Necrostatin-1 protects corneal epithelial cells by inhibiting the RIPK1/RIPK3/MLKL cascade in a benzalkonium chloride-induced model of necroptosis.

PURPOSE: Benzalkonium chloride (BAC) is commonly used as a preservative in ophthalmic medications, despite its potential to induce chemical injury. Extensive research has demonstrated that BAC can lead to adverse effects, including injuries to the ocular surface. Our study aimed to elucidate the underlying mechanism of necroptosis induced by BAC. METHODS: Human corneal epithelial (HCE) cells and mouse corneas were subjected to chemical injury, and the necrostatin-1 (Nec1) group was compared to the dimethylsulfoxide (DMSO) group. The extent of damage to HCE cells was assessed using CCK-8 and flow cytometry. Hematoxylin and eosin staining, as well as fluorescein sodium staining, were used to detect and characterize corneal injury. The activation of inflammatory cytokines and necroptosis-related proteins and genes was evaluated using Western blotting, immunofluorescence staining, and quantitative RT‒PCR. RESULTS: In our study, the induction of necroptosis by a hypertonic solution was not observed. However, necroptosis was observed in HCE cells exposed to NaOH and BAC, which activated the receptor-interacting protein kinase 1 (RIPK1) - receptor-interacting protein kinase 3 (RIPK3) - mixed lineage kinase domain-like protein (MLKL) signaling pathway. In mouse corneal tissues, BAC could induce necroptosis and inflammation. The administration of Nec1 mitigated the inflammatory response and ocular surface damage caused by BAC-induced necroptosis in our experimental models. Furthermore, our in vivo experiments revealed that the severity of necroptosis was greater in the 3-day group than in the 7-day group. CONCLUSIONS: Necroptosis plays a role in the pathological development of ocular surface injury caused by exposure to BAC. Furthermore, our study demonstrated that the administration of Nec1 could mitigate the pathological effects of necroptosis induced by BAC in clinical settings.

Characteristics of refractive development in children aged 4 months to 8 years in urban China: A retrospective screening analysis.

PURPOSE: To conduct a large retrospective study of screening refractive error in young children. METHODS: This retrospective study included children aged from 4 months to 8 years in Daxing District, Beijing, who underwent refractive examinations without cycloplegia. It included a cross-sectional assessment of refractive error screening for all children, and a longitudinal component for a subgroup with data available for two to five visits. RESULTS: A total of 14,987 children were included in the cross-sectional study. In the group <1 year of age, the percentage of children with a spherical equivalent (SE) >+2.00 D or with cylinder <-1.50 D was 15.25% and 33.24%, respectively. These were significantly higher than for the 1- to 4-year-old group (SE 8.1% higher, cylinder 13.2% higher) (χ2 = 53.57, p < 0.001; χ2 = 790.39, p < 0.001). Furthermore, 34.83% of children in the 0-year-old group had amblyopia risk factors (ARFs). In the 4-year-old group, boys had a significantly longer axial length (AL) than girls (differences in the right and left eyes were 0.53 and 0.56 mm, respectively; z = 5.48 p < 0.001, z = 5.80, p < 0.001). AL increased with age, while the AL difference between boys and girls remained stable at 4-8 years of age. The percentage of children aged 5-8 years with myopia in 2020-2021 was significantly higher than that in 2018-2019 (H = 12.44, p = 0.006). In the longitudinal study of 4406 children (up to 12-month follow-up), annual changes in SE were -0.27, -0.06, 0.19 and 0.13 D between 0 and 3 years, and -0.38, -0.58, -0.70 and -0.75 D between 5 and 8 years. CONCLUSIONS: Children's refractive error varied significantly from ages 4 months to 1 year, with a high proportion having ARFs. Children aged 5-8 years showed a trend towards myopia. The prevalence of myopia in the cross-sectional analysis in 2020-2021 was greater than in 2018-2019. Screening refraction changed minimally over a 12-month period for children aged 1-3 years, but became more myopic for children aged 5-8 years.

Mesenchymal Stem Cell-Derived Exosomes as Drug Carriers for Delivering miRNA-29b to Ameliorate Inflammation in Corneal Injury Via Activating Autophagy.

