Concomitant multipotent and unipotent dental pulp progenitors and their respective contribution to mineralised tissue formation

Abstract

Upon in vitro induction or in vivo implantation, the stem cells of the dental pulp display hallmarks of odontoblastic, osteogenic, adipogenic or neuronal cells. However, whether these phenotypes result from genuine multipotent cells or from coexistence of distinct progenitors is still an open question. Furthermore, determining whether a single cell-derived progenitor is capable of undergoing a differentiation cascade leading to tissue repair in situ is important for the development of cell therapy strategies. Three clonal pulp precursor cell lines (A4, C5, H8), established from embryonic ED18 first molars of mouse transgenic for a recombinant plasmid adeno-SV40, were induced to differentiate towards the odonto/osteogenic, chondrogenic or adipogenic programme. Expression of phenotypic markers of each lineage was evaluated by RT-PCR, histochemistry or immunocytochemistry. The clones were implanted into mandibular incisors or calvaria of adult mice. The A4 clone was capable of being recruited towards at least 3 mesodermal lineages in vitro and of contributing to dentin-like or bone formation, in vivo, thus behaving as a multipotent cell. In contrast, the C5 and H8 clones displayed a more restricted potential. Flow cytometric analysis revealed that isolated monopotent and multipotent clones could be distinguished by a differential expression of CD90. Altogether, isolation of these clonal lines allowed demonstrating the coexistence of multipotential and restricted-lineage progenitors in the mouse pulp. These cells may further permit unravelling specificities of the different types of pulp progenitors, hence facilitating the development of cell-based therapies of the dental pulp or other cranio-facial tissues.

Dual Role of the Trps1 Transcription Factor in Dentin Mineralization

“…Cell Culture-Preodontoblastic 17IIA11 cells (42,43) were maintained in standard DMEM (Invitrogen) with 5% FBS (Thermo Fisher Scientific, Logan, UT) and 100 units/ml penicillin and 100 g/ml streptomycin (Cellgro, Manassas, VA) at 37°C and 8% CO 2 . For the osteo-odontogenic differentiation experiments, cells were plated at 5 ϫ 10 5 cells per well of a 6-well plate.…”

“…Trps1 in the physiology and pathology of odontoblast-regulated mineralization, we employed the 17IIA11 cell line (17A cells) derived from mouse odontoblasts (42,43). 17A cells are a good model to study molecular mechanisms of odontoblast-mediated mineralization, because they express key transcription factors as well as enzymes and matrix proteins required for mineralization (42).…”

From pulpal stem cells to tooth repair: an emerging field for dental tissue engineering

“…Upon in vitro appropriate induction, A4 cells can undergo unidirectional differentiation along either odonto/osteogenic, chondrogenic, or adipogenic lineage. Another clonal pulp cell line, H8, is a monopotent progenitor that displays a restricted potential of differentiation towards the odontoblastic fate (Lacerda-Pinheiro et al 2012). In vivo, after implantation in a mouse incisor or rat molar, both A4 and H8 cells have the capacity to induce spatio-temporally controlled osteodentin formation and thus to promote efficient tooth repair (Lacerda-Pinheiro et al 2012;Harichane et al 2011).…”

“…Another clonal pulp cell line, H8, is a monopotent progenitor that displays a restricted potential of differentiation towards the odontoblastic fate (Lacerda-Pinheiro et al 2012). In vivo, after implantation in a mouse incisor or rat molar, both A4 and H8 cells have the capacity to induce spatio-temporally controlled osteodentin formation and thus to promote efficient tooth repair (Lacerda-Pinheiro et al 2012;Harichane et al 2011). Thus, the isolation of A4 and H8 cell lines that both belong to the odontogenic lineage but differ in their differentiation potential demonstrates that multipotential and restricted lineage progenitors coexist in the dental pulp (Lacerda-Pinheiro et al 2012).…”

“…In vivo, after implantation in a mouse incisor or rat molar, both A4 and H8 cells have the capacity to induce spatio-temporally controlled osteodentin formation and thus to promote efficient tooth repair (Lacerda-Pinheiro et al 2012;Harichane et al 2011). Thus, the isolation of A4 and H8 cell lines that both belong to the odontogenic lineage but differ in their differentiation potential demonstrates that multipotential and restricted lineage progenitors coexist in the dental pulp (Lacerda-Pinheiro et al 2012). These two independent, stable, and homogenous pulp cell lines with precursor properties represent useful tools to search for the intrinsic properties of odontogenic stem cells.…”