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Nureen L, Biazik J, Carnell M, Di Girolamo N. A detailed survey of the murine limbus, its stem cell distribution, and its boundaries with the cornea and conjunctiva. Stem Cells Transl Med 2024:szae055. [PMID: 39077915 DOI: 10.1093/stcltm/szae055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 06/29/2024] [Indexed: 07/31/2024] Open
Abstract
The narrow intersection between the cornea and conjunctiva, otherwise known as the limbus, is purported to harbor stem cells (SCs) that replenish the ocular surface epithelium throughout life. Damage to this site or depletion of its SCs can have dire consequences for eye health and vision. To date, various SC and keratin proteins have been used to identify the limbus, however, none could definitively mark its boundaries. Herein, we use the mouse as a model system to investigate whether structural and phenotypic features can be used to define the limbus and its boundaries with adjacent tissues. We demonstrate that differentially aligned blood and lymphatic vessels, intraepithelial nerves, and basal epithelial cellular and nuclei dimensions can be used as structural landmarks of the limbus. Identification of these features enabled approximation of the limbal expanse, which varied across distinct ocular surface quadrants, with the superior nasal and inferior temporal limbus being the widest and narrowest, respectively. Moreover, label-retaining SCs were unevenly distributed across the ocular circumference, with increased numbers in the superior temporal and inferior temporal moieties. These findings will heighten our current understanding of the SC niche, be beneficial for accurately predicting SC distribution to improve their isolation and devising efficacious cell therapies, and importantly, aid the ongoing search for novel SC markers.
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Affiliation(s)
- Lamia Nureen
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
| | - Joanna Biazik
- Electron Microscope Unit, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Michael Carnell
- Katharina Gaus Light Microscopy Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Nick Di Girolamo
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
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Cheng KKW, Fingerhut L, Duncan S, Prajna NV, Rossi AG, Mills B. In vitro and ex vivo models of microbial keratitis: Present and future. Prog Retin Eye Res 2024; 102:101287. [PMID: 39004166 DOI: 10.1016/j.preteyeres.2024.101287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 07/09/2024] [Accepted: 07/10/2024] [Indexed: 07/16/2024]
Abstract
Microbial keratitis (MK) is an infection of the cornea, caused by bacteria, fungi, parasites, or viruses. MK leads to significant morbidity, being the fifth leading cause of blindness worldwide. There is an urgent requirement to better understand pathogenesis in order to develop novel diagnostic and therapeutic approaches to improve patient outcomes. Many in vitro, ex vivo and in vivo MK models have been developed and implemented to meet this aim. Here, we present current in vitro and ex vivo MK model systems, examining their varied design, outputs, reporting standards, and strengths and limitations. Major limitations include their relative simplicity and the perceived inability to study the immune response in these MK models, an aspect widely accepted to play a significant role in MK pathogenesis. Consequently, there remains a dependence on in vivo models to study this aspect of MK. However, looking to the future, we draw from the broader field of corneal disease modelling, which utilises, for example, three-dimensional co-culture models and dynamic environments observed in bioreactors and organ-on-a-chip scenarios. These remain unexplored in MK research, but incorporation of these approaches will offer further advances in the field of MK corneal modelling, in particular with the focus of incorporation of immune components which we anticipate will better recapitulate pathogenesis and yield novel findings, therefore contributing to the enhancement of MK outcomes.
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Affiliation(s)
- Kelvin Kah Wai Cheng
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - Leonie Fingerhut
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - Sheelagh Duncan
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - N Venkatesh Prajna
- Department of Cornea and Refractive Surgery Services, Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Madurai, Tamil Nadu, India
| | - Adriano G Rossi
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - Bethany Mills
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom.
