Gingival Enlargement Associated with Orthodontics Appliance Increases Protein Carbonylation and Alters Phosphorylation of Salivary Proteome

Abstract

Gingival enlargement is a common clinical sign in the gingival diseases associated with orthodontic treatment. Its biological mechanisms are not completely understood; nevertheless, the biochemical changes associated with these inflammatory and overgrowth processes could alter the post-translational protein modifications occurring in various locations within the mouth. Here, changes in the profiles of the carbonylated and phosphorylated proteins in saliva were examined in donors with gingival enlargement (seven men and seven women) and healthy donors (six men and eight women). The sociodemographic characteristics of both groups did not present significant differences. Carbonylation was measured by a quantitative immunoassay (Dot Blot), whereas the profiles of the phosphorylated proteins were visualized by SDS-PAGE with quercetin staining. Some phosphopeptides were also identified using a typical LC-MS-MS approach. Our results showed that gingival enlargement induced a significant increase in oxidative damage in salivary proteins. While a significant reduction in phosphorylation was observed at the stain level in SDS-PAGE, there was a slight increase in the number of phosphorylated proteins identified by MS in samples with gingival enlargement.