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So YJ, Park OJ, Kwon Y, Im J, Lee D, Yun SH, Cho K, Yun CH, Han SH. Bacillus subtilis Induces Human Beta Defensin-2 Through its Lipoproteins in Human Intestinal Epithelial Cells. Probiotics Antimicrob Proteins 2024:10.1007/s12602-024-10224-4. [PMID: 38376819 DOI: 10.1007/s12602-024-10224-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2024] [Indexed: 02/21/2024]
Abstract
Human intestinal epithelial cells (IECs) play an important role in maintaining gut homeostasis by producing antimicrobial peptides (AMPs). Bacillus subtilis, a commensal bacterium, is considered a probiotic. Although its protective effects on intestinal health are widely reported, the key component of B. subtilis responsible for its beneficial effects remains elusive. In this study, we tried to identify the key molecules responsible for B. subtilis-induced AMPs and their molecular mechanisms in a human IEC line, Caco-2. B. subtilis increased human beta defensin (HBD)-2 mRNA expression in a dose- and time-dependent manner. Among the B. subtilis microbe-associated molecular patterns, lipoprotein (LPP) substantially increased the mRNA expression and protein production of HBD-2, whereas lipoteichoic acid and peptidoglycan did not show such effects. Those results were confirmed in primary human IECs. In addition, both LPP recognition and HBD-2 secretion mainly took place on the apical side of fully differentiated and polarized Caco-2 cells through Toll-like receptor 2-mediated JNK/p38 MAP kinase/AP-1 and NF-κB pathways. HBD-2 efficiently inhibited the growth of the intestinal pathogens Staphylococcus aureus and Bacillus cereus. Furthermore, LPPs pre-incubated with lipase or proteinase K decreased LPP-induced HBD-2 expression, suggesting that the lipid and protein moieties of LPP are crucial for HBD-2 expression. Q Exactive Plus mass spectrometry identified 35 B. subtilis LPP candidates within the LPP preparation, and most of them were ABC transporters. Taken together, these results suggest that B. subtilis promotes HBD-2 secretion in human IECs mainly with its LPPs, which might enhance the protection from intestinal pathogens.
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Affiliation(s)
- Yoon Ju So
- Department of Oral Microbiology and Immunology, and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Ok-Jin Park
- Department of Oral Microbiology and Immunology, and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Yeongkag Kwon
- Department of Oral Microbiology and Immunology, and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jintaek Im
- Department of Oral Microbiology and Immunology, and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dongwook Lee
- Department of Oral Microbiology and Immunology, and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sung-Ho Yun
- Center for Research Equipment, Korea Basic Science Institute, Ochang, 28119, Republic of Korea
| | - Kun Cho
- Center for Research Equipment, Korea Basic Science Institute, Ochang, 28119, Republic of Korea
| | - Cheol-Heui Yun
- Department of Agricultural Biotechnology, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
- Institutes of Green Bio Science & Technology, Seoul National University, Pyeongchang, 25354, Republic of Korea
| | - Seung Hyun Han
- Department of Oral Microbiology and Immunology, and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 08826, Republic of Korea.
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Li J, Han J, Shi Y, Liu M. Rapamycin inhibits corneal inflammatory response and neovascularization in a mouse model of corneal alkali burn. Exp Eye Res 2023:109539. [PMID: 37315833 DOI: 10.1016/j.exer.2023.109539] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 05/26/2023] [Accepted: 06/11/2023] [Indexed: 06/16/2023]
Abstract
Alkali burn-induced corneal injury often causes inflammation and neovascularization and leads to compromised vision. We previously reported that rapamycin ameliorated corneal injury after alkali burns by methylation modification. In this study, we aimed to investigate the rapamycin-medicated mechanism against corneal inflammation and neovascularization. Our data showed that alkali burn could induce a range of different inflammatory response, including a stark upregulation of pro-inflammatory factor expression and an increase in the infiltration of myeloperoxidase- and F4/80-positive cells from the corneal limbus to the central stroma. Rapamycin effectively downregulated the mRNA expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), toll-like receptor 4 (TLR4), nucleotide binding oligomerization domain-like receptors (NLR) family pyrin domain-containing 3 (NLRP3), and Caspase-1, and suppressed the infiltration of neutrophils and macrophages. Inflammation-related angiogenesis mediated by matrix metalloproteinase-2 (MMP-2) and rapamycin restrained this process by inhibiting the TNF-α upregulation in burned corneas of mice. Rapamycin also restrained corneal alkali burn-induced inflammation by regulating HIF-1α/VEGF-mediated angiogenesis and the serum cytokines TNF-α, IL-6, Interferon-gamma (IFN-γ) and granulocyte-macrophage colony-stimulating factor (GM-CSF). The findings of this study indicated rapamycin may reduce inflammation-associated infiltration of inflammatory cells, shape the expression of cytokines, and balance the regulation of MMP-2 and HIF-1α-mediated inflammation and angiogenesis by suppressing mTOR activation in corneal wound healing induced by an alkali injury. It offered novel insights relevant for a potent drug for treating corneal alkali burn.
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Affiliation(s)
- Jiande Li
- College of Life Sciences, Northwest Normal University, Lanzhou, 730070, Gansu, China.
| | - Jiangyuan Han
- College of Life Sciences and Technology, Gansu Agricultural University, Lanzhou, 730070, Gansu, China.
| | - Yongpeng Shi
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China.
| | - Minrui Liu
- College of Life Sciences and Technology, Gansu Agricultural University, Lanzhou, 730070, Gansu, China.
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3
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Fang X, Lian H, Bi S, Liu S, Yuan X, Liao C. Roles of pattern recognition receptors in response to fungal keratitis. Life Sci 2022; 307:120881. [PMID: 35963303 DOI: 10.1016/j.lfs.2022.120881] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/31/2022] [Accepted: 08/08/2022] [Indexed: 11/29/2022]
Abstract
Fungal keratitis is one of the leading causes of blindness worldwide, which has become an increasingly serious threat to public ocular health, but no effective treatment strategies are available now. Pattern recognition receptors (PRRs) of the innate immune system are the first line of host defense against fungal infections. They could recognize pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs) and trigger an array of inflammatory responses. Over the last decades, research has resulted in significant progress regarding the roles of PRRs in fungal keratitis. This review will highlight the importance of several pattern recognition receptors (C-type lectin-like receptors, Toll-like receptors, and NOD-like receptors) in regulating the innate immunity under fungal keratitis and describe the crosstalk and collaboration in PRRs contributing to disease pathology. Meanwhile, some potential therapy-based PRRs against corneal fungal infections are discussed.
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Affiliation(s)
- Xiaolong Fang
- The School of Medicine, Nankai University, Tianjin 300071, China; Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin 300020, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Huifang Lian
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300020, China; Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin 300020, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Department of Ophthalmology, Baoding First Central Hospital, Baoding, Hebei 071000, China
| | - Shihao Bi
- Neck-Shoulder and Lumbocrural Pain Hospital of Shandong First Medical University, Shandong First Medical University, Shandong Academy of Medical Sciences, Jinan, Shandong 250062, China
| | - Sijin Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xiaoyong Yuan
- The School of Medicine, Nankai University, Tianjin 300071, China; Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300020, China; Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin 300020, China.
| | - Chunyang Liao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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4
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Helmy YA, Kassem II, Rajashekara G. Immuno-modulatory effect of probiotic E. coli Nissle 1917 in polarized human colonic cells against Campylobacter jejuni infection. Gut Microbes 2022; 13:1-16. [PMID: 33382951 PMCID: PMC7781529 DOI: 10.1080/19490976.2020.1857514] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Campylobacter jejuni is among the leading causes of bacterial foodborne illness. Poultry is the major reservoir and source of human campylobacteriosis. Currently, there is no effective and practical method to decrease C. jejuni colonization in chickens or to reduce human infections. Additionally, antibiotic-resistant infections pose a serious public health concern; therefore, antibiotic-alternative approaches are needed to reduce transmission of C. jejuni including resistant bacteria from chickens to humans. Here, we evaluated the effect of E. coli Nissle 1917 (EcN) on innate responses of polarized HT-29 cells and consequently on C. jejuni 81176 infections in HT-29 cells. Pre-treatment of HT-29 cells with EcN for 4 h had a significant effect on the invasion of different C. jejuni strains (2 h post-infection) (P < .05) and no intracellular C. jejuni (24 h post-infection) were recovered. To further understand how EcN mediates its impact on C. jejuni's survival inside the cells, we used Human Antibacterial RT2 ProfilerTM PCR arrays to profile gene expression in HT-29 cells after treatment with EcN with or without C. jejuni 81-176 infection. Our results suggest that pre-treatment of the HT-29 cells with EcN induced the anti-inflammatory cytokines and activated the anti-apoptotic Akt signaling which likely to protect the cells against the proinflammatory and apoptosis responses induced by C. jejuni. EcN also positively affected the expression of genes involved in cellular maintenance, growth, development, and proliferation. Further, EcN modulated the expression of genes involved in protective innate immunity, such as TLRs, ERK1/2, p38 MAPK, Ap1, JNK, IL1B, IL17A, and NF-κB signaling.
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Affiliation(s)
- Yosra A. Helmy
- Food Animal Health Research Program, Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, the Ohio State University, Wooster, Ohio, USA
| | - Issmat I. Kassem
- Food Animal Health Research Program, Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, the Ohio State University, Wooster, Ohio, USA,College of Agricultural and Environmental Sciences, Center for Food Safety, University of Georgia, Griffin, Georgia, USA
| | - Gireesh Rajashekara
- Food Animal Health Research Program, Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, the Ohio State University, Wooster, Ohio, USA,Corresponding author Gireesh Rajashekara Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH44691, USA
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Utilization of Sake lees as Broiler Feedstuff and its Effects on Growth Performance and Intestinal Immunity. J Poult Sci 2022; 59:247-259. [PMID: 35989688 PMCID: PMC9346602 DOI: 10.2141/jpsa.0210087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 01/08/2022] [Indexed: 11/22/2022] Open
Abstract
Increasing food loss and waste (FLW) is a global problem, and efforts are being made to use waste food as potential livestock feed material. The amount of self-supplied feed is lower in Japan than in other countries, and the government recommends FLW use for animal feed. Sake (Japanese rice wine) is a traditional alcoholic beverage. During the sake manufacturing process, large amounts of squeezed solids or “lees” (sake lees) are generated. Sake lees are nutritious and functional, but are prone to spoilage. In this study, we investigated whether sake lees should be mixed with animal feed immediately or after drying. To assess the usefulness of sake lees as a poultry feed ingredient and determine the effect of sake lees on intestinal immunity, we performed a feeding trial with three treatments: a raw sake lees (RSL) diet, dried sake lees (DSL) diet, and control diet. Three-week-old broilers were fed these diets (n=8 per group) for two weeks. We then calculated feed efficiency and performed RT-qPCR to assess the effects of diet on intestinal immunity. The growth performance in the RSL diet group was equivalent to that in the control diet group. The DSL diet became difficult for broilers to eat, resulting in decreased growth performance. In the ileum of RSL-diet broilers, the mRNA expression levels of TGF-β1 and avian β-defensin (AvBD)12 were significantly increased compared to those of control diet broilers (p<0.05), and a significant correlation was observed between the two genes (p<0.05). Our results indicated that sake lees should not be dried and should be mixed immediately with feed, and this sake lees when fed to chicken activates the intestinal immunity. However, sake lees have a lower fat content than corn, and it is thus important to combine sake lees with high-energy feed.
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Keshavarz Alikhani H, Shokoohian B, Rezasoltani S, Hossein-Khannazer N, Yadegar A, Hassan M, Vosough M. Application of Stem Cell-Derived Extracellular Vesicles as an Innovative Theranostics in Microbial Diseases. Front Microbiol 2021; 12:785856. [PMID: 34917064 PMCID: PMC8669997 DOI: 10.3389/fmicb.2021.785856] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 11/11/2021] [Indexed: 12/12/2022] Open
Abstract
Extracellular vesicles (EVs), as nano-/micro-scale vehicles, are membranous particles containing various cargoes including peptides, proteins, different types of RNAs and other nucleic acids, and lipids. These vesicles are produced by all cell types, in which stem cells are a potent source for them. Stem cell-derived EVs could be promising platforms for treatment of infectious diseases and early diagnosis. Infectious diseases are responsible for more than 11 million deaths annually. Highly transmissible nature of some microbes, such as newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), drives researcher's interest to set up different strategies to develop novel therapeutic strategies. Recently, EVs-based diagnostic and therapeutic approaches have been launched and gaining momentum very fast. The efficiency of stem cell-derived EVs on treatment of clinical complications of different viruses and bacteria, such as SARS-CoV-2, hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), Staphylococcus aureus, Escherichia coli has been demonstrated. On the other hand, microbial pathogens are able to incorporate their components into their EVs. The microbe-derived EVs have different physiological and pathological impacts on the other organisms. In this review, we briefly discussed biogenesis and the fate of EVs. Then, EV-based therapy was described and recent developments in understanding the potential application of stem cell-derived EVs on pathogenic microorganisms were recapitulated. Furthermore, the mechanisms by which EVs were exploited to fight against infectious diseases were highlighted. Finally, the deriver challenges in translation of stem cell-derived EVs into the clinical arena were explored.
