Investigating the putative therapeutic effects of sulfophane in the human lens

Purpose: Cataract (a clouding of the lens) and PCO, a lens wound-healing response that occurs following cataract surgery, are important medical problems affecting millions worldwide. Reducing the incidence of these conditions would have a marked effect on the personal well being of millions of people. The isothiocyanate, SFN is known to have dose-dependent cytoprotective and cytotoxic properties. The present study had three aims. Firstly, to determine if the isothiocyanate, SFN could yield protection to lens cells against oxidative stress. Secondly, to identify the mechanisms by which SFN can elicit cytoprotection to lens cells against oxidative stress. The final aim was to establish the ability of SFN to initiate death of lens cells and prevent PCO formation. Methods: The human lens epithelial cell line FHL 124 was used in combination with whole porcine lens culture (to assess opacity) and human capsular bags (as a PCO model) were employed as the experimental systems. Whole lens cultures were monitored using brightfield and darkfield imaging; quantification was performed with ImageJ analysis software. Capsular bags were monitored using phase-contrast microscopy. The ApoToxGlo Triplex assay was used to assess FHL 124 cell survival, cytotoxicity and apoptosis. The MTS assay was used to assess cell populations. To determine levels of DNA strand breaks, the alkaline comet assay was performed and quantified. Lactate dehydrogenase levels in the medium (of FHL 124 cells and porcine lenses) were evaluated to reflect cell damage/death. To assess level of gene expression an Illumina whole genome HT-12 v4 beadchip microarray was employed. Real-time PCR was used to assess ER stress gene expression. Protein expression was validated by Western blot and immunocytochemistry (FHL 124 cells and capsular bags). Results: 30 M H2O2 exposure to FHL 124 cells caused a significant reduction in cell viability and increased cytotoxicity/apoptosis; these effects were significantly inhibited (~80%) by 24 hours pre-treatment with 1 M SFN. In addition, 1 M SFN significantly reduced H2O2-induced DNA strand breaks. When applied to cultured porcine lenses, SFN protected against H2O2-induced opacification. Illumina whole genome HT-12 v4 beadchip microarray data revealed 8 genes up-regulated following 24 hours exposure to 1 M or 2 M SFN. These included NQO1 and TXNRD1, which also demonstrated upregulation at the protein level. Nrf2 was found to actively translocate to the cell nucleus in response to a four hour exposure to 0.5, 1 and 2 M SFN. SFN was found to induce apoptosis and ER stress in FHL 124 cells at SFN concentrations 10 M and higher. Application of these concentrations of SFN to capsular bag cultures demonstrated a retardation of cell growth at 10 M and complete ablation with 100 M SFN Conclusions: The dietary component SFN, at low concentrations (≤5 M) demonstrates an ability to protect human lens cells against oxidative stress and thus could potentially delay the onset of cataract. It is likely that this protection is mediated by SFN induced Nrf2 signalling. Higher concentrations (≥10 M) of SFN are capable of inducing ER stress and cell death in human lens epithelial cells and thus provide a novel agent to be used in the prevention of PCO

Sulforaphane promotes ER stress, autophagy and cell death: implications for cataract surgery

Posterior capsule opacification (PCO) commonly develops following cataract surgery and is a wound-healing response that can ultimately lead to secondary visual loss. Improved management of this problem is required. The isothiocyanate, sulforaphane (SFN) is reported to exert cytoprotective and cytotoxic actions and the latter may be exploited to treat/prevent PCO. SFN concentrations of 10µM and above significantly impaired wound-healing in a human lens capsular bag model. A similar pattern of response was also seen with a human lens cell line, FHL124. SFN treatment promoted increased expression of ER stress genes, which also corresponded with protein expression. Evidence of autophagy was observed in response to SFN as determined by increased LC3-II levels and detection of autophagic vesicles. This response was disrupted by established autophagy inhibitors chloroquine and 3-MA. SFN was found to promote MAPK signaling and inhibition of ERK activation using U0126 prevented SFN induced LC3-II elevation and vesicle formation. SFN also significantly increased levels of reactive oxygen species. Taken together, our findings suggest that SFN is capable of reducing lens cell growth and viability and thus could serve as a putative therapeutic agent for PCO

Genetic mutations and molecular mechanisms of Fuchs endothelial corneal dystrophy

