Salivary inflammatory cytokines may be novel markers of carotid atherosclerosis in a Japanese general population: the Suita study

Identification of N-linked glycans recognized by WGA in saliva from patients with non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer-related deaths. Saliva diagnosis is an essential approach for clinical applications owing to its noninvasive and material-rich features. The purpose of this study was to investigate differences in wheat germ agglutinin (WGA)-based recognition of salivary protein N-linked glycan profiles to distinguish non-small cell lung cancer (NSCLC) patients from controls. We used WGA-magnetic particle conjugates to isolate glycoproteins in the pooled saliva of healthy volunteers (HV, n = 35), patients with benign pulmonary disease (BPD, n = 35), lung adenocarcinoma (ADC, n = 35), and squamous cell carcinoma (SCC, n = 35), following to release the N-linked glycans from the isolated proteins with PNGase F, and further identified and annotated the released glycans by MALDI-TOF/TOF-MS, respectively. The results showed that 34, 35, 39, and 44 N-glycans recognized by WGA were identified and annotated from pooled saliva samples of HV, BPD, ADC, and SCC, respectively. Furthermore, the proportion of N-glycans recognized by WGA in BPD (81.2 %), ADC (90.1 %), and SCC (88.7 %), increased compared to HV (71.9 %). Two N-glycan peaks (m/z 2286.799, and 3399.211) specifically recognized by WGA were present only in NSCLC. These findings suggest that altered salivary glycopatterns such as sialic acids and GlcNAc containing N-glycans recognized by WGA might serve as potential personalized biomarkers for the diagnosis of NSCLC patients.

Salivary cardiac-enriched FHL2-interacting protein is associated with higher diastolic-to-systolic-blood pressure ratio, sedentary time and center of pressure displacement in healthy 7-9 years old school-children

Introduction

Cardiac-enriched FHL2-interacting protein (CEFIP) is a recently identified protein, first found in the z-disc of striated muscles, and related to cardiovascular diseases. Our objectives are: 1) to quantify CEFIP in saliva in healthy 7-9 years old school-children; and 2) to assess the associations of salivary CEFIP concentration and blood pressure, physical (in)activity and physical fitness in these children.

Methods

A total of 72 children (7.6 ± 0.3 years) were included in the study, recruited in primary schools in Girona (Spain). A sandwich enzyme-linked immunosorbent assay was used (abx506878; Abbexa, United Kingdom) to quantify CEFIP in saliva. Anthropometric evaluation was performed [body mass, height and body mass index (BMI)]. Systolic and diastolic blood pressure were measured by means of an electronic oscillometer and the diastolic-to-systolic blood pressure ratio (D/S BP ratio) was calculated. Physical (in)activity [sedentary time and time spent in physical activity (PA)] were assessed by means of a triaxial Actigraph GT3X accelerometer (Actigraph, Pensacola, FL, USA) that children were instructed to wear for 24h during 7 conssecutive days. Finally, physical fitness (speed and agility, explosive power of legs, handgrip strength, flexibility and balance) were assessed through validated and standardized testing batteries.

Results

CEFIP was easily detected and measured in all saliva samples (mean concentration: 0.6 ± 0.2 pg/ml). Salivary CEFIP was positively associated with D/S BP ratio (r=0.305, p=0.010) and sedentary time (r=0.317, p=0.012), but negatively associated with PA in 7-9 years old school-children (r=-0.350, p=0.002). Furthermore, salivary CEFIP was related to lower level of balance i.e., higher center of pressure (CoP) displacement in these children (r=0.411, p<0.001). The associations of salivary CEFIP with D/S BP ratio (Beta=0.349, p=0.004), sedentary time (Beta=0.354, p=0.009) and CoP displacement (Beta=0.401, p=0.001), were maintained significant after adjustment for potential confounding variables such as age, gender and BMI in linear regression analyses.

Conclusion

CEFIP can be easily assessed in saliva as a promising biomarker associated with cardiovascular health in 7-9 years old school-children. Interestingly, higher salivary CEFIP concentration was related to higher D/S BP ratio, more sedentary time and higher CoP displacement i.e., lower level of balance in these children.

Biomarkers of Cardiovascular Diseases in Saliva and Gingival Crevicular Fluid: A Review

Due to the fact that cardiovascular diseases (CVDs) have become the most serious problem in public health, there is a need for new and efficient methods for screening and early detection. In the recent literature, saliva and gingival crevicular fluid (GCF) have been gaining recognition as sources of many potential biomarkers of various systemic diseases, mainly because of correlation between the level of some compounds in the blood and saliva and association between the composition of saliva and health status. In this review, we summarize published findings of patients with atherosclerosis, arterial hypertension, coronary artery disease (CAD), acute coronary syndrome (ACS), and stroke in the context of clinical utility of saliva and GCF in diagnosing and assessing CVD severity. We hypothesize that substances in saliva including inflammatory markers, enzymes, or hormones might become novel contributors to the diagnosis and screening of CVDs. In particular, C-reactive protein (CRP), tumor necrosis alpha (TNFα), and cortisol seem to be the most promising. However, further investigation is warranted to determine the most effective markers and methods for their analysis.

