Abstract Background Benzalkonium chloride (BAC), a commonly used preservative in ophthalmic formulations, elicits a pro-inflammatory cytokine response and cytotoxic effects in corneal epithelial cells, contributing to ocular surface injuries associated with dry eye disease (DED). Interleukin-6 (IL-6) trans-signaling is a well-established pro-inflammatory pathway that contributes to endothelial and epithelial barrier dysfunction. Thus, this study investigated whether targeted inhibition of IL-6 trans-signaling with sgp130Fc could attenuate BAC-induced cytotoxic injury in corneal epithelial cells. Methods Human telomerase-immortalized corneal epithelial (hTCEpi) cells were exposed to 0.001% BAC for 30 min in the presence or absence of 10 μg/mL sgp130Fc. Markers of inflammation, oxidative imbalance, endoplasmic reticulum (ER) stress, and epithelial barrier disruption were assessed using enzyme-linked immunosorbent assay, reverse transcriptase polymerase chain reaction, and western blot analyses. Reactive oxygen species (ROS), antioxidant capacity, and intracellular calcium flux were quantified using colorimetric, fluorescence-based, and luminescence-based assays. Epithelial barrier function was assessed using electric cell-substrate impedance sensing. Statistical analyses were performed using one-way analysis of variance followed by Tukey’s or Holm-Šídák multiple-comparison tests, with P < 0.05 considered statistically significant. Results BAC exposure activated IL-6 trans-signaling as indicated by an increased sIL-6R/sgp130 ratio, reduced mIL-6R levels, and unchanged gp130 levels. BAC also increased secreted IL6 levels, IL6RA expression, and downstream inflammatory mediators MCP1 and ICAM1 , all of which were attenuated by sgp130Fc. BAC-induced oxidative imbalance was characterized by increased ROS and hydrogen peroxide production, reduced antioxidant enzymes, and diminished total antioxidant capacity, whereas sgp130Fc mitigated these effects. In addition, BAC increased intracellular calcium levels and ER stress markers, including HSP72 , BiP, PERK, and Ero1α, and impaired epithelial barrier function as observed by reduced trans-epithelial electrical resistance and decreased β-catenin, occludin, and claudin-1 levels. sgp130Fc mitigated increases in intracellular calcium, partially alleviated ER stress responses, and preserved epithelial barrier integrity and junctional protein levels. Conclusions These findings indicate that IL-6 trans-signaling contributes to BAC-induced corneal epithelial injury, suggesting that targeting this pathway may have therapeutic potential for DED and related ocular surface inflammatory disorders.
Abstract Background We investigated the role of disulfidptosis, a recently identified form of cell death, in the pathogenesis of proliferative diabetic retinopathy (PDR) and explore the function of the cystine/glutamate antiporter, SLC7A11, as a key mediator and potential therapeutic target. Methods Bioinformatic analysis was used to screen disulfidptosis-related genes from public RNA sequencing datasets, which were subsequently validated in PDR fibrovascular membranes (FVMs) and vitreous humor via immunofluorescence and western blotting analysis. Human retinal microvascular endothelial cells (HRMECs) were cultured in normal or high-glucose media, and SLC7A11 expression modulated using small interfering RNA or lentiviral overexpression. Angiogenesis was assessed via proliferation, migration, and tube formation assays. Disulfidptosis was induced via acute glucose deprivation in high-glucose-adapted HRMECs and biochemically evaluated. A streptozotocin-induced diabetic mouse model was utilized to assess SLC7A11 expression in vivo, and therapeutic efficacy was tested through weekly intravitreal lavage with glucose-free versus glucose-replete solutions. Results Disulfidptosis-related genes, particularly SLC7A11 , were significantly upregulated in PDR FVMs, predominantly localizing to the vascular endothelium. In vitro, high-glucose conditions induced SLC7A11 and vascular endothelial growth factor A expression in HRMECs, thereby promoting proliferation, migration, and tube formation. SLC7A11 knockdown abrogated these pro-angiogenic effects, whereas overexpression exacerbated them. Critically, high-glucose-adapted cells developed a profound dependency on glucose; subsequent acute glucose deprivation triggered rapid cell death, exhibiting classic disulfidptosis features (F-actin collapse), a process that could not be rescued by ferroptosis inhibitors. In the diabetic mouse model, SLC7A11 expression was similarly upregulated in the pathological retinal vasculature. Therapeutic vitreous lavage with a glucose-free solution significantly attenuated the progression of these pathological neovessels. Conclusions Our results revealed a novel SLC7A11 -mediated metabolic vulnerability in PDR. We demonstrated that exploiting this glucose dependency via localized deprivation induces disulfidptosis-like features in neovascular cells, representing a new therapeutic strategy for PDR.
