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Sun Z, Lu K, He Q, Tang Y, Li H, Pazo EE, Hu L, Wei R. INOS ablation promotes corneal wound healing via activation of Akt signaling. Exp Eye Res 2024; 243:109886. [PMID: 38583755 DOI: 10.1016/j.exer.2024.109886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/24/2024] [Accepted: 04/04/2024] [Indexed: 04/09/2024]
Abstract
Corneal injury leads to impaired normal structure of the cornea. Improving the wound healing process in epithelial cells significantly contributes to ocular damage treatments. Here, we aimed to investigate the potential mechanisms of nitric oxide (NO) and its mediator, inducible nitric oxide synthase (iNOS), in the process of corneal wound healing. We established a corneal injury model of iNOS-/- mice, and treated human corneal epithelial cell lines (HCE-2) with the iNOS inhibitor L-INL, with or without NO replenishment by supplying sodium nitroferricyanide dihydrate (SNP). Our findings showed that inhibition of NO/iNOS accelerated corneal repair, enhanced uPAR (a receptor protein indicating the migration ability), and improved epithelial cell migration. Furthermore, NO/iNOS ablation activated Akt phosphorylation, reduced neutrophil marker protein MPO expression, and downregulated the transcription of inflammation cytokines CXCL-1, CXCL-2, IL-1β, IL-6, and TNF-α. However, the protective effects of NO/iNOS inhibition are significantly reduced by NO replenishment when treated with SNP. Therefore, we confirmed that inhibiting NO/iNOS improved the corneal wound healing by facilitating epithelial cell migration and reducing inflammatory reactions, which might be related to the activation of the Akt signaling pathway.
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Affiliation(s)
- Ziwen Sun
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 300070, Tianjin, China
| | - Kunpeng Lu
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, 300070, Tianjin, China
| | - Qing He
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 300070, Tianjin, China
| | - Yang Tang
- Qingdao State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong Academy of Medical Sciences, 266071, Qingdao, China
| | - Haoru Li
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 300070, Tianjin, China
| | - Emmanuel Eric Pazo
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 300070, Tianjin, China
| | - Lizhi Hu
- Basic Medical College, Immunology Department, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Tianjin Medical University, Tianjin, 300070, China.
| | - Ruihua Wei
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 300070, Tianjin, China.
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2
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Labetoulle M, Baudouin C, Benitez Del Castillo JM, Rolando M, Rescigno M, Messmer EM, Aragona P. How gut microbiota may impact ocular surface homeostasis and related disorders. Prog Retin Eye Res 2024; 100:101250. [PMID: 38460758 DOI: 10.1016/j.preteyeres.2024.101250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 03/01/2024] [Accepted: 03/04/2024] [Indexed: 03/11/2024]
Abstract
Changes in the bacterial flora in the gut, also described as gut microbiota, are readily acknowledged to be associated with several systemic diseases, especially those with an inflammatory, neuronal, psychological or hormonal factor involved in the pathogenesis and/or the perception of the disease. Maintaining ocular surface homeostasis is also based on all these four factors, and there is accumulating evidence in the literature on the relationship between gut microbiota and ocular surface diseases. The mechanisms involved are mostly interconnected due to the interaction of central and peripheral neuronal networks, inflammatory effectors and the hormonal system. A better understanding of the influence of the gut microbiota on the maintenance of ocular surface homeostasis, and on the onset or persistence of ocular surface disorders could bring new insights and help elucidate the epidemiology and pathology of ocular surface dynamics in health and disease. Revealing the exact nature of these associations could be of paramount importance for developing a holistic approach using highly promising new therapeutic strategies targeting ocular surface diseases.
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Affiliation(s)
- Marc Labetoulle
- Ophthalmology Départment, Hopital Bicetre, APHP, Université Paris-Saclay, IDMIT Infrastructure, Fontenay-aux-Roses Cedex, France; Hôpital National de la Vision des Quinze, Vingts, IHU ForeSight, Paris Saclay University, Paris, France.
| | - Christophe Baudouin
- Hôpital National de la Vision des Quinze, Vingts, IHU ForeSight, Paris Saclay University, Paris, France
| | - Jose M Benitez Del Castillo
- Departamento de Oftalmología, Hospital Clínico San Carlos, Clínica Rementeria, Instituto Investigaciones Oftalmologicas Ramon Castroviejo, Universidad Complutense, Madrid, Spain
| | - Maurizio Rolando
- Ocular Surface and Dry Eye Center, ISPRE Ophthalmics, Genoa, Italy
| | - Maria Rescigno
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089, Milan, Italy; Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini, Pieve Emanuele, 20090, MI, Italy
| | | | - Pasquale Aragona
- Department of Biomedical Sciences, Ophthalmology Clinic, University of Messina, Messina, Italy
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3
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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.
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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
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4
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Datta A, Lee JH, Flandrin O, Horneman H, Lee J, Metruccio MME, Bautista D, Evans DJ, Fleiszig SMJ. TRPA1 and TPRV1 Ion Channels Are Required for Contact Lens-Induced Corneal Parainflammation and Can Modulate Levels of Resident Corneal Immune Cells. Invest Ophthalmol Vis Sci 2023; 64:21. [PMID: 37585189 PMCID: PMC10434714 DOI: 10.1167/iovs.64.11.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 07/17/2023] [Indexed: 08/17/2023] Open
Abstract
Purpose Contact lens wear can induce corneal parainflammation involving CD11c+ cell responses (24 hours), γδ T cell responses (24 hours and 6 days), and IL-17-dependent Ly6G+ cell responses (6 days). Topical antibiotics blocked these CD11c+ responses. Because corneal CD11c+ responses to bacteria require transient receptor potential (TRP) ion-channels (TRPA1/TRPV1), we determined if these channels mediate lens-induced corneal parainflammation. Methods Wild-type mice were fitted with contact lenses for 24 hours or 6 days and compared to lens wearing TRPA1 (-/-) or TRPV1 (-/-) mice or resiniferatoxin (RTX)-treated mice. Contralateral eyes were not fitted with lenses. Corneas were examined for major histocompatibility complex (MHC) class II+, CD45+, γδ T, or TNF-α+ cell responses (24 hours) or Ly6G+ responses (6 days) by quantitative imaging. The quantitative PCR (qPCR) determined cytokine gene expression. Results Lens-induced increases in MHC class II+ cells after 24 hours were abrogated in TRPV1 (-/-) but not TRPA1 (-/-) mice. Increases in CD45+ cells were unaffected. Increases in γδ T cells after 24 hours of wear were abrogated in TRPA1 (-/-) and TRPV1 (-/-) mice, as were 6 day Ly6G+ cell responses. Contralateral corneas of TRPA1 (-/-) and TRPV1 (-/-) mice showed reduced MHC class II+ and γδ T cells at 24 hours. RTX inhibited lens-induced parainflammatory phenotypes (24 hours and 6 days), blocked lens-induced TNF-α and IL-18 gene expression, TNF-α+ cell infiltration (24 hours), and reduced baseline MHC class II+ cells. Conclusions TRPA1 and TRPV1 mediate contact lens-induced corneal parainflammation after 24 hours and 6 days of wear and can modulate baseline levels of resident corneal immune cells.