Protein-based salivary biomarkers for the diagnosis of periodontal diseases: Systematic review and meta-analysis

Objective

This systematic review and meta-analysis was aimed at determining differentially expressed protein-based biomarkers detectable in the saliva for the diagnosis of major periodontal diseases.

Methods

A literature review was conducted through January 31, 2022. The methodological quality and risk of bias were assessed with the Newcastle-Ottawa scale for case-control studies. Heterogeneity among studies was analysed with the Q statistical test and the I2 test. p-values lower than 0.10 and I2 values higher than 50% indicated high heterogeneity among studies; therefore, the random-effects model was used. The analysis of biological pathways associated with the differentially expressed protein markers was performed with the STITCH integration analysis tool and was limited to interactions with high confidence levels (0.7).

Results

Of all protein-based biomarkers detected, 12 were suitable for meta-analysis: IL-1β, MIP-1α, albumin, TNF-α, ICTP, Ig-A, lactoferrin, MMP-8, IL-6, IL-8, IL-17 and PGE2. The salivary markers with high applicability were IL-1β for differentiating patients with chronic periodontal disease from patients with gingivitis with an OE = 73.5 pg/mL; ICTP for differentiating patients with chronic periodontal disease from healthy control patients with an OE = 0.091 ng/mL; and PGE2 for differentiating patients with chronic periodontal disease from healthy control patients with an OE = 36.3 pg/mL.

Conclusions

The biomarkers with the highest differential expression and the greatest potential for clinical applicability are IL-1β for differentiating periodontitis from gingivitis, and ICTP and PGE2 for differentiating periodontitis from healthy status.

Salivary biomarkers: novel noninvasive tools to diagnose chronic inflammation

Several chronic disorders including type 2 diabetes (T2D), obesity, heart disease and cancer are preceded by a state of chronic low-grade inflammation. Biomarkers for the early assessment of chronic disorders encompass acute phase proteins (APP), cytokines and chemokines, pro-inflammatory enzymes, lipids and oxidative stress mediators. These substances enter saliva through the blood flow and, in some cases, there is a close relation between their salivary and serum concentration. Saliva can be easily collected and stored with non-invasive and cost-saving procedures, and it is emerging the concept to use it for the detection of inflammatory biomarkers. To this purpose, the present review aims to discuss the advantages and challenges of using standard and cutting-edge techniques to discover salivary biomarkers which may be used in diagnosis/therapy of several chronic diseases with inflammatory consequences with the pursuit to possibly replace conventional paths with detectable soluble mediators in saliva. Specifically, the review describes the procedures used for saliva collection, the standard approaches for the measurement of salivary biomarkers and the novel methodological strategies such as biosensors to improve the quality of care for chronically affected patients.

A Review on Saliva-Based Health Diagnostics: Biomarker Selection and Future Directions

The human body has a unique way of saying when something is wrong with it. The molecules in the body fluids can be helpful in the early detection of diseases by enabling health and preventing disease progression. These biomarkers enabling better healthcare are becoming an extensive area of research interest. Biosensors that detect these biomarkers are becoming the future, especially Point Of Care (POC) biosensors that remove the need to be physically present in the hospital. Detection of complex and systemic diseases using biosensors has a long way to go. Saliva-based biosensors are gaining attention among body fluids due to their non-invasive collection and ability to detect periodontal disease and identify systemic diseases. The possibility of saliva-based diagnostic biosensors has gained much publicity, with companies sending home kits for ancestry prediction. Saliva-based testing for covid 19 has revealed effective clinical use and relevance of the economic collection. Based on universal biomarkers, the detection of systemic diseases is a booming research arena. Lots of research on saliva-based biosensors is available, but it still poses challenges and limitations as POC devices. This review paper talks about the relevance of saliva and its usefulness as a biosensor. Also, it has recommendations that need to be considered to enable it as a possible diagnostic tool.

Graphical Abstract

Changes in the salivary metabolome in patients with chronic erosive gastritis

INTRODUCTION

Chronic erosive gastritis (CEG) is closely related to gastric cancer, which requires early diagnosis and intervention. The invasiveness and discomfort of electronic gastroscope have limited its application in the large-scale screening of CEG. Therefore, a simple and noninvasive screening method is needed in the clinic.

OBJECTIVES

The aim of this study is to screen potential biomarkers that can identify diseases from the saliva samples of CEG patients using metabolomics.

METHODS

Saliva samples from 64 CEG patients and 30 healthy volunteers were collected, and metabolomic analysis was performed using UHPLC-Q-TOF/MS in the positive and negative ion modes. Statistical analysis was performed using both univariate (Student's t-test) and multivariate (orthogonal partial least squares discriminant analysis) tests. Receiver operating characteristic (ROC) analysis was conducted to determine significant predictors in the saliva of CEG patients.

RESULTS

By comparing the saliva samples from CEG patients and healthy volunteers, 45 differentially expressed metabolites were identified, of which 37 were up-regulated and 8 were down-regulated. These differential metabolites were related to amino acid, lipid, phenylalanine metabolism, protein digestion and absorption, and mTOR signaling pathway. In the ROC analysis, the AUC values of 7 metabolites were greater than 0.8, among which the AUC values of 1,2-dioleoyl-sn-glycoro-3-phosphodylcholine and 1-stearoyl-2-oleoyl-sn-glycoro-3-phospholine (SOPC) were greater than 0.9.

