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Lian H, Fang X, Li Q, Liu S, Wei Q, Hua X, Li W, Liao C, Yuan X. NLRP3 Inflammasome-Mediated Pyroptosis Pathway Contributes to the Pathogenesis of Candida albicans Keratitis. Front Med (Lausanne) 2022; 9:845129. [PMID: 35463001 PMCID: PMC9020473 DOI: 10.3389/fmed.2022.845129] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/03/2022] [Indexed: 02/03/2023] Open
Abstract
Purpose Fungal keratitis is a sight-threatening corneal infection caused by fungal pathogens, and the pathogenic mechanisms have not been fully elucidated. The aim of this study was to determine whether NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated pyroptosis contributes to Candida albicans (C. albicans) keratitis and explore the underlying mechanism. Methods An in vivo mouse model of C. albicans keratitis and an in vitro culture model of human corneal epithelial cells (HCECs) challenged with heat-killed C. albicans (HKCA) were established in this study. The degree of corneal infection was evaluated by clinical scoring. Gene expression was assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis or immunofluorescence staining was performed to evaluate protein expression. TdT-mediated dUTP nick end labeling (TUNEL) staining was performed to examine the pyroptotic cell death. A lactate dehydrogenase (LDH) release assay was performed to assess cytotoxicity. Results Compared with the mock-infected group, we observed that the mRNA levels of NLRP3, caspase-1 (CASP1), interleukin (IL)−1β and gasdermin-D (GSDMD) in C. albicans-infected mice cornea was significantly increased. Our data also demonstrated that the protein expression of NLRP3 and the pyroptosis-related markers apoptosis-associated speck-like protein containing a CARD (ASC), cleaved CASP1, N-GSDMD, cleaved IL-1β and cleaved IL-18 as well as pyroptotic cell death were dramatically elevated in the mouse model of C. albicans keratitis. More importantly, NLRP3 knockdown markedly alleviated pyroptosis and consequently reduced corneal inflammatory reaction in C. albicans keratitis. In vitro, the presence of activated NLRP3 inflammasome and pyroptotic cell death were validated in HCECs exposed to HKCA. Furthermore, the potassium (K+) channel inhibitor glyburide decreased LDH release and suppressed NLRP3 inflammasome activation and pyroptosis in HCECs exposed to HKCA. Conclusion In conclusion, the current study revealed for the first time that NLRP3 inflammasome activation and pyroptosis occur in C. albicans-infected mouse corneas and HCECs. Moreover, NLRP3 inflammasome-mediated pyroptosis signaling is involved in the disease severity of C. albicans keratitis. Therefore, This NLRP3 inflammasome-dependent pathway may be an attractive target for the treatment of fungal keratitis.
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Affiliation(s)
- Huifang Lian
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.,Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin, China.,Department of Ophthalmology, Baoding First Central Hospital, Baoding, China.,State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - XiaoLong Fang
- Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin, China.,State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,The School of Medicine, Nankai University, Tianjin, China
| | - Qingyu Li
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.,Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin, China
| | - Shuang Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qiuhong Wei
- Department of Ophthalmology, Baoding First Central Hospital, Baoding, China
| | - Xia Hua
- Aier Eye Hospital, Tianjin, China
| | - Wenguang Li
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Chunyang Liao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Xiaoyong Yuan
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.,Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin, China.,The School of Medicine, Nankai University, Tianjin, China
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2
