Comparative gene expression analysis of human dental pulp cells from maxillary and mandibular teeth

Abstract

Objective : Given the anatomical and locational differences between the maxillary and mandibular teeth, it is possible that there are differences in gene expression patterns of dental pulp cells within those teeth. This study evaluates and compares the gene expression profiles of the maxillary and mandibular human teeth with the aim of finding differences in gene expression patterns of dental pulp cells by RNA-Sequencing technique. Methods : The upper and lower premolar and molar teeth obtained from the same participant were employed. Two pairs of opposing premolar teeth and two pairs of opposing molar teeth were isolated, cultured, and subjected for RNA sequencing. RNA-Seq Alignment and RNA-Seq Differential Expression were used to analyze gene expression profile. Quantitative RT-PCR was performed to confirm the result obtained from RNA-Sequencing. Results : RNA sequencing demonstrated that 19,372 genes out of 27,914 in total were expressed. The top expression genes were FN1, COL1A1, COL1A2, ACTB and EEF1A1. In DPSCs of posterior teeth (premolar and molar), only PITX1 gene had a significant higher expression (exhibiting 26.47 or 89-fold change) in the lower teeth compared to the upper teeth (64-fold change in premolar teeth and 116-fold change in molar teeth). Conclusion : We showed that PITX1 gene had a significant higher expression in the lower teeth compared to the upper teeth and this difference in PITX1 level was more evident in the molars compared to premolars.