Probing the salivary proteome for prognostic biomarkers in response to non-surgical periodontal therapy.

AIM: This prospective study investigated the salivary proteome before and after periodontal therapy. MATERIALS AND METHODS: Ten systemically healthy, non-smoking, stage III, grade C periodontitis patients underwent non-surgical periodontal treatment. Full-mouth periodontal parameters were measured, and saliva (n = 30) collected pre- (T0), and one (T1) and six (T6) months post-treatment. The proteome was investigated by label-free quantitative proteomics. Protein expression changes were modelled over time, with significant protein regulation considered at false discovery rate <0.05. RESULTS: Treatment significantly reduced bleeding scores, percentages of sites with pocket depth ≥5 mm, plaque and gingival indexes. One thousand seven hundred and thirteen proteins were identified and 838 proteins (human = 757, bacterial = 81) quantified (≥2 peptides). At T1, 80 (T1 vs. T0: 60↑:20↓), and at T6, 118 human proteins (T6 vs. T0: 67↑:51↓) were regulated. The salivary proteome at T6 versus T1 remained stable. Highest protein activity post- versus pre-treatment was observed for cellular movement and inflammatory response. The small proline-rich protein 3 (T1 vs. T0: 5.4-fold↑) and lymphocyte-specific protein 1 (T6 vs. T0: 4.6-fold↓) were the top regulated human proteins. Proteins from Neisseria mucosa and Treponema socranskii (T1 vs. T0: 8.0-fold↓, 4.9-fold↓) were down-regulated. CONCLUSIONS: Periodontal treatment reduced clinical disease parameters and these changes were reflected in the salivary proteome. This underscores the potential of utilizing saliva biomarkers as prognostic tools for monitoring treatment outcomes.

m-nitrobenzyl alcohol supercharging reagent enhances the chromatographic separation and the charging of disulfide bond linked and His-tag peptides.

The linkages of disulfide bond (DSB) play important roles in protein stability and activity. Mass spectrometry-based (MS-based) techniques become accepted tools for DSB analysis in the recent decade. In the bottom-up approach, after enzyme digestion, the neighbouring amino acids of cysteines have great impacts on the physicochemical properties of resulting disulfide bond peptides, determining their retention behaviour on liquid chromatography (LC) and their MS ionization efficiency. In this study, the addition of supercharging reagent in LC mobile phase was used to examine the impact of supercharging reagent on the charge states of disulfide-bond peptides. The results showed that 0.1 % m-nitrobenzyl alcohol (m-NBA) in LC mobile phase increased the sensitivity and charge states of DSB peptides from our model protein, equine Interleukin-5 (eIL5), as well as the resolution of reversed-phase chromatography. Notably, also the sensitivity of C-terminal peptide with His-tag significantly improved. Our findings highlight the effectiveness of employing m-NBA as a supercharging reagent when investigating disulfide-linked peptides and the C-terminal peptide with a His-tag through nano-liquid chromatography mass spectrometry.

Protein Network Alterations in G-CSF Treated Severe Congenital Neutropenia Patients and Beneficial Effects of Oral Health Intervention.

PURPOSE: Severe congenital neutropenia (SCN) is a raredisorder characterized by diminished neutrophil levels. Despite granulocytecolony-stimulating factor (G-CSF) treatment, SCN patients remain still prone tosevere infections, including periodontal disease-a significant oral healthrisk. This study investigates the host proteome and metaproteome in saliva andgingival crevicular fluid (GCF) of G-CSF-treated patients. EXPERIMENTAL DESIGN: We used label-free quantitative proteomics on saliva and GCF samples from SCN patients before (n = 10, mean age: 10.7 ± 6.6 years) and after a 6-month oral hygiene intervention (n = 9,mean age: 11.6 ± 5.27 years), and from 12 healthy controls. RESULTS: We quantified 894 proteins in saliva (648 human,246 bacterial) and 756 proteins in GCF (493 human, 263 bacterial). Predominant bacterial genera included Streptococcus, Veillonella, Selenomonas, Corynebacterium, Porphyromonas, and Prevotella. SCN patients showed reduced antimicrobial peptides (AMPs) and elevated complement proteins compared tohealthy controls. Oral hygiene intervention improved oral epithelial conditionsand reduced both AMPs and complement proteins. CONCLUSIONS AND CLINICAL RELEVANCE: SCN patients have aunique proteomic profile with reduced AMPs and increased complement proteins, contributing to infection susceptibility. Oral hygiene intervention not onlyimproved oral health in SCN patients but also offers potential overall therapeuticbenefits.