Differentiation of stem cells derived from carious teeth into dopaminergic-like cells.

AIM: To investigate whether dental pulp stem cells from carious teeth (DPSCs-CT) can differentiate into functional dopaminergic-like (DAergic) cells and provide an alternative cell source in regenerative medicine. METHODOLOGY: Dental pulp stem cells from healthy (DPSCs) and carious teeth (DPSCs-CT) were isolated from young donors. Both cell lines were expanded in identical culture conditions and subsequently differentiated towards DAergic-like cells using pre-defined dopaminergic cocktails. The dopaminergic efficiencies were evaluated both at gene and protein as well as at secretome levels. RESULTS: The efficiency of DPSCs-CT to differentiate into DAergic-like cells was not equivalent to that of DPSCs. This was further reflected in both gene and protein generation whereby key neuronal markers such as nestin, NURR1 and beta-III-tubulin were expressed significantly lower as compared to differentiated DPSCs (P < 0.05). In addition, expressions of transcriptomes related to neurogenesis revealed downregulation of more than 50% of the genes as compared to differentiated DPSC (P < 0.05). Amongst the notable genes were those from the transcription factors family (FLNA, MEF2C, NEUROG2), signalling pathway family (DLL1, Notch1, TGF-ß1), neuro-inducer family (BDNF) and cell communication family (APBB1). CONCLUSIONS: DPSCs-CT were able to differentiate into DAergic-like cells but not as efficiently as DPSCs. As such, prior to use in regenerative medicine, stem cells from any source should be thoroughly investigated beyond conventional benchmarks such as that proposed by the International Society for Cellular Therapy (ISCT).

Basal expression of growth-factor-associated genes in periodontal ligament stem cells reveals multiple distinctive pathways.

AIM: To identify and compare the expression level of growth-factor-associated genes in human periodontal ligament (PDL) stem cells with dental pulp stem cells isolated from deciduous teeth as well as to assess their suitability in regenerative dentistry. METHODOLOGY: Periodontal ligament and dental pulp stem cells were isolated from deciduous teeth. Human both cells lines were expanded in identical culture condition, and their differentiation profile and cell surface antigen were compared. In addition, growth factor associated genes profiles were assessed using PCR array. RESULTS: Stem cells from deciduous dental pulp (SCD) and periodontal ligament cultures were capable of proliferating and mutually expressed the specific phenotype profile of human mesenchymal stem cells (MSCs). In osteogenic cultures, calcium nodules were observed by day 21 in PDL and dental pulp stem cells. In adipogenic cultures, both cell populations showed positive Oil Red O staining by day 21. Likewise, in chondrogenic cultures, both stem cells expressed the formation of proteoglycan. Interestingly, the expression of growth factor analysis revealed a higher propensity of PDL stem cells towards angiogenesis, osteogenesis and neurogenesis as compared to dental pulp stem cells. CONCLUSIONS: The data suggest the PDL stem cell population can be utilized as potential sources for cell-based therapies in regenerative dentistry.