RBP-J-mediated suppression of LINC00324 promotes ferroptosis via SLC3A2 in silica-induced pulmonary fibrosis

Silica-induced pulmonary fibrosis involves epithelial-mesenchymal transition(EMT) and ferroptosis, but the regulatory roles of long non-coding RNAs in these processes remain unclear. This study investigates the role of LINC00324 in ferroptosis and EMT which contribute to silica-induced pulmonary fibrosis.

A549 and BEAS-2B were exposed to SiO₂ (100 μg/mL, 24 h). Molecular analyses included chromatin immunoprecipitation (ChIP), dual-luciferase reporter assays, RNA immunoprecipitation, and functional rescue experiments. In vivo validation C57BL/6 mice were treated with intratracheal silica instillation (50 mg/kg) and lentiviral-mediated SLC3A2 overexpression (5 × 10⁷ TU), followed by histopathological/biochemical analyses at day 28.

Silica exposure transcriptionally suppressed LINC00324 via impaired RBP-J binding to its promoter region. LINC00324 overexpression mitigated silica-induced ferroptosis and EMT, while its knockdown aggravated ferroptosis and EMT. Further studies showed that LINC00324 played a regulatory role in ferroptosis and EMT through SLC3A2. RBP-J, as a transcription factor upstream of LINC00324, regulates ferroptosis and EMT in silica-induced pulmonary fibrosis through SLC3A2. In vivo, SLC3A2 overexpression alleviated silica-induced pulmonary fibrosis.

Collectively, the RBP-J/LINC00324/SLC3A2 pathway regulates ferroptosis -EMT coupling in silicosis. RBP-J regulates ferroptosis and EMT by binding to the promoter region of LINC00324 and regulating the downstream SLC3A2. Therapeutic targeting of this pathway may combat silica-induced pulmonary fibrosis.