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Affiliation(s)
- Ananya Datta
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, California, United States
| | - Ji Hyun Lee
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, California, United States
| | - Orneika Flandrin
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, California, United States
| | - Hart Horneman
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, California, United States
| | - Justin Lee
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, California, United States
| | - Matteo M E Metruccio
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, California, United States
| | - Diana Bautista
- Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States
| | - David J Evans
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, California, United States
- College of Pharmacy, Touro University California, Vallejo, California, United States
| | - Suzanne M J Fleiszig
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, California, United States
- Graduate groups in Vision Science, Microbiology, and Infectious Diseases & Immunity, University of California, Berkeley, California, United States
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5
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Hayashida A, Saeed HN, Zhang F, Song Y, Liu J, Parks WC, Bispo PJM, Park PW. Sulfated motifs in heparan sulfate inhibit Streptococcus pneumoniae adhesion onto fibronectin and attenuate corneal infection. PROTEOGLYCAN RESEARCH 2023; 1:e9. [PMID: 38957622 PMCID: PMC11218895 DOI: 10.1002/pgr2.9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 07/26/2023] [Indexed: 07/04/2024]
Abstract
A large number of bacterial pathogens bind to host extracellular matrix (ECM) components. For example, many Gram-negative and Gram-positive pathogens express binding proteins for fibronectin (FN) on their cell surface. Mutagenesis studies of bacterial FN-binding proteins have demonstrated their importance in pathogenesis in preclinical animal models. However, means to draw on these findings to design therapeutic approaches that specifically target FN-bacteria interactions have not been successful because bacterial pathogens can elaborate several FN-binding proteins and also because FN is an essential protein and likely a nondruggable target. Here we report that select heparan compounds potently inhibit Streptococcus pneumoniae infection of injured corneas in mice. Using intact heparan sulfate (HS) and heparin (HP), heparinase-digested fragments of HS, HP oligosaccharides, and chemically or chemoenzymatically modified heparan compounds, we found that inhibition of S. pneumoniae corneal infection by heparan compounds is not mediated by simple charge effects but by a selective sulfate group. Removal of 2-O-sulfates significantly inhibited the ability of HP to inhibit S. pneumoniae corneal infection, whereas the addition of 2-O-sulfates to heparosan (H) significantly increased H's ability to inhibit bacterial corneal infection. Proximity ligation assays indicated that S. pneumoniae attaches directly to FN fibrils in the corneal epithelial ECM and that HS and HP specifically inhibit this binding interaction in a 2-O-sulfate-dependent manner. These data suggest that heparan compounds containing 2-O-sulfate groups protect against S. pneumoniae corneal infection by inhibiting bacterial attachment to FN fibrils in the subepithelial ECM of injured corneas. Moreover, 2-O-sulfated heparan compounds significantly inhibited corneal infection in immunocompromised hosts, by a clinical keratitis isolate of S. pneumoniae, and also when topically administered in a therapeutic manner. These findings suggest that the administration of nonanticoagulant 2-O-sulfated heparan compounds may represent a plausible approach to the treatment of S. pneumoniae keratitis.
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Affiliation(s)
- Atsuko Hayashida
- Department of Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Hajirah N. Saeed
- Department of Ophthalmology, Boston Children’s Hospital, Boston, Massachusetts, USA
- Department of Ophthalmology, Massachusetts Eye and Ear, Boston, Massachusetts, USA
| | - Fuming Zhang
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Yuefan Song
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Jian Liu
- Division of Medicinal Chemistry, University of North Carolina, Chapel Hill, North Carolina, USA
| | - William C. Parks
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Paulo J. M. Bispo
- Department of Ophthalmology, Massachusetts Eye and Ear, Boston, Massachusetts, USA
| | - Pyong Woo Park
- Department of Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
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6
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Ji X, Jin P, Yu P, Wang P. Autophagy ameliorates Pseudomonas aeruginosa-infected diabetic wounds by regulating the toll-like receptor 4/myeloid differentiation factor 88 pathway. Wound Repair Regen 2023; 31:305-320. [PMID: 36879445 DOI: 10.1111/wrr.13074] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/11/2023] [Accepted: 02/18/2023] [Indexed: 03/08/2023]
Abstract
Diabetic foot ulcers (DFUs) are among the most common complications in patients with diabetes and a leading cause of lower extremity amputation. DFUs are exacerbated by prolonged bacterial infection; therefore, there is an urgent need for effective treatments to alleviate the burden associated with this condition. Although autophagy plays a unique role in pathogen phagocytosis and inflammation, its role in diabetic foot infections (DFIs) remains unclear. Pseudomonas aeruginosa (PA) is the most frequently isolated gram-negative bacterium from DFUs. Here, we evaluated the role of autophagy in ameliorating PA infection in wounds in a diabetic rat model and a bone marrow-derived macrophage (BMDM) hyperglycemia model. Both models were pretreated with or without rapamycin (RAPA) and then infected with or without PA. Pretreatment of rats with RAPA significantly enhanced PA phagocytosis, suppressed wound inflammation, reduced the M1:M2 macrophage ratio, and improved wound healing. In vitro investigation of the underlying mechanisms revealed that enhanced autophagy resulted in decreased macrophage secretion of inflammatory factors such as TNF-α, IL-6, and IL-1β but increased that of IL-10 in response to PA infection. Additionally, RAPA treatment significantly enhanced autophagy in macrophages by increasing LC3 and beclin-1 levels, which led to altered macrophage function. Furthermore, RAPA blocked the PA-induced TLR4/MyD88 pathway to regulate macrophage polarisation and inflammatory cytokine production, which was validated by RNA interference and use of the autophagy inhibitor 3-methyladenine (3-MA). These findings suggest enhancing autophagy as a novel therapeutic strategy against PA infection to ultimately improve diabetic wound healing.
