Reynolds
- School of Biological Sciences, University of East Anglia, Norwich, Norfolk NR4 7TJ, UK
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Baglole CJ, Sigalet DL, Meddings JB. Alpha1-adrenoceptors down-regulate ClC-2 chloride channels in epithelial cells from the acutely denervated jejunum. Eur J Pharmacol 2007; 565:202-6. [PMID: 17466294 DOI: 10.1016/j.ejphar.2007.03.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Revised: 03/08/2007] [Accepted: 03/14/2007] [Indexed: 10/23/2022]
Abstract
Acute sympathetic denervation of the small intestine up-regulates alpha1-adrenoceptors on villus enterocytes and activation of these alpha1-adrenoceptors inhibits chloride secretion. We tested whether alpha1-adrenoceptor-mediated inhibition of chloride secretion was the result of reduced ClC-2 chloride channel expression. Phorbol myristate acetate (PMA) (a protein kinase C (PKC) activator) had no effect on ClC-2 levels. In contrast, alpha1-adrenoceptor activation significantly decreased ClC-2 protein levels in both the villus (1.58+/-0.19 to 0.75+/-0.19 arbitrary units) and crypt (1.69+/-0.15 to 0.37+/-0.23 arbitrary units) epithelial cells from the acutely denervated jejunum but not innervated controls. These data suggest that inhibition of chloride secretion following alpha1-adrenoceptor activation in the acutely denervated small intestine may be through ClC-2 down-regulation.
Collapse
Affiliation(s)
- Carolyn J Baglole
- Gastrointestinal Research Group, University of Calgary, 3330 Hospital Drive, Calgary, Alberta, Canada T2N 4N1.
| | | | | |
Collapse
|
38
|
McKay DM, Watson JL, Wang A, Caldwell J, Prescott D, Ceponis PMJ, Di Leo V, Lu J. Phosphatidylinositol 3'-kinase is a critical mediator of interferon-gamma-induced increases in enteric epithelial permeability. J Pharmacol Exp Ther 2006; 320:1013-22. [PMID: 17178936 DOI: 10.1124/jpet.106.113639] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The epithelial lining of mucosal surfaces acts as a barrier to regulate the entry of antigen and pathogens. Nowhere is this function of the contiguous epithelium more important than in the gut, which is continually exposed to a huge antigenic load and, in the colon, an immense commensal microbiota. We assessed the intracellular signaling events that underlie interferon (IFN) gamma-induced increases in epithelial permeability using monolayers of the human colonic T84 epithelial cell line. Confluent epithelial monolayers on semipermeable supports were treated with IFNgamma (20 ng/ml), and barrier function was assessed 48 h later by measuring transepithelial electrical resistance (TER: reflects passive ion flux), fluxes of (51)Cr-EDTA and horseradish peroxidase (HRP), and transcytosis of noninvasive, nonpathogenic Escherichia coli (strain HB101). Exposure to IFNgamma decreased barrier function as assessed by all four markers. The phosphatidylinositol 3'-kinase (PI-3K) inhibitors, LY294002 [2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride] and wortmannin, did not affect baseline permeability characteristics but completely blocked the drop in TER, increased fluxes of (51)Cr-EDTA and HRP, and significantly reduced E. coli transcytosis evoked by IFNgamma. In addition, use of the pan-protein kinase C (PKC) inhibitor, bisindolylmaleimide I (5 muM), but not rottlerin (blocks PKCdelta), partially ameliorated the drop in TER and inhibited increased E. coli transcytosis. Addition of the PI-3K and PKC inhibitors to epithelia 6 h after IFNgamma exposure still prevented the increase in paracellular permeability but not E. coli transcytosis. Thus, IFNgamma-induced increases in epithelial paracellular and transcellular permeability are critically dependent on PI-3K activity, which may represent an epithelial-specific target to treat immune-mediated loss of barrier function.