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Di Girolamo N. Biologicals and Biomaterials for Corneal Regeneration and Vision Restoration in Limbal Stem Cell Deficiency. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2401763. [PMID: 38777343 DOI: 10.1002/adma.202401763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/15/2024] [Indexed: 05/25/2024]
Abstract
The mammalian cornea is decorated with stem cells bestowed with the life-long task of renewing the epithelium, provided they remain healthy, functional, and in sufficient numbers. If not, a debilitating disease known as limbal stem cell deficiency (LSCD) can develop causing blindness. Decades after the first stem cell (SC) therapy is devised to treat this condition, patients continue to suffer unacceptable failures. During this time, improvements to therapeutics have included identifying better markers to isolate robust SC populations and nurturing them on crudely modified biological or biomaterial scaffolds including human amniotic membrane, fibrin, and contact lenses, prior to their delivery. Researchers are now gathering information about the biomolecular and biomechanical properties of the corneal SC niche to decipher what biological and/or synthetic materials can be incorporated into these carriers. Advances in biomedical engineering including electrospinning and 3D bioprinting with surface functionalization and micropatterning, and self-assembly models, have generated a wealth of biocompatible, biodegradable, integrating scaffolds to choose from, some of which are being tested for their SC delivery capacity in the hope of improving clinical outcomes for patients with LSCD.
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Affiliation(s)
- Nick Di Girolamo
- Mechanisms of Disease and Translational Research, School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, 2052, Australia
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Alotaibi S, Papas E, Mobeen R, Ozkan J, Misra SL, Markoulli M. Tear film hTERT and corneal nerve characteristics in dry eye disease. Clin Exp Optom 2024:1-6. [PMID: 38755754 DOI: 10.1080/08164622.2024.2354775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 05/08/2024] [Indexed: 05/18/2024] Open
Abstract
CLINICAL RELEVANCE The behaviour of human telomerase reverse transcriptase (hTERT) in tears reflects its role in maintaining the ocular surface homoeostasis, as it is increased after the initial fitting of contact lenses and post-overnight lid closure. BACKGROUND hTERT has been shown to respond to cellular stress in neurodegenerative diseases and to enhance axonal regeneration after peripheral axotomy in an animal model. This work investigated whether the behaviour of hTERT in the tear film reflects ocular surface inflammation and neuronal changes in the presence of dry eye disease. METHODS Flush tears were collected from 18 participants with dry eye disease (14 females, 4 males, mean age 34.7 ± 5.2 years) and from 18 healthy participants without dry eye disease (8 females, 10 males, mean age 31.9 ± 5.8 years). Dry eye disease status was defined using the TFOS DEWS II diagnostic criteria. hTERT levels in tears were measured using enzyme-linked immunosorbent assays. Confocal images were taken at the level of the subbasal nerve plexus at the central cornea and at the inferior whorl, and the densities of corneal immune cells were evaluated as well as corneal nerve morphology metrics using a fully automated technique (University of Manchester, United Kingdom). RESULTS In participants with dry eye disease, hTERT levels were significantly higher compared to controls (median [interquartile range]: 434 [320-600] ng/ml, and 184 [42-390] ng/ml, respectively, p = 0.01). Increased nerve fibre width at the inferior whorl, was seen in those with dry eyes (0.0219 [0.0214-0.0236] mm/mm compared to controls 0.0217 [0.0207 0.0222] p < 0.001), but no significant differences were found in the density of corneal immune cells. CONCLUSIONS hTERT levels were elevated in participants with dry eye disease, and this was accompanied by increased nerve thickness in the inferior cornea. The hTERT response may reflect the stress induced to the ocular surface and corneal nerves due to having dry eye disease.
