Project description:Human saliva has been commonly used as protein source in in vitro microbiological and biological assays to mimic the protein pellicle formation, termed acquired salivary pellicle, that precedes microbial and cell adhesion on surfaces exposed to the oral environment. However, saliva requires previous processing to remove food debris, microorganisms, and other molecules prior its use in microbiological and biological in vitro assays. For this purpose, 0.22 μm filtration, 0.45 μm filtration, and pasteurization methods have been commonly used, but the effect of these processing methods on the proteomic profile of saliva has not been tested experimentally. Stimulated human saliva was collected from 8 healthy volunteers and submitted to the following processes: non-processing (control), 0.22 μm filtration, 0.45 μm filtration, and pasteurization. The proteomic profile of non-processed saliva was compared with 0.22 μm filtered-, 0.45 μm filtered-, and pasteurized-saliva by liquid chromatography-mass spectrometry. The effect of processed saliva in microbial adhesion was tested using bacterial and fungus species, and in biological cell behavior using HaCaT immortalized human keratinocytes. Two hundred seventy-eight proteins were identified in non-processed saliva, 54 proteins (≈19%) were exclusive. Saliva processing reduced identified proteins to 222 (≈80%) for the 0.22 μm filtered saliva, 219 (≈79%) for the 0.45 μm filtered saliva, and 201 (≈72%) for the pasteurized saliva, compared to non-processed saliva. Although there were slight differences in the protein composition, the proteomic profile showed similar molecular functions and biological processes. The different saliva processing methods did not alter microbial adhesion (ANOVA, p>0.05). Interestingly, pasteurized saliva reduced keratinocytes cell viability. Saliva processing methods tested reduced the proteomic profile diversity of saliva, but maintained similar molecular functions and biological processes mediated by remaining proteins, not interfering on microbial adhesion and cell viability, except for pasteurization, which reduced cell viability.
Project description:We have performed gene expression microarray analysis to profile transcriptomic signatures between insulin resistance high risk subjects and insulin resistance low risk subjects Participants enrolled in this study were recruited in the overnight fasted state, then the collection and processing of glucose (fasting, 30, 60 and 120 minutes) and insulin from blood samples, hemoglobin A1c (HbA1c) , assessment of medical history, socio-demographic characteristics, lifestyle factors, blood pressure and anthropometric and body composition measurements were conducted. During baseline visit, participants were asked to refrain from eating, drinking and oral hygiene procedures for at least 1-hour prior to saliva collection.5 ml of unstimulated whole saliva samples were consistently collected, stabilized and preserved, the sample supernatants were reserved at -80°C prior to assay. Based on the homeostasis model assessment of insulin resistance (HOMA-IR), using the formula [HOMA-IR= (fasting glucose*fasting insulin)/405], participants were divided into 2 groups: IR high risk group (HOMA-IR value ?2.5) and IR low risk group (HOMA-IR value <2.5). Total RNA was extracted from saliva and subjected to gene expression microarray analysis using Affymetrix human genome 2.0 plus array
Project description:Saliva is a convenient non-invasive source of liquid biopsy to monitor human health and diagnose diseases. In particular, extracellular vesicles (EVs) in saliva can potentially reveal clinically relevant information for systemic health. Recent studies have shown that RNA in saliva EVs could be exploited as biomarkers for disease diagnosis. However, there is no standardized protocol for profiling RNA in saliva EV nor clear guideline on selecting saliva fractions for biomarker analysis. To address these issues, we established a robust protocol for small RNA profiling from fractionated saliva. With this method, we performed comprehensive small RNA sequencing of four saliva fractions, including cell-free saliva (CFS), EV-depleted saliva (EV-D), exosome (EXO), and microvesicle (MV) from ten healthy volunteers. Methods: To address these issues, we established a robust protocol for small RNA profiling from fractionated saliva. With this method, we performed comprehensive small RNA sequencing of four saliva fractions, including cell-free saliva (CFS), EV-depleted saliva (EV-D), exosome (EXO), and microvesicle (MV) from ten healthy volunteers.
Project description:Saliva based diagnostics is a rapidly evolving field due to the large potential of saliva and the simple sample collection. A systematic comparison of IgG antibody profiles in saliva and plasma is currently lacking in scientific literature. Our hypothesis is that IgG profiles are equal in blood and saliva. By showing the equality of the profiles and relative IgG antigenic reactivities towards proteins and peptides we provide evidence that plasma IgG reactivities can be inferred from saliva IgG reactivities. IgG antibodies were isolated from human saliva and plasma samples. The reactivities of IgG isolates were analysed on peptide microarrays displaying linear epitopes of EBV (EBNA1 protein) and HBV (Large envelope protein) virus. Peptide arrays were printed by JPT Peptide Technologies (Berlin, Germany). We show high similarity of saliva and plasma IgG profiles on these two platforms and argue for generalisation from this subset to the whole immunological IgG antibody profile.
Project description:Saliva based diagnostics is a rapidly evolving field due to the large potential of saliva and the simple sample collection. A systematic comparison of IgG antibody profiles in saliva and plasma is currently lacking in scientific literature. Our hypothesis is that IgG profiles are equal in blood and saliva. By showing the equality of the profiles and relative IgG antigenic reactivities towards proteins and peptides we provide evidence that plasma IgG reactivities can be inferred from saliva IgG reactivities. IgG antibodies were isolated from human saliva and plasma samples. The reactivities of IgG isolates were analysed on peptide microarrays displaying linear epitopes of EBV (EBNA1 protein) and HBV (Large envelope protein) virus. Peptide arrays were printed by JPT Peptide Technologies (Berlin, Germany). We show high similarity of saliva and plasma IgG profiles on these two platforms and argue for generalisation from this subset to the whole immunological IgG antibody profile.