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Affiliation(s)
- Xiaoyan Ji
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital &Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China.,Department of Emergency Ward, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| | - Peng Jin
- Department of Gastric Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China.,Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.,Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Pei Yu
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital &Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Penghua Wang
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital &Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
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7
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Datta A, Lee J, Truong T, Evans DJ, Fleiszig SMJ. Topical antibiotics reduce CD11c+ cell numbers in the healthy murine cornea and modulate their response to contact lens wear. Sci Rep 2022; 12:10655. [PMID: 35739166 PMCID: PMC9226138 DOI: 10.1038/s41598-022-14847-x] [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: 01/28/2022] [Accepted: 06/13/2022] [Indexed: 11/21/2022] Open
Abstract
Previously we reported contact lens-induced CD11c+ cell responses in healthy mouse corneas, a phenomenon that also occurs in humans. To test involvement of ocular-associated bacteria, the impact of topical antibiotics on corneal CD11c+ cell populations during 24 h of lens wear was examined. Corneas were treated with gentamicin and ofloxacin (0.3%) or gentamicin alone, some also treated prior to lens wear (24 h). Contralateral PBS-treated eyes served as controls. CD11c-YFP (Yellow Fluorescent Protein) mice allowed CD11c+ cell visualization. Viable bacteria, on the ocular surface or contact lens, were labeled using FISH (16S rRNA-targeted probe) or click-chemistry (alkDala). Antibiotic treatment reduced baseline CD11c+ cell numbers without lens wear and suppressed CD11c+ cell responses to lens wear if corneas were both pretreated and treated during wear. Few bacteria colonized corneas or lenses under any circumstances. Conjunctival commensals were significantly reduced by antibiotics with or without lens wear, but minimally impacted by lens wear alone. Deliberate inoculation with conjunctival commensals triggered CD11c+ cell responses irrespective of antibiotic pretreatment. These results suggest that while lens wear does not necessarily increase quantifiable numbers of conjunctival commensals, those neutralized by antibiotics play a role in lens-associated CD11c+ cell responses and maintaining baseline CD11c+ cell populations.
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Affiliation(s)
- Ananya Datta
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, CA, 94720, USA
| | - Justin Lee
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, CA, 94720, USA
| | - Tiffany Truong
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, CA, 94720, USA
| | - David J Evans
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, CA, 94720, USA.,College of Pharmacy, Touro University California, Vallejo, CA, USA
| | - Suzanne M J Fleiszig
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, CA, 94720, USA. .,Graduate Groups in Vision Science, Microbiology, and Infectious Diseases and Immunity, University of California, Berkeley, CA, USA.
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8
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Mahmud F, Roy R, Mohamed MF, Aboonabi A, Moric M, Ghoreishi K, Bayat M, Kuzel TM, Reiser J, Shafikhani SH. Therapeutic evaluation of immunomodulators in reducing surgical wound infection. FASEB J 2022; 36:e22090. [PMID: 34907595 PMCID: PMC9058973 DOI: 10.1096/fj.202101019r] [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: 06/21/2021] [Revised: 11/10/2021] [Accepted: 11/23/2021] [Indexed: 01/03/2023]
Abstract
Despite many advances in infection control practices, including prophylactic antibiotics, surgical site infections (SSIs) remain a significant cause of morbidity, prolonged hospitalization, and death worldwide. Our innate immune system possesses a multitude of powerful antimicrobial strategies which make it highly effective in combating bacterial, fungal, and viral infections. However, pathogens use various stealth mechanisms to avoid the innate immune system, which in turn buy them time to colonize wounds and damage tissues at surgical sites. We hypothesized that immunomodulators that can jumpstart and activate innate immune responses at surgical sites, would likely reduce infection at surgical sites. We used three immunomodulators; fMLP (formyl-Methionine-Lysine-Proline), CCL3 (MIP-1α), and LPS (Lipopolysaccharide), based on their documented ability to elicit strong inflammatory responses; in a surgical wound infection model with Pseudomonas aeruginosa to evaluate our hypothesis. Our data indicate that one-time topical treatment with these immunomodulators at low doses significantly increased proinflammatory responses in infected and uninfected surgical wounds and were as effective, (or even better), than a potent prophylactic antibiotic (Tobramycin) in reducing P. aeruginosa infection in wounds. Our data further show that immunomodulators did not have adverse effects on tissue repair and wound healing processes. Rather, they enhanced healing in both infected and uninfected wounds. Collectively, our data demonstrate that harnessing the power of the innate immune system by immunomodulators can significantly boost infection control and potentially stimulate healing. We propose that topical treatment with these immunomodulators at the time of surgery may have therapeutic potential in combating SSI, alone or in combination with prophylactic antibiotics.
