Corneal Epithelium Research Articles

Real-ambient PM2.5 induced corneal epithelial barrier disruption through Wnt/β-catenin signaling

Continued daily exposure to fine particulate matter (PM2.5) is linked to increasing risks of ocular surface diseases. However, further study is needed to understand how real-ambient PM2.5 disrupts the barrier function of the corneal epithelial layers and its underlying mechanism. In our study, we utilized a real-ambient PM2.5 exposure system to investigate its effects on the corneal epithelial barrier in C57BL/6Jmice over 4 and 8 weeks. The mean concentration of PM2.5 in the exposure chambers over 8 weeks was 140.18 μg/m3. Following 4 and 8 weeks of continuous PM2.5 exposure, we observed disorganized cellular arrangements in the corneal epithelium of mice. Moreover, PM2.5 exposure led to a significant loss of microvilli on the surface of corneal epithelial cells and noticeable disconnections among epithelial cell layers. Subsequent in vitro analysis revealed that 100 μg/mL PM2.5 activated the Wnt/β-catenin signaling pathway in corneal epithelium, resulting in decreased expression 1.81 fold and 2.25 fold of E-cadherin and ZO-1, respectively, ultimately impairing the corneal epithelial barrier function. Our findings provide the knowledge base for promoting eye health in the context of atmospheric pollution.

Chemotherapy Induced Corneal Changes Assessed by Corneal Confocal Microscopy: A Review

The eye, and the cornea in particular, is a common site of chemotherapy induced toxicity, and ocular side effects of both traditional and novel agents have been reported. Corneal confocal microscopy (CCM) is an in vivo technique that allows for the study of all the corneal layers in an easy, non-invasive and reproducible way via the direct visualization of corneal cell morphologies as well as of sub-basal nerve plexus. Thus, it represents a useful way to identify and monitor chemotherapy induced corneal alterations. This work aims to review the use of CCM in identifying corneal toxicity secondary to chemotherapy treatment, as regards both corneal nerves alterations in the setting of chemotherapy induced peripheral neuropathy (CIPN) and other corneal structure changes, particularly involving the corneal epithelium.

OSSN in South India: Clinical presentation, treatment outcomes, and histopathologic correlations.

This study aimed to analyze the clinical presentation, treatment outcomes, and histopathology features of ocular surface squamous neoplasia (OSSN) in a South Indian population and correlate the area of lesions to the histopathological grade/severity of carcinoma in situ (CIN) and squamous cell carcinoma (SqCC) invasive and noninvasive tumors. The study was a retrospective cross-sectional study. The study reviewed electronic medical records (EMRs) of 99 eyes of 99 South Indian patients who underwent en bloc excision and biopsy for tumors in the corneal and conjunctival epithelium with suspicion of OSSN over 1 year from January 2019 to December 2019. Postoperatively, patients were treated with three cycles of topical 0.04% mitomycin C eye drops. Sixty-three had requisite EMR data with a follow-up period of 1 year. Patients had equal gender distribution with an age range of 28-83 years. The most common clinical variant was leukoplakic lesion, and the area of the lesion was the only predicting factor for SqCC and CIN. Bigger (T2) lesions should be strongly suspected for OSSN and promptly excised. Histopathologic analysis should be performed, and post-op topical mitomycin C or interferon alpha 2b is administered to avoid recurrence. In this study, by correlating the area of the lesion, we introduce a new variable that may aid in clinical prognostication alongside the AJCC classification.