Abstract Background Fuchs endothelial corneal dystrophy is a hereditary disease and the most frequent cause of corneal transplantation in the worldwide. Its main clinical signs are an accelerated decrease in the number of endothelial cells, thickening of Descemet’s membrane and formation of guttae in the extracellular matrix. The cornea’s ability to maintain stromal dehydration is impaired, causing painful epithelial bullae and loss of vision at the point when the amount of corneal endothelial cells cannot be compensated. At present, apart from corneal transplantation, there is no other effective treatment that prevents blindness. Main text In this review, we first summarized the mutations of COL8A2, TCF4, TCF8, SLC4A11 and AGBL1 genes in Fuchs endothelial corneal dystrophy. The molecular mechanisms associated with Fuchs endothelial corneal dystrophy, such as endoplasmic reticulum stress and unfolded protein response pathway, oxidative stress, mitochondrial dysregulation pathway, apoptosis pathway, mitophagy, epithelial-mesenchymal transition pathway, RNA toxicity and repeat-associated non-ATG translation, and other pathogenesis, were then explored. Finally, we discussed several potential treatments related to the pathogenesis of Fuchs endothelial corneal dystrophy, which may be the focus of future research. Conclusions The pathogenesis of Fuchs endothelial corneal dystrophy is very complicated. Currently, corneal transplantation is an important method in the treatment of Fuchs endothelial corneal dystrophy. It is necessary to continuously explore the pathogenesis of Fuchs endothelial corneal dystrophy and establish the scientific foundations for the development of next-generation corneal therapeutics

Research Article Ocular Surface Epithelial Thickness Evaluation in Dry Eye Patients: Clinical Correlations

International audiencePurpose. To evaluate the relationship between corneal and conjunctival epithelium thickness and ocular surface clinical tests in dry eye disease (DED) patients. Patients and Methods. Fifty-four patients with DED and 32 control subjects were included. Each patient underwent an ocular surface evaluation using the ocular surface disease index (OSDI), tear film break-up time (TBUT), corneal and conjunctival staining, tear film lipid layer analysis, and Schirmer test. The central corneal (CET), limbal (LET), and bulbar conjunctival epithelium thickness (BET) were acquired using spectral-domain optical coherence tomography (SD-OCT). Results. Compared to control subjects, mean BET was significantly thicker and mean LET was significantly lower in the DED group. There was no significant difference in mean CET between the two groups. The mean LET was correlated with OSDI and TBUT. The inferior LET was correlated with OSDI, Schirmer I test, TBUT, Oxford score, and corneal sensitivity. Mean BET was correlated with OSDI and TBUT, but not with Schirmer I test and Oxford score. Conclusions. In dry eye patients, a thinner limbal epithelium and a thicker bulbar conjunctival epithelium were observed. These changes were correlated to the severity of dry eye symptoms and tear film alterations

Cost–utility analysis of commonly used anti-glaucoma interventions for mild-to-moderate primary open-angle glaucoma patients in rural and urban China

Objective An increasing number of studies have explored the clinical effects of antiglaucoma surgical procedures; however, economic evidence was scarce. We aimed to compare the cost-effectiveness between maximal medical treatment (MMT) and commonly used surgical procedures (trabeculectomy, Ahmed glaucoma valve implantation, gonioscopy-assisted transluminal trabeculotomy and ab interno canaloplasty).Design and setting A Markov model study.Participants A hypothetical cohort of 100 000 patients with mild-to-moderate primary open-angle glaucoma (POAG).Outcomes Data were obtained from public sources. The main outcomes were incremental cost–utility ratios (ICURs) using quality-adjusted life-years (QALYs). Sensitivity analyses were conducted to verify the robustness and sensitivity of base-case results.Main results Both cumulative costs and QALYs gained from surgical procedures (US$6045–US$13 598, 3.33–6.05 QALYs) were higher than those from MMT (US$3117–US$6458, 3.14–5.66 QALYs). Compared with MMT, all surgical procedures satisfied the cost-effectiveness threshold (lower than US$30 501 and US$41 568 per QALY gained in rural and urban settings, respectively). During the 5-year period, trabeculectomy produced the lowest ICUR (US$21 462 and US$15 242 per QALY gained in rural and urban settings, respectively). During the 10-year-follow-up, trabeculectomy still produced the lowest ICUR (US$13 379 per QALY gained) in urban setting; however, gonioscopy-assisted transluminal trabeculotomy (US$19 619 per QALY gained) and ab interno canaloplasty (US$18 003 per QALY gained) produced lower ICURs than trabeculectomy (US$19 675 per QALY gained) in rural areas. Base-case results were most sensitive to the utilities and costs of initial treatment and maintenance.Conclusions The long-term cost-effectiveness of commonly used surgical procedures could be better than the short-term cost-effectiveness for mild-to-moderate POAG patients in China. Health economic studies, supported by more rigorous structured real-world data, are needed to assess their everyday cost-effectiveness