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Affiliation(s)
- Foyez Mahmud
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA,Division of Hematology/Oncology/Cell Therapy, Rush University Medical Center, Chicago, IL, USA
| | - Ruchi Roy
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA,Division of Hematology/Oncology/Cell Therapy, Rush University Medical Center, Chicago, IL, USA
| | - Mohamed F. Mohamed
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA,Division of Hematology/Oncology/Cell Therapy, Rush University Medical Center, Chicago, IL, USA
| | - Anahita Aboonabi
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA,Division of Hematology/Oncology/Cell Therapy, Rush University Medical Center, Chicago, IL, USA
| | - Mario Moric
- Department of Anesthesiology, Rush University Medical Center, Chicago, IL, USA
| | | | - Mohammad Bayat
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Science, Tehran, Iran,Price Institute of Surgical Research, University of Louisville and Noveratech LLC. of Louisville, Louisville, KY, USA
| | - Timothy M. Kuzel
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA,Division of Hematology/Oncology/Cell Therapy, Rush University Medical Center, Chicago, IL, USA
| | - Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Sasha H. Shafikhani
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA,Division of Hematology/Oncology/Cell Therapy, Rush University Medical Center, Chicago, IL, USA,Cancer Center, Rush University Medical Center, Chicago, IL, USA,To whom correspondence should be addressed:
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9
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Wan SJ, Datta A, Flandrin O, Metruccio MME, Ma S, Nieto V, Kroken AR, Hill RZ, Bautista DM, Evans DJ, Fleiszig SMJ. Nerve-associated transient receptor potential ion channels can contribute to intrinsic resistance to bacterial adhesion in vivo. FASEB J 2021; 35:e21899. [PMID: 34569661 DOI: 10.1096/fj.202100874r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/05/2021] [Accepted: 08/18/2021] [Indexed: 12/15/2022]
Abstract
The cornea of the eye differs from other mucosal surfaces in that it lacks a viable bacterial microbiome and by its unusually high density of sensory nerve endings. Here, we explored the role of corneal nerves in preventing bacterial adhesion. Pharmacological and genetic methods were used to inhibit the function of corneal sensory nerves or their associated transient receptor potential cation channels TRPA1 and TRPV1. Impacts on bacterial adhesion, resident immune cells, and epithelial integrity were examined using fluorescent labeling and quantitative confocal imaging. TRPA1/TRPV1 double gene-knockout mice were more susceptible to adhesion of environmental bacteria and to that of deliberately-inoculated Pseudomonas aeruginosa. Supporting the involvement of TRPA1/TRPV1-expressing corneal nerves, P. aeruginosa adhesion was also promoted by treatment with bupivacaine, or ablation of TRPA1/TRPV1-expressing nerves using RTX. Moreover, TRPA1/TRPV1-dependent defense was abolished by enucleation which severs corneal nerves. High-resolution imaging showed normal corneal ultrastructure and surface-labeling by wheat-germ agglutinin for TRPA1/TRPV1 knockout murine corneas, and intact barrier function by absence of fluorescein staining. P. aeruginosa adhering to corneas after perturbation of nerve or TRPA1/TRPV1 function failed to penetrate the surface. Single gene-knockout mice showed roles for both TRPA1 and TRPV1, with TRPA1-/- more susceptible to P. aeruginosa adhesion while TRPV1-/- corneas instead accumulated environmental bacteria. Corneal CD45+/CD11c+ cell responses to P. aeruginosa challenge, previously shown to counter bacterial adhesion, also depended on TRPA1/TRPV1 and sensory nerves. Together, these results demonstrate roles for corneal nerves and TRPA1/TRPV1 in corneal resistance to bacterial adhesion in vivo and suggest that the mechanisms involve resident immune cell populations.
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Affiliation(s)
- Stephanie J Wan
- Vision Science Program, University of California, Berkeley, California, USA
| | - Ananya Datta
- School of Optometry, University of California, Berkeley, California, USA
| | - Orneika Flandrin
- Vision Science Program, University of California, Berkeley, California, USA
| | | | - Sophia Ma
- School of Optometry, University of California, Berkeley, California, USA
| | - Vincent Nieto
- School of Optometry, University of California, Berkeley, California, USA
| | - Abby R Kroken
- School of Optometry, University of California, Berkeley, California, USA
| | - Rose Z Hill
- Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, California, USA
| | - Diana M Bautista
- Department of Molecular and Cell Biology and Helen Wills Neuroscience Institute, University of California, Berkeley, California, USA
| | - David J Evans
- School of Optometry, University of California, Berkeley, California, USA.,College of Pharmacy, Touro University California, Vallejo, California, USA
| | - Suzanne M J Fleiszig
- Vision Science Program, University of California, Berkeley, California, USA.,School of Optometry, University of California, Berkeley, California, USA.,Graduate Groups in Microbiology and Infectious Diseases & Immunity, University of California, Berkeley, California, USA
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10
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Brothers KM, Harvey SAK, Shanks RMQ. Transcription Factor EepR Is Required for Serratia marcescens Host Proinflammatory Response by Corneal Epithelial Cells. Antibiotics (Basel) 2021; 10:antibiotics10070770. [PMID: 34202642 PMCID: PMC8300729 DOI: 10.3390/antibiotics10070770] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 11/24/2022] Open
Abstract
Relatively little is known about how the corneal epithelium responds to vision-threatening bacteria from the Enterobacterales order. This study investigates the impact of Serratia marcescens on corneal epithelial cell host responses. We also investigate the role of a bacterial transcription factor EepR, which is a positive regulator of S. marcescens secretion of cytotoxic proteases and a hemolytic surfactant. We treated transcriptomic and metabolomic analysis of human corneal limbal epithelial cells with wild-type bacterial secretomes. Our results show increased expression of proinflammatory and lipid signaling molecules, while this is greatly altered in eepR mutant-treated corneal cells. Together, these data support the model that the S. marcescens transcription factor EepR is a key regulator of host-pathogen interactions, and is necessary to induce proinflammatory chemokines, cytokines, and lipids.