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Ahirwar LK, Sharma S. Elevated levels of interleukins, leukocyte protein and cathelicidin antimicrobial peptide are strongly associated with early to mid-stage of Pythium insidiosum infection in rabbit corneas. Curr Eye Res 2022; 47:677-687. [PMID: 35179411 DOI: 10.1080/02713683.2021.2023192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE Corneal infection in humans caused by Pythium insidiosum can lead to blindness and the host ocular immune response to it is less studied. Herein, we investigate the expression of mediators of innate and adaptive immune responses in a rabbit model. METHODS P. insidiosum zoospores were injected intracorneally in right eye of the nine New Zealand White rabbits while left eye was injected with 1XPBS. RT-qPCR and multiplex ELISA (mELISA) were used to study the expression of antimicrobial peptides (AMPs) and immune mediators in infected cornea on 3rd, 7th and 9th day of post-infection(PI). STRING-11.0 analysis was used to predict the interactions of immune mediators. mRNA expressions of pathogen recognition receptors (PRRs) were determined in human corneal epithelial cells (HCECs) stimulated with P. insidiosum zoospores. Data was analyzed using one-way ANOVA with Post-Hoc Tukey HSD test and p-value <0.05 was considered significant. RESULTS mRNA expression assay for IL-1β, IL-6, IL-8 and Cathelicidin antimicrobial peptide (CAP)-18 showed significant upregulation (p-value <0.05) on 7thday post-infection (PI) compared to 3rd and 9thday while Leukocyte protein (LeukoP) was elevated significantly on 3rd day followed by 7th and 9th day PI . Only IL-17A among other adaptive immune cytokines showed significant upregulation on 7thday compared to 9thday PI. Expressed in pg/mL, mELISA showed significant higher levels (p-value <0.05) of IL-1β, IL-8 in infected tissue in each of the time points compared to control. STRING analysis revealed co-expression of IL-1β, IL-8 and IL-6. Among PRRs, Dectin 1 and TLR4 showed significant upregulation in HCECs at 12hrs compared to 6hrs. CONCLUSION In the rabbit P. insidiosum keratitis model, innate immune mediators: IL-1β, IL-8, IL-6, AMPs: LeukoP and CAP-18 are strongly associated in early to mid-stage of corneal infection. Dectin 1 and TLR4 were observed to be associated with recognition of P. insidiosum.
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Affiliation(s)
- Lalit Kishore Ahirwar
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, L. V. Prasad Marg, Banjara Hills, Hyderabad-500034, India
| | - Savitri Sharma
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, L. V. Prasad Marg, Banjara Hills, Hyderabad-500034, India
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3
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Yong HM, Gour N, Sharma D, Khalil SM, Lane AP, Lajoie S. Epigenetic regulation of epithelial dectin-1 through an IL-33-STAT3 axis in allergic disease. Allergy 2022; 77:207-217. [PMID: 33982290 PMCID: PMC10580706 DOI: 10.1111/all.14898] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 04/10/2021] [Accepted: 04/14/2021] [Indexed: 12/15/2022]
Abstract
Allergic diseases arise in susceptible individuals in part because of decrements in protective pathways. The mechanism by which these anti-inflammatory molecules become repressed remains unclear. We have previously reported that epithelial dectin-1 prevents aberrant type 2 responses and is downregulated in the epithelium of allergic patients. Here, we report that dectin-1 is constitutively expressed by the respiratory epithelium in humans and that IL-33 specifically acts as a repressor of dectin-1. Mechanistically, this occurs via IL-33-dependent STAT3 activation and the subsequent repression of the dectin-1 gene, CLEC7A. We have identified a novel enhancer region upstream of the proximal promoter of CLEC7A that is only accessible in epithelial cells, but not in hematopoietic cells. Epigenetic repression of CLEC7A through this newly identified locus, downstream of an aberrant IL-33-STAT3 axis, occurs in the epithelium of allergic individuals. Collectively, our data identify a mechanism of epigenetic fine-tuning of dectin-1 expression in epithelial cells that may participate in allergenicity.
