Lens epithelium cell ferroptosis mediated by m 6 A-lncRNA and GPX4 expression in lens tissue of age-related cataract.

BACKGROUND: In the present study, we explored the role of N6 -methyladenosine (m6 A) modification of long non-coding RNAs (lncRNAs) and its association with ferroptosis in lens epithelium cells (LECs) of age-related cataract (ARC).

METHODS: Through m6 A RNA immunoprecipitation sequencing (m6 A-RIP-seq) and RNA sequencing (RNA-seq), we identified m6 A mediated and differentially expressed lncRNAs (dme-lncRNAs) in ARC patients. Based on bioinformatics analysis, we selected critical dme-lncRNAs and pathways associated with ARC formation to reveal their potential molecular mechanisms. The downregulation of glutathione peroxidase 4 (GPX4), a key component of ferroptosis, was confirmed by real-time RT-PCR (RT-qPCR) and Western blotting in age-related cortical cataract (ARCC) samples. Transmission electron microscopy was used to assess the change in mitochondrial in LECs.

RESULTS: The analysis revealed a total of 11,193 m6 A peaks within lncRNAs, among which 7043 were enriched and 4150 were depleted. Among those, lncRNA ENST00000586817(upstream of the GPX4 gene) was not only significantly upregulated in the LECs of ARCC but also potentially augmented the expression of GPX4 through a cis mechanism. The expression of m6 A-modified lncRNA (ENST00000586817) was correlated with that of GPX4 and was downregulated in ARC patients. The TEM results indicated significant mitochondrial changes in ARCC samples. GPX4 downregulation enhanced LEC ferroptosis and decreased viability via RSL3 in SRA01/04 cells.

CONCLUSIONS: Our results provide insight into the potential function of m6 A-modified lncRNAs. M6 A-modified lncRNA ENST00000586817 might regulate the expression of GPX4 by a cis mechanism and be implicated in ferroptosis in ARCs.