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Affiliation(s)
- Hani Keshavarz Alikhani
- Department of Regenerative Medicine, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Center for Education, Culture and Research, Tehran, Iran
| | - Bahare Shokoohian
- Department of Regenerative Medicine, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Center for Education, Culture and Research, Tehran, Iran
| | - Sama Rezasoltani
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nikoo Hossein-Khannazer
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abbas Yadegar
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Moustapha Hassan
- Experimental Cancer Medicine, Institution for Laboratory Medicine, Karolinska Institute, Stockholm, Sweden
| | - Massoud Vosough
- Department of Regenerative Medicine, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Academic Center for Education, Culture and Research, Tehran, Iran.,Experimental Cancer Medicine, Institution for Laboratory Medicine, Karolinska Institute, Stockholm, Sweden
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7
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Jadi PK, Sharma P, Bhogapurapu B, Roy S. Alternative Therapeutic Interventions: Antimicrobial Peptides and Small Molecules to Treat Microbial Keratitis. Front Chem 2021; 9:694998. [PMID: 34458234 PMCID: PMC8386189 DOI: 10.3389/fchem.2021.694998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/02/2021] [Indexed: 01/10/2023] Open
Abstract
Microbial keratitis is a leading cause of blindness worldwide and results in unilateral vision loss in an estimated 2 million people per year. Bacteria and fungus are two main etiological agents that cause corneal ulcers. Although antibiotics and antifungals are commonly used to treat corneal infections, a clear trend with increasing resistance to these antimicrobials is emerging at rapid pace. Extensive research has been carried out to determine alternative therapeutic interventions, and antimicrobial peptides (AMPs) are increasingly recognized for their clinical potential in treating infections. Small molecules targeted against virulence factors of the pathogens and natural compounds are also explored to meet the challenges and growing demand for therapeutic agents. Here we review the potential of AMPs, small molecules, and natural compounds as alternative therapeutic interventions for the treatment of corneal infections to combat antimicrobial resistance. Additionally, we have also discussed about the different formats of drug delivery systems for optimal administration of drugs to treat microbial keratitis.
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Affiliation(s)
- Praveen Kumar Jadi
- Prof, Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad, India
| | - Prerana Sharma
- Prof, Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad, India
- Department of Animal Sciences, University of Hyderabad, Hyderabad, India
| | - Bharathi Bhogapurapu
- Prof, Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad, India
| | - Sanhita Roy
- Prof, Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad, India
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8
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Ung L, Chodosh J. Foundational concepts in the biology of bacterial keratitis. Exp Eye Res 2021; 209:108647. [PMID: 34097906 PMCID: PMC8595513 DOI: 10.1016/j.exer.2021.108647] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/28/2021] [Accepted: 05/27/2021] [Indexed: 12/12/2022]
Abstract
Bacterial infections of the cornea, or bacterial keratitis (BK), are notorious for causing rapidly fulminant disease and permanent vision loss, even among treated patients. In the last sixty years, dramatic upward trajectories in the frequency of BK have been observed internationally, driven in large part by the commercialization of hydrogel contact lenses in the late 1960s. Despite this worsening burden of disease, current evidence-based therapies for BK - including broad-spectrum topical antibiotics and, if indicated, topical corticosteroids - fail to salvage vision in a substantial proportion of affected patients. Amid growing concerns of rapidly diminishing antibiotic utility, there has been renewed interest in urgently needed novel treatments that may improve clinical outcomes on an individual and public health level. Bridging the translational gap in the care of BK requires the identification of new therapeutic targets and rational treatment design, but neither of these aims can be achieved without understanding the complex biological processes that determine how bacterial corneal infections arise, progress, and resolve. In this chapter, we synthesize the current wealth of human and animal experimental data that now inform our understanding of basic BK pathophysiology, in context with modern concepts in ocular immunology and microbiology. By identifying the key molecular determinants of clinical disease, we explore how novel treatments can be developed and translated into routine patient care.
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Affiliation(s)
- Lawson Ung
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - James Chodosh
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.
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9
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Mutoji KN, Sun M, Elliott G, Moreno IY, Hughes C, Gesteira TF, Coulson-Thomas VJ. Extracellular Matrix Deposition and Remodeling after Corneal Alkali Burn in Mice. Int J Mol Sci 2021; 22:5708. [PMID: 34071909 PMCID: PMC8199272 DOI: 10.3390/ijms22115708] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 12/13/2022] Open
Abstract
Corneal transparency relies on the precise arrangement and orientation of collagen fibrils, made of mostly Type I and V collagen fibrils and proteoglycans (PGs). PGs are essential for correct collagen fibrillogenesis and maintaining corneal homeostasis. We investigated the spatial and temporal distribution of glycosaminoglycans (GAGs) and PGs after a chemical injury. The chemical composition of chondroitin sulfate (CS)/dermatan sulfate (DS) and heparan sulfate (HS) were characterized in mouse corneas 5 and 14 days after alkali burn (AB), and compared to uninjured corneas. The expression profile and corneal distribution of CS/DSPGs and keratan sulfate (KS) PGs were also analyzed. We found a significant overall increase in CS after AB, with an increase in sulfated forms of CS and a decrease in lesser sulfated forms of CS. Expression of the CSPGs biglycan and versican was increased after AB, while decorin expression was decreased. We also found an increase in KS expression 14 days after AB, with an increase in lumican and mimecan expression, and a decrease in keratocan expression. No significant changes in HS composition were noted after AB. Taken together, our study reveals significant changes in the composition of the extracellular matrix following a corneal chemical injury.
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Affiliation(s)
- Kazadi N. Mutoji
- College of Optometry, University of Houston, Houston, TX 77204, USA; (K.N.M.); (M.S.); (G.E.); (I.Y.M.); (T.F.G.)
| | - Mingxia Sun
- College of Optometry, University of Houston, Houston, TX 77204, USA; (K.N.M.); (M.S.); (G.E.); (I.Y.M.); (T.F.G.)
| | - Garrett Elliott
- College of Optometry, University of Houston, Houston, TX 77204, USA; (K.N.M.); (M.S.); (G.E.); (I.Y.M.); (T.F.G.)
| | - Isabel Y. Moreno
- College of Optometry, University of Houston, Houston, TX 77204, USA; (K.N.M.); (M.S.); (G.E.); (I.Y.M.); (T.F.G.)
| | - Clare Hughes
- School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK;
| | - Tarsis F. Gesteira
- College of Optometry, University of Houston, Houston, TX 77204, USA; (K.N.M.); (M.S.); (G.E.); (I.Y.M.); (T.F.G.)
- Optimvia, Batavia, OH 45103, USA
| | - Vivien J. Coulson-Thomas
- College of Optometry, University of Houston, Houston, TX 77204, USA; (K.N.M.); (M.S.); (G.E.); (I.Y.M.); (T.F.G.)
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10
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Jin X, Tian QZ, Zhang M, Cao GF, Yang YF. Modulation of SBD-1 expression by Saccharomyces cerevisiae cell wall components in ovine ruminal epithelial cells. Res Vet Sci 2020; 129:28-38. [PMID: 31927467 DOI: 10.1016/j.rvsc.2020.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 12/26/2019] [Accepted: 01/02/2020] [Indexed: 11/28/2022]
Abstract
The ovine rumen is an immune interface with the external environment, participating in host defence responses. Ovine ruminal epithelial cells (ORECs) not only have a physical barrier function, but also secrete sheep β-defensin-1 (SBD-1), which plays a key role in innate and adaptive immunity. Prebiotics are potential alternatives to infeed antibiotics. Saccharomyces cerevisiae cell wall (S.c.CW) is rich in prebiotics, which play roles in improving the growth performance of animals and regulating immunity. Here, we investigated whether S.c.CW induces SBD-1 expression in ORECs, as well as the underlying mechanism. The regulatory mechanisms of S.c.CW-induced up-regulation of SBD-1 were determined using quantitative real-time PCR, enzyme-linked immunosorbent assay, and western blotting. S.c.CW significantly increased the expression of Toll-like receptor 2 (TLR2) and nuclear factor-kappa B (NF-κB), but had no effect on TLR4 expression. TLR2, MyD88, and NF-κB inhibition attenuated the induction of SBD-1 expression by S.c.CW. However, TLR4 inhibition only resulted in attenuated SBD-1 mRNA, having no effect on SBD-1 protein expression. Thus, we conclude that S.c.CW can induce SBD-1 expression and that this induction is regulated by the TLR2-MyD88-NF-κB pathway.
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Affiliation(s)
- Xin Jin
- Veterinary Medicine College of Inner Mongolia Agricultural University, Hohhot 010018, People's Republic of China; Animal Science and Veterinary Medicine College of Henan Agricultural University, Zhengzhou 450046, People's Republic of China
| | - Qiao-Zhen Tian
- Veterinary Medicine College of Inner Mongolia Agricultural University, Hohhot 010018, People's Republic of China; Medicine college of Shanxi Datong University, Datong 037009, People's Republic of China
| | - Man Zhang
- Veterinary Medicine College of Inner Mongolia Agricultural University, Hohhot 010018, People's Republic of China; Animal Medicine College of Henan University of Animal Husbandry and Economy, Zhengzhou 450046, People's Republic of China
| | - Gui-Fang Cao
- Veterinary Medicine College of Inner Mongolia Agricultural University, Hohhot 010018, People's Republic of China
| | - Yin-Feng Yang
- Veterinary Medicine College of Inner Mongolia Agricultural University, Hohhot 010018, People's Republic of China.
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11
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Jia Y, Si W, Hong Z, Qu M, Zhu N, Liu S, Li G. Toll-like receptor 2-mediated induction of avian β-defensin 9 by Lactobacillus rhamnosus and its cellular components in chicken intestinal epithelial cells. FOOD AGR IMMUNOL 2019. [DOI: 10.1080/09540105.2019.1593325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Yongjie Jia
- Jiangxi Province Key Laboratory of Animal Nutrition, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
| | - Wei Si
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People’s Republic of China
| | - Zhimin Hong
- Jiangxi Province Key Laboratory of Animal Nutrition, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
| | - Mingren Qu
- Jiangxi Province Key Laboratory of Animal Nutrition, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
| | - Nianhua Zhu
- Jiangxi Province Key Laboratory of Animal Nutrition, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
| | - Siguo Liu
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People’s Republic of China
| | - Guanhong Li
- Jiangxi Province Key Laboratory of Animal Nutrition, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, People’s Republic of China
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Sharma P, Sharma N, Mishra P, Joseph J, Mishra DK, Garg P, Roy S. Differential Expression of Antimicrobial Peptides in Streptococcus pneumoniae Keratitis and STAT3-Dependent Expression of LL-37 by Streptococcus pneumoniae in Human Corneal Epithelial Cells. Pathogens 2019; 8:pathogens8010031. [PMID: 30845777 PMCID: PMC6470555 DOI: 10.3390/pathogens8010031] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/27/2019] [Accepted: 03/01/2019] [Indexed: 12/15/2022] Open
Abstract
Streptococcus pneumoniae is the leading cause of bacterial keratitis in the developing world with a growing trend of acquiring resistance against various antibiotics. In the current study, we determined the expression of different antimicrobial peptides (AMPs) in response to S. pneumoniae in patients, as well as in primary and immortalized human corneal epithelial cells. We further focused on LL-37 and determined its expression in human cornea infected with S. pneumoniae and studied the killing ability of LL-37 against S. pneumoniae. The expression of AMPs was determined by quantitative PCR and the phosphorylation of signaling proteins was evaluated by immunoblot analysis. LL-37 expression was also determined by immunofluorescence and Western blot method and the killing ability of LL-37 against S. pneumoniae was determined by colony-forming units. Differential expression of antimicrobial peptides was observed in patients with S. pneumoniae keratitis. Although S. pneumoniae induced expression of the AMPs in human corneal epithelial cells (HCEC), it did not induce AMP expression in U937, a human monocyte cell line. S. pneumoniae also caused activation of nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB)and mitogen activated protein kinase (MAPK) pathways in corneal epithelial cells. LL-37 was found to be effective against both laboratory and clinical strains of S. pneumoniae. LL-37 induction by S. pneumoniae in human corneal epithelial cells was mediated by signal transducer and activator of transcription 3 (STAT3) activation, and inhibition of STAT3 activation significantly reduced LL-37 expression. Our study determines an extensive profile of AMPs expressed in the human cornea during S. pneumoniae infection, and suggests the potential of LL-37 to be developed as an alternative therapeutic intervention to fight increasing antibiotic resistance among bacteria.
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Affiliation(s)
- Prerana Sharma
- Prof. Brien Holden Eye Research Center, LV Prasad Eye Institute, Hyderabad 500034, India.