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11
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Urwin L, Okurowska K, Crowther G, Roy S, Garg P, Karunakaran E, MacNeil S, Partridge LJ, Green LR, Monk PN. Corneal Infection Models: Tools to Investigate the Role of Biofilms in Bacterial Keratitis. Cells 2020; 9:E2450. [PMID: 33182687 PMCID: PMC7696224 DOI: 10.3390/cells9112450] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/06/2020] [Accepted: 11/07/2020] [Indexed: 12/15/2022] Open
Abstract
Bacterial keratitis is a corneal infection which may cause visual impairment or even loss of the infected eye. It remains a major cause of blindness in the developing world. Staphylococcus aureus and Pseudomonas aeruginosa are common causative agents and these bacterial species are known to colonise the corneal surface as biofilm populations. Biofilms are complex bacterial communities encased in an extracellular polymeric matrix and are notoriously difficult to eradicate once established. Biofilm bacteria exhibit different phenotypic characteristics from their planktonic counterparts, including an increased resistance to antibiotics and the host immune response. Therefore, understanding the role of biofilms will be essential in the development of new ophthalmic antimicrobials. A brief overview of biofilm-specific resistance mechanisms is provided, but this is a highly multifactorial and rapidly expanding field that warrants further research. Progression in this field is dependent on the development of suitable biofilm models that acknowledge the complexity of the ocular environment. Abiotic models of biofilm formation (where biofilms are studied on non-living surfaces) currently dominate the literature, but co-culture infection models are beginning to emerge. In vitro, ex vivo and in vivo corneal infection models have now been reported which use a variety of different experimental techniques and animal models. In this review, we will discuss existing corneal infection models and their application in the study of biofilms and host-pathogen interactions at the corneal surface.
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Affiliation(s)
- Lucy Urwin
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield S10 2RX, UK; (L.R.G.); (P.N.M.)
| | - Katarzyna Okurowska
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, UK; (K.O.); (G.C.); (E.K.)
- Sheffield Collaboratorium for Antimicrobial Resistance and Biofilms (SCARAB), University of Sheffield, Sheffield S1 3JD, UK; (S.M.); (L.J.P.)
| | - Grace Crowther
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, UK; (K.O.); (G.C.); (E.K.)
- Sheffield Collaboratorium for Antimicrobial Resistance and Biofilms (SCARAB), University of Sheffield, Sheffield S1 3JD, UK; (S.M.); (L.J.P.)
| | - Sanhita Roy
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (S.R.); (P.G.)
| | - Prashant Garg
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad 500034, India; (S.R.); (P.G.)
| | - Esther Karunakaran
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, UK; (K.O.); (G.C.); (E.K.)
- Sheffield Collaboratorium for Antimicrobial Resistance and Biofilms (SCARAB), University of Sheffield, Sheffield S1 3JD, UK; (S.M.); (L.J.P.)
| | - Sheila MacNeil
- Sheffield Collaboratorium for Antimicrobial Resistance and Biofilms (SCARAB), University of Sheffield, Sheffield S1 3JD, UK; (S.M.); (L.J.P.)
- Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, UK
| | - Lynda J. Partridge
- Sheffield Collaboratorium for Antimicrobial Resistance and Biofilms (SCARAB), University of Sheffield, Sheffield S1 3JD, UK; (S.M.); (L.J.P.)
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Luke R. Green
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield S10 2RX, UK; (L.R.G.); (P.N.M.)
| | - Peter N. Monk
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield S10 2RX, UK; (L.R.G.); (P.N.M.)
- Sheffield Collaboratorium for Antimicrobial Resistance and Biofilms (SCARAB), University of Sheffield, Sheffield S1 3JD, UK; (S.M.); (L.J.P.)
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12
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Pseudomonas aeruginosa Stimulates Inflammation and Enhances Kaposi's Sarcoma Herpesvirus-Induced Cell Proliferation and Cellular Transformation through both Lipopolysaccharide and Flagellin. mBio 2020; 11:mBio.02843-20. [PMID: 33173008 PMCID: PMC7667028 DOI: 10.1128/mbio.02843-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Inflammation triggered by innate immunity promotes carcinogenesis in cancer. Kaposi's sarcoma (KS), a hyperproliferative and inflammatory tumor caused by Kaposi's sarcoma-associated herpesvirus (KSHV) infection, is the most common cancer in AIDS patients. KSHV infection sensitizes cells to pathogen-associated molecular patterns (PAMPs). We examined the role of Pseudomonas aeruginosa, an opportunistic bacterium that can affect AIDS patients, in inflammation and cell proliferation of KSHV-transformed cells. P. aeruginosa stimulation increased cell proliferation and efficiency of colony formation in soft agar of KSHV-transformed rat primary mesenchymal precursor (KMM) cells but had no significant effect on the untransformed (MM) cells. P. aeruginosa stimulation also increased cell proliferation of KSHV-infected human B cells, BJAB, but not the uninfected cells. Mechanistically, P. aeruginosa stimulation resulted in increased inflammatory cytokines and activation of p38, ERK1/2, and JNK mitogen-activated protein kinase (MAPK) pathways in KMM cells while having no obvious effect on MM cells. P. aeruginosa induction of inflammation and MAPKs was observed with and without inhibition of the Toll-like receptor 4 (TLR4) pathway, while a flagellin-deleted mutant of P. aeruginosa required a functional TLR4 pathway to induce inflammation and MAPKs. Furthermore, treatment with either lipopolysaccharide (LPS) or flagellin alone was sufficient to induce inflammatory cytokines, activate MAPKs, and increase cell proliferation and efficiency of colony formation in soft agar of KMM cells. These results demonstrate that both LPS and flagellin are PAMPs that contribute to P. aeruginosa induction of inflammation in KSHV-transformed cells. Because AIDS-KS patients are susceptible to P. aeruginosa infection, our work highlights the preventive and therapeutic potential of targeting P. aeruginosa infection in these patients.IMPORTANCE Kaposi's sarcoma (KS), caused by infection with Kaposi's sarcoma-associated herpesvirus (KSHV), is one of the most common cancers in AIDS patients. KS is a highly inflammatory tumor, but how KSHV infection induces inflammation remains unclear. We have previously shown that KSHV infection upregulates Toll-like receptor 4 (TLR4), sensitizing cells to lipopolysaccharide (LPS) and Escherichia coli In the current study, we examined the role of Pseudomonas aeruginosa, an opportunistic bacterium that can affect AIDS patients, in inflammation and cell proliferation of KSHV-transformed cells. P. aeruginosa stimulation increased cell proliferation, inflammatory cytokines, and activation of growth and survival pathways in KSHV-transformed cells through two pathogen-associated molecular patterns, LPS and flagellin. Because AIDS-KS patients are susceptible to P. aeruginosa infection, our work highlights the preventive and therapeutic potential of targeting P. aeruginosa infection in these patients.