Collapse
Affiliation(s)
- Derek M McKay
- Intestinal Disease Research Programme, Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Zyrek AA, Cichon C, Helms S, Enders C, Sonnenborn U, Schmidt MA. Molecular mechanisms underlying the probiotic effects of Escherichia coli Nissle 1917 involve ZO-2 and PKCzeta redistribution resulting in tight junction and epithelial barrier repair. Cell Microbiol 2006; 9:804-16. [PMID: 17087734 DOI: 10.1111/j.1462-5822.2006.00836.x] [Citation(s) in RCA: 289] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The probiotic Escherichia coli strain Nissle 1917 (EcN) has been used for decades in human medicine in Central Europe for the treatment and prevention of intestinal disorders and diseases. However, the molecular mechanisms underlying its beneficial effects are only partially understood. To identify molecular responses induced by EcN that might contribute to its probiotic properties polarized T84 cells were investigated employing DNA microarrays, quantitative RT-PCR, Western blotting, immunofluorescence and specific protein kinase C (PKC) inhibitors. Polarized T84 epithelial cell monolayers were used as a model to monitor barrier disruption by infection with the enteropathogenic E. coli (EPEC) strain E2348/69. Co-incubation of EPEC with EcN or addition of EcN following EPEC infection abolished barrier disruption and, moreover, restored barrier integrity as monitored by transepithelial resistance. DNA-microarray analysis of T84 cells incubated with EcN identified 300+ genes exhibiting altered expression. EcN altered the expression, distribution of zonula occludens-2 (ZO-2) protein and of distinct PKC isotypes. ZO-2 expression was enhanced in parallel to its redistribution towards the cell boundaries. This study provides evidence that EcN induces an overriding signalling effect leading to restoration of a disrupted epithelial barrier. This is transmitted via silencing of PKCzeta and the redistribution of ZO-2. We suggest that these properties contribute to the reported efficacy in the treatment of inflammatory bowel diseases and in part rationalize the probiotic nature of EcN.
Collapse
Affiliation(s)
- Agata A Zyrek
- Institut für Infektiologie, Zentrum für Molekularbiologie der Entzündung (ZMBE), Westfälische Wilhelms-Universität/Universitätsklinikum Münster, von-Esmarch-Str. 56, D-48149 Münster, Germany
| | | | | | | | | | | |
Collapse
|
40
|
Broughman JR, Sun L, Umar S, Scott J, Sellin JH, Morris AP. Chronic PKC-beta activation in HT-29 Cl.19a colonocytes prevents cAMP-mediated ion secretion by inhibiting apical membrane current generation. Am J Physiol Gastrointest Liver Physiol 2006; 291:G318-30. [PMID: 16574993 DOI: 10.1152/ajpgi.00355.2005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We investigated the effects of PKC-stimulating 12-deoxyphorbol 13-phenylacetate 20-acetate (DOPPA) and phorbol 12-myristate 13-acetate (PMA) phorbol esters on cAMP-dependent, forskolin (FSK)-stimulated, short-circuit Cl- current (ISC-cAMP) generation by colonocyte monolayers. These agonists elicited different actions depending on their dose and incubation time; PMA effects at the onset (<5 min) were independent of cAMP agonist and were characterized by transient anion-dependent transcellular and apical membrane ISC generation. DOPPA failed to elicit similar responses. Whereas chronic (24 h) exposure to both agents inhibited FSK-stimulated transcellular and apical membrane ISC-cAMP, the effects of DOPPA were more complex: this conventional PKC-beta-specific agonist also stimulated Ba2+-sensitive basolateral membrane-dependent facilitation of transcellular ISC-cAMP. PMA did not elicit a similar phenomenon. Prolonged exposure to high-dose PMA but not DOPPA led to apical membrane ISC-cAMP recovery. Changes in PKC alpha-, beta1-, gamma-, and epsilon-isoform membrane partitioning and expression correlated with these findings. PMA-induced transcellular ISC correlated with PKC-alpha membrane association, whereas low doses of both agents inhibited transcellular and apical membrane ISC-cAMP, increased PKC-beta1, decreased PKC-beta2 membrane association, and caused reciprocal changes in isoform mass. During the apical membrane ISC-cAMP recovery after prolonged high-dose PMA exposure, an almost-complete depletion of cellular PKC-beta1 and a significant reduction in PKC-epsilon mass occurred. Thus activated PKC-beta1 and/or PKC-epsilon prevented, whereas activated PKC-alpha facilitated, apical membrane ISC-cAMP. PKC-beta-dependent augmentation of transcellular ISC-cAMP at the level of the basolateral membrane demonstrated that transport events with geographically distinct subcellular membranes can be independently regulated by the PKC beta-isoform.
