Cornea

Cornea Publications

Wittmann J, Dieckow J, Schröder H, Hampel U, Garreis F, Jacobi C, Milczarek A, Hsieh KL, Pulli B, Chen JW, Hoogeboom S, Bräuer L, Paulsen FP, Schob S, Schicht M. Plasma gelsolin promotes re-epithelialization. Sci Rep 2018;8(1):13140.Abstract
Woundhealing disorders characterized by impaired or delayed re-epithelialization are a serious medical problem that is painful and difficult to treat. Gelsolin (GSN), a known actin modulator, supports epithelial cell regeneration and apoptosis. The aim of this study was to estimate the potential of recombinant gelsolin (rhu-pGSN) for ocular surface regeneration to establish a novel therapy for delayed or complicated wound healing. We analyzed the influence of gelsolin on cell proliferation and wound healing in vitro, in vivo/ex vivo and by gene knockdown. Gelsolin is expressed in all tested tissues of the ocular system as shown by molecular analysis. The concentration of GSN is significantly increased in tear fluid samples of patients with dry eye disease. rhu-pGSN induces cell proliferation and faster wound healing in vitro as well as in vivo/ex vivo. TGF-β dependent transcription of SMA is significantly decreased after GSN gene knockdown. Gelsolin is an inherent protein of the ocular system and is secreted into the tear fluid. Our results show a positive effect on corneal cell proliferation and wound healing. Furthermore, GSN regulates the synthesis of SMA in myofibroblasts, which establishes GSN as a key protein of TGF-β dependent cell differentiation.
Yazdani M, Chen X, Tashbayev B, Utheim ØA, Ræder S, Lagli N, Stojanovic A, Dartt DA, Utheim TP. Tear Production Levels and Dry Eye Disease Severity in a Large Norwegian Cohort. Curr Eye Res 2018;:1-6.Abstract
PURPOSE: To determine if the Schirmer I test (without anesthesia) cut-off value is a predictor of dry eye severity in a large Norwegian cohort of dry eye disease (DED) patients, which are grouped into six levels of tear production. METHODS: Patients (n = 1090) with DED of different etiologies received an extensive dry eye work-up: osmolarity (Osm), tear meniscus height (TMH), tear film break-up time (TFBUT), ocular protection index (OPI), ocular surface staining (OSS), Schirmer I test (ST), meibum expressibility (ME), and meibum quality (MQ). Classification of dry eye severity level (DESL) and diagnosis of meibomian gland dysfunction (MGD) were also included. The cohort was divided into six groups: below and above cut-off values of 5 (groups 1 and 2), 10 (groups 3 and 4), and 15 mm (groups 5 and 6) of ST. Mann-Whitney test and Chi-Square test were used for group comparison of parameters (p ≤ 0.05). RESULTS: The groups 1, 3, and 5 had values indicating more severe DED than the groups 2, 4, 6 with significant difference in DESL, Osm, TFBUT, OPI, OSS, and TMH. Regardless of the choice of cut-off values, there was no statistically significant difference in ME, MQ, and MGD between groups below and above selected cut-off value. When gender difference was considered in each group, significant difference was only observed for DESL (groups 2, 4, and 5), TFBUT (groups 2, 4, and 5), OPI (groups 2 and 6), and ME (group1). CONCLUSIONS: Schirmer I is a robust discriminator for DESL, Osm, TFBUT, OPI, OSS, and TMH, but not for ME, MQ, and MGD. Patients with lower tear production levels presented with more severe DED at all three defined cut-off values. Interestingly, the differences in the mean values of DESL were minimal although statistically significant. Thus, the clinical value of different Schirmer levels appears to be limited.
