RARE DISEASE
Limbal stem cell deficiency
Limbal stem cell deficiency
Limbal stem cell deficiency
Drug discovery
9
drugs
With orphan designations
Overview
Limbal stem cell deficiency (LSCD) is a vision-threatening condition caused by dysfunction or loss of limbal stem cells, impairing corneal epithelial regeneration. This leads to conjunctivalization, neovascularization, and opacity, with symptoms including chronic pain, photophobia, and irreversible vision loss. Etiologies range from trauma (chemical burns, surgery) to autoimmune disorders (Stevens-Johnson syndrome) and congenital conditions (aniridia). Diagnosis relies on clinical evaluation and staging systems, while treatment combines medical optimization of the ocular surface and surgical stem cell transplantation [1][4][9][12].
Population
Primarily affects young, working-age males (mean age ~35 years), with higher incidence in rural populations and those with limited education [12][16][19].
Unilateral cases (50–60%) are more common than bilateral, often linked to chemical injuries or contact lens misuse; bilateral cases typically stem from autoimmune/inflammatory conditions [2][4][12].
Categories: rare ophthalmic disorders
Research Papers
1,469 drug discovery papers about Limbal stem cell deficiency, with 3 first-in-class and 10 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
1,469 drug discovery papers about Limbal stem cell deficiency, with 3 first-in-class and 10 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
categories:
Small molecules
cell therapies
2026-09-09 | 3D Culture Reverses Limbal Niche Cell Replicative Aging via FOSL1 Upregulation.
Limbal niche cells (LNCs) serve as essential regulators of limbal microenvironmental homeostasis and corneal epithelial wound repair, representing a promising therapeutic resource for limbal stem cell deficiency (LSCD). However, their clinical application is constrained by replicative aging during in vitro expansion. In this study, we investigated whether a three-dimensional (3D) Matrigel-based culture system could modulate replicative aging in LNCs. Compared with conventional two-dimensional (2D) culture, 3D-cultured LNCs restored stemness marker expression and enhanced proliferative capacity. Concurrently, these cells displayed reduced senescence-associated β-galactosidase (SA-β-gal) activity and decreased expression of senescence-associated proteins, including p16, p21, p53, and γ-H2AX. Single-cell RNA sequencing (scRNA-seq) analysis revealed prominent upregulation of FOS-like antigen 1 (FOSL1). FOSL1 is a component of the AP-1 transcription factor family and participates in cell proliferation and stress adaptation. Functional assays using an in vitro replicative aging model showed that FOSL1 knockdown in early-passage (P4) LNCs accelerated senescence, whereas FOSL1 overexpression in late-passage (P11) LNCs attenuated senescence. Mechanistically, FOSL1 knockdown induced mitochondrial dysfunction characterized by elevated levels of mitochondrial superoxide and cellular reactive oxygen species (ROS), as well as a decrease in mitochondrial membrane potential, while FOSL1 overexpression preserved mitochondrial integrity and function. Collectively, our findings demonstrate that 3D culture reverses LNC replicative aging through FOSL1-mediated enhancement of mitochondrial function, providing a microenvironment-based strategy to counteract replicative aging in adult stem cells for corneal regenerative therapy.
2026-08-29 | Safety and tolerability of topical mesenchymal stromal cell secretome in persistent corneal epithelial disease-a phase 1b clinical trial.
To investigate the safety and tolerability of a topical allogeneic bone marrow-derived mesenchymal stromal cell (BM-MSC) secretome in chronic corneal epithelial disease. A prospective single-center, uncontrolled, open-label phase 1b clinical trial was conducted.A dose escalation study design was used. Participants were patients with persistent corneal epithelial disease in the setting of neurotrophic keratitis and/or limbal stem cell deficiency.The first 3 participants were treated with topical BM-MSC secretome in 1 eye twice daily, the next 3 participants received the treatment 4 times a day, and the last 3 received it 6 times a day for 28 days. The primary outcomes were safety and the maximum tolerated dose (MTD) of the topical BM-MSC secretome. Ocular surface toxicity and other ocular or systemic treatment-emergent adverse events were assessed up to 90 days. Demonstration of safety on day 28 was required for each dosing frequency group before escalating to the next higher dose. A total of 9 participants were enrolled. No dose-limiting toxicities (DLTs) were observed in the 6 patients who received the BM-MSC secretome 2 or 4 times a day. Two of the 3 participants who were treated 6 times a day developed reversible DLTs, including a new corneal epithelial defect and increased central corneal staining with a consequent transient reduction in best-corrected visual acuity (BCVA). Potential signals of clinical efficacy were observed, particularly in the BCVA and corneal sensation in the majority of participants who completed the treatment. Topical BM-MSC secretome 2 or 4 times a day for 28 days was safe and well tolerated without signs of systemic or ocular toxicity in persistent corneal epithelial disease.
2026-08-24 | Eight-Year Outcomes of Staged Penetrating Keratoplasty After Simple Limbal Epithelial Transplantation in Ocular Surface Burns: A Case Report.
The purpose of this article was to report long-term outcomes of staged simple limbal epithelial transplantation (SLET) followed by penetrating keratoplasty (PKP) in patients with severe ocular surface burns. Two patients with unilateral severe ocular surface burns and limbal stem cell deficiency (LSCD) underwent SLET performed by a single surgeon. After ocular surface stabilization, sequential PKP combined with cataract extraction and posterior chamber intraocular lens implantation was performed. Patients were followed for 8 years. Anatomical success (stable, epithelized surface, and clear graft) and functional outcomes (best-corrected visual acuity) were assessed. Both eyes achieved sustained ocular surface stability before keratoplasty. At 8 years, clear grafts with stable epithelium were maintained in both cases. Final best-corrected visual acuity was 20/20 (with contact lens) and 20/120, respectively. No episodes of graft rejection, persistent epithelial defects, or vision-threatening complications were observed during follow-up. A staged approach with SLET followed by PKP may provide favorable long-term anatomical and visual outcomes in selected patients with severe ocular surface burns and LSCD. Larger studies are needed to validate these findings.
2026-08-09 | State-of-the-art advances in tissue-engineered corneal substitutes: a systematic review (2020-2025).
Corneal blindness remains a major global health burden, limited by donor shortage and graft-related complications. Tissue-engineered corneal substitutes have emerged as a promising alternative, aiming to restore corneal structure and function through bioengineered constructs. To systematically review recent advances (2020-2025) in tissue-engineered corneal substitutes, classifying them according to the corneal layer replaced and evaluating their biological, optical, and functional performance, as well as their translational potential for clinical application. A systematic review. A systematic review was conducted following Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) 2020 guidelines. Searches were performed in PubMed/MEDLINE, Scopus, and Web of Science using predefined keywords related to corneal tissue engineering. Eligible studies included experimental, preclinical, or clinical studies published between January 2020 and June 2025 describing cell-based corneal substitutes. Studies focused on keratoprostheses (KPros), acellular scaffolds, or non-cellular biomaterials were excluded. Fourteen studies met the inclusion criteria: five endothelial, three stromal, one epithelial, and five epithelium-stroma substitutes. Endothelial models demonstrated cell viability, expression of tight junction proteins (ZO-1, Na+/K+-ATPase), and partial restoration of corneal transparency in animal and ex vivo systems. Stromal models incorporated advanced biofabrication techniques such as 3D bioprinting and neuronal co-culture, achieving > 80% optical transmittance and adequate biomechanical properties. The single epithelial model achieved complete re-epithelialization in a rabbit limbal deficiency model. Multilayered epithelium-stroma substitutes, including the NANOULCOR (Tissue Engineering Group, University of Granada, Granada, Spain) construct, exhibited safety and feasibility in preclinical and early clinical studies. Recent progress in corneal tissue engineering has yielded increasingly functional and biocompatible substitutes that replicate native corneal architecture. However, most studies remain limited by small sample sizes, short follow-up, and reliance on animal models. Further standardized clinical trials are required for clinical translation. Not applicable.
2026-08-04 | Refining How We Diagnose and Classify Limbal Stem Cell deficiency.
Refining How We Diagnose and Classify Limbal Stem Cell deficiency CLINICAL RELEVANCE: With the development of multimodal anterior segment imaging modalities and molecular diagnostic tests for the diagnosis and staging of limbal stem cell deficiency (LSCD), and better understanding of LSCD presentation and pathophysiology, a comprehensive step-by-step algorithm is established to more precisely evaluate the ocular surface environment and stage the disease. This is a review of the most relevant publications on the method of diagnosing and staging LSCD. Clinical presentation and pathophysiology of LSCD were reviewed. Factors that impact LSC function and survival were discussed and outlined. The International LSCD Working Group has put forth the first guidelines on the clinical definition, classification, diagnosis, staging, and management of LSCD. Precise diagnosis and staging of LSCD is limited by subjective nature of the fluorescein staining test. As other comorbidities negatively impact the function of both corneal epithelial cells and LSCs, assessment of these comorbidities such as dry eye disease, ocular surface inflammation, corneal innervation, conjunctival health, medication toxicity, and eyelid abnormalities should be included in the initial evaluation of LSC function. Advances in anterior segment imaging, including anterior segment optical coherence tomography and in vivo confocal microscopy allow objective evaluation of epithelial phenotype, cellular morphology, basal cell density, corneal innervation, and inflammatory cell infiltration in both the cornea and limbus. The knowledge of ocular surface microstructure provides important information regarding the corneal and limbal epithelial cell function, remaining LSC reserve, and factors associated with LSCD improvement after all comorbidities are treated. Impression cytology remains a valuable tool for objectively confirming conjunctivalization through assessment of epithelial phenotype. LSCD diagnosis and classification have advanced beyond the simple fluorescein staining test for the detection of abnormal epithelial cells on the corneal surface. A comprehensive assessment of the LSC function and the ocular surface environment by integrating multimodal imaging and molecular testing enables precise staging of LSC function and identification of factors that influence LSCD reversibility. Adoption of a standardized multimodal diagnostic framework will improve diagnostic accuracy, guide the management of the disease, facilitate comparisons across clinical studies, and support the development and evaluation of emerging cell-based and cell-free regenerative therapies for LSCD.
small molecules
2026-09-22 | Effect of Combined Rebamipide and Cyclosporine Therapy in Limbal Stem Cell Deficiency Caused by Long-term Soft Contact Lens Wear
Purpose: To evaluate the clinical outcomes of combined aggressive nonsurgical treatments, including combined rebamipide and cyclosporine therapy, in patients with stage IIb limbal stem cell deficiency (LSCD) induced by long-term silicone hydrogel contact lens wear.Methods: A retrospective case series analysis was conducted on four eyes of three patients with stage IIb LSCD with a history of prolonged contact lens wear, who were refractory to artificial tears and other conventional conservative treatments for at least 1 month. Contact lens use was discontinued in all the patients, and topical rebamipide and cyclosporine were administered in combination. Changes in the best-corrected visual acuity, corneal epithelial stability, degree of corneal conjunctivalization, and superficial corneal neovascularization were evaluated before and after treatment.Results: All patients demonstrated improved corneal epithelial stability after combination therapy. The progression of corneal epithelial opacity and conjunctivalization was suppressed, and a marked improvement in visual acuity was observed in some cases. No significant drug-related adverse events were observed during the treatment period.Conclusions: Aggressive nonsurgical treatment, including combined topical therapy with rebamipide and cyclosporine, topical steroids, and supportive treatment, may be an effective treatment option for patients with stage IIb contact lens–induced LSCD who are unresponsive to artificial tear–based conservative management. This strategy may be considered before surgical intervention in selected patients with stage IIb LSCD in whom the residual limbal function is preserved.
