Polymorphonuclear neutrophil integrity and functionality are preserved when exposed to saliva

ObjectivePolymorphonuclear neutrophils (PMNs) are the most abundant innate immune cells and are also important effectors in the maintenance of oral health. However, little is known about the effects of saliva on the PMN. We therefore aimed to investigate the effect of saliva on the PMNs’ morphology and functioning.DesignEffect of saliva on the membrane integrity of PMNs isolated from blood was evaluated with FACS using Annexin V (apoptosis marker) and propidum iodide (membrane integrity marker). The effect on cell morphology was examined using transmission electron imaging. Binding and phagocytosis of the oral bacterium Fusobacterium nucleatum by PMNs was analysed by FACS. Reactive oxygen species (ROS) production was measured with chemiluminescence.ResultsIncubation with saliva for 60 min had no detectable effects on the membrane integrity or the morphology of PMNs. In contrast, preincubation of F. nucleatum with saliva inhibited its subsequent interaction with PMNs, resulting in a diminished production of ROS.ConclusionsSaliva does not impair the function of PMNs. However, interaction of salivary components with F. nucleatum may affect their recognition by PMNs resulting in a diminished functional response.     

唾液外泌体在口腔鳞状细胞癌的研究进展

口腔鳞状细胞癌 (oral squamous cell carcinoma,OSCC)是影响人类健康的主要恶性肿瘤之一。由于缺少早期筛查及检测的肿瘤生物标记物,导致晚期口腔癌的致死率达到50%。外泌体(exosomes)是细胞释放到细胞外的纳米级囊泡,广泛分布于唾液中,携带生物活性分子,介导肿瘤细胞和肿瘤微环境之间的相互作用。随着对外泌体研究的深入,发现外泌体与口腔疾病的诊断和治疗有着密切的关系,可作为口腔癌早期筛查的理想标志物。本文就唾液中外泌体在口腔鳞状细胞癌的研究进展作一综述,为口腔癌早期诊断的研究提供参考。     

Deep sequencing salivary proteins for periodontitis using proteomics

Objectives

Saliva is a bodily fluid transuded from gingival crevice fluid and blood and contains many proteins. Proteins in saliva have been studied as markers for periodontal diseases. Mass spectrometric analysis is applied to investigate biomarker proteins that are related to periodontitis.

Material and methods

Saliva samples were collected from 207 participants including 36 pairs matched for age, sex, and smoking who joined Yangpyeong health cohort. Periodontitis was defined by 2005 5th European guideline. Shotgun proteomics was applied to detect proteins from saliva samples. Principal component analysis and Ingenuity Pathway Analysis for canonical pathway and protein pathway were applied. Protein-protein interaction was also applied. Enzyme-linked immunosorbent assay (ELISA) was used to verify the candidate protein markers among another matched participants (n = 80).

Results

Shotgun proteomics indicated that salivary S100A8 and S100A9 were candidate biomarkers for periodontitis. ELISA confirmed that both salivary S100A8 and S100A9 were higher in those with periodontitis compared to those without periodontitis (paired-t test, p < 0.05).

Conclusion

Our proteomics data showed that S100A8 and S100A9 in saliva could be candidate biomarkers for periodontitis. The rapid-test-kit using salivary S100A8 and S100A9 will be a practical tool for reducing the risk of periodontitis and promotion of periodontal health.

Clinical relevance

A rapid-test-kit using salivary biomarkers, S100A8 and S100A9, could be utilized by clinicians and individuals for screening periodontitis, which might reduce the morbidity of periodontitis and promote periodontal health.

     

Salivary innate defense system in type 1 diabetes mellitus in children with mixed and permanent dentition

Abstract

Objective. It should be expected that type 1 diabetes mellitus may disturb innate and acquired immunity. There are no data on type 1 diabetes mellitus-related changes in the salivary flow and the protein output responsible for the innate immunity of saliva depending on the quality of dentition reflecting the age of child. The aim of this work was the evaluation of parameters responsible for the innate immunity of saliva in children and adolescents with type 1 diabetes mellitus. Materials and methods. In diabetic children, adolescent and healthy volunteers, the salivary flow, the output and the concentration of the activity of peroxidase (colorimetry), lysozyme (radial immunodiffusion) and lactoferrin (ELISA) were determined. Results. In children with mixed and permanent dentition, type 1 diabetes mellitus significantly decreases (as compared with the appropriate controls) the unstimulated salivary flow, the output, concentration of peroxidase and the output of the lysozyme and lactoferrin. Conclusion. In conclusion, it may be stated that type 1 diabetes mellitus causes functional changes in the salivary glands, resulting in a decrease of the salivary flow and weakening of the salivary innate defense system, thus creating a threat to the oral and general health of type 1 diabetes mellitus children. The results showed that the salivary glands of younger children, when compared to adolescents with type 1 diabetes mellitus, are more susceptible to the injurious effects of the disease.     