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Affiliation(s)
- Sultan Alotaibi
- Department of Optometry and Vision Science, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
| | - Eric Papas
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Rabia Mobeen
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Jerome Ozkan
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Stuti L Misra
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Maria Markoulli
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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Wu M, Zhang X, Karunaratne S, Lee JH, Lampugnani ER, Selva KJ, Chung AW, Mueller SN, Chinnery HR, Downie LE. Intravital Imaging of the Human Cornea Reveals the Differential Effects of Season on Innate and Adaptive Immune Cell Morphodynamics. Ophthalmology 2024:S0161-6420(24)00273-2. [PMID: 38703795 DOI: 10.1016/j.ophtha.2024.04.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 04/19/2024] [Accepted: 04/23/2024] [Indexed: 05/06/2024] Open
Abstract
PURPOSE Defining how the in vivo immune status of peripheral tissues is shaped by the external environment has remained a technical challenge. We recently developed Functional in vivo confocal microscopy (Fun-IVCM) for dynamic, longitudinal imaging of corneal immune cells in living humans. This study investigated the effect of seasonal-driven environmental factors on the morphodynamic features of human corneal immune cell subsets. DESIGN Longitudinal, observational clinical study. PARTICIPANTS Sixteen healthy participants (aged 18-40 years) attended 2 visits in distinct seasons in Melbourne, Australia (Visit 1, November-December 2021 [spring-summer]; Visit 2, April-June 2022 [autumn-winter]). METHODS Environmental data were collected over each period. Participants underwent ocular surface examinations and corneal Fun-IVCM (Heidelberg Engineering). Corneal scans were acquired at 5.5 ± 1.5-minute intervals for up to 5 time points. Time-lapse Fun-IVCM videos were created to analyze corneal immune cells, comprising epithelial T cells and dendritic cells (DCs), and stromal macrophages. Tear cytokines were analyzed using a multiplex bead-based immunoassay. MAIN OUTCOME MEASURES Difference in the density, morphology, and dynamic parameters of corneal immune cell subsets over the study periods. RESULTS Visit 1 was characterized by higher temperature, lower humidity, and higher air particulate and pollen levels compared with Visit 2. Clinical ocular surface parameters and the density of immune cell subsets were similar across visits. At Visit 1 , corneal epithelial DCs were larger, with a lower dendrite probing speed (0.38 ± 0.21 vs. 0.68 ± 0.33 μm/min; P < 0.001) relative to Visit 2; stromal macrophages were more circular and had less dynamic activity (Visit 1, 7.2 ± 1.9 vs. Visit 2, 10.3 ± 3.7 dancing index; P < 0.001). Corneal T cell morphodynamics were unchanged across periods. Basal tear levels of interleukin 2 and CXCL10 were relatively lower during spring-summer. CONCLUSIONS This study identifies that the in vivo morphodynamics of innate corneal immune cells (DCs, macrophages) are modified by environmental factors, but such effects are not evident for adaptive immune cells (T cells). The cornea is a potential in vivo window to investigate season-dependent environmental influences on the human immune system. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- Mengliang Wu
- Department of Optometry and Vision Sciences, The University of Melbourne, Carlton, Victoria, Australia; Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Xinyuan Zhang
- Department of Optometry and Vision Sciences, The University of Melbourne, Carlton, Victoria, Australia
| | - Senuri Karunaratne
- Department of Optometry and Vision Sciences, The University of Melbourne, Carlton, Victoria, Australia
| | - Ji-Hyun Lee
- Department of Optometry and Vision Sciences, The University of Melbourne, Carlton, Victoria, Australia
| | - Edwin R Lampugnani
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia; Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Kevin J Selva
- Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Amy W Chung
- Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Scott N Mueller
- Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, The University of Melbourne, Carlton, Victoria, Australia
| | - Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Carlton, Victoria, Australia.
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Chen M, Seo S, Simmons X, Maroud Y, Wong T, Schubert W, Yiu SC. Precise longitudinal monitoring of corneal change through in vivo confocal microscopy in a rat dry eye disease model. Mol Vis 2024; 30:150-159. [PMID: 39076769 PMCID: PMC11286106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 03/18/2024] [Indexed: 07/31/2024] Open
Abstract
Purpose While lacrimal gland removal is commonly used in animal models to replicate dry eye disease, research into systematically monitoring dry eye disease's longitudinal pathological changes is limited. In vivo confocal microscopy (Heidelberg Retina Tomograph 3 with a Rostock Cornea Module, Heidelberg Engineering Inc., Franklin, MA) can non-invasively reveal corneal histopathological structures. To monitor dry-eye-disease-related changes in corneal structures, we developed a precise monitoring method using in vivo confocal microscopy in a rat double lacrimal gland removal model. Methods Five Sprague-Dawley rats (age 8-9 weeks, male) underwent double lacrimal gland removal. Modified Schirmer's tear test, blink tests, and in vivo confocal microscopy images were acquired pre-surgery and at 1, 2, and 4 weeks post-surgery. Three individual stromal nerves were selected per eye as guide images, and images of the corresponding sub-basal nerve plexus area were acquired via volume acquisition. The same area was re-imaged in subsequent weeks. Results After double lacrimal gland removal, tear production was reduced by 60%, and the blink rate increased 10 times compared to pre-surgery. Starting from 1 week after surgery, in vivo confocal microscopy showed increased sub-basal nerve plexus nerve fiber density with inflammatory cell infiltration at the sub-basal nerve plexus layer and remained at an elevated level at 2 and 4 weeks post-surgery. Conclusions We demonstrated that our precise monitoring method revealed detailed changes in the corneal nerves, the epithelium, and the stroma.
