Apoptosis of human lens epithelial (HLE) cells is a process closely associated with cataract formation. The aim of the present study was to explore the effects of microRNA (miR)‑181a against hydrogen peroxide (H2O2)-induced apoptosis in HLE cells in vitro. The recombinant lentiviral plasmid pLKO. 1‑puro‑miR‑181a was constructed and used to transfect human HLE‑B3 cells with the short hairpin (sh)RNA to silence the expression of miR‑181a. The apoptotic rate of both HLE‑B3 cells in which miR‑181a expression was stably silenced and in untransfected HLE‑B3 cells was assessed in the presence of H2O2 using flow cytometry. The mRNA expression levels of the apoptosis‑related genes caspase-3 (CASP3) and B‑cell lymphoma‑2‑associated X protein (BAX), and of the potential target genes for miR‑181a, c‑MET, cyclooxygenase 2 (COX‑2) and snail family transcriptional repressor 2 (SNAI2) were measured using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). Malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) levels were assessed using ELISA. RT‑qPCR analysis revealed that miR‑181a expression was downregulated in HLE‑B3 cells following transfection with miR‑181a‑shRNA. Treatment with H2O2 significantly reduced the viability of HLE‑B3 cells, whereas miR‑181a knockdown was revealed to attenuate the effects on cell viability following H2O2 treatment. In addition, the downregulation of miR‑181a expression significantly decreased H2O2‑induced cell apoptosis, which was accompanied by a downregulation in CASP3 and BAX and COX‑2 expression. Furthermore, the levels of MDA were decreased, whereas the levels of SOD and CAT were increased following miR‑181a silencing. The present findings suggested that miR‑181a knockdown may protect HLE‑B3 cells against H2O2‑induced apoptosis in vitro. The molecular mechanisms involved in the protective effects of miR‑181a silencing may involve the suppression of CASP3, BAX and COX‑2 expression, and the inhibition of MDA generation.
Keywords: cataract; lentivirus-based RNA interference; cell apoptosis; human lens epithelial cells; miRNA-181a.