Long non-coding RNA KCNQ1OT1 promotes hydrogen peroxide-induced lens epithelial cell apoptosis and oxidative stress by regulating miR-223-3p/BCL2L2 axis

Many long non-coding RNAs (lncRNAs) can exert crucial roles in the pathogenesis of cataract, including lncRNA KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1). We aimed to further elucidate the biological role and regulatory molecular mechanism of KCNQ1OT1 in cataract. The expression of KCNQ1OT1 and miR-223-3p and BCL2 like 2 (BCL2L2) was examined by qRT-PCR. Cataract cell model was constructed by treatment with hydrogen peroxide (H2O2) in lens epithelial cells (SRA01/04). SRA01/04 cell viability and cell apoptosis were tested using CCK-8 assay and flow cytometry, respectively. Western blot (WB) was performed to measure the levels of apoptosis-related proteins and BCL2L2 protein. The oxidative stress factors were analyzed by corresponding kits. The interaction between miR-223-3p and KCNQ1OT1 or BCL2L2 was validated by dual-luciferase reporter and RNA Immunoprecipitation (RIP) assays. We found that KCNQ1OT1 was upregulated in cataract anterior lens capsule samples and H2O2-induced SRA01/04 cells. Knockdown of KCNQ1OT1 suppressed H2O2induced SRA01/04 cell apoptosis and oxidative stress. KCNQ1OT1 acted as a sponge of miR-223-3p. Inhibition of miR-223-3p could abate the function of KCNQ1OT1 silence in H2O2-treated SRA01/04 cells. Additionally, BCL2L2 was a direct target of miR-223-3p, and miR-223-3p weakened H2O2-induced SRA01/04 cell apoptosis and oxidative stress by targeting BCL2L2. Collectively, the data suggest a role for the KCNQ1OT1/miR-223-3p/ BCL2L2 axis in cataract formation but the data was generated using an epithelial cell line.