Proteomic profile of non-bacterial proteins in periodontal pockets: a pilot study.

Aim: In this study, we attempted to identify the proteins involved in periodontitis comparing the proteomic profile of interproximal pocket tissue affected by the periodontal lesion with interproximal healthy tissue in the same subject, in sites where no periodontopathogenic bacteria were detectable. Material and Methods: Using specific inclusion and exclusion criteria, we enrolled 15 subjects affected by severe chronic periodontitis. The subjects presenting at least one intrabony defect (next to a healthy interproximal site to be included in the flap design) suitable for treatment by osseous respective surgery, were considered eligible for this study. Biopsies of connective tissue were harvested from the intrabony component of the defect and from healthy tissue (from the secondary flap) and immediately frozen at –80°C. A two-dimensional gel electrophoresis system was used to detect differences in protein expression between pathologic and healthy tissue and protein identification by LC-MS/MS analysis was performed. Results: Six proteins (tropomyosin α-4 chain, 14-3-3 protein z/δ, putative heat shock protein HSP 90-β, peroxiredoxin-1, fatty acid binding protein, S100-A9) displayed a higher while five a lower (annexin A1, actin cytoplasmatic-1, carbonic anhydrase-2, Ig K chain C region and flavin reductase) protein expression level in pathologic tissue compared with healthy tissue. Conclusion: The highlight of proteins involved in the immunological and cytokine signaling cascade mediation or in connective and epithelial regeneration and differentiation shows that the pathogenic process is active in periodontal sites also in absence of periodontopathogen microbiota. Besides, proteomic analysis could be considered very useful in studying the pathogenesis of periodontitis. Abstract N: P0224 ISSN:1600-051X (Electronic).