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Affiliation(s)
- Minjie Chen
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Stefanie Seo
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Xianni Simmons
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Youssef Maroud
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Trystin Wong
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | | | - Samuel C Yiu
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
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Datta A, Lee JH, Truong T, Flandrin O, Yang Y, Evans DJ, Fleiszig SMJ. Persistence of Contact Lens-Induced Corneal Parainflammation Following Lens Removal. Invest Ophthalmol Vis Sci 2024; 65:8. [PMID: 38466283 DOI: 10.1167/iovs.65.3.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024] Open
Abstract
Purpose Contact lens wear induces corneal parainflammation involving increased immune cell numbers after 24 hours' (CD11c+, Lyz2+, γδ-T cells) and six days' (Ly6G+ cells) wear. We investigated the time course of onset and resolution of these responses. Methods LysMcre or C57BL/6J mice were fitted with a contact lens (four to 48 hours). Contralateral eyes did not wear lenses. After lens removal, Lyz2+, MHC-II+ or Ly6G+ cells were examined by quantitative imaging. RT-qPCR determined cytokine gene expression. Results Lens wear for 24 hours increased corneal Lyz2+ cells versus contralateral eyes approximately two-fold. Corneas remained free of visible pathology. The Lyz2+ response was not observed after four or 12 hours' wear, nor after 12 hours' wear plus 12 hours' no wear. Lens removal after 24 hours' wear further increased Lyz2+ cells (∼48% after one day), which persisted for four days, returning to baseline by seven days. Lyz2+ cells in contralateral eyes remained at baseline. MHC-II+ cells showed a similar response but without increasing after lens removal. Lens wear for 48 hours showed reduced Lyz2+ cells versus 24 hours' wear with one day discontinuation, correlating with reduced IL-1β and IL-18 gene expression. Lens wear for 24 hours did not induce Ly6G+ responses six days after removal. Conclusions Lens-induced corneal parainflammation involving Lyz2+ cells requires 24 hours' wear but persists after lens discontinuation, requiring seven days for reversal. Lens wear for 48 hours may suppress initial Lyz2+ cell and cytokine responses. The significance of parainflammation during and after lens wear remains to be determined.
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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
| | - Tiffany Truong
- 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
| | - Yujia Yang
- Herbert Wertheim School of Optometry & Vision Science, 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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Woronkowicz M, Roberts H, Skopiński P. The Role of Insulin-like Growth Factor (IGF) System in the Corneal Epithelium Homeostasis-From Limbal Epithelial Stem Cells to Therapeutic Applications. BIOLOGY 2024; 13:144. [PMID: 38534414 DOI: 10.3390/biology13030144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/18/2024] [Accepted: 02/19/2024] [Indexed: 03/28/2024]
Abstract
The corneal epithelium, comprising three layers of cells, represents the outermost portion of the eye and functions as a vital protective barrier while concurrently serving as a critical refractive structure. Maintaining its homeostasis involves a complex regenerative process facilitated by the functions of the lacrimal gland, tear film, and corneal nerves. Crucially, limbal epithelial stem cells located in the limbus (transitional zone between the cornea and the conjunctiva) are instrumental for the corneal epithelium integrity by replenishing and renewing cells. Re-epithelialization failure results in persistent defects, often associated with various ocular conditions including diabetic keratopathy. The insulin-like growth factor (IGF) system is a sophisticated network of insulin and other proteins essential for numerous physiological processes. This review examines its role in maintaining the corneal epithelium homeostasis, with a special focus on the interplay with corneal limbal stem cells and the potential therapeutic applications of the system components.