Visual and ocular surface benefits of mini-scleral contact lenses in patients with chronic ocular graft-versus-host disease (GvHD)

Graft-versus-Host disease is a major complication of allogeneic stem cell transplantation. The eyes are a frequently affected organ with a severe dry eye disease being the hallmark manifestation. This retrospective study evaluates the effect of mini-scleral contact lenses on visual acuity, eye-related quality of life and the ocular surface. 62 eyes of 31 patients were included and visual acuity, ocular surface disease index (OSDI) questionnaire results and Oxford grades before and after mini-scleral lens fitting were compared. Median Snellen fraction with mini-scleral lenses was 20/25 (1st 20/30/3rd 20/20) compared to 20/40 median Snellen fraction with spectacles (1st 20/60/3rd 20/25). Median OSDI scores improved from 73 (1st 41.6/3rd 89) before fitting to 27 (1st 14.5/3rd 56) with mini-scleral lenses. Median Oxford grade decreased from 3 before mini-scleral lens fitting (1st 1/3rd 4.75) to 1 after mini-scleral lens fitting (1st 0/3rd 4). Median time of follow up was 717.5 days. Seven patients (22.6%) discontinued therapy with mini-scleral lenses. Mini-scleral lenses are beneficial for most patients with ocular GvHD as they improve visual acuity, eye-related quality of life and the integrity of the corneal epithelium.

A unique and biocompatible corneal collagen crosslinking in vivo

Corneal crosslinking (CXL) is a widely applied technique to halt the progression of ectatic diseases through increasing the thickness and mechanical stiffness of the cornea. This study investigated the biocompatibility and efficiency of a novel CXL procedure using ruthenium and blue light in rat corneas and evaluated parameters important for clinical application. To perform the CXL procedure, the corneal epithelium of rats was removed under anaesthesia, followed by the application of a solution containing ruthenium and sodium persulfate (SPS). The corneas were then exposed to blue light at 430 nm at 3 mW/cm2 for 5 min. Rat corneas were examined and evaluated for corneal opacity, corneal and limbal neovascularization, and corneal epithelial regeneration on days 0, 1, 3, 6, 8, and 14. On day 28, the corneas were isolated for subsequent tissue follow-up and analysis. CXL with ruthenium and blue light showed rapid epithelial healing, with 100% regeneration of the corneal epithelium and no corneal opacity on day 6. The ruthenium group also exhibited significantly reduced corneal (p < 0.01) and limbal neovascularization (p < 0.001). Histological analysis revealed no signs of cellular damage or apoptosis, which further confirms the biocompatibility and nontoxicity of our method. Confocal and scanning electron microscopy (SEM) images confirmed high density of collagen fibrils, indicating efficient crosslinking and enhanced structural integrity. This study is unique that demonstrates in vivo safety, biocompatibility, and functionality of ruthenium and blue light CXL. This approach can prevent toxicity caused by UV-A light and can be an immediate alternative compared to the existing crosslinking procedures that have side effects and clinical risks for the patients.

Development of FK506-loaded maleimide-functionalized cationic niosomes for prolonged retention and therapeutic efficacy in dry eye disease.

Tacrolimus (FK506) is widely used in ocular diseases such as corneal transplantation-host disease, uveitis, conjunctivitis, and dry eye disease (DED). However, its low aqueous solubility and poor ocular retention pose challenges for its application in the eye diseases. This study developed a novel FK506-loaded maleimide-functionalized cationic niosomes (FK506 M-CNS), aiming to prolong the retention time of FK506 in the eye and enhance its therapeutic efficacy. FK506 M-CNS had a particle size of 87.69 ± 1.05nm and zeta potential of 22.06 ± 1.01 mV. Results of histological evaluation through H&E staining and in vitro cytotoxicity of human corneal epithelial cells consistently revealed the excellent biocompatibility of FK506 M-CNS. FK506 M-CNS exhibited superior ocular retention compared to the market product Talymus®. FK506 M-CNS significantly alleviated the symptoms of DED and promoted the recovery of corneal epithelia. FK506 M-CNS group had the lowest expression levels of inflammatory factors associated with DED. These superiorities might be due to the electrostatic interaction between cationic niosomes and negatively charged mucin in the eye, and the covalent binding of maleimide with the thiol group in the mucin. The maleimide group improved the ocular retention and efficacy of FK506, but did not increase the toxicity. Results indicated that FK506 M-CNS had great potential as a nanopharmaceutical in the treatment of ocular diseases, and M-CNS could be a promising drug carrier for ophthalmic drug delivery systems.