Xie H-T, Sullivan DA, Chen D, Hatton MP, Kam WR, Liu Y. Biomarkers for Progenitor and Differentiated Epithelial Cells in the Human Meibomian Gland. Stem Cells Transl Med 2018;Abstract
The meibomian gland (MG) is a sebaceous gland that secretes through a holocrine process. Because such secretion requires the destruction of MG acinar epithelial cells, they need constant renewal and differentiation. The processes that promote these regenerative events in the human MG are unknown, nor is it known how to distinguish MG progenitor and differentiated cells. We discovered that Lrig1 and DNase2 serve as biomarkers for human MG progenitor and differentiated cells, respectively. Lrig1 is expressed in MG basal epithelial cells in the acinar periphery, a location where progenitor cells originate in sebaceous glands. DNase2 is expressed in the differentiated epithelial cells of the MG central acinus. Furthermore, proliferation stimulates, and differentiation suppresses, Lrig1 expression in human MG epithelial cells. The opposite is true for DNase2 expression. Our biomarker identification may have significant value in clinical efforts to restore MG function and to regenerate MGs after disease-induced dropout. Stem Cells Translational Medicine 2018.
Singh RB, Batta P. Herpes simplex virus keratitis mimicking Acanthamoeba keratitis: a clinicopathological correlation. BMJ Case Rep 2018;2018Abstract
A 36-year-old male, soft contact lens wearer was referred by his primary ophthalmologist for corneal ulcer of the right eye (OD), which was persistent despite topical fluoroquinolone therapy for 1 month. A ring-shaped infiltrate typically seen in Acanthamoeba infection was noted, and topical therapy with chlorhexidine and polyhexamethylene biguanide was initiated. However, the patient's condition deteriorated over the next several weeks; thus, diagnostic and therapeutic penetrating keratoplasty was performed. The postoperative immunohistochemical analysis suggested a diagnosis of herpes simplex virus (HSV) keratitis. The patient ultimately improved after initiation of oral valacyclovir following penetrating keratoplasty. We report a case of a commonly encountered clinical entity, HSV keratitis, with an atypical clinical presentation, masquerading as Acanthamoeba keratitis.
Momtazi L, Dartt DA, Nilsen O, Eidet JR. Molecular layer deposition builds biocompatible substrates for epithelial cells. J Biomed Mater Res A 2018;Abstract
The demand for novel biocompatible materials as surface coating in the field of regenerative medicine is high. We explored molecular layer deposition (MLD) technique for building surface coatings and introduced a new group of substrates consisting of amino acids, or nucleobases, and the biocompatible metal titanium. The substrates were built from titanium tetraisopropoxide (TTIP) with l-lysine, glycine, l-aspartic acid, l-arginine, thymine, uracil, and adenine. Substrates based on zirconium chloride and terephthalic acid were also included. Titanium oxide (TiO ) substrates made by atomic layer deposition and uncoated cover slips served as controls. Rat conjunctival epithelial goblet cells were grown in RPMI 1640 and RT-PCR, immunofluorescence, cell attachment, proliferation, and viability were analyzed. Cells cultured on MLD and uncoated substrates were proliferating (positive for Ki67). Cell attachment after 3 h of culture on MLD substrates was similar to uncoated coverslips (p > 0.05). Compared to uncoated coverslips, cell proliferation assayed with alamarBlue® after 4 days was significantly higher on all MLD substrates (p < 0.05), whereas terephthalic acid-containing MLD substrates reduced proliferation (p < 0.01). Viability assessed by LIVE/DEAD® was high (>85%) for all substrates after 5 days. The novel MLD technique is promising for building biocompatible substrates that direct epithelial cell growth. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2018.