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Affiliation(s)
- Małgorzata Woronkowicz
- NDDH, Royal Devon University Healthcare NHS Foundation Trust, Barnstaple EX31 4JB, UK
- Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London EC1V 2PD, UK
| | - Harry Roberts
- West of England Eye Unit, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
- University of Exeter Medical School, Exeter EX1 2HZ, UK
| | - Piotr Skopiński
- Department of Ophthalmology, SPKSO Ophthalmic University Hospital, Medical University of Warsaw, 00-576 Warsaw, Poland
- Department of Histology and Embryology, Medical University of Warsaw, 02-004 Warsaw, Poland
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Asiedu K, Tummanapalli SS, Alotaibi S, Wang LL, Dhanapalaratnam R, Kwai N, Poynten A, Markoulli M, Krishnan AV. Impact of SGLT2 Inhibitors on Corneal Nerve Morphology and Dendritic Cell Density in Type 2 Diabetes. Ocul Immunol Inflamm 2024; 32:234-241. [PMID: 37801679 DOI: 10.1080/09273948.2023.2263789] [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: 08/29/2022] [Accepted: 09/22/2023] [Indexed: 10/08/2023]
Abstract
PURPOSE This study aims to determine the effects of SGLT2 inhibitors on corneal dendritic cell density and corneal nerve measures in type 2 diabetes. METHODS Corneal dendritic cell densities and nerve parameters were measured in people with type 2 diabetes treated with SGLT2 inhibitors (T2DM-SGLT2i) [n = 23] and those not treated with SGLT2 inhibitors (T2DM-no SGLT2i) [n = 23], along with 24 age and sex-matched healthy controls. RESULTS There was a reduction in all corneal nerve parameters in type 2 diabetes groups compared to healthy controls (All parameters: p < 0.05). No significant differences in corneal nerve parameters were observed between T2DM-SGLT2i and T2DM-no SGLT2i groups (All parameters: p > 0.05). Central corneal dendritic cells were significantly reduced [mature (p = 0.03), immature (p = 0.06) and total (p = 0.002)] in the T2DM-SGLT2i group compared to the T2DM-no SGLT2i group. Significantly, higher mature (p = 0.04), immature (p = 0.004), total (p = 0.002) dendritic cell densities in the T2DM-no SGLT2i group were observed compared to the healthy controls. In the inferior whorl, no significant difference in immature (p = 0.27) and total dendritic cell densities (p = 0.16) between T2DM-SGLT2i and T2DM-no SGLT2i were observed except mature dendritic cell density (p = 0.018). No differences in total dendritic cell density were observed in the central (p > 0.09) and inferior whorl (p = 0.88) between T2DM-SGLT2i and healthy controls. CONCLUSION The present study showed a reduced dendritic cell density in people with type 2 diabetes taking SGLT2 inhibitors compared to those not taking these medications.
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Affiliation(s)
- Kofi Asiedu
- School of Optometry & Vision Science, University of New South Wales, Sydney, Australia
| | | | - Sultan Alotaibi
- School of Optometry & Vision Science, University of New South Wales, Sydney, Australia
- Department of Optometry and Vision Science, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
| | - Leiao Leon Wang
- School of Clinical Medicine, University of New South Wales, Sydney, Australia
| | | | - Natalie Kwai
- School of Medical, Indigenous and Health Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia
| | - Ann Poynten
- Department of Endocrinology, Prince of Wales Hospital, Sydney, Australia
| | - Maria Markoulli
- School of Optometry & Vision Science, University of New South Wales, Sydney, Australia
| | - Arun V Krishnan
- School of Clinical Medicine, University of New South Wales, Sydney, Australia
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10
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Hong M, Chong SZ, Goh YY, Tong L. Two-Photon and Multiphoton Microscopy in Anterior Segment Diseases of the Eye. Int J Mol Sci 2024; 25:1670. [PMID: 38338948 PMCID: PMC10855705 DOI: 10.3390/ijms25031670] [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: 12/09/2023] [Revised: 01/19/2024] [Accepted: 01/23/2024] [Indexed: 02/12/2024] Open
Abstract
Two-photon excitation microscopy (TPM) and multiphoton fluorescence microscopy (MPM) are advanced forms of intravital high-resolution functional microscopy techniques that allow for the imaging of dynamic molecular processes and resolve features of the biological tissues of interest. Due to the cornea's optical properties and the uniquely accessible position of the globe, it is possible to image cells and tissues longitudinally to investigate ocular surface physiology and disease. MPM can also be used for the in vitro investigation of biological processes and drug kinetics in ocular tissues. In corneal immunology, performed via the use of TPM, cells thought to be intraepithelial dendritic cells are found to resemble tissue-resident memory T cells, and reporter mice with labeled plasmacytoid dendritic cells are imaged to understand the protective antiviral defenses of the eye. In mice with limbal progenitor cells labeled by reporters, the kinetics and localization of corneal epithelial replenishment are evaluated to advance stem cell biology. In studies of the conjunctiva and sclera, the use of such imaging together with second harmonic generation allows for the delineation of matrix wound healing, especially following glaucoma surgery. In conclusion, these imaging models play a pivotal role in the progress of ocular surface science and translational research.
