Gene expression profiles in human dental pulp stem cells treated short-term with lipopolysaccharides before and after osteoinduction

Objectives: Dental pulp stem cells (DPSCs) are essential for reparative dentinogenesis following damage or infection. DPSCs surrounding the blood vessels in the central region of the dental pulp actively proliferate after tooth injury and differentiate into new odontoblast-like cells or odontoblasts to form reparative dentin. However, the signaling pathways involved in undifferentiated and osteodifferentiated DPSCs under inflammatory conditions remain unclear. This study aimed to compare the expression profiles of immortalized undifferentiated and osteo-differentiated human DPSCs (hDPSCs) treated with and without lipopolysaccharide (LPS) to elucidate the molecular regulatory mechanisms involved in inflammatory conditions.

Methods: We investigated the differences between undifferentiated and osteodifferentiated hDPSCs in response to LPS. RNA-seq analyses of undifferentiated and osteodifferentiated hDPSCs were performed with and without LPS.

Results: Whole-transcriptome profiling revealed distinct differences in the expression patterns of LPS-treated undifferentiated and osteodifferentiated DPSCs. Death-associated protein kinase 1 levels downregulated in LPS-treated osteodifferentiated cells, inhibiting apoptosis and enhancing cell survival. After LPS treatment, osteodifferentiated DPSCs exhibited higher expression levels of various inflammatory cytokines and chemokines than undifferentiated DPSCs.

Conclusion: This study provides valuable transcriptomic data as a critical resource for uncovering potential therapeutic targets to enhance cell survival and regulate inflammation within the dental pulp. By elucidating the key molecular mechanisms and identifying specific gene expression changes linked to inflammatory and immune responses, these findings provide significant insights into osteo-differentiated hDPSCs.