Abstract Background To evaluate the associations of the triglyceride-glucose (TyG) index and related adiposity-integrated indices with incident glaucoma and explore potential causal evidence using Mendelian randomization (MR). Methods This prospective cohort study included 396,213 participants without glaucoma of European ancestry from the UK. The TyG index and four related indices, including TyG-body mass index (TyG-BMI), TyG-waist circumference (TyG-WC), TyG-waist-to-height ratio (TyG-WHtR), and TyG-waist-to-hip ratio (TyG-WHR), were assessed. Multivariate Cox models and restricted cubic splines were used to examine the association with incident glaucoma. Associations between the corneal-compensated intraocular pressure (IOPcc) and retinal structures were assessed using regression analyses. The predictive performance was evaluated using extreme gradient boosting (XGBoost). Two-sample MR was conducted to assess the genetic association between the TyG index and glaucoma. Results During a mean follow-up of 8.06 years, 6957 cases of incident glaucoma occurred. In fully adjusted models, higher TyG and related indices were associated with increased glaucoma risk, including TyG (hazard ratio [HR] = 1.05, 95% confidence interval [CI]: 1.02–1.08), TyG-BMI (HR = 1.20, 95% CI: 1.14–1.27), TyG-WC (HR = 1.30, 95% CI: 1.23–1.37), TyG-WHtR (HR = 1.26, 95% CI: 1.20–1.31), and TyG-WHR (HR = 1.16, 95% CI: 1.12–1.21). The TyG showed a significant non-linear U-shaped association with incident glaucoma. TyG-related indices were positively associated with IOPcc, although the effect sizes were small and inversely associated with several measurements of retinal layer thickness. The XGBoost model showed good discrimination, with TyG-WHtR contributing the strongest among the TyG-related indices (C-index = 0.851, area under the curve = 0.823). MR provided suggestive evidence for an association between genetically predicted TyG and glaucoma risk (odds ratio = 1.27, 95% CI: 1.00–1.62, P = 0.046), although sensitivity estimates were not statistically significant. Conclusions TyG-related indices, particularly adiposity-integrated measures, were associated with a higher glaucoma risk. Systemic glucose-lipid metabolic dysfunction and central adiposity may contribute to glaucoma susceptibility. Thus, TyG-related indices may serve as low-cost adjunct indicators for glaucoma risk stratification and external validation.
Abstract Background Primary open-angle glaucoma (POAG) is the most prevalent glaucoma subtype globally and has disproportionately high rates in Africa. While smoking and alcohol consumption are established risk factors for several ocular conditions, their associations with POAG remain unclear. This study examined substance use patterns among individuals with and without POAG in sub-Saharan Africa. Methods This cross-sectional study included 9,418 participants aged ≥ 40 years (5,189 POAG cases and 4,229 controls) from the Eyes of Africa: Genetics of Blindness study conducted across Nigeria, Ghana, and Malawi between 2017 and 2023. Comprehensive ocular examinations were performed, and POAG was diagnosed according to the International Society of Geographical and Epidemiologic Ophthalmology criteria. Sociodemographic data and detailed information on the use of substances including alcohol, tobacco, pharmaceutical substances, and illicit drugs, were collected through structured interviews. Chi-squared tests were used to examine the associations between variables, and multivariable logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for substance use and POAG status. Results Alcohol consumption and tobacco smoking were strongly and independently associated with POAG ( P < 0.001). Former (OR = 1.49; 95% CI: 1.33–1.66; P < 0.001) and current drinkers (OR = 1.15; 95% CI: 1.00–1.31; P = 0.04) had higher odds than never-drinkers. Lifetime heavy episodic drinking (> 2 drinks per occasion) was associated with 40% higher odds of POAG (95% CI: 1.20–1.65; P < 0.001) than having ≤ 2 drinks. Tobacco use was also independently associated with POAG among both former (OR = 1.38; 95% CI: 1.13–1.68; P = 0.002) and current smokers (OR = 1.46; 95% CI: 1.12–1.91; P = 0.005). In addition, older age, male sex, higher educational level, and unemployment (all P < 0.001) were independently associated with POAG. Conclusion Cigarette smoking and alcohol use are significantly associated with increased risk of POAG in this African population, representing potentially modifiable risk factors. Confirmatory longitudinal studies are needed to establish causality. If validated, public health strategies for POAG prevention in Africa should incorporate substance use reduction as a key component of primary prevention.
Histological examination of surgically excised internal limiting membrane (ILM) specimens may provide insights into retinal tissue changes, but their relationship to retinal imaging findings remains unclear. The aim of this study was to correlate retinal imaging findings with histological evidence of retinal tissue components in surgically excised ILM specimens from eyes with idiopathic epiretinal membrane (iERM) or full-thickness macular hole (FTMH). This retrospective clinicopathological study included 42 eyes that underwent pars plana vitrectomy with membrane peeling at the Department of Ophthalmology, University Hospital Ulm, Germany, between April 2024 and May 2025: 22 eyes with iERM and 20 with FTMH. Surgically excised tissue from all eyes was examined by transmission electron microscopy (TEM), and clinical data and retinal imaging findings obtained by optical coherence tomography (OCT) were evaluated. TEM confirmed the ILM in all included eyes. Intact retinal glial cells with ultrastructural features consistent with Müller cells were observed in localized areas of ILM thinning in 3 eyes with iERM but in no eyes with FTMH. Retinal cell fragments were detected in 21 eyes with iERM and 18 eyes with FTMH. Among eyes with iERM, those containing retinal glial cells had a significantly greater mean central macular thickness (CMT, 619 ± 57 µm) than those without retinal glial cells (P = 0.008); all 3 eyes had Stage 3 epiretinal membrane (ERM), ectopic inner foveal layers (EIFL), and central bouquet abnormalities (CBA). OCT findings did not differ according to retinal cell fragment size. Retinal glial cells adherent to the ILM were identified only in eyes with iERM and were associated with higher-stage ERM, often in areas of ILM thinning. By contrast, retinal cell fragments occurred in both iERM and FTMH. These findings suggest disease-specific differences at the vitreoretinal interface, with stronger and more complex retinal–ILM interactions in iERM that may influence ILM peeling.
