miR-211 inhibitor up-regulates the progression of age-related cataract by targeting Notch22-mediated expression of β-crystallin B2

Objective To investigate the role and its potential mechanism of microRNA-211(miR-211) and β-crystalin B2 in aging-related cataract. Methods CCK-8 and flow cytometry were used to detect the cell growth of HLEC-3 cell after treated with different concentrations of hydrogen peroxide or different expressions of miRNA-211.Bioinformatics method was used to predict the potential binding sites of miRNA-211 to Notch2.Westren blot and quantitative reverse transcription polymerase chain reaction(qRT-PCR) were used to detect the expression of Nocth2 protein and Mrna in HLEC-3 cells after treatment with miR-211.Luciferase reporter was used to confirm the direct target gene of miR-211.Western blot was used to detect the changes of beta-crystallin B2 protein after single or co-expression of miRNA-211+ Notch2 or low expression of Notch2. Results Hydrogen peroxide (H2O2) could significantly reduce the cell viability of HLCE-3 cells(t=3.67, P<0.05). Down-regulation of miRNA-211 can significantly inhibit the apoptosis of HLEC-B3 induced by H2O2(t=4.07, P<0.05). However, up-regulation of miR-211-211 can significantly increase the expression of oxidizing factors(t=4.21, P<0.05). Luciferase and Western blot studies showed that up-regulation of miRNA-211 targeted inhibition of Notch2 expression(t values were 4.02 and 3.90, both P values <0.05). Similarly, down-regulation of miR-211 could revised the expression of Notch2(t=4.04, P<0.05). In addition to Notch2, miR-211 inhibitor also enhanced β-crystallin B2 expression.Beta-crystallin B2 expression induced by miR-211 inhibitor could be significantly inhibited after Notch2 expression were silenced (t values were 4.20, 4.19 and 4.15 respectively, all P values <0.05). Conclusions These data demonstrated that miR-211 inhibitor increased β-crystallin B2 expression via up-regulating Notch2, which indicated that miR-211 inhibitor might be a promising candidate to prevent progression of age-related cataract. Key words: microRNA-211; Age-related cataract; Notch21; β-crystallin B2