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Affiliation(s)
- Hwan Mee Yong
- Department of Otolaryngology, Johns Hopkins School of Medicine, Baltimore, MD
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Naina Gour
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD
| | - Deepika Sharma
- Department of Otolaryngology, Johns Hopkins School of Medicine, Baltimore, MD
| | - Syed Muaz Khalil
- Department of Otolaryngology, Johns Hopkins School of Medicine, Baltimore, MD
| | - Andrew P. Lane
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Stephane Lajoie
- Department of Otolaryngology, Johns Hopkins School of Medicine, Baltimore, MD
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
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4
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Argüeso P, Woodward AM, AbuSamra DB. The Epithelial Cell Glycocalyx in Ocular Surface Infection. Front Immunol 2021; 12:729260. [PMID: 34497615 PMCID: PMC8419333 DOI: 10.3389/fimmu.2021.729260] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/09/2021] [Indexed: 12/30/2022] Open
Abstract
The glycocalyx is the main component of the transcellular barrier located at the interface between the ocular surface epithelia and the external environment. This barrier extends up to 500 nm from the plasma membrane and projects into the tear fluid bathing the surface of the eye. Under homeostatic conditions, defense molecules in the glycocalyx, such as transmembrane mucins, resist infection. However, many pathogenic microorganisms have evolved to exploit components of the glycocalyx in order to gain access to epithelial cells and consequently exert deleterious effects. This manuscript reviews the implications of the ocular surface epithelial glycocalyx to bacterial, viral, fungal and parasitic infection. Moreover, it presents some ongoing controversies surrounding the functional relevance of the epithelial glycocalyx to ocular infectious disease.
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Affiliation(s)
- Pablo Argüeso
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, United States
| | - Ashley M Woodward
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, United States
| | - Dina B AbuSamra
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, United States
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5
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Cohen-Kedar S, Keizer D, Schwartz S, Rabinowitz KM, Kaboub K, Shaham Barda E, Sadot E, Wolff-Bar M, Shaltiel T, Dotan I. Commensal fungi and their cell-wall β-glucans direct differential responses in human intestinal epithelial cells. Eur J Immunol 2021; 51:864-878. [PMID: 33616974 DOI: 10.1002/eji.202048852] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/13/2020] [Accepted: 11/25/2020] [Indexed: 12/17/2022]
Abstract
Intestinal epithelial cells (IECs) are the first to encounter luminal antigens and play an active role in intestinal immune responses. We previously reported that β-glucans, major fungal cell-wall glycans, induced chemokine secretion by IEC lines in a Dectin-1- and Syk-dependent manner. Here, we show that in contrast to β-glucans, stimulation of IEC lines with Candida albicans and Saccharomyces cerevisiae did not induce secretion of any of the proinflammatory cytokines IL-8, CCL2, CXCL1, and GM-CSF. Commensal fungi and β-glucans activated Syk and ERK in IEC lines. However, only β-glucans activated p38, JNK, and the transcription factors NF-κB p65 and c-JUN, which were necessary for cytokine secretion. Furthermore, costimulation of IEC lines with β-glucans and C. albicans yielded decreased cytokine secretion compared to stimulation with β-glucans alone. Finally, ex vivo stimulation of human colonic mucosal explants with zymosan and C. albicans, leads to epithelial Syk and ERK phosphorylation, implying recognition of fungi and similar initial signaling pathways as in IEC lines. Lack of cytokine secretion in response to commensal fungi may reflect IECs' response to fungal glycans, other than β-glucans, that contribute to mucosal tolerance. Skewed epithelial response to commensal fungi may impair homeostasis and contribute to intestinal inflammation.
