O‐GlcNAcylation of TLR4 inhibits osteogenic differentiation of periodontal ligament stem cells

Abstract

AbstractBackgroundToll‐like receptor 4 (TLR4)‐mediated inflammatory responses are associated with diabetes and periodontitis, which are dysregulated by O‐GlcNAcylation.ObjectiveThis study aimed to investigate the effects of O‐GlcNAc transferase (OGT)‐mediated TLR4 O‐GlcNAcylation on the osteogenesis of periodontal ligament stem cells (PDLCs).MethodsPDLCs were treated with high glucose (HG) to establish a cell model. Osteogenic differentiation was evaluated using western blotting, an alkaline phosphatase activity assay, and an alizarin red S staining assay. The regulation of OGT on the O‐GlcNAcylation of TLR4 was analyzed using co‐immunoprecipitation, immunoprecipitation, western blotting, and immunofluorescence staining.ResultsThe results showed that HG inhibited osteogenic differentiation and promoted inflammatory response. Knockdown of OGT promoted osteogenic differentiation of HG‐treated PDLCs. OGT interacted with TLR4 and increased the O‐GlcNAcylation and protein levels of TLR4 in the cytomembrane of PDLCs. Moreover, silenced TLR4 reversed the effects on osteogenic differentiation induced by OGT in HG‐treated PDLCs.ConclusionO‐GlcNAcylation of TLR4 induced by OGT suppresses osteogenic differentiation of PDLCs after HG stimulation. The findings suggest a promising strategy for treating DP.