Salivary annexin A1: A candidate biomarker for periodontitis.

AIM: To compare the salivary proteomic profile of periodontitis-affected (PA) parents and their offspring to periodontally healthy (PH) dyads in the pursuit of possible biomarkers for early diagnosis of this disease. MATERIALS AND METHODS: Unstimulated saliva samples collected from 17 pairs of PA or PH individuals and their children were submitted to mass spectrometric analyses followed by proteomic analyses. Primary PA fibroblasts were triggered towards having an inflammatory response, and an immunoenzymatic assay of its supernatant was performed to validate the obtained data. RESULTS: ANXA1, KRT4, GSTP1, HPX, A2M and KRT13 were lower in PA parents and their children, and IGHG1, CSTB, KRT9, SMR3B, IGHG4 and SERPINA1 were higher. ANXA1 presented the highest fold change, 7.1 times less produced in children of PA parents, and was selected as a potential biomarker for periodontitis. The in vitro assay also showed lower ANXA1 production by cells of PA patients. CONCLUSION: Before any clinical sign of periodontal loss, descendants of PA patients have an altered proteomic profile compared to PH individuals, presenting a lower abundance of ANXA1. This protein is suggested as a potential biomarker for periodontitis.

IL10 promoter rs6667202 polymorphism is functional in health but not in grade c periodontitis patients: A pilot study.

BACKGROUND AND OBJECTIVE: Previous studies have demonstrated an association between the IL10 promoter rs6667202 (C > A) single-nucleotide polymorphism (SNP) and grade C, stage 3 or 4 periodontitis (Perio4C) in the Brazilian population, where the altered A allele was detected more frequently in these patients. However, no functional analysis of this variation has yet been performed. Thus, the objective of this preliminary study was to evaluate the functionality of rs6667202 in gingival fibroblasts (GFs) of individuals with Perio4C and with periodontal health (PH) stimulated with Aggregatibacter actinomycetencomitans protein extract (AaPE). METHODS: Patients with PH and Perio4C were segregated according to their genotype (AA, AC, or CC), and a biopsy was performed to establish the culture of the GFs. After GFs exposure to AaPE at 5 µg/ml for 1.5 h, RNA was extracted to analyze IL10 expression by qPCR. Aliquots of the cell's supernatant were subjected to immunoenzymatic analysis (MAGpix) to detect interleukin-10 (IL-10). RESULTS: In PH, the genotypes AA and AC are related to less expression of IL10 (p = 0.027 and p < 0.0001) and less production of IL-10 (p = 0.002 and p = 0.001), when compared to CC. In Perio4C, there was no statistical difference between the genotypes (p > 0.05), although a lower IL-10 expression and release compared with PH CC was seen (p = 0.033 and p < 0.001). CONCLUSION: The rs6667202 SNP is functional in PH, as it decreases the expression and production of IL-10. In Perio4C, other factors may be masking its action by altering the IL-10's response.

Novel co-initiators of polymerization: Cytotoxicity profile and modulation of inflammatory mediators in human dental pulp stem cells.

OBJECTIVES: The aim of this study was to assess the cytotoxicity of novel polymerization co-initiators and their effect on cytokine release from human dental pulp stem cells (hDPSCs), comparing them with commonly used co-initiators. METHODS: Cells were isolated from the dental pulp of healthy human third molars. The new co-initiators, namely HDa1, HD4, HD1, and MHPTm, were evaluated and compared with the compounds dimethylaminoethyl amine benzoate (EDAB) and 2-(dimethylamino)ethyl methacrylate (DMAEMA). These compounds were diluted in dimethylsulfoxide (DMSO) at concentrations ranging from 1 to 8 mM. hDPSCs were seeded onto 96-well plates and incubated for 48 h. Subsequently, the cells were exposed to different concentrations of the co-initiators mentioned for 24 h. After this period, the culture medium was removed, and mitochondrial metabolism was evaluated using the MTT assay, while cytokine release (IL-1ß, IL-6, IL-8, IL-10, TNF-α) was analyzed by the MAGPIX assay. Cells without exposure to the tested compounds served as controls. The data were analyzed using one-way ANOVA and Tukey's test. RESULTS: The compounds showed low toxicity, with 8 mM concentration causing the most significant reduction in mitochondrial metabolism. MHPTm was the most toxic co-initiator tested (compound bearing an amine functionality). All compounds up-regulated TNF-α, IL-10, IL-6, and IL-8, with HD4 exhibiting the most pronounced increase in IL-6 and IL-8. SIGNIFICANCE: The newly proposed co-initiators demonstrated reduced impact on mitochondrial metabolism, comparable to some traditional co-initiators. Despite their lower toxicity, HD4 increased IL-6 and IL-8 release, suggesting its potential involvement in triggering an inflammatory reaction, particularly in the short term.

