Pluripotent Stem Cell Markers and microRNA Expression May Correlate with Dental Pulp Stem Cell Viability and Proliferation Rates

Abstract

Background: Recent evidence has demonstrated that dental pulp stem cells (DPSC) may represent a source of pluripotent progenitors capable of differentiating into many cell and tissue types. Although microRNAs are known to modulate differentiation and function in human dental tissues, much of this research has focused selectively on tooth development. The primary objective of this study was to evaluate the expression of microRNA in dental pulp stem cell isolates to compare with classical biomarkers of cellular phenotypes and pluripotency. Materials and Methods: Using eight previously isolated and characterized DPSC isolates, growth and viability were evaluated and RNA was extracted for mRNA screening. DPSC biomarker and microRNA expression were analyzed for comparison with cellular phenotypes. Results: Evaluation of the growth and proliferation rates of each cell line resulted in the categorization of DPSC isolates into rapid, intermediate, and slow doubling times, which demonstrated higher viability among the most rapidly proliferating DPSCs. Analysis of DPSC biomarkers (Oct-4, Sox-2, NANOG) revealed an association with total live cell count, while microRNA expression (miR-27, miR-218, miR-124, and miR-16) appeared to be more closely associated with cellular viability. Conclusions: Although this study was limited to a small number of DPSC isolates, these results suggest a more thorough investigation and evaluation of biomarkers and microRNA expression may be necessary to elucidate the associations and complex interconnections with DPSC viability, proliferation, differentiation, and pluripotency.