CONCLUSIONS

In summary, a total of 45 metabolites were identified in the saliva of CEG patients. Among them, 1,2-dioleoyl-sn-glycoro-3-phosphorylcholine and 1-stearoyl-2-oleoyl-sn-glycoro-3-phosphorine (SOPC) might have potential clinical application value.

Updates and Original Case Studies Focused on the NMR-Linked Metabolomics Analysis of Human Oral Fluids Part III: Implementations for the Diagnosis of Non-Cancerous Disorders, Both Oral and Systemic

This communication represents Part III of our series of reports based on the applications of human saliva as a useful and conveniently collectable medium for the discovery, identification and monitoring of biomarkers, which are of some merit for the diagnosis of human diseases. Such biomarkers, or others reflecting the dysfunction of specific disease-associated metabolic pathways, may also be employed for the prognostic pathological tracking of these diseases. Part I of this series set the experimental and logistical groundwork for this report, and the preceding paper, Part II, featured the applications of newly developed metabolomics technologies to the diagnosis and severity grading of human cancer conditions, both oral and systemic. Clearly, there are many benefits, both scientific and economic, associated with the donation of human saliva samples (usually as whole mouth saliva) from humans consenting to and participating in investigations focused on the discovery of biomolecular markers of diseases. These include usually non-invasive collection protocols, relatively low cost when compared against blood sample collection, and no requirement for clinical supervision during collection episodes. This paper is centred on the employment and value of 'state-of-the-art' metabolomics technologies to the diagnosis and prognosis of a wide range of non-cancerous human diseases. Firstly, these include common oral diseases such as periodontal diseases (from type 1 (gingivitis) to type 4 (advanced periodontitis)), and dental caries. Secondly, a wide range of extra-oral (systemic) conditions are covered, most notably diabetes types 1 and 2, cardiovascular and neurological diseases, and Sjögren's syndrome, along with a series of viral infections, e.g., pharyngitis, influenza, HIV and COVID-19. Since the authors' major research interests lie in the area of the principles and applications of NMR-linked metabolomics techniques, many, but not all, of the studies reviewed were conducted using these technologies, with special attention being given to recommended protocols for their operation and management, for example, satisfactory experimental model designs; sample collection and laboratory processing techniques; the selection of sample-specific NMR pulse sequences for saliva analysis; and strategies available for the confirmation of resonance assignments for both endogenous and exogenous molecules in this biofluid. This article also features an original case study, which is focussed on the use of NMR-based salivary metabolomics techniques to provide some key biomarkers for the diagnosis of pharyngitis, and an example of how to 'police' such studies and to recognise participants who perceive that they actually have this disorder but do not from their metabolic profiles and multivariate analysis pattern-based clusterings. The biochemical and clinical significance of these multidimensional metabolomics investigations are discussed in detail.

Validity of a combination of periodontal pathogens and salivary biomarkers as predictors of periodontitis

OBJECTIVE

Chronic periodontitis is caused by multiple risk factors. To predict chronic periodontitis in older people, we evaluated the association between a combination of major periodontal pathogens and salivary biomarkers and the presence of periodontitis.

METHODS

Stimulated saliva samples were collected to analyze the prevalence of Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Prevotella intermedia, as well as four biomarkers: interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2). A total of 201 Japanese patients were recruited. Oral examinations ware performed to determine chronic periodontitis as measured by Community Periodontal Index. The sociodemographic and behavioral characteristics were also obtained, and the parameters were adjusted as potential confounders to employ statistical models.

RESULTS

The odds ratio (OR) for the presence of P. gingivalis and the third tertile level of IL-1β as compared with the absence of P. gingivalis and the lowest tertile of IL-1β was highest in individuals with periodontitis (OR = 13.98; 95% confidence interval [CI] 3.87-50.52) with the best level (0.79) of area under the curve (AUC) based on the receiver operating characteristic curve. The OR for the presence of P. gingivalis and the third tertile of PGE2 was 7.76 (CI 1.89-31.91) with an AUC of 0.78. The coexistence of more than two periodontal bacteria and the third tertile of PGE2 was also strongly associated with chronic periodontitis (OR = 9.23, 95% CI 2.38-35.79) with an AUC of 0.76.

CONCLUSIONS

The combined information of the presence of P. gingivalis in stimulated saliva, and higher levels of salivary IL-1β may play a vital role in the detection and prediction of chronic periodontitis in older adults.

Heart Rate Variability and Inflammatory Stress Response in Young African American Men: Implications for Cardiovascular Risk