Salivary microbiome in non-oral disease: A summary of evidence and commentary

ObjectiveThe advent of high-throughput sequencing and ‘omic’ technologies is facilitating an ‘open-ended’ understanding of the human microbial community and its interplay with health. This commentary aims to present key perspectives and summarize current evidence from metagenomic studies of salivary microbiota in relation to general health and systemic diseases.DesignA narrative review of studies that described salivary microbiome composition in relation to various general health conditions was conducted and the main results were summarized.ResultsCurrently available evidence shows salivary microbial patterns and fingerprints as related to a range of metabolic, autoimmune and immunodeficiency associated conditions, similar to albeit at a far lower scale than similar studies in the gut microbiome.ConclusionsConsidering the relative ease of collection, emerging evidence of association with non-oral diseases may imply that saliva microbiome research may have potential diagnostic or prognostic value.     

Saliva secretion in engrafted mouse bioengineered salivary glands using taste stimulation

PurposeThe aim of this study was to compare saliva flow and protein composition induced using five basic taste stimulations between natural and bioengineered salivary glands.Materials and methodsWe developed a mouse saliva secretion model using taste stimulation and analyzed the saliva secretion from natural and bioengineered salivary glands using an assay. The protein components and alpha-amylase in the natural and bioengineered saliva were analyzed by gel electrophoresis and Western blotting.ResultsThe salivary flow responses induced by sour (citric acid) and bitter (quinine-HCl) stimuli were significantly high in the natural and bioengineered salivary glands. Although the protein concentrations in the natural and bioengineered saliva induced using five basic taste stimulations were similar, the protein composition and the amylase concentration in the natural saliva after taste stimulation had different profiles. Sympathetic and non-sympathetic nerves were observed around the acini and ducts in the natural and bioengineered salivary glands. However, the frequency of neuropeptide Y-positive sympathetic nerves in the bioengineered gland was relatively high compared to that in the natural gland.ConclusionsThese results suggest that the signal balance between the sympathetic and parasympathetic components of the efferent nerves in an engrafted bioengineered salivary gland may differ from that in a natural salivary gland.     

Saliva diagnostics in patients suffering from bisphosphonate-associated osteonecrosis of the jaw: Results of an observational study

ObjectiveOne of the severe side effects of bisphosphonate (BP) therapy is bisphosphonate-associated osteonecrosis of the jaw (BONJ). However, there is no information available about its pathogenesis. Hence, the aim of this observational study was to contribute to discerning this pathogenesis by comparing salivary quantity and quality in patients with BONJ and undergoing BP treatment.Materials and methodsThis study included 60 patients divided into three groups. The first group consisted of 20 patients with established BONJ, the second group had 20 patients undergoing BP treatment, and the third group comprised 20 healthy individuals. These groups were analysed for the flow rate of stimulated saliva, buffer capacity, and salivary pH level.ResultsReduced salivation was observed in a significantly high number of patients with established BONJ (n = 8) and those undergoing BP treatment (n = 9) in comparison with the healthy control group (n = 4; p = 0.039). Though the distribution of the mean value of stimulated saliva flow rates in patients undergoing BP treatment was lower than in the control group, the difference was not significant. Moreover, there were no significant differences in the salivary pH level and buffer capacity in patients undergoing BP treatment as compared with the healthy control group.ConclusionsIt is possible that the quantity of human saliva is affected by BP treatment. This reduction in saliva production could have a negative effect on mucosal health and is perhaps a cofactor in the pathogenesis of BONJ.     

Exosomes from human saliva as a source of microRNA biomarkers

Objective:  The aim of this study was to examine the presence of microRNAs (miRNAs) within exosomes isolated from human saliva and to optimize and test methods for successful downstream applications.
Design:  Exosomes isolated from fresh and frozen glandular and whole human saliva were used as a source of miRNAs. The presence of miRNAs was validated with TaqMan quantitative PCR and miRNA microarrays.
Results:  We successfully isolated exosomes from human saliva from healthy controls and a patient with Sjögren's syndrome. microRNAs extracted from the exosomal fraction were sufficient for quantitative PCR and microarray profiling.
Conclusions:  The isolation of miRNAs from easily and non-invasively obtained salivary exosomes with subsequent characterization of the miRNA expression patterns is promising for the development of future biomarkers of the diagnosis and prognosis of various salivary gland pathologies.     