2026-09-16 | Corticosteroid-Sparing Systemic Immunosuppression for Ocular Surface Stem Cell Transplantation.
The goal of our study was to highlight the results of a corticosteroid-sparing immunosuppressive regimen for patients with limbal stem cell deficiency (LSCD) undergoing ocular surface stem cell transplantation (OSST). This retrospective review studied patients with LSCD undergoing OSST from 2014 to 2023, evaluating the evolving corticosteroid-sparing systemic immunosuppression regimen over time. Inclusion criteria encompassed patients aged 18 to 69 with total/near-total LSCD that underwent OSST and were treated postoperatively with oral corticosteroids. Outcomes included ocular surface stability, visual acuity, and rates of rejection/failure. Corticosteroid dosage, taper length, and corticosteroid-related side effects were recorded. There were 166 eyes that met the inclusion criteria. The mean starting dose of prednisone was 34.5 mg (range: 30-60), with a mean taper length of 13.3 weeks (range: 3-59 weeks). There were 66 eyes that underwent a keratolimbal allograft, 96 eyes that underwent a living-related conjunctival limbal allograft, and 28 eyes that underwent a conjunctival limbal autograft. At the last follow-up, 72.3% of eyes had a stable ocular surface and 60.2% had visual improvement of at least 2 lines. Approximately 19.9% of eyes developed rejection and 13.3% developed failure during the follow-up period. A modified corticosteroid-sparing immunosuppression protocol for OSST has shown significant efficacy in restoring the ocular surface of patients with LSCD. A corticosteroid-sparing immunosuppressive regimen mitigates the side effects related to oral corticosteroid usage, without compromising the stability of the stem cell graft.
2026-07-29 | Enhancing the Outgrowth of Oral Mucosal Cell Sheets for Cultivated Rabbit Oral Mucosal Epithelial Transplantation with ROCK Inhibitor.
Cultivated oral mucosal epithelial transplantation (COMET) is an effective way to treat limbal stem cell deficiency (LSCD), but its clinical usage is limited due to prolonged cultivation time and complexity. Rho-associated protein kinase (ROCK) inhibitors have been found to enhance cell proliferation, migration, and cytoskeleton maintenance. We investigated whether ROCK inhibitor (Y-27632) can be used to enhance the growth of oral mucosal epithelial cell sheet while remaining their characteristics, optimizing COMET usage for LSCD treatment. Oral mucosal epithelial cells were harvested from rabbits and cultured using a collagenase-based isolation technique. Cells were seeded in a transwell plate with or without amniotic membrane (AM) and Y-27632. The speed of cell sheet outgrowth and cell density were evaluated. Stem cell marker (p63), cytokeratin (K3, K4 and K13) and junctional protein markers (ZO-1, occludin, connexin 43) were analyzed by immunostaining with confocal microscopy. Y-27632 and AM coating facilitated the outgrowth of cell sheets, resulting in a larger expansion area from day 7 to day 15 (p < 0.05). Y-27632 treatment dose-dependently increased basal cell density (p < 0.05) and inhibited the squamous differentiation of the superficial layer, while maintaining cytokeratin and junctional protein markers expression. Y-27632 increased the p63-positive cells population (p < 0.05), which may play a role in maintaining stem cell properties and inhibiting differentiation. Y-27632, together with AM, provides an efficient and supportive environment for producing oral mucosal epithelial cell sheets for transplantation. They might serve as an adjunctive agent to accelerate oral epithelial cell-based therapy for the treatment of limbal stem cell deficiency.
2026-06-30 | 3% diquafosol sodium combined with 0.1% fluorometholone for postoperative dry eye in pterygium patients with preoperative tear deficiency: a pilot retrospective study
Background To evaluate the clinical efficacy and safety of 3% diquafosol sodium combined with 0.1% fluorometholone for postoperative dry eye in pterygium patients with preoperative tear deficiency. Methods This single-center retrospective study included 82 pterygium patients (82 eyes) with preoperative tear deficiency who underwent pterygium excision combined with limbal stem cell transplantation. Patients were divided into an observation group (diquafosol + fluorometholone, n = 42) and a control group (sodium hyaluronate + fluorometholone, n = 40). Tear break-up time (BUT), corneal fluorescein staining (CFS) score, Ocular Surface Disease Index (OSDI), Schirmer I test (SIt), and intraocular pressure (IOP) were assessed preoperatively and at 2 and 4 weeks postoperatively. Adverse events and complications were recorded. Results Eighty patients completed follow-up (41 in observation group, 39 in control group). At 4 weeks postoperatively, the observation group showed significantly longer BUT, lower CFS and OSDI scores, and higher SIt values compared to the control group (all p < 0.05). No significant intergroup differences in IOP were observed at any time point. Transient ocular stinging occurred in 2 patients (4.88%) in the observation group, with no severe complications in either group. Conclusion In this pilot study, the combination of 3% diquafosol sodium and 0.1% fluorometholone showed preliminary evidence of improving tear film stability, repairing ocular surface damage, and alleviating dry eye symptoms in pterygium patients with preoperative tear deficiency, without significantly affecting IOP. Its efficacy appeared superior to sodium hyaluronate combined with fluorometholone. These findings support further investigation in larger, longer-term randomized controlled trials.
2026-05-29 | Lactate-fueled H3K18 lactylation sustains ΔNp63α-dependent self-renewal in limbal epithelial stem cells.
The interplay between metabolic reprogramming and epigenetic regulation in controlling stem cell fate remains incompletely understood, particularly in limbal epithelial stem cells (LESCs) that are essential for corneal homeostasis. Here, we identify glycolytic lactate as a critical metabolic regulator that sustains LESC self-renewal through an epigenetic mechanism. We established a progenitor-like LESC model via MYC overexpression (oeMYC-LESCs). Using CUT&Tag, RNA-seq, and a mouse corneal epithelial injury model, we found that oeMYC-LESCs exhibit enhanced glycolysis and lactate efflux, which fueled p300/CBP-mediated histone lactylation, especially histone H3 lysine 18 lactylation (H3K18la). Enrichment of H3K18la at the ΔNp63α promoter drives its transcriptional activation, thereby sustaining LESC self-renewal. Inhibition of lactate generation depleted H3K18la, suppressed ΔNp63α, and consequently impaired LESC function; notably, these phenotypes were partially rescued by exogenous lactate supplementation. In vivo experiments confirmed that lactate accelerates corneal re-epithelialization and upregulates ΔNp63α in an H3K18la-dependent manner, whereas pharmacological blockade of lactate production delayed wound healing. Collectively, our study reveals a lactate-H3K18la-ΔNp63α axis as a key metabolic-epigenetic-transcriptional mechanism sustaining LESC self-renewal, suggesting a novel therapeutic target for treating limbal stem cell deficiency.
proteins
2026-05-27 | A Novel Selective Strategy for Bioactive Limbal Stem Cells Primary Culture Using Deep Cryopreservation and IL-1β Precondition.
Limbal stem cell (LSC) transplantation is an important treatment for limbal stem cell deficiency (LSCD), but low efficacy in maintaining LSC stemness during in vitro expansion greatly affects its wider application. The primary contributing factors include a low proportion of stem cells and the lack of a stable, supportive microenvironment over prolonged culture. Rabbit corneal tissues preserved under deep cryogenic conditions for more than six months retain viable limbal stem cells (LSCs), and primary LSCs isolated from these tissues exhibit robust stem cell characteristics. It is noteworthy that the NLRP3/Caspase-1/IL-1β signaling axis was activated in corneal epithelial cells, and outer limbal layers preserved for one or two years. Based on these findings, a combined strategy integrating deep cryopreservation with IL-1β induction was established for the processing of limbal tissues. The combined cryogenic and IL-1β preconditioning yielded primary LSCs with maintained p63+ cell proportions, a reduction in K3+ differentiated cells from approximately 80% to 60%, and a 6.25-fold increase in colony-forming efficiency. In addition, an increased proportion of cells in the G2/M phase and enhanced proliferative capacity were observed. The enriched LSC population also exhibited improved stratified epithelial reconstruction potential. These findings identify an effective strategy for preserving and enriching LSCs from limbal tissue, providing a practical and efficient approach for LSC preparation prior to transplantation. Further in vivo studies will be important to validate the functional performance of these cells in ocular surface reconstruction.
2026-01-31 | Association Between Neurotrophic Keratitis and Limbal Stem Cell Deficiency.