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Affiliation(s)
- Sarit Cohen-Kedar
- Division of Gastroenterology, Rabin Medical Center, Petah Tikva, Israel.,Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Danielle Keizer
- Division of Gastroenterology, Rabin Medical Center, Petah Tikva, Israel.,Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Suzana Schwartz
- Division of Gastroenterology, Rabin Medical Center, Petah Tikva, Israel.,Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Keren M Rabinowitz
- Division of Gastroenterology, Rabin Medical Center, Petah Tikva, Israel.,Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Kawsar Kaboub
- Division of Gastroenterology, Rabin Medical Center, Petah Tikva, Israel.,Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Efrat Shaham Barda
- Division of Gastroenterology, Rabin Medical Center, Petah Tikva, Israel.,Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Eran Sadot
- Department of Surgery, Beilinson Campus, Rabin Medical Center, Petah Tikva, Israel
| | - Meirav Wolff-Bar
- Department of Pathology, Beilinson Campus, Rabin Medical Center, Petah Tikva, Israel
| | - Tali Shaltiel
- Department of Surgery, Beilinson Campus, Rabin Medical Center, Petah Tikva, Israel
| | - Iris Dotan
- Division of Gastroenterology, Rabin Medical Center, Petah Tikva, Israel.,Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
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Dabrowski AN, Conrad C, Behrendt U, Shrivastav A, Baal N, Wienhold SM, Hackstein H, N'Guessan PD, Aly S, Reppe K, Suttorp N, Zahlten J. Peptidoglycan Recognition Protein 2 Regulates Neutrophil Recruitment Into the Lungs After Streptococcus pneumoniae Infection. Front Microbiol 2019; 10:199. [PMID: 30837960 PMCID: PMC6389715 DOI: 10.3389/fmicb.2019.00199] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 01/24/2019] [Indexed: 12/22/2022] Open
Abstract
Peptidoglycan (PGN) recognition proteins (PGLYRPs) are a highly conserved group of host defense proteins in insects and mammals that sense bacterial cell wall PGN and act bactericidally or cleave PGN by amidase function. Streptococcus (S.) pneumoniae is one of the top five killers worldwide and causes, e.g., pneumonia, endocarditis, meningitis and sepsis. S. pneumoniae accounts for approximately 1.5–2 million deaths every year. The risk of antibiotic resistance and a general poor prognosis in young children and elderly people have led to the need for new treatment approaches. To the best of our knowledge, there is no report on the relevance of PGLYRP2 in lung infections. Therefore, we infected mice deficient for PGLYRP2 transnasally with S. pneumoniae and examined the innate immune response in comparison to WT animals. As expected, PGLYRP2-KO animals had to be sacrificed earlier than their WT counterparts, and this was due to higher bacteremia. The higher bacterial load in the PGLYRP2-KO mice was accomplished with lower amounts of proinflammatory cytokines in the lungs. This led to an abolished recruitment of neutrophils into the lungs, the spread of bacteria and the subsequent aggravated course of the disease and early mortality of the PGLYRP2-KO mice. These data suggest a substantial role of PGLYRP2 in the early defense against S. pneumoniae infection, and PGLYRP2 might also affect other infections in the lungs.
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Affiliation(s)
- Alexander N Dabrowski
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Claudia Conrad
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Ulrike Behrendt
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Anshu Shrivastav
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Nelli Baal
- Immunology and Transfusion Medicine, Justus Liebig University Giessen, Giessen, Germany
| | - Sandra M Wienhold
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Division of Pulmonary Inflammation, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Holger Hackstein
- Immunology and Transfusion Medicine, Justus Liebig University Giessen, Giessen, Germany
| | - Philippe D N'Guessan
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Sahar Aly
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Katrin Reppe
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Division of Pulmonary Inflammation, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Norbert Suttorp
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Janine Zahlten
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
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7
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AbuSamra DB, Argüeso P. Lectin-Glycan Interactions in Corneal Infection and Inflammation. Front Immunol 2018; 9:2338. [PMID: 30349544 PMCID: PMC6186829 DOI: 10.3389/fimmu.2018.02338] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 09/20/2018] [Indexed: 11/13/2022] Open
Abstract
The cornea is an extraordinary component of vision that functions as the principal barrier to pathogens in the eye while allowing light transmission into the retina. Understanding the cellular and molecular mechanisms that maintain homeostasis in this tissue is the subject of intense scientific study given the high prevalence of corneal disease. Over the past decade, the interactions between lectins and glycans on plasma membranes have emerged as important regulatory factors in corneal biology. In particular, members of the galectin family have been shown to bind multiple β-galactoside-containing receptors to regulate immunopathological processes associated with viral and bacterial infection, transplantation, wound healing, dry eye, angiogenesis, and lymphangiogenesis. In this review, we describe the current understanding of how these surface interactions intersect with different pathways to activate unique cellular responses in cornea as well as their potential therapeutic implications.
