From the salivary proteome to the OralOme: comprehensive molecular oral biology

Objectives: There have been several efforts to identify the protein components of saliva. Some of these studies were conducted in healthy individuals and other in individuals with different oral and systemic disorders. However, a resource compiling and reviewing all of the proteins identified in proteomic studies is still lacking. The aim of this project is to develop such a resource. Design: The proteins identified by proteomic studies were compiled and all information concerning them was manually curated according to "IPI History search" and UniProt. Proteins were classified according to gene ontology using PANTHER. The involvement of each protein in disease was scrutinized using DAVID and a classification into protein disease classes was performed. Results: This survey of proteins in the oral cavity lead to the identification of 3397 non-redundant proteins, 605 altered in pathological conditions and 51 present only in disease. These proteins originate from different sources: 3115 from saliva, 990 from oral mucosa and 1929 from plasma. All protein sources contribute with different numbers and types of proteins to identical functions. However, each source produces specific proteins. Examples of the use of this proteomics database of saliva included the analysis of the changes in the proteome associated with periodontitis and a survey of systemic disease potential biomarkers in saliva. Conclusion: The database generated with this work and the information therein stands as a resource for investigators/clinicians studying the oral biology, searching for molecular disease markers, developing diagnostic and prognostic tests, and contributing to the discovery of new therapeutic agents.