Effect of Berberine on Osteogenic Differentiation of Human Periodontal Ligament Stem Cells in the Inflammatory Microenvironment through Modulation of FOXO1 Phosphorylation

The purpose of this study is to explore the effects of berberine (BBR) on osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) in inflammatory environments and the mechanisms involved. hPDLSCs were isolated from human periodontal membrane tissues and identified via flow cytometry detection by evaluating cell surface markers. hPDLSCs were intervened by using different concentrations of BBR, followed by assessing the cell activity for screening the optimal concentration of BBR for subsequent experiments. hPDLSCs cultured with or without osteogenic induction medium were induced by TNF-α and the optimal concentration of BBR, respectively, and the cells were grouped into control, TNF-α, BBR, and TNF-α + BBR groups. Cell proliferation, ALP activity, and osteogenic differentiation were assessed. The expression of RUNX2, OPN, FOXO1, and phosphorylated p-FOXO1 was also evaluated. Compared with the control group, the TNF-α group exhibited decreased cell activity, reduced ALP activity, impaired osteogenic differentiation, downregulated osteogenic proteins RUNX2 and OPN, and increased expression of p-FOXO1/FOXO1. Relative to the TNF-α group, the TNF-α + BBR group indicated increased cell activity, enhanced ALP activity, improved osteogenic differentiation, upregulated RUNX2 and OPN expression, and decreased p-FOXO1/FOXO1 expression. BBR enhances osteogenic differentiation of hPDLSCs in the inflammatory microenvironment via the inhibition of FOXO1 phosphorylation level.