Qualitative mucin disorders in patients with primary Sjögren's syndrome: a literature review

Background It is a common opinion that Primary Sjögren Syndrome (pSS) damages the exocrine glands and determines the reduction of secreted saliva, some studies show that there are qualitative anomalies of the mucins produced in saliva, including MUC7, MUC5B, MUC1. The purpose of this study is to trace all the information useful to establish whether there is a qualitative or quantitative defect of the mucins in the pSS. Material and Methods We reviewed the literature by looking for publications relevant to the topic in electronic databases. Sixteen articles met the search criteria. The studies were divided into two categories, those that studied the rheological characteristics of the saliva and those that studied the structural and / or metabolism modifications of the muciparous cells in the salivary glands. Results in Patients with pSS, xerostomia and the reduction of salivary spinnbarkeit are only partially related to the reduction of the unstimulated salivary flow. In pSS, pathological alterations of mucins’ chemical-physical properties prevail as a cause of the clinical characteristics. Moreover, in pSS there are structural and metabolism changes in salivary glands’ muciparous cells. Conclusions There is much evidence that supports the presence of qualitative alterations in the saliva’s rheological properties in Patients with pSS, and these are the main cause, more than the reduction of the unstimulated salivary flow, of the disease clinical characteristics - dry mouth and complications in the oral cavity. Therefore we propose to add to the classification criteria of pSS also a qualitative test of salivary glycoproteins. Key words:Primary Sjögren''s syndrome, mucin, MUC7, MUC5B, MUC1, sulphate oligosaccharides.     

Saliva diagnostics: Salivaomics,saliva exosomics,and saliva liquid biopsy

BackgroundEach day, humans produce approximately 0.5 through 1.5 liters of saliva, a biofluid that is rich in biological omic constituents. Our lack of understanding how omic biomarkers migrate from diseased tissue to the saliva has impeded the clinical translation of saliva testing. Although such biomarkers must be conveyed via the vascular and lymphatic systems to the salivary glands, the molecular mechanisms that underlie this transport remain unclear. Although COVID-19 highlighted the need for rapid and reliable testing for infectious diseases, it represents only one of the many health conditions that potentially can be diagnosed using a saliva sample.Types of Studies ReviewedThe authors discuss salivaomics, saliva exosomics, and the mechanisms on which saliva diagnostics are based and introduce a novel electrochemical sensing technology that may be exploited for saliva liquid biopsy.ResultsThe utility of saliva for screening for lung cancer is under investigation. Saliva testing may be used to stratify patients, monitor treatment response, and detect disease recurrence. The authors also highlight the landscapes of saliva-based SARS-CoV-2 testing and ultrashort cell-free DNA and outline how these fields are likely to evolve in the near future.Practical ImplicationsBreakthroughs in the study of saliva research, therefore, will facilitate clinical deployment of saliva-based testing.     

Saliva and Biofilm-based Diagnostics: A Critical Review of the Literature Concerning Sialochemistry

There is some evidence to support the use of salivary diagnostics in dentistry.Background and PurposeThe use of saliva as a diagnostic fluid has the potential to shape the role of oral health care professionals in the health care system. While more than a handful of chairside diagnostic tests are available for use by private practitioners, the evidence supporting their use continues to emerge.MethodsAn electronic search of the literature indexed on the PubMed electronic database was conducted to identify human clinical trials utilizing commercially available salivary diagnostics. Papers meeting the inclusion criteria, and any applicable references were critically appraised following SORT guidelines.ConclusionsWhile the literature concerning salivary analysis is continuously growing, the limited literature that is available doesn't focus on patient oriented health outcomes. This ‘infant’ literature is focused on validating metrics and identifying biomarkers with diagnostic potential. As such, the evidence level of the literature is graded as level 3. Despite the lower grade, the research in this area shows consistent results, coherent conclusions, and research identifying new biomarkers will provide additional dimensions to salivary diagnostics.     

