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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.
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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
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Fathima S, Hakeem WGA, Shanmugasundaram R, Selvaraj RK. Necrotic Enteritis in Broiler Chickens: A Review on the Pathogen, Pathogenesis, and Prevention. Microorganisms 2022; 10:microorganisms10101958. [PMID: 36296234 PMCID: PMC9610872 DOI: 10.3390/microorganisms10101958] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 11/06/2022] Open
Abstract
Clostridium perfringens type A and C are the primary etiological agents associated with necrotic enteritis (NE) in poultry. The predisposing factors implicated in the incidence of NE changes the physical properties of the gut, immunological status of birds, and disrupt the gut microbial homeostasis, causing an over-proliferation of C. perfringens. The principal virulence factors contributing to the pathogenesis of NE are the α-toxin, β-toxin, and NetB toxin. The immune response to NE in poultry is mediated by the Th1 pathway or cytotoxic T-lymphocytes. C. perfringens type A and C are also pathogenic in humans, and hence are of public health significance. C. perfringens intoxications are the third most common bacterial foodborne disease after Salmonella and Campylobacter. The restrictions on the use of antibiotics led to an increased incidence of NE in poultry. Hence, it is essential to develop alternative strategies to keep the prevalence of NE under check. The control strategies rely principally on the positive modulation of host immune response, nutritional manipulation, and pathogen reduction. Current knowledge on the etiology, pathogenesis, predisposing factors, immune response, effect on the gut microbial homeostasis, and preventative strategies of NE in this post-antibiotic era is addressed in this review.
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Affiliation(s)
- Shahna Fathima
- Department of Poultry Science, The University of Georgia, Athens, GA 30602, USA
| | | | - Revathi Shanmugasundaram
- Toxicology and Mycotoxin Research Unit, US National Poultry Research Center, Athens, GA 30605, USA
| | - Ramesh K. Selvaraj
- Department of Poultry Science, The University of Georgia, Athens, GA 30602, USA
- Correspondence:
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Du J, Xiang X, Xu D, Cui K, Pang Y, Xu W, Mai K, Ai Q. LPS Stimulation Induces Small Heterodimer Partner Expression Through the AMPK-NRF2 Pathway in Large Yellow Croaker ( Larimichthys crocea). Front Immunol 2021; 12:753681. [PMID: 34819934 PMCID: PMC8607525 DOI: 10.3389/fimmu.2021.753681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/05/2021] [Indexed: 11/13/2022] Open
Abstract
The mall heterodimer partner (SHP) plays an important regulatory role in mammal inflammation. The main objective of this study was to investigate the response of SHP to inflammatory stimulation and its underlying mechanism. The shp gene from large yellow croakers, was cloned, and this gene is mainly expressed in the liver and intestine. Lipopolysaccharide (LPS) stimulation induced the mRNA expression and protein level of SHP in macrophages of large yellow croakers. Overexpression of SHP significantly decreased mRNA expression of tnfα, il-1β, il-6 and cox2 induced by LPS treatment in macrophages. LPS stimulation increased the phosphorylation level of Adenosine 5’-monophosphate (AMP)-activated protein kinase (AMPK) in macrophages. AMPK inhibitor treatment significantly decreased the expression of SHP induced by LPS while AMPK activator significantly increased the expression of SHP. The nuclear factor-erythroid 2-related factor 2 (NRF2) increased the promoter activity of SHP in large yellow croakers and the level of nuclear NRF2 was increased by LPS stimulation and AMPK activation. NRF2 inhibitor treatment significantly decreased mRNA expression of shp induced by LPS and AMPK activator. In conclusion, LPS can induce SHP expression by activating the AMPK-NRF2 pathway while SHP could negatively regulate LPS-induced inflammation in large yellow croakers. This study may be benefit to the development of immunology of marine fish and provide new ideas for inflammation-related diseases.
