Butyrate stimulates the early process of the osteogenic differentiation but inhibits the biomineralization in dental follicle cells (DFCs).

Dental stem cells, especially dental follicle cells (DFCs) as precursor cells for the periodontium have interesting prospects for regenerative dentistry. During periodontitis, butyrate as a bacterial metabolite and inflammatory agent is often found in millimolar concentrations in periodontal pockets. This study evaluates the effects of butyrate on the proliferation and osteogenic differentiation of DFCs. We assessed cell viability/proliferation (BCA assay) and osteogenic differentiation (ALP activity, alizarin staining and RT PCR) of DFCs in vitro after butyrate supplementation. Butyrate concentrations of 20 mM or higher are toxic for DFCs. At a non-toxic concentration, butyrate promotes the expression of alkaline phosphatase and collagen type-1 but inhibits the formation of calcified nodules and the induction of RUNX2 and osteocalcin under osteogenic differentiation conditions. In conclusion, DFCs are resistant to physiological high concentrations of butyrate. Butyrate facilitates the osteogenic differentiation of DFCs in early stages but inhibits calcification at later stages of the differentiation process.

Lipopolysaccharide from Escherichia coli but not from Porphyromonas gingivalis induce pro-inflammatory cytokines and alkaline phosphatase in dental follicle cells.

OBJECTIVES: Dental follicle cells (DFCs) as periodontal precursor cells are the natural source for cellular therapies of periodontitis. Periodontitis is initiated after the infection of the periodontium with oral pathogens such as the Gram-negative bacteria Porphyromonas gingivalis. Lipopolysaccharide (LPS) is the major component of the outer membrane of gram-negative bacteria. Previous studies have shown that especially P. gingivalis LPS induces the expression of pro-inflammatory cytokines in PDL cells and disturbs the differentiation of dental stem cells. Our study investigated the administration of LPS to DFCs for the first time. MATERIALS AND METHODS: We evaluated cell proliferation (WST1 assay), expression of cytokines IL1ß, IL8 and IL6 (real-time RT-PCR) and the osteogenic differentiation of DFCs (ALP-activity and Alizarin red staining) in the presence of P. gingivalis LPS and Escherichia coli LPS. RESULTS: All tested pro-inflammatory cytokines were highly increased after E. coli LPS treatment. P. gingivalis LPS induces only the expression of IL8, but this expression was significantly lower than that after E. coli LPS administration. The ALP activity was significantly higher in DFCs after the administration of E. coli LPS than after administration of P. gingivalis LPS or under normal cell differentiation conditions. However, the mineralization was inhibited with LPS from both bacterial species. CONCLUSION: LPS disturbs osteogenic differentiation in DFCs. Moreover, the failure of pro-inflammatory cytokines induction in DFCs after the administration of P. gingivalis LPS differs greatly from that of PDL fibroblasts. These immunological properties of DFCs have to be considered for cellular therapies of periodontitis with DFCs.