Roles of TLR2, TLR4, NOD2, and NOD1 in Pulp Fibroblasts
- 1 August 2009
- journal article
- Published by SAGE Publications in Journal of Dental Research
- Vol. 88 (8), 762-767
- https://doi.org/10.1177/0022034509341779
Abstract
Pulp fibroblasts express various pro-inflammatory mediators leading to marked infiltration of inflammatory cells in the progression of pulpitis. We hypothesized that pulp fibroblasts play roles in the recognition of invaded caries-related bacteria and the subsequent innate immune responses. We found clear expressions of TLR2, NOD1, and NOD2 and a faint expression of TLR4 in human dental pulp fibroblasts (HDPF) by RT-PCR and flow cytometry. We also observed that various pro-inflammatory mediators, including cytokines, chemokines, adhesion molecules, prostaglandin E2 and its key enzyme COX-2, not iNOS or caspase-1, were markedly up-regulated by stimulation with these TLR and NOD agonists. More over, the NOD2 agonist acted synergistically with the TLR2, not the TLR4, agonist to stimulate the production of pro-inflammatory mediators in HDPF. These findings indicate that TLR2, TLR4, NOD2, and NOD1 in HDPF are functional receptors, and NOD2 is a modulator of signals transmitted through TLR2 in pulpal immune responses, leading to progressive pulpitis.Keywords
This publication has 34 references indexed in Scilit:
- Immunohistochemical evaluation of endothelial cell adhesion molecules in human dental pulp: Effects of tooth preparation and adhesive applicationArchives of Oral Biology, 2007
- Update on the Adaptive Immune Responses of the Dental PulpJournal of Endodontics, 2007
- Innate Immune Responses of the Dental Pulp to CariesJournal of Endodontics, 2007
- Synergistic stimulation of human monocytes and dendritic cells by Toll-like receptor 4 and NOD1- and NOD2-activating agonistsEuropean Journal of Immunology, 2005
- Nod1 Detects a Unique Muropeptide from Gram-Negative Bacterial PeptidoglycanScience, 2003
- An essential role for NOD1 in host recognition of bacterial peptidoglycan containing diaminopimelic acidNature Immunology, 2003
- Nod2 Is a General Sensor of Peptidoglycan through Muramyl Dipeptide (MDP) DetectionJournal of Biological Chemistry, 2003
- Host Recognition of Bacterial Muramyl Dipeptide Mediated through NOD2Online Journal of Public Health Informatics, 2003
- Cytokine Induction byStreptococcus mutansand Pulpal PathogenesisInfection and Immunity, 2000
- Immunohistochemical study on the immunocompetent cells of the pulp in human non-carious and carious teethArchives of Oral Biology, 1995