Fluocinolone acetonide partially restores the mineralization of LPS‐stimulated dental pulp cells through inhibition of NF‐κB pathway and activation of AP‐1 pathway

Abstract

BACKGROUND AND PURPOSEFluocinolone acetonide (FA) is commonly used as a steroidal anti-inflammatory drug. We recently found that in dental pulp cells (DPCs) FA has osteo-/odonto-inductive as well as anti-inflammatory effects. However, the mechanism by which FA induces these effects in DPCs is poorly understood. EXPERIMENTAL APPROACHThe effect of FA on the mineralization of DPCs during inflammatory conditions and the underlying mechanism were investigated by real-time PCR, Western blot, EMSA, histochemical staining, immunostaining and pathway blockade assays. KEY RESULTSFA significantly inhibited the inflammatory response in LPS-treated DPCs not only by down-regulating the expression of pro-inflammation-related genes, but also by up-regulating the expression of the anti-inflammatory gene PPAR-γ and mineralization-related genes. Moreover, histochemical staining and immunostaining showed that FA could partially restore the expressions of alkaline phosphatase, osteocalcin and dentin sialophosphoprotein (DSPP) and mineralization in LPS-stimulated DPCs. Real-time PCR and Western blot analysis revealed that FA up-regulated DSPP and runt-related transcription factor 2 expression by inhibiting the expression of phosphorylated-NF-κB P65 and activating activator protein-1 (AP-1) (p-c-Jun and Fra-1). These results were further confirmed through EMSA, by detection of NF-κB DNA-binding activity and pathway blockade assays using a NF-κB pathway inhibitor, AP-1 pathway inhibitor and glucocorticoid receptor antagonist. CONCLUSIONS AND IMPLICATIONSInflammation induced by LPS suppresses the mineralization process in DPCs. FA partially restored this osteo-/odonto-genesis process in LPS-treated DPCs and had an anti-inflammatory effect through inhibition of the NF-κB pathway and activation of the AP-1 pathway. Hence, FA is a potential new treatment for inflammation-associated bone/teeth diseases. AbbreviationsALP, alkaline phosphatase; AP-1, activator protein-1; DPCs, dental pulp cells; DSPP, dentin sialophosphoprotein; FA, fluocinolone acetonide; OCN, osteocalcin; p-P65, phosphorylated NF-κB P65; RUNX2, runt-related transcription factor 2; t-RA, all-trans-retinoic acid

In vivo analysis of the presence of heme oxygenase‐1, transcription factor Jun‐D and CD90+/CD73+/CD105+/CD45‐ cells in the pulp of bleached teeth

“…A previous study with dental pulp cells reported the presence of other transcription factors of AP‐1 (Fra‐1 and c‐Jun) in untreated cells (Liu et al . ). Further studies should be performed to understand the location and performance of Jun‐D during odontoblastic differentiation.…”

Fluocinolone Acetonide Is a Potent Synergistic Factor of TGF-β3–Associated Chondrogenesis of Bone Marrow–Derived Mesenchymal Stem Cells for Articular Surface Regeneration

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Ameliorative Effects of Neurolytic Celiac Plexus Block on Stress and Inflammation in Rats with Partial Hepatectomy

“…The results of western blotting showed that NCPB treatment can significantly inhibit the degradation of IκB and decrease the expression of p65, as well as decreasing the nuclear translocation of p65. The expressions of c-Jun are correlated to the activity of AP-1 [22], our work demonstrated that NCPB can decrease the expressions of c-Jun of the macrophages, and suppress its nuclear translocation. In addition, our results also indicated that NCPB can also decrease the DNA binding activities of NF-κB and AP-1.…”