Titanium particle-induced inflammasome in human gingival epithelial cells

Area of Science:

• Oral biology
• Immunology
• Biomaterials science

Background:

• Peri-implantitis poses a significant clinical challenge.
• Titanium particles are common in dental implants and may influence peri-implant tissues.
• The NLRP3 inflammasome is implicated in inflammatory responses.

Purpose of the Study:

• To investigate the impact of titanium particles on human oral epithelial cells.
• To determine the role of the nucleotide-binding domain and leucine-rich repeat protein (NLRP) 3 inflammasome in titanium particle-induced inflammation.
• To explore the involvement of reactive oxygen species (ROS) in this process.

Main Methods:

• Ca9-22 human gingival epithelial cells were exposed to titanium particles.
• Cell viability was assessed using MTT assay.
• Gene expression (COX2, TGF-β1, NLRP1, NLRP3, CASP1, AIM2) and IL1β secretion were quantified.
• ROS production was measured using an ROS assay kit.

Main Results:

• Titanium particles maintained high cell viability (>75%) across tested concentrations.
• Dose-dependent increases in mRNA expression of COX2 and TGF-β1 were observed.
• NLRP3, CASP1 mRNA expression, and IL1β secretion increased after titanium particle exposure.
• Titanium particles elevated ROS production, which was mitigated by N-acetyl-l-cysteine, reducing NLRP3 and IL1β levels.

Conclusions:

• Titanium particles activate the NLRP3 inflammasome in oral epithelial cells.
• Reactive oxygen species (ROS) play a key role in mediating titanium particle-induced NLRP3 inflammasome activation.
• These findings offer insights into the pathogenesis of peri-implantitis.