Immune response characterization of primary gingival fibroblasts from Grade C periodontitis patients.

BACKGROUND: Grade C, Stage 3-4 Periodontitis (Perio4C) is a rapidly destructive disease caused by an unequilibrated immune response that starts after the primary contact of the periodontopathogens with the gingival tissue. However, it is still unclear how this imbalanced response initiates and what is the role of the connective tissue cells in the progression of this disease. Thus, this study aims to assess the local immune response of Perio4C patients through the exposure of primary gingival fibroblast cells (GFs) with Aggregatibacter actinomycetemcomitans protein extract (AaPE) and the quantification of the inflammatory cytokines interleukin (IL)-4, IL-17, tumor necrosis factor (TNF)-α, IL-1ß, interferon (IFN)-γ, and IL-10 super-family members (IL-10, IL-19, and IL-24) secreted by them. METHODS: Gingival biopsies from nine periodontally health (PH) and eight Perio4C patients were harvested, and the primary culture of GFs was obtained. The cells were exposed to AaPE (5 and 20 µg/ml) and 12-myristate 13-phorbol acetate and ionomycin - calcium salt (PMA). The supernatant was collected after 1.5 and 3 h, and a cytokine panel was evaluated. RESULTS: Clustering analysis indicated dissimilar and stimuli-dependent cytokine production between Perio4C and PH subjects. Perio4C GFs presented lower production of IL-4, TNF-α, IFN-γ, IL-17, IL-10, IL-24, and IL-19, while IL-1ß levels were similar to the PH group, leading to a disruption in the pro-/anti-inflammatory cytokine ratio (p < 0.05). IL-1ß and IL-10 super-family were the most discriminative representants for PH and Perio4C, respectively. CONCLUSION: GFs from individuals with Perio4C tended to hypo-respond to stimulation with AaPE, producing lower concentrations of some pro- and anti-inflammatory molecules, trending to develop a pro-inflammatory extracellular environment.

Predicted functional and taxonomic analysis of subgingival biofilm of Grade C periodontitis in young patients under maintenance therapy.

BACKGROUND: In Grade C periodontitis in young patients (PerioC-Y), the functional roles of the subgingival community after years of periodontal treatment are still underexplored. This study evaluated the taxonomic and predicted functional content of the subgingival microbiome of PerioC-Y patients under supportive periodontal therapy (SPT). METHODS: Clinical and microbiological data from subgingival biofilm were assessed from 10 PerioC-Y patients at two time points: at baseline and after 5.7 ± 1.3 years of SPT. This was compared with 15 patients without a history of periodontitis. The V1-V3 and V4-V5 regions of the 16S rRNA were sequenced using the Illumina Miseq. Microbial composition was evaluated by the core microbiome, and alpha- and beta-diversity. The microbiome functional content was predicted using Picrust2, and the gene differential abundance was analyzed with DESeq2. RESULTS: Clinical improvements were seen in PerioC-Y-SPT. Differences in ß-diversity between PerioC-Y and health were observed (health x PerioC-Y-baseline, P = 0.02; health x PerioC-Y-SPT, P = 0.05). Moreover, although ß-diversity did not statistically change between baseline and SPT in PerioC-Y, the microbial correlation evidenced increased Streptococcus and decreased Treponema network contributions during SPT. Based on predicted functional data, treatment induced a reduction in genes related to flagellar protein and signal transduction in PerioC-Y. However, compared with healthy individuals, some genes remained more highly abundant in PerioC-Y-SPT, such as quorum sensing and efflux pump transporters. CONCLUSION: Despite clinical improvements and a shift in taxonomic composition, the PerioC-Y patients' periodontal treatment was not enough to reach a similar microbiome to patients without disease experience. Some functional content in this biofilm remained altered in PerioC-Y regardless of disease control.