Reactive oxygen species-dependent release of damage-associated molecular patterns from human gingival epithelial Ca9-22 cells during butyrate or propionate exposure

Abstract

Treating the gingival epithelial Ca9-22 cell with butyrate, a short-chain fatty acid (SCFA) produced by bacteria within mature dental plaque, induces necrotic cellular death. In this report, it was examined whether SCFA-mediated cellular death is accompanied by a release of damage-associated molecular patterns (DAMPs). In addition, the role of reactive oxygen species (ROS) in the release of DAMPs was evaluated. Human gingival epithelial Ca9-22 cells were treated with butyrate or propionate. The amounts of dead cells were then measured using SYTOX-green dye. Released DAMPs were detected by western blot. The role of ROS scavengers, ascorbic acid and N-acetylcysteine, on DAMPrelease was evaluated. Dose and time-dependent induction of Ca9-22 cell death was observed during butyrate and propionate treatments. This was accompanied by the release of DAMPs. Ascorbic acid or N-acetylcysteine reduced cellular death and inhibited DAMP-release induced by exposure to butyrate or propionate. These data collectively suggest that SCFA-induced death of gingival epithelial Ca9-22 cells and accompanying release of DAMPs are dependent on ROS.

Proof-of-Principle Study Suggesting Potential Anti-Inflammatory Activity of Butyrate and Propionate in Periodontal Cells

“…Butyrate pushes pyroptosis of gingival epithelial cells [ 44 ] and inhibits expression of lymphangiogenic factors in HSC3 cells [ 45 ]. Further, in the gingival epithelial Ca9-22 cell line, butyrate- or propionate-exposure cell death accompanied apoptotic and autophagy signaling [ 46 ] and the release of damage-associated molecular patterns [ 47 ]. Even though epithelium is a passive barrier protecting the underlying tissues in response to injury or infection, the epithelial cells can become a source of inflammatory mediators [ 48 ].…”