- Department of Animal Sciences, University of Hyderabad, Hyderabad 500046, India.
| | - Natalia Sharma
- Prof. Brien Holden Eye Research Center, LV Prasad Eye Institute, Hyderabad 500034, India.
| | - Priyasha Mishra
- Prof. Brien Holden Eye Research Center, LV Prasad Eye Institute, Hyderabad 500034, India.
| | - Joveeta Joseph
- Jhaveri Microbiology Centre, LV Prasad Eye Institute, Hyderabad 500034, India.
| | - Dilip K Mishra
- Pathology Department, LV Prasad Eye Institute, Hyderabad 500034, India.
| | - Prashant Garg
- Tej Kohli Cornea Institute, Hyderabad 500034, India.
| | - Sanhita Roy
- Prof. Brien Holden Eye Research Center, LV Prasad Eye Institute, Hyderabad 500034, India.
- Tej Kohli Cornea Institute, Hyderabad 500034, India.
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13
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Dou X, Han J, Ma Q, Cheng B, Shan A, Gao N, Yang Y. TLR2/4-mediated NF-κB pathway combined with the histone modification regulates β-defensins and interleukins expression by sodium phenyl butyrate in porcine intestinal epithelial cells. Food Nutr Res 2018; 62:1493. [PMID: 30574051 PMCID: PMC6294838 DOI: 10.29219/fnr.v62.1493] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 10/18/2018] [Accepted: 10/18/2018] [Indexed: 12/13/2022] Open
Abstract
Background Host defense peptides (HDPs) possess direct antibacterial, antineoplastic, and immunomodulatory abilities, playing a vital role in innate immunity. Dietary-regulated HDP holds immense potential as a novel pathway for preventing infection. Objective In this study, we examined the regulation mechanism of HDPs (pEP2C, pBD-1, and pBD-3) and cytokines (IL-8 and IL-18) expression by sodium phenylbutyrate (PBA). Design The effects of PBA on HDP induction and the mechanism involved were studied in porcine intestinal epithelial cell lines (IPEC J2). Results In this study, the results showed that HDPs (pEP2C, pBD-1, and pBD-3) and cytokines (IL-8 and IL-18) expression was increased significantly upon stimulation with PBA in IPEC J2 cells. Furthermore, toll-like receptor 2 (TLR2) and TLR4 were required for the PBA-mediated upregulation of the HDPs. This process occurred and further activated the NF-κB pathway via the phosphorylation of p65 and an IκB α synthesis delay. Meanwhile, histone deacetylase (HDAC) inhibition and an increased phosphorylation of histone H3 on serine S10 also occurred in PBA-induced HDP expression independently with TLR2 and TLR4. Furthermore, p38-MAPK suppressed PBA-induced pEP2C, pBD-1 pBD-3, IL-8, and IL-18 expression, but ERK1/2 failed to abolish the regulation of pBD-3, IL-8, and IL-18. Moreover, epidermal growth factor receptor (EGFR) is involved in PBA-mediated HDP regulation. Conclusions We concluded that PBA induced HDP and cytokine increases but did not cause an excessive pro-inflammatory response, which proceeded through the TLR2 and TLR4-NF-κB pathway and histone modification in IPEC J2 cells.
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Affiliation(s)
- Xiujing Dou
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, China
| | - Junlan Han
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, China
| | - Qiuyuan Ma
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, China
| | - Baojing Cheng
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, China
| | - Anshan Shan
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, China
| | - Nan Gao
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, China
| | - Yu Yang
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, China
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14
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Kang BY, Lee SS, Bang MH, Jeon H, Kim H, Chung DK. Water-based extracts of Zizania latifolia inhibit Staphylococcus aureus infection through the induction of human beta-defensin 2 expression in HaCaT cells. J Microbiol 2018; 56:910-916. [PMID: 30484159 DOI: 10.1007/s12275-018-8307-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/17/2018] [Accepted: 08/23/2018] [Indexed: 12/22/2022]
Abstract
Zizania latifolia is a perennial herb belonging to the family Gramineae that has been used as a health food in Asian countries. In this study, we investigated the antimicrobial effect of Z. latifolia, which increased human beta-defensin 2 (hBD2) expression in HaCaT cells. hBD2 expression was further increased in cells treated with Z. latifolia extracts and subsequently infected with Staphylococcus aureus. Inversely, S. aureus infection decreased after treatment. The induction of hBD2 in HaCaT cells was mediated by the Toll-like receptor 2 (TLR2) signaling pathway, including the activation of extracellular signal-regulated kinase (ERK) and activator protein 1 (AP-1). Further study using siRNA revealed that hBD2 played an important role in the inhibition of S. aureus infection in HaCaT cells. Our data suggest that Z. latifolia extracts can be used as an antimicrobial ingredient for skin treatment formulas.
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Affiliation(s)
- Bo Yeon Kang
- Graduate School of Biotechnology and Institute of Life Science and Resources, Kyung Hee University, Yongin, 17104, Republic of Korea
| | - Seung-Su Lee
- Skin Biotechnology Center, Kyung Hee University, Yongin, 17104, Republic of Korea
| | - Myun-Ho Bang
- Skin Biotechnology Center, Kyung Hee University, Yongin, 17104, Republic of Korea
| | - Hyoik Jeon
- Graduate School of Biotechnology and Institute of Life Science and Resources, Kyung Hee University, Yongin, 17104, Republic of Korea
| | - Hangeun Kim
- Skin Biotechnology Center, Kyung Hee University, Yongin, 17104, Republic of Korea.
| | - Dae Kyun Chung
- Graduate School of Biotechnology and Institute of Life Science and Resources, Kyung Hee University, Yongin, 17104, Republic of Korea. .,Skin Biotechnology Center, Kyung Hee University, Yongin, 17104, Republic of Korea.
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15
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O'Callaghan RJ. The Pathogenesis of Staphylococcus aureus Eye Infections. Pathogens 2018; 7:pathogens7010009. [PMID: 29320451 PMCID: PMC5874735 DOI: 10.3390/pathogens7010009] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 01/02/2018] [Accepted: 01/04/2018] [Indexed: 02/07/2023] Open
Abstract
Staphylococcus aureus is a major pathogen of the eye able to infect the tear duct, eyelid, conjunctiva, cornea, anterior and posterior chambers, and the vitreous chamber. Of these infections, those involving the cornea (keratitis) or the inner chambers of the eye (endophthalmitis) are the most threatening because of their potential to cause a loss in visual acuity or even blindness. Each of these ocular sites is protected by the constitutive expression of a variety of antimicrobial factors and these defenses are augmented by a protective host response to the organism. Such infections often involve a predisposing factor that weakens the defenses, such as the use of contact lenses prior to the development of bacterial keratitis or, for endophthalmitis, the trauma caused by cataract surgery or intravitreal injection. The structural carbohydrates of the bacterial surface induce an inflammatory response able to reduce the bacterial load, but contribute to the tissue damage. A variety of bacterial secreted proteins including alpha-toxin, beta-toxin, gamma-toxin, Panton-Valentine leukocidin and other two-component leukocidins mediate tissue damage and contribute to the induction of the inflammatory response. Quantitative animal models of keratitis and endophthalmitis have provided insights into the S. aureus virulence and host factors active in limiting such infections.
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Affiliation(s)
- Richard J O'Callaghan
- Department of Microbiology and Immunology, University of Mississippi Medical Center, 2500 N. State St., Jackson, MS 39216, USA.
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16
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PSMA-targeted polyinosine/polycytosine vector induces prostate tumor regression and invokes an antitumor immune response in mice. Proc Natl Acad Sci U S A 2017; 114:13655-13660. [PMID: 29229829 DOI: 10.1073/pnas.1714587115] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
There is an urgent need for an effective treatment for metastatic prostate cancer (PC). Prostate tumors invariably overexpress prostate surface membrane antigen (PSMA). We designed a nonviral vector, PEI-PEG-DUPA (PPD), comprising polyethylenimine-polyethyleneglycol (PEI-PEG) tethered to the PSMA ligand, 2-[3-(1, 3-dicarboxy propyl)ureido] pentanedioic acid (DUPA), to treat PC. The purpose of PEI is to bind polyinosinic/polycytosinic acid (polyIC) and allow endosomal release, while DUPA targets PC cells. PolyIC activates multiple pathways that lead to tumor cell death and to the activation of bystander effects that harness the immune system against the tumor, attacking nontargeted neighboring tumor cells and reducing the probability of acquired resistance and disease recurrence. Targeting polyIC directly to tumor cells avoids the toxicity associated with systemic delivery. PPD selectively delivered polyIC into PSMA-overexpressing PC cells, inducing apoptosis, cytokine secretion, and the recruitment of human peripheral blood mononuclear cells (PBMCs). PSMA-overexpressing tumors in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice with partially reconstituted immune systems were significantly shrunken following PPD/polyIC treatment, in all cases. Half of the tumors showed complete regression. PPD/polyIC invokes antitumor immunity, but unlike many immunotherapies does not need to be personalized for each patient. The potent antitumor effects of PPD/polyIC should spur its development for clinical use.
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17
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Chan JKL, Yuen D, Too PHM, Sun Y, Willard B, Man D, Tam C. Keratin 6a reorganization for ubiquitin-proteasomal processing is a direct antimicrobial response. J Cell Biol 2017; 217:731-744. [PMID: 29191848 PMCID: PMC5800800 DOI: 10.1083/jcb.201704186] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 10/01/2017] [Accepted: 11/08/2017] [Indexed: 01/09/2023] Open
Abstract
Chan et al. show that epithelial cells respond to bacterial components in the environment by releasing subunits of the keratin 6a (K6a) filament network to the cytosol for degradation by the ubiquitin–proteasome system. This generates antimicrobial peptides from K6a that are important for innate defense of the mucosal surface. Skin and mucosal epithelia deploy antimicrobial peptides (AMPs) to eliminate harmful microbes. We reported that the intermediate filament keratin 6a (K6a) is constitutively processed into antimicrobial fragments in corneal epithelial cells. In this study, we show that K6a network remodeling is a host defense response that directly up-regulates production of keratin-derived AMPs (KAMPs) by the ubiquitin–proteasome system (UPS). Bacterial ligands trigger K6a phosphorylation at S19, S22, S37, and S60, leading to network disassembly. Mutagenic analysis of K6a confirmed that the site-specific phosphorylation augmented its solubility. K6a in the cytosol is ubiquitinated by cullin-RING E3 ligases for subsequent proteasomal processing. Without an appreciable increase in K6a gene expression and proteasome activity, a higher level of cytosolic K6a results in enhanced KAMP production. Although proteasome-mediated proteolysis is known to produce antigenic peptides in adaptive immunity, our findings demonstrate its new role in producing AMPs for innate immune defense. Manipulating K6a phosphorylation or UPS activity may provide opportunities to harness the innate immunity of epithelia against infection.
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Affiliation(s)
- Jonathan K L Chan
- Department of Ophthalmic Research, Cole Eye Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH.,Department of Ophthalmology, Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleveland, OH
| | - Don Yuen
- Department of Ophthalmic Research, Cole Eye Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Priscilla Hiu-Mei Too
- Department of Ophthalmic Research, Cole Eye Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Yan Sun
- Department of Ophthalmic Research, Cole Eye Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Belinda Willard
- Proteomics Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - David Man
- Department of Ophthalmic Research, Cole Eye Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Connie Tam
- Department of Ophthalmic Research, Cole Eye Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, OH .,Department of Ophthalmology, Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleveland, OH
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18
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Mohammed I, Said DG, Dua HS. Human antimicrobial peptides in ocular surface defense. Prog Retin Eye Res 2017; 61:1-22. [DOI: 10.1016/j.preteyeres.2017.03.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/22/2017] [Accepted: 03/27/2017] [Indexed: 01/17/2023]
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19
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Corneal Fibroblasts as Sentinel Cells and Local Immune Modulators in Infectious Keratitis. Int J Mol Sci 2017; 18:ijms18091831. [PMID: 28832498 PMCID: PMC5618480 DOI: 10.3390/ijms18091831] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 08/21/2017] [Accepted: 08/21/2017] [Indexed: 01/13/2023] Open
Abstract
The cornea serves as a barrier to protect the eye against external insults including microbial pathogens and antigens. Bacterial infection of the cornea often results in corneal melting and scarring that can lead to severe visual impairment. Not only live bacteria but also their components such as lipopolysaccharide (LPS) of Gram-negative bacteria contribute to the development of inflammation and subsequent corneal damage in infectious keratitis. We describe the important role played by corneal stromal fibroblasts (activated keratocytes) as sentinel cells, immune modulators, and effector cells in infectious keratitis. Corneal fibroblasts sense bacterial infection through Toll-like receptor (TLR)–mediated detection of a complex of LPS with soluble cluster of differentiation 14 (CD14) and LPS binding protein present in tear fluid. The cells then initiate innate immune responses including the expression of chemokines and adhesion molecules that promote the recruitment of inflammatory cells necessary for elimination of the infecting bacteria. Infiltrated neutrophils are activated by corneal stromal collagen and release mediators that stimulate the production of pro–matrix metalloproteinases by corneal fibroblasts. Elastase produced by Pseudomonas aeruginosa (P. aeruginosa) activates these released metalloproteinases, resulting in the degradation of stromal collagen. The modulation of corneal fibroblast activation and of the interaction of these cells with inflammatory cells and bacteria is thus important to minimize corneal scarring during treatment of infectious keratitis. Pharmacological agents that are able to restrain such activities of corneal fibroblasts without allowing bacterial growth represent a potential novel treatment option for prevention of excessive scarring and tissue destruction in the cornea.