To investigate changes in corneal nerves, immune cells, and limbal epithelial stem cells (LESCs) in neurotrophic keratitis (NK) patients; to analyze correlations between these parameters and clinical manifestations; and to monitor long-term corneal changes in NK patients receiving recombinant human nerve growth factor (rh-NGF). Cross-sectional study with an interventional case series. A total of 54 NK patients (55 eyes) and 57 healthy controls (59 eyes) were enrolled. In vivo confocal microscopy (IVCM) was performed to evaluate subbasal nerve fiber parameters, density of limbal epithelial stem cells (LESCs) in different directions, and dendritic cell (DC) status. Longitudinal changes in these parameters are recorded at baseline, weeks 4 and 8, and the 2-year follow-up in the rh-NGF-treated subgroup (7 eyes of 7 patients). Correlation analyses are conducted among all parameters in the NK group. In patients with neurotrophic keratopathy (NK), corneal nerve fiber density (CNFD) (P < .01), nerve fiber length (CNFL) (P < .01), and nerve branch density (CNBD) (P < .01) were significantly less than in healthy controls. Similarly, central BCD (P < .001) and peripheral LESCs density (P < .001) were markedly lower in NK group. In contrast, DCs density (P < .001) and activation ratio (P < .001) of patients with NK were higher. Correlation analyses revealed that CNFD was positively correlated with LESCs density (ρ = 0.46; P < .001), and negatively correlated with fluorescein staining scores (ρ = -0.46; P < .001) and DC density (ρ = -0.57; P < .001). LESC density was negatively correlated with both fluorescein staining scores (ρ = -0.62; P < .001) and mean DC area (ρ = -0.44; P < .001), whereas fluorescein staining scores were positively correlated with DC density (ρ = 0.44; P < .001). Compared with baseline, improvements in LESC density, DC density, activation, and fluorescein staining scores became observed at 4 weeks of rh-NGF treatment, whereas nerve regeneration became detectable after 8 weeks and showed significant recovery by year 2. This study demonstrates that patients with NK exhibit corneal nerve damage, limbal stem cell deficiency, and immune cell activation, with significant correlations observed among these alterations. Short-term treatment with rh-NGF may initiate corneal recovery by first improving the limbal microenvironment and modulating immune responses, thereby promoting a regenerative feedback loop that supports sustained nerve regeneration and epithelial repair.
2026-01-19 | Corneal macrophages and limbal stem cells: emerging roles in ocular surface regeneration.
Corneal integrity and visual acuity rely on limbal stem cells (LSCs) and immune homeostasis. Macrophages, as critical immune regulators, are increasingly recognized for their roles in stem cell niche maintenance and tissue regeneration. Recent advances in human single-cell and spatial transcriptomic profiling have further revealed previously underappreciated macrophage heterogeneity, context-dependent activation states, and neuroimmune interactions within the limbal niche. To review current evidence on the localization, plasticity, and immuno-modulatory functions of corneal macrophages-with emphasis on human-derived insights, emerging neuroimmune mechanisms, and their interactions with LSCs during homeostasis and injury. This narrative review integrates findings from the immunology, stem cell biology, and ophthalmology literature. It focuses on macrophage-derived cytokines, metabolic mediators, and microenvironmental cues that influence LSC behavior, and incorporates recent human single-cell, spatial transcriptomic, and regenerative immunology studies as well as therapeutic strategies modulating macrophage phenotype. Macrophages exhibit dynamic and spectrum-like polarization during corneal inflammation and repair, extending beyond the traditional M1/M2 dichotomy. Their secreted factors-including TNF-α, IL-6, TGF-β, IL-10, and NO, and Arg1-derived metabolites-affect LSC proliferation, migration, and differentiation in a dose-, time-, and context-dependent manner. Therapeutic reprogramming of macrophages via pharmacological agents, stem cell-derived exosomes, α-MSH-based neuroimmune modulation, and bioactive compounds enhances corneal regeneration. Macrophages serve as pivotal modulators of the limbal niche. Targeting macrophage-stem cell crosstalk represents a promising avenue for restoring niche stability and preventing limbal stem cell deficiency. Future progress will rely on human single-cell atlases, immune microenvironment profiling, and macrophage-targeted immunoregenerative strategies.
2025-11-30 | Mechanistic insights into conjunctivalization in limbal stem cell deficiency using a lineage tracing approach.
Disease that develops on the ocular surface in animals and humans that have their limbal stem cells erased or their niche severely damaged by physical or chemical trauma, is difficult to visually evaluate in a progressive and long-term manner. When limbal stem cell deficiency (LSCD) develops under such circumstances, intravital clinical microscopy or other techniques cannot be used to accurately detail what transpires on the cornea. Here, we investigated the evolution of LSCD and characterize cellular transformations that arise when the limbal niche is lost. We employed the multi-color K14CreERT2-Confetti transgenic reporter mice (n = 51) to monitor LSCD in real-time, combined with proliferation markers and in vitro analyses to identify and characterize conjunctival epithelial transformations using wild-type C57BL/6 mice (n = 31). Conjunctival epithelia either spawn MUC5AC + goblet cells (GCs) or K12+ cornea-like epithelia. These cells arise from Ki67+ proliferating differentiated conjunctival squames as opposed to DNA label retaining conjunctival stem/progenitor cells. In vitro analyses suggests that GC metaplasia (GCM) and conjunctival transdifferentiation (CjTD) evolve from environmental stress and soluble keratocyte elaborated signals and corneal matrix-associated physical cues. GCM is a pathological process, as opposed to CjTD, which is the cornea's attempt to self-repair. The co-existence of two fundamentally diverse cellular interchanges establishes a medical conundrum in LSCD which may be resolved via pharmacological or biological intervention in conjunction with surgery to replenish the stem cell pool.
2025-06-12 | Stevens-Johnson Syndrome as a Risk Factor for Ocular Surface Squamous Neoplasia in a Pediatric Patient.
This report describes a rare case of ocular surface squamous neoplasia (OSSN) developing in the aftermath of Stevens-Johnson syndrome (SJS). A 15-year-old female patient, who had previously experienced an episode of SJS triggered by non-steroidal anti-inflammatory drugs (NSAIDs), developed limbal stem cell deficiency (LSCD) and was subsequently diagnosed with OSSN in the setting of chronic ocular surface inflammation. She was treated successfully with topical immunotherapy using interferon alpha-2b. This case highlights the pivotal role of chronic inflammation and immune dysregulation in driving neoplastic transformation of the ocular surface. In particular, severe immune-mediated disorders such as SJS can disrupt corneal homeostasis and establish a pro-oncogenic microenvironment that fosters dysplasia and neoplastic progression.
antibodies
2026-01-09 | Limbal Epithelial Stem Cells in Review: Immune and Lymphangiogenic Privilege and Their Clinical Relevance.
The cornea maintains transparency by preserving immune and (lymph)angiogenic privilege through active suppression of inflammation and vascular invasion, a process centrally regulated by limbal epithelial stem cells (LESCs) located at the corneoscleral junction. Beyond renewing the corneal epithelium, LESCs maintain immune and vascular balance via extracellular matrix interactions and paracrine signalling, exerting predominantly anti-inflammatory and anti-(lymph)angiogenic effects in vivo. Disruption of the limbal niche by trauma, UV exposure, or genetic disorders such as aniridia leads to limbal stem cell deficiency (LSCD), chronic inflammation, loss of corneal avascularity, and vision loss. The identification of ABCB5 as a key LESC marker has clarified functional limbal subsets, highlighting ABCB5+ epithelial cells as mediators of repair, remodelling, and immune suppression, and positioning them as promising therapeutic targets for treatments that restore both epithelial integrity and corneal immune privilege.
2024-12-03 | TNF-α Suppression Attenuates Limbal Stem Cell Damage in Ocular Injury.
Ocular chemical injuries often cause uveal inflammation, upregulation of TNF-α at the limbus, and subsequent limbal stem cell (LSC) damage. In this study, we investigate the protective role of TNF-α suppression in LSC survival. Corneal alkali injuries were performed using NaOH as previously described by our group. Anterior chamber pH elevation in the absence of corneal alkali exposure was achieved by cannulation. A CX3CR1 +/EGFP ::CCR2 +/RFP bone marrow chimera was used to study the role of innate immune cells in LSC damage, which was assessed by TUNEL assay, ABCB5, cytokeratin 12 and 13 staining, flow cytometry, in situ hybridization, and qPCR. Corneal neovascularization and conjunctivalization were evaluated by light microscopy. Intraperitoneal injection of 6.25 mg/kg infliximab was administered after irrigation. A TNFR1/2 knockout mouse was used to confirm the findings by a second method. Systemic administration of 6.25 mg/kg infliximab suppressed uveal inflammation after anterior chamber pH elevation or corneal alkali injury and led to reduction of TNF-α secreting CCR2 + and CX3CR1 + monocytes in the basal limbal tissue. In turn, this led to LSC survival ( P < 0.01) and allowed reestablishment of K12 + epithelium ( P < 0.05) on the injured cornea. Moreover, it led to less corneal neovascularization, conjunctivalization, and scarring, as compared with untreated animals. The protective effect of TNF-α suppression was confirmed in TNFR1/2 knockout mice. Prompt systemic administration of TNF-α inhibitor prevents LSC deficiency and facilitates corneal reepithelialization after alkali burn. TNF-α suppression may benefit the outcomes of other ocular injuries that cause LSC deficiency.
2023-06-13 | The Reliability of PCL/Anti-VEGF Electrospun Scaffolds to Support Limbal Stem Cells for Corneal Repair
Since only few reported studies propose anti-vascular endothelial growth factor (anti-VEGF) delivery through electrospun scaffolds, this study greatly contributes to the potential prevention of patient's vision loss, as it explores electrospun polycaprolactone (PCL) coated with anti-VEGF for the blockage of abnormal cornea vascularization. In terms of physicochemical properties, the biological component increased the PCL scaffold fiber diameter (by ~24%) and pore area (by ~82%), while ut slightly reduced its total porosity as the anti-VEGF solution filled the voids of the microfibrous structure. The addition of the anti-VEGF increased the scaffold stiffness almost three-fold at both strains of 5 and 10%, as well as its biodegradation rate (~36% after 60 days) with a sustained release profile after Day 4 of phosphate buffered saline incubation. In terms of scaffold application function, the PCL/Anti-VEGF scaffold proved to be more favorable for the adhesion of cultured limbal stem cells (LSCs); this was confirmed by the SEM images, where the cells showed flat and elongated conformations. Further support of the LSC growth and proliferation was confirmed by the identified p63 and CK3 markers after cell staining. These results demonstrate the advantageous effect of the surface-adsorbed anti-VEGF to stop vision loss and help damaged corneal tissue repair.
2023-05-08 | Refractory Keratolimbal Allograft Rejection in Autoimmune Polyglandular Syndrome-Associated Keratopathy Treated With Intravenous Immunoglobulin.