Trans-PRK for recurrent epithelial corneal erosion induced by cooking oil accidentally after EVO ICL.

Trans-PRK for recurrent epithelial corneal erosion induced by cooking oil accidentally after EVO ICL.

The Efficacy of Topical Cefiderocol Treatment of Experimental Extensively Drug-Resistant Pseudomonas aeruginosa Keratitis Is Dependent upon the State of the Corneal Epithelium.

Background: An overlooked factor in the efficacy of topical antibiotics to treat bacterial keratitis is the state of the corneal epithelium. Recently, we evaluated topical cefiderocol for the treatment of extensively drug-resistant (XDR) Pseudomonas aeruginosa (PA) keratitis in eyes with the corneal epithelium abraded. The goal of this study was to use the same model with the corneal epithelium left intact to evaluate the efficacy of cefiderocol and other antibiotics and compare the results to those of the previous study. Methods: NZW rabbit corneas with intact epithelium were inoculated with XDRPA. After 16 h, the rabbits were topically treated with cefiderocol 50 mg/mL, ciprofloxacin 0.3%, tobramycin 14 mg/mL, or saline. Following 8 h of treatment, the corneas were harvested for CFU determinations and cefiderocol concentrations. Results: Only cefiderocol significantly decreased CFU of the XDRPA strain compared with saline. The CFU in the cefiderocol and tobramycin-treated corneas for the XDRPA strain with initially intact epithelium were 1.83-1.4 Log10 greater than those produced in corneas with the abraded epithelium (p < 0.05). Cefiderocol concentrations were 5.02× less in corneas with initially intact epithelium. Conclusions: The efficacy of cefiderocol and tobramycin to treat experimental XDRPA keratitis is dependent on the state of the corneal epithelium.

Computational approaches for identifications of altered ion channels in keratoconus.

Keratoconus is an etiologically complex, degenerative corneal disease that eventually leads to loss of corneal integrity. Cells in corneal epithelium and endothelium express various types of ion channels that play important roles in ocular pathology. This emphasizes the need of understanding alterations of ion channels in keratoconus. Differential gene expression analysis was performed to identify deregulated ion channels in keratoconus patients using transcriptomic data. Thereafter correlation analysis of ion channel expression was performed to obtain the changed correlation between ion channels' expression in keratoconus patients versus control samples. Moreover, Protein-protein interaction networks and a pathway map was constructed to identify cellular processes altered due to the deregulation of ion channels. Furthermore, drugs interacting with deregulated ion channels were identified. Total 75 ion channels were found to be deregulated in keratoconus, of which 12 were upregulated and 63 were downregulated. Correlations between ion channel expressions found to be different in control and keratoconus samples. Thereafter, protein-protein interactions network was generated to identify hub ion channels in network. Furthermore, the pathway map was constructed to depict calcium signalling, MAPK signalling, synthesis and secretion of cortisol, and cAMP signalling. The 19 FDA- approved drugs that interact with the 6 deregulated ion channels were identified. Down-regulation of voltage-gated calcium channels can be attributed to reduced cell proliferation and differentiation. Additionally, deregulated ion channels in 3',5'- cyclic adenosine monophosphate signalling may be responsible for elevated cortisol level in progressive keratoconus patients.

A limbal stem cell deficiency murine model with residual limbal stem cells.

