2022, Vol. 26 ›› Issue (26): 4107-4112

Regulating the expression of nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome-related molecules in dental pulp fibroblasts under inflammation

Zhang Ansheng1, Zhang Haiou2, Ni Longxing1     

Abstract: BACKGROUND: Nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 inflammasome is an important inflammatory factor for cellular defense against various pathogens, which has been confirmed to be expressed in dental pulp fibroblasts. However, the mechanisms underlying the transcription regulation of NOD-like receptor protein 3 inflammasome in dental pulp fibroblasts under inflammation remains unclear.
OBJECTIVE: To elucidate the mechanisms underlying the transcription regulation of NOD-like receptor protein 3 inflammasome in dental pulp fibroblasts under inflammation.
METHODS: The 4th generation dental pulp fibroblasts were divided into six groups. Group A was cultured normally without any treatment. Group B was simulated with lipopolysaccharide for 6 hours. Group C was treated with a specific inhibitor of Toll-like receptor 4 for 1 hour, and then it was also treated with a mixed solution of Toll-like receptor 4 specific inhibitor and lipopolysaccharide for 6 hours. Group D was treated with a specific inhibitor of myeloid differentiation factor 88 for 1 hour, and then treated with a mixed solution of specific inhibitor of myeloid differentiation factor 88 and lipopolysaccharide for 6 hours. Group E was treated with a specific inhibitor of nuclear factor κB for 1 hour, and then treated with a mixture solution of specific inhibitor of nuclear factor κB and lipopolysaccharide for 6 hours. Group F was treated with a negative control of myeloid differentiation factor 88 specific inhibitor for 1 hour, and then treated with a mixed solution of myeloid differentiation factor 88 specific inhibitor negative control and lipopolysaccharide for 6 hours. Real-time polymerase chain reaction was used to detect the mRNA expression of NOD-like receptor protein 3, Caspase-1 and interleukin 1β. Western bolt was used to detect the expression of NOD-like receptor protein 3 and Caspase-1. And enzyme linked immunosorbent assay was used to detect the release level of interleukin 1β.
RESULTS AND CONCLUSION: Compared with group A, the mRNA expression of NOD-like receptor protein 3, Caspase-1 and interleukin 1β was increased in group B (P < 0.05), while compared with group B, the mRNA expression of NOD-like receptor protein 3 and interleukin 1β was decreased in groups C-E (P < 0.05), and the mRNA expression of Caspase-1 was also decreased in group C (P < 0.05). Compared with group A, the protein expression of NOD-like receptor protein 3 and Caspase-1 was increased in group B (P < 0.05), while compared with group B, the protein expression of NOD-like receptor protein 3 was decreased in groups C-E (P < 0.05), and the protein expression of Caspase-1 was also decreased in group C (P < 0.05). Compared with group A, the level of interleukin 1β was increased in group B (P < 0.05), while compared with group B, the levels of interleukin 1β were decreased in groups C-E (P < 0.05). All these findings indicate that lipopolysaccharide upregulates the expression of NOD-like receptor protein 3 and interleukin 1β in dental pulp fibroblasts through the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-kappa B signaling pathway.
Key words: dental pulp fibroblasts, innate immunity, nucleotide-binding oligomerization domain-like receptor 4, nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome, signaling pathway, interleukin 1β, nuclear factor κB