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Affiliation(s)
- Jianlong Du
- Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture and Rural Affairs) & Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Xiaojun Xiang
- Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture and Rural Affairs) & Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Dan Xu
- Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture and Rural Affairs) & Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Kun Cui
- Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture and Rural Affairs) & Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Yuning Pang
- Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture and Rural Affairs) & Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Wei Xu
- Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture and Rural Affairs) & Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Kangsen Mai
- Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture and Rural Affairs) & Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Qinghui Ai
- Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture and Rural Affairs) & Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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4
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Emami NK, Dalloul RA. Centennial Review: Recent developments in host-pathogen interactions during necrotic enteritis in poultry. Poult Sci 2021; 100:101330. [PMID: 34280643 PMCID: PMC8318987 DOI: 10.1016/j.psj.2021.101330] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/06/2021] [Accepted: 06/08/2021] [Indexed: 02/08/2023] Open
Abstract
Necrotic enteritis (NE) is a significant enteric disease in commercial poultry with considerable economic effect on profitability manifested by an estimated $6 billion in annual losses to the global industry. NE presents a unique challenge, being a complex enteric disease that often leads to either clinical (acute) or subclinical (chronic) form. The latter typically results in poor performance (reduced feed intake, weight gain and eventually higher feed conversion ratio [FCR]) with low mortality rates, and represents the greatest economic impact on poultry production. The use of antibiotic growth promoters (AGPs) has been an effective tool in protecting birds from enteric diseases by maintaining enteric health and modifying gut microbiota, thus improving broilers’ production efficiency and overall health. The removal of AGPs presented the poultry industry with several challenges, including reduced bird health and immunity as well as questioning the safety of poultry products. Consequently, research on antibiotic alternatives that can support gut health was intensified. Probiotics, prebiotics, essential oils, and organic acids were among various additives that have been tested for their efficacy against NE with some being effective but not to the level of AGPs. The focus of this review is on the relationship between NE pathogenesis, microbiome, and host immune responses, along with references to recent reviews addressing production aspects of NE. With a comprehensive understanding of these dynamic changes, new and programmed strategies could be developed to make use of the current products more effectively or build a stepping stone toward the development of a new generation of supplements.
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Affiliation(s)
- Nima K Emami
- Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Rami A Dalloul
- Department of Poultry Science, University of Georgia, Athens, GA 30602, USA.
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Emami NK, Calik A, White MB, Young M, Dalloul RA. Necrotic Enteritis in Broiler Chickens: The Role of Tight Junctions and Mucosal Immune Responses in Alleviating the Effect of the Disease. Microorganisms 2019; 7:E231. [PMID: 31370350 PMCID: PMC6723922 DOI: 10.3390/microorganisms7080231] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/25/2019] [Accepted: 07/29/2019] [Indexed: 12/14/2022] Open
Abstract
Necrotic enteritis (NE) continues to present major challenges to the poultry industry, and the etiologic agent Clostridium perfringens is the fourth leading cause of bacterially-induced food- borne illnesses in the US. This study was designed to evaluate the effects of a probiotic during naturally occurring NE. On day of hatch, 1080 Cobb 500 male broilers were randomly allocated to three groups (12 replicate pens/treatment, 30 birds/pen) including 1) negative control (NC): corn-soybean meal diet; 2) positive control (PC): NC + 20 mg virginiamycin/kg diet (0.450 kg Stafac®20/ton); and 3) NC + PrimaLac (1.36 and 0.91 kg/ton from 1-21 and 22-42 days, respectively). One day (d) post placement, all birds were challenged by a commercial live oocyst coccidia vaccine as a predisposing factor to NE. Body weight and feed intake were measured at the onset of NE (d 8) and end of each feeding phase. On d 8, small intestines of two birds/pen were examined for NE lesions, and jejunum samples from one bird were collected for mRNA gene expression analysis of tight junction proteins, cytokines, and nutrient transporters. Data were analyzed using the Jump (JMP) software and significance between treatments identified by LSD (P < 0.05). Compared to NC, supplementation of probiotic reduced d 1-42 mortality; however, PC was the only group with significantly lower mortality. Despite significantly improved feed conversion ratio (FCR) in PC and probiotic groups during d 1-42, average daily gain was only higher in PC (77.69 g/bird) compared with NC (74.99 g/bird). Furthermore, probiotic and PC groups had significantly reduced lesion scores in the duodenum and jejunum compared to NC. Expression of claudin-3 was higher, while expression of zonula occluden-2 tended (P = 0.06) to be higher in probiotic-supplemented birds compared to NC. Moreover, birds fed the probiotic diet had significantly higher expression of IL-10, IL-17, AMPK-α1, and SGLT1 mRNA compared to NC birds. The expression of PepT1 was higher for the probiotic-supplemented group compared to PC. IFN-γ expression was lower in PC compared to NC, while there was no difference between probiotic and NC. There were no differences in gene expression of sIgA, TNF-α, IL-1β, and IL-22 among treatments. Collectively, these data indicate that in a naturally occurring NE model, supplementation of a probiotic helps to improve FCR and reduce lesions, potentially due to the improvements in mRNA expression of tight junctions, cytokines, and nutrient transporters.
