Salivary changes in oral mucosal diseases

Clinical Applications for Dentistry and Oral Health

In the last few years, dentistry has expanded the scope of its research and increased its cooperation with other disciplines [...]

Salivary flow rates and buffer capacity and its relationship with oral health status: a cross-sectional study on crack-cocaine-addicted males

This cross-sectional study evaluated the saliva profile in crack-cocaine-addicted males and its relationship with dental caries, periodontal disease, and oral mucosal lesion (OML) using 148 adult male volunteers (37 addicted; 111 non-addicted) at the School of Dentistry, Federal University of Bahia. Data on decayed, missing and filled teeth (DMFT), periodontal disease and OML were collected from the clinical examination of the participants. Samples were analysed for the salivary flow rate (SFR) of unstimulated and wax-stimulated whole saliva and the saliva buffer capacity. Bivariate and regression analyses were conducted to assess the salivary profile and its association with the oral status of addicted participants (α = 0.05). The mean buffer capacity of stimulated saliva was significantly lower in the addicted participants (pH 5.2 ± 1.7) than in the non-addicted group (pH 5.8 ± 1.3, p = 0.03). In the addicted group, OML was associated with a stimulated SFR < 1.0 mL/min (OR = 11.98, 95% CI = 1.30-27.10, p = 0.04). The DMFT index and periodontal disease were not associated with the salivary profile, but with older age (OR = 7.20, 95% CI = 1.51-31.14, p = 0.01) and lower education levels (OR = 24.00, 95% CI = 1.68-341.00, p = 0.02), respectively. In conclusion, addiction was associated with the lower buffer capacity of stimulated saliva, and OML was associated with lower-stimulated salivary flow rate. Periodontal disease or DMFT was not associated with salivary factors in addicted males. Therapy approaches dealing with saliva status may be important for use with addicted males to reduce OMLs.

The Association Between Some Macro and Trace Elements in Saliva and Periodontal Status

Changes in the macro and trace element composition of saliva might be indicative for pathological changes in periodontal tissues. However, there is a lack of evidence in the literature showing associations between mineral elements and periodontal status. The aim of this study was to determine whether such associations occur. Totally, 190 systemically healthy non-smoker participants (mean age 32.2 ± 6.02; 50 periodontally healthy, 50 gingivitis, 50 chronic periodontitis, and 40 aggressive periodontitis individuals) were included in this cross-sectional study. Salivary levels of some macro and trace elements were measured by using inductively coupled plasma mass spectrometry (ICP-MS). Kruskal-Wallis's test was used for statistical analysis. Statistically significant differences were found in sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), vanadium (V), chromium Cr), manganese (Mn), iron (Fe), rubidium (Rb), strontium (Sr), and selenium (Se) concentrations among the groups. Significant increases in the essential minerals Na, Mg, K, Ca, Fe, and Se occurred in both periodontitis groups when compared to the gingivitis and periodontally healthy groups. Lower Se, Sr, Fe, Mn, and V concentrations were found in the aggressive periodontitis group than in the chronic periodontitis group. The results of this study demonstrated that assessment of mineral element concentrations in saliva might be useful in assessing periodontal health and disease. However, further studies are required to determine whether the change in a specific mineral element is the result of periodontal disease or is involved in its pathogenesis.

Exosomes from EV71-infected oral epithelial cells can transfer miR-30a to promote EV71 infection

OBJECTIVE

As an extracellular vesicle, exosomes can release from virus-infected cells containing various viral or host cellular elements and could stimulate recipient's cellular response. Enterovirus 71 (EV71), a single-strand positive-sense RNA virus, is known to cause hand, foot, and mouth disease (HFMD) in children and bring about severe clinical diseases.

METHODS

Separated the human oral epithelial cells (OE cells) from normal buccal mucosa through enzyme digestion. Performed a comprehensive miRNA profiling in exosomes from EV71-infected OE cells through deep small RNA-seq. Using the Human Antiviral Response RT Profiler PCR Array profiles to explore the interactions of innate immune signaling networks with exosomal miR-30a. Knocked out the MyD88 gene in macrophages using CRISPR/Cas9-mediated genome editing method.

RESULTS

Our study demonstrated that the miR-30a was preferentially enriched in exosomes that released from EV71-infected human oral epithelial cells through small RNA-seq. We found that the transfer of exosomal miR-30a to macrophages could suppress type Ⅰ interferon response through targeting myeloid differentiation factor 88 (MyD88) and subsequently facilitate the viral replication.