Background: African American men have a disproportionately higher incidence of and suffer greater severity and earlier death from cardiovascular disease (CVD). A common feature of many diseases, which disproportionately afflict disadvantaged African Americans, is inflammation. In particular, inflammation plays a decisive role in the pathogenesis of CVD in that persistent inflammation contributes to plaque evolution and destabilization. Adverse childhood experiences increase the risk for adult inflammatory based disease, particularly cardiovascular disease. This inflammatory burden becomes evident during stressful events and may be related to alterations in autonomic nervous system (ANS) activity. We previously reported that African American men who experienced childhood adversity exhibited a greater inflammatory (IL-6) response to acute stress challenge (Trier Social Stress Test - TSST). The purpose of this study was to determine whether altered ANS activity, as measured by heart rate variability (HRV), contributes to a greater proinflammatory response to stress in those exposed to childhood adversity. Methods: Thirty-four African American adult males underwent the TSST while instrumented with Holter monitors to record continuous heart rate for HRV determination. HRV was calculated as the low frequency (LF) to high frequency (HF) heart rate ratio (LF/HF), with higher LF/HF ratios corresponding to higher sympathetic vs. parasympathetic activity. Salivary samples were collected pre- and post-TSST to measure the proinflammatory cytokine IL-6. Childhood adversity was assessed by the Childhood Trauma Questionnaire. Results: Hierarchical linear modeling demonstrated that higher levels of physical abuse were related to a steeper rise in LF/HF ratio during the TSST. Further, a higher LF/HF ratio, in combination with greater exposure to emotional and physical abuse was associated with a greater IL-6 response to the TSST. Conclusions: These findings suggest that adverse childhood experiences associate with an adult phenotype characterized by an altered ANS response to stress as well as a greater proinflammatory (IL-6) response to an acute stressor. Elevations in salivary inflammatory markers have been associated with increased CVD risk. In conclusion, these findings suggest a role for the ANS in the underlying neuro-biological processes whereby childhood adversity predisposes to a more intense inflammatory response to stressful challenge during adulthood.

Investigation of the relationship between periodontal and systemic inflammation in children with Sickle Cell Disease: A case- control study

Periodontal diseases are chronic inflammatory diseases and tissue destruction increases with oxidative stress in periodontal tissues. Periodontal diseases are associated with systemic diseases such as diabetes, cardio-vascular diseases and rheumatoid arthritis by means of systemic inflammation. Sickle cell disease (SCD) is a chronic inflammatory disease in which vaso-occlusive crisis and endothelial dysfunction are present. It is not known whether the chronic systemic inflammation seen in SCD affect periodontal tissues. The aim of this study was to investigate the relationship between periodontal and systemic inflammation in children with SCD. Forty-three children with SCD and 43 healthy children were included in the study. Physical, dental and periodontal statuses were examined, blood and saliva samples were taken. Levels of pro-inflammatory and oxidative stress mediators in serum and saliva were evaluated. The periodontal findings of the groups were similar. The majority of the subjects in both groups had gingival inflammation. In SCD group, significantly higher serum high sensitive C-reactive protein (Hs-CRP), interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, total oxidant status (TOS), nitric oxide (NO) and salivary IL-6 were observed (p < 0.05). There were positive correlations between salivary IL-6 levels and serum Hs-CRP levels (r = 0.303, p < 0.05). In addition; it was determined that salivary IL-6, TNF-α and NO levels were increased 3-6 times in children with a history of painful crisis or acute chest syndrome compared to children who had never had a painful crisis or acute chest syndrome. Although, observed oral health status was similar in both groups, salivary cytokine levels were increased in children with SCD. The higher salivary cytokine levels may be associated with chronic systemic inflammation and vaso-occlusion observed in children with SCD.

The levels of soluble urokinase plasminogen activator receptor (suPAR) in saliva are influenced by acute stress

Although elevations in systemic suPAR levels have been associated with inflammatory conditions and with exposure to life stress and adversity, it is not yet clear whether acute psychological stress influences suPAR levels, either systemically and/or in saliva. The aim of this study was to investigate whether salivary suPAR levels are increased following exposure to acute psychological stress. Healthy subjects, aged 18-40 years, completed a laboratory psychological stressor and provided saliva samples before and after the stress test (60 min apart). Levels of suPAR as well as those of cytokines increased in the post-stress samples (all ps < .001). Baseline and post-stress IL-1β and TNF-α as well as post-stress IL-6 correlated significantly with suPAR (all ps < .01), but IL-10 and baseline IL-6 did not. These results show that suPAR levels in saliva are stress-reactive and suggest a potential application as stress biomarkers in saliva, particularly given the advantage of easily detectable concentrations.

Saliva as a Source of Biomarkers for Periodontitis and Periimplantitis

Saliva has the potential to be used as a diagnostic and monitoring tool for various diseases if biomarkers of an adequate sensitivity and specificity could be identified. Several reviews and even meta-analyses have been performed in recent years, which have found some candidate biomarkers for periodontitis, like macrophage inflammatory protein-1 alpha, interleukin-1ß, interleukin-6, matrix metalloproteinase-8, or hemoglobin. However, none of those are currently in use to replace conventional periodontal diagnostics with a periodontal probe. For periimplantitis, to date, heterogeneity of different study protocols and implant types did not permit to discover clear biomarkers, which were able to distinguish between healthy and diseased implants. Few proinflammatory cytokines, similar to periodontitis, have been characterized as adjunct tools to clinical diagnosis. The additional determination of antimicrobial peptides, bone turnover markers, and bacteria could help to enhance sensitivity and specificity in a combined model for periodontitis and periimplantitis. Furthermore, proteomic approaches might be preferred over single biomarker determinations. A global consensus is also needed to harmonize salivary sampling methods as well as procedures of biomarker analysis to ensure future comparability.

Identification of the different salivary Interleukin-6 profiles in patients with periodontitis: A cross-sectional study

OBJECTIVE

The aim of this study was to analyze and identify the association among salivary interleukin-6 (IL-6) levels and periodontitis (PT) and to determine the significant trend of this association in PT patients.

