1
|
Alenezi H, Parnell G, Schibeci S, Ozkan J, Willcox M, White AJR, Carnt N. Ocular surface immune transcriptome and tear cytokines in corneal infection patients. Front Cell Infect Microbiol 2024; 14:1346821. [PMID: 38694515 PMCID: PMC11061372 DOI: 10.3389/fcimb.2024.1346821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/19/2024] [Indexed: 05/04/2024] Open
Abstract
Background Microbial keratitis is one of the leading causes of blindness globally. An overactive immune response during an infection can exacerbate damage, causing corneal opacities and vision loss. This study aimed to identify the differentially expressed genes between corneal infection patients and healthy volunteers within the cornea and conjunctiva and elucidate the contributing pathways to these conditions' pathogenesis. Moreover, it compared the corneal and conjunctival transcriptomes in corneal-infected patients to cytokine levels in tears. Methods Corneal and conjunctival swabs were collected from seven corneal infection patients and three healthy controls under topical anesthesia. RNA from seven corneal infection patients and three healthy volunteers were analyzed by RNA sequencing (RNA-Seq). Tear proteins were extracted from Schirmer strips via acetone precipitation from 38 cases of corneal infection and 14 healthy controls. The cytokines and chemokines IL-1β, IL-6, CXCL8 (IL-8), CX3CL1, IL-10, IL-12 (p70), IL-17A, and IL-23 were measured using an antibody bead assay. Results A total of 512 genes were found to be differentially expressed in infected corneas compared to healthy corneas, with 508 being upregulated and four downregulated (fold-change (FC) <-2 or > 2 and adjusted p <0.01). For the conjunctiva, 477 were upregulated, and 3 were downregulated (FC <-3 or ≥ 3 and adjusted p <0.01). There was a significant overlap in cornea and conjunctiva gene expression in patients with corneal infections. The genes were predominantly associated with immune response, regulation of angiogenesis, and apoptotic signaling pathways. The most highly upregulated gene was CXCL8 (which codes for IL-8 protein). In patients with corneal infections, the concentration of IL-8 protein in tears was relatively higher in patients compared to healthy controls but did not show statistical significance. Conclusions During corneal infection, many genes were upregulated, with most of them being associated with immune response, regulation of angiogenesis, and apoptotic signaling. The findings may facilitate the development of treatments for corneal infections that can dampen specific aspects of the immune response to reduce scarring and preserve sight.
Collapse
Affiliation(s)
- Heba Alenezi
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
- School of Optometry and Vision Science, The University of New South Wales, Sydney, NSW, Australia
- Centre for Vision Research, Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW, Australia
| | - Grant Parnell
- Centre for Immunology and Allergy Research, Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW, Australia
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Stephen Schibeci
- Centre for Immunology and Allergy Research, Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW, Australia
| | - Jerome Ozkan
- School of Optometry and Vision Science, The University of New South Wales, Sydney, NSW, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, The University of New South Wales, Sydney, NSW, Australia
| | - Andrew J. R. White
- School of Optometry and Vision Science, The University of New South Wales, Sydney, NSW, Australia
- Centre for Vision Research, Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW, Australia
| | - Nicole Carnt
- School of Optometry and Vision Science, The University of New South Wales, Sydney, NSW, Australia
- Centre for Vision Research, Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW, Australia
- Institute of Ophthalmology, University College London, London, United Kingdom
| |
Collapse
|
2
|
Konda N, Chakrabarti S, Garg P, Willcox MDP. Association of Single-Nucleotide Polymorphisms in Interleukin Genes with Microbial Keratitis in a South Indian Population. Pathogens 2022; 11:1387. [PMID: 36422638 PMCID: PMC9692714 DOI: 10.3390/pathogens11111387] [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] [Received: 10/25/2022] [Revised: 11/12/2022] [Accepted: 11/19/2022] [Indexed: 05/03/2024] Open
Abstract
BACKGROUND To examine the relationship between single-nucleotide polymorphisms (SNPs) in interleukin (IL) genes and keratitis and its clinical manifestations. METHODS SNPs in IL1B, IL6, CXCL8, IL10, and IL12B were analysed. Differences in frequencies of alleles, genotypes and haplotypes between cases and controls as well as associations between SNPs and clinical variables were calculated by χ2 tests with odds ratios. RESULTS The minor homologous genotype in IL1B rs16944 (p = 0.036; odds ratio (OR) = 2.063, 95% confidence interval (CI): 1.048-4.061) and CXCL8 rs4073 (p = 0.041; OR = 0.463, 95% CI: 0.224-0.956) and the heterologous genotypes in IL6 rs1800795 (p = 0.046; OR = 0.563, 95% CI: 0.326-0.972) and IL12B rs2569254 (p = 0.0446; OR = 0.557, 95% CI: 0.314-0.989) or rs730691 (p = 0.0051; OR = 0.451, 95% CI: 0.260-0.784) were associated with keratitis. The minor genotype of rs16944 was associated with severe infection (p = 0.046). The heterologous genotype in rs2569254 was associated with hospital admission, photophobia, and mode of contact lens wear (p ≤ 0.041). The heterologous genotype in rs730691 was associated with blurred vision, discharge, anterior chamber reaction, and mode of wear (p ≤ 0.047). CONCLUSIONS This study demonstrates that SNPs in IL1B and CXCL8 are associated with risk of developing keratitis. The study also found relationships between SNPs and clinical measures of keratitis. The potential for ethnic differences in frequency of SNPs and their association with keratitis should be followed up using different populations.