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13
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Colorado LH, Edwards K, Chinnery HR, Bazan HE. In vivo immune cell dynamics in the human cornea. Exp Eye Res 2020; 199:108168. [PMID: 32846151 DOI: 10.1016/j.exer.2020.108168] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/26/2020] [Accepted: 07/21/2020] [Indexed: 01/24/2023]
Abstract
In vivo confocal microscopy (IVCM) allows the evaluation of the living human cornea at the cellular level. The non-invasive nature of this technique longitudinal, repeated examinations of the same tissue over time. Image analysis of two-dimensional time-lapse sequences of presumed immune cells with and without visible dendrites at the corneal sub-basal nerve plexus in the eyes of healthy individuals was performed. We demonstrated evidence that cells without visible dendrites are highly dynamic and move rapidly in the axial directions. A number of dynamic cells were observed and measured from three eyes of different individuals. The total average displacement and trajectory speeds of three cells without visible dendrites (N = 9) was calculated to be 1.12 ± 0.21 and 1.35 ± 0.17 μm per minute, respectively. One cell with visible dendrites per cornea was also analysed. Tracking dendritic cell dynamics in vivo has the potential to significantly advance the understanding of the human immune adaptive and innate systems. The ability to observe and quantify migration rates of immune cells in vivo is likely to reveal previously unknown insights into corneal and general pathophysiology and may serve as an effective indicator of cellular responses to intervention therapies.
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Affiliation(s)
- Luisa H Colorado
- Institute of Health and Biomedical Innovation, School of Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, QLD, 4069, Australia.
| | - Katie Edwards
- Institute of Health and Biomedical Innovation, School of Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, QLD, 4069, Australia
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Haydee E Bazan
- Department of Ophthalmology and Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, 2020 Gravier St., Suite D, New Orleans, LA, 70112, USA
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14
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Wan SJ, Ma S, Evans DJ, Fleiszig SMJ. Resistance of the murine cornea to bacterial colonization during experimental dry eye. PLoS One 2020; 15:e0234013. [PMID: 32470039 PMCID: PMC7259750 DOI: 10.1371/journal.pone.0234013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 05/15/2020] [Indexed: 01/06/2023] Open
Abstract
The healthy cornea is remarkably resistant to infection, quickly clearing deliberately inoculated bacteria such as Pseudomonas aeruginosa and Staphylococcus aureus. Contrasting with the adjacent conjunctiva and other body surfaces, it also lacks a resident viable bacterial microbiome. Corneal resistance to microbes depends on intrinsic defenses involving tear fluid and the corneal epithelium. Dry eye, an ocular surface disease associated with discomfort and inflammation, can alter tear fluid composition and volume, and impact epithelial integrity. We previously showed that experimentally-induced dry eye (EDE) in mice does not increase corneal susceptibility to P. aeruginosa infection. Here, we explored if EDE alters corneal resistance to bacterial colonization. EDE was established in mice using scopolamine injections and dehumidified air-flow, and verified by phenol-red thread testing after 5 and 10 days. As expected, EDE corneas showed increased fluorescein staining versus controls consistent with compromised epithelial barrier function. Confocal imaging using mT/mG knock-in mice with red-fluorescent membranes revealed no other obvious morphological differences between EDE corneas and controls for epithelium, stroma, and endothelium. EDE corneas were imaged ex vivo and compared to controls after alkyne-functionalized D-alanine labeling of metabolically-active colonizing bacteria, or by FISH using a universal 16S rRNA gene probe. Both methods revealed very few viable bacteria on EDE corneas after 5 or 10 days (median of 0, upper quartile of ≤ 1 bacteria per field of view for each group [9–12 eyes per group]) similar to control corneas. Furthermore, there was no obvious difference in abundance of conjunctival bacteria, which included previously reported filamentous forms. Thus, despite reduced tear flow and apparent compromise to corneal barrier function (fluorescein staining), EDE murine corneas continue to resist bacterial colonization and maintain the absence of a resident viable bacterial microbiome.
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Affiliation(s)
- Stephanie J. Wan
- Vision Science Program, University of California, Berkeley, CA, United States of America
| | - Sophia Ma
- School of Optometry, University of California, Berkeley, CA, United States of America
| | - David J. Evans
- School of Optometry, University of California, Berkeley, CA, United States of America
- College of Pharmacy, Touro University California, Vallejo, CA, United States of America
| | - Suzanne M. J. Fleiszig
- Vision Science Program, University of California, Berkeley, CA, United States of America
- School of Optometry, University of California, Berkeley, CA, United States of America
- Graduate Groups in Microbiology, and Infectious Diseases & Immunity, University of California, Berkeley, CA, United States of America
- * E-mail:
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15
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Trujillo-Vargas CM, Schaefer L, Alam J, Pflugfelder SC, Britton RA, de Paiva CS. The gut-eye-lacrimal gland-microbiome axis in Sjögren Syndrome. Ocul Surf 2020; 18:335-344. [PMID: 31644955 PMCID: PMC7124975 DOI: 10.1016/j.jtos.2019.10.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/13/2019] [Accepted: 10/16/2019] [Indexed: 02/06/2023]
Abstract
The bacterial communities that collectively inhabit our body are called the microbiome. Virtually all body surface harbors bacteria. Recent advances in next-generation sequencing that have provided insight into the diversity, composition of bacterial communities, and their interaction are discussed in this review, as well as the current knowledge of how the microbiome promotes ocular health. The ocular surface is a site of low bacterial load. Sjögren Syndrome is an autoimmune disease that affects the exocrine glands, causing dry mouth and dry eye. Systemic antibiotic treatment and germ-free mice have demonstrated that commensal bacteria have a protective role for the ocular surface and lacrimal gland. The existence of a gut-eye-lacrimal gland axis-microbiome is discussed.
