Periodontal Specific Differentiation of Dental Follicle Stem Cells into Osteoblast, Fibroblast, and Cementoblast

The dental follicle is a source of dental follicle stem cells (DFCs), which have the potential to differentiate into the periodontal lineage. DFCs therefore are of value in dental tissue engineering. The purpose of this study was to evaluate the effect of growth factor type and concentration on DFC differentiation into periodontal specific lineages. DFCs were isolated from the human dental follicle and characterized for the expression of mesenchymal markers. The cells were positive for CD-73, CD-44, and CD-90; and negative for CD-33, CD-34, and CD-45. The expression of CD-29 and CD-31 was almost negligible. The cells also expressed periodontal ligament and cementum markers such as periodontal ligament-associated protein-1 (PLAP-1), fibroblast growth factor-2 (FGF-2), and cementum protein-1 (CEMP-1), however, the expression of osteoblast markers was absent. Further, the DFCs were cultured in three different induction medium to analyze the osteoblastic, fibroblastic, and cementoblastic differentiation. Runt-related transcription factor 2 (RUNX-2), alkaline phosphatase (ALP) activity, alizarin staining, calcium quantification, collagen type-1 (Col-1), and osteopontin (OPN) expression confirmed the osteoblastic differentiation of DFCs. DFCs cultured in recombinant human FGF-2 (rhFGF-2) containing medium showed enhanced PLAP-1, FGF-2, and COL-1 expression with increasing concentration of rhFGF-2 which thereby confirmed periodontal ligament fibroblastic differentiation. Similarly, DFCs cultured in recombinant human cementum protein-1 (rhCEMP-1) containing medium showed enhanced bone sialoprotein-2 (BSP-2), CEMP-1, and COL-1 expression with respect to rhCEMP-1 which confirmed cementoblastic differentiation. The expression of osteoblast, fibroblast, and cementoblast-related genes of DFCs cultured in induction medium was enhanced in comparison to DFCs cultured in noninduction medium. Thus, growth factor-dependent differentiation of DFCs into periodontal specific lineages was proved by quantitative analysis.