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Affiliation(s)
- Dina B AbuSamra
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, United States
| | - Pablo Argüeso
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, United States
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8
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López-Muñoz A, Nicolás FE, García-Moreno D, Pérez-Oliva AB, Navarro-Mendoza MI, Hernández-Oñate MA, Herrera-Estrella A, Torres-Martínez S, Ruiz-Vázquez RM, Garre V, Mulero V. An Adult Zebrafish Model Reveals that Mucormycosis Induces Apoptosis of Infected Macrophages. Sci Rep 2018; 8:12802. [PMID: 30143654 PMCID: PMC6109148 DOI: 10.1038/s41598-018-30754-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 08/06/2018] [Indexed: 11/26/2022] Open
Abstract
Mucormycosis is a life-threatening fungal infection caused by various ubiquitous filamentous fungi of the Mucorales order, although Rhizopus spp. and Mucor spp. are the most prevalent causal agents. The limited therapeutic options available together with a rapid progression of the infection and a difficult early diagnosis produce high mortality. Here, we developed an adult zebrafish model of Mucor circinelloides infection which allowed us to confirm the link between sporangiospore size and virulence. Transcriptomic studies revealed a local, strong inflammatory response of the host elicited after sporangiospore germination and mycelial tissue invasion, while avirulent and UV-killed sporangiospores failed to induce inflammation and were rapidly cleared. Of the 857 genes modulated by the infection, those encoding cytokines, complement factors, peptidoglycan recognition proteins, and iron acquisition are particularly interesting. Furthermore, neutrophils and macrophages were similarly recruited independently of sporangiospore virulence and viability, which results in a robust depletion of both cell types in the hematopoietic compartment. Strikingly, our model also reveals for the first time the ability of mucormycosis to induce the apoptosis of recruited macrophages but not neutrophils. The induction of macrophage apoptosis, therefore, might represent a key virulence mechanism of these fungal pathogens, providing novel targets for therapeutic intervention in this lethal infection.
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Affiliation(s)
- Azucena López-Muñoz
- Department of Cell Biology and Histology, University of Murcia, IMIB-Arrixaca, 30100, Murcia, Spain
| | - Francisco E Nicolás
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100, Murcia, Spain
| | - Diana García-Moreno
- Department of Cell Biology and Histology, University of Murcia, IMIB-Arrixaca, 30100, Murcia, Spain
| | - Ana B Pérez-Oliva
- Department of Cell Biology and Histology, University of Murcia, IMIB-Arrixaca, 30100, Murcia, Spain
| | - María I Navarro-Mendoza
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100, Murcia, Spain
| | | | | | - Santiago Torres-Martínez
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100, Murcia, Spain
| | - Rosa M Ruiz-Vázquez
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100, Murcia, Spain
| | - Victoriano Garre
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100, Murcia, Spain.
| | - Victoriano Mulero
- Department of Cell Biology and Histology, University of Murcia, IMIB-Arrixaca, 30100, Murcia, Spain.
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9
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Zhao G, Hu M, Li C, Lee J, Yuan K, Zhu G, Che C. Osteopontin contributes to effective neutrophil recruitment, IL-1β production and apoptosis in Aspergillus fumigatus keratitis. Immunol Cell Biol 2018; 96:401-412. [PMID: 29359350 DOI: 10.1111/imcb.12010] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 12/14/2017] [Accepted: 01/17/2018] [Indexed: 12/13/2022]
Abstract
Fungal keratitis is a major cause of corneal ulcers, resulting in significant visual impairment and blindness. A phosphorylated glycoprotein secreted by immunocompetent cells, osteopontin (OPN) mediates cluster formation of the host fungal receptors and enhances the phagocytosis and clearance of pathogenic fungi. However, whether OPN production and function occurs in fungal keratitis is unknown. OPN expression in Aspergillus fumigatus keratitis patient corneas was assessed by quantitative polymerase chain reaction (qRT-PCR) and immunofluorescence. Human neutrophils, THP-1 macrophages and corneal epithelial cells (HCECs) stimulated with A. fumigatus were utilized for in vitro experiments. Mouse models of A. fumigatus keratitis were developed by intrastromal injection for in vivo experiments. Using siRNAs, neutralizing antibodies, recombinant proteins and inhibitors, the production and role of OPN in A. fumigatus infection was assessed by clinical evaluation, qRT-PCR, immunofluorescence, western blotting and bioluminescence image acquisition. We observed increased corneal OPN expression in A. fumigatus keratitis patients and mouse models compared to controls. OPN production in response to A. fumigatus infection was dependent on LOX-1 and Erk1/2. Compared to controls, OPN knockdown impaired proinflammatory cytokine IL-1β production, which was dependent on 4E-BP1. OPN knockdown decreased myeloperoxidase levels, and resulted in decreased neutrophil recruitment, higher fungal load and increased apoptosis in mouse A. fumigatus keratitis. Our results indicate that OPN is a critical component of the antifungal immune response and is essential for effective neutrophil recruitment, inflammatory cytokine production and apoptosis in A. fumigatus keratitis.
