miR-1246 regulates odontogenic differentiation of human dental pulp stem cells in an inflammatory microenvironment by targeting AXIN2: an in vitro study

OBJECTIVE: This study aimed to investigate the modulatory function of microRNA-1246 (miR-1246) in the odontogenic differentiation of human dental pulp stem cells (hDPSCs) under inflammatory conditions in vitro and to elucidate its underlying molecular mechanism. METHODS: An inflammatory state was replicated in vitro by treating hDPSCs with lipopolysaccharide (LPS). miR-1246 expression was modulated via transfection with its mimics or inhibitors. Cell proliferation, movement, and apoptosis were assessed. Odontogenic differentiation capacity was assessed via alkaline phosphatase (ALP) activity, Alizarin Red S (ARS) staining, and transcript levels by quantitative real-time quantitative real-time polymerase chain reaction (qRT-PCR), along with Western blotting. To validate the direct interaction between miR-1246 and AXIN2, a dual-luciferase reporter assay was employed. All experiments were performed in three independent biological replicates. RESULTS: miR-1246 overexpression significantly reduced inflammatory cytokine levels (IL-1β, P < 0.05; IL-6, P < 0.05; TNF-α, P < 0.001) and partially restored hDPSC proliferation (P < 0.01), migration (P < 0.001), and survival (reduced apoptosis rate, P < 0.001). It also significantly increased ALP activity (P < 0.001), mineralized nodule formation (P < 0.001), and the expression of odontogenic markers (NRP1, DSPP, DMP1). Mechanistically, miR-1246 directly targeted AXIN2, preventing AXIN2-mediated β-catenin degradation and promoting the Wnt/β-catenin pathway, elevating downstream factors such as Cyclin D1 and c-Myc. AXIN2 knockdown reproduced the differentiation-promoting effects of miR-1246, whereas AXIN2 overexpression diminished them. CONCLUSION: miR-1246 promotes the odontogenic differentiation of hDPSCs and partially counteracts the detrimental effects of inflammation in vitro by directly targeting and inhibiting AXIN2 expression, thereby stimulating the Wnt/β-catenin signaling cascade.