STUDY DESIGN

For the present study, 49 patients with PT and 47 healthy subjects (HS) were enrolled and assessed for clinical parameters, blood samples and salivary IL-6 analyses. Clinical differences among groups were recorded and evaluated. The Spearman Correlation and the Jonckheere-Terpstra Test were applied in order to assess the interdependence between salivary IL-6 and PT.

RESULTS

Patients in the PT group had significantly higher median salivary IL-6 levels [195.4 (184.6-205.9 pg/mL)] compared to the HS group [101.9 (89.5-115.4 pg/mL) (p < 0.001). Salivary IL-6 levels were negatively correlated with C-reactive protein, with the number of teeth and with clinical attachment loss (CAL), probing pocket depth (PPD), and bleeding sites (FMBS) (p < 0.001). Furthermore, in patients with PT, salivary IL-6 levels were inversely associated (P-trend) with the number of teeth (p < 0.001), and directly associated with the proportional extent of PT (CAL, p = 0.006; PPD, p = 0.009; FMBS, p < 0.001).

CONCLUSIONS

The results of this study showed that PT patients presented significant higher salivary IL-6 levels compared to HS. Moreover, in the analyzed sample a significant p-trend among PT, tooth loss and increased salivary IL-6 levels was found.

The Challenges of OSCC Diagnosis: Salivary Cytokines as Potential Biomarkers

Fast, economic, and noninvasive, molecular analysis of saliva has the potential to become a diagnostic tool of reference for several local and systemic diseases, oral cancer included. The diagnosis of Oral Squamous Cell Carcinoma (OSCC) can be performed using high specificity and sensibility biomarkers that can be encountered in the biological fluids. Recent advances in salivary proteomics have underlined the potential use of salivary biomarkers as early diagnosis screening tools for oral neoplasia. In this respect, over 100 salivary molecules have been described and proposed as oral cancer biomarkers, out of which cytokines are among the most promising. Besides being directly involved in inflammation and immune response, the role of salivary cytokines in tumor growth and progression linked them to the incidence of oral malignant lesions. This review summarizes the existing studies based on the use of salivary cytokines as potential oral cancer biomarkers, their involvement in the malignant process based on their type, and ther influence upon prognostic and metastatic rates.

A Review of Salivary Diagnostics and Its Potential Implication in Detection of Covid-19

Saliva is an exocrine secretion produced from the salivary glands and has numerous functions, such as cleansing and protection of the oral cavity, antimicrobial effects and aids in digestion. Due to the speedy development in the field of salivaomics, saliva is now well accepted as a pool of biological markers that vary from changes in biochemicals, nucleic acids and proteins to the microflora. Saliva has an immense potential as a diagnostic fluid and offers an edge over other biological fluids as its collection method does not require invasive procedure, economical and is useful for monitoring systemic health. Development of sensitive and precise salivary diagnostic tools and the formulation of defined guidelines following meticulous testing will allow salivary diagnostics to be utilised as chair side tests for various oral and systemic diseases in the near future. The coronavirus disease (Covid-19) pandemic is the biggest challenge and global health crisis for the world since World War Two. Rapid and accurate diagnosis of Covid-19 is crucial in controlling the outbreak in the community and in hospitals. Nasopharyngeal and oropharyngeal swabs are the recommended specimen types for Covid-19 diagnostic testing. The collection of these specimen types requires close contact between healthcare workers and patients and poses a risk of transmission of the virus, causes discomfort and may cause bleeding, especially in patients with condition such as thrombocytopenia. Hence, nasopharyngeal or oropharyngeal swabs are not desirable for sequential monitoring of viral load. Saliva specimens can be obtained easily as the patient is asked to spit into a sterile bottle. The collection of saliva is non-invasive and greatly minimizes the exposure of healthcare workers to Covid-19. Saliva has a high consistency rate of greater than 90% with nasopharyngeal specimens in the detection of respiratory viruses, including coronaviruses. Saliva has also been used in screening respiratory viruses among hospitalized patients without pyrexia or respiratory symptoms. SARS-CoV can be detected in saliva at high titers. Salivary diagnostics is a dynamic field that is being incorporated as part of disease diagnosis, clinical monitoring of systemic health and to make significant clinical decisions for patient care. More research is required to analyze the potential diagnostic of Covid-19 in saliva to develop rapid chair side tests for the detection of Covid-19 and it is also pivotal to improve and develop successful strategies for prevention, especially for dentists and healthcare professionals who are involved in performing aerosol-generating procedures.