The aim of this study was to describe the use of intravenous immunoglobulin (IVIG) in the management of a 20-year-old woman with autoimmune polyglandular syndrome-associated keratopathy who developed acute transplant rejection after keratolimbal allograft (KLAL) surgery. Nine weeks after KLAL surgery, a 20-year-old woman with autoimmune polyglandular syndrome-related limbal stem cell deficiency presented with graft injection, hemorrhage, and an epithelial rejection line. This was concerning for acute rejection in the setting of triple-agent systemic immunosuppression (albeit nonadherence at times). There was initial reversal of the rejection process with a sub-Tenon's injection of triamcinolone, frequent topical corticosteroids, increase in oral prednisone, and optimization of systemic immunosuppression medications; however, recurrence of the epithelial rejection line and symptoms were noted whenever the prednisone dose was tapered. This was accompanied by ocular surface decompensation (late staining, neovascularization, and persistent epithelial defects). She was found to have weakly positive HLA Class 1 antibodies. The patient was treated with a pulsed corticosteroid infusion and 2 monthly IVIG infusions. This led to resolution of the acute rejection. However, there was a subsequent rejection episode 4 months later after tapering the prednisone. Monthly IVIG for 6 more months led to final resolution with successful prednisone tapering and no further rejection. Treatment with prolonged IVIG showed better improvement in a case of acute rejection refractory to traditional treatments, especially in the setting of HLA antibodies. The case demonstrates that close follow-up with a corneal specialist and collaboration with a transplant specialist is important to monitor for postoperative KLAL rejection.
2023-01-17 | Outcomes of keratolimbal allograft from ABO compatible donors for severe bilateral limbal stem cell deficiency.
To report outcomes of keratolimbal allograft (KLAL) compatible for both human leukocyte (HLA) and/or blood type using oral prednisone, mycophenolate, and tacrolimus, with basiliximab if panel reactive antibodies (PRA) are present. Intravenous immunoglobulin (IVIG) was used post-operatively if donor-specific anti-HLA antibodies (DSA) were present. Retrospective interventional series of consecutive patients with KLAL for limbal stem cell deficiency (LSCD) from HLA and/or blood type compatible deceased donors with a minimum follow-up time of 12 months. Main outcome measures were ocular surface stability, visual acuity and systemic immunosuppression (SI) adverse events. Eight eyes of eight patients with mean age of 48.6 ± 10.1 years (range 34-65 years) were included. Mean follow-up time was 37.3 ± 22.7 months (range 12-71 months) following KLAL; four (50%) had combined LR-CLAL surgery. The etiologies of LSCD were Stevens-Johnson Syndrome (n = 4/8), aniridia (n = 2/8), chemical injury (n = 1/8) and atopic eye disease (n = 1/8). All patients had PRA present and received basiliximab infusions. 5/8 patients received IVIG based on DSA identified pre-operatively. At last follow-up, 7 eyes (87.5%) had a stable ocular surface; 1 eye (12.5%) developed failure and had keratoprosthesis implantation. There was a significant improvement in visual acuity from 1.65 ± 0.48 to 0.68 ± 0.34 logMAR (p = 0.01). SI was tolerated well with minimal adverse events. Preliminary outcomes of KLAL with ABO compatible tissue using the Cincinnati protocol, preoperative basiliximab (when PRA present) and post-operative IVIG (when DSA present) are encouraging. This protocol may allow for utilization of deceased donor tissue with results approximating those of living donor tissue transplanted for severe bilateral LSCD.
other
2026-02-11 | Selective Disruption of Mutant TP63 Alleles Restores Corneal Epithelial proliferation in EEC Syndrome
Abstract Ectrodactyly–Ectodermal Dysplasia–Cleft Lip/Palate (EEC) syndrome is a rare disorder caused by dominant-negative mutations in the TP63 gene, frequently leading to limbal stem cell deficiency (LSCD) and progressive corneal degeneration. Current therapeutic strategies are limited, primarily due to impaired epithelial renewal and poor proliferative capacity of patient-derived cells. We have recently shown that decreasing the expression of the mutated allele by means of siRNA-mediated silencing can restore epithelial cell proliferation. However, the clinical utility of this approach is hindered by the presence of different TP63 mutations causing EEC syndrome, and the need for continuous siRNA administration to achieve sustained gene silencing. To address these challenges, we employed a CRISPR/Cas9-based genome editing strategy to disrupt mutant TP63 alleles in human induced pluripotent stem cells (hiPSCs) derived from EEC patients carrying R279H and R304Q mutations. Targeted editing of exon 6 induced frameshift mutations that activated nonsense-mediated mRNA decay, leading to a significant reduction in mutant transcript levels. Edited hiPSC-derived corneal epithelial cells exhibited improved cell proliferation compared to unedited isogenic controls. These findings demonstrate the feasibility and therapeutic potential of allele-specific genome editing to correct TP63-associated epithelial defects in EEC syndrome paving the way toward future regenerative therapies for TP63-related corneal diseases.
2024-09-24 | Limbal Stem Cell Deficiency After Treatment of Ocular Surface Squamous Neoplasia.
To investigate limbal stem cell deficiency (LSCD) in patients surgically treated for ocular surface squamous neoplasia (OSSN). This retrospective case-control study investigated clinical and histological data from patients with OSSN surgically treated in a referral center. The study included 98 patients (58 male, 40 female) with a mean age of 61.1 (23-86) years. Less than 3 clock hours were involved by OSSN in 48 eyes (49.0%), 3-6 clock hours in 32 eyes (32.7%), 6-9 clock hours in 12 eyes (12.2%), and more than 9 clock hours in 6 eyes (6.1%). Limbal stem cell deficiency was identified in 36 patients (36.7%) after surgery. The severity of LSCD was mild in 17 eyes, moderate in 11, and severe in 8. The prevalence of LSCD increased significantly in groups with 6 clock hours or more of OSSN involvement ( p < 0.001). The affected limbal side (superior, inferior, nasal, or temporal) had no significant association with the prevalence of LSCD ( p = 0.869). Patients with recurrent OSSN had a higher LSCD prevalence ( p = 0.003). The higher the tumor stage, the more likely it was to develop LSCD ( p < 0.001). Patients with corneal involvement were also more likely to develop LSCD ( p = 0.021). The prevalence of LSCD was raised with increasing histopathological grade ( p = 0.019). Furthermore, solely the number of clock hours affected by OSSN was an independent risk factor in multivariate analyses ( p < 0.001). The size and severity of OSSN and the presence of recurrent OSSN are associated with an increased likelihood of developing LSCD. Furthermore, the extent of the limbal area involved by the OSSN is identified as an independent risk factor of the development of LSCD.
2024-04-11 | Sox9 marks limbal stem cells and is required for asymmetric cell fate switch in the corneal epithelium
Adult tissues with high cellular turnover require a balance between stem cell renewal and differentiation, yet the mechanisms underlying this equilibrium are unclear. The cornea exhibits a polarized lateral flow of progenitors from the peripheral stem cell niche to the center; attributed to differences in cellular fate. To identify genes that are critical for regulating the asymmetric fates of limbal stem cells and their transient amplified progeny in the central cornea, we utilized an in vivo cell cycle reporter to isolate proliferating basal cells across the anterior ocular surface epithelium and performed single-cell transcriptional analysis. This strategy greatly increased the resolution and revealed distinct basal cell identities with unique expression profiles of structural genes and transcription factors. We focused on Sox9; a transcription factor implicated in stem cell regulation across various organs. Sox9 was found to be differentially expressed between limbal stem cells and their progeny in the central corneal. Lineage tracing analysis confirmed that Sox9 marks long-lived limbal stem cells and conditional deletion led to abnormal differentiation and squamous metaplasia in the central cornea. These data suggest a requirement for Sox9 for the switch to asymmetric fate and commitment toward differentiation, as transient cells exit the limbal niche. By inhibiting terminal differentiation of corneal progenitors and forcing them into perpetual symmetric divisions, we replicated the Sox9 loss-of-function phenotype. Our findings reveal an essential role for Sox9 for the spatial regulation of asymmetric fate in the corneal epithelium that is required to sustain tissue homeostasis.
2024-03-01 | Different Types of Therapies in Corneal Regeneration
The ocular surface is the outermost part of the visual system can experience physical or chemical damage from external or internal factors such as thermal harm, infectious pathogens, and burns, Steven Johnson Syndrome or, other autoimmune diseases.Limbal cells possess stem cell qualities and regenerative capabilities due to their capacity for differentiation.The regeneration of corneal wounds involves a multifaceted process encompassing cell death, proliferation, migration, differentiation, and remodeling of the extracellular matrix.Among various therapies for corneal regeneration, stem cell therapy stands out as the most promising due to its rapid recovery from infections.Although still in its early stages, interventions for treating corneal abnormalities are underway.These interventions involve the use of both viral and non-viral vectors to introduce genes into the cornea, employing in vivo, ex vivo, and in vitro methods.This review primarily focuses on the latest advancements utilizing biological modulators like gene therapy, signaling inhibitors, microRNA, and Nano formulations.Additionally, the paper concentrates on the latest therapies utilizing stem cells and advancements in the ocular drug delivery system, aiming to enhance potential therapies for the future treatment of ocular diseases.
2023-08-28 | FoxC1 activates limbal epithelial stem cells following corneal epithelial debridement.
Limbal epithelial stem cells are not only critical for corneal epithelial homeostasis but also have the capacity to change from a relatively quiescent mitotic phenotype to a rapidly proliferating cell in response to population depletion following corneal epithelial wounding. Pax6+/- mice display many abnormalities including corneal vascularization and these aberrations are consistent with a limbal stem cell deficiency (LSCD) phenotype. FoxC1 has an inhibitory effect on corneal avascularity and a positive role in stem cell maintenance in many tissues. However, the role of FoxC1 in limbal epithelial stem cells remains unknown. To unravel FoxC1's role(s) in limbal epithelial stem cell homeostasis, we utilized an adeno-associated virus (AAV) vector to topically deliver human FOXC1 proteins into Pax6 +/- mouse limbal epithelium. Under unperturbed conditions, overexpression of FOXC1 in the limbal epithelium had little significant change in differentiation (PAI-2, Krt12) and proliferation (BrdU, Ki67). Conversely, such overexpression resulted in a marked increase in the expression of putative limbal epithelial stem cell markers, N-cadherin and Lrig1. After corneal injuries in Pax6 +/- mice, FOXC1 overexpression enhanced the behavior of limbal epithelial stem cells from quiescence to a highly proliferative status. Overall, the treatment of AAV8-FOXC1 may be beneficial to the function of limbal epithelial stem cells in the context of a deficiency of Pax6 function.
cell therapies
2026-09-09 | 3D Culture Reverses Limbal Niche Cell Replicative Aging via FOSL1 Upregulation.