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Affiliation(s)
- Claudia M Trujillo-Vargas
- Grupo de Inmunodeficiencias Primarias, Facultad de Medicina, Universidad de Antioquia, UdeA, Medellin, Colombia; Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, USA.
| | - Laura Schaefer
- Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA.
| | - Jehan Alam
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, USA.
| | - Stephen C Pflugfelder
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, USA.
| | - Robert A Britton
- Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA.
| | - Cintia S de Paiva
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, USA.
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16
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Fleiszig SMJ, Kroken AR, Nieto V, Grosser MR, Wan SJ, Metruccio MME, Evans DJ. Contact lens-related corneal infection: Intrinsic resistance and its compromise. Prog Retin Eye Res 2019; 76:100804. [PMID: 31756497 DOI: 10.1016/j.preteyeres.2019.100804] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 11/05/2019] [Accepted: 11/12/2019] [Indexed: 12/20/2022]
Abstract
Contact lenses represent a widely utilized form of vision correction with more than 140 million wearers worldwide. Although generally well-tolerated, contact lenses can cause corneal infection (microbial keratitis), with an approximate annualized incidence ranging from ~2 to ~20 cases per 10,000 wearers, and sometimes resulting in permanent vision loss. Research suggests that the pathogenesis of contact lens-associated microbial keratitis is complex and multifactorial, likely requiring multiple conspiring factors that compromise the intrinsic resistance of a healthy cornea to infection. Here, we outline our perspective of the mechanisms by which contact lens wear sometimes renders the cornea susceptible to infection, focusing primarily on our own research efforts during the past three decades. This has included studies of host factors underlying the constitutive barrier function of the healthy cornea, its response to bacterial challenge when intrinsic resistance is not compromised, pathogen virulence mechanisms, and the effects of contact lens wear that alter the outcome of host-microbe interactions. For almost all of this work, we have utilized the bacterium Pseudomonas aeruginosa because it is the leading cause of lens-related microbial keratitis. While not yet common among corneal isolates, clinical isolates of P. aeruginosa have emerged that are resistant to virtually all currently available antibiotics, leading the United States CDC (Centers for Disease Control) to add P. aeruginosa to its list of most serious threats. Compounding this concern, the development of advanced contact lenses for biosensing and augmented reality, together with the escalating incidence of myopia, could portent an epidemic of vision-threatening corneal infections in the future. Thankfully, technological advances in genomics, proteomics, metabolomics and imaging combined with emerging models of contact lens-associated P. aeruginosa infection hold promise for solving the problem - and possibly life-threatening infections impacting other tissues.
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Affiliation(s)
- Suzanne M J Fleiszig
- School of Optometry, University of California, Berkeley, CA, USA; Graduate Group in Vision Science, University of California, Berkeley, CA, USA; Graduate Groups in Microbiology and Infectious Diseases & Immunity, University of California, Berkeley, CA, USA.
| | - Abby R Kroken
- School of Optometry, University of California, Berkeley, CA, USA
| | - Vincent Nieto
- School of Optometry, University of California, Berkeley, CA, USA
| | | | - Stephanie J Wan
- Graduate Group in Vision Science, University of California, Berkeley, CA, USA
| | | | - David J Evans
- School of Optometry, University of California, Berkeley, CA, USA; College of Pharmacy, Touro University California, Vallejo, CA, USA
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17
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A novel murine model for contact lens wear reveals clandestine IL-1R dependent corneal parainflammation and susceptibility to microbial keratitis upon inoculation with Pseudomonas aeruginosa. Ocul Surf 2018; 17:119-133. [PMID: 30439473 DOI: 10.1016/j.jtos.2018.11.006] [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: 07/12/2018] [Revised: 11/06/2018] [Accepted: 11/09/2018] [Indexed: 12/17/2022]
Abstract
PURPOSE Contact lens wear carries a risk of complications, including corneal infection. Solving these complications has been hindered by limitations of existing animal models. Here, we report development of a new murine model of contact lens wear. METHODS C57BL/6 mice were fitted with custom-made silicone-hydrogel contact lenses with or without prior inoculation with Pseudomonas aeruginosa (PAO1-GFP). Contralateral eyes served as controls. Corneas were monitored for pathology, and examined ex vivo using high-magnification, time-lapse imaging. Fluorescent reporter mice allowed visualization of host cell membranes and immune cells. Lens-colonizing bacteria were detected by viable counts and FISH. Direct-colony PCR was used for bacterial identification. RESULTS Without deliberate inoculation, lens-wearing corneas remained free of visible pathology, and retained a clarity similar to non-lens wearing controls. CD11c-YFP reporter mice revealed altered numbers, and distribution, of CD11c-positive cells in lens-wearing corneas after 24 h. Worn lenses showed bacterial colonization, primarily by known conjunctival or skin commensals. Corneal epithelial cells showed vacuolization during lens wear, and after 5 days, cells with phagocyte morphology appeared in the stroma that actively migrated over resident keratocytes that showed altered morphology. Immunofluorescence confirmed stromal Ly6G-positive cells after 5 days of lens wear, but not in MyD88 or IL-1R gene-knockout mice. P. aeruginosa-contaminated lenses caused infectious pathology in most mice from 1 to 13 days. CONCLUSIONS This murine model of contact lens wear appears to faithfully mimic events occurring during human lens wear, and could be valuable for experiments, not possible in humans, that help solve the pathogenesis of lens-related complications.