Tracking the functional meaning of the human oral-microbiome protein-protein interactions

The interactome - the network of protein-protein interactions (PPIs) within a cell or organism - is technically difficult to assess. Bioinformatic tools can, not only, identify potential PPIs that can be later experimentally validated, but also be used to assign functional meaning to PPIs. Saliva's potential as a non-invasive diagnostic fluid is currently being explored by several research groups. But, in order to fully attain its potential, it is necessary to achieve the full characterization of the mechanisms that take place within this ecosystem. The onset of omics technologies, and specifically of proteomics, delivered a huge set of data that is largely underexplored. Quantitative information relative to proteins within a given context (for example a given disease) can be used by computational algorithms to generate information regarding PPIs. These PPIs can be further analyzed concerning their functional meaning and used to identify potential biomarkers, therapeutic targets, defense and pathogenicity mechanisms. We describe a computational pipeline that can be used to identify and analyze PPIs between human and microbial proteins. The pipeline was tested within the scenario of human PPIs of systemic (Zika Virus infection) and of oral conditions (Periodontal disease) and also in the context of microbial interactions (Candida-Streptococcus) and showed to successfully predict functionally relevant PPIs. The pipeline can be applied to different scientific areas, such as pharmacological research, since a functional meaningful PPI network can provide insights on potential drug targets, and even new uses for existing drugs on the market.

The Role of the Microbiota in the Diabetic Peripheral Artery Disease

Vascular complications of diabetes mellitus represent a major public health problem. Although many steps forward have been made to define the causes and to find the best possible therapies, the problem remains crucial. In recent years, more and more evidences have defined a link between microbiota and the initiation, promotion, and evolution of atherosclerotic disease, even in the diabetic scenario. There is an urgency to develop the knowledge of modern medicine about the link between gut microbiota and its host's metabolic pathways, and it would be useful to understand and justify the interindividual diversity of clinical disease presentation of diabetic vascular complication even if an optimization of pharmacological treatment has been made or in the case of young patients where hypertension, dyslipidemia, and diabetes are not able to justify a very quick progress of atherosclerotic process. The aim of the present review is to gather all the best available evidence in this regard and to define a new role of the microbiota in this field, from biomarker to possible therapeutic target.

A New Approach for the Diagnosis of Systemic and Oral Diseases Based on Salivary Biomolecules

Early diagnosis represents the target of contemporary medicine and has an important role in the prognosis and further treatment. Saliva is a biofluid that generated a high interest among researchers due to its multiple advantages over other body fluids. The multitude of components that can act as biomarkers influenced the existing technologies to develop protocols that could allow saliva to become the new noninvasive diagnostic method. Saliva as a diagnostic tool can bring substantial addition to the diagnostic armamentarium, providing important information about oral and general health. The diagnostic applications of saliva extended and had a rapid evolution due to the advancement in salivaomics. The present review summarizes the latest researches in saliva-related studies and explores the information and correlations that saliva can offer regarding the systemic and oral diseases, highlighting its great potential of diagnosis. It is expected that in the future specific guidelines and results regarding the salivary diagnostics are to be available, together with high-sensitivity and specificity tests for multiple systemic and oral diseases.

Serum Tumor Marker Carbohydrate Antigen 125 Levels and Carotid Atherosclerosis in Patients with Coronary Artery Disease

Objective

We assessed the correlation between serum carbohydrate antigen 125 (CA125) and carotid intima-media thickness (cIMT) in patients with coronary artery disease (CAD).

Methods

We collected 518 CAD patients from the cardiovascular disease center in our hospital, and all cIMT values were measured in patients with CAD.

Results

The serum CA125 concentrations were found to be increased in CAD patients with early carotid atherosclerosis compared with patients without early carotid atherosclerosis (20.1±7.72 vs. 17.7±6.41 U/mL, p<0.001). The cIMT values were increased in patients with higher serum CA-125 levels than those with lower serum CA-125 concentrations (1.16±0.32 vs. 0.98±0.29 mm, p<0.001). There was a positive correlation between serum CA125 and cIMT in CAD patients (r=0.262, p<0.001). Moreover, the serum CA125 concentrations also were positively correlated with cIMT in subjects with early carotid atherosclerosis and without early carotid atherosclerosis (r=0.255, p<0.001; r=0.189, p=0.002). We found that serum CA-125 concentrations were independently correlated with cIMT (beta = 0.293, p<0.001) in multiple linear regression analysis.

Conclusions

We found that serum CA125 concentrations were positively correlated with cIMT in CAD patients, serum CA125 might be a potential biochemical marker for the estimation of atherosclerosis in patients with CAD.

Perceived discrimination is associated with the inflammatory response to acute laboratory stress in women at risk for cardiovascular disease

Cardiovascular disease (CVD) is the leading cause of death in the United States and exacts a disproportionate toll on minorities. Growing evidence demonstrates that perceived discrimination is a significant contributing factor to psychological distress, chronic low-grade inflammation, and cardiovascular health. However, little is known regarding the extent to which perceived discrimination contributes to the inflammatory response to acute stress. Therefore, the purpose of this study was to examine the influence of perceived discrimination on the inflammatory response to a laboratory acute stress paradigm in women at risk for CVD. A cross-sectional sample of 99 postmenopausal women (50 African American and 49 non-Hispanic White) (mean age 60.2 years) with at least two risk factors for CVD underwent the Trier Social Stress Test (TSST). Subjects completed the Detroit Area Study Discrimination Scale (DAS-DS) Everyday Discrimination subscale and provided blood and saliva samples prior to the TSST and every 15 min up to 90 min post-TSST to measure a pro-inflammatory cytokine, interleukin-6 (IL-6). Perceived discrimination was significantly associated with the salivary IL-6 response to the TSST (b = 0.49, SE = 0.13, p = <0.001) controlling for age, race, marital status, household income, BMI, statin use, childhood maltreatment, depressive symptoms, and subjective social status. Women who reported higher levels of perceived discrimination had higher levels of salivary IL-6 at baseline and following the TSST as compared to women who reported lower levels of perceived discrimination. Results suggest that higher levels of perceived discrimination, regardless of race and socioeconomic status, may heighten levels of inflammation, prior to and following an acute stress exposure. The circulating Il-6 response was associated with BMI only and did not correlate with salivary IL-6. These data suggest that perceived discrimination may contribute to the salivary-IL-6 acute stress response. However, more research is needed to help clarify the complex relationships among stress and salivary proinflammatory cytokines.