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20
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Guillon A, Brea D, Morello E, Tang A, Jouan Y, Ramphal R, Korkmaz B, Perez-Cruz M, Trottein F, O'Callaghan RJ, Gosset P, Si-Tahar M. Pseudomonas aeruginosa proteolytically alters the interleukin 22-dependent lung mucosal defense. Virulence 2017; 8:810-820. [PMID: 27792459 PMCID: PMC5626239 DOI: 10.1080/21505594.2016.1253658] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/16/2016] [Accepted: 10/21/2016] [Indexed: 12/18/2022] Open
Abstract
The IL-22 signaling pathway is critical for regulating mucosal defense and limiting bacterial dissemination. IL-22 is unusual among interleukins because it does not directly regulate the function of conventional immune cells, but instead targets cells at outer body barriers, such as respiratory epithelial cells. Consequently, IL-22 signaling participates in the maintenance of the lung mucosal barrier by controlling cell proliferation and tissue repair, and enhancing the production of specific chemokines and anti-microbial peptides. Pseudomonas aeruginosa is a major pathogen of ventilator-associated pneumonia and causes considerable lung tissue damage. A feature underlying the pathogenicity of this bacterium is its capacity to persist and develop in the host, particularly in the clinical context of nosocomial lung infections. We aimed to investigate the ability of P. auruginosa to disrupt immune-epithelial cells cross-talk. We found that P. aeruginosa escapes the host mucosal defenses by degrading IL-22, leading to severe inhibition of IL-22-mediated immune responses. We demonstrated in vitro that, protease IV, a type 2 secretion system-dependent serine protease, is responsible for the degradation of IL-22 by P. aeruginosa. Moreover, the major anti-proteases molecules present in the lungs were unable to inhibit protease IV enzymatic activity. In addition, tracheal aspirates of patients infected by P. aeruginosa contain protease IV activity which further results in IL-22 degradation. This so far undescribed cleavage of IL-22 by a bacterial protease is likely to be an immune-evasion strategy that contributes to P. aeruginosa-triggered respiratory infections.
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Affiliation(s)
- Antoine Guillon
- Institut National de la Santé et de la Recherche Médicale, Center d'Etude des Pathologies Respiratoires (CEPR), INSERM UMR 1100, Tours, France
- Université François Rabelais de Tours, Tours, France
- CHRU de Tours, Service de Réanimation Polyvalente, Tours, France
| | - Deborah Brea
- Institut National de la Santé et de la Recherche Médicale, Center d'Etude des Pathologies Respiratoires (CEPR), INSERM UMR 1100, Tours, France
- Université François Rabelais de Tours, Tours, France
| | - Eric Morello
- Institut National de la Santé et de la Recherche Médicale, Center d'Etude des Pathologies Respiratoires (CEPR), INSERM UMR 1100, Tours, France
- Université François Rabelais de Tours, Tours, France
| | - Aihua Tang
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Youenn Jouan
- Institut National de la Santé et de la Recherche Médicale, Center d'Etude des Pathologies Respiratoires (CEPR), INSERM UMR 1100, Tours, France
- Université François Rabelais de Tours, Tours, France
- CHRU de Tours, Service de Réanimation Polyvalente, Tours, France
| | - Reuben Ramphal
- Institut National de la Santé et de la Recherche Médicale, Center d'Etude des Pathologies Respiratoires (CEPR), INSERM UMR 1100, Tours, France
- Université François Rabelais de Tours, Tours, France
| | - Brice Korkmaz
- Institut National de la Santé et de la Recherche Médicale, Center d'Etude des Pathologies Respiratoires (CEPR), INSERM UMR 1100, Tours, France
| | - Magdiel Perez-Cruz
- Institut Pasteur de Lille, Center d'Infection et d'Immunité de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique, UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale, U1019, Lille, France
| | - Francois Trottein
- Institut Pasteur de Lille, Center d'Infection et d'Immunité de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique, UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale, U1019, Lille, France
| | - Richard J. O'Callaghan
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Philippe Gosset
- Institut Pasteur de Lille, Center d'Infection et d'Immunité de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique, UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale, U1019, Lille, France
| | - Mustapha Si-Tahar
- Institut National de la Santé et de la Recherche Médicale, Center d'Etude des Pathologies Respiratoires (CEPR), INSERM UMR 1100, Tours, France
- Université François Rabelais de Tours, Tours, France
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21
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Hou A, Tin MQ, Tong L. Toll-like receptor 2-mediated NF-kappa B pathway activation in ocular surface epithelial cells. EYE AND VISION 2017; 4:17. [PMID: 28706958 PMCID: PMC5506675 DOI: 10.1186/s40662-017-0082-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/27/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND Gram-positive bacteria stimulate Toll-like receptor (TLR) 2 and then activate the pro-inflammatory nuclear factor-kappa B (NF-κB) pathway. As the human ocular surface is heavily colonised by gram-positive cocci bacteria, a balance of activation/repression of NF-κB target genes is essential to avoid uncontrolled infection or autoimmune-related inflammation. It is advantageous to test NF-κB targeting molecules in an ocular surface culture system that allows assessment of temporal NF-κB activation in a longitudinal fashion without destruction of cells. Such initial testing under standardised conditions should reduce the number of molecules that progress to further evaluation in animal models. This study aims to establish an in-vitro cell culture system to assess NF-κB activation in the context of ocular surface cells. METHODS NF-κB activity was evaluated through a secretory alkaline phosphatase reporter assay (SEAP). Immunoblots and immunofluorescence were used to examine IκBα phosphorylation and p65/p50 nuclear localization. Monocyte chemoattractant protein-1 (MCP-1) transcripts were evaluated by real time PCR and protein levels were measured by ELISA. RESULTS NF-κB activity in HCE-T cells treated with TLR2 activator Pam3CSK4 was higher than control cells at both 6 and 24 h. Pam3CSK4-stimulated NF-κB activation was inhibited by IκK inhibitors, Wedelolactone and BMS-345541. In Pam3CSK4 treated cells, active NF-κB subunits p50 and p65 increased in cell nuclear fractions as early as 1.5 h. Although the level of total IκB-α remained constant, phospho-IκB-α increased with treatment over time. In the culture media of Pam3CSK4-stimulated cells, MCP-1 protein level was increased, which was suppressed in the presence of IκK inhibitors. CONCLUSION NF-κB pathway can be activated by the TLR2 ligand and inhibited by IκK inhibitors in the ocular surface cell culture system. This cell culture system may be used to evaluate TLR-related innate defences in ocular surface diseases.
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Affiliation(s)
- Aihua Hou
- Ocular Surface Research Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Min Qi Tin
- Ocular Surface Research Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Louis Tong
- Ocular Surface Research Group, Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore, Singapore.,Singapore National Eye Center, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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22
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Fitschen-Oestern S, Weuster M, Lippross S, Behrendt P, Fuchs S, Pufe T, Tohidnezhad M, Bayer A, Seekamp A, Varoga D, Klüter T. Hepatocytes express the antimicrobial peptide HBD-2 after multiple trauma: an experimental study in human and mice. BMC Musculoskelet Disord 2017; 18:100. [PMID: 28270138 PMCID: PMC5341361 DOI: 10.1186/s12891-017-1458-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 02/21/2017] [Indexed: 11/23/2022] Open
Abstract
Background Human-beta defensins (HBD) belong to the family of acute phase peptides and hold a broad antimicrobial spectrum that includes gram-positive and gram-negative bacteria. HBD are up-regulated after severe injuries but the source of posttraumatic HBD expression has not been focused on before. In the current study we analysed the role of liver tissue in expression of HBD after multiple trauma in human and mice. Methods HBD-2 expression has been detected in plasma samples of 32 multiple trauma patients (ISS > 16) over 14 days after trauma by ELISA. To investigate major sources of HBD-2, its expression and regulation in plasma samples, polymorphonuclear neutrophils (PMN) and human tissue samples of liver and skin were analysed by ELISA. As liver samples of trauma patients are hard to obtain we tried to review findings in an established trauma model. Plasma samples and liver samples of 56 male C57BL/6 N-mice with a thorax trauma and a femur fracture were analysed by ELISA, real-time PCR and immunohistochemistry for murine beta defensin 4 (MBD-4) and compared with the expression of control group without trauma. The induction of HBD-2 expression in cultured hepatocytes (Hep G2) was analysed after incubation with IL-6, supernatant of Staphylococcus aureus (SA) and Lipopolysaccharides (LPS). One possible signalling pathway was tested by blocking toll-like receptor 2 (TLR2) in hepatocytes. Results Compared to healthy control group, plasma of multiple traumatized patients and mice showed significantly higher defensin levels after trauma. Compared to skin cells, which are known for high beta defensin expression, liver tissue showed less HBD-2 expression, but higher HBD-2 expression compared to PMN. Immunhistochemical staining demonstrated upregulated MBD-4 in hepatocytes of traumatised mice. In HepG2 cells HBD-2 expression could be increased by stimulation with IL-6 and SA. Neutralization of HepG2 cells with αTLR2 showed reduced HBD-2 expression after stimulation with SA. Conclusion Plasma samples of multiple traumatized patients showed high expression of HBD-2, which may protect the severely injured patient from overwhelming bacterial infection. Our data support the hypothesis that liver is one possible source for HBD-2 in plasma while posttraumatic inflammatory response.
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Affiliation(s)
- Stefanie Fitschen-Oestern
- Department of Trauma Surgery, University Medical Center of Schleswig-Holstein, Campus Kiel, Arnold-Heller-Strasse 3, 24105, Kiel, Germany
| | - Matthias Weuster
- Department of Trauma Surgery, University Medical Center of Schleswig-Holstein, Campus Kiel, Arnold-Heller-Strasse 3, 24105, Kiel, Germany
| | - Sebastian Lippross
- Department of Trauma Surgery, University Medical Center of Schleswig-Holstein, Campus Kiel, Arnold-Heller-Strasse 3, 24105, Kiel, Germany
| | - Peter Behrendt
- Department of Trauma Surgery, University Medical Center of Schleswig-Holstein, Campus Kiel, Arnold-Heller-Strasse 3, 24105, Kiel, Germany
| | - Sabine Fuchs
- Department of Trauma Surgery, University Medical Center of Schleswig-Holstein, Campus Kiel, Arnold-Heller-Strasse 3, 24105, Kiel, Germany
| | - Thomas Pufe
- Department of Trauma Surgery, University of Aachen, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - Mersedeh Tohidnezhad
- Department of Trauma Surgery, University of Aachen, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - Andreas Bayer
- Department of Cardiovascular Surgery, University Medical Center of Schleswig-Holstein, Campus Kiel, Arnold-Heller-Strasse 3, 24105, Kiel, Germany
| | - Andreas Seekamp
- Department of Trauma Surgery, University Medical Center of Schleswig-Holstein, Campus Kiel, Arnold-Heller-Strasse 3, 24105, Kiel, Germany
| | - Deike Varoga
- Department of Trauma Surgery, University Medical Center of Schleswig-Holstein, Campus Kiel, Arnold-Heller-Strasse 3, 24105, Kiel, Germany
| | - Tim Klüter
- Department of Trauma Surgery, University Medical Center of Schleswig-Holstein, Campus Kiel, Arnold-Heller-Strasse 3, 24105, Kiel, Germany.
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Bashir H, Seykora JT, Lee V. Invisible Shield: Review of the Corneal Epithelium as a Barrier to UV Radiation, Pathogens, and Other Environmental Stimuli. J Ophthalmic Vis Res 2017; 12:305-311. [PMID: 28791065 PMCID: PMC5525501 DOI: 10.4103/jovr.jovr_114_17] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The ocular surface is comprised of the cornea and conjunctiva, which are structures that not only protect the eye but also enable vision. The corneal epithelium is the most superficial layer of the cornea, and therefore first line of defense against external assaults. Damage to this highly specialized structure could lead to vision loss, making it an important structure to investigate and understand. Here, we conducted a search of the current literature on the mechanisms the corneal epithelium has adapted against three frequent insults: UV-radiation, pathogens, and environmental assaults. This review systematically examines the corneal epithelium's response to each assault in order to maintain its role as an invisible shield. The goal of this review is to provide insight into some of the critical functions the corneal epithelium performs that may be valuable to current regenerative studies.
