Dental Pulp Cells Isolated from Teeth with Superficial Caries Retain an Inflammatory Phenotype and Display an Enhanced Matrix Mineralization Potential

Abstract

We have isolated dental pulp cells (DPCs) from three healthy (hDPCs) and three carious (cDPCs) donors and shown that compared to hDPCs cells isolated from superficial carious lesions show higher clonogenic potential; show an equivalent proportion of cells with putative stem cell surface markers; show enhanced matrix mineralization capability; have enhanced angiogenic marker expression and retain the inflammatory phenotype in vitro characteristic of superficial caries lesions in vivo. Our findings suggest that cDPCs may be used for further investigation of the cross talk between inflammatory, angiogenic and mineralization pathways in repair of carious pulp. In addition cells derived from carious pulps (almost always discarded) may have potential for future applications in mineralized tissue repair and regeneration.

Insulin-Like Growth Factor Axis Expression in Dental Pulp Cells Derived From Carious Teeth

“…Freshly extracted carious fully erupted third molars were collected from three adult patients (20–40 years of age) at the outpatient’s dental clinic of Leeds Dental Institute. Teeth were obtained through Leeds Dental and Skeletal tissue bank (under the approval of the Leeds University Dental Research Ethics Committee number 130111/AH/75), with patients’ informed consent (Alkharobi et al, 2017 ). Carious lesions in this study were chosen based on the depth of the decay in the dentin layer which was assessed in this group during the sectioning of the teeth.…”

“…This was assessed visually and using a WHO periodontal probe. Single cell suspensions were created by collagenase digestion of the isolated pulps as previously described (Alkharobi et al, 2016 , 2017 ). cDPCs at passage 4 were cultured in 6-well plates at 10 5 cells/well under basal conditions [α-MEM supplemented with 20% (v/v) FBS, 200 mM l -glutamine, and 100 unit/ml Pen Strep].…”

“…Interestingly, these cells showed high expression levels of some mesenchymal stem cell markers (Chen and Thouas, 2011 ) although there is some controversy in relation to their differentiation potential in comparison with cells isolated from normal pulp (McLachlan et al, 2004 ; Ma et al, 2012 ). cDPCs were found to have a higher mineralization potential as well as a higher expression of gene associated with osteogenesis and/or odontogenesis, compared to hDPCs (Alkharobi et al, 2017 ). The rate of dentin repair/regeneration is closely related to the population size of remaining vital odontoblasts or newly differentiated odontoblast-like cells.…”

“…In our previous study, we analyzed IGF axis gene expression in DPCs and demonstrated a novel role of IGFBP-2 and -3 in coordinating mineralized matrix formation (Alkharobi et al, 2016 ). A more recent study from our laboratory partially characterized DPCs from teeth with superficial caries (cDPCs) and showed that their potential to differentiate to a matrix mineralizing phenotype is enhanced by exposure to the mild inflammation characteristic of superficial caries (Alkharobi et al, 2017 ). In the current study, we aimed to determine whether the changes in IGF axis expression characteristic of differentiating hDPCs were also seen during differentiation of cDPCs.…”

Gene therapy and its applicability in Dentistry

“…With the advent of the genome sequencing of the Streptococcus mutans bacterium, it is possible to analyse the functionality, influence and interaction in the formation of caries. When affected by caries, the dentinal tissues act in defense of their dental pulp, stimulating the formation of a hard mineralized tissue, in other words, a reactionary dentin, difficulting the destruction of the vascularised subjacent pulpar tissue Studies try to analyse if, when stimulated by these pluri and multipotent cells, the odontoblasts can be sources of differentiation with potential for regeneration of the mineralised tissues [1,8].…”