Relationship between the burden of major periodontal bacteria and serum lipid profile in a cross-sectional Japanese study

Background

The association of periodontal bacteria with lipid profile alteration remains largely unknown, although it has been suggested that chronic periodontitis increases the atherosclerotic risk. This cross-sectional study investigated the relationship between the prevalence and total burden of periodontal bacteria and serum lipid profile.

Methods

Saliva from enrolled participants was collected to detect 4 major periodontal bacteria (Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Prevotella intermedia) using Polymerase Chain Reaction method. High-density lipoprotein (HDL) cholesterol, triglycerides (TG), and low-density lipoprotein cholesterol were assessed using blood samples. We compared the averages of each lipid in association with the prevalence of each bacterial species, their burden (low, moderate, and high), and the combination of bacterial burden and periodontal status, defined as periodontitis, using the Community Periodontal Index, after adjustment for other potential confounding factors, by employing general linear models with least square means.

Results

A total of 385 Japanese individuals (176 men, 209 women; mean age 69.2 years) were enrolled. The number of bacterial species and their co-existence with periodontitis were significantly related to a decrease in HDL (p for trend < 0.01) and increase in TG (p for trend = 0.04). The adjusted mean HDL levels (mg/dL) in individuals with low, moderate, and high levels of bacterial species were 66.1, 63.0, and 58.9, respectively, and those in the 6 groups defined by combination of the two factors were 67.9, 64.6, 64.3, 65.4, 61.5, and 54.7, respectively.

Conclusion

Periodontal bacterial burden is suggested to be independently involved in lowering serum HDL level. Our findings suggest that bacterial tests in a clinical setting could be a useful approach for predicting the risk of HDL metabolism dysregulation.

Salivary micro RNA as a potential biomarker in oral potentially malignant disorders: A systematic review

Oral potentially malignant disorders (OPMD) are oral mucosal disorders which have a high potential to turn into malignancy. A recent report suggests that 16%–62% of epithelial dysplasia cases of OPMD undergo malignant transformation, showing the need for early detection of malignancy in these disorders. Micro RNA (miRNA) plays an important role in cellular growth, differentiation, apoptosis, and immune response, and hence, deregulation of miRNA is considered a signature of oral carcinogenesis. A search was done using MeSH terms in the PubMed, ScienceDirect databases, hand search, and finally, six studies were included in this systematic review. A total of 167 patients with oral cancer, 78 with OPMDs, 147 healthy controls, and 20 disease controls were analyzed for the expression of salivary miRNAs. Quality assessment based on the Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to obtain a risk of bias chart using Revman 5.3 software and it was proved that the study done by Zahran et al. in 2015 had a low risk of bias. The results of this study revealed upregulated miRNA 184 with an area under the curve (AUC) of 0.86 and miRNA 21 with an AUC of 0.73 and downregulated miRNA 145 with an AUC of 0.68, which proved that these miRNAs are significant in detecting early malignancy in OPMD and should be further analyzed in various populations. This systematic review explored the potential of expression of salivary miRNA in OPMD for future studies. This could pave the way to utilize saliva as a surrogate marker in diagnosing early malignant changes in OPMD.

Salivary microbiome of an urban Indian cohort and patterns linked to subclinical inflammation

OBJECTIVE

To profile salivary microbiomes of an urban-living, healthy Indian cohort and explore associations with proinflammatory status.

METHODS

Fifty-one clinically healthy Indian subjects' salivary microbiomes were analyzed using 16S rRNA Illumina MiSeq sequencing. Community distribution was compared with salivary data from the Human Microbiome Project (HMP). Indian subjects were clustered using microbiome-based "partitioning along medoids" (PAM), and relationships of interleukin-1 beta levels with community composition were analyzed.

RESULTS

Indian subjects presented higher phylogenetic diversity than HMP. Several taxa associated with traditional societies gut microbiomes (Bacteroidales, Paraprevotellaceae, and Spirochaetaceae) were raised. Bifidobacteriaceae and Lactobacillaceae were approximately fourfold greater. A PAM cluster enriched in several Proteobacteria, Actinobacteria, and Bacilli taxa and having almost twofold higher Prevotella to Bacteroides ratio showed significant overrepresentation of subjects within the highest quartile of salivary interleukin-1 beta levels. Abiotrophia, Anaerobacillus, Micrococcus, Aggregatibacter, Halomonas, Propionivivrio, Paracoccus, Mannhemia, unclassified Bradyrhizobiaceae, and Caulobacteraceae were each significant indicators of presence in the highest interleukin-1 beta quartile. 2 OTUs representing Lactobacillus fermentum and Cardiobacterium hominis significantly correlated with interleukin-1 beta levels.

