Mitochondrial ROS Mediates the LPS-induced Pro-inflammatory Response in Gingival Fibroblast Cells

Objectives: In this study, we wanted to detect the function of mtROS on the expression of proinflammation cytokines in human gingival fibroblasts in response to LPS.
Methods: Gingival fibroblast cells were obtained from gingival tissues prepared from explants of human normal gingival tissues. HGFs derived from four donors were use to do the following experiments, and HGFs were used between the 3th and 8th passages.We treated HGFs with LPS obtained from Pg, and examined their inflammatory responses in the presence and absence of the mitochondrial targeted antioxidant mitoTEMPOL. The mtROS level was examined through fluorescence microscopy and microplate reader. The expression of pro-inflammatory cytokines such as interleukin-1β (IL-1β), interleukin-6（IL-6）, tumor necrosis factor-α（TNF-α）was examined by ELISA.
Results: (1) LPS enhanced mtROS production before enhancing expression of IL-1β, IL-6, TNF-α. (2) MitoTEMPOL suppressed all LPS-induced inflammatory responses.(LPS treated group vs MitoTEMPO blocking group, IL-1β: 753.97 vs 287.31, IL-6: 658.72 vs 291.86 TNF-α: 786.58 vs 375.51, p<0.05).
Conclusions: These results indicated that LPS increased the expression of cytokines in gingival fibroblasts mainly by elevating mtROS.