Collapse
Affiliation(s)
- Nagaraju Konda
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia
- Brien Holden Vision Institute, Sydney 2052, Australia
- School of Medical Sciences, University of Hyderabad, Hyderabad 500046, Telangana, India
| | - Subhabrata Chakrabarti
- Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Hyderabad 500034, Telangana, India
| | - Prashant Garg
- The Cornea Institute, L. V. Prasad Eye Institute, Hyderabad, Telangana 500034, India
| | - Mark D. P. Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia
| |
Collapse
|
3
|
Mursalin MH, Coburn PS, Miller FC, Livingston ET, Astley R, Callegan MC. C-X-C Chemokines Influence Intraocular Inflammation During Bacillus Endophthalmitis. Invest Ophthalmol Vis Sci 2021; 62:14. [PMID: 34784411 PMCID: PMC8606850 DOI: 10.1167/iovs.62.14.14] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Purpose The purpose of this study was to explore the C-X-C chemokines CXCL2 and CXCL10 as potential anti-inflammatory targets for Bacillus endophthalmitis. Methods Bacillus endophthalmitis was induced in C57BL/6J, CXCL2−/−, and CXCL10−/− mice. At specific times postinfection, eyes were analyzed for Bacillus, retinal function, and inflammation. The efficacies of intravitreal anti-CXCL2 and anti-CXCL10 with or without gatifloxacin in B. cereus endophthalmitis were also assessed using the same techniques. Results Despite similar Bacillus growth in eyes of C57BL/6J, CXCL2−/−, and CXCL10−/− mice, retinal function retention was greater in eyes of CXCL2−/− and CXCL10−/− mice compared to that of C57BL/6J mice. Neutrophil migration into eyes of CXCL2−/− and CXCL10−/− mice was reduced to a greater degree compared to that of eyes of C57BL/6J mice. Infected CXCL2−/− and CXCL10−/− mouse eyes had significantly less inflammation compared to that of C57BL/6J eyes. Retinal structures in infected eyes of CXCL2−/− mice were preserved for a longer time than in CXCL10−/− eyes. Compared to untreated eyes, there was less inflammation and significant retention of retinal function in eyes treated with anti-CXCL2 and anti-CXCL10 with or without gatifloxacin. Conclusions For Bacillus endophthalmitis, the absence of CXCL2 or CXCL10 in mice resulted in retained retinal function and less inflammation. The absence of CXCL2 led to a better clinical outcome than the absence of CXCL10. The use of anti-CXCL2 and anti-CXCL10 limited inflammation during B. cereus endophthalmitis. These results highlight the utility of CXCL2 and CXCL10 as potential targets for anti-inflammatory therapy that can be tested in conjunction with antibiotics for improving treating Bacillus endophthalmitis.
Collapse
Affiliation(s)
- Md Huzzatul Mursalin
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Phillip S Coburn
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States.,Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States
| | - Frederick C Miller
- Department of Cell Biology and Department of Family and Preventive Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Erin T Livingston
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Roger Astley
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States.,Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States
| | - Michelle C Callegan
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States.,Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States.,Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| |
Collapse
|
4
|
Lee JW, Somerville T, Kaye SB, Romano V. Staphylococcus aureus Keratitis: Incidence, Pathophysiology, Risk Factors and Novel Strategies for Treatment. J Clin Med 2021; 10:jcm10040758. [PMID: 33668633 PMCID: PMC7918096 DOI: 10.3390/jcm10040758] [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: 12/30/2020] [Revised: 02/09/2021] [Accepted: 02/09/2021] [Indexed: 02/07/2023] Open
Abstract
Bacterial keratitis is a devastating condition that can rapidly progress to serious complications if not treated promptly. Certain causative microorganisms such as Staphylococcus aureus and Pseudomonas aeruginosa are notorious for their resistance to antibiotics. Resistant bacterial keratitis results in poorer outcomes such as scarring and the need for surgical intervention. Thorough understanding of the causative pathogen and its virulence factors is vital for the discovery of novel treatments to avoid further antibiotic resistance. While much has been previously reported on P. aeruginosa, S. aureus has been less extensively studied. This review aims to give a brief overview of S. aureus epidemiology, pathophysiology and clinical characteristics as well as summarise the current evidence for potential novel therapies.
