Changes in viability, cell cycle, mineralization function and gene expression in dental pulp progenitor cells, induced by bacterial lipopolysaccharide

Abstract

Dental pulp repair processes due to conservative procedures are, in general, affected by the conflicts between possible microorganisms at the area of exposure and cells responsible for differentiation and production of mineralized tissue. However, the literature lacks information on how bacterial products affect these processes directly. The purpose of this study will be to evaluate the bacterial lipopolysaccharide (E. coli LPS) effects on dental pulp progenitor cells, regarding the expression of differentiation genes and function of mineralization, using basal conditions and pre-induced mineralization by osteogenic media. Characterized progenitor cells will be initially submitted to different LPS concentrations (0,2 a 200 ng/ml), to observe cytotoxic (viability, cell cycle and apoptosis) effects and alkaline phosphatase activity. The minimal concentration to observe phosphatase enzymatic activity with no cell viability changes will be used to assess the functional mineralization effects (nodule formation by alizarin red staining), besides the gene expression for odontoblast differentiation markers (DSPP and DMP-1) and a mineralization marker (Runx2). Quantitative data will be statistically analyzed by ANOVA, complemented by the Tukey's test (p<0.05). (AU)