Hyposalivation and Xerostomia in Dentate Older Adults

BackgroundOlder adults are susceptible to reduced saliva production related to certain medications, radiation and chronic conditions. Many of these people have many physical and oral health problems and limited access to dental care. The use of effective screening tools for xerostomia and hyposalivation would be helpful in identifying those at risk. The authors conducted a study to investigate the association between three measures of oral dryness: hyposalivation (low unstimulated salivary flow), self-reported xerostomia and clinically assessed dry mouth.MethodsThe authors included a convenience sample of 252 nondemented and dentate West Virginia participants 70 years and older who were part of a larger study on oral health and cognition among older adults. Participants completed a self-reported xerostomia index, provided an unstipulated salivary sample and underwent an oral assessment for the study.ResultsTwenty-eight participants (11.1 percent) had hyposalivation, eight of whom reported having xerostomia (sensitivity = 28.6 percent). Of the 43 participants who reported having xerostomia, only eight had hyposalivation (positive predictive value = 18.6 percent). Hyposalivation and self-reported xerostomia were not significantly related. Clinically assessed dry mouth correlated modestly, but significantly, with hyposalivation and self-reported xerostomia.ConclusionsObtaining routine unstimulated salivary flow rates in addition to self-reported information and oral evaluations may increase early detection of oral dryness, which would assist in implementing early interventions to improve patients' quality of life.Clinical ImplicationsVisually inspecting oral tissues for dryness and asking a patient if his or her mouth is dry are insufficient measures for clinicians to use to determine if the patient has hyposalivation. The authors recommend that clinicians determine the patient's unstimulated salivary flow rate.     

Autonomic Nerve-Regulated AQP5 Distribution in Salivary Glands and AQP5 Release into Saliva

The salivary glands are innervated by autonomic nerves. Upon activation of M₃-muscarinic acetylcholine receptors or α₁-adrenergic receptors, cytosolic aquaporin-5 (AQP5) is translocated from intracellular endosomes to the apical plasma membrane (APM) together with lipid rafts in the parotid acinar and duct cells. Some AQP5 is dissociated from the lipid rafts to non-rafts in the APM and the dissociated AQP5 is released into the saliva from the APM. Other AQP5 associated with lipid rafts is internalized and recycled together with the lipid rafts. The subcellular distribution of AQP5 in the salivary glands and its release into the saliva are regulated by autonomic nerves. This review focuses on autonomic nerve-regulated AQP5 trafficking in the parotid glands and AQP5 release into the saliva.     

Stimulated whole salivary flow rate: The most appropriate technique for assessing salivary flow in Sjögren syndrome

Background We sought to determine the most appropriate method for measuring salivary flow to aid the diagnosis of Sjögren''s syndrome (SS). Specifically, we compared the unstimulated whole salivary flow rate (UWSFR) with the stimulated whole salivary flow rate (SWSFR).Material and Methods This case-control study comprised one group of 103 patients with SS and a control group of 50 healthy people. We measured the UWSFR and SWSFR in both groups according to the guidelines established by Navacet (1993).Results The UWSFR and SWSFR were significantly lower in the patient group compared with the controls (p < 0.01). Among the participants in the patient group, we found a decreased UWSFR in 84 individuals (81.5%) and a decreased SWSFR in 90 individuals (87.4%). We encountered difficulties obtaining saliva in 37 (35.9%) patients during the UWSFR test, and in 12 (11.7%) patients during the SWSFR test. There was no significant statistical difference in the UWSFR or SWSFR between patients with primary and secondary SS.Conclusions Compared with the UWSFR, the SWSFR is a more suiTable and effective method for measuring salivary flow in patients with SS, as well as for qualitative analysis of the obtained saliva. Key words:Sjögren syndrome, xerostomia, salivary glands.     

Oral conditions and salivary analysis in HIV-uninfected subjects using preexposure prophylaxis

Background New prevention strategies have been advocated to control the progression of HIV/AIDS, such as preexposure prophylaxis (PrEP). The aim of this study is to evaluate the potential changes in the oral and salivary conditions of HIV-uninfected subjects using PrEP.Material and Methods Subjects were evaluated before beginning the medication (T0), at the first follow-up (T1), and at the second follow-up (T2). Xerostomia, presence of untreated cavitated caries, oral hygiene habits, taste, gingival and plaque index, stimulated salivary flow rate (SSFR), and salivary concentrations of calcium, glucose, urea, and total proteins were evaluated. Data obtained were analyzed using statistical tests (p<0.05).Results Forty-seven participants (41 men; 6 women) were evaluated at T0. Thirty (28 men; 2 women) and 17 men were reassessed at T1 and T2, respectively. There was no difference between the SSFR and oral and salivary conditions between T0, T1, and T2 (p>0.05), except for the salivary calcium concentration, that increased at T2 compared to T1 (p=0.02). There was significant difference between taste and xerostomia at T1 (p=0.017), and the need to drink to swallow at T2 (p=0.015). There was significant correlation between the reported amount of saliva and taste (p=0.039, r=-0.378) at T1.Conclusions The prolonged use of PrEP seems to be associated with reports of dry mouth and worsening of taste, possibly associated with increased salivary calcium concentration. Key words:Antiretroviral agents, pre-exposure prophylaxis, saliva, oral health.     