Collapse
Affiliation(s)
- Jason W. Lee
- School of Medicine, University of Liverpool, Liverpool L69 3GE, UK;
| | - Tobi Somerville
- Department of Eye and Vision Science, University of Liverpool, Liverpool L7 8TX, UK; (T.S.); (S.B.K.)
- St Paul’s Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK
| | - Stephen B. Kaye
- Department of Eye and Vision Science, University of Liverpool, Liverpool L7 8TX, UK; (T.S.); (S.B.K.)
- St Paul’s Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK
| | - Vito Romano
- Department of Eye and Vision Science, University of Liverpool, Liverpool L7 8TX, UK; (T.S.); (S.B.K.)
- St Paul’s Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK
- Correspondence:
| |
Collapse
|
5
|
Shrestha GS, Vijay AK, Stapleton F, Henriquez FL, Carnt N. Understanding clinical and immunological features associated with Pseudomonas and Staphylococcus keratitis. Cont Lens Anterior Eye 2020; 44:3-13. [PMID: 33303356 DOI: 10.1016/j.clae.2020.11.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/24/2020] [Accepted: 11/27/2020] [Indexed: 12/11/2022]
Abstract
Pseudomonas aeruginosa and Staphylococcus aureus are the two dominant Gram-negative and -positive species, respectively, isolated from patients with contact lens-related bacterial keratitis. The clinical features of bacterial keratitis vary, such that timely differential diagnosis can be challenging, which may cause a delay in diagnosis resulting in poorer outcome. This review aims to explore the current understanding of clinical and immunological features associated with contact lens-related P. aeruginosa and S. aureus keratitis based on currently available evidence. Firstly, the review characterises contact lens-related P. aeruginosa and S. aureus keratitis, based on clinical features and prognostic factors. Secondly, the review describes the primary immune response associated with a bacterial infection in in-vivo non-scratch contact lens-wearing animal models, colonised by bacteria on contact lens and topical administration of bacteria on the cornea. Finally, the review discusses the role of macrophage inflammatory protein-2 (MIP-2) and intercellular adhesion molecule (ICAM-1) in neutrophil recruitment based on both in-vivo scratch models of bacterial keratitis and bacterial challenged in cell culture models.
Collapse
Affiliation(s)
| | | | - Fiona Stapleton
- School of Optometry and Vision Science, UNSW Sydney, Australia
| | - Fiona L Henriquez
- School of Health and Life Sciences, The University of the West of Scotland, United Kingdom
| | - Nicole Carnt
- School of Optometry and Vision Science, UNSW Sydney, Australia; Westmead Institute for Medical Research, University of Sydney, Australia; Institute of Ophthalmology, University College London, United Kingdom
| |
Collapse
|
6
|
Diabetes-Mediated Toxicity Resulted in the Expression of CD80 and CD86 on Neutrophils after Delayed Wound Healing in Male Rats. BIOMED RESEARCH INTERNATIONAL 2020; 2020:3592425. [PMID: 32733939 PMCID: PMC7376395 DOI: 10.1155/2020/3592425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 01/15/2023]
Abstract
Background Polymorphonuclear neutrophils (PMNs) play an essential role in the innate immune response, and their number increases after prolonged inflammatory diabetic wounds and prolonged wounds in older rats. The expression of CD80 and CD86 on PMNs confirms their participation in acquired immunity, wherein these molecules are involved in antigen presentation. Materials and Methods We investigated CD80 and CD86 expression on PMNs by flow cytometry and analyzed the mRNA expression of neutrophil chemoattractants macrophage inflammatory protein-2 (MIP-2) and MIP-1α by real-time polymerase chain reaction (PCR) in diabetic wound, which was healed by a camel milk peptide (CMP). The animals were allocated to the following wounded groups: control, diabetic (DM), and diabetic treated with CMP (DM-CMP). Results Alkaline phosphatase, gamma-glutamyl transpeptidase, and lactate dehydrogenase levels were elevated in DM rats but decreased in peptide-treated rats. The expression of CD80 and CD86 was significantly higher in DM rats with prolonged wounds than in control rats. The expression of both markers was restored to normal levels in diabetic rats treated with CMP. RT-PCR analysis revealed the upregulation in MIP-2 mRNA expression in DM rats. However, neutrophil number at wounded sites of DM rats declined at day 1 after wounding as compared to that in control rats. MIP-2 mRNA expression and neutrophil number were restored in CMP-treated diabetic rats. Conclusion Prolonged wound stress induced toxicity in DM rats and significantly increased the expression of CD80 and CD86 on PMNs. CMP peptide ameliorated the levels of toxicity markers, CD80 and CD86, and chemoattractant molecules in diabetic rats.
