AR-A014418, a glycogen synthase kinase-3b inhibitor, mitigates lipopolysaccharide- induced inflammation in rat dental pulp stem cells via NLR family pyrin domain containing 3 inflammasome impairment

Background/purpose: Cell pyroptosis and gingival inflammation have been implicated in periodontitis progression. Our previous study revealed that AR-A014418, a pharmaco-logical inhibitor of glycogen synthase kinase-38 (GSK-38), can enhance the migratory and osteogenic differentiation abilities of rat dental pulp stem cells (rDPSCs). The present study aimed to explore the effect of AR on the inflammation of rDPSCs.Materials and methods: The primary rDPSCs were isolated and identified by flow cytometry, as well as Oil red O and Alizarin Red S staining. The rDPSCs were cultured and exposed to lipopoly-saccharide (LPS) before treating them with different concentrations of AR-A014418. The cell viability was detected using the CCK-8 assay. The generation and secretion of pro-inflammatory cytokines (IL-18, TNF-a, L-18, and IL-6) were examined by qPCR and ELISA, respectively. To investigate the activation of the NLRP3 inflammasome, the expression levels of pro-caspase 1, cleaved caspase 1, as well as NLRP3 were analyzed by western blotting and immunofluorescence, respectively.Results: In the rDPSCs, LPS prohibited cell viability and enhanced the generation and secretion of pro-inflammatory cytokines. LPS upregulated NLRP3 and cleaved caspase-1 protein levels and promoted ASC speck formation in the rDPSCs. AR-A014418 administration effectively blocked the LPS-induced inflammation of the rDPSCs in a dose-dependent way. Mechanistically, AR-A014418 significantly restrained the up-regulation of NLRP3 and cleaved caspase-1 in LPS-treated rDPSCs.Conclusion: Collectively, our findings suggest that AR-A014418 significantly mitigates LPS-induced inflammation of rDPSCs by blocking the activation of the NLRP3 inflammasome.