Effects of hyperleptinemia in rat saliva composition,histology and ultrastructure of the major salivary glands

ObjectiveTo study the effect of the satiety hormone, leptin, in saliva proteome and salivary gland histology and ultrastructure.DesignIncreases in blood leptin levels were induced through mini-pump infusion in male Wistar rats, during a period of 7 days. Saliva was collected before and at the end of the experimental period, for proteomic analysis, and major salivary glands were collected, at the end, for biochemical, histological and ultrastructural analysis.ResultsImmunohistochemistry revealed the presence of leptin receptors in major salivary glands. Salivary amylase levels and enzymatic activity were decreased in saliva, whereas the enzymatic activity of this protein was increased in the cytosol of parotid gland cells. Transmission electron microscopy allowed the observation of high number of electron-dense granules in cytosol of parotid acinar cells, from leptin treated animals.ConclusionsIncreased levels of plasmatic leptin result in changes in saliva composition and salivary glands function. To our knowledge, this is the first study providing evidences for a potential role of leptin in salivary gland secretion and saliva composition. An understanding of how appetite/satiety factors influence saliva composition and how this composition influences food processing in mouth may be relevant in understanding ingestivebehaviour.     

Salivary concentration of the antimicrobial peptide LL-37 in children

ObjectiveAntimicrobial peptides are important components of innate immunity, especially in the unique environment of the oral cavity. Lack of the human cathelicidin LL-37 has been implicated in severe periodontitis, whilst high salivary levels of LL-37 seem to increase caries resistance. Limited data exists about the concentration of LL-37 in saliva of young children. In this study, the salivary concentration of LL-37 was examined in relation to age, gender, type of dentition (primary, mixed or permanent) and caries experience of children.DesignUnstimulated whole saliva was collected from 49 systemically healthy and gingivitis free children aged 2–18 years old. Their caries activity was recorded. The salivary LL-37 concentration was determined by enzyme linked immunosorbent assay (ELISA).ResultsLL-37 was detected in all saliva samples. Its concentration varied widely, with girls exhibiting higher peptide levels than boys. A positive correlation of the LL-37 concentration was observed with age. Children with primary dentition had significantly lower peptide concentration than those with mixed or permanent dentition. Significantly lower concentrations of LL-37 were also found in children with high caries activity, compared to caries free children or to children with low to moderate caries activity.ConclusionsOur results reinforce the belief that LL-37 is an important molecule of immunity in the oral environment and it seems to play a protective role against caries.     

Oral shedding of HSV-1 and EBV and oral manifestations in paediatric chronic kidney disease patients and renal transplant recipients

Objective: Previous research demonstrated that salivary shedding of HSV-1 and EBV occurs often in adult renal transplant recipients, but there is a lack of studies on the presence of them in the saliva of paediatric population. Therefore, the objective of this study is to describe oral characteristics and to compare the shedding profile of HSV-1 and EBV in the saliva of children with renal transplant to that of chronic kidney disease patients and controls.

Methods: This is a cross-sectional study involving 100 children, being 25 renal transplant recipients, 25 chronic kidney disease patients and 50 healthy children. Demographic and oral clinical characteristics were assessed. Saliva samples were collected and submitted to screening for EBV and HSV-1 by using nested polymerase chain reaction technique. Fisher’s exact, Pearson’s chi-square and Kruskal–Wallis tests were used for statistical analysis at a significance level of 5%.

Results: Oral shedding of HSV-1 (28%) and EBV (60%) were significantly higher in renal transplant recipients compared to the other groups. Single vesicles in the oral mucosa were statistically associated with the presence of HSV-1 (p?=?.035). In children with chronic kidney disease, there was a higher prevalence of pale oral mucosa (32%) and enamel hypoplasia (40%) compared to paediatric renal transplant recipients and controls. Dental calculus (36%), candidiasis (8%), drug-induced gingival overgrowth (16%), mouth blisters (8%), xerostomia (12%) and salivary gland enlargement (20%) were more common in paediatric renal transplant recipients.

Conclusions: Therefore, it can be concluded that salivary shedding of HSV-1 and EBV in paediatric patients was more often found in renal transplant recipients than in the renal failure and control children. Transplanted recipients showed more oral manifestations than renal failure and control children did.