Effect of statherin and Histatin peptides on cariogenic biofilm and on enamel demineralization

Abstract

Salivary proteins histatin and statherin, and its derived functional peptides RR14 and DR9, respectively, keep the homeostasis of teeth mineral composition by regulating de- and remineralizing processes and by inhibiting spontaneous precipitation of minerals on dental surface. Additionally, these proteins/peptides inhibit S. mutans adherence to the dental pellicle (DP). This knowledge brings the possibility to use synthetic duplicated (DR9/DR9) or hybrid (DR9/RR14) peptides to enhance caries control. Thus, the aim of this in vitro study is to determine how DR9/DR9 and DR9/RR14 peptides can modulate the proteome of S. mutans, controlling its adhesion to DP, the subsequent cariogenic biofilm development and the consequent enamel demineralization. To do so, two in vitro studies will be performed. In the first study, enamel slabs will be treated with the peptides to induce DP formation and then inoculated with S. mutans. The total, cell wall and intracellular bacterial proteomes of adhered and planktonic non-adhered S. mutans will be assessed after 2, 4 and 8 h. Also, the amount of bacteria adhered to enamel slabs after each time will be quantified. In the second study, it will be evaluated the effect of the peptides on cariogenic biofilm development. For this, enamel will be pre-treated with the peptides to induce DP formation and then biofilms will be additionally treated 2x/day with the peptides. Both the effect of the peptides on total, extracellular matrix and intracellular bacterial proteomes, and enamel demineralization will be evaluated. Proteomic analyses, for both studies, will be performed by Liquid Chromatography - Electrospray Ionization - Tandem Mass Spectrometry (LC-ESI-MS/MS). Additionally, for the second study, the concentration of extracellular insoluble and soluble polysaccharides, biomass and cellular viability will be evaluated in the biofilms. We expect the peptides will interfere with cariogenic biofilm initiation, development and the consequent enamel demineralization. (AU)