CONCLUSIONS

Exosomes released from EV71-infected OE cells selectively packaged high level of miR-30a that can be functionally transferred to the recipient macrophages resulted in targeting MyD88 and subsequently inhibited type I interferon production in receipt cells, thus promoting the EV71 replication.

Salivary Biomarkers for Alzheimer's Disease and Related Disorders

The search for accessible and cost-effective biomarkers to complement current cerebrospinal fluid (CSF) and imaging biomarkers in the accurate detection of Alzheimer disease (AD) and other common neurodegenerative disorders remains a challenging task. The advances in ultra-sensitive detection methods has highlighted blood biomarkers (e.g. amyloid-β and neurofilament light) as a valuable and realistic tool in a diagnostic or screening process. Saliva, however, is also a rich source of potential biomarkers for disease detection and offers several practical advantages over biofluids that are currently examined for neurodegenerative disorders. However, while this may be true for the general population, challenges in collecting saliva from an elderly population should be seriously considered. In this review, we begin by discussing how saliva is produced and how age-related conditions can modify saliva production and composition. We then focus on the data available which support the concept of salivary amyloid-β, tau species and novel biomarkers in detecting AD and alpha-synuclein (α-syn) in Parkinson's disease (PD).

Protein-Based Salivary Profiles as Novel Biomarkers for Oral Diseases

The Global Burden of Oral Diseases affects 3.5 billion people worldwide, representing the number of people affected by the burden of untreated dental caries, severe periodontal disease, and edentulism. Thus, much more efforts in terms of diagnostics and treatments must be provided in the fight of these outcomes. In this sense, recently, the study of saliva as biological matrix has been identified as a new landmark initiative in the search of novel and useful biomarkers to prevent and diagnose these conditions. Specifically, saliva is a rich reservoir of different proteins and peptides and accessible due to recent advances in molecular biology and specially in targeted and unbiased proteomics technologies. Nonetheless, emerging barriers are an obstacle to the study of the salivary proteome in an effective way. This review aims at giving an overall perspective of salivary biomarkers identified in several oral diseases by means of molecular biology approaches.

Antioxidant capacity and biomarkers of oxidative stress in saliva of khat-chewing patients: a case-control study

OBJECTIVES

The aim of this study was to investigate the antioxidant levels and biomarkers of oxidative stress in saliva from khat-chewing patients compared with controls.

STUDY DESIGN

Saliva samples were collected from 51 chronic khat chewers and 46 age- and sex-matched controls. Concentrations of oxidative stress biomarkers (malonyl-dialdehyde [MDA], protein carbonyl, and 8-hydroxy-2'-deoxyguanosine) and antioxidant defense (total antioxidant capacity [TAC], superoxide dismutase, glutathione peroxidase, and catalase [CAT) were analyzed.

RESULTS

Salivary MDA level in the khat users group (45 ± 9.2 nmol/mL) was significantly increased in comparison with controls (13 ± 2.1 nmol/mL; P < .001), but there were no significant differences between the 2 groups regarding the levels of salivary protein carbonyl and oxidized guanine species. Salivary TAC was significantly reduced in khat users (0.25 ± 0.028 mmol/L) in comparison with controls (0.34 ± 0.037 mmol/L). Salivary CAT level was significantly reduced in khat users (6.0 ± 0.47 U/mL) in comparison with controls (7.7 ± 0.43 units/mL; P <.05), but no significant differences were observed between the 2 groups with regard to salivary superoxide dismutase or glutathione peroxidase levels.

CONCLUSIONS

Chronic khat chewing is associated with increased levels of salivary MDA and reduced levels of TAC and CAT among a population of adult men in comparison with non-khat-chewing controls. These findings suggest that the pro-oxidative effect of khat chewing may be a contributing mechanism for various oral diseases associated with khat use, including cancer, periodontitis, and caries.

Salivary Markers for Periodontal and General Diseases

The determination of biomarkers in saliva is becoming an important part of laboratory diagnostics and the prediction of not only periodontal, but also other tissue and organ diseases. Biomarkers in saliva (e.g., enzymes, protein markers, or oxidative stress markers) can be used for activity determination and for periodontal disease prognosis. Saliva also contains many markers which can predict the risk of certain diseases (e.g., diabetes mellitus, cardiovascular, oncology, endocrinology, and psychiatric diseases). The study of salivary components proteomics clearly shows the relationship of periodontal diseases and diseases of distant systems, organs, or tissues.