miR-211 promotes lens epithelial cells apoptosis by targeting silent mating-type information regulation 2 homolog 1 in age-related cataracts.

Aim: To detect the expression of miR-211 in age-related cataract tissue, explore the effects of miR-211 on lens epithelial cell proliferation and apoptosis, and identify its target gene.

Methods: This study used real-time quantitative polymerase chain reaction (RT-qPCR) to measure the expression of miR-211 and its predicted target gene [silent mating-type information regulation 2 homolog 1 (SIRT1)] in 46 anterior lens capsules collected from age-related cataract patients. Human lens epithelial cell line (SRA01/04) cells were transfected with either miR-211 mimics, mimic controls, miR-211 inhibitors or inhibitor controls, 72h after transfection, miRNA and protein expression of SIRT1 were measured using RT-qPCR and Western blotting; then cells were exposed to 200 µmol/L HO for 1h, whereupon cell viability was measured by MTS assay, caspase-3 assay was performed. Dual luciferase reporter assay was performed to verify the relationship between miR-211 of SIRT1.

Results: Compared to the control group, expression of miR-211 was significantly increased (<0.001), the miRNA and protein expression of SIRT1 were significantly decreased (<0.001) in the anterior lens capsules of patients with age-related cataracts. Relative to the control group, SIRT1 miRNA and protein levels in the miR-211 mimic group were significantly reduced, cell proliferation activity significantly decreased, and caspase-3 activity was significantly increased (<0.001). In the miR-211 inhibitor group, SIRT1 miRNA and protein expression were significantly increased, cell proliferation activity significantly increased, and caspase-3 activity was significantly decreased (<0.001). A dual luciferase reporter assay confirmed that SIRT1 is a direct target of miR-211.

Conclusion: miR-211 is highly expressed in the anterior lens capsules of patients with age-related cataracts. By negatively regulating the expression of SIRT1, miR-211 promotes lens epithelial cell apoptosis and inhibits lens epithelial cell proliferation.