Limbal niche cells (LNCs) serve as essential regulators of limbal microenvironmental homeostasis and corneal epithelial wound repair, representing a promising therapeutic resource for limbal stem cell deficiency (LSCD). However, their clinical application is constrained by replicative aging during in vitro expansion. In this study, we investigated whether a three-dimensional (3D) Matrigel-based culture system could modulate replicative aging in LNCs. Compared with conventional two-dimensional (2D) culture, 3D-cultured LNCs restored stemness marker expression and enhanced proliferative capacity. Concurrently, these cells displayed reduced senescence-associated β-galactosidase (SA-β-gal) activity and decreased expression of senescence-associated proteins, including p16, p21, p53, and γ-H2AX. Single-cell RNA sequencing (scRNA-seq) analysis revealed prominent upregulation of FOS-like antigen 1 (FOSL1). FOSL1 is a component of the AP-1 transcription factor family and participates in cell proliferation and stress adaptation. Functional assays using an in vitro replicative aging model showed that FOSL1 knockdown in early-passage (P4) LNCs accelerated senescence, whereas FOSL1 overexpression in late-passage (P11) LNCs attenuated senescence. Mechanistically, FOSL1 knockdown induced mitochondrial dysfunction characterized by elevated levels of mitochondrial superoxide and cellular reactive oxygen species (ROS), as well as a decrease in mitochondrial membrane potential, while FOSL1 overexpression preserved mitochondrial integrity and function. Collectively, our findings demonstrate that 3D culture reverses LNC replicative aging through FOSL1-mediated enhancement of mitochondrial function, providing a microenvironment-based strategy to counteract replicative aging in adult stem cells for corneal regenerative therapy.
2026-08-29 | Safety and tolerability of topical mesenchymal stromal cell secretome in persistent corneal epithelial disease-a phase 1b clinical trial.
To investigate the safety and tolerability of a topical allogeneic bone marrow-derived mesenchymal stromal cell (BM-MSC) secretome in chronic corneal epithelial disease. A prospective single-center, uncontrolled, open-label phase 1b clinical trial was conducted.A dose escalation study design was used. Participants were patients with persistent corneal epithelial disease in the setting of neurotrophic keratitis and/or limbal stem cell deficiency.The first 3 participants were treated with topical BM-MSC secretome in 1 eye twice daily, the next 3 participants received the treatment 4 times a day, and the last 3 received it 6 times a day for 28 days. The primary outcomes were safety and the maximum tolerated dose (MTD) of the topical BM-MSC secretome. Ocular surface toxicity and other ocular or systemic treatment-emergent adverse events were assessed up to 90 days. Demonstration of safety on day 28 was required for each dosing frequency group before escalating to the next higher dose. A total of 9 participants were enrolled. No dose-limiting toxicities (DLTs) were observed in the 6 patients who received the BM-MSC secretome 2 or 4 times a day. Two of the 3 participants who were treated 6 times a day developed reversible DLTs, including a new corneal epithelial defect and increased central corneal staining with a consequent transient reduction in best-corrected visual acuity (BCVA). Potential signals of clinical efficacy were observed, particularly in the BCVA and corneal sensation in the majority of participants who completed the treatment. Topical BM-MSC secretome 2 or 4 times a day for 28 days was safe and well tolerated without signs of systemic or ocular toxicity in persistent corneal epithelial disease.
2026-08-24 | Eight-Year Outcomes of Staged Penetrating Keratoplasty After Simple Limbal Epithelial Transplantation in Ocular Surface Burns: A Case Report.
The purpose of this article was to report long-term outcomes of staged simple limbal epithelial transplantation (SLET) followed by penetrating keratoplasty (PKP) in patients with severe ocular surface burns. Two patients with unilateral severe ocular surface burns and limbal stem cell deficiency (LSCD) underwent SLET performed by a single surgeon. After ocular surface stabilization, sequential PKP combined with cataract extraction and posterior chamber intraocular lens implantation was performed. Patients were followed for 8 years. Anatomical success (stable, epithelized surface, and clear graft) and functional outcomes (best-corrected visual acuity) were assessed. Both eyes achieved sustained ocular surface stability before keratoplasty. At 8 years, clear grafts with stable epithelium were maintained in both cases. Final best-corrected visual acuity was 20/20 (with contact lens) and 20/120, respectively. No episodes of graft rejection, persistent epithelial defects, or vision-threatening complications were observed during follow-up. A staged approach with SLET followed by PKP may provide favorable long-term anatomical and visual outcomes in selected patients with severe ocular surface burns and LSCD. Larger studies are needed to validate these findings.
2026-08-09 | State-of-the-art advances in tissue-engineered corneal substitutes: a systematic review (2020-2025).
Corneal blindness remains a major global health burden, limited by donor shortage and graft-related complications. Tissue-engineered corneal substitutes have emerged as a promising alternative, aiming to restore corneal structure and function through bioengineered constructs. To systematically review recent advances (2020-2025) in tissue-engineered corneal substitutes, classifying them according to the corneal layer replaced and evaluating their biological, optical, and functional performance, as well as their translational potential for clinical application. A systematic review. A systematic review was conducted following Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) 2020 guidelines. Searches were performed in PubMed/MEDLINE, Scopus, and Web of Science using predefined keywords related to corneal tissue engineering. Eligible studies included experimental, preclinical, or clinical studies published between January 2020 and June 2025 describing cell-based corneal substitutes. Studies focused on keratoprostheses (KPros), acellular scaffolds, or non-cellular biomaterials were excluded. Fourteen studies met the inclusion criteria: five endothelial, three stromal, one epithelial, and five epithelium-stroma substitutes. Endothelial models demonstrated cell viability, expression of tight junction proteins (ZO-1, Na+/K+-ATPase), and partial restoration of corneal transparency in animal and ex vivo systems. Stromal models incorporated advanced biofabrication techniques such as 3D bioprinting and neuronal co-culture, achieving > 80% optical transmittance and adequate biomechanical properties. The single epithelial model achieved complete re-epithelialization in a rabbit limbal deficiency model. Multilayered epithelium-stroma substitutes, including the NANOULCOR (Tissue Engineering Group, University of Granada, Granada, Spain) construct, exhibited safety and feasibility in preclinical and early clinical studies. Recent progress in corneal tissue engineering has yielded increasingly functional and biocompatible substitutes that replicate native corneal architecture. However, most studies remain limited by small sample sizes, short follow-up, and reliance on animal models. Further standardized clinical trials are required for clinical translation. Not applicable.
2026-08-04 | Refining How We Diagnose and Classify Limbal Stem Cell deficiency.
Refining How We Diagnose and Classify Limbal Stem Cell deficiency CLINICAL RELEVANCE: With the development of multimodal anterior segment imaging modalities and molecular diagnostic tests for the diagnosis and staging of limbal stem cell deficiency (LSCD), and better understanding of LSCD presentation and pathophysiology, a comprehensive step-by-step algorithm is established to more precisely evaluate the ocular surface environment and stage the disease. This is a review of the most relevant publications on the method of diagnosing and staging LSCD. Clinical presentation and pathophysiology of LSCD were reviewed. Factors that impact LSC function and survival were discussed and outlined. The International LSCD Working Group has put forth the first guidelines on the clinical definition, classification, diagnosis, staging, and management of LSCD. Precise diagnosis and staging of LSCD is limited by subjective nature of the fluorescein staining test. As other comorbidities negatively impact the function of both corneal epithelial cells and LSCs, assessment of these comorbidities such as dry eye disease, ocular surface inflammation, corneal innervation, conjunctival health, medication toxicity, and eyelid abnormalities should be included in the initial evaluation of LSC function. Advances in anterior segment imaging, including anterior segment optical coherence tomography and in vivo confocal microscopy allow objective evaluation of epithelial phenotype, cellular morphology, basal cell density, corneal innervation, and inflammatory cell infiltration in both the cornea and limbus. The knowledge of ocular surface microstructure provides important information regarding the corneal and limbal epithelial cell function, remaining LSC reserve, and factors associated with LSCD improvement after all comorbidities are treated. Impression cytology remains a valuable tool for objectively confirming conjunctivalization through assessment of epithelial phenotype. LSCD diagnosis and classification have advanced beyond the simple fluorescein staining test for the detection of abnormal epithelial cells on the corneal surface. A comprehensive assessment of the LSC function and the ocular surface environment by integrating multimodal imaging and molecular testing enables precise staging of LSC function and identification of factors that influence LSCD reversibility. Adoption of a standardized multimodal diagnostic framework will improve diagnostic accuracy, guide the management of the disease, facilitate comparisons across clinical studies, and support the development and evaluation of emerging cell-based and cell-free regenerative therapies for LSCD.
small molecules
2026-09-22 | Effect of Combined Rebamipide and Cyclosporine Therapy in Limbal Stem Cell Deficiency Caused by Long-term Soft Contact Lens Wear
Purpose: To evaluate the clinical outcomes of combined aggressive nonsurgical treatments, including combined rebamipide and cyclosporine therapy, in patients with stage IIb limbal stem cell deficiency (LSCD) induced by long-term silicone hydrogel contact lens wear.Methods: A retrospective case series analysis was conducted on four eyes of three patients with stage IIb LSCD with a history of prolonged contact lens wear, who were refractory to artificial tears and other conventional conservative treatments for at least 1 month. Contact lens use was discontinued in all the patients, and topical rebamipide and cyclosporine were administered in combination. Changes in the best-corrected visual acuity, corneal epithelial stability, degree of corneal conjunctivalization, and superficial corneal neovascularization were evaluated before and after treatment.Results: All patients demonstrated improved corneal epithelial stability after combination therapy. The progression of corneal epithelial opacity and conjunctivalization was suppressed, and a marked improvement in visual acuity was observed in some cases. No significant drug-related adverse events were observed during the treatment period.Conclusions: Aggressive nonsurgical treatment, including combined topical therapy with rebamipide and cyclosporine, topical steroids, and supportive treatment, may be an effective treatment option for patients with stage IIb contact lens–induced LSCD who are unresponsive to artificial tear–based conservative management. This strategy may be considered before surgical intervention in selected patients with stage IIb LSCD in whom the residual limbal function is preserved.
2026-09-16 | Corticosteroid-Sparing Systemic Immunosuppression for Ocular Surface Stem Cell Transplantation.