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Affiliation(s)
- Nima K Emami
- Avian Immunobiology Laboratory, Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Ali Calik
- Avian Immunobiology Laboratory, Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Animal Nutrition and Nutritional Diseases, Faculty of Veterinary Medicine, Ankara University, Ankara 06110, Turkey
| | - Mallory B White
- Avian Immunobiology Laboratory, Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Mark Young
- Star-Labs/Forage Research, Inc., Clarksdale, 64430 MO, USA
| | - Rami A Dalloul
- Avian Immunobiology Laboratory, Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
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Zhu MJ, Sun X, Du M. AMPK in regulation of apical junctions and barrier function of intestinal epithelium. Tissue Barriers 2018; 6:1-13. [PMID: 30130441 DOI: 10.1080/21688370.2018.1487249] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Gut epithelium covers the inner layer of the gastrointestinal tract and provides a physical barrier to separate the host from its external environment, and its barrier function is critical for maintaining host health. AMP-activated protein kinase (AMPK) as a master regulator of energy metabolism plays a critical role in epithelial barrier function. AMPK activation promotes epithelial differentiation and facilitates cell polarity establishment, both of which strengthen epithelial barrier. In addition, AMPK promotes the assembly of tight junctions and adherens junctions by direct phosphorylation of proteins composing apical junctions, junctional anchors, and cytoskeletons. Pharmacological and nutraceutical compounds, as well as physiological states triggering AMPK activation strengthen epithelial barrier function. This review summarized recent progress in delineating the regulatory roles of AMPK in apical junction formation and barrier function of intestinal epithelium.
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Affiliation(s)
- Mei-Jun Zhu
- a School of Food Science , Washington State University , Pullman , WA, USA
| | - Xiaofei Sun
- a School of Food Science , Washington State University , Pullman , WA, USA
| | - Min Du
- b Department of Animal Sciences , Washington State University , Pullman , WA, USA
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7
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Rowart P, Wu J, Caplan MJ, Jouret F. Implications of AMPK in the Formation of Epithelial Tight Junctions. Int J Mol Sci 2018; 19:E2040. [PMID: 30011834 PMCID: PMC6073107 DOI: 10.3390/ijms19072040] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/09/2018] [Accepted: 07/09/2018] [Indexed: 01/13/2023] Open
Abstract
Tight junctions (TJ) play an essential role in the epithelial barrier. By definition, TJ are located at the demarcation between the apical and baso-lateral domains of the plasma membrane in epithelial cells. TJ fulfill two major roles: (i) TJ prevent the mixing of membrane components; and (ii) TJ regulate the selective paracellular permeability. Disruption of TJ is regarded as one of the earliest hallmarks of epithelial injury, leading to the loss of cell polarity and tissue disorganization. Many factors have been identified as modulators of TJ assembly/disassembly. More specifically, in addition to its role as an energy sensor, adenosine monophosphate-activated protein kinase (AMPK) participates in TJ regulation. AMPK is a ubiquitous serine/threonine kinase composed of a catalytic α-subunit complexed with regulatory β-and γ-subunits. AMPK activation promotes the early stages of epithelial TJ assembly. AMPK phosphorylates the adherens junction protein afadin and regulates its interaction with the TJ-associated protein zonula occludens (ZO)-1, thereby facilitating ZO-1 distribution to the plasma membrane. In the present review, we detail the signaling pathways up-and down-stream of AMPK activation at the time of Ca2+-induced TJ assembly.