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Affiliation(s)
- Guiqiu Zhao
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Ming Hu
- Department of Basic Medical Sciences, Qingdao University, Qingdao, China
| | - Cui Li
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Jieun Lee
- Department of Ophthalmology, School of Medicine, Pusan National University, Yangsan, Korea
| | - Kelan Yuan
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Guoqiang Zhu
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Chengye Che
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, China
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10
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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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11
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Kolar SS, Baidouri H, McDermott AM. Role of Pattern Recognition Receptors in the Modulation of Antimicrobial Peptide Expression in the Corneal Epithelial Innate Response to F. solani. Invest Ophthalmol Vis Sci 2017; 58:2463-2472. [PMID: 28460048 PMCID: PMC5413214 DOI: 10.1167/iovs.16-20658] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose Fusarium solani (F. solani) keratitis is a potentially sight-threatening fungal infection of the cornea. Antimicrobial peptides (AMPs), such as human β-defensins (hBDs) and cathelicidins, essential components of the immune system, likely have a protective role against F. solani keratitis. We examined the role of pattern recognition receptors (PRRs), Dectin-1, and TLR2 in F. solani–induced modulation of AMP expression in vitro. Methods Human corneal epithelial cells (HCECs) were exposed to heat-inactivated F. solani or pathogen-associated molecular patterns (PAMPs) of F. solani (Zymosan or Zymosan Depleted) for 6, 12, or 24 hours following which AMP mRNA and protein levels were determined. Involvement of TLR2 and Dectin-1 was confirmed by using siRNA knock-down (TLR2 and Dectin-1) or chemical inhibitor BAY 61-3606 (Dectin-1). The functional significance of AMP upregulation was tested using culture supernatant from F. solani or PAMP-treated HCECs against F. solani in the presence of hBD2 or LL37 neutralizing antibody. Results We confirm that HCECs express Dectin-1 and TLR2. HCECs demonstrated upregulation of AMPs hBD2 and cathelicidin LL37 following exposure to heat-inactivated F. solani or PAMPs. TLR2 and Dectin-1 knockdown and BAY 61-3606 treatment decreased AMP mRNA upregulation confirming PRR involvement. The culture supernatant from F. solani or PAMP-treated HCECs showed substantial killing of F. solani and hBD2 or LL37 neutralizing antibody significantly decreased this effect implicating involvement of these AMPs. Conclusions These findings demonstrate that Dectin-1 and TLR2 have an important role in regulating F. solani-induced AMP expression in corneal epithelial cells.