The goal of our study was to highlight the results of a corticosteroid-sparing immunosuppressive regimen for patients with limbal stem cell deficiency (LSCD) undergoing ocular surface stem cell transplantation (OSST). This retrospective review studied patients with LSCD undergoing OSST from 2014 to 2023, evaluating the evolving corticosteroid-sparing systemic immunosuppression regimen over time. Inclusion criteria encompassed patients aged 18 to 69 with total/near-total LSCD that underwent OSST and were treated postoperatively with oral corticosteroids. Outcomes included ocular surface stability, visual acuity, and rates of rejection/failure. Corticosteroid dosage, taper length, and corticosteroid-related side effects were recorded. There were 166 eyes that met the inclusion criteria. The mean starting dose of prednisone was 34.5 mg (range: 30-60), with a mean taper length of 13.3 weeks (range: 3-59 weeks). There were 66 eyes that underwent a keratolimbal allograft, 96 eyes that underwent a living-related conjunctival limbal allograft, and 28 eyes that underwent a conjunctival limbal autograft. At the last follow-up, 72.3% of eyes had a stable ocular surface and 60.2% had visual improvement of at least 2 lines. Approximately 19.9% of eyes developed rejection and 13.3% developed failure during the follow-up period. A modified corticosteroid-sparing immunosuppression protocol for OSST has shown significant efficacy in restoring the ocular surface of patients with LSCD. A corticosteroid-sparing immunosuppressive regimen mitigates the side effects related to oral corticosteroid usage, without compromising the stability of the stem cell graft.
2026-07-29 | Enhancing the Outgrowth of Oral Mucosal Cell Sheets for Cultivated Rabbit Oral Mucosal Epithelial Transplantation with ROCK Inhibitor.
Cultivated oral mucosal epithelial transplantation (COMET) is an effective way to treat limbal stem cell deficiency (LSCD), but its clinical usage is limited due to prolonged cultivation time and complexity. Rho-associated protein kinase (ROCK) inhibitors have been found to enhance cell proliferation, migration, and cytoskeleton maintenance. We investigated whether ROCK inhibitor (Y-27632) can be used to enhance the growth of oral mucosal epithelial cell sheet while remaining their characteristics, optimizing COMET usage for LSCD treatment. Oral mucosal epithelial cells were harvested from rabbits and cultured using a collagenase-based isolation technique. Cells were seeded in a transwell plate with or without amniotic membrane (AM) and Y-27632. The speed of cell sheet outgrowth and cell density were evaluated. Stem cell marker (p63), cytokeratin (K3, K4 and K13) and junctional protein markers (ZO-1, occludin, connexin 43) were analyzed by immunostaining with confocal microscopy. Y-27632 and AM coating facilitated the outgrowth of cell sheets, resulting in a larger expansion area from day 7 to day 15 (p < 0.05). Y-27632 treatment dose-dependently increased basal cell density (p < 0.05) and inhibited the squamous differentiation of the superficial layer, while maintaining cytokeratin and junctional protein markers expression. Y-27632 increased the p63-positive cells population (p < 0.05), which may play a role in maintaining stem cell properties and inhibiting differentiation. Y-27632, together with AM, provides an efficient and supportive environment for producing oral mucosal epithelial cell sheets for transplantation. They might serve as an adjunctive agent to accelerate oral epithelial cell-based therapy for the treatment of limbal stem cell deficiency.
2026-06-30 | 3% diquafosol sodium combined with 0.1% fluorometholone for postoperative dry eye in pterygium patients with preoperative tear deficiency: a pilot retrospective study
Background To evaluate the clinical efficacy and safety of 3% diquafosol sodium combined with 0.1% fluorometholone for postoperative dry eye in pterygium patients with preoperative tear deficiency. Methods This single-center retrospective study included 82 pterygium patients (82 eyes) with preoperative tear deficiency who underwent pterygium excision combined with limbal stem cell transplantation. Patients were divided into an observation group (diquafosol + fluorometholone, n = 42) and a control group (sodium hyaluronate + fluorometholone, n = 40). Tear break-up time (BUT), corneal fluorescein staining (CFS) score, Ocular Surface Disease Index (OSDI), Schirmer I test (SIt), and intraocular pressure (IOP) were assessed preoperatively and at 2 and 4 weeks postoperatively. Adverse events and complications were recorded. Results Eighty patients completed follow-up (41 in observation group, 39 in control group). At 4 weeks postoperatively, the observation group showed significantly longer BUT, lower CFS and OSDI scores, and higher SIt values compared to the control group (all p < 0.05). No significant intergroup differences in IOP were observed at any time point. Transient ocular stinging occurred in 2 patients (4.88%) in the observation group, with no severe complications in either group. Conclusion In this pilot study, the combination of 3% diquafosol sodium and 0.1% fluorometholone showed preliminary evidence of improving tear film stability, repairing ocular surface damage, and alleviating dry eye symptoms in pterygium patients with preoperative tear deficiency, without significantly affecting IOP. Its efficacy appeared superior to sodium hyaluronate combined with fluorometholone. These findings support further investigation in larger, longer-term randomized controlled trials.
2026-05-29 | Lactate-fueled H3K18 lactylation sustains ΔNp63α-dependent self-renewal in limbal epithelial stem cells.
The interplay between metabolic reprogramming and epigenetic regulation in controlling stem cell fate remains incompletely understood, particularly in limbal epithelial stem cells (LESCs) that are essential for corneal homeostasis. Here, we identify glycolytic lactate as a critical metabolic regulator that sustains LESC self-renewal through an epigenetic mechanism. We established a progenitor-like LESC model via MYC overexpression (oeMYC-LESCs). Using CUT&Tag, RNA-seq, and a mouse corneal epithelial injury model, we found that oeMYC-LESCs exhibit enhanced glycolysis and lactate efflux, which fueled p300/CBP-mediated histone lactylation, especially histone H3 lysine 18 lactylation (H3K18la). Enrichment of H3K18la at the ΔNp63α promoter drives its transcriptional activation, thereby sustaining LESC self-renewal. Inhibition of lactate generation depleted H3K18la, suppressed ΔNp63α, and consequently impaired LESC function; notably, these phenotypes were partially rescued by exogenous lactate supplementation. In vivo experiments confirmed that lactate accelerates corneal re-epithelialization and upregulates ΔNp63α in an H3K18la-dependent manner, whereas pharmacological blockade of lactate production delayed wound healing. Collectively, our study reveals a lactate-H3K18la-ΔNp63α axis as a key metabolic-epigenetic-transcriptional mechanism sustaining LESC self-renewal, suggesting a novel therapeutic target for treating limbal stem cell deficiency.
proteins
2026-05-27 | A Novel Selective Strategy for Bioactive Limbal Stem Cells Primary Culture Using Deep Cryopreservation and IL-1β Precondition.
Limbal stem cell (LSC) transplantation is an important treatment for limbal stem cell deficiency (LSCD), but low efficacy in maintaining LSC stemness during in vitro expansion greatly affects its wider application. The primary contributing factors include a low proportion of stem cells and the lack of a stable, supportive microenvironment over prolonged culture. Rabbit corneal tissues preserved under deep cryogenic conditions for more than six months retain viable limbal stem cells (LSCs), and primary LSCs isolated from these tissues exhibit robust stem cell characteristics. It is noteworthy that the NLRP3/Caspase-1/IL-1β signaling axis was activated in corneal epithelial cells, and outer limbal layers preserved for one or two years. Based on these findings, a combined strategy integrating deep cryopreservation with IL-1β induction was established for the processing of limbal tissues. The combined cryogenic and IL-1β preconditioning yielded primary LSCs with maintained p63+ cell proportions, a reduction in K3+ differentiated cells from approximately 80% to 60%, and a 6.25-fold increase in colony-forming efficiency. In addition, an increased proportion of cells in the G2/M phase and enhanced proliferative capacity were observed. The enriched LSC population also exhibited improved stratified epithelial reconstruction potential. These findings identify an effective strategy for preserving and enriching LSCs from limbal tissue, providing a practical and efficient approach for LSC preparation prior to transplantation. Further in vivo studies will be important to validate the functional performance of these cells in ocular surface reconstruction.
2026-01-31 | Association Between Neurotrophic Keratitis and Limbal Stem Cell Deficiency.
To investigate changes in corneal nerves, immune cells, and limbal epithelial stem cells (LESCs) in neurotrophic keratitis (NK) patients; to analyze correlations between these parameters and clinical manifestations; and to monitor long-term corneal changes in NK patients receiving recombinant human nerve growth factor (rh-NGF). Cross-sectional study with an interventional case series. A total of 54 NK patients (55 eyes) and 57 healthy controls (59 eyes) were enrolled. In vivo confocal microscopy (IVCM) was performed to evaluate subbasal nerve fiber parameters, density of limbal epithelial stem cells (LESCs) in different directions, and dendritic cell (DC) status. Longitudinal changes in these parameters are recorded at baseline, weeks 4 and 8, and the 2-year follow-up in the rh-NGF-treated subgroup (7 eyes of 7 patients). Correlation analyses are conducted among all parameters in the NK group. In patients with neurotrophic keratopathy (NK), corneal nerve fiber density (CNFD) (P < .01), nerve fiber length (CNFL) (P < .01), and nerve branch density (CNBD) (P < .01) were significantly less than in healthy controls. Similarly, central BCD (P < .001) and peripheral LESCs density (P < .001) were markedly lower in NK group. In contrast, DCs density (P < .001) and activation ratio (P < .001) of patients with NK were higher. Correlation analyses revealed that CNFD was positively correlated with LESCs density (ρ = 0.46; P < .001), and negatively correlated with fluorescein staining scores (ρ = -0.46; P < .001) and DC density (ρ = -0.57; P < .001). LESC density was negatively correlated with both fluorescein staining scores (ρ = -0.62; P < .001) and mean DC area (ρ = -0.44; P < .001), whereas fluorescein staining scores were positively correlated with DC density (ρ = 0.44; P < .001). Compared with baseline, improvements in LESC density, DC density, activation, and fluorescein staining scores became observed at 4 weeks of rh-NGF treatment, whereas nerve regeneration became detectable after 8 weeks and showed significant recovery by year 2. This study demonstrates that patients with NK exhibit corneal nerve damage, limbal stem cell deficiency, and immune cell activation, with significant correlations observed among these alterations. Short-term treatment with rh-NGF may initiate corneal recovery by first improving the limbal microenvironment and modulating immune responses, thereby promoting a regenerative feedback loop that supports sustained nerve regeneration and epithelial repair.