Shao C, Chen Y, Nakao T, Amouzegar A, Yin J, Tahvildari M, Lužnik Z, Chauhan SK, Dana R. Local Delivery of Regulatory T Cells Promotes Corneal Allograft Survival. Transplantation 2018;Abstract
BACKGROUND: Regulatory T cell (Treg)-based immunotherapies have been studied as potential cell-based modalities for promoting transplant survival. However, the efficacy of local delivery of Tregs in corneal transplantation has not been fully elucidated. Herein, we investigated the kinetics of migration of subconjunctivally injected Tregs and their role in promoting corneal allograft survival. METHODS: GFPCD4CD25Foxp3 Tregs were isolated from draining lymph nodes (DLNs) of GFP transgenic mice and were subconjunctivally injected to corneal allograft recipients. Next, Tregs, conventional T cells (Tconv) or a combination of both was locally injected to graft recipients, and graft survival was determined by evaluating opacity scores for 10 weeks. Transplanted mice without treatment served as controls. The frequencies of MHC-IICD11b antigen presenting cells (APCs), IFNγCD4 Th1 cells, and CD45 cells in the DLNs and cornea were evaluated at week 2 posttransplantation using flow cytometry. Expression of IFNγ, IL-10 and TGF-β in the grafts were assessed using RT-PCR and ELISA. RESULTS: GFP Tregs were detected in the ipsilateral cornea and DLNs of recipients 6 hours after injection. Subconjunctival injection of Tregs significantly decreased the frequencies of mature APCs in the graft and DLNs, suppressed Th1 frequencies in DLNs, and inhibited CD45 cell infiltration to the graft. Finally, locally delivered Tregs significantly reduced the expression of IFN-γ, enhanced the levels of IL-10 and TGF-β in the graft, and promoted long-term allograft survival. CONCLUSIONS: Our study elucidates the kinetics of migration of locally delivered Tregs and shows their role in suppressing host immune response against the allograft.
Seyed-Razavi Y, Lopez MJ, Mantopoulos D, Zheng L, Massberg S, Sendra VG, Harris DL, Hamrah P. Kinetics of corneal leukocytes by intravital multiphoton microscopy. FASEB J 2018;:fj201800684RR.Abstract
Corneal immune privilege is integral in maintaining the clear avascular window to the foreign world. The presence of distinct populations of corneal leukocytes (CLs) in the normal cornea has been firmly established. However, their precise function and kinetics remain, as of yet, unclear. Through intravital multiphoton microscopy (IV-MPM), allowing the means to accumulate critical spatial and temporal cellular information, we provide details for long-term investigation of CL morphology and kinetics under steady state and following inflammation. Significant alterations in size and morphology of corneal CD11c dendritic cells (DCs) were noted following acute sterile inflammation, including cell volume (4364.4 ± 489.6 vs. 1787.6 ± 111.0 μm, P < 0.001) and sphericity (0.82 ± 0.01 vs. 0.42 ± 0.02, P < 0.001) compared with steady state. Furthermore, IV-MPM analyses revealed alterations in both the CD11c DC and major histocompatibility complex class II (MHC)-II mature antigen-presenting cell population kinetics during inflammation, including track displacement length (CD11c: 16.57 ± 1.41 vs. 4.64 ± 0.56 μm, P < 0.001; MHC-II: 9.03 ± 0.37 vs. 4.09 ± 0.39, P < 0.001) and velocity (CD11c: 1.91 ± 0.07 μm/min vs. 1.73 ± 0.1302 μm/min; MHC-II: 2.97 ± 0.07 vs. 1.62 ± 0.08, P < 0.001) compared with steady state. Our results reveal in vivo evidence of sessile CL populations exhibiting dendritic morphology under steady state and increased velocity of spherical leukocytes following inflammation. IV-MPM represents a powerful tool to study leukocytes in corneal diseases in context.-Seyed-Razavi, Y., Lopez, M. J., Mantopoulos, D., Zheng, L., Massberg, S., Sendra, V. G., Harris, D. L., Hamrah, P. Kinetics of corneal leukocytes by intravital multiphoton microscopy.
Kobashi H, Ciolino JB. Innovative Development of Contact Lenses. Cornea 2018;Abstract
Contact lenses have been a common means of vision correction for more than half a century. Recent developments have raised the possibility that the next few decades will see a considerable broadening of the range of applications for contact lenses, with associated expansions in the number and type of individuals who consider them a valuable option. The novel applications of contact lenses include treatment platforms for myopic progression, biosensors, and ocular drug delivery. Orthokeratology has shown the most consistent treatment for myopia control with the least side effects. Recent work has resulted in commercialization of a device to monitor intraocular pressure for up to 24 hours, and extensive efforts are underway to develop a contact lens sensor capable of continuous glucose tear film monitoring for the management of diabetes. Other studies on drug-eluting contact lenses have focused on increasing the release duration through molecular imprinting, use of vitamin E, and increased drug binding to polymers by sandwiching a poly (lactic-co-glycolic acid) layer in the lens. This review demonstrates the potential for contact lenses to provide novel opportunities for refractive management, diagnosis, and management of diseases.