Collapse
|
7
|
NLRP3 Inflammasome and Inflammatory Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:4063562. [PMID: 32148650 PMCID: PMC7049400 DOI: 10.1155/2020/4063562] [Citation(s) in RCA: 130] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/14/2020] [Accepted: 01/17/2020] [Indexed: 02/06/2023]
Abstract
Almost all human diseases are strongly associated with inflammation, and a deep understanding of the exact mechanism is helpful for treatment. The NLRP3 inflammasome composed of the NLRP3 protein, procaspase-1, and ASC plays a vital role in regulating inflammation. In this review, NLRP3 regulation and activation, its proinflammatory role in inflammatory diseases, interactions with autophagy, and targeted therapeutic approaches in inflammatory diseases will be summarized.
Collapse
|
8
|
Livingston ET, Mursalin MH, Callegan MC. A Pyrrhic Victory: The PMN Response to Ocular Bacterial Infections. Microorganisms 2019; 7:E537. [PMID: 31703354 PMCID: PMC6920826 DOI: 10.3390/microorganisms7110537] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/03/2019] [Accepted: 11/05/2019] [Indexed: 12/21/2022] Open
Abstract
Some tissues of the eye are susceptible to damage due to their exposure to the outside environment and inability to regenerate. Immune privilege, although beneficial to the eye in terms of homeostasis and protection, can be harmful when breached or when an aberrant response occurs in the face of challenge. In this review, we highlight the role of the PMN (polymorphonuclear leukocyte) in different bacterial ocular infections that invade the immune privileged eye at the anterior and posterior segments: keratitis, conjunctivitis, uveitis, and endophthalmitis. Interestingly, the PMN response from the host seems to be necessary for pathogen clearance in ocular disease, but the inflammatory response can also be detrimental to vision retention. This "Pyrrhic Victory" scenario is explored in each type of ocular infection, with details on PMN recruitment and response at the site of ocular infection. In addition, we emphasize the differences in PMN responses between each ocular disease and its most common corresponding bacterial pathogen. The in vitro and animal models used to identify PMN responses, such as recruitment, phagocytosis, degranulation, and NETosis, are also outlined in each ocular infection. This detailed study of the ocular acute immune response to infection could provide novel therapeutic strategies for blinding diseases, provide more general information on ocular PMN responses, and reveal areas of bacterial ocular infection research that lack PMN response studies.
Collapse
Affiliation(s)
- Erin T. Livingston
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (E.T.L.); (M.H.M.)
| | - Md Huzzatul Mursalin
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (E.T.L.); (M.H.M.)
| | - Michelle C. Callegan
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (E.T.L.); (M.H.M.)
- Department of Ophthalmology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Oklahoma Center for Neuroscience, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Dean McGee Eye Institute, Oklahoma City, OK 73104, USA
| |
Collapse
|
9
|
The Role of Connexin-43 in the Inflammatory Process: A New Potential Therapy to Influence Keratitis. J Ophthalmol 2019; 2019:9312827. [PMID: 30805212 PMCID: PMC6360563 DOI: 10.1155/2019/9312827] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 11/12/2018] [Accepted: 11/19/2018] [Indexed: 12/22/2022] Open
Abstract
The studies outlined in this review highlight the relationship between inflammatory signaling molecules and connexin-43 (Cx43). Gap junction (GJ) channels and hemichannels (HCs) participate in the metabolic activity between intra- and extracellular space. Some ions and small molecules are exchanged from cell to cell or cell to extracellular space to affect the process of inflammation via GJ. We analyzed the effects of signaling molecules, such as innate immunity messengers, transcription factors, LPS, cytokine, inflammatory chemokines, and MMPs, on Cx43 expression during the inflammatory process. At the same time, we found that these signaling molecules play a critical role in the pathogenesis of keratitis. Thus, we assessed the function of Cx43 during inflammatory corneal disease. Corneal healing plays an essential role in the late stage of keratitis. We found that Cx43 is involved in wound healing. Studies have shown that the decrease of Cx43 can decrease the time of healing. We also report several Cx43 mimic peptides which can inhibit the activity of Cx43 Hc to mediate the releasing of adenosine triphosphate (ATP), which may in turn influence the inflammatory process.