2026-01-19 | Corneal macrophages and limbal stem cells: emerging roles in ocular surface regeneration.
Corneal integrity and visual acuity rely on limbal stem cells (LSCs) and immune homeostasis. Macrophages, as critical immune regulators, are increasingly recognized for their roles in stem cell niche maintenance and tissue regeneration. Recent advances in human single-cell and spatial transcriptomic profiling have further revealed previously underappreciated macrophage heterogeneity, context-dependent activation states, and neuroimmune interactions within the limbal niche. To review current evidence on the localization, plasticity, and immuno-modulatory functions of corneal macrophages-with emphasis on human-derived insights, emerging neuroimmune mechanisms, and their interactions with LSCs during homeostasis and injury. This narrative review integrates findings from the immunology, stem cell biology, and ophthalmology literature. It focuses on macrophage-derived cytokines, metabolic mediators, and microenvironmental cues that influence LSC behavior, and incorporates recent human single-cell, spatial transcriptomic, and regenerative immunology studies as well as therapeutic strategies modulating macrophage phenotype. Macrophages exhibit dynamic and spectrum-like polarization during corneal inflammation and repair, extending beyond the traditional M1/M2 dichotomy. Their secreted factors-including TNF-α, IL-6, TGF-β, IL-10, and NO, and Arg1-derived metabolites-affect LSC proliferation, migration, and differentiation in a dose-, time-, and context-dependent manner. Therapeutic reprogramming of macrophages via pharmacological agents, stem cell-derived exosomes, α-MSH-based neuroimmune modulation, and bioactive compounds enhances corneal regeneration. Macrophages serve as pivotal modulators of the limbal niche. Targeting macrophage-stem cell crosstalk represents a promising avenue for restoring niche stability and preventing limbal stem cell deficiency. Future progress will rely on human single-cell atlases, immune microenvironment profiling, and macrophage-targeted immunoregenerative strategies.
2025-11-30 | Mechanistic insights into conjunctivalization in limbal stem cell deficiency using a lineage tracing approach.
Disease that develops on the ocular surface in animals and humans that have their limbal stem cells erased or their niche severely damaged by physical or chemical trauma, is difficult to visually evaluate in a progressive and long-term manner. When limbal stem cell deficiency (LSCD) develops under such circumstances, intravital clinical microscopy or other techniques cannot be used to accurately detail what transpires on the cornea. Here, we investigated the evolution of LSCD and characterize cellular transformations that arise when the limbal niche is lost. We employed the multi-color K14CreERT2-Confetti transgenic reporter mice (n = 51) to monitor LSCD in real-time, combined with proliferation markers and in vitro analyses to identify and characterize conjunctival epithelial transformations using wild-type C57BL/6 mice (n = 31). Conjunctival epithelia either spawn MUC5AC + goblet cells (GCs) or K12+ cornea-like epithelia. These cells arise from Ki67+ proliferating differentiated conjunctival squames as opposed to DNA label retaining conjunctival stem/progenitor cells. In vitro analyses suggests that GC metaplasia (GCM) and conjunctival transdifferentiation (CjTD) evolve from environmental stress and soluble keratocyte elaborated signals and corneal matrix-associated physical cues. GCM is a pathological process, as opposed to CjTD, which is the cornea's attempt to self-repair. The co-existence of two fundamentally diverse cellular interchanges establishes a medical conundrum in LSCD which may be resolved via pharmacological or biological intervention in conjunction with surgery to replenish the stem cell pool.
2025-06-12 | Stevens-Johnson Syndrome as a Risk Factor for Ocular Surface Squamous Neoplasia in a Pediatric Patient.
This report describes a rare case of ocular surface squamous neoplasia (OSSN) developing in the aftermath of Stevens-Johnson syndrome (SJS). A 15-year-old female patient, who had previously experienced an episode of SJS triggered by non-steroidal anti-inflammatory drugs (NSAIDs), developed limbal stem cell deficiency (LSCD) and was subsequently diagnosed with OSSN in the setting of chronic ocular surface inflammation. She was treated successfully with topical immunotherapy using interferon alpha-2b. This case highlights the pivotal role of chronic inflammation and immune dysregulation in driving neoplastic transformation of the ocular surface. In particular, severe immune-mediated disorders such as SJS can disrupt corneal homeostasis and establish a pro-oncogenic microenvironment that fosters dysplasia and neoplastic progression.
antibodies
2026-01-09 | Limbal Epithelial Stem Cells in Review: Immune and Lymphangiogenic Privilege and Their Clinical Relevance.
The cornea maintains transparency by preserving immune and (lymph)angiogenic privilege through active suppression of inflammation and vascular invasion, a process centrally regulated by limbal epithelial stem cells (LESCs) located at the corneoscleral junction. Beyond renewing the corneal epithelium, LESCs maintain immune and vascular balance via extracellular matrix interactions and paracrine signalling, exerting predominantly anti-inflammatory and anti-(lymph)angiogenic effects in vivo. Disruption of the limbal niche by trauma, UV exposure, or genetic disorders such as aniridia leads to limbal stem cell deficiency (LSCD), chronic inflammation, loss of corneal avascularity, and vision loss. The identification of ABCB5 as a key LESC marker has clarified functional limbal subsets, highlighting ABCB5+ epithelial cells as mediators of repair, remodelling, and immune suppression, and positioning them as promising therapeutic targets for treatments that restore both epithelial integrity and corneal immune privilege.
2024-12-03 | TNF-α Suppression Attenuates Limbal Stem Cell Damage in Ocular Injury.
Ocular chemical injuries often cause uveal inflammation, upregulation of TNF-α at the limbus, and subsequent limbal stem cell (LSC) damage. In this study, we investigate the protective role of TNF-α suppression in LSC survival. Corneal alkali injuries were performed using NaOH as previously described by our group. Anterior chamber pH elevation in the absence of corneal alkali exposure was achieved by cannulation. A CX3CR1 +/EGFP ::CCR2 +/RFP bone marrow chimera was used to study the role of innate immune cells in LSC damage, which was assessed by TUNEL assay, ABCB5, cytokeratin 12 and 13 staining, flow cytometry, in situ hybridization, and qPCR. Corneal neovascularization and conjunctivalization were evaluated by light microscopy. Intraperitoneal injection of 6.25 mg/kg infliximab was administered after irrigation. A TNFR1/2 knockout mouse was used to confirm the findings by a second method. Systemic administration of 6.25 mg/kg infliximab suppressed uveal inflammation after anterior chamber pH elevation or corneal alkali injury and led to reduction of TNF-α secreting CCR2 + and CX3CR1 + monocytes in the basal limbal tissue. In turn, this led to LSC survival ( P < 0.01) and allowed reestablishment of K12 + epithelium ( P < 0.05) on the injured cornea. Moreover, it led to less corneal neovascularization, conjunctivalization, and scarring, as compared with untreated animals. The protective effect of TNF-α suppression was confirmed in TNFR1/2 knockout mice. Prompt systemic administration of TNF-α inhibitor prevents LSC deficiency and facilitates corneal reepithelialization after alkali burn. TNF-α suppression may benefit the outcomes of other ocular injuries that cause LSC deficiency.
2023-06-13 | The Reliability of PCL/Anti-VEGF Electrospun Scaffolds to Support Limbal Stem Cells for Corneal Repair
Since only few reported studies propose anti-vascular endothelial growth factor (anti-VEGF) delivery through electrospun scaffolds, this study greatly contributes to the potential prevention of patient's vision loss, as it explores electrospun polycaprolactone (PCL) coated with anti-VEGF for the blockage of abnormal cornea vascularization. In terms of physicochemical properties, the biological component increased the PCL scaffold fiber diameter (by ~24%) and pore area (by ~82%), while ut slightly reduced its total porosity as the anti-VEGF solution filled the voids of the microfibrous structure. The addition of the anti-VEGF increased the scaffold stiffness almost three-fold at both strains of 5 and 10%, as well as its biodegradation rate (~36% after 60 days) with a sustained release profile after Day 4 of phosphate buffered saline incubation. In terms of scaffold application function, the PCL/Anti-VEGF scaffold proved to be more favorable for the adhesion of cultured limbal stem cells (LSCs); this was confirmed by the SEM images, where the cells showed flat and elongated conformations. Further support of the LSC growth and proliferation was confirmed by the identified p63 and CK3 markers after cell staining. These results demonstrate the advantageous effect of the surface-adsorbed anti-VEGF to stop vision loss and help damaged corneal tissue repair.
2023-05-08 | Refractory Keratolimbal Allograft Rejection in Autoimmune Polyglandular Syndrome-Associated Keratopathy Treated With Intravenous Immunoglobulin.
The aim of this study was to describe the use of intravenous immunoglobulin (IVIG) in the management of a 20-year-old woman with autoimmune polyglandular syndrome-associated keratopathy who developed acute transplant rejection after keratolimbal allograft (KLAL) surgery. Nine weeks after KLAL surgery, a 20-year-old woman with autoimmune polyglandular syndrome-related limbal stem cell deficiency presented with graft injection, hemorrhage, and an epithelial rejection line. This was concerning for acute rejection in the setting of triple-agent systemic immunosuppression (albeit nonadherence at times). There was initial reversal of the rejection process with a sub-Tenon's injection of triamcinolone, frequent topical corticosteroids, increase in oral prednisone, and optimization of systemic immunosuppression medications; however, recurrence of the epithelial rejection line and symptoms were noted whenever the prednisone dose was tapered. This was accompanied by ocular surface decompensation (late staining, neovascularization, and persistent epithelial defects). She was found to have weakly positive HLA Class 1 antibodies. The patient was treated with a pulsed corticosteroid infusion and 2 monthly IVIG infusions. This led to resolution of the acute rejection. However, there was a subsequent rejection episode 4 months later after tapering the prednisone. Monthly IVIG for 6 more months led to final resolution with successful prednisone tapering and no further rejection. Treatment with prolonged IVIG showed better improvement in a case of acute rejection refractory to traditional treatments, especially in the setting of HLA antibodies. The case demonstrates that close follow-up with a corneal specialist and collaboration with a transplant specialist is important to monitor for postoperative KLAL rejection.
2023-01-17 | Outcomes of keratolimbal allograft from ABO compatible donors for severe bilateral limbal stem cell deficiency.
