Project description:Childhood caries is an extremely common childhood chronic disease, affecting 60–90% of children in industrialized countries. It results in lesions in both the primary and permanent dentitions, hospitalizations and emergency room visits, high treatment costs, loss of school days, diminished ability to learn increases the risk of caries in adulthood. Streptococcus mutans is a key bacteria in caries development. While multiple caries risk factors have been identified, significant interpersonal variability not explained by known risk factors still exists. The immune system generates a personal antibody repertoire that helps maintain a balanced and healthy oral microbiome. Using mass-spectrometry, we probed in an hypothesis-free manner which S. mutans proteins are identified by antibodies of children with low and high DMFT (decayed, missing, filled teeth) scores. We identified a core set of proteins, recognized by the immune system of most individuals. This set was enriched with proteins enabling bacterial adhesion, and included glucosyltransferases and glucan-binding proteins known to be important for S. mutans cariogenicity. To explore the physiological relevance of these findings, we tested the ability of saliva from caries free individuals in preventing S. mutans from binding to the tooth surface. Indeed, saliva from individuals with caries free prevented S. mutans binding to teeth. These findings map the S. mutans proteome targeted by the immune system and suggest that inhibiting tooth attachment is a primary mechanism used by the immune system to maintain oral balance and prevent caries. These findings provide new insights into the role of the immune system in maintaining oral health and preventing caries development.
Project description:Predictive Value of MicroRNAs in the Progression of Oral Leukoplakias Comparison of 10 samples from non-progressive leukoplakias (did not turn into oral squamous cell carcinoma), with 10 samples from progressive leukoplakias (turned into oral squamous cell carcinoma w/in 5 yrs)
Project description:Patients with oral preneoplastic lesion (OPL) have high risk of developing oral cancer. Although certain risk factors such as smoking status and histology are known, our ability to predict oral cancer risk remains poor. The study objective was to determine the value of gene expression profiling in predicting oral cancer development. Gene expression profile was measured in 86 of 162 OPL patients who were enrolled in a clinical chemoprevention trial that used the incidence of oral cancer development as a prespecified endpoint. The median follow-up time was 6.08 years and 35 of the 86 patients developed oral cancer over the course. Gene expression profiles were associated with oral cancer-free survival and used to develope multivariate predictive models for oral cancer prediction. We developed a 29-transcript predictive model which showed marked improvement in terms of prediction accuracy (with 8% predicting error rate) over the models using previously known clinico-pathological risk factors. Based on the gene expression profile data, we also identified 2182 transcripts significantly associated with oral cancer risk associated genes (P-value<0.01, single variate Cox proportional hazards model). Functional pathway analysis revealed proteasome machinery, MYC, and ribosomes components as the top gene sets associated with oral cancer risk. In multiple independent datasets, the expression profiles of the genes can differentiate head and neck cancer from normal mucosa. Our results show that gene expression profiles may improve the prediction of oral cancer risk in OPL patients and the significant genes identified may serve as potential targets for oral cancer chemoprevention. Gene expression profile was measured in 86 of 162 OPL patients who were enrolled in a clinical chemoprevention trial that used the incidence of oral cancer development as a prespecified endpoint. The median follow-up time was 6.08 years and 35 of the 86 patients developed oral cancer over the course. Gene expression profiles were associated with oral cancer-free survival and used to develope multivariate predictive models for oral cancer prediction.
Project description:<p><strong>Purpose:</strong> Dental caries is characterized by a dysbiotic shift at the biofilm-tooth surface interface, yet comprehensive biochemical characterizations of the biofilm are scant. We used metabolomics to identify biochemical features of the supragingival biofilm associated with early childhood caries (ECC) prevalence and severity. </p><p><strong>Methods:</strong> The study’s analytical sample comprised 289 children ages 3-5 (51% with ECC) who attended public preschools in North Carolina and were enrolled in a community-based cross-sectional study of early childhood oral health. Clinical examinations were conducted by calibrated examiners in community locations using ICDAS criteria. Supragingival plaque collected from the facial/buccal surfaces of all primary teeth in the upper-left quadrant were analyzed using Ultra Performance Liquid Chromatography-tandem Mass Spectrometry. Associations between individual metabolites and 18 clinical traits (based on different ECC definitions and sets of tooth surfaces) were quantified using Brownian distance correlations (dCor) and linear regression modeling of log2-transformed values, applying a False Discovery Rate multiple testing correction. A tree-based pipeline optimization tool (TPOT)-machine learning process was used to identify the best-fitting ECC classification metabolite model. </p><p><strong>Results:</strong> There were 503 named metabolites identified, including microbial, host and exogenous biochemicals. Most significant ECC-metabolite associations were positive (i.e., upregulations/enrichments). The localized ECC case definition (ICDAS≥1 caries experience within the surfaces from which plaque was collected) had the strongest correlation with the metabolome (dCor p=8x10-3). Sixteen metabolites were significantly associated with ECC after multiple testing correction, including: fucose (p=3.0x10-6) and N-acetylneuraminate (p=6.8x10-6) with higher ECC prevalence; catechin (p=4.7x10-6) and epicatechin (p=2.9x10-6) with lower. Catechin, epicatechin, imidazole propionate, fucose, 9,10-DiHOME, and N-acetylneuraminate were among the top 15 metabolites in terms of ECC classification importance in the automated TPOT model. </p><p><strong>Conclusion:</strong> These supragingival biofilm metabolite findings provide novel insights in ECC biology and can serve as the basis for the development of measures of disease activity or risk assessment.</p>