Bilateral limbal stem cell deficiency (LSCD) is a significant cause of corneal blindness and is more difficult to treat, as compared with unilateral LSCD because no source of autologous limbal stem cells (LSCs) remains in these patients. Thus, bilateral patients could be candidates for treatment with allogeneic LSC transplants that require long-term systemic immunosuppression therapy. Thus, if possible, for the correct candidates, using autologous LSCs could be a preferred treatment. Recent in vivo laser confocal microscopic examination of the ocular surface in situ , combined with impression cytology, has indicated that some patients diagnosed with a complete bilateral LSCD possess residual LSCs. However, it remains unknown whether these residual LSCs still have stem cell potential due to the lack of animal models that mimic this pathology. The goal of the current study is to make a complete LSCD model that possesses evidence of residual LSCs. We induced complete LSCD in mice using two methods: (1) removed the corneal epithelium and the epithelial basement membrane using a rotating burr, and (2) removed the corneal epithelium using 20% ethanol but retained an intact epithelial basement membrane. A complete LSCD was defined by a lack of CK12-positive corneal epithelial cells and the presence of infiltrating CK19-positive conjunctival epithelial cells. Corneas were examined for wound closure, corneal opacity, LSC exhaustion, and inflammation. We observed that complete LSCD mice without an intact epithelial basement membrane resulted in few residual LSCs. By contrast, complete LSCD mice that retained the epithelial basement membrane were accompanied by a reduced inflammatory response plus a significant number of residual LSCs. This model will allow future studies to determine the function of residual LSCs in complete LSCD.

Impact of Neurostimulation, Immunomodulation, Topical Medication Application, and Surgical Reconstruction on Corneal Nerve Function and Regeneration.

The corneal epithelium, supplied by thousands of nerve endings, plays a substantial role in absorbing and distributing nutrients along the ocular surface. Many studies have explored the influence of various modalities in regulating tear production to manage corneal disorders and dry eye disease. These findings have highlighted the advantages of enhancing corneal nerve function and regeneration through neurostimulation, neural signaling, immunomodulation, topical medication application, and surgical reconstruction. The purpose of this narrative review article was to provide an overview of the current state of knowledge on this topic based on a PubMed database literature search for relevant animal and human studies investigating the modification of the trigeminal pathway to restore corneal nerve function and improve overall ocular health. Further investigation into this area of research is important to help guide new therapeutic targets for the prevention and development of treatments of corneal degeneration.

Importance of different topographic, biometric, and retinal parameters for calculating IOL power

The objective is to evaluate the parameters significantly related to calculating the power of the implanted lens and to determine the importance of different biometric, retina, and corneal aberrations variables. A retrospective cross-sectional observational study used a database of 422 patients who underwent cataract surgery at the Oftalvist Center in Almeria between January 2021 and December 2022. A random forest based on machine learning techniques was proposed to classify the importance of preoperative variables for calculating IOL power. Correlations were explored between implanted IOL power and the most important variables in random forests. The importance of each variable was analyzed using the random forest technique, which established a ranking of feature selections based on different criteria. A positive correlation was found with the random forest variables. Selection: axial length (AL), keratometry preoperative, anterior chamber depth (ACD), measured from corneal epithelium to lens, corneal diameter, lens constant, and astigmatism aberration. The variables coma aberration (p-value = 0,12) and macular thickness (p-value = 0,10) were almost slightly significant. In cataract surgery, the implanted IOL power is mainly correlated with axial length, anterior chamber depth, corneal diameter, lens constant, and preoperative keratometry. New variables such as astigmatism and anterior coma aberration and retina variables such as the preoperative central macular thickness could be included in the new generation of biometric formulas based on artificial intelligence techniques.

Replication kinetics and cytopathic effect of feline calicivirus in feline corneal epithelial cells.

