Static magnetic fields promote osteogenesis via the lncRNA Gas5/miR-182/PKR molecular axis in rat osteoblasts and femoral defect models.

PURPOSE: Static magneticfields (SMF) stimulate osteogenesis, but the underlying mechanismremains unclear. This study investigated whether the lncRNAGas5/miR-182/PKR axis mediates SMF-enhanced osteogenic differentiation and bone repair.

MATERIALS AND

METHODS

Primary rat osteoblasts were induced with dexamethasone, ascorbic acid, and β-glycerolphosphate sodium, then exposed to 200 mT SMF or shamconditions. RT-PCR, Western blotting, ALP staining, alizarin redstaining, and dual-luciferase reporter assays were used to assessgene and protein expression, osteogenic markers, and lncRNAmiRNA binding. A femoral defect rat model was established, andtreated with SMF, lentiviral-mediated lncRNA Gas5 overexpression, or their combination. Bone formation was evaluated by Micro-CT, HE staining, and TRAP staining. Lentiviral vectors were used to over express lncRNA Gas5 in osteoblasts, and miR-182 mimicswere transfected to assess its role in osteogenesis.

RESULTS

SMF increased BMP2 expression, ALP activity, and calcification nodulesin osteoblasts, indicating enhanced osteogenic differentiation. SMF upregulated lncRNA Gas5 and PKR, while down regulating miR-182. Dual-luciferase assays confirmed lncRNA Gas5 spongesmiR-182, which directly targets PKR mRNA. LncRNA Gas5 over expression promoted osteogenic markers (BMP-2, Runx2, OSX, OCN) and mineralization, with SMF enhancing this effect synergistically. In femoral defect models, combined SMF and lncRNA Gas5 treatment increased bone formation, as shown by Micro-CT and histological analysis. miR-182 over expression suppressed osteogenic proteins, which was rescued by lncRNAGas5 co-expression, confirming its role as a negative regulatorin the axis.

CONCLUSIONS

SMF promotes osteogenesis and bone defect repair via the lncRNA Gas5/miR-182/PKR ceRNA pathway, revealing a novel epigenetic mechanism and a promising noninvasive therapy strategy.