Immune responses of human dental pulp stem cells in lipopolysaccharide‐induced microenvironment

Abstract

This study aimed to investigate the effect of inflammatory stimuli on dental pulp stem cells (DPSCs) by assessing their proliferation and expression of genes as well as proteins in lipopolysaccharide (LPS)-induced microenvironment (iDPSCs). DPSCs were first characterized for their mesenchymal properties prior to challenging them with a series of LPS concentrations from 12 to 72 h. Following to this, their proliferation and inflammatory based genes as well as protein expression were assessed. iDPSCs had demonstrated significant expression of mesenchymal markers. Upon exposure to LPS, the viability dropped distinctly with increasing concentration, as compared to control (P < 0.05). The expression of pro-inflammatory genes such as interleukin 6, interleukin 8 were augmented with exposure to LPS (P < 0.05). Similarly, cytokines like tumour necrosis factor (TNF) α and interleukin 1α had increased in dose dependant manner upon LPS exposure (P < 0.05). Our results suggest that LPS concentration between 1 and 2 μg/mL demonstrated inflammation induction in DPSCs that may simulate inflamed microenvironment of dental pulp in clinical scenario. Thus, optimizing iDPSCs secretome profile could be a promising approach to test various regenerative protocols in inflamed microenvironment.

Pulp capping materials modulate the balance between inflammation and regeneration

“…In order to evaluate in vitro inflammatory mediators secreted in damaged and inflamed pulp tissue, pulp fibroblasts have been injured and/or stimulated with Gram positive lipoteichoic acid (LTA) and/or Gram negative lipopolysaccharide (LPS). Quantification of the pro-inflammatory released mediators showed that IL-6, IL-8, IL1␣ and Tumor Necrosis Factor-␣ (TNF-␣) secretion increased in LPS-stimulated human DPSC [45]. Application of CSC has been shown to modulate pro-inflammatory mediator secretion.…”

Lipopolysaccharide upregulates the proliferation, migration, and odontoblastic differentiation of NG2+ cells from human dental pulp in vitro

“…Caries and pulpitis are major dental diseases that result from bacterial penetration (Kim et al, ). As the main component of the bacterial membrane, lipopolysaccharide (LPS) induces defensive inflammatory responses in the pulp (Bindal et al, ). In several experiments, LPS has been used to form a model of inflammation (Lee et al, ; Ko et al, ; Lertchirakarn and Aguilar, ).…”

Immunomodulatory Properties of Dental-Derived Mesenchymal Stem Cells

“…TLR-3 agonist augments immunosuppressive potential of DPSCs and dental follicle stem cells, whereas TLR-4 agonist augments immunosuppressive properties of dental follicle stem cells but inhibits those of DPSCs [181]. Different bacterial lipopolysaccharides induce production of proinflammatory mediators IL-6, IL-8 or MCP-1 in PDLSCs and DPSCs [16,[182][183][184]. TLR-2 and TLR-4 agonists fail to induce the expression of IDO-1 on protein level in PDLSC, but TLR-2 agonist enhances IFN-γ-induced IDO-1 expression [16].…”