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Affiliation(s)
- Pascal Rowart
- Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA), Cardiovascular Sciences, University of Liège (ULiège), Avenue de L'Hôpital 11, 4000 Liège, Belgium.
| | - Jingshing Wu
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06520, USA.
| | - Michael J Caplan
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06520, USA.
| | - François Jouret
- Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA), Cardiovascular Sciences, University of Liège (ULiège), Avenue de L'Hôpital 11, 4000 Liège, Belgium.
- Division of Nephrology, Centre Hospitalier Universitaire de Liège (CHU of Liège), University of Liège (CHU ULiège), 13-B4000 Liège, Belgium.
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Yamada E, Okada S, Bastie CC, Vatish M, Nakajima Y, Shibusawa R, Ozawa A, Pessin JE, Yamada M. Fyn phosphorylates AMPK to inhibit AMPK activity and AMP-dependent activation of autophagy. Oncotarget 2018; 7:74612-74629. [PMID: 27626315 PMCID: PMC5340180 DOI: 10.18632/oncotarget.11916] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 09/05/2016] [Indexed: 02/06/2023] Open
Abstract
We previously demonstrated that proto-oncogene Fyn decreased energy expenditure and increased metabolic phenotypes. Also Fyn decreased autophagy-mediated muscle mass by directly inhibiting LKB1 and stimulating STAT3 activities, respectively. AMPK, a downstream target of LKB1, was recently identified as a key molecule controlling autophagy. Here we identified that Fyn phosphorylates the α subunit of AMPK on Y436 and inhibits AMPK enzymatic activity without altering the assembly state of the AMPK heterotrimeric complex. As pro-inflammatory mediators are reported modulators of the autophagy processes, treatment with the pro-inflammatory cytokine TNFα resulted in 1) increased Fyn activity 2) stimulated Fyn-dependent AMPKα tyrosine phosphorylation and 3) decreased AICAR-dependent AMPK activation. Importantly, TNFα induced inhibition of autophagy was not observed when AMPKα was mutated on Y436. 4) These data demonstrate that Fyn plays an important role in relaying the effects of TNFα on autophagy and apoptosis via phosphorylation and inhibition of AMPK.
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Affiliation(s)
- Eijiro Yamada
- Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Shuichi Okada
- Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Claire C Bastie
- Division of Biomedical Sciences, Warwick Medical School, Coventry, West Midlands, United Kingdom
| | - Manu Vatish
- Nuffield Department of Obstetrics & Gynaecology, University of Oxford, Oxford, United Kingdom
| | - Yasuyo Nakajima
- Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Ryo Shibusawa
- Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Atsushi Ozawa
- Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Jeffrey E Pessin
- Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Masanobu Yamada
- Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Japan
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The stress polarity pathway: AMPK 'GIV'-es protection against metabolic insults. Aging (Albany NY) 2017; 9:303-314. [PMID: 28209925 PMCID: PMC5361665 DOI: 10.18632/aging.101179] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 02/09/2017] [Indexed: 12/17/2022]
Abstract
Loss of cell polarity impairs organ development and function; it can also serve as one of the first triggers for oncogenesis. In 2006-2007 two groups simultaneously reported the existence of a special pathway for maintaining epithelial polarity in the face of environmental stressors. In this pathway, AMPK, a key sensor of metabolic stress stabilizes tight junctions, preserves cell polarity, and thereby, maintains epithelial barrier functions. Accumulating evidence since has shown that pharmacologic activation of AMPK by Metformin protects the epithelial barrier against multiple environmental and pathological stressful states and suppresses tumorigenesis. How AMPK protects the epithelium remained unknown until recently Aznar et al. identified GIV/Girdin as a novel effector of AMPK at the cell-cell junctions; phosphorylation of GIV at a single site by AMPK appears to be both necessary and sufficient for strengthening tight junctions and preserving cell polarity and epithelial barrier function in the face of energetic stress. Here we review the fundamentals of this specialized signaling pathway that buttresses cell-cell junctions against stress-induced collapse and discuss its pathophysiologic relevance in the context of a variety of diseases, including cancers, diabetes, aging, and the growing list of beneficial effects of the AMPK-activator, Metformin.
