Effect of Particulate Matter 2.5 on Primary Gingival Keratinocyte and Human Gingival Fibroblast Cell Lines.

Objective:  Particulate matter 2.5 (PM2.5), an important air pollution particle, has been previously studied for its effects on various normal and cancer tissues. However, research on the impact of PM2.5, specifically on normal cavity tissue, is still limited. This study aimed to assess the effects of PM2.5 on cell vitality, cell cycle, and apoptosis in PGK (normal oral keratinocyte) and HGF (human gingival fibroblast) cell lines.

Materials and methods:  The effect of PM2.5 was examined through cell vitality using the Cell Counting Kit-8 (CCK8) assay, while cell cycle and apoptosis were determined via flow cytometry. Cells incubated with 0.05% dimethyl sulfoxide were used as the negative control.

Results:  In a concentration-dependent manner, PM2.5 inhibited the proliferation of HGF and PGK cells. The half-maximal inhibitory concentration (IC50) of PM2.5 after 24 hours of incubation was 400 ng/µL for HGF cells and 100 ng/µL for PGK cells. This particulate matter arrested the cell cycles of both HGF and PGK cells at the G0/G1 phase. Additionally, PM2.5 was found to trigger apoptosis in both HGF and PGK cell lines and also cause necrosis in the PGK cell line at higher concentrations.

Statistical analysis:  Kruskal-Wallis tests were employed to evaluate all quantitative data.

Conclusion:  The findings indicated that PM2.5 decreases cell viability, halts cell cycle progression, and triggers apoptosis in normal oral cavity cell lines. Therefore, it is advisable to avoid PM2.5 exposure in order to mitigate potential health risks. To understand PM2.5-induced oral cellular damage, more research is needed.