PBX1 attenuates H₂O₂-induced oxidant stress in human trabecular meshwork cells via promoting NANOG-mediated PI3K/AKT...

Oxidative stress-induced excessive extracellular matrix (ECM) deposition in trabecular meshwork (TM) tissue is considered the major pathological procedure of glaucoma. This study aimed to explore the role and regulatory mechanism of pre-B-cell leukemia transcription factor 1 (PBX1) in H₂O₂-induced human trabecular meshwork cells (HTMCs). Expressions of PBX1, NANOG, ECM, and pathway-related factors were detected by qRT-PCR and western blot. Cell viability and apoptosis of HTMCs were measured using CCK-8 and flow cytometry assays. Reactive oxygen species (ROS), superoxide dismutase (SOD), and L-glutathione (GSH) levels were detected to evaluate oxidative stress. Through luciferase reporter assay, the association between PBX1 and NANOG was verified. Results presented that PBX1 was significantly upregulated in H₂O₂-induced HTMCs. Functionally, PBX1 and NANOG promoted cell viability, inhibited cell apoptosis and ECM deposition, suppressed ROS accumulation, and enhanced the productions of SOD and GSH in H₂O₂-stimulated HTMCs, while PBX1 inhibition showed the opposite effects. In addition, PBX1 promoted the transcription of NANOG by upregulating the promoter activity of NANOG which activated the PI3K-AKT signaling pathway. What's more, the inhibitions of PI3K-AKT signaling pathway or NANOG reversed the protective effect of PBX1 on H₂O₂-stimulated HTMCs. In summary, our study firstly revealed that PBX1 attenuated the oxidative damage in HTMCs via regulating NANOG-mediated PI3K/AKT signaling, suggesting that PBX1 might be a potential treatment target for glaucoma patients.