Collapse
|
10
|
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.
Collapse
Affiliation(s)
- Richard J O'Callaghan
- Department of Microbiology and Immunology, University of Mississippi Medical Center, 2500 N. State St., Jackson, MS 39216, USA.
| |
Collapse
|
11
|
Li D, Hodges RR, Bispo P, Gilmore MS, Gregory-Ksander M, Dartt DA. Neither non-toxigenic Staphylococcus aureus nor commensal S. epidermidi activates NLRP3 inflammasomes in human conjunctival goblet cells. BMJ Open Ophthalmol 2017; 2:e000101. [PMID: 29354725 PMCID: PMC5751869 DOI: 10.1136/bmjophth-2017-000101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 10/18/2017] [Accepted: 10/20/2017] [Indexed: 12/13/2022] Open
Abstract
Purpose The conjunctiva is a wet mucosal surface surrounding the cornea that is continuously exposed to pathogens. Nevertheless, persistent inflammation is not observed. We examined if the NOD-like receptor pyrin domain 3 (NLRP3) inflammasome functions as a sensor that distinguishes commensal and non-pathogenic bacteria from pathogenic bacteria in human conjunctival goblet cells. Methods Goblet cells were grown from human conjunctiva and co-cultured with commensal Staphylococcus epidermidis, isogenic non-toxigenic S. aureus ACL135 and as a control toxigenic S. aureus RN6390. Activation of the NLRP3 inflammasome was determined by measuring changes in NF-κB activity, expression of pro-interleukin (IL)-1β and NLRP3, activation of caspase-1 and secretion of mature IL-1β. Goblet cell mucin secretion was measured in parallel. Results While all three strains of bacteria were able to bind to goblet cells, neither commensal S. epidermidis nor isogenic non-toxigenic S. aureus ACL135 was able to stimulate an increase in (1) NF-κB activity, (2) pro-IL-1β and NLRP3 expression, (3) caspase-1 activation, (4) mature IL-1β and (5) mucin secretion. Toxigenic S. aureus, the positive control, increased these values: knockdown of NLRP3 with small interfering RNA (siRNA) completely abolished the toxigenic S. aureus-induced expression of pro-IL-1β and secretion of mature IL-1β. Conclusions We conclude that NLRP3 serves as a sensor capable of discriminating commensal and non-pathogenic bacteria from pathogenic bacteria in conjunctival goblet cells, and that activation of the NLRP3 inflammasome induced by pathogenic bacteria mediates secretion of both mature IL-1β and large secretory mucins from these cells.
Collapse
Affiliation(s)
- Dayu Li
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Robin R Hodges
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Paulo Bispo
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA.,Massachusetts Eye and Ear, Boston, Massachusetts, USA
| | - Michael S Gilmore
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA.,Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Meredith Gregory-Ksander
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Darlene A Dartt
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
12
|
Qin CC, Liu YN, Hu Y, Yang Y, Chen Z. Macrophage inflammatory protein-2 as mediator of inflammation in acute liver injury. World J Gastroenterol 2017; 23:3043-3052. [PMID: 28533661 PMCID: PMC5423041 DOI: 10.3748/wjg.v23.i17.3043] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 01/11/2017] [Accepted: 02/08/2017] [Indexed: 02/06/2023] Open
Abstract
Macrophage inflammatory protein (MIP)-2 is one of the CXC chemokines and is also known as chemokine CXC ligand (CXCL2). MIP-2 affects neutrophil recruitment and activation through the p38 mitogen-activated-protein-kinase-dependent signaling pathway, by binding to its specific receptors, CXCR1 and CXCR2. MIP-2 is produced by a variety of cell types, such as macrophages, monocytes, epithelial cells, and hepatocytes, in response to infection or injury. In liver injury, activated Kupffer cells are known as the major source of MIP-2. MIP-2-recruited and activated neutrophils can accelerate liver inflammation by releasing various inflammatory mediators. Here, we give a brief introduction to the basic molecular and cellular sources of MIP-2, and focus on its physiological and pathological functions in acute liver injury induced by concanavalin A, lipopolysaccharides, irradiation, ischemia/reperfusion, alcohol, and hypoxia, and hepatectomy-induced liver regeneration and tumor colorectal metastasis. Further understanding of the regulatory mechanisms of MIP-2 secretion and activation may be helpful to develop MIP-2-targeted therapeutic strategies to prevent liver inflammation.
Collapse
|