Salivary Proteins as Biomarkers in Early Childhood Caries

Background: ECC is not only harmful to a child’s physical health but also has psychological and emotional effects. As an important host factor of caries susceptibility, saliva plays a significant role in the occurrence and development of caries. Saliva proteins may serve as useful biomarkers in predicting caries occurrence and prognosis. The relationship between salivary proteins and dental caries is yet to be well defined, and the biomarker information remains unclear.

Objective: The aim of the present study was to characterize the oral healthy and caries related salivary proteome and determine the differences in salivary protein expression of children without and with ECC. More specifically to determine which salivary proteins may be further used as biomarker for early childhood caries.

Methods: Whole unstimulated saliva samples were collected from 64 preschool children (age 3-5 years) with early childhood caries and caries-free. Saliva samples collected were further analyzed for salivary total protein concentrations and then established salivary proteome profiles by using SDS-PAGE that were stained by silver nitrate, Nano Liquid chromatography- tandem mass spectrometry (LC-MS/MS) was used for the proteomic analysis in selected SDS-PAGE gel bands and western blotting of specific antibodies was used to identify and quantify proteins in salivary samples.

Results: There is no statistically significant difference between the amount of protein and dental caries experience. In mixed saliva samples, which run by SDS-PAGE gel, variability was represented by the bands of 131kDa, 28 kDa, 26 kDa, 23 kDa, 17kDa and 12kDa. In western blot, the t-test of semi-quantification for specific proteins showed that there was no statistically significant difference between two groups，

Conclusion: The presence of ECC did not influence the total concentrations of salivary proteins，but some key screened proteins may be competent to be biomarkers for ECC.