To determine the replication kinetics and cytopathic effect (CPE) of feline calicivirus (FCV) in feline corneal epithelial cells (FCEC). Seven archived FCV isolates and one archived feline herpesvirus type 1 (FHV-1) isolate, previously obtained from eight domestic short hair cats. FCV RNA was extracted for sequencing using Illumina MiSeq, to identify three genomically diverse isolates for further testing. Following reference-based assembly, viral genomes were annotated and assessed. Superficial keratectomies were performed to isolate the corneal epithelium of cats and the cells were cultured invitro. FCEC were infected with the three chosen FCV isolates and one FHV-1 isolate at two different multiplicity of infection ratios (MOIs, 0.1 and 0.01 PFU/cell) and virus titration was assessed at 0, 2, 6, 12, 24, and 48 h post-infection (hpi). Viral identity was confirmed by RT-qPCR. Three genomically diverse FCV isolates were chosen for further assessment in the FCEC model. All infections of FCEC with FCV led to visible CPE, characterized by epithelial cell rounding and detachment from the plate by 24 hpi, while FHV-1 led to visible CPE within 48 hpi. All three of the FCV isolates replicated effectively in FCEC at both 0.1 and 0.01 MOI, with a peak increase in titer approximately 12-24 hpi. The results support the possible role of FCV as a primary pathogen of the feline ocular surface. FCV replicates in FCEC invitro, leading to profound CPE.

Corneal Epithelial Remodeling Following Cylinder Correction With SMILE or FS-LASIK: A Contralateral Comparative Study.

To compare the corneal epithelial remodeling in eyes with high astigmatism that had small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). Seventy-four patients with myopic astigmatism of greater than -2.00 diopters (D) and little binocular difference in spherical equivalent were included in this contralateral comparative study. All patients received SMILE in one eye and FS-LASIK in the other eye randomly. The corneal epithelial remodeling pattern was mapped using the latest RTVue spectral-domain optical coherence tomographer (Optovue) by region. Satisfactory refractive correction was achieved in all enrolled eyes with either SMILE or FS-LASIK. The corneal epithelium gradually thickened following surgical cylinder correction, distributing mainly along the flat medium. The corneal epithelium proliferation is milder centrally but more pronounced in the mid-peripheral area after SMILE, compared with FS-LASIK. The flat-steep difference in corneal epithelial thickness (CET) is evident in the mid-peripheral and peripheral areas, which is more obvious in SMILE. Residual cylinder was positively correlated with CET in eyes that had FS-LASIK, but not SMILE. More importantly, these epithelial changes were positively correlated with the ablation depth and higher order aberrations following surgical refractive correction. The postoperative CET map varied between SMILE and FS-LASIK. In eyes with high astigmatism, SMILE surgery is followed by milder and more stable corneal epithelial thickening. Moreover, the corneal epithelium is sensitive to stromal ablation and corneal remodeling is crucial to the postoperative visual quality. This study rigorously distinguished the CET difference between SMILE and FS-LASIK in astigmatic eyes and shed light on subsequent research. [J Refract Surg. 2024;40(10);e728-e741.].

Foxp3+ regulatory T cells reside within the corneal epithelium and co-localize with limbal stem cells

In this study we investigated the presence of resident Foxp3+ regulatory T cells (Tregs) within the cornea and assessed the role of resident Tregs in corneal epithelial wound healing. Using a mouse model, we showed that in the steady state Foxp3+Tregs are either in close proximity or co-localize with ABCG2+ limbal stem cells. We also showed that these Tregs reside within the epithelial layer and not the corneal stroma. In addition, using a mouse model of mechanical injury, we demonstrated that depletion of Tregs from the cornea prior to corneal mechanical injury, using subconjunctival injection of anti-CD25, was associated with delayed epithelial healing. These results suggest a role for cornea resident Tregs in corneal epithelial cell function and wound healing and opens doors for further exploration of the role of Tregs in limbal stem cell function and survival.