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Affiliation(s)
- Hasan Bashir
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, USA
| | - John T Seykora
- Department of Dermatology, University of Pennsylvania, Philadelphia, USA
| | - Vivian Lee
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, USA.,Department of Dermatology, University of Pennsylvania, Philadelphia, USA
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24
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Mehlotra RK, Hall NB, Willie B, Stein CM, Weinberg A, Zimmerman PA, Vernon LT. Associations of Toll-Like Receptor and β-Defensin Polymorphisms with Measures of Periodontal Disease (PD) in HIV+ North American Adults: An Exploratory Study. PLoS One 2016; 11:e0164075. [PMID: 27727278 PMCID: PMC5058471 DOI: 10.1371/journal.pone.0164075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/19/2016] [Indexed: 11/28/2022] Open
Abstract
Polymorphisms in toll-like receptor (TLR) and β-defensin (DEFB) genes have been recognized as potential genetic factors that can influence susceptibility to and severity of periodontal diseases (PD). However, data regarding associations between these polymorphisms and PD are still scarce in North American populations, and are not available in HIV+ North American populations. In this exploratory study, we analyzed samples from HIV+ adults (n = 115), who received primary HIV care at 3 local outpatient HIV clinics and were monitored for PD status. We genotyped a total of 41 single nucleotide polymorphisms (SNPs) in 8 TLR genes and copy number variation (CNV) in DEFB4/103A. We performed regression analyses for levels of 3 periodontopathogens in subgingival dental plaques (Porphyromonas gingivalis [Pg], Treponema denticola [Td], and Tannerella forsythia [Tf]) and 3 clinical measures of PD (periodontal probing depth [PPD], gingival recession [REC], and bleeding on probing [BOP]). In all subjects combined, 2 SNPs in TLR1 were significantly associated with Td, and one SNP in TLR2 was significantly associated with BOP. One of the 2 SNPs in TLR1 was significantly associated with Td in Caucasians. In addition, another SNP in TLR1 and a SNP in TLR6 were also significantly associated with Td and Pg, respectively, in Caucasians. All 3 periodontopathogen levels were significantly associated with PPD and BOP, but none was associated with REC. Instrumental variable analysis showed that 8 SNPs in 6 TLR genes were significantly associated with the 3 periodontopathogen levels. However, associations between the 3 periodontopathogen levels and PPD or BOP were not driven by associations with these identified SNPs. No association was found between DEFB4/103A CNV and any periodontopathogen level or clinical measure in all samples, Caucasians, or African Americans. Our exploratory study suggests a role of TLR polymorphisms, particularly TLR1 and TLR6 polymorphisms, in PD in HIV+ North Americans.
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Affiliation(s)
- Rajeev K. Mehlotra
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- * E-mail: (RKM); (LTV)
| | - Noemi B. Hall
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Barne Willie
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Catherine M. Stein
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, United States of America
- Center for Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Aaron Weinberg
- Department of Biological Sciences, Case Western Reserve University School of Dental Medicine, Cleveland, Ohio, United States of America
| | - Peter A. Zimmerman
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Lance T. Vernon
- Department of Pediatric and Community Dentistry, Case Western Reserve University School of Dental Medicine, Cleveland, Ohio, United States of America
- * E-mail: (RKM); (LTV)
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25
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Reins RY, Baidouri H, McDermott AM. Vitamin D Activation and Function in Human Corneal Epithelial Cells During TLR-Induced Inflammation. Invest Ophthalmol Vis Sci 2016; 56:7715-27. [PMID: 26641549 DOI: 10.1167/iovs.15-17768] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
PURPOSE Vitamin D is recognized to be an important modulator of the immune system. In the eye, studies have shown that deficiencies and genetic differences in vitamin D-related genes have a significant impact on the development of various ocular diseases. Our current study examines the ability of human corneal epithelial cells (HCEC) to activate vitamin D and the effect of vitamin D treatment on antimicrobial peptide production and cytokine modulation during inflammation, with the ultimate goal of using vitamin D therapeutically for corneal inflammation. METHODS Human corneal epithelial cells were treated with 10-7M vitamin D3 (D3) or 25-hydroxyvitamin D3 (25D3) for 24 hours and 1,25-dihydroxyvitamin D3 (1,25D3) detected by immunoassay. Human cathelicidin (LL-37) expression was examined by RT-PCR, immunoblot, and immunostaining following 1,25D3 treatment and antimicrobial activity of 1,25D3-treated cells was determined. Cells were stimulated with TLR3 agonist polyinosinic-polycytidylic acid (Poly[I:C]) for 24 hours and cytokine levels measured by RT-PCR, ELISA, and Luminex. Immunostaining determined expression of vitamin D receptor (VDR) and retinoic acid inducible gene-1 receptor (RIG-1) as well as NF-κB nuclear translocation. RESULTS When treated with inactive vitamin D metabolites, HCEC produced active 1,25D3, leading to enhanced expression of the antimicrobial peptide, LL-37, dependent on VDR. 1,25-D3 decreased the expression of proinflammatory cytokines (IL-1β, IL-6, TNFα, and CCL20) and MMP-9 induced by Poly(I:C) as well as pattern recognition receptor expression (TLR3, RIG-1, MDA5). However, early activation of NF-κB was not affected. CONCLUSIONS These studies demonstrate the protective ability of vitamin D to attenuate proinflammatory mediators while increasing antimicrobial peptides and antipseudomonas activity in corneal cells, and further our knowledge on the immunomodulatory functions of the hormone.
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Zhao GQ, Qiu XY, Lin J, Li Q, Hu LT, Wang Q, Li H. Co-regulation of Dectin-1 and TLR2 in inflammatory response of human corneal epithelial cells induced by Aspergillus fumigates. Int J Ophthalmol 2016; 9:185-90. [PMID: 26949633 DOI: 10.18240/ijo.2016.02.01] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 07/06/2015] [Indexed: 01/30/2023] Open
Abstract
AIM To investigate the co-regulation of dendritic cell-associated C-type lectin-1 (Dectin-1), Toll-like receptor 2 (TLR2), and relative chemotactic factors in the Telomease-immortalized human corneal epithelial (THCE) cells after exposure to Aspergillus fumigatus (Af) hyphae. METHODS The normal THCE cells were investigated as control. After cultured in vitro with Af hyphae, with or without laminarin and anti-TLR2 antibody for 4, 8, 16 and 24h, THCE cells were harvested. The expression of Dectin-1, TLR2, CXCL1 and CXCL8 mRNA were measured by real-time quantitative polymerase chain reaction at the stimulation of 4, 8 and 16h separately. The protein expression of Dectin-1 and TLR2 were analyzed at 8, 16, and 24h by Western blot. RESULTS The mRNA expression of CXCL1 and CXCL8 increased in THCE cells after stimulated by Af hyphae. The stimulatory effects on these inflammatory chemokines were shown in a dose-dependent manner and reached the peak at 8h. Af hyphae significantly stimulated the production of Dectin-1 and TLR2 in THCE cells at both mRNA and protein levels. The protein of Dectin-1 and TLR2 gradually increased till 16h. While pretreated with laminarin (a Dectin-1 inhibitor), the expression of TLR2, CXCL1 and CXCL8 all decreased dramatically at the peak point. Interestingly, when pretreated with TLR2 neutralizing antibody, the expression of Dectin-1, CXCL1 and CXCL8 also decreased dramatically at the peak point. CONCLUSION These findings suggest that Dectin-1 and TLR2 co-regulated with each other after treated with inactive Af hyphae in the THCE cells, and they contribute together to the inflammatory responses by induction of chemokines CXCL1 and CXCL8.
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Affiliation(s)
- Gui-Qiu Zhao
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Xue-Yan Qiu
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Jing Lin
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Qing Li
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Li-Ting Hu
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Qian Wang
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Hui Li
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
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27
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Kaur A, Kumar V, Singh S, Singh J, Upadhyay N, Datta S, Singla S, Kumar V. Toll-like receptor-associated keratitis and strategies for its management. 3 Biotech 2015; 5:611-619. [PMID: 28324534 PMCID: PMC4569616 DOI: 10.1007/s13205-015-0280-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 01/27/2015] [Indexed: 11/16/2022] Open
Abstract
Keratitis is an inflammatory condition, characterized by involvement of corneal tissues. Most recurrent challenge of keratitis is infection. Bacteria, virus, fungus and parasitic organism have potential to cause infection. TLR are an important class of protein which has a major role in innate immune response to combat with pathogens. In last past years, extensive research efforts have provided considerable abundance information regarding the role of TLR in various types of keratitis. This paper focuses to review the recent literature illustrating amoebic, bacterial, fungal and viral keratitis associated with Toll-like receptor molecules and summarize existing thoughts on pathogenesis and treatment besides future probabilities for prevention against TLR-associated keratitis.
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Affiliation(s)
- Amandeep Kaur
- Department of Biotechnology, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Vijay Kumar
- Department of Chemistry, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Simranjeet Singh
- Department of Biotechnology, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Joginder Singh
- Department of Chemistry, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Niraj Upadhyay
- Department of Chemistry, Lovely Professional University, Phagwara, 144411, Punjab, India.
| | - Shivika Datta
- Department of Zoology, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Sourav Singla
- Department of Biotechnology, Lovely Professional University, Phagwara, 144411, Punjab, India
| | - Virender Kumar
- Department of Chemistry, Lovely Professional University, Phagwara, 144411, Punjab, India
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28
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Menon BB, Kaiser-Marko C, Spurr-Michaud S, Tisdale AS, Gipson IK. Suppression of Toll-like receptor-mediated innate immune responses at the ocular surface by the membrane-associated mucins MUC1 and MUC16. Mucosal Immunol 2015; 8:1000-8. [PMID: 25563498 PMCID: PMC4495011 DOI: 10.1038/mi.2014.127] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 12/01/2014] [Indexed: 02/04/2023]
Abstract
Membrane-associated mucins (MAMs) expressed on the ocular surface epithelium form a dense glycocalyx that is hypothesized to protect the cornea and conjunctiva from external insult. In this study, the hypothesis that the MAMs MUC1 and MUC16, expressed on the apical surface of the corneal epithelium, suppress Toll-like receptor (TLR)-mediated innate immune responses was tested. Using an in vitro model of corneal epithelial cells that are cultured to express MAMs, we show that reduced expression of either MUC1 or MUC16 correlates with increased message and secreted protein levels of the proinflammatory cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor-α (TNF-α) following exposure of cells to the TLR2 and TLR5 agonists, heat-killed Listeria monocytogenes and flagellin, respectively. As mice express Muc1 (but not Muc16) in the corneal epithelium, a Muc1(-/-) mouse model was used to extend in vitro findings. Indeed, IL-6 and TNF-α message levels were increased in the corneal epithelium of Muc1(-/-) mice, in comparison with wild-type mice, following exposure of enucleated eyes to the TLR2 and TLR5 agonists. Our results suggest that the MAMs MUC1 and MUC16 contribute to the maintenance of immune homeostasis at the ocular surface by limiting TLR-mediated innate immune responses.
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Affiliation(s)
- Balaraj B. Menon
- Address correspondence to: Balaraj B. Menon, Ph.D., Schepens Eye Research Institute, Massachusetts Eye and Ear, 20 Staniford St., Boston, MA 02114, Tel: 617-912-0217,
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29
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Taube MA, del Mar Cendra M, Elsahn A, Christodoulides M, Hossain P. Pattern recognition receptors in microbial keratitis. Eye (Lond) 2015; 29:1399-415. [PMID: 26160532 DOI: 10.1038/eye.2015.118] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 05/31/2015] [Indexed: 12/12/2022] Open
Abstract
Microbial keratitis is a significant cause of global visual impairment and blindness. Corneal infection can be caused by a wide variety of pathogens, each of which exhibits a range of mechanisms by which the immune system is activated. The complexity of the immune response to corneal infection is only now beginning to be elucidated. Crucial to the cornea's defences are the pattern-recognition receptors: Toll-like and Nod-like receptors and the subsequent activation of inflammatory pathways. These inflammatory pathways include the inflammasome and can lead to significant tissue destruction and corneal damage, with the potential for resultant blindness. Understanding the immune mechanisms behind this tissue destruction may enable improved identification of therapeutic targets to aid development of more specific therapies for reducing corneal damage in infectious keratitis. This review summarises current knowledge of pattern-recognition receptors and their downstream pathways in response to the major keratitis-causing organisms and alludes to potential therapeutic approaches that could alleviate corneal blindness.
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Affiliation(s)
- M-A Taube
- Division of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.,University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - M del Mar Cendra
- Division of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - A Elsahn
- Division of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.,University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - M Christodoulides
- Division of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - P Hossain
- Division of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.,University Hospital Southampton NHS Foundation Trust, Southampton, UK
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30
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Roy S, Marla S, Praneetha DC. Recognition of Corynebacterium pseudodiphtheriticum by Toll-like receptors and up-regulation of antimicrobial peptides in human corneal epithelial cells. Virulence 2015; 6:716-21. [PMID: 26125127 DOI: 10.1080/21505594.2015.1066063] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Bacterial keratitis is a major cause of corneal ulcers in developing and industrialized nations. In this study, we examined the host innate immune responses to Corynebacterium pseudodiphtheriticum, often overlooked as commensal, in human corneal epithelial cells. The expressions of innate immune mediators were determined by quantitative PCR from corneal ulcers of patients and immortalized human corneal epithelial cells (HCEC). We have found an elevated expression of Toll like receptors (TLRs) along with IL-6 and IL-1β from both ulcers and epithelial cells infected with C. pseudodiphtheriticum. Activation of NF-κB and MAPK signaling pathways were also observed in HCEC in response to C. pseudodiphtheriticum. In addition, we found a significant increase in the expression of antimicrobial peptides S100A8, S100A9 and human β-defensin 1 from both corneal ulcers and HCEC.