To report outcomes of keratolimbal allograft (KLAL) compatible for both human leukocyte (HLA) and/or blood type using oral prednisone, mycophenolate, and tacrolimus, with basiliximab if panel reactive antibodies (PRA) are present. Intravenous immunoglobulin (IVIG) was used post-operatively if donor-specific anti-HLA antibodies (DSA) were present. Retrospective interventional series of consecutive patients with KLAL for limbal stem cell deficiency (LSCD) from HLA and/or blood type compatible deceased donors with a minimum follow-up time of 12 months. Main outcome measures were ocular surface stability, visual acuity and systemic immunosuppression (SI) adverse events. Eight eyes of eight patients with mean age of 48.6 ± 10.1 years (range 34-65 years) were included. Mean follow-up time was 37.3 ± 22.7 months (range 12-71 months) following KLAL; four (50%) had combined LR-CLAL surgery. The etiologies of LSCD were Stevens-Johnson Syndrome (n = 4/8), aniridia (n = 2/8), chemical injury (n = 1/8) and atopic eye disease (n = 1/8). All patients had PRA present and received basiliximab infusions. 5/8 patients received IVIG based on DSA identified pre-operatively. At last follow-up, 7 eyes (87.5%) had a stable ocular surface; 1 eye (12.5%) developed failure and had keratoprosthesis implantation. There was a significant improvement in visual acuity from 1.65 ± 0.48 to 0.68 ± 0.34 logMAR (p = 0.01). SI was tolerated well with minimal adverse events. Preliminary outcomes of KLAL with ABO compatible tissue using the Cincinnati protocol, preoperative basiliximab (when PRA present) and post-operative IVIG (when DSA present) are encouraging. This protocol may allow for utilization of deceased donor tissue with results approximating those of living donor tissue transplanted for severe bilateral LSCD.
other
2026-02-11 | Selective Disruption of Mutant TP63 Alleles Restores Corneal Epithelial proliferation in EEC Syndrome
Abstract Ectrodactyly–Ectodermal Dysplasia–Cleft Lip/Palate (EEC) syndrome is a rare disorder caused by dominant-negative mutations in the TP63 gene, frequently leading to limbal stem cell deficiency (LSCD) and progressive corneal degeneration. Current therapeutic strategies are limited, primarily due to impaired epithelial renewal and poor proliferative capacity of patient-derived cells. We have recently shown that decreasing the expression of the mutated allele by means of siRNA-mediated silencing can restore epithelial cell proliferation. However, the clinical utility of this approach is hindered by the presence of different TP63 mutations causing EEC syndrome, and the need for continuous siRNA administration to achieve sustained gene silencing. To address these challenges, we employed a CRISPR/Cas9-based genome editing strategy to disrupt mutant TP63 alleles in human induced pluripotent stem cells (hiPSCs) derived from EEC patients carrying R279H and R304Q mutations. Targeted editing of exon 6 induced frameshift mutations that activated nonsense-mediated mRNA decay, leading to a significant reduction in mutant transcript levels. Edited hiPSC-derived corneal epithelial cells exhibited improved cell proliferation compared to unedited isogenic controls. These findings demonstrate the feasibility and therapeutic potential of allele-specific genome editing to correct TP63-associated epithelial defects in EEC syndrome paving the way toward future regenerative therapies for TP63-related corneal diseases.
2024-09-24 | Limbal Stem Cell Deficiency After Treatment of Ocular Surface Squamous Neoplasia.
To investigate limbal stem cell deficiency (LSCD) in patients surgically treated for ocular surface squamous neoplasia (OSSN). This retrospective case-control study investigated clinical and histological data from patients with OSSN surgically treated in a referral center. The study included 98 patients (58 male, 40 female) with a mean age of 61.1 (23-86) years. Less than 3 clock hours were involved by OSSN in 48 eyes (49.0%), 3-6 clock hours in 32 eyes (32.7%), 6-9 clock hours in 12 eyes (12.2%), and more than 9 clock hours in 6 eyes (6.1%). Limbal stem cell deficiency was identified in 36 patients (36.7%) after surgery. The severity of LSCD was mild in 17 eyes, moderate in 11, and severe in 8. The prevalence of LSCD increased significantly in groups with 6 clock hours or more of OSSN involvement ( p < 0.001). The affected limbal side (superior, inferior, nasal, or temporal) had no significant association with the prevalence of LSCD ( p = 0.869). Patients with recurrent OSSN had a higher LSCD prevalence ( p = 0.003). The higher the tumor stage, the more likely it was to develop LSCD ( p < 0.001). Patients with corneal involvement were also more likely to develop LSCD ( p = 0.021). The prevalence of LSCD was raised with increasing histopathological grade ( p = 0.019). Furthermore, solely the number of clock hours affected by OSSN was an independent risk factor in multivariate analyses ( p < 0.001). The size and severity of OSSN and the presence of recurrent OSSN are associated with an increased likelihood of developing LSCD. Furthermore, the extent of the limbal area involved by the OSSN is identified as an independent risk factor of the development of LSCD.
2024-04-11 | Sox9 marks limbal stem cells and is required for asymmetric cell fate switch in the corneal epithelium
Adult tissues with high cellular turnover require a balance between stem cell renewal and differentiation, yet the mechanisms underlying this equilibrium are unclear. The cornea exhibits a polarized lateral flow of progenitors from the peripheral stem cell niche to the center; attributed to differences in cellular fate. To identify genes that are critical for regulating the asymmetric fates of limbal stem cells and their transient amplified progeny in the central cornea, we utilized an in vivo cell cycle reporter to isolate proliferating basal cells across the anterior ocular surface epithelium and performed single-cell transcriptional analysis. This strategy greatly increased the resolution and revealed distinct basal cell identities with unique expression profiles of structural genes and transcription factors. We focused on Sox9; a transcription factor implicated in stem cell regulation across various organs. Sox9 was found to be differentially expressed between limbal stem cells and their progeny in the central corneal. Lineage tracing analysis confirmed that Sox9 marks long-lived limbal stem cells and conditional deletion led to abnormal differentiation and squamous metaplasia in the central cornea. These data suggest a requirement for Sox9 for the switch to asymmetric fate and commitment toward differentiation, as transient cells exit the limbal niche. By inhibiting terminal differentiation of corneal progenitors and forcing them into perpetual symmetric divisions, we replicated the Sox9 loss-of-function phenotype. Our findings reveal an essential role for Sox9 for the spatial regulation of asymmetric fate in the corneal epithelium that is required to sustain tissue homeostasis.
2024-03-01 | Different Types of Therapies in Corneal Regeneration
The ocular surface is the outermost part of the visual system can experience physical or chemical damage from external or internal factors such as thermal harm, infectious pathogens, and burns, Steven Johnson Syndrome or, other autoimmune diseases.Limbal cells possess stem cell qualities and regenerative capabilities due to their capacity for differentiation.The regeneration of corneal wounds involves a multifaceted process encompassing cell death, proliferation, migration, differentiation, and remodeling of the extracellular matrix.Among various therapies for corneal regeneration, stem cell therapy stands out as the most promising due to its rapid recovery from infections.Although still in its early stages, interventions for treating corneal abnormalities are underway.These interventions involve the use of both viral and non-viral vectors to introduce genes into the cornea, employing in vivo, ex vivo, and in vitro methods.This review primarily focuses on the latest advancements utilizing biological modulators like gene therapy, signaling inhibitors, microRNA, and Nano formulations.Additionally, the paper concentrates on the latest therapies utilizing stem cells and advancements in the ocular drug delivery system, aiming to enhance potential therapies for the future treatment of ocular diseases.
2023-08-28 | FoxC1 activates limbal epithelial stem cells following corneal epithelial debridement.
Limbal epithelial stem cells are not only critical for corneal epithelial homeostasis but also have the capacity to change from a relatively quiescent mitotic phenotype to a rapidly proliferating cell in response to population depletion following corneal epithelial wounding. Pax6+/- mice display many abnormalities including corneal vascularization and these aberrations are consistent with a limbal stem cell deficiency (LSCD) phenotype. FoxC1 has an inhibitory effect on corneal avascularity and a positive role in stem cell maintenance in many tissues. However, the role of FoxC1 in limbal epithelial stem cells remains unknown. To unravel FoxC1's role(s) in limbal epithelial stem cell homeostasis, we utilized an adeno-associated virus (AAV) vector to topically deliver human FOXC1 proteins into Pax6 +/- mouse limbal epithelium. Under unperturbed conditions, overexpression of FOXC1 in the limbal epithelium had little significant change in differentiation (PAI-2, Krt12) and proliferation (BrdU, Ki67). Conversely, such overexpression resulted in a marked increase in the expression of putative limbal epithelial stem cell markers, N-cadherin and Lrig1. After corneal injuries in Pax6 +/- mice, FOXC1 overexpression enhanced the behavior of limbal epithelial stem cells from quiescence to a highly proliferative status. Overall, the treatment of AAV8-FOXC1 may be beneficial to the function of limbal epithelial stem cells in the context of a deficiency of Pax6 function.
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Drug Discovery Landscape
9 orphan drug designations for Limbal stem cell deficiency, including 1 approved therapy.
9 orphan drug designations for Limbal stem cell deficiency, including 1 approved therapy.
Drug | Therapy type | Orphan designation | Clinical trial status | Sponsor |
|---|---|---|---|---|
Spironolactone | small molecules | EMA | — | Dan Mejlachowicz |
allogeneic ABCB5-positive limbal stem cells | cell therapies | FDA | RHEACELL GmbH & Co. KG | |
Allogeneic ABCB5-positive limbal stem cells | cell therapies | EMA | Rheacell GmbH & Co. KG | |
ex vivo expanded autologous human corneal epithelial cells containing stem cells | cell therapies | FDA | — | Holostem S.r.l. |
Cultured allogeneic corneal limbal stem cells | cell therapies | EMA | — | NHS National Services Scotland Trading as Scottish National Blood Transfusion Service |
Ex-vivo expanded autologous human corneal epithelium containing stem cells | cell therapies | EMA | — | University of Newcastle upon Tyne |
Ex-vivo expanded autologous human corneal epithelium containing stem cells [Holoclar] | cell therapies | EMA | Approved | Holostem S.r.l. |
Bio-engineered oral mucosal tissue | cell therapies | FDA | — | TissueTech, Inc. |
Autologous or allogeneic limbal epithelial stem cells expanded ex vivo on human amniotic membrane | cell therapies | FDA | — | TissueTech, Inc. |
“Terminated” – programs with discontinued clinical trials, or with no updates reported for 5 years after completion or 12 years after the last trial started.
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