Collapse
Affiliation(s)
- James R Broughman
- Department of Integrative Biology, University of Texas Health Science Center, Houston, TX 77030, USA
| | | | | | | | | | | |
Collapse
|
41
|
Broughman JR, Sun L, Umar S, Sellin JH, Morris AP. Chronic PKC-beta2 activation in HT-29 Cl.19a colonocytes prevents cAMP-mediated ion secretion by inhibiting apical membrane CFTR targeting. Am J Physiol Gastrointest Liver Physiol 2006; 291:G331-44. [PMID: 16574992 DOI: 10.1152/ajpgi.00356.2005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We investigated the effects of chronically applied PKC-stimulating phorbol esters on subcellular CFTR expression and localization in polarized HT-29 Cl.19A monolayers. Modulation of PKC activity with the PKC-beta-specific agonist 12-deoxyphorbol 13-phenylacetate 20-acetate (DOPPA) or nonisoform-selective PMA altered monolayer CFTR immunofluorescence. A decrease in the CFTR signal within the luminal cellular pole was noted with both phorbol esters. Volumetric analysis of the intracellular CFTR signal revealed that both compounds promoted CFTR accumulation into punctate vesicle-like structures found adjacent to the cellular tight junction [labeled with zona occludens (ZO)-1 antibody], extending basally (DOPPA) into the cell. Puncta were more frequent with DOPPA and larger in size with PMA. DOPPA also promoted ZO-1 accumulation at tricellular corners associated with enhanced CFTR puncta number. The observed loss of CFTR immunofluorescence signal induced by low-dose PMA was related to CFTR sequestration into fewer cytoplasmic puncta and correlated with larger increases in PKC substrate phosphorylation. Both phorbol esters downregulated steady-state cellular CFTR mRNA levels by 70%. However, the effects of DOPPA and PMA were largely independent of CFTR biosynthesis: expression levels were 80-85% of control, and the glycosylation status of immunoprecipitated protein remained largely unchanged. Thus changes in cellular CFTR localization correlated with our companion study showing that PMA-induced inhibition of transcellular cAMP-dependent short-circuit current (ISC) was accompanied by cytoplasmic PKC-beta2 accumulation and modest activation of PKC-beta1 and PKC-epsilon. The inhibitory effect of DOPPA on ISC was related solely to increased cytoplasmic PKC-beta2 levels. Thus PKC-beta2 is hypothesized to participate in the regulation of CFTR apical plasma membrane targeting within the constitutive cellular biosynthetic pathway.
Collapse
Affiliation(s)
- James R Broughman
- Department of Integrative Biology, University of Texas Health Science Center, Houston, TX 77030, USA
| | | | | | | | | |
Collapse
|
42
|
Yamagata T, Yamagata Y, Massé C, Tessier MC, Brochiero E, Dagenais A, Berthiaume Y. Modulation of Na+ transport and epithelial sodium channel expression by protein kinase C in rat alveolar epithelial cells. Can J Physiol Pharmacol 2006; 83:977-87. [PMID: 16391706 DOI: 10.1139/y05-071] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Although the amiloride-sensitive epithelial sodium channel (ENaC) plays an important role in the modulation of alveolar liquid clearance, the precise mechanism of its regulation in alveolar epithelial cells is still under investigation. Protein kinase C (PKC) has been shown to alter ENaC expression and activity in renal epithelial cells, but much less is known about its role in alveolar epithelial cells. The objective of this study was to determine whether PKC activation modulates ENaC expression and transepithelial Na+ transport in cultured rat alveolar epithelial cells. Alveolar type II cells were isolated and cultured for 3 to 4 d before they were stimulated with phorbol 12-myristate 13-acetate (PMA 100 nmol/L) for 4 to 24 h. PMA treatment significantly decreased alpha, beta, and gammaENaC expression in a time-dependent manner, whereas an inactive form of phorbol ester had no apparent effect. This inhibitory action was seen with only 5-min exposure to PMA, which suggested that PKC activation was very important for the reduction of alphaENaC expression. The PKC inhibitors bisindolylmaleimide at 2 micromol/L and Gö6976 at 2 micromol/L diminished the PMA-induced suppression of alphaENaC expression, while rottlerin at 1 micromol/L had no effect. PMA elicited a decrease in total and amiloride-sensitive current across alveolar epithelial cell monolayers. This decline in amiloride-sensitive current was not blocked by PKC inhibitors except for a partial inhibition with bisindolylmaleimide. PMA induced a decrease in rubidium uptake, indicating potential Na+-K+-ATPase inhibition. However, since ouabain-sensitive current in apically permeabilized epithelial cells was similar in PMA-treated and control cells, the inhibition was most probably related to reduced Na+ entry at the apical surface of the cells. We conclude that PKC activation modulates ENaC expression and probably ENaC activity in alveolar epithelial cells. Ca2+-dependent PKC is potentially involved in this response.