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Mesenchymal Stromal Cells Accelerate Epithelial Tight Junction Assembly via the AMP-Activated Protein Kinase Pathway, Independently of Liver Kinase B1. Stem Cells Int 2017; 2017:9717353. [PMID: 28781597 PMCID: PMC5525096 DOI: 10.1155/2017/9717353] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/21/2017] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Mesenchymal stromal cells (MSC) are fibroblast-like multipotent cells capable of tissue-repair properties. Given the essentiality of tight junctions (TJ) in epithelial integrity, we hypothesized that MSC modulate TJ formation, via the AMP-activated kinase (AMPK) pathway. Liver kinase-β1 (LKB1) and Ca2+-calmodulin-dependent protein kinase kinase (CaMKK) represent the main kinases that activate AMPK. METHODS The in vitro Ca2+ switch from 5 μM to 1.8 mM was performed using epithelial Madin-Darby canine kidney (MDCK) cells cultured alone or cocultured with rat bone marrow-derived MSC or preexposed to MSC-conditioned medium. TJ assembly was measured by assessing ZO-1 relocation to cell-cell contacts. Experiments were conducted using MDCK stably expressing short-hairpin-RNA (shRNA) against LKB1 or luciferase (LUC, as controls). Compound STO-609 (50 μM) was used as CaMKK inhibitor. RESULTS Following Ca2+ switch, ZO-1 relocation and phosphorylation/activation of AMPK were significantly higher in MDCK/MSC compared to MDCK. No difference in AMPK phosphorylation was observed between LKB1-shRNA and Luc-shRNA MDCK following Ca2+ switch. Conversely, incubation with STO-609 prior to Ca2+ switch prevented AMPK phosphorylation and ZO-1 relocation. MSC-conditioned medium slightly but significantly increased AMPK activation and accelerated TJ-associated distribution of ZO-1 post Ca2+ switch in comparison to regular medium. CONCLUSIONS MSC modulate the assembly of epithelial TJ, via the CaMKK/AMPK pathway independently of LKB1.
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Nighot P, Ma T. Role of autophagy in the regulation of epithelial cell junctions. Tissue Barriers 2016; 4:e1171284. [PMID: 27583189 DOI: 10.1080/21688370.2016.1171284] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 01/07/2023] Open
Abstract
Autophagy is a cell survival mechanism by which bulk cytoplasmic material, including soluble macromolecules and organelles, is targeted for lysosomal degradation. The role of autophagy in diverse cellular processes such as metabolic stress, neurodegeneration, cancer, aging, immunity, and inflammatory diseases is being increasingly recognized. Epithelial cell junctions play an integral role in the cell homeostasis via physical binding, regulating paracellular pathways, integrating extracellular cues into intracellular signaling, and cell-cell communication. Recent data indicates that cell junction composition is very dynamic. The junctional protein complexes are actively regulated in response to various intra- and extra-cellular clues by intracellular trafficking and degradation pathways. This review discusses the recent and emerging information on how autophagy regulates various epithelial cell junctions. The knowledge of autophagy regulation of epithelial junctions will provide further rationale for targeting autophagy in a wide variety of human disease conditions.
