SALIVARY EXOSOME PROTEOME AS A NEW TOOL FOR THE DIAGNOSIS OF ORAL DISEASES

Abstract

Introduction, aim: Exosomes generated by the endosomal pathway are released by the exocytosis into the extracellular space, including saliva. They contain nucleic acids, proteins and lipids that are transported to different parts of the body. They participate in intercellular communication, whether they support or disrupt various physiological processes. The aim of this work was to verify the efficiency of the ultracentrifugation method of isolation of exosomes from saliva, to exctract and identify proteins contained therein, with an emphasis on exosomal proteins related to diseases of the oral cavity or systemic diseases with manifestations in the oral cavity. Methods: Exosomes were isolated from full unstimulated human saliva by repeated centrifugation steps with washing in phosphate buffer followed by methanol/chloroform protein precipitation. Proteins were identified by a bottom-up approach using mass spectrometry with pre-separation by liquid chromatography. Results: The identified proteins were classified according to protein classes, molecular functions and biological processes. The most identified proteins were of the protein classes: cytoskeletal proteins, defense/immune proteins and structural proteins and proteins responsible for catalytic activity and structural molecular activity. Conclusions: Proteins have been classified into groups based on their molecular function and biological processes in which they participate in the human body. Some proteins/family of proteins have been identified that may be of interest in investigating the etiology of some oral diseases e.g. annexin A1, zymogen granular protein 16 homologue B, mucin-5B, Ig lambda-3 chain C region, Ig kappa chain C region, Ig alpha-2 chain C region and Ig alpha-1 chain C region.

Keywords

• saliva
• exosomes
• proteomics
• oral diseases