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Affiliation(s)
- Sanhita Roy
- a Prof. Brien Holden Eye Research Center; Hyderabad Eye Research Foundation; LV Prasad Eye Institute ; Hyderabad , India
| | - Sushma Marla
- a Prof. Brien Holden Eye Research Center; Hyderabad Eye Research Foundation; LV Prasad Eye Institute ; Hyderabad , India
| | - D C Praneetha
- a Prof. Brien Holden Eye Research Center; Hyderabad Eye Research Foundation; LV Prasad Eye Institute ; Hyderabad , India
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31
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Eghrari AO, Riazuddin SA, Gottsch JD. Overview of the Cornea: Structure, Function, and Development. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:7-23. [PMID: 26310146 DOI: 10.1016/bs.pmbts.2015.04.001] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The cornea is a transparent tissue with significant refractive and barrier functions. The epithelium serves as the principal barrier to fluid and pathogens, a function performed through production of tight junctions, and constant repopulation through differentiation and maturation of dividing cells in its basal cell layer. It is supported posteriorly by basement membrane and Bowman's layer and assists in maintenance of stromal dehydration. The stroma composes the majority of corneal volume, provides support and clarity, and assists in ocular immunity. The posterior cornea, composed of Descemet membrane and endothelium, is essential for stromal dehydration, maintained through tight junctions and endothelial pumps. Corneal development begins with primitive formation of epithelium and lens, followed by waves of migration from cells of neural crest origin between these two structures to produce the stroma and endothelium. Descemet membrane is secreted by the latter and gradually thickens.
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Affiliation(s)
- Allen O Eghrari
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - S Amer Riazuddin
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - John D Gottsch
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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32
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Machado LR, Ottolini B. An evolutionary history of defensins: a role for copy number variation in maximizing host innate and adaptive immune responses. Front Immunol 2015; 6:115. [PMID: 25852686 PMCID: PMC4364288 DOI: 10.3389/fimmu.2015.00115] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/01/2015] [Indexed: 12/21/2022] Open
Abstract
Defensins represent an evolutionary ancient family of antimicrobial peptides that play diverse roles in human health and disease. Defensins are cationic cysteine-containing multifunctional peptides predominantly expressed by epithelial cells or neutrophils. Defensins play a key role in host innate immune responses to infection and, in addition to their classically described role as antimicrobial peptides, have also been implicated in immune modulation, fertility, development, and wound healing. Aberrant expression of defensins is important in a number of inflammatory diseases as well as modulating host immune responses to bacteria, unicellular pathogens, and viruses. In parallel with their role in immunity, in other species, defensins have evolved alternative functions, including the control of coat color in dogs. Defensin genes reside in complex genomic regions that are prone to structural variations and some defensin family members exhibit copy number variation (CNV). Structural variations have mediated, and continue to influence, the diversification and expression of defensin family members. This review highlights the work currently being done to better understand the genomic architecture of the β-defensin locus. It evaluates current evidence linking defensin CNV to autoimmune disease (i.e., Crohn’s disease and psoriasis) as well as the contribution CNV has in influencing immune responses to HIV infection.
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Affiliation(s)
- Lee R Machado
- Institute of Health and Wellbeing, School of Health, University of Northampton , Northampton , UK
| | - Barbara Ottolini
- Department of Cancer Studies, University of Leicester , Leicester , UK
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33
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The importance of the Pseudomonas aeruginosa type III secretion system in epithelium traversal depends upon conditions of host susceptibility. Infect Immun 2015; 83:1629-40. [PMID: 25667266 DOI: 10.1128/iai.02329-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Pseudomonas aeruginosa is invasive or cytotoxic to host cells, depending on the type III secretion system (T3SS) effectors encoded. While the T3SS is known to be involved in disease in vivo, how it participates remains to be clarified. Here, mouse models of superficial epithelial injury (tissue paper blotting with EGTA treatment) and immunocompromise (MyD88 deficiency) were used to study the contribution of the T3SS transcriptional activator ExsA to epithelial traversal. Corneas of excised eyeballs were inoculated with green fluorescent protein (GFP)-expressing PAO1 or isogenic exsA mutants for 6 h ex vivo before bacterial traversal and epithelial thickness were quantified by using imaging. In the blotting-EGTA model, exsA mutants were defective in capacity for traversal. Accordingly, an ∼16-fold variability in exsA expression among PAO1 isolates from three sources correlated with epithelial loss. In contrast, MyD88-/- epithelia remained susceptible to P. aeruginosa traversal despite exsA mutation. Epithelial lysates from MyD88-/- mice had reduced antimicrobial activity compared to those from wild-type mice with and without prior antigen challenge, particularly 30- to 100-kDa fractions, for which mass spectrometry revealed multiple differences, including (i) lower baseline levels of histones, tubulin, and lumican and (ii) reduced glutathione S-transferase, annexin, and dermatopontin, after antigen challenge. Thus, the importance of ExsA in epithelial traversal by invasive P. aeruginosa depends on the compromise enabling susceptibility, suggesting that strategies for preventing infection will need to extend beyond targeting the T3SS. The data also highlight the importance of mimicking conditions allowing susceptibility in animal models and the need to monitor variability among bacterial isolates from different sources, even for the same strain.
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Eslani M, Movahedan A, Afsharkhamseh N, Sroussi H, Djalilian AR. The role of toll-like receptor 4 in corneal epithelial wound healing. Invest Ophthalmol Vis Sci 2014; 55:6108-15. [PMID: 25183764 DOI: 10.1167/iovs.14-14736] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
PURPOSE We evaluated the role of Toll-like receptor 4 (TLR4) in corneal epithelial wound healing. METHODS The expression of TLR4 during in vivo corneal epithelial wound healing was examined by immunostaining in mice. The expression and activation of TLR4 was studied in primary or telomerase-immortalized human corneal epithelial cells (HCEC). Scratch assay was performed to evaluate in vitro wound closure using live time-lapse microscopy. Transwell migration assay and Ki67 immunostaining were done to evaluate migration and proliferation, respectively. Lipopolysaccharide (LPS) was used to activate TLR4, whereas CLI-095 was used for its inhibition. The expression of inflammatory cytokines was determined by RT-PCR and ELISA. The activation of p42/44 and p38 was determined by immunoblotting. RESULTS In the murine model, TLR4 immunostaining was noted prominently in the epithelium 8 hours after wounding. There was a 4-fold increase in the expression of TLR4 6 hours after in vitro scratch wounding (P < 0.001). Confocal microscopy confirmed the membrane localization of TLR4/MD2 complex. There was a significant increase in migration, proliferation, and wound closure in HCEC treated with LPS (P < 0.05), while there was significant decrease with TLR4 inhibition (P < 0.05). Addition of LPS to wounded HCEC resulted in a significant increase in the expression of IL-6, TNF-α, CXCL8/IL8, and CCL5/RANTES at the mRNA and protein levels. Likewise, LPS increased the activation of p42/44 and p38 in wounded HCEC. CONCLUSIONS These results suggest that epithelial wounding induces the expression of functional TLR4. Toll-like receptor 4 signaling appears to contribute to early corneal epithelial wound repair by enhancing migration and proliferation.
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Affiliation(s)
- Medi Eslani
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Asadolah Movahedan
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Neda Afsharkhamseh
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Herve Sroussi
- Oral Medicine and Diagnostic Sciences, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Ali R Djalilian
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States
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35
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McClure R, Massari P. TLR-Dependent Human Mucosal Epithelial Cell Responses to Microbial Pathogens. Front Immunol 2014; 5:386. [PMID: 25161655 PMCID: PMC4129373 DOI: 10.3389/fimmu.2014.00386] [Citation(s) in RCA: 186] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 07/29/2014] [Indexed: 12/17/2022] Open
Abstract
Toll-like receptor (TLR) signaling represents one of the best studied pathways to implement defense mechanisms against invading microbes in human being as well as in animals. TLRs respond to specific microbial ligands and to danger signals produced by the host during infection, and initiate downstream cascades that activate both innate and adaptive immunity. TLRs are expressed by professional immune cells and by the large majority of non-hematopoietic cells, including epithelial cells. In epithelial tissues, TLR functions are particularly important because these sites are constantly exposed to microorganisms, due to their location at the host interface with the environment. While at these sites specific defense mechanisms and inflammatory responses are initiated via TLR signaling against pathogens, suppression or lack of TLR activation is also observed in response to the commensal microbiota. The mechanisms by which TLR signaling is regulated in mucosal epithelial cells include differential expression and levels of TLRs (and their signaling partners), their cellular localization and positioning within the tissue in a fashion that favors responses to pathogens while dampening responses to commensals and maintaining tissue homeostasis in physiologic conditions. In this review, the expression and activation of TLRs in mucosal epithelial cells of several sites of the human body are examined. Specifically, the oral cavity, the ear canal and eye, the airways, the gut, and the reproductive tract are discussed, along with how site-specific host defense mechanisms are implemented via TLR signaling.
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Affiliation(s)
- Ryan McClure
- Department of Microbiology, Boston University School of Medicine , Boston, MA , USA
| | - Paola Massari
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine , Boston, MA , USA
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Dua HS, Otri AM, Hopkinson A, Mohammed I. In vitro studies on the antimicrobial peptide human beta-defensin 9 (HBD9): signalling pathways and pathogen-related response (an American Ophthalmological Society thesis). TRANSACTIONS OF THE AMERICAN OPHTHALMOLOGICAL SOCIETY 2014; 112:50-73. [PMID: 25646028 PMCID: PMC4311673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
PURPOSE Human β-defensins (HBDs) are an important part of the innate immune host defense at the ocular surface. Unlike other defensins, expression of HBD9 at the ocular surface is reduced during microbial infection, but activation of toll-like receptor 2 (TLR2) in corneal epithelial cells has been shown to up-regulate HBD9. Our purpose was to test the hypothesis that TLR2 has a key role in the signalling pathway(s) involved in the overexpression or underexpression of HBD9, and accordingly, different pathogens would induce a different expression pattern of HBD9. METHODS The in vitro RNAi silencing method and response to dexamethasone were used to determine key molecules involved in signalling pathways of HBD9 in immortalized human corneal epithelial cells. The techniques included cell culture with exposure to specific transcription factor inhibitors and bacteria, RNA extraction and cDNA synthesis, quantitative real-time polymerase chain reaction, and immunohistology. RESULTS This study demonstrates that TLR2 induces HBD9 mRNA and protein expression in a time- and dose-dependent manner. Transforming growth factor-β-activated kinase 1 (TAK1) plays a central role in HBD9 induction by TLR2, and transcription factors c-JUN and activating transcription factor 2 are also involved. Dexamethasone reduces TLR2-mediated up-regulation of HBD9 mRNA and protein levels in mitogen-activated protein kinase phosphatase 1 (MKP1)-dependent and c-JUN-independent manner. HBD9 expression differs with gram-negative and gram-positive bacteria. CONCLUSIONS TLR2-mediated MKPs and nuclear factor-κB signalling pathways are involved in HBD9 expression. TAK-1 is a key molecule. These molecules can be potentially targeted to modulate HBD9 expression. Differential expression of HBD9 with different bacteria could be related to differences in pathogen-associated molecular patterns of these organisms.
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Affiliation(s)
- Harminder S Dua
- Academic Department of Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, England
| | - Ahmad Muneer Otri
- Academic Department of Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, England
| | - Andrew Hopkinson
- Academic Department of Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, England
| | - Imran Mohammed
- Academic Department of Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, England
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Jeong MS, Kim JY, Lee HI, Seo SJ. Calcitriol May Down-Regulate mRNA Over-Expression of Toll-Like Receptor-2 and -4, LL-37 and Proinflammatory Cytokines in Cultured Human Keratinocytes. Ann Dermatol 2014; 26:296-302. [PMID: 24966627 PMCID: PMC4069638 DOI: 10.5021/ad.2014.26.3.296] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 03/19/2013] [Accepted: 04/27/2013] [Indexed: 11/12/2022] Open
Abstract
Background Although vitamin D analogs have been used in the topical treatment of psoriasis, their mechanisms of action are not well understand. Calcitriol, the hormonally active vitamin D3 metabolite, has been demonstrated to exert immunomodulatory effects in the skin by down-regulating the expression of Toll-like receptors (TLRs) and proinflammatory cytokines. Objective We investigated the effects of calcitriol on the expression of TLR2, TLR4, antimicrobial peptide LL-37, and proinflammatory cytokines in cultured human keratinocytes. Methods The mRNA expression levels of TLR2, TLR4, tumor necrosis factor α (TNF-α), interleukin (IL)-1β and LL-37 in cultured human keratinocytes were measured by real-time polymerase chain reaction (PCR) and reverse transcription (RT). Furthermore, we measured supernatant TNF-α levels by an enzyme-linked immunosorbent assay (ELISA) to confirm the effects of calcitriol on TLR2 and TLR4. Results As measured by RT-PCR and real-time PCR, calcitriol was found to suppress the lipopolysaccharide- and ultraviolet B radiation-mediated induction of expression of TLRs, LL-37 and proinflammatory cytokines such as TNF-α and IL-1β in normal human keratinocytes. The supernatant TNF-α levels measured by ELISA were also suppressed after treatment with calcitriol. Conclusion Calcitriol may down-regulate inflammatory stated over-expression of LL-37 and proinflammatory cytokines.