Aggarwal S, Cavalcanti BM, Regali L, Cruzat A, Trinidad M, Williams C, Jurkunas UV, Hamrah P. In Vivo Confocal Microscopy Shows Alterations in Nerve Density and Dendritiform Cell Density in Fuchs' Endothelial Corneal Dystrophy. Am J Ophthalmol 2018;Abstract
PURPOSE: To evaluate corneal nerve and immune cell alterations in Fuchs' endothelial corneal dystrophy (FECD) and pseudophakic bullous keratopathy (PBK) by laser in vivo confocal microscopy (IVCM) as correlated to sensation and endothelial cell loss. DESIGN: Prospective, cross-sectional, controlled study. METHODS: 33 eyes with FECD were compared to 13 eyes with PBK and 17 normal age-matched control eyes at a tertiary referral center. FECD was classified into early (without edema) and late stage (with edema). Corneal IVCM (HRT3/RCM) and esthesiometry (Cochet-Bonnet) were performed. Corneal nerve and immune dendritic cell (DC) alterations were evaluated and correlated to clinical parameters. RESULTS: FECD and PBK eyes showed significantly (p=0.001) diminished total nerve length (11.5±1.3 and 2.9±0.7mm/mm) and number (8.8±1.1 and 2.2±0.4 n/frame), compared to controls (23.3±8.1 and 25.9±1.3). Decreased nerves corresponded to diminished sensation in FECD (4.9±0.2cm; R=0.32; p=0.045), compared to controls (5.9±0.04). Early and late stage FECD showed significantly reduced total nerve length (13.1±1.4 and 9.9±1.2 mm/mm, respectively) and number (8.2±2.5 and 6.5±2.1 n/frame), compared to controls (p<0.001). DC density was significantly increased in FECD (57.8±10.4 cells/mmp=0.01), but not in PBK (47.7±11.6; p=0.60) compared to controls (22.5±4.5). A subset of early FECD patients (7/22) demonstrated very high DC density (>100/mm). CONCLUSION: IVCM demonstrates profound diminishment of subbasal corneal nerves in early, late stage FECD, and PBK, correlating to decreased sensation. Increased DC density in early FECD demonstrates potential subclinical inflammation. The data suggest that reduction in subbasal nerves and increased immune activation may play a role in pathophysiology of FECD.
Harris DL, Yamaguchi T, Hamrah P. A Novel Murine Model of Radiation Keratopathy. Invest Ophthalmol Vis Sci 2018;59(10):3889-3896.Abstract
Purpose: Radiation therapy results in severe chronic keratopathy and dry eye disease. We developed a novel mouse model for radiation keratopathy to allow future mechanistic studies. Methods: Six to 8-week-old BALB/c mice underwent sublethal irradiation to the head only from a Cesium-137 irradiator, 2 × 550 rad, 3-hours apart. Irradiated mice were clinically evaluated by corneal fluorescein staining (CFS) at 1, 2, and 3 months, after which corneas were excised and immunofluorescence histochemistry performed with anti-CD45, anti-MHC class II, and anti-β-tubulin antibodies. Results: The survival rate after irradiation was 100%. Mice demonstrated significant CFS and hair loss around the eyes. Corneal nerve density decreased in the central and peripheral corneas (P < 0.01) at 2 and 3 months, respectively. CD45+ immune cell densities increased in the central and peripheral corneas (P < 0.005, P < 0.001) at 2 and 3 months, respectively. MHC class II, a sign of antigen presenting cell activation, significantly increased after irradiation in the central and peripheral corneas at 2 and 3 months (P = 0.02). A strong inverse correlation was noted between decreased corneal nerves and increase in CD45+ cells in the central cornea at 2 (P = 0.04, r = -0.89) and 3 months (P = 0.03, r = -0.91) after irradiation. Conclusions: We present a model of radiation keratopathy and demonstrate significant nerve loss and increase in immune cell influx and activation within months. This model will enable future investigations to understand the effects of radiation therapy on the eye, and to study mechanisms of neuro-immune crosstalk in the cornea.