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Affiliation(s)
- Merrelynn Hong
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore;
- Training and Education Department, Singapore National Eye Centre, Singapore 168751, Singapore
| | - Shu Zhen Chong
- Singapore Immunology Network (SIgN), Agency for Science Technology and Research (A*STAR), Singapore 138632, Singapore;
| | - Yun Yao Goh
- Lee Kong Chian School of Medicine, National Technical University, Singapore 639798, Singapore;
| | - Louis Tong
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore 168751, Singapore
- Ocular Surface Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Eye Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
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11
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Mobeen R, Stapleton F, Chao C, Huynh MC, Phoebe Wong YS, Naduvilath T, Golebiowski B. Epithelial Immune Cell Response to Initial Soft Contact Lens Wear in the Human Corneal and Conjunctival Epithelium. Invest Ophthalmol Vis Sci 2023; 64:18. [PMID: 38099736 PMCID: PMC10729840 DOI: 10.1167/iovs.64.15.18] [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: 08/21/2023] [Accepted: 11/19/2023] [Indexed: 12/18/2023] Open
Abstract
Purpose The purpose of this study was to assess the immediate ocular immune response to soft contact lens (CL) wear by examining presumed epithelial immune cell (EIC) density and morphology at the central, peripheral, limbal cornea, and conjunctiva. Methods Fifty-four participants naïve to CL wear (mean age = 24.8 ± 9.8 years, 44% female participants), were examined using in vivo confocal microscopy at baseline and after 2 hours of CL wear (1-Day ACUVUE MOIST). Images were captured at the central, temporal far peripheral and limbal cornea, and bulbar conjunctiva. EIC density was counted manually and morphology was graded. Differences in EIC parameters pre- and post-CL wear were examined using a generalized estimating equation model with appropriate post hoc analyses. Results After 2 hours of soft CL wear, there was a significant increase in EIC density in all regions other than the central cornea (all P < 0.001). Cell body size was significantly larger, and a higher proportion of participants exhibited EIC with long dendrites after lens wear at the central and peripheral cornea (both P < 0.001). There was a significant increase in the number of participants displaying EIC with thick dendrites at the peripheral (P = 0.04) and limbal cornea (P < 0.001) after lens wear. Conclusions EICs were primarily recruited to the peripheral regions, whereas the central cornea shows no significant recruitment after short-term CL wear. Both central and peripheral corneas exhibited an enhanced antigen capture capacity, whereas migratory capacity was increased in the peripheral corneal regions suggesting EIC activation following a short period of CL wear.
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Affiliation(s)
- Rabia Mobeen
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
| | - Fiona Stapleton
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
| | - Cecilia Chao
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
| | - Mandy C. Huynh
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
| | - Yee S. Phoebe Wong
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
| | - Thomas Naduvilath
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
- Brien Holden Vision Institute, University of New South Wales, New South Wales, Sydney, Australia
| | - Blanka Golebiowski
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
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12
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Nureen L, Di Girolamo N. Limbal Epithelial Stem Cells in the Diabetic Cornea. Cells 2023; 12:2458. [PMID: 37887302 PMCID: PMC10605319 DOI: 10.3390/cells12202458] [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: 08/24/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/28/2023] Open
Abstract
Continuous replenishment of the corneal epithelium is pivotal for maintaining optical transparency and achieving optimal visual perception. This dynamic process is driven by limbal epithelial stem cells (LESCs) located at the junction between the cornea and conjunctiva, which is otherwise known as the limbus. In patients afflicted with diabetes, hyperglycemia-induced impairments in corneal epithelial regeneration results in persistent epithelial and other defects on the ocular surface, termed diabetic keratopathy (DK), which progressively diminish vision and quality of life. Reports of delayed corneal wound healing and the reduced expression of putative stem cell markers in diabetic relative to healthy eyes suggest that the pathogenesis of DK may be associated with the abnormal activity of LESCs. However, the precise role of these cells in diabetic corneal disease is poorly understood and yet to be comprehensively explored. Herein, we review existing literature highlighting aberrant LESC activity in diabetes, focusing on factors that influence their form and function, and emerging therapies to correct these defects. The consequences of malfunctioning or depleted LESC stocks in DK and limbal stem cell deficiency (LSCD) are also discussed. These insights could be exploited to identify novel targets for improving the management of ocular surface complications that manifest in patients with diabetes.
