Indian Journal of Ophthalmology最新文献

Purpose: This study was designed to investigate the primary targets and possible mechanisms of ranitidine (Ra) against diabetic retinopathy (DR).

Methods: Single-cell sequencing technology and the SPIED3 platform were employed to characterize key genes in retinal Müller cells (RMCs) of diabetic mice and identify potential small-molecule compounds separately. The effects of small-molecule compounds on the cell viability and proliferative capacity of mouse retinal Müller cells (rMC-1) cultured in high-glucose (HG) were evaluated using the cell counting kit-8 (cck-8) and 5-ethyl-2-deoxyuridine (Edu) assay. Glutathione (GSH), malondialdehyde (MDA), reactive oxygen species (ROS), and Fe2+ were identified as indicators of ferroptosis. Then, network pharmacology was used to predict specific targets for Ra. Western blotting was used to identify ferroptosis-related proteins, including glutathione peroxidase 4 (GPX4), cystine/glutamate transporter (xCT), serine/threonine-protein kinase AKT1, and glycogen synthase kinase-3β (GSK3β).

Results: The predicted results suggested that the potential mechanism of RMCs damage in diabetic mice is associated with ferroptosis. The cck-8 results indicated Ra played a regulatory role in HG-induced rMC-1 by enhancing cell viability. Besides, Edu results showed that Ra promoted the proliferation of rMC-1 cells. Network pharmacological analyses predicted a potential mechanism of Ra effect in HG-induced rMC-1, mainly associated with the AKT1 and GSK3β genes. Phenotypically, Ra elevated intracellular GSH levels, while reducing MDA, Fe²⁺, and ROS concentrations. Mechanistically, Ra increased xCT and GPX4 expression through the promotion of AKT1/GSK3β phosphorylation, thereby alleviating ferroptosis in HG-induced rMC-1 cells.

Conclusions: The study highlighted that the mechanism of DR is closely associated with ferroptosis and demonstrated that Ra inhibits HG-induced ferroptosis of rMC-1 cells by regulating the AKT1/GSK3β signaling pathway, thereby providing a theoretical basis for using Ra in managing DR.

Purpose: Fusion transcripts have been reported as biomarkers for several diseases; however, a fusion gene has not been reported in ophthalmic disease. To the best of our knowledge, the discovery of fusion transcript in Behcet's disease (BD), a noninfectious uveitis, is reported for the first time. We generated complete transcript data for BD subtape and discovered fusion transcripts specific to BD patients.

Methods: We sequenced total RNA from peripheral blood mononuclear cells isolated from clinically characterized BD patients and controls and generated BAM files, which served as input data for predicting fusion transcripts. We used Arriba, a computational tool for the detection of fusion transcripts. Arriba is fast and accurate for the identification of gene fusions from RNA sequencing data. It is specifically designed for high-throughput RNA-seq data, leveraging STAR-aligned chimeric BAM files to detect fusion events with high sensitivity.

Results: The Arriba tool identified a set of fusion transcripts specific to BD patients. One of the fusion transcripts was characterized and validated, which represents the read-through fusion with a product size of 421 bp consisting of a part of exon 2 of NFATC2 (112bp) and a part of exon 28 of ATP9A (309 bp); these are adjacent genes in chromosome 20.

Conclusion: This paper reports the discovery of fusion transcript in uveitis-BD subtype and is also the first report for any ophthalmic disease. Such fusion transcript is absent in controls and other subtypes of uveitis. It may be a possible biomarker for the noninfectious BD patients.

Purpose: Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss in the elderly. This study investigated the association of single-nucleotide polymorphisms (SNPs) in ARMS2, HTRA1, and CFH with AMD and its clinical phenotypes and systemic cytokine profiles in a North Indian population.

Method: A total of 113 AMD patients and 99 controls were genotyped using TaqMan assays. All patients underwent detailed ophthalmic evaluations, including optical coherence tomography (OCT), fundus photography, and angiography-based imaging. Serum cytokine levels were quantified using bead-based multiplex immunoassay and analyzed via flow cytometry. Statistical analyses were performed using SPSS v23.0, employing t-tests, ANOVA, and Mann-Whitney U tests.

Results: Significant associations were observed between AMD and control for risk alleles in ARMS2 (36.3% vs 10.1%, P = 0.001), HTRA1 (37.2% vs 33.3%, P = 0.003), and CFH (27.4% vs 13.1%, P = 0.001). Genotype-phenotype correlations revealed that heterozygous and homozygous risk genotypes were significantly associated with hallmark AMD features such as pigment epithelial detachment (PED), choroidal neovascular membrane (CNVM), large drusen, and retinal pigment epithelium (RPE) atrophy. Cytokine profiling showed significantly reduced levels of erythropoietin (EPO) in AMD patients and granulocyte colony-stimulating factor (G-CSF) in controls (P = 0.044 and P = 0.023).

Conclusion: This study establishes novel genotype-phenotype correlations for ARMS2, HTRA1, and CFH SNPs in a North Indian cohort, linking heterozygous/homozygous risk alleles to distinct AMD clinical features. Reduced EPO and G-CSF levels suggest impaired neuroprotective/anti-inflammatory mechanisms, revealing dual pathways in AMD pathogenesis. By integrating these findings with global data, future efforts can deepen our understanding of AMD's complex etiology and improve patient outcomes worldwide.