Gingival Crevicular Fluid Peptidome Profiling in Healthy and in Periodontal Diseases.

Given its intrinsic nature, gingival crevicular fluid (GCF) is an attractive source for the discovery of novel biomarkers of periodontal diseases. GCF contains antimicrobial peptides and small proteins which could play a role in specific immune-inflammatory responses to guarantee healthy gingival status and to prevent periodontal diseases. Presently, several proteomics studies have been performed leading to increased coverage of the GCF proteome, however fewer efforts have been done to explore its natural peptides. To fill such gap, this review provides an overview of the mass spectrometric platforms and experimental designs aimed at GCF peptidome profiling, including our own data and experiences gathered from over several years of matrix-assisted laser desorption ionization/time of flight mass spectrometry (MALDI-TOF MS) based approach in this field. These tools might be useful for capturing snapshots containing diagnostic clinical information on an individual and population scale, which may be used as a specific code not only for the diagnosis of the nature or the stage of the inflammatory process in periodontal disease, but more importantly, for its prognosis, which is still an unmet medical need. As a matter of fact, current peptidomics investigations suffer from a lack of standardized procedures, posing a serious problem for data interpretation. Descriptions of the efforts to address such concerns will be highlighted.

Rapid Detection and Identification of Antimicrobial Peptide Fingerprints of Nasal Fluid by Mesoporous Silica Particles and MALDI-TOF/TOF Mass Spectrometry: From the Analytical Approach to the Diagnostic Applicability in Precision Medicine.

BACKGROUND: Antimicrobial peptides (AMP) play a pivotal role in innate host defense and in immune response. The delineation of new MS-based profiling tools, which are able to produce panels of AMP of the nasal fluid (NF), may be attractive for the discovery of new potential diagnostic markers of respiratory disorders. METHODS: Swabs collected NF from healthy patients and from patients with respiratory disorders. We used a fast procedure based on mesoporous silica particles (MPS) to enrich NF in its AMP component in combination with MALDI-TOF/TOF MS as a key tool for rapidly analyzing clinical samples. RESULTS: Reproducible MS peptide fingerprints were generated for each subject and several AMP were detected including (Human Neutrophil Peptides) HNPs, Statherin, Thymosin-ß4, Peptide P-D, II-2, ß-MSP, SLPI, Lysozyme-C, and their proteo-forms. In particular, Statherin, Thymosin-ß4, and Peptide P-D were accurately identified by direct MS/MS sequencing. Examples of applicability of this tool are shown. AMP fingerprints were obtained before and after a nasal polypectomy as well as before and post-treatment with azelastine/fluticasone in one case of allergic rhinitis. CONCLUSION: The potential of our platform to be implemented by new mesoporous materials for capturing a wider picture of AMP might offer an amazing opportunity for diagnostic clinical studies on individual and population scales.

An Analytical Method for Assessing Optimal Storage Conditions of Gingival Crevicular Fluid and Disclosing a Peptide Biomarker Signature of Gingivitis by MALDI-TOF MS.

PURPOSE: Gingival crevicular fluid (GCF) is an important diagnostic source of biomarkers for both periodontitis and gingivitis. However, GCF peptide signature may change depending on factors such as handling and storage. Here we propose a standardized methodology for GCF analysis by MALDI-TOF/TOF-MS in order to distinguish a characteristic peptide signature of gingivitis. EXPERIMENTAL DESIGN: The best storage/handling conditions which may ensure the stability of the endogenous peptidome in GCF is determined and then MALDI-TOF MS comparative analysis is performed. Reproducible GCF MALDI-TOF signatures between two groups of gingivitis (n = 10) and healthy (n = 10) subjects are compared. RESULTS: A pattern of five peptides resulted differentially expressed between gingivitis and healthy groups. Interestingly, among these biomarkers the C-terminal fragment of alpha-1-antitrypsin (AAT) namely C-36 peptide and two different PTMs of the full-length S100A9 protein are found. CONCLUSIONS AND CLINICAL RELEVANCE: The method described provides a rapid comparative analysis of GCF signatures between periodontally healthy and gingivitis subjects. A pattern based on the expression of endogenous peptides and their PTMs is identified in GCF as putative biomarkers of gingivitis. These findings improve the knowledge of the inflammatory, immune, and structural substrates which might have a key role in the pathogenesis of gingivitis.