Blockade of TLR2 Inhibits Porphyromonas gingivalis Suppression of Mineralized Matrix Formation by Human Dental Pulp Stem Cells

Abstract

Introduction Human dental pulp stem/progenitor cells (hDPSC) can differentiate into odontoblast-like cells and express dentin sialophosphoprotein (DSPP) and osteocalcin (OCN); thus, they may be used to regenerate dentin. However, residual bacterial components in the root canal may suppress this activity. Purpose This study investigated the effect of a Porphyromonas gingivalis component on the expression of DSPP and OCN by stimulated hDPSCs and the influence of blockade of TLR2-mediated P. gingivalis host recognition. Methods Stimulated hDPSCs were exposed to varying concentrations of P. gingivalis lipopolysaccharide (LPS), and the expression of DSPP and OCN was measured. Similar groups of stimulated hDPSCs were exposed to TLR2 blocking agents before exposure to LPS. Results hDPSCs exposed to 5, 10, and 20 µg/mL LPS exhibited a dose-dependent reduction in the expression of DSPP (3.19 ± 0.18, 2.60 ± 0.49, and 1.15 ± 0.29, respectively) and OCN (3.51 ± 1.18, 2.60 ± 0.67 and 1.66 ± 0.89, respectively). The expression of DSPP and OCN after exposure to 20 µg/mL of LPS was significantly lower than measured for unexposed stimulated cells (analysis of variance and post hoc Tukey test, P < .05). The blockade of TLR2 using an extra- and intracellular agent affected DSPP (4.67 ± 0.97 and 5.29 ± 1.66, respectively) and OCN (5.25 ± 1.69 and 5.82 ± 2.38, respectively) expression at levels comparable to stimulated cells unexposed to 20 µg/mL LPS (6.32 ± 2.47 and 4.70 ± 1.60 for DSPP and OCN, respectively). Conclusions The suppressing effect of P. gingivalis on mineralized matrix formation by hDPSCs is confirmed, and this suppression can be moderated by TLR2 blockade.

Tetra- and Penta-Acylated Lipid A Structures of Porphyromonas gingivalis LPS Differentially Activate TLR4-Mediated NF-κB Signal Transduction Cascade and Immuno-Inflammatory Response in Human Gingival Fibroblasts

“…There is a strong activation of NF-κB pathway in response to P. gingivalis LPS 1690 with reference to a weak activation of P. gingivalis LPS 1435/1449 , illustrating the significant role of lipid A structure in activation of NF-κB pathway. The host response of dental pulp cells to P. gingivalis LPS is also elicited via TLR2/IKK signal transduction axis [53]. Although, it seems that P. gingivalis LPS, being different from canonical E. coli LPS, may have some propensity to bind TLR2, some have previously argued that it could be due to the contamination of lipoprotein or other components during LPS extraction.…”

Static Magnetic Field Attenuates Lipopolysaccharide‐Induced Inflammation in Pulp Cells by Affecting Cell Membrane Stability

“…Of these cells, DPSCs exhibit multipotent differentiation ability; thus, tissue engineering study has gradually come to focus on DPSCs [ 3 , 4 ]. In addition, DPSCs were reported to have excellent potential for dentin repair and tooth regeneration [ 5 ]. Given this potential use in tissue engineering, investigations into the treatment of bacterial induced pulpitis and tooth preservation are increasingly important for regenerative medicine.…”

“…Until now, however, the only way to prevent pain is by removing the pulp via root canal treatment or tooth extraction. In this regard, several scholars have focused their aim on investigating the immunoresponse of DPSCs and dental pulp cells (DPCs) [ 5 – 9 ].…”

“…It is now known that the coreceptor of LPS formed by the Toll-like receptor 4 (TLR4) and CD14 is the binding site for signaling LPS-induced cytotoxicity [ 11 , 12 ]. Even though DPSCs and DPCs express LPS receptors (TLRs) on their membrane surfaces [ 5 , 7 , 9 ], it is hard to bring medicines to the infected pulp tissue because these sites are surrounded by hard tissue. For the successful regeneration of pulp tissue in a root canal, neutralizing the adverse effects of residual LPS remains a challenge for scientists [ 5 ].…”

Angiotensina II na modulação de células de papila apical humana in vitro

“…A citocina IL-1 β não foi produzida em 1 e 24 horas no sobrenadante das Elegeu-se a concentração de estímulo de LPS a 1µg/mL por verificar nessa concentração um aumento da expressão de CCL-2 nas células da papila apical no presente estudo, sendo que aumento da expressão dessa quimiocina tem sido associado ao maior recrutamento de células de defesa para sítios inflamatórios, principalmente monócitos (53). Esta concentração em outros estudos também foi capaz de induzir resposta biológica em células mesenquimais indiferenciadas incluindo CPAs (130)(131)(132). Logo, a concentração de 1µg/mL foi utilizada para os ensaios da terceira e quarta fase da pesquisa.…”