Satitpitakul V, Sun Z, Suri K, Amouzegar A, Katikireddy KR, Jurkunas UV, Kheirkhah A, Dana R. Vasoactive Intestinal Peptide Promotes Corneal Allograft Survival. Am J Pathol 2018;188(9):2016-2024.Abstract
Corneal transplantation is the most prevalent form of tissue transplantation. The success of corneal transplantation mainly relies on the integrity of corneal endothelial cells (CEnCs), which maintain graft transparency. CEnC density decreases significantly after corneal transplantation even in the absence of graft rejection. To date, different strategies have been used to enhance CEnC survival. The neuropeptide vasoactive intestinal peptide (VIP) improves CEnC integrity during donor cornea tissue storage and protects CEnCs against oxidative stress-induced apoptosis. However, little is known about the effect of exogenous administration of VIP on corneal transplant outcomes. We found that VIP significantly accelerates endothelial wound closure and suppresses interferon-γ- and tumor necrosis factor-α-induced CEnC apoptosis in vitro in a dose-dependent manner. In addition, we found that intracameral administration of VIP to mice undergoing syngeneic corneal transplantation with endothelial injury increases CEnC density and decreases graft opacity scores. Finally, using a mouse model of allogeneic corneal transplantation, we found for the first time that treatment with VIP significantly suppresses posttransplantation CEnC loss and improves corneal allograft survival.
García-Posadas L, Hodges RR, Diebold Y, Dartt DA. Context-Dependent Regulation of Conjunctival Goblet Cell Function by Allergic Mediators. Sci Rep 2018;8(1):12162.Abstract
In the eye, goblet cells responsible for secreting mucins are found in the conjunctiva. When mucin production is not tightly regulated several ocular surface disorders may occur. In this study, the effect of the T helper (Th) 2-type cytokines IL4, IL5, and IL13 on conjunctival goblet cell function was explored. Goblet cells from rat conjunctiva were cultured and characterized. The presence of cytokine receptors was confirmed by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Changes in intracellular [Ca], high molecular weight glycoconjugate secretion, and proliferation were measured after stimulation with Th2 cytokines with or without the allergic mediator histamine. We found that IL4 and IL13 enhance cell proliferation and, along with histamine, stimulate goblet cell secretion. We conclude that the high levels of IL4, IL5, and IL13 that characterize allergic conjunctivitis could be the reason for higher numbers of goblet cells and mucin overproduction found in this condition.
Li M, Mittal SK, Foulsham W, Amouzegar A, Sahu SK, Chauhan SK. Mast cells contribute to the induction of ocular mucosal alloimmunity. Am J Transplant 2018;Abstract
Beyond their historical role as the effector cells in allergic disorders, mast cells have been implicated in regulating both innate and adaptive immune responses. Possessing considerable functional plasticity, mast cells are abundant at mucosal surfaces, where the host and external environments interface. The purpose of this study was to evaluate the contribution of mast cells to allograft rejection at the ocular surface. Using a well-characterized murine model of corneal transplantation, we report that mast cells promote allosensitization. Our data show mast cell frequencies and activation are increased following transplantation. We demonstrate that mast cell inhibition (1) limits the infiltration of inflammatory cells and APC maturation at the graft site, (2) reduces allosensitization and the generation of Th1 cells in draining lymphoid tissues, (3) decreases graft infiltration of alloimmune-inflammatory cells and (4) prolongs allograft survival. Our data demonstrate a novel function of mast cells in promoting allosensitization at the ocular surface. This article is protected by copyright. All rights reserved.
