Proteomics - The research frontier in periodontics

Abstract

Periodontitis is an inflammatory condition resulting from the interplay between the infectious agents and host factors. Various protein molecules play a vital role in the initiation, progression and severity of periodontal diseases. The study of proteins as biomarkers in periodontal diseases has been highlighted during the last few years. In periodontitis multiple bacteria derived (e.g. collagen degrading enzymes, elastase like enzymes etc) and host derived mediators (eg. PGE2, TNF, IL1, IL6, MMP's etc) expressed in the saliva and gingival crevicular fluid, can be utilized as diagnostic markers for the disease. Another significant development regarding human genes and proteins has been the discovery of potential new drugs for the treatment of periodontal diseases. Therefore the information of the proteins involved in the pathogenesis of periodontal diseases can be utilized for its diagnosis, prevention and treatment.

Keywords: Biomarkers; Genome; Periodontitis; Porphyromonas gingivalis; Proteome.

Fig. 1

Flow diagram showing the contrast between traditional, gene-to-protein analysis and global analysis of gene & protein expression.

Fig. 2

The flow chart illustrates critical steps along the midline, from protein separation, identification followed by sequence analysis. Along with the major steps, analysis of post-translational modifications, as well as functional and interactive proteomics provides a new direction for the future possibilities for the biologists focusing on the periodontium.

Fig. 3

Flow diagram emphasizes the basic steps prior to mass spectrometry which includes biological sample preparation, protein separation, protease digestion, peptide separation and analysis.

Fig. 4

Overview of pathogenesis of periodontal disease and the role of biological mediators. LPS – Lipopolysaccharide from gram negative bacteria on tooth surface. PMN – Polymorphonuclear leukocyte. PDL – Periodontal ligament. PGE ₂, TNF-α & IL-1β – Prostaglandin E ₂, Tumor necrosis factor & Interlukin. RANKL – Receptor activator of nuclear factor kappa B ligand mediates osteoclastogenesis. ICTP – Pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (bone specific markers).