METTL3 Promotes Osteogenic Differentiation of Human Periodontal Ligament Stem Cells Under the Inflammatory Microenvironment Through the miR-141-3p/ZEB1 Axis.

Periodontitis, a chronic inflammatory condition, often results in gum tissue damage and can lead to tooth loss. This study explores the role of methyltransferase-like 3 (METTL3) in promoting osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) within an inflammatory microenvironment. An inflammatory environment was simulated in hPDLSCs using lipopolysaccharide (LPS). Both adipogenic and osteogenic differentiation capacities of hPDLSCs were assessed. In LPS-treated hPDLSCs, METTL3 was overexpressed, and alkaline phosphatase (ALP) staining was performed alongside measurements of ALP activity, pro-inflammatory cytokines, METTL3, miR-141-3p, pri-miR-141, Zinc finger E-box binding homeobox 1 (ZEB1), runt-related transcription factor 2 (RUNX2), osteocalcin (OCN). N6-methyladenosine (m6A) and pri-miR-141 levels were quantified, and the binding of miR-141-3p to ZEB1 was analyzed. The results demonstrated that osteogenic differentiation in hPDLSCs was diminished under inflammatory conditions, coinciding with downregulated METTL3 expression. However, METTL3 overexpression enhanced osteogenic differentiation. METTL3 facilitated the conversion of pri-miR-141 into miR-141-3p via m6A modification, resulting in increased miR-141-3p levels, which in turn suppressed ZEB1 expression. Inhibition of miR-141-3p or overexpression of ZEB1 partially counteracted the positive effects of METTL3 on osteogenic differentiation. In conclusion, these findings suggest that METTL3-mediated m6A modification promotes osteogenic differentiation of hPDLSCs within an inflammatory microenvironment through the miR-141-3p/ZEB1 axis.