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Affiliation(s)
- Mi Sook Jeong
- Department of Dermatology, Chung-Ang University Hospital, Seoul, Korea
| | - Ji-Yun Kim
- Department of Dermatology, Chung-Ang University Hospital, Seoul, Korea
| | - He In Lee
- Department of Dermatology, Chung-Ang University Hospital, Seoul, Korea
| | - Seong Jun Seo
- Department of Dermatology, Chung-Ang University Hospital, Seoul, Korea
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Mear JB, Gosset P, Kipnis E, Faure E, Dessein R, Jawhara S, Fradin C, Faure K, Poulain D, Sendid B, Guery B. Candida albicans airway exposure primes the lung innate immune response against Pseudomonas aeruginosa infection through innate lymphoid cell recruitment and interleukin-22-associated mucosal response. Infect Immun 2014; 82:306-15. [PMID: 24166952 PMCID: PMC3911865 DOI: 10.1128/iai.01085-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 10/21/2013] [Indexed: 01/21/2023] Open
Abstract
Pseudomonas aeruginosa and Candida albicans are two pathogens frequently encountered in the intensive care unit microbial community. We have demonstrated that C. albicans airway exposure protected against P. aeruginosa-induced lung injury. The goal of the present study was to characterize the cellular and molecular mechanisms associated with C. albicans-induced protection. Airway exposure by C. albicans led to the recruitment and activation of natural killer cells, innate lymphoid cells (ILCs), macrophages, and dendritic cells. This recruitment was associated with the secretion of interleukin-22 (IL-22), whose neutralization abolished C. albicans-induced protection. We identified, by flow cytometry, ILCs as the only cellular source of IL-22. Depletion of ILCs by anti-CD90.2 antibodies was associated with a decreased IL-22 secretion and impaired survival after P. aeruginosa challenge. Our results demonstrate that the production of IL-22, mainly by ILCs, is a major and inducible step in protection against P. aeruginosa-induced lung injury. This cytokine may represent a clinical target in Pseudomonas aeruginosa-induced lung injury.
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Affiliation(s)
- Jean Baptiste Mear
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
| | - Philippe Gosset
- Institut Pasteur de Lille, Centre d'Infection et d'Immunité de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique, UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale, Lille, France
- Institut Fédératif de Recherche, Lille, France
| | - Eric Kipnis
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
| | - Emmanuel Faure
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
| | - Rodrigue Dessein
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
| | - Samir Jawhara
- INSERM U995, Regulation of Candida Cell Wall Glycan-Host Interface, Faculté de Médecine de Lille, Université Lille Nord de France, CHRU de Lille, Lille, France
| | - Chantal Fradin
- INSERM U995, Regulation of Candida Cell Wall Glycan-Host Interface, Faculté de Médecine de Lille, Université Lille Nord de France, CHRU de Lille, Lille, France
| | - Karine Faure
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
| | - Daniel Poulain
- INSERM U995, Regulation of Candida Cell Wall Glycan-Host Interface, Faculté de Médecine de Lille, Université Lille Nord de France, CHRU de Lille, Lille, France
| | - Boualem Sendid
- INSERM U995, Regulation of Candida Cell Wall Glycan-Host Interface, Faculté de Médecine de Lille, Université Lille Nord de France, CHRU de Lille, Lille, France
| | - Benoit Guery
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
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Yoon GS, Dong C, Gao N, Kumar A, Standiford TJ, Yu FSX. Interferon regulatory factor-1 in flagellin-induced reprogramming: potential protective role of CXCL10 in cornea innate defense against Pseudomonas aeruginosa infection. Invest Ophthalmol Vis Sci 2013; 54:7510-21. [PMID: 24130180 DOI: 10.1167/iovs.13-12453] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE We previously showed that pre-exposure of the cornea to Toll-like receptor (TLR)5 ligand flagellin induces strong protective innate defense against microbial pathogens and hypothesized that flagellin modulates gene expression at the transcriptional levels. Thus, we sought to determine the role of one transcription factor, interferon regulatory factor (IRF1), and its target gene CXCL10 therein. METHODS Superarray was used to identify transcription factors differentially expressed in Pseudomonas aeruginosa-challenged human corneal epithelial cells (CECs) with or without flagellin pretreatment. The expression of CXCL10, IRF1, LI-8(CXCL2), and IFNγ was determined by PCR, immunohistochemistry, Western/dot blotting, and/or ELISA. IRF1 knockout mice, CXCL10 and IFNγ neutralization, and NK cell depletion were used to define in vivo regulation and function of CXCL10. The severity of P. aeruginosa was assessed using clinical scoring, slit-lamp microscopy, bacterial counting, polymorphonuclear leukocytes (PMN) infiltration, and macrophage inflammatory protein 2/Chemokine (C-X-C motif) ligand 2 (MIP-2/CXCL2) expression. RESULTS Flagellin pretreatment drastically affected P. aeruginosa-induced IRF1 expression in human CECs. However, flagellin pretreatment augmented the P. aeruginosa-induced expression of Irf1 and its target gene Cxcl10 in B6 mouse corneas. Irf1 deficiency reduced infection-triggered CXCL10 expression, increased keratitis severity, and attenuated flagellin-elicited protection compared to values in wild-type (WT) controls. CXCL10 neutralization in the cornea of WT mice displayed pathogenesis similar to that of IRF1⁻/⁻ mice. IFNγ receptor neutralization and NK cell depletion prevented flagellin-augmented IRF1 and CXCL10 expression and increased the susceptibility to P. aeruginosa infection in mouse corneas. CONCLUSIONS IRF1 plays a role in the corneal innate immune response by regulating CXCL10 expression. IFNγ-producing NK cells augment the epithelial expression of IRF1 and CXCL10 and thus contribute to the innate defense of the cornea against P. aeruginosa infection.
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Affiliation(s)
- Gi Sang Yoon
- Department of Anatomy and Cell Biology, Kresge Eye Institute, Wayne State University, Detroit, Michigan
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Pearlman E, Sun Y, Roy S, Karmakar M, Hise AG, Szczotka-Flynn L, Ghannoum M, Chinnery HR, McMenamin PG, Rietsch A. Host defense at the ocular surface. Int Rev Immunol 2013; 32:4-18. [PMID: 23360155 DOI: 10.3109/08830185.2012.749400] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Microbial infections of the cornea frequently cause painful, blinding and debilitating disease that is often difficult to treat and may require corneal transplantation. In addition, sterile corneal infiltrates that are associated with contact lens wear cause pain, visual impairment and photophobia. In this article, we review the role of Toll-Like Receptors (TLR) in bacterial keratitis and sterile corneal infiltrates, and describe the role of MD-2 regulation in LPS responsiveness by corneal epithelial cells. We conclude that both live bacteria and bacterial products activate Toll-Like Receptors in the cornea, which leads to chemokine production and neutrophil recruitment to the corneal stroma. While neutrophils are essential for bacterial killing, they also cause tissue damage that results in loss of corneal clarity. These disparate outcomes, therefore, represent a spectrum of disease severity based on this pathway, and further indicate that targeting the TLR pathway is a feasible approach to treating inflammation caused by live bacteria and microbial products. Further, as the P. aeruginosa type III secretion system (T3SS) also plays a critical role in disease pathogenesis by inducing neutrophil apoptosis and facilitating bacterial growth in the cornea, T3SS exotoxins are additional targets for therapy for P. aeruginosa keratitis.
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Affiliation(s)
- Eric Pearlman
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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Shi L, Yu X, Yang H, Wu X. Advanced glycation end products induce human corneal epithelial cells apoptosis through generation of reactive oxygen species and activation of JNK and p38 MAPK pathways. PLoS One 2013; 8:e66781. [PMID: 23776698 PMCID: PMC3680386 DOI: 10.1371/journal.pone.0066781] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 05/13/2013] [Indexed: 01/02/2023] Open
Abstract
Advanced Glycation End Products (AGEs) has been implicated in the progression of diabetic keratopathy. However, details regarding their function are not well understood. In the present study, we investigated the effects of intracellular reactive oxygen species (ROS) and JNK, p38 MAPK on AGE-modified bovine serum albumin (BSA) induced Human telomerase-immortalized corneal epithelial cells (HUCLs) apoptosis. We found that AGE-BSA induced HUCLs apoptosis and increased Bax protein expression, decreased Bcl-2 protein expression. AGE-BSA also induced the expression of receptor for advanced glycation end product (RAGE). AGE-BSA-RAGE interaction induced intracellular ROS generation through activated NADPH oxidase and increased the phosphorylation of p47phox. AGE-BSA induced HUCLs apoptosis was inhibited by pretreatment with NADPH oxidase inhibitors, ROS quencher N-acetylcysteine (NAC) or neutralizing anti-RAGE antibodies. We also found that AGE-BSA induced JNK and p38 MAPK phosphorylation. JNK and p38 MAPK inhibitor effectively blocked AGE-BSA-induced HUCLs apoptosis. In addition, NAC completely blocked phosphorylation of JNK and p38 MAPK induced by AGE-BSA. Our results indicate that AGE-BSA induced HUCLs apoptosis through generation of intracellular ROS and activation of JNK and p38 MAPK pathways.
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Affiliation(s)
- Long Shi
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan, China
| | - Xiaoming Yu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan, China
| | - Hongling Yang
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, China
| | - Xinyi Wu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, China
- * E-mail:
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Takeda S, Yamaai T, Kaneda Y, Mizukawa N, Iida S, Fujimaki H. Toluene Exposure Leads to a Change in Expression Patterns of β Defensins in the Mouse Tracheal Epithelium. J Toxicol Pathol 2013; 26:35-40. [PMID: 23723566 PMCID: PMC3620212 DOI: 10.1293/tox.26.35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 12/05/2012] [Indexed: 11/25/2022] Open
Abstract
Defensins are generally implicated in the quick resistance of epithelial surfaces to microbials; however, recent reports have indicated that defensins also have unknown purposes in relation to noninfectious diseases. In this study, the localization patterns of anti-microbial peptides, β defensins (BDs), in the tracheal epithelium of male C3H mice under exposure to toluene were analyzed by immunohistochemistry. Mice were exposed one to ten times to toluene for 30 min by nose-only inhalation. Expression of BDs was revealed by immunohistochemistry in serial sections of trachea after the final exposure. Expression of BD-1 was usually observed at almost the same levels in all exposure groups, and expression of BD-2 was observed in the control group; however, the signals for BD-2 decreased gradually with frequency of exposure. In the group exposed ten times, expression of BD-2 decreased to far lower than that of the control group. No expression of BD-3 was detected in any groups. Interestingly, expression of BD-4 increased to the maximum in the group exposed four times and decreased to a level lower than that of the control in the group exposed ten times. The results of the present study indicated that toluene gas might change the expression pattern of BDs in the tracheal epithelial cells. The oscillation of expression of BD-4 was quite characteristic and might contribute to morphological damage in on the epithelial cells.
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Affiliation(s)
- Seiko Takeda
- Department of Oral and Maxillofacial Reconstructive Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
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Semlali A, Witoled C, Alanazi M, Rouabhia M. Whole cigarette smoke increased the expression of TLRs, HBDs, and proinflammory cytokines by human gingival epithelial cells through different signaling pathways. PLoS One 2012; 7:e52614. [PMID: 23300722 PMCID: PMC3532503 DOI: 10.1371/journal.pone.0052614] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 11/19/2012] [Indexed: 11/19/2022] Open
Abstract
The gingival epithelium is becoming known as a regulator of the oral innate immune responses to a variety of insults such as bacteria and chemicals, including those chemicals found in cigarette smoke. We investigated the effects of whole cigarette smoke on cell-surface-expressed Toll-like receptors (TLR)-2, -4 and -6, human β-defensin (HBD) and proinflammatory cytokine expression and production in primary human gingival epithelial cells. Whole cigarette smoke was shown to increase TLR2, TLR4 and TLR6 expression. Cigarette smoke led to ERK1/2, p38 and JNK phosphorylation in conjunction with nuclear factor-κB (NFκB) translocation into the nucleus. TLR expression following cigarette smoke exposure was down regulated by the use of ERK1/2, p38, JNK MAP kinases, and NFκB inhibitors, suggesting the involvement of these signaling pathways in the cellular response against cigarette smoke. Cigarette smoke also promoted HBD2, HBD3, IL-1β, and IL-6 expression through the ERK1/2 and NFκB pathways. Interestingly, the modulation of TLR, HBD, and cytokine expression was maintained long after the gingival epithelial cells were exposed to smoke. By promoting TLR, HBDs, and proinflammatory cytokine expression and production, cigarette smoke may contribute to innate immunity dysregulation, which may have a negative effect on human health.