Collapse
Affiliation(s)
- Toshiyuki Yamagata
- Département de médecine, Centre de recherche, Centre hospitalier de l'Université de Montréal Hôtel-Dieu, Montreal, QC, Canada
| | | | | | | | | | | | | |
Collapse
|
43
|
Bobryshev P, Bagaeva T, Filaretova L. Gastroprotective action of glucocorticoid hormones in rats with desensitization of capsaicin-sensitive sensory neurons. Inflammopharmacology 2006; 13:217-28. [PMID: 16259741 DOI: 10.1163/156856005774423782] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The ability of glucocorticoid hormones to protect gastric mucosa during desensitization of capsaicin-sensitive afferent neurons has been investigated in rats. Functional ablation of the afferent neurons was performed by pre-treatment with neurotoxic doses of capsaicin (100 mg/kg s.c.). After 1 week of recovery, capsaicin-desensitized, as well as control rats were adrenalectomized or sham-operated. Seven days later, indomethacin at an ulcerogenic dose (35 mg/kg s.c.) was given to each group of rats. One half of adrenalectomized capsaicin-pre-treated rats were injected by corticosterone for replacement (4 mg/kg s.c., 15 min before indomethacin). Gastric lesions, plasma corticosterone and blood glucose levels were estimated 4 h after indomethacin administration. Indomethacin caused gastric erosions that were aggravated by adrenalectomy or desensitization of capsaicin-sensitive afferent neurons approximately with the same extension. Combination of adrenalectomy with the sensory desensitization profoundly potentiated the effect of sensory desensitization alone on indomethacin-induced gastric erosions: the mean gastric erosion area was increased approximately 10-fold. Corticosterone replacement completely prevented this profound effect of adrenalectomy. The results suggest a pivotal role of glucocorticoid hormones in the maintenance of gastric mucosal integrity in the case of impaired gastroprotective mechanisms provided by PGs and capsaicin-sensitive sensory neurons.
Collapse
Affiliation(s)
- P Bobryshev
- Laboratory of Experimental Endocrinology, Pavlov Institute of Physiology, Russian Academy of Sciences, nab. Makarova, 6, St. Petersburg 199034, Russia
| | | | | |
Collapse
|
44
|
Angelow S, Zeni P, Höhn B, Galla HJ. Phorbol ester induced short- and long-term permeabilization of the blood–CSF barrier in vitro. Brain Res 2005; 1063:168-79. [PMID: 16271356 DOI: 10.1016/j.brainres.2005.09.058] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Revised: 09/23/2005] [Accepted: 09/27/2005] [Indexed: 11/18/2022]
Abstract
Interconnected by tight junctions, the epithelial cells of the choroid plexus form a barrier separating the cerebrospinal fluid (CSF) from blood. Using an in vitro model based on porcine choroid plexus epithelial cells (PCPEC), we investigated the influence of PKC activating phorbol 12-myristate 13-acetate (PMA) on barrier properties and analyzed mechanisms involved in the regulation of barrier tightness. Applied in concentrations of 5-25 nM, PMA induced a fast and lasting decrease of the transepithelial electrical resistance (TER), which could be blocked by rottlerin, indicating the involvement of PKCdelta in signal transduction. The immediate impairment of barrier integrity was accompanied by dephosphorylation of occludin and formation of actin bundles. Moreover, in the presence of at least 25 nM PMA, changes of cell shape as well as discontinuities of tight junction strands were observed, suggesting the disruption of cell-cell contacts. Exposure to PMA for 1-2 days additionally induced down-regulation of claudin-2 and up-regulation of barrier modulating matrix metalloproteinase (MMP)-9, respectively. The results show that different interconnected mechanisms directly and indirectly targeting at the tight junctions are released by PMA contributing to the short-term and long-term decrease of TER and opening of the blood-CSF barrier in vitro.