Glucocorticoid Receptor Signaling Is Critical for Mouse Corneal Development, Inhibition of Inflammatory Response, and Neovascularization of the Cornea

The cornea protects the interior of the eye from external agents such as bacteria, viruses, and debris. Synthetic glucocorticoids are widely prescribed in the treatment of ocular infections and disorders. The actions of glucocorticoids are mediated by the glucocorticoid receptor (GR); however, the molecular and physiological functions of GR signaling in the cornea are poorly understood. This study found that treatment of mice with glucocorticoid eye drops led to a profound regulation of the corneal transcriptome. These glucocorticoid-regulated genes were associated with multiple biological functions, including the immune response. To understand the direct role of GR signaling in the cornea, mice with conditional knockout of GRs in the corneal epithelium were generated. Mice lacking corneal GRs exhibited microphthalmia, loss of pupils, a deformed and opaque lens, and mislocalization of key structural proteins within the corneal epithelial layers. Global transcriptomic approaches revealed that loss of GR signaling in the cornea also resulted in the dysregulation of a large cohort of genes strongly associated with an enhanced inflammatory response. Finally, corneal GR signaling was required for preventing neovascularization of blood and lymphatic vessels and thereby immune cell infiltration of the cornea. These results reveal that corneal GR signaling plays a critical role in ocular development and in maintaining the homeostasis of the eye.

PM10 dysregulates epithelial barrier function in human corneal epithelial cells that is restored by antioxidant SKQ1

Exposure to airborne particulate <10 μm (PM10) adversely affects the ocular surface. This study tested PM10 on epithelial barrier integrity in immortalized human corneal epithelial cells (HCE-2) and mouse cornea, and whether antioxidant SKQ1 is restorative. HCE-2 were exposed to 100 μg/ml PM10 ± SKQ1 for 24 h. An Electric Cell-Substrate Impedance Sensing (ECIS) system monitored the impact of PM10. RT-PCR, western blotting and immunofluorescence measured levels of barrier and associated proteins, stanniocalcin 2 (STC2), and a kit measured total calcium. In vivo, female C57BL/6 mice were exposed to either control air or PM10 (±SKQ1) in a whole-body exposure chamber, and barrier associated proteins tested. Tight junction and mucins proteins in the cornea were tested. In HCE-2, PM0 vs control significantly reduced mRNA and protein levels of tight junction and adherence proteins, and mucins. ECIS data demonstrated that PM10 vs control cells exhibited a significant decrease in epithelial barrier strength at 4000 Hz indicated by reduced impedance and resistance. PM10 also upregulated STC2 protein and total calcium levels. In vivo, PM10 vs control reduced zonula occludens 1 and mucins. SKQ1 pre-treatment reversed PM10 effects both in vitro and in vivo. In conclusion, PM10 exposure reduced tight junction and mucin proteins, and compromised the seal between cells in the corneal epithelium leading to decreased epithelial barrier strength. This effect was reversed by SKQ1. Since the corneal epithelium forms the first line of defense against air pollutants, including PM10, preserving its integrity using antioxidants such as SKQ1 is crucial in reducing the occurrence of ocular surface disorders.

PAX6-WNK2 Axis Governs Corneal Epithelial Homeostasis.

Limbal stem/progenitor cells (LSCs) continuously proliferate and differentiate to replenish the corneal epithelium and play a vital role in corneal function and normal vision. A previous study revealed that paired box 6 (PAX6) is a master transcription factor involved in determining the fate of corneal epithelial cells (CECs). However, the molecular events downstream of PAX6 remain largely unknown. In this study, we aimed to clarify the regulation network of PAX6 in driving CEC differentiation. An air-liquid culture system was used to differentiate LSCs into mature CECs. Specific targeting PAX6 short-hairpin RNAs were used to knock down PAX6 in LSC. RNA sequencing (RNA-seq) was used to analyze shPAX6-transfected CECs and CEC differentiation-associated genes to identify the potential downstream targets of PAX6. RNA-seq analysis, quantitative real-time PCR, and immunofluorescence staining were performed to clarify the function of WNK lysine deficient protein kinase 2 (WNK2), a downstream target of PAX6, and its relationship with corneal diseases. WNK2 expression increased during CEC differentiation and decreased upon PAX6 depletion. The distribution of WNK2 was specifically limited to the central corneal epithelium and suprabasal layer of the limbus. Knockdown of WNK2 impaired the expression of CEC-specific markers (KRT12, ALDH3A1, and CLU), disrupted the corneal differentiation process, and activated the terms of keratinization, inflammation, and cell proliferation, consistent with PAX6-depleted CEC and published microbial keratitis. Thus, aberrant expression of WNK2 was linked to corneal ulcers. As a downstream target of PAX6, WNK2 plays an essential role in corneal epithelial cell differentiation and maintenance of corneal homeostasis.