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Affiliation(s)
- Abdelhabib Semlali
- Groupe de Recherche en Écologie Buccale, Département de stomatologie, Faculté de Médecine Dentaire, Université Laval, Québec, Québec, Canada
- Genome Research Chair, Department of Biochemistry, College of Science King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Chmielewski Witoled
- Groupe de Recherche en Écologie Buccale, Département de stomatologie, Faculté de Médecine Dentaire, Université Laval, Québec, Québec, Canada
| | - Mohammed Alanazi
- Genome Research Chair, Department of Biochemistry, College of Science King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Mahmoud Rouabhia
- Groupe de Recherche en Écologie Buccale, Département de stomatologie, Faculté de Médecine Dentaire, Université Laval, Québec, Québec, Canada
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Zhou R, Zhang R, Sun Y, Platt S, Szczotka-Flynn L, Pearlman E. Innate immune regulation of Serratia marcescens-induced corneal inflammation and infection. Invest Ophthalmol Vis Sci 2012; 53:7382-8. [PMID: 23033384 DOI: 10.1167/iovs.12-10238] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Serratia marcescens is frequently isolated from lenses of patients with contact lens-associated corneal infiltrates. In the current study, we examined the role of toll-like receptors (TLRs) and interleukin-1 receptor type 1 (IL-1R1) in S. marcescens-induced corneal inflammation and infection. METHODS The central corneal epithelium of C57BL/6 and gene knockout mice was abraded, and 1 × 10(7) S. marcescens were added in the presence of a silicone hydrogel contact lens, and we examined corneal inflammation by confocal microscopy and neutrophil enumeration. Viable bacteria were quantified by colony-forming units (CFU). RESULTS S. marcescens induced neutrophil recruitment to the corneal stroma, and increased corneal thickness and haze in C57BL/6 mice. Conversely, CFU was significantly lower by 48 hours post infection. In contrast, MyD88(-/-), IL-1R(-/-), TLR4(-/-), and TLR4/5(-/-) corneas infected with S. marcescens had significantly increased CFU, indicating impaired clearance. However, there was no significant difference in CFU among C57BL/6, TIRAP(-/-), and TRIF(-/-) mice. Tobramycin-killed S. marcescens induced corneal inflammation in C57BL/6 mice, which was impaired significantly in MD-2(-/-) mice and in C57BL/6 mice pretreated topically with the MD-2 antagonist eritoran tetrasodium. CONCLUSIONS S. marcescens induces corneal inflammation by activation of TLR4/MD-2/MyD88 and the IL-1R1/MyD88 pathways, which are potential therapeutic targets for inhibition of S. marcescens-induced corneal inflammation.
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Affiliation(s)
- Rong Zhou
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio 44106, USA
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In vitro evidence of involvement of the epithelial y+ transporter in β-defensin production on the ocular surface. Ann Anat 2011; 193:479-85. [PMID: 22056339 DOI: 10.1016/j.aanat.2011.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 10/06/2011] [Accepted: 10/08/2011] [Indexed: 11/21/2022]
Abstract
To analyse the hypothesis as to whether there is a functional relationship between human cationic amino acid transporters (hCATs, y(+) transporter, the main transporter of L-arginine and L-lysine) and human β-defensin (important components of immune function) production on the ocular surface, arginase and nitrate monoxide synthase (NOS), enzymes that compete for L-arginine, were inhibited by norNOHA (N(omega)-hydroxy-nor-L-arginine) and/or L-NAME (NG-nitro-L-arginine methyl ester) in cultured human corneal epithelial cells. In addition, the transport activity of hCAT proteins was inhibited or activated through α-tocopherol or PMA (phorbol myristate acetate), respectively. Concentrations of the human inducible β-defensins (hBD) 2 and 3 were determined by ELISA experiments. The basic expression of hBD3 in non-stimulated HCE cells significantly exceeded that of hBD2. Both β-defensins also differed as to how readily their excretion could be stimulated. HBD2 excretion rate was 3.5 time more by L-NAME, whereas norNOHA had no effect. In contrast, hBD3 excretion was increased by norNOHA by a factor of 1.5 but L-NAME alone had no effect. The excretion of both β-defensins was increased 3- and 6-fold by combined administration of L-NAME, norNOHA and interleukin (IL)-1β. Administration of α-tocopherol increased hBD2 excretion twofold. No effect was observed for hBD3. With PMA, on the other hand, a reduction in secretion for both β-defensins was observed. These in vitro findings provide evidence of a functional association between CAT proteins and β-defensins 2 and 3 opening up a new field of research with pharmacological perspectives for treatment of inflammatory diseases such as keratitis or dry eye disease.
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Kolar SS, McDermott AM. Role of host-defence peptides in eye diseases. Cell Mol Life Sci 2011; 68:2201-13. [PMID: 21584809 PMCID: PMC3637883 DOI: 10.1007/s00018-011-0713-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 04/26/2011] [Accepted: 04/26/2011] [Indexed: 10/18/2022]
Abstract
The eye and its associated tissues including the lacrimal system and lids have evolved several defence mechanisms to prevent microbial invasion. Included among this armory are several host-defence peptides. These multifunctional molecules are being studied not only for their endogenous antimicrobial properties but also for their potential therapeutic effects. Here the current knowledge of host-defence peptide expression in the eye will be summarised. The role of these peptides in eye disease will be discussed with the primary focus being on infectious keratitis, inflammatory conditions including dry eye and wound healing. Finally the potential of using host-defence peptides and their mimetics/derivatives for the treatment and prevention of eye diseases is addressed.
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Affiliation(s)
- Satya S. Kolar
- College of Optometry, University of Houston, 4901 Calhoun Road, 505 J Davis Armistead Bldg, Houston, TX 77204-2020 USA
| | - Alison M. McDermott
- College of Optometry, University of Houston, 4901 Calhoun Road, 505 J Davis Armistead Bldg, Houston, TX 77204-2020 USA
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Guo H, Gao J, Wu X. Toll-like receptor 2 siRNA suppresses corneal inflammation and attenuates Aspergillus fumigatus keratitis in rats. Immunol Cell Biol 2011; 90:352-7. [PMID: 21647173 DOI: 10.1038/icb.2011.49] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Toll-like receptors (TLRs) are key components of innate immunity that detect microbial infection and trigger host defense responses. However, they are capable of initiating both protective and damaging immune responses, as exaggerated expression of inflammatory components can have devastating effects on the host. We previously reported that TLR2 in corneal epithelium has an important role in the pathogenesis of fungal keratitis, however, how the corneal inflammation is modulated remains to be elucidated. This study aims to investigate the effect of targeting TLR2 on Aspergillus fumigatus keratitis in rats. The control or TLR2 small interfering RNA (siRNA) was applied sub-conjunctively and topically to the cornea. TLR2 immunostaining was performed to determine the feasibility of TLR2 siRNA delivery. Production of inflammatory cytokines and chemokines were determined by real-time quantitative PCR. Polymorphonuclear leukocyte (PMN) infiltration was assessed by myeloperoxidase activity. It was found that rat corneas treated with TLR2 siRNA showed a significant reduction of TLR2 expression in corneal epithelium. TLR2 siRNA treatment improved the outcome of keratitis, which was characterized by decreased corneal opacity, less corneal perforation, suppressed PMN infiltration, reduced production of inflammatory cytokines and chemokines, and less fungal burden. In conclusion, TLR2 siRNA treatment attenuated A. fumigatus keratitis by suppressing corneal inflammation and preventing fungal invasion, suggesting a novel avenue to control fungal infection and avert damage caused by excessive inflammation.
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Affiliation(s)
- Hui Guo
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, PR China
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Shamsuddin N, Kumar A. TLR2 mediates the innate response of retinal Muller glia to Staphylococcus aureus. THE JOURNAL OF IMMUNOLOGY 2011; 186:7089-97. [PMID: 21602496 DOI: 10.4049/jimmunol.1100565] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Muller cells, the principal glia of the retina, play several key roles in normal and various retinal diseases. To date, their direct involvement in retinal innate defense against bacterial pathogens has not been investigated. In this article, we show that Muller cells express TLR2, a key sensor implicated in recognizing Gram-positive bacteria. We found that intravitreal injection of TLR2 agonist Pam3Cys and Staphylococcus aureus activated Muller glia in C57BL/6 mouse retina. Similarly, Pam3Cys or S. aureus elicited the expression of TLR2 and activated the NF-κB and p38 MAPK signaling cascade. Concomitant with the activation of signaling pathways, transcriptional expression and secretion of various proinflammatory cytokines (IL-6, TNF-α, and IL-1β), chemokines (IL-8), and antimicrobial peptide (LL-37) were also induced in Muller glia. Importantly, the culture media derived from TLR2-activated Muller glia exhibited robust bactericidal activity against S. aureus. Furthermore, use of neutralizing Ab, small interfering RNA, and pharmacological inhibitors revealed that Muller glial innate response to S. aureus is mediated via the TLR2-NF-κB axis. Collectively, this study for the first time, to our knowledge, establishes that the retinal Muller glia senses pathogens via TLR2 and contributes directly to retinal innate defense via production of inflammatory mediators and antimicrobial peptides.
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Affiliation(s)
- Nazeem Shamsuddin
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University, Detroit, MI 48201, USA
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Roy S, Sun Y, Pearlman E. Interferon-gamma-induced MD-2 protein expression and lipopolysaccharide (LPS) responsiveness in corneal epithelial cells is mediated by Janus tyrosine kinase-2 activation and direct binding of STAT1 protein to the MD-2 promoter. J Biol Chem 2011; 286:23753-62. [PMID: 21572044 DOI: 10.1074/jbc.m111.219345] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The inability of epithelial cells from the cornea and other tissues to respond to LPS is reportedly due to low expression of the TLR4 co-receptor MD-2. We generated MD-2(-/-) bone marrow chimeras, and showed that MD-2 expression on non-myeloid cells was sufficient to mediate LPS-induced corneal inflammation. As IFN-γ is produced during Pseudomonas aeruginosa corneal infection, we examined the role of this cytokine on MD-2 expression by primary human corneal epithelial (HCE) cells and HCE cell lines. Exogenous IFN-γ was found to induce MD-2 mRNA, MD-2 cell surface expression, and LPS responsiveness as determined by p65 translocation to the nucleus and production of IL-6, CXCL1, and CXCL8/IL-8. Incubation with either the AG490 JAK2 inhibitor or with STAT1 siRNA blocked STAT1 phosphorylation and MD-2 transcription. Furthermore, EMSA analysis demonstrated that STAT1 binds to the MD-2 promoter, indicating that STAT1 is an MD-2 transcription factor. Together, these findings demonstrate that IFN-γ induces MD-2 expression and LPS responsiveness in HCE cells by JAK-2-dependent STAT1 activation and direct binding to the MD-2 promoter. Furthermore, given our findings on LPS-induced corneal inflammation, it is likely that IFN-γ-induced MD-2 expression by corneal epithelial cells contributes to the host response in vivo, determining the extent of tissue damage and bacterial clearance.
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Affiliation(s)
- Sanhita Roy
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio 44095, USA
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Lugo-Villarino G, Hudrisier D, Tanne A, Neyrolles O. C-type lectins with a sweet spot for Mycobacterium tuberculosis. Eur J Microbiol Immunol (Bp) 2011; 1:25-40. [PMID: 24466434 PMCID: PMC3894812 DOI: 10.1556/eujmi.1.2011.1.6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The pattern of receptors sensing pathogens onto host cells is a key factor that can determine the outcome of the infection. This is particularly true when such receptors belong to the family of pattern recognition receptors involved in immunity. Mycobacterium tuberculosis, the etiologic agent of tuberculosis interacts with a wide range of pattern-recognition receptors present on phagocytes and belonging to the Toll-like, Nod-like, scavenger and C-type lectin receptor families. A complex scenario where those receptors can establish cross-talks in recognizing pathogens or microbial determinants including mycobacterial components in different spatial and temporal context starts to emerge as a key event in the outcome of the immune response, and thus, the control of the infection. In this review, we will focus our attention on the family of calcium-dependent carbohydrate receptors, the C-type lectin receptors, that is of growing importance in the context of microbial infections. Members of this family appear to be key innate immune receptors of mycobacteria, capable of cross-talk with other pattern recognition receptors to induce or modulate the inflammatory context upon mycobacterial infection.
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