Collapse
Affiliation(s)
- Susanne Angelow
- Institut für Biochemie, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Strasse 2, D-48149 Münster, Germany
| | | | | | | |
Collapse
|
45
|
Del Castillo IC, Fedor-Chaiken M, Song JC, Starlinger V, Yoo J, Matlin KS, Matthews JB. Dynamic regulation of Na(+)-K(+)-2Cl(-) cotransporter surface expression by PKC-{epsilon} in Cl(-)--secretory epithelia. Am J Physiol Cell Physiol 2005; 289:C1332-42. [PMID: 16000638 DOI: 10.1152/ajpcell.00580.2004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In secretory epithelia, activation of PKC by phorbol ester and carbachol negatively regulates Cl(-) secretion, the transport event of secretory diarrhea. Previous studies have implicated the basolateral Na(+)-K(+)-2Cl(-) cotransporter (NKCC1) as a target of PKC-dependent inhibition of Cl(-) secretion. In the present study, we examined the regulation of surface expression of NKCC1 in response to the activation of PKC. Treatment of confluent T84 intestinal epithelial cells with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (PMA) reduced the amount of NKCC1 accessible to basolateral surface biotinylation. Loss of cell surface NKCC1 was due to internalization as shown by 1) the resistance of biotinylated NKCC1 to surface biotin stripping after incubation with PMA and 2) indirect immunofluorescent labeling. PMA-induced internalization of NKCC1 is dependent on the epsilon-isoform of PKC as determined on the basis of sensitivity to a panel of PKC inhibitors. The effect of PMA on surface expression of NKCC1 was specific because PMA did not significantly alter the amount of Na(+)-K(+)-ATPase or E-cadherin available for surface biotinylation. After extended PMA exposure (>2 h), NKCC1 became degraded in a proteasome-dependent fashion. Like PMA, carbachol reduced the amount of NKCC1 accessible to basolateral surface biotinylation in a PKC-epsilon-dependent manner. However, long-term exposure to carbachol did not result in degradation of NKCC1; rather, NKCC1 that was internalized after exposure to carbachol was recycled back to the cell membrane. PKC-epsilon-dependent alteration of NKCC1 surface expression represents a novel mechanism for regulating Cl(-) secretion.
Collapse
Affiliation(s)
- Isabel Calvo Del Castillo
- Dept. of Surgery, Univ. of Cincinnati Medical Center, 231 Albert B. Sabin Way, PO Box 670558, Cincinnati, OH 45267-0558, USA
| | | | | | | | | | | | | |
Collapse
|
46
|
Pierre K, Pellerin L. Monocarboxylate transporters in the central nervous system: distribution, regulation and function. J Neurochem 2005; 94:1-14. [PMID: 15953344 DOI: 10.1111/j.1471-4159.2005.03168.x] [Citation(s) in RCA: 472] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Monocarboxylate transporters (MCTs) are proton-linked membrane carriers involved in the transport of monocarboxylates such as lactate, pyruvate, as well as ketone bodies. They belong to a larger family of transporters composed of 14 members in mammals based on sequence homologies. MCTs are found in various tissues including the brain where three isoforms, MCT1, MCT2 and MCT4, have been described. Each of these isoforms exhibits a distinct regional and cellular distribution in rodent brain. At the cellular level, MCT1 is expressed by endothelial cells of microvessels, by ependymocytes as well as by astrocytes. MCT4 expression appears to be specific for astrocytes. By contrast, the predominant neuronal monocarboxylate transporter is MCT2. Interestingly, part of MCT2 immunoreactivity is located at postsynaptic sites, suggesting a particular role of monocarboxylates and their transporters in synaptic transmission. In addition to variation in expression during development and upon nutritional modifications, new data indicate that MCT expression is regulated at the translational level by neurotransmitters. Understanding how transport of monocarboxylates is regulated could be of particular importance not only for neuroenergetics but also for areas such as functional brain imaging, regulation of food intake and glucose homeostasis, or for central nervous system disorders such as ischaemia and neurodegenerative diseases.
