METTL3 potentiates osteogenic differentiation of bone marrow mesenchymal stem cells via IGF2BP1/m6A/RUNX2

Maxillofacial bone defect is a critical obstacle for maxillofacial tumors and periodontal diseases. The osteogenic differentiation of bone marrow mesenchymal stem cells BMSCs is critical for maxillofacial osteogenesis and functional reconstruction. Here, our study focused on the functions and mechanism of N⁶-methyladenosine during BMSCs osteogenic differentiation BMSCs.

Biofunctions of BMSCs were detected using ALP activity and alizarin red S staining assays. The molecular interaction within RNA/protein was identified by RNA immunoprecipitation and/or methylation immunoprecipitation.

Results indicated that m⁶A 'writer' METTL3 upregulated during the osteogenic differentiation of BMSCs upon osteogenic induction. Functionally, assays' results revealed that METTL3 overexpression promoted the osteogenic differentiation of BMSC, while METTL3 knockdown repressed the osteogenic differentiation. Mechanistically, results revealed that RUNX2 mRNA was a m⁶A-methylated target by METTL3 at its 3'-UTR. Moreover, m⁶A reader IGF2BP1 recognized the m⁶A site on RUNX2 mRNA to enhance its stability.

In conclusion, our findings revealed the novel roles of METTL3 in BMSCs osteogenic differentiation via the IGF2BP1/m⁶A/RUNX2 signaling axis of m⁶A-dependent manner, providing a potential therapeutic target for maxillofacial bone defects treatment.