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Affiliation(s)
- Satya Sree Kolar
- The Ocular Surface Institute, University of Houston, College of Optometry, Houston, Texas, United States
| | - Hasna Baidouri
- The Ocular Surface Institute, University of Houston, College of Optometry, Houston, Texas, United States
| | - Alison M McDermott
- The Ocular Surface Institute, University of Houston, College of Optometry, Houston, Texas, United States
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Chi W, Hua X, Chen X, Bian F, Yuan X, Zhang L, Wang X, Chen D, Deng R, Li Z, Liu Y, de Paiva CS, Pflugfelder SC, Li DQ. Mitochondrial DNA oxidation induces imbalanced activity of NLRP3/NLRP6 inflammasomes by activation of caspase-8 and BRCC36 in dry eye. J Autoimmun 2017; 80:65-76. [PMID: 28238526 DOI: 10.1016/j.jaut.2017.02.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/19/2016] [Accepted: 02/14/2017] [Indexed: 12/27/2022]
Abstract
The concept of innate immunity has been expanded to recognize environmental pathogens other than microbial components. However, whether and how the innate immunity is initiated by epithelium in response to environmental physical challenges such as low humidity and high osmolarity in an autoimmune disease, dry eye, is still largely unknown. Using two experimental dry eye models, primary human corneal epithelial cultures exposed to hyperosmolarity and mouse ocular surface facing desiccating stress, we uncovered novel innate immunity pathway by ocular surface epithelium, where oxidized mitochondrial DNA induces imbalanced activation of NLRP3/NLRP6 inflammasomes via stimulation of caspase-8 and BRCC36 in response to environmental stress. Activated NLRP3 with suppressed NLRP6 stimulates caspase-1 activation that leads to IL-1β and IL-18 maturation and secretion. NLRP3-independent caspase-8 noncanonically activates caspase-1 via reciprocal regulation of NLRP3/NLRP6-mediated inflammasomes. Reactive oxygen species-induced mitochondrial DNA oxidative damage and BRCC36 deubiquitinating activity provide a missing link and mechanism by which innate immunity responds to environmental stress via caspase-8-involved NLRP3/NLRP6 inflammasomes.
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Affiliation(s)
- Wei Chi
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China; Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.
| | - Xia Hua
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA; Second Hospital of Tianjin Medical University, Tianjin, China.
| | - Xin Chen
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA; School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China.
| | - Fang Bian
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.
| | - Xiaoyong Yuan
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.
| | - Lili Zhang
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Xiaoran Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China; Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.
| | - Ding Chen
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA; School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China.
| | - Ruzhi Deng
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA; School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China.
| | - Zhijie Li
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
| | - Cintia S de Paiva
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.
| | - Stephen C Pflugfelder
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.
| | - De-Quan Li
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.
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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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14
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Stepp MA, Tadvalkar G, Hakh R, Pal-Ghosh S. Corneal epithelial cells function as surrogate Schwann cells for their sensory nerves. Glia 2016; 65:851-863. [PMID: 27878997 DOI: 10.1002/glia.23102] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 10/30/2016] [Accepted: 11/02/2016] [Indexed: 12/13/2022]
Abstract
The eye is innervated by neurons derived from both the central nervous system and peripheral nervous system (PNS). While much is known about retinal neurobiology and phototransduction, less attention has been paid to the innervation of the eye by the PNS and the roles it plays in maintaining a functioning visual system. The ophthalmic branch of the trigeminal ganglion contains somas of neurons that innervate the cornea. These nerves provide sensory functions for the cornea and are referred to as intraepithelial corneal nerves (ICNs) consisting of subbasal nerves and their associated intraepithelial nerve terminals. ICNs project for several millimeters within the corneal epithelium without Schwann cell support. Here, we present evidence for the hypothesis that corneal epithelial cells function as glial cells to support the ICNs. Much of the data supporting this hypothesis is derived from studies of corneal development and the reinnervation of the ICNs in the rodent and rabbit cornea after superficial wounds. Corneal epithelial cells activate in response to injury via mechanisms similar to those induced in Schwann cells during Wallerian Degeneration. Corneal epithelial cells phagocytize distal axon fragments within hours of ICN crush wounds. During aging, the proteins, lipids, and mitochondria within the ICNs become damaged in a process exacerbated by UV light. We propose that ICNs shed their aged and damaged termini and continuously elongate to maintain their density. Available evidence points to new unexpected roles for corneal epithelial cells functioning as surrogate Schwann cells for the ICNs during homeostasis and in response to injury. GLIA 2017;65:851-863.
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Affiliation(s)
- Mary Ann Stepp
- Department of Anatomy and Regenerative Biology, George Washington University Medical School, Washington, DC
| | - Gauri Tadvalkar
- Department of Anatomy and Regenerative Biology, George Washington University Medical School, Washington, DC
| | - Raymond Hakh
- Department of Anatomy and Regenerative Biology, George Washington University Medical School, Washington, DC
| | - Sonali Pal-Ghosh
- Department of Anatomy and Regenerative Biology, George Washington University Medical School, Washington, DC
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