An agonist of the adenosine A2A receptor, CGS21680, promotes corneal epithelial wound healing via the YAP signalling pathway.

The adenosine A2A receptor (A2AR) is involved in various physiological and pathological processes in the eye; however, the role of the A2AR signalling in corneal epithelial wound healing is not known. Here, the expression, therapeutic effects and signalling mechanism of A2AR in corneal epithelial wound healing were investigated using the A2AR agonist CGS21680. A2AR localization and expression during wound healing in the murine cornea were determined by immunofluorescence staining, quantitative reverse transcription polymerase chain reaction (RT-qPCR) and western blotting. The effect of CGS21680 on corneal epithelial wound healing in the lesioned corneal and cultured human corneal epithelial cells (hCECs) by modulating cellular proliferation and migration was critically evaluated. The role of Hippo-YAP signalling in mediating the CGS21680 effect on wound healing by pharmacological inhibition of YAP signalling was explored. A2AR expression was up-regulated after corneal epithelial injury. Topical administration of CGS21680 dose-dependently promoted corneal epithelial wound healing in the injured corneal epithelium by promoting cellular proliferation. Furthermore, CGS21680 accelerated the cellular proliferation and migration of hCECs in vitro. A2AR activation promoted early up-regulation and later down-regulation of YAP signalling molecules, and pharmacological inhibition of YAP signalling reverted CGS21680-mediated wound healing effect in vivo and in vitro. A2AR activation promotes wound healing by enhancing cellular proliferation and migration through the YAP signalling pathway. A2ARs play an important role in the maintenance of corneal epithelium integrity and may represent a novel therapeutic target for facilitating corneal epithelial wound healing.

Mineralocorticoid receptor expression and the effects of the mineralocorticoid receptor antagonist spironolactone in a murine model of graft-versus-host disease

PurposeThe topical administration of spironolactone, a mineralocorticoid receptor antagonist (MRA) improves dry eye symptoms in patients with ocular graft-versus-host disease (GVHD); however, the detailed mechanism remains unclear. This study aimed to investigate the effects of spironolactone eyedrops on the ocular surface using a chronic GVHD (cGVHD) mouse model and to determine the expression of the mineralocorticoid receptor (MR). MethodsA cGVHD mouse model was established by allogeneic bone marrow transplantation (BMT) from B10.D2 mice to BALB/c mice. Subsequently, cGVHD mice were treated with either 0.005 % spironolactone or vehicle eyedrops. The eyelids, cornea and conjunctiva of the recipients were analyzed at 4-week intervals post-BMT in both groups. ResultsSigns of ocular GVHD, such as corneal epithelial damage, depletion of meibomian glands, and inflammatory cell infiltration onto the ocular surface, were significantly decreased in cGVHD mice treated with spironolactone eyedrops. The expression of the MR NR3C2 in the corneal and conjunctival epithelia was significantly increased in cGVHD mice. HSP47+NR3C2+ MR-expressing fibroblasts, CD45+NR3C2+ MR-expressing leukocytes, and CD4+NR3C2+ MR-expressing T cells infiltrated the ocular surface tissue of cGVHD mice significantly more than that of syngeneic controls. ConclusionsMR expression is increased in epithelial cells, fibroblasts, and T cells in a murine cGVHD model, whereas MRA and spironolactone eyedrops could attenuate the severity of ocular GVHD. These findings suggest that MR signaling partially contributes to the development of ocular GVHD in this mouse model.