Collapse
Affiliation(s)
- Karin Pierre
- Département de Physiologie, Université de Lausanne, Switzerland
| | | |
Collapse
|
47
|
Sun MK, Alkon DL. Protein kinase C substrate activators: potential as novel antidepressants. Drug Dev Res 2005. [DOI: 10.1002/ddr.20019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
48
|
Affiliation(s)
- John F Di Mari
- Department of Internal Medicine, University of Texas Medical Branch, Galveston 77555-1064, USA.
| | | | | |
Collapse
|
49
|
Um JW, Matthews JB, Song JC, Mun EC. Role of protein kinase C in intestinal ischemic preconditioning. J Surg Res 2005; 124:289-96. [PMID: 15820260 DOI: 10.1016/j.jss.2004.10.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2004] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Tissue protection by ischemic preconditioning (IPC) has been previously characterized in organs such as the heart and involves at least in part PKC activation. It is not yet clear whether such preconditioning against ischemia/reperfusion (I/R) injury operates in the intestine, and, if so, whether IPC involves protein kinase C (PKC). MATERIALS AND METHODS IPC of the small intestine in male Sprague Dawley rats was induced by 10-min superior mesenteric artery (SMA) clamp followed by 120-min reperfusion. Sham-operated control or IPC rats were then rechallenged with 20-min SMA clamp. Histological injury to jejunal mucosa was assessed by microscopic examination and Parks' injury score (Grade 0-4; 0 = no damage). PKC activity was determined by immunoprecipitation of specific isoforms followed by in vitro kinase assay using mucosal scrapings of the harvested jejunum. Data were expressed as mean +/- SEM and analyzed by one-way ANOVA with multiple comparison tests. RESULTS Ten-minute SMA clamp led to epithelial damage that was fully reversed by 120-min reperfusion. Activity of several PKC isoforms (PKCalpha, -delta, -epsilon) increased after 10-min ischemia. Epithelial injury associated with 20-min SMA clamp was attenuated by prior IPC. The protective effect of IPC on intestinal mucosa was prevented when animals were pretreated with the conventional (c) and novel (n) PKC inhibitor Go6850, but not with Go6976 (selective cPKC inhibitor), rottlerin (selective PKCdelta inhibitor), or saline control. CONCLUSIONS Brief mesenteric ischemia induces a reversible epithelial injury in rats associated with activation of several PKC isoforms. Injury induced by mesenteric ischemia is reduced by brief ischemic preconditioning, an effect that is abolished by nonselective PKC inhibition but not by a selective inhibitor of cPKC or PKCdelta. The results suggest that activation of nPKC isoform(s), especially PKCepsilon during and following ischemic insults (IPC), may play an important role in protection against I/R injury in the intestine.
Collapse
Affiliation(s)
- Jun W Um
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | | | | | | |
Collapse
|
50
|
D'Souza T, Agarwal R, Morin PJ. Phosphorylation of claudin-3 at threonine 192 by cAMP-dependent protein kinase regulates tight junction barrier function in ovarian cancer cells. J Biol Chem 2005; 280:26233-40. [PMID: 15905176 DOI: 10.1074/jbc.m502003200] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Claudins are integral membrane proteins essential in the formation and function of tight junctions (TJs). Disruption of TJs, which have essential roles in cell permeability and polarity, is thought to contribute to epithelial tumorigenesis. Claudin-3 and -4 are frequently overexpressed in ovarian cancer, but the molecular pathways involved in the regulation of these proteins are unclear. Interestingly, several studies have demonstrated a role for phosphorylation in the regulation of TJ complexes, although evidence for claudin phosphorylation is scarce. Here, we showed that claudin-3 and -4 can be phosphorylated in ovarian cancer cells. In vitro phosphorylation assays using glutathione S-transferase fusion constructs demonstrated that the C terminus of claudin-3 is an excellent substrate for cAMP-dependent protein kinase (PKA). Using site-directed mutagenesis, we identified a PKA phosphorylation site at amino acid 192 in the C terminus of claudin-3. Overexpression of the protein containing a T192D mutation, mimicking the phosphorylated state, resulted in a decrease in TJ strength in ovarian cancer cell line OVCA433. Our results suggest that claudin-3 phosphorylation by PKA, a kinase frequently activated in ovarian cancer, may provide a mechanism for the disruption of TJs in this cancer. In addition, our findings may have general implications for the regulation of TJs in normal epithelial cells.
Collapse
Affiliation(s)
- Theresa D'Souza
- Laboratory of Cellular and Molecular Biology, Gerontology Research Center, NIA, National Institutes of Health, Baltimore, Maryland 21224, USA
| | | | | |
Collapse
|