EIF1 coordinates transcriptomic and splicing networks associated with cell cycle dysregulation in diabetic retinopathy.

PURPOSE: EIF1, an RNA-binding protein implicated in multiple diseases, remains poorly characterized in diabetic retinopathy (DR). This study therefore investigated EIF1 expression and function in an in vitro model of DR pathogenesis. METHODS: Human retinal pigment epithelial cells (ARPE-19) were exposed to 50 mM glucose to model DR. EIF1 was knocked down using siRNA under hyperglycemic conditions, followed by transcriptome sequencing (RNA-seq) to profile differentially expressed genes (DEGs) and alternative splicing events (ASEs). Key findings from RNA-seq were validated by RT-qPCR. RESULTS: High-glucose treatment significantly suppressed cellular proliferation concurrent with EIF1 downregulation, suggesting that hyperglycemia-induced EIF1 depletion may impair retinal pigment epithelial cell functionality. Transcriptome sequencing revealed that EIF1 knockdown induced differential expression in 223 genes in total, comprising 35 upregulated and 188 downregulated genes. Notably, functional enrichment analysis revealed that downregulated genes are significantly enriched in cell cycle-related signaling pathways. Additionally, 1211 differential alternative splicing events were detected, primarily impacting cell cycle and p53 signaling pathways. Further analysis uncovered differentially expressed genes (e.g., BIRC5, MCM4, PLK1, RAD51, MELK, UBE2C, GINS2, and FANCA) and differentially spliced genes (e.g., COP1, TFE3) associated with the cell cycle after EIF1 knockdown. RT-qPCR validation confirmed the differential expression of key DEGs and the altered splicing patterns of COP1 and TFE3, consistent with RNA-seq predictions. These findings suggest that EIF1 may be associated with cell cycle dysregulation through the modulation of both gene expression and alternative splicing. CONCLUSIONS: This study suggests a potential role for EIF1 in DR pathogenesis in an in vitro model, identifying it as a candidate for further investigation. The data point to an association between EIF1 and the regulation of cell cycle-related genes at both the transcriptional and splicing levels.