The m(5)C demethylase TET1 is identified as a key regulator of scleral remodeling in myopia.

BACKGROUND: The global prevalence of myopia has risen sharply, particularly among children and adolescents in urban and highly educated populations. RNA modifications have been recognized as important regulators in myopia progression. However, the role of m(5)C, a crucial RNA modification, remains largely unexplored in myopia progression. METHODS: Key RNA modification-related genes were first identified through weighted gene co-expression network analysis (WGCNA), based on expression profiles of m(6)A‑, m(1)A‑, m(5)C‑, and m(7)G‑associated genes from the mouse myopic sclera dataset PRJCA000717. Pathway enrichment analysis was performed via Gene Set Enrichment Analysis (GSEA), and immune infiltration characteristics were evaluated using CIBERSORT. Further experimental validation included RT-qPCR and Western blotting to confirm TET1 up-regulation in a hypoxia-induced model of human scleral fibroblasts (HSFs), and functional assessments via knockdown experiments. RESULTS: Utilizing WGCNA, we identified Tet1, an m(5)C demethylase, as a key gene associated with myopia. Its expression was significantly elevated in myopic scleral samples. We further confirmed the increased TET1 expression in hypoxia-induced HSFs. TET1 was found to be involved in pivotal biological processes and the scleral microenvironment. Immune cell infiltration analysis revealed a significant negative correlation between Tet1 and eosinophils. GSEA indicated that Tet1‑related pathways include the proteasome, HIF‑1 signaling, and TGF‑β signaling. Knockdown of TET1 reversed hypoxia‑induced increases in apoptosis, restored m(5)C modification levels, and promoted HSF proliferation. Additionally, TET1 down‑regulation elevated COL1A1 protein expression while reducing α‑SMA, a key marker of scleral remodeling. Data from the GeneCards database showed that Tet1 expression significantly correlated with several myopia‑related progression genes, including Col2a1 (p = 0.002) and Fbn1 (p < 0.001). CONCLUSION: Our study reveals substantial alterations in TET1 expression and m(5)C modification in myopic sclera, providing new insights that may inform the development of novel diagnostic and therapeutic approaches for myopia management.