Long non-coding RNA nuclear paraspeckle assembly transcript 1 protects human lens epithelial cells against H2O2 stimuli through the nuclear factor kappa b/p65 and p38/mitogen-activated protein kinase axis

Background Long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) plays a regulatory role in many biological processes; however, its role in cataracts has yet to be illuminated. This study aimed to investigate the protective role of NEAT1 in hydrogen peroxide (H2O2)-treated human lens epithelial cells (HLECs) and its underlying molecular mechanism. Methods HLECs (SRA01/04) were treated with 300 µM H2O2 to mimic cataract in vitro. Cell viability was detected by performing an MTT assay and EdU staining. Flow cytometry was carried out to detect apoptosis of HLECs. DNA damage was examined using γ-H2A histone family member X staining. and reactive oxygen species (ROS) production was measured using 2',7'dichlorofluorescin diacetate staining. The expression levels of lncRNA and proteins were detected with quantitative real-time polymerase chain reaction and western blot, respectively. Results The expression of NEAT1 was observed to be increased in H2O2-treated HLECs and age-related cataract (ARC) tissues. Knockdown NEAT1 strongly protected against H2O2-induced cell death and also regulated the expression of cleaved caspase-3, B-cell lymphoma 2, and Bcl-2-associated X protein. Further, knockdown NEAT1 also significantly suppressed H2O2-induced intracellular ROS production and malondialdehyde (MDA) content, but elevated the glutathione (GSH) activity of H2O2-treated cells. Also, it is demonstrated that si-NEAT1 greatly inhibited H2O2-induced phosphorylation of NF-кB p65 and p38 MAPK. Conclusions This study confirmed that knockdown NEAT1 attenuated H2O2-induced damage in HLECs, and inhibited the oxidative stress and apoptosis of HLECs via regulating nuclear factor-kappa B (NF-κB) p65 and p38 MAPK signaling. It may provide a potential target for clinical treatment of cataracts.