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Affiliation(s)
- Prashant Nighot
- Department of Internal Medicine, University of New Mexico School of Medicine , Albuquerque, NM, USA
| | - Thomas Ma
- Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, USA; Veterans Affairs Medical Center, Albuquerque, NM, USA
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12
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Xiang RL, Mei M, Cong X, Li J, Zhang Y, Ding C, Wu LL, Yu GY. Claudin-4 is required for AMPK-modulated paracellular permeability in submandibular gland cells. J Mol Cell Biol 2014; 6:486-97. [PMID: 25503106 DOI: 10.1093/jmcb/mju048] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Tight junction plays an important role in mediating paracellular permeability in epithelia. We previously found that activation of AMP-activated protein kinase (AMPK) increased saliva secretion by modulating paracellular permeability in submandibular glands. However, the molecular mechanisms underlying AMPK-modulated paracellular permeability are unknown. In this study, we found that AICAR, an AMPK agonist, increased saliva secretion in the isolated rat submandibular glands, decreased transepithelial electrical resistance (TER), and increased 4 kDa FITC-dextran flux in cultured SMG-C6 cells. AICAR also induced redistribution of tight junction protein claudin-4, but not claudin-1, claudin-3, occludin, or ZO-1, from the cytoplasm to the membrane. Moreover, knockdown of claudin-4 by shRNA suppressed while claudin-4 re-expression restored the TER and 4 kDa FITC-dextran flux responses to AICAR. Additionally, AICAR increased ERK1/2 phosphorylation, and inhibition of ERK1/2 by U0126, an ERK1/2 kinase inhibitor, or by siRNA decreased AICAR-induced TER responses. AICAR induced the serine S199 phosphorylation of claudin-4 and enhanced the interaction of claudin-4 and occludin. Furthermore, pretreatment with U0126 significantly suppressed AMPK-modulated phosphorylation, redistribution, and interaction with occludin of claudin-4. Taken together, these results indicated that claudin-4 played a crucial role in AMPK-modulated paracellular permeability and ERK1/2 was required in AMPK-modulated tight junction barrier function in submandibular gland.
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Affiliation(s)
- Ruo-Lan Xiang
- Center for Salivary Gland Diseases of Peking University School and Hospital of Stomatology, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100191, China
| | - Mei Mei
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing 100081, China
| | - Xin Cong
- Center for Salivary Gland Diseases of Peking University School and Hospital of Stomatology, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100191, China
| | - Jing Li
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing 100081, China
| | - Yan Zhang
- Center for Salivary Gland Diseases of Peking University School and Hospital of Stomatology, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100191, China
| | - Chong Ding
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing 100081, China
| | - Li-Ling Wu
- Center for Salivary Gland Diseases of Peking University School and Hospital of Stomatology, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100191, China
| | - Guang-Yan Yu
- Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing 100081, China
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Soares H, Marinho HS, Real C, Antunes F. Cellular polarity in aging: role of redox regulation and nutrition. GENES AND NUTRITION 2013; 9:371. [PMID: 24306961 DOI: 10.1007/s12263-013-0371-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 11/19/2013] [Indexed: 02/06/2023]
Abstract
Cellular polarity concerns the spatial asymmetric organization of cellular components and structures. Such organization is important not only for biological behavior at the individual cell level, but also for the 3D organization of tissues and organs in living organisms. Processes like cell migration and motility, asymmetric inheritance, and spatial organization of daughter cells in tissues are all dependent of cell polarity. Many of these processes are compromised during aging and cellular senescence. For example, permeability epithelium barriers are leakier during aging; elderly people have impaired vascular function and increased frequency of cancer, and asymmetrical inheritance is compromised in senescent cells, including stem cells. Here, we review the cellular regulation of polarity, as well as the signaling mechanisms and respective redox regulation of the pathways involved in defining cellular polarity. Emphasis will be put on the role of cytoskeleton and the AMP-activated protein kinase pathway. We also discuss how nutrients can affect polarity-dependent processes, both by direct exposure of the gastrointestinal epithelium to nutrients and by indirect effects elicited by the metabolism of nutrients, such as activation of antioxidant response and phase-II detoxification enzymes through the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2). In summary, cellular polarity emerges as a key process whose redox deregulation is hypothesized to have a central role in aging and cellular senescence.