Purpose: Corneal injury (CI) resulting in corneal opacity remains a clinical challenge. Exosomes (Exos) derived from bone marrow mesenchymal stem cells (BMSCs) have been proven effective in repairing various tissue injuries and are also considered excellent drug carriers due to their biological properties. Recently, microRNA-29b (miR-29b) was found to play an important role in the autophagy regulation which correlates with cell inflammation and fibrosis. However, the effects of miR-29b and autophagy on CI remain unclear. To find better treatments for CI, we used Exos to carry miR-29b and investigated its effects in the treatment of CI. Methods: BMSCs were transfected with miR-29b-3p agomir/antagomir and negative controls (NCs) to obtain Exos-29b-ago, Exos-29b-anta, and Exos-NC. C57BL/6J mice that underwent CI surgeries were treated with Exos-29b-ago, Exos-29b-anta, Exos-NC, or PBS. The autophagy, inflammation, and fibrosis of the cornea were estimated by slit-lamp, hematoxylin and eosin (H&E) staining, immunofluorescence, RT‒qPCR, and Western blot. The effects of miR-29b-3p on autophagy and inflammation in immortalized human corneal epithelial cells (iHCECs) were also investigated. Results: Compared to PBS, Exos-29b-ago, Exos-29b-anta, and Exos-NC all could ameliorate corneal inflammation and fibrosis. However, Exos-29b-ago, which accumulated a large amount of miR-29b-3p, exerted excellent potency via autophagy activation by inhibiting the PI3K/AKT/mTOR pathway and further inhibited corneal inflammation via the mTOR/NF-κB/IL-1ß pathway. After Exos-29b-ago treatment, the expressions of collagen type III, α-smooth muscle actin, fibronectin, and vimentin were significantly decreased than in other groups. In addition, overexpression of miR-29b-3p prevented iHCECs from autophagy impairment and inflammatory injury. Conclusions: Exos from BMSCs carrying miR-29b-3p can significantly improve the therapeutic effect on CI via activating autophagy and further inhibiting corneal inflammation and fibrosis.

Bioinformatics analysis of signature genes related to cell death in keratoconus.

Keratoconus is corneal disease in which the progression of conical dilation of cornea leads to reduced visual acuity and even corneal perforation. However, the etiology mechanism of keratoconus is still unclear. This study aims to identify the signature genes related to cell death in keratoconus and examine the function of these genes. A dataset of keratoconus from the GEO database was analysed to identify the differentially expressed genes (DEGs). A total of 3558 DEGs were screened from GSE151631. The results of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that they mainly involved in response to hypoxia, cell-cell adhesion, and IL-17 signaling pathway. Then, the cell death-related genes datasets were intersected with the above 3558 DEGs to obtain 70 ferroptosis-related DEGs (FDEGs), 32 autophagy-related DEGs (ADEGs), six pyroptosis-related DEGs (PDEGs), four disulfidptosis-related DEGs (DDEGs), and one cuproptosis-related DEGs (CDEGs). After using Least absolute shrinkage and selection operator (LASSO), Random Forest analysis, and receiver operating characteristic (ROC) curve analysis, one ferroptosis-related gene (TNFAIP3) and five autophagy-related genes (CDKN1A, HSPA5, MAPK8IP1, PPP1R15A, and VEGFA) were screened out. The expressions of the above six genes were significantly decreased in keratoconus and the area under the curve (AUC) values of these genes was 0.944, 0.893, 0.797, 0.726, 0.882 and 0.779 respectively. GSEA analysis showed that the above six genes mainly play an important role in allograft rejection, asthma, and circadian rhythm etc. In conclusion, the results of this study suggested that focusing on these genes and autoimmune diseases will be a beneficial perspective for the keratoconus etiology research.

Assessment of dynamic corneal response parameters in Chinese patients of different ages with myopia and orthokeratology lenses using the Corvis ST.

OBJECTIVE: To investigate the effects of orthokeratology lenses (OK lenses) on corneal biomechanics in subjects of different ages. METHODS: Fifty subjects with mild to moderate myopia were categorized into three groups (Group I-III) based on their age. Corvis ST was used to collect dynamic corneal response parameters (DCRs) at different follow-up time points. Repeated measures analysis of variance combined with simple effect analysis was used to analyze the changes in DCRs in different groups during the follow-up period. Multiple linear regression analysis was used to analyze the correlations between axial length growth (ALG) at 6 months (ALG-6M) or 12 months (ALG-12M) and sex, baseline spherical equivalent refraction (SER), and DCRs. RESULTS: The DCRs changed in all three groups after wearing OK lenses. Most DCRs showed significant differences between baseline and 6 months after wearing OK lenses, while the differences between DCRs at 6 months and 12 months were not statistically significant. No significant differences in DCRs were observed among the three groups at the same follow-up time point. Additionally, at 6 months post-OK lens wear, ALG-6M was significantly correlated with velocity of the corneal apex at the first applanation (A1V-6M) (P = 0.002), Corvis biomechanical index (CBI-6M) (P = 0.004), the maximum amount of corneal movement (DAM-6M) (P = 0.010), deformation amplitude ratio of 2 mm (DAR2-6M) (P = 0.010), and stress-strain index (SSI-6M) (P = 0.038) in Group I. Furthermore, ALG-12M showed significant correlations with SSI-6M (P = 0.031), peak distance at the DAM (PD)-6M (P = 0.037), baseline Ambrósio Relational Thickness to the horizontal profile (P = 0.013) in Group I. CONCLUSIONS: The majority of DCRs displayed significant changes within the initial 6 months of OK lens wear. Minimal variation in DCRs was observed across different age groups at the same follow-up time point. Certain DCR parameters exhibited correlations with ALG, suggesting their potential in predicting ALG in myopic children undergoing OK lenses correction.