Effect of lipoxin A4 on the osteogenic differentiation of periodontal ligament stem cells under lipopolysaccharide-induced inflammatory conditions.

Lipoxin A4 (LXA4) has been identified as the braking signal of inflammation, but the specific role of LXA4 in regulating the regenerative potential of periodontal ligament stem cells (PDLSCs) remains unclear. The aim of this study was to investigate whether and, if so, how LXA4 improves the osteogenic differentiation of PDLSCs in a lipopolysaccharide (LPS)-induced inflammatory environment. We detected the effects of LXA4 on the osteogenic differentiation of PDLSCs in vitro and explored the bone regenerative potential of LXA4-treated inflammatory PDLSCs in vivo using a calvarial critical sized defect model in male rats. RNA sequencing, real-time PCR and western blot were performed to elucidate the relevant potential mechanisms. Results showed that LXA4 promoted the proliferation, migration and osteogenic differentiation of PDLSCs in vitro, and effectively improved the impaired osteogenic capacity of PDLSCs induced by LPS both in vitro and in vivo. Mechanistically, LXA4 significantly promoted the PI3K/AKT phosphorylation under inflammatory conditions. Additionally, LY294002 (a PI3K inhibitor) blocked the effect of LXA4, suggesting that the PI3K/AKT pathway is a key signaling pathway that mediates the effect of LXA4 on the osteogenesis of inflammatory PDLSCs. These findings indicate LXA4 may be a promising strategy for periodontal regeneration using inflammatory PDLSCs.