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Affiliation(s)
- Helena Soares
- Departamento de Química e Bioquímica, Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
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14
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Role of AMP-activated protein kinase in adipose tissue metabolism and inflammation. Clin Sci (Lond) 2013; 124:491-507. [PMID: 23298225 DOI: 10.1042/cs20120536] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
AMPK (AMP-activated protein kinase) is a key regulator of cellular and whole-body energy balance. AMPK phosphorylates and regulates many proteins concerned with nutrient metabolism, largely acting to suppress anabolic ATP-consuming pathways while stimulating catabolic ATP-generating pathways. This has led to considerable interest in AMPK as a therapeutic target for the metabolic dysfunction observed in obesity and insulin resistance. The role of AMPK in skeletal muscle and the liver has been extensively studied, such that AMPK has been demonstrated to inhibit synthesis of fatty acids, cholesterol and isoprenoids, hepatic gluconeogenesis and translation while increasing fatty acid oxidation, muscle glucose transport, mitochondrial biogenesis and caloric intake. The role of AMPK in the other principal metabolic and insulin-sensitive tissue, adipose, remains poorly characterized in comparison, yet increasing evidence supports an important role for AMPK in adipose tissue function. Obesity is characterized by hypertrophy of adipocytes and the development of a chronic sub-clinical pro-inflammatory environment in adipose tissue, leading to increased infiltration of immune cells. This combination of dysfunctional hypertrophic adipocytes and a pro-inflammatory environment contributes to insulin resistance and the development of Type 2 diabetes. Exciting recent studies indicate that AMPK may not only influence metabolism in adipocytes, but also act to suppress this pro-inflammatory environment, such that targeting AMPK in adipose tissue may be desirable to normalize adipose dysfunction and inflammation. In the present review, we discuss the role of AMPK in adipose tissue, focussing on the regulation of carbohydrate and lipid metabolism, adipogenesis and pro-inflammatory pathways in physiological and pathophysiological conditions.
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15
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Tang XX, Fok KL, Chen H, Chan KS, Tsang LL, Rowlands DK, Zhang XH, Da Dong J, Ruan YC, Jiang X, Yu SSB, Chung YW, Chan HC. Lymphocyte CFTR promotes epithelial bicarbonate secretion for bacterial killing. J Cell Physiol 2012; 227:3887-94. [DOI: 10.1002/jcp.24101] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Salt IP, Palmer TM. Exploiting the anti-inflammatory effects of AMP-activated protein kinase activation. Expert Opin Investig Drugs 2012; 21:1155-67. [DOI: 10.1517/13543784.2012.696609] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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17
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Abstract
After years of extensive scientific discovery much has been learned about the networks that regulate epithelial homeostasis. Loss of expression or functional activity of cell adhesion and cell polarity proteins (including the PAR, crumbs (CRB) and scribble (SCRIB) complexes) is intricately related to advanced stages of tumour progression and invasiveness. But the key roles of these proteins in crosstalk with the Hippo and liver kinase B1 (LKB1)-AMPK pathways and in epithelial function and proliferation indicate that they may also be associated with the early stages of tumorigenesis. For example, deregulation of adhesion and polarity proteins can cause misoriented cell divisions and increased self-renewal of adult epithelial stem cells. In this Review, we highlight some advances in the understanding of how loss of epithelial cell polarity contributes to tumorigenesis.
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Affiliation(s)
- Fernando Martin-Belmonte
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Madrid 28049, Spain.
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18
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Mirouse V, Billaud M. The LKB1/AMPK polarity pathway. FEBS Lett 2010; 585:981-5. [PMID: 21185289 DOI: 10.1016/j.febslet.2010.12.025] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 12/15/2010] [Accepted: 12/16/2010] [Indexed: 12/26/2022]
Abstract
The LKB1 tumor suppressor kinase is an activator of the AMP-activated protein kinase (AMPK), a metabolic gauge that responds to variations of cellular energetic levels by favoring catabolic versus anabolic processes. Recent studies have provided substantial evidence that LKB1 and AMPK control cell polarity from invertebrates to mammals. This review examines how the LKB1-AMPK pathway, in conjunction with other positional signals, converts energy-sensing information into the activation of Myosin II to maintain epithelial-cell architecture but also to complete cell division. This molecular link between polarity and metabolism may constitute an ancient stress-response protective mechanism that was co-opted for tumor suppression during evolution.
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Affiliation(s)
- Vincent Mirouse
- GReD Laboratory, CNRS UMR 6247, INSERM U931, Clermont Université, Faculté de Médecine, 63000 Clermont-Ferrand, France.
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