METHODS: The expression of MRONJ-related miRNA in RANKL-induced RAW264.7 cells treated with BP was analyzed using qRT-PCR analysis. Bioinformatics techniques were applied to screen potential circRNAs. Tartrate-resistant acid phosphatase (TRAP) staining and bone resorption assays were used to examine the effect of mmu_circ_0001066 on osteoclastogenesis. Bioinformatics analysis, luciferase reporter assays, and Western blotting assays were performed to investigate the underlying mechanism.
RESULTS: Four MRONJ-related miRNAs were upregulated in BP-treated RAW264.7 cells, and the expression of mmu_circ_0001066 was negatively correlated with those of MRONJ-related miRNAs. Furthermore, the upregulation of mmu_circ_0001066 partially attenuated the inhibitory effect of BP on osteoclastogenesis in RAW264.7 cells. Mechanistically, upregulated miR-16 suppressed osteoclastogenesis and miR-16 inhibitor increased osteoclastogenesis. Furthermore, we have identified that miR-16 is a downstream effector of mmu_circ_0001066.
CONCLUSIONS: Our results suggest that mmu_circ_0001066 played an important role in the BP-mediated suppression of osteoclastogenesis, which lays a foundation for identifying mmu_circ_0001066 as a potential biomarker for MRONJ.