He M, Lippestad M, Li D, Hodges RR, Utheim TP, Dartt DA. Activation of the EGF Receptor by Histamine Receptor Subtypes Stimulates Mucin Secretion in Conjunctival Goblet Cells. Invest Ophthalmol Vis Sci 2018;59(8):3543-3553.Abstract
Purpose: The purpose of this study was to determine if histamine receptors interact with the epidermal growth factor receptor (EGFR) in cultured rat conjunctival goblet cells. Methods: Goblet cells from rat conjunctiva were grown in organ culture. First-passage goblet cells were used in all experiments. Phosphorylated (active) and total EGFR, AKT, and extracellular signal-regulated kinase (ERK)1/2 were measured by Western blot analysis. Cells were preincubated with the EGFR antagonist AG1478 for 30 minutes or small interfering RNA specific to the EGFR for 3 days prior to stimulation with histamine or agonists specific for histamine receptor subtypes for 2 hours. Goblet cell secretion was measured using an enzyme-linked lectin assay. Goblet cells were incubated for 1 hour with the calcium indicator molecule fura-2/AM, and intracellular [Ca2+] ([Ca2+]i) was determined. Data were collected in real time and presented as the actual [Ca2+]i with time and as the change in peak [Ca2+]i. Results: Histamine increased the phosphorylation of the EGFR. Mucin secretion and increase in [Ca2+]i stimulated by histamine, and agonists specific for each histamine receptor subtype were blocked by inhibition of the EGFR. Increase in [Ca2+]i stimulated by histamine and specific agonists for each histamine receptor was also inhibited by TAPI-1, a matrix metalloproteinase (MMP) inhibitor. The histamine-stimulated increase in activation of AKT, but not ERK1/2, was blocked by AG1478. Conclusions: In conjunctival goblet cells, histamine, using all four receptor subtypes, transactivates the EGFR via an MMP. This in turn phosphorylates AKT to increase [Ca2+]i and stimulate mucin secretion.
Tan X, Chen Y, Foulsham W, Amouzegar A, Inomata T, Liu Y, Chauhan SK, Dana R. The immunoregulatory role of corneal epithelium-derived thrombospondin-1 in dry eye disease. Ocul Surf 2018;Abstract
PURPOSE: In this study, we examine the expression of corneal epithelium-derived thrombospondin-1 (TSP-1) and its immunomodulatory functions in a validated murine model of dry eye disease (DED). METHODS: DED was induced in female C57BL/6 using a controlled environment chamber (CEC) for 14 days. mRNA and protein expression of TSP-1 by corneal epithelial cells was quantified using real-time PCR and flow cytometry. Corneal epithelial cells from either naïve or DED mice were cultured with bone marrow derived dendritic cells (BMDCs) in the presence of IFNγ for 48 h, and BMDC expression of MHC-II and CD86 was determined using flow cytometry. Next, either recombinant TSP-1 or anti-TSP-1 antibody was added to the co-culture, and BMDC expression of above activation markers was evaluated. Finally, either DED mice were topically treated with either recombinant TSP-1 or human serum albumin (HSA), and maturation of corneal DCs, expression of inflammatory cytokines, and DED severity were investigated. RESULTS: mRNA expression of TSP-1 by the corneal epithelium was upregulated in DED. Corneal epithelial cells derived from mice with DED demonstrated an enhanced capacity in suppressing BMDC expression of MHC-II and CD86 relative to wild type mice, and this effect was abrogated by TSP-1 blockade and potentiated by recombinant TSP-1. Finally, topical application of recombinant TSP-1 significantly suppressed corneal DC maturation and mRNA expression of pro-inflammatory cytokines, and ameliorated disease severity in mice with DED. CONCLUSIONS: Our study elucidates the function of epithelium-derived TSP-1 in inhibiting DC maturation and shows its translational potential to limit corneal epitheliopathy in DED.

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