Characterisation of Dental Pulp Cells Derived from Carious Teeth

This study investigated some characteristics of dental pulp stromal/stem cells (DPSCs) isolated from healthy teeth (hDPSCs) compared to DPSCs isolated from teeth with shallow carious lesions (cDPSCs) with a view to the use of both cell types in hard tissue engineering strategies. Osteogenic differentiation was investigated using appropriate histochemical staining and osteogenic marker expression (ALPL, OC, RUNX-2). In addition, angiogenic (VEGFR-2, PECAM-1) and inflammatory gene markers (TLR-2, TLR-4) were investigated together with the secretion of the pro-inflammatory cytokines (IL-6 and IL-8). The activity of the pro-osteogenic IGF axis was also investigated in hDPSCs and cDPSC cultures. cDPSCs exhibited significantly higher clonogenic potential, and possess a higher proportion of cell that express mesenchymal stem cell markers (CD146+, CD90+ and CD105+, CD45-, CD31-) compared with hDPSCs. Evidence also suggested that cDPSCs had a greater osteoblastic differentiation potential than hDPSCs. cDPSCs expressed higher levels of inflammatory markers than hDPSCs together with higher concentrations of IL-6 and IL-8 in conditioned medium indicative of retention of a carious phenotype following cell isolation and culture. Finally functional examination of the IGF axis suggested a role for insulin-like growth factor binding proteins-2 and -3 (IGFBP-2 and -3) in the osteogenic differentiation of DPSCs. Therefore cDPSCs are comparable to hDPSCs in terms of their osteogenic potential and the inflammatory environment of cDPSCs may offer a promising cell source for future mineralised tissue repair and regeneration.