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18
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Wu YT, Truong TN, Tam C, Mendoza MN, Zhu L, Evans DJ, Fleiszig SMJ. Impact of topical corticosteroid pretreatment on susceptibility of the injured murine cornea to Pseudomonas aeruginosa colonization and infection. Exp Eye Res 2018; 179:1-7. [PMID: 30343040 DOI: 10.1016/j.exer.2018.10.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/04/2018] [Accepted: 10/17/2018] [Indexed: 10/28/2022]
Abstract
Research with animal models of Pseudomonas aeruginosa keratitis has shown that use of a topical corticosteroid alone against an established infection can significantly increase the number of colonizing bacteria or worsen clinical disease. Moreover, retrospective analysis has suggested that corticosteroid use in humans is associated with an increased risk of keratitis in eyes with pre-existing disease. Thus, while corticosteroids are often used to reduce ocular inflammation in the absence of infection, the risk of opportunistic infection remains a concern. However, the effect of corticosteroids on the intrinsic barrier function of uninfected corneas is unknown. Here, we tested if short-term topical corticosteroid treatment of an uninfected murine cornea would increase susceptibility to P. aeruginosa colonization or infection after epithelial injury. Topical prednisolone acetate (1%) was administered to one eye of C57BL/6 mice three times a day for 3 days; control eyes were treated with sterile PBS. Prior to inoculation with a cytotoxic P. aeruginosa corneal isolate strain 6206, corneas were subject to superficial-injury by tissue paper blotting, or scratch-injured followed by 12 h of healing. Previously we have shown that blotting renders mouse corneas susceptible to P. aeruginosa adhesion, but not infection, while 12 h healing reduces susceptibility to infection after scratching. Corneas were evaluated at 48 h for bacterial colonization and microbial keratitis (MK). To monitor impact on wound healing, corneal integrity was examined by fluorescein staining immediately after scarification and after 12 h healing. For both the tissue paper blotting and scratch-injury models, there was no significant difference in P. aeruginosa colonization at 48 h between corticosteroid-pretreated eyes and controls. With the blotting model, one case of MK was observed in a control (PBS-pretreated) cornea; none in corticosteroid-pretreated corneas. With the 12 h healing model, MK occurred in 6 of 17 corticosteroid-pretreated eyes versus 2 of 17 controls, a difference not statistically significant. Corticosteroid-pretreated eyes showed greater fluorescein staining 12 h after scarification injury, but this did not coincide with increased colonization or MK. Together, these data show that short-term topical corticosteroid therapy on an uninfected murine cornea does not necessarily enhance its susceptibility to P. aeruginosa colonization or infection after injury, even when it induces fluorescein staining.
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Affiliation(s)
- Yvonne T Wu
- School of Optometry, University of California, Berkeley, CA, USA
| | - Tan N Truong
- School of Optometry, University of California, Berkeley, CA, USA; Vision Science Program, University of California, Berkeley, CA, USA
| | - Connie Tam
- School of Optometry, University of California, Berkeley, CA, USA
| | - Myra N Mendoza
- School of Optometry, University of California, Berkeley, CA, USA
| | - Lucia Zhu
- School of Optometry, University of California, Berkeley, CA, USA
| | - David J Evans
- School of Optometry, University of California, Berkeley, CA, USA; College of Pharmacy, Touro University California, Vallejo, CA, USA
| | - Suzanne M J Fleiszig
- School of Optometry, University of California, Berkeley, CA, USA; Vision Science Program, University of California, Berkeley, CA, USA; Graduate Groups in Microbiology, And Infectious Diseases & Immunity, University of California, Berkeley, CA, USA.
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19
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Wan SJ, Sullivan AB, Shieh P, Metruccio MME, Evans DJ, Bertozzi CR, Fleiszig SMJ. IL-1R and MyD88 Contribute to the Absence of a Bacterial Microbiome on the Healthy Murine Cornea. Front Microbiol 2018; 9:1117. [PMID: 29896179 PMCID: PMC5986933 DOI: 10.3389/fmicb.2018.01117] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 05/11/2018] [Indexed: 01/09/2023] Open
Abstract
Microbial communities are important for the health of mucosal tissues. Traditional culture and gene sequencing have demonstrated bacterial populations on the conjunctiva. However, it remains unclear if the cornea, a transparent tissue critical for vision, also hosts a microbiome. Corneas of wild-type, IL-1R (-/-) and MyD88 (-/-) C57BL/6 mice were imaged after labeling with alkyne-functionalized D-alanine (alkDala), a probe that only incorporates into the peptidoglycan of metabolically active bacteria. Fluorescence in situ hybridization (FISH) was also used to detect viable bacteria. AlkDala labeling was rarely observed on healthy corneas. In contrast, adjacent conjunctivae harbored filamentous alkDala-positive forms, that also labeled with DMN-Tre, a Corynebacterineae-specific probe. FISH confirmed the absence of viable bacteria on healthy corneas, which also cleared deliberately inoculated bacteria within 24 h. Differing from wild-type, both IL-1R (-/-) and MyD88 (-/-) corneas harbored numerous alkDala-labeled bacteria, a result abrogated by topical antibiotics. IL-1R (-/-) corneas were impermeable to fluorescein suggesting that bacterial colonization did not reflect decreased epithelial integrity. Thus, in contrast to the conjunctiva and other mucosal surfaces, healthy murine corneas host very few viable bacteria, and this constitutive state requires the IL-1R and MyD88. While this study cannot exclude the presence of fungi, viruses, or non-viable or dormant bacteria, the data suggest that healthy murine corneas do not host a resident viable bacterial community, or microbiome, the absence of which could have important implications for understanding the homeostasis of this tissue.
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Affiliation(s)
- Stephanie J Wan
- Vision Science Program, University of California, Berkeley, Berkeley, CA, United States
| | - Aaron B Sullivan
- School of Optometry, University of California, Berkeley, Berkeley, CA, United States
| | - Peyton Shieh
- College of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Matteo M E Metruccio
- School of Optometry, University of California, Berkeley, Berkeley, CA, United States
| | - David J Evans
- School of Optometry, University of California, Berkeley, Berkeley, CA, United States
- College of Pharmacy, Touro University California, Vallejo, CA, United States
| | - Carolyn R Bertozzi
- School of Optometry, University of California, Berkeley, Berkeley, CA, United States
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, United States
| | - Suzanne M J Fleiszig
- School of Optometry, University of California, Berkeley, Berkeley, CA, United States
- Graduate Groups in Vision Sciences, Microbiology, and Infectious Diseases & Immunity, University of California, Berkeley, Berkeley, CA, United States
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