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Affiliation(s)
| | - Nick Di Girolamo
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia;
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13
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Tajbakhsh Z, Golebiowski B, Stapleton F, Salouti R, Nowroozzadeh MH, Zamani M, Briggs N, Jalbert I. Dendritic Cell Density and Morphology Can Be Used to Differentiate Vernal Keratoconjunctivitis from Allergic Conjunctivitis. Biomolecules 2023; 13:1469. [PMID: 37892151 PMCID: PMC10605082 DOI: 10.3390/biom13101469] [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: 08/25/2023] [Revised: 09/22/2023] [Accepted: 09/26/2023] [Indexed: 10/29/2023] Open
Abstract
The aim of the study was to compare the distribution of corneal and conjunctival epithelial dendritic cells (DCs) in vernal keratoconjunctivitis (VKC), allergic conjunctivitis (AC), and non-allergic controls to examine if the allergy type causes differences in immune cell activation. The prospective study included 60 participants: 20 with VKC, 20 with AC, and 20 non-allergic controls. In vivo confocal microscopy was performed on the right eye. The locations scanned included the corneal centre, inferior whorl, corneal periphery, corneal limbus, and bulbar conjunctiva. The DCs were counted manually, and their morphology was assessed for the largest cell body size, the presence of dendrites, and the presence of long and thick dendrites. The DC density was higher in VKC and AC compared to non-allergic group at all locations (p ≤ 0.01) except at the inferior whorl. The DC density in VKC participants was significantly higher than in AC at the limbus (p < 0.001) but not at other locations. Both the AC and the VKC group had larger DC bodies at the corneal periphery and limbus compared to the non-allergic group (p ≤ 0.03). The study found a higher proportion of participants with DCs exhibiting long dendrites at both the corneal periphery in AC (p = 0.01) and at the corneal centre, periphery, and limbus in VKC, compared to the non-allergic group (p ≤ 0.001). In conclusion, a higher DC density at the limbus may be a marker of more severe VKC. DCs with larger cell bodies and a greater proportion of participants with DCs displaying long dendrites can be potential markers to differentiate allergy from non-allergy, and more severe forms of allergy from milder forms.
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Affiliation(s)
- Zahra Tajbakhsh
- School of Optometry and Vision Science, UNSW, Sydney, NSW 2052, Australia; (B.G.); (F.S.); (I.J.)
- Department of Optometry, School of Allied Health, University of Western Australia, Crawley, WA 6009, Australia
| | - Blanka Golebiowski
- School of Optometry and Vision Science, UNSW, Sydney, NSW 2052, Australia; (B.G.); (F.S.); (I.J.)
| | - Fiona Stapleton
- School of Optometry and Vision Science, UNSW, Sydney, NSW 2052, Australia; (B.G.); (F.S.); (I.J.)
| | - Ramin Salouti
- Salouti Cornea Research Center, Salouti Eye Clinic, Shiraz 71839-33636, Iran; (R.S.); (M.Z.)
- Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz 71348-14336, Iran;
| | - M. Hosein Nowroozzadeh
- Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz 71348-14336, Iran;
| | - Mohammad Zamani
- Salouti Cornea Research Center, Salouti Eye Clinic, Shiraz 71839-33636, Iran; (R.S.); (M.Z.)
| | - Nancy Briggs
- Stats Central, Mark Wainwright Analytical Centre, UNSW, Sydney, NSW 2052, Australia;
| | - Isabelle Jalbert
- School of Optometry and Vision Science, UNSW, Sydney, NSW 2052, Australia; (B.G.); (F.S.); (I.J.)
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