CONCLUSION

The salivary microbiome of this urban-dwelling Indian cohort differed significantly from that of a well-studied Western cohort. Specific community patterns were putatively associated with subclinical inflammation levels.

Relationship of childhood adversity and neighborhood violence to a proinflammatory phenotype in emerging adult African American men: An epigenetic link

African American men (AAM) who are exposed to trauma and adversity during their early life are at greater risk for poor health over their lifespan. Exposure to adversity during critical developmental windows may embed an epigenetic signature that alters expression of genes that regulate stress response systems, including those genes that regulate the inflammatory response to stress. Such an epigenetic signature may increase risk for diseases exacerbated by inflammation, and may contribute to health disparity. The purpose of this study was to evaluate the extent to which exposure to early life adversity influences the psychological, cortisol, and proinflammatory response to acute stress (Trier Social Stress Test - TSST) in emerging adult AAM, ages 18-25years (N=34). Hierarchical linear modeling was used to examine the cortisol and IL-6 pattern of response to the TSST with respect to childhood adversity factors and DNA methylation of the IL-6 promoter. Findings revealed that in response to the TSST, greater levels of childhood trauma and indirect exposure to neighborhood violence were associated with a greater TSST-induced IL-6 response, and a blunted cortisol response. Reduced methylation of the IL6 promoter was related to increased exposure to childhood trauma and greater TSST-induced IL-6 levels. These results support the concept that exposure to childhood adversity amplifies the adult proinflammatory response to stress, which is related to epigenetic signature.

[Application of saliva in disease diagnosis]

Saliva is secreted by salivary glands and performs a variety of functions, including mouth cleaning and protection, antibacterial activity, and digestion. With the rapid progress in salivaomics, saliva became recognized as a potential pool of biological markers. Being a non-invasive and safe source, saliva is a potential substitute for blood in diagnosis and prognosis of diseases. This review summarizes the latest advancement in saliva-related studies and presents the potential value of saliva in early diagnosis of oral diseases, such as dental caries, periodontal disease, cancer, diabetes, and other systemic disorders. Saliva biomarkers can reveal changes ranging from changes in biochemical index, DNA, RNA, and proteins to the diversification of microbiota structure. By integrating recent data, this paper discusses the clinical significance and application prospect of saliva in early diagnosis of diseases and in translational and precision medicine.

Saliva in the diagnosis of diseases

Saliva is secreted from the salivary glands and has multiple functions, including mouth cleaning and protection, antibacterial effects and digestion. With the rapid advancement in salivaomics, saliva is well recognized as a pool of biological markers. Saliva, as a non-invasive and safe source, could be a substitute for blood in the diagnosis and prognosis of diseases. This review summarizes the latest advancements in saliva-related studies and addresses the potential value of saliva in the early diagnosis of oral diseases, such as dental caries and periodontal disease, as well as cancer, diabetes and other systemic disorders. Saliva biomarkers range from changes in the biochemical indices of DNA, RNA and proteins to the diversification of microbiota structures. This study integrates data reported in the recent literature and discusses the clinical significance and prospects for the application of saliva in the early diagnosis of diseases, translational medicine and precision medicine.

Salivary and serum adiponectin and C-reactive protein levels in acute myocardial infarction related to body mass index and oral health

BACKGROUND AND OBJECTIVE

Adiponectin is produced by adipose cells and is considered an anti-inflammatory molecule. In contrast, C-reactive protein (CRP) has been identified as a hallmark of systemic inflammation and used as a risk marker of cardiovascular disease (CVD). Of interest was the relationship of these two biomarkers to oral health and CVD risk.

MATERIAL AND METHODS

This investigation examined these two molecules in serum and unstimulated whole saliva of patients within 48 h of an acute myocardial infarction (AMI) compared to control subjects. We hypothesized a differential response in these biomolecules resulting from the heart attack that would be affected by both the body mass index and oral health characteristics of the individuals.

RESULTS

Significantly lower adiponectin levels were observed in the serum of patients with AMI. Serum adiponectin in both groups and salivary adiponectin in patients with AMI decreased with increasing body mass index. Oral health was significantly worse in patients with AMI, and both serum and salivary adiponectin were elevated with better oral health in control subjects. Serum CRP levels were increased in patients with AMI regardless of their oral health, and both serum and salivary CRP were significantly elevated in S-T wave elevated patients with MI.

CONCLUSIONS

These initial data provide evidence relating obesity and oral health to salivary and serum analyte levels that occur in association with cardiac events. Relationships have been described between CVD risk and periodontal disease. Additionally, various systemic inflammatory biomarkers appear to reflect both the CVD risk and the extent/severity of periodontitis. Our findings indicated that oral health and obesity contribute to altering levels of these salivary and serum analytes in association with cardiac events. The potential that serum and/or salivary biomarkers could aid in evaluating CVD risk requires knowledge regarding how the oral health of the individual would impact the effectiveness of these biological measures.

Minority stress and inflammatory mediators: covering moderates associations between perceived discrimination and salivary interleukin-6 in gay men

Physical health disparities by sexual orientation are widespread yet under-investigated. Drawing upon theories of biological embedding of social adversity, we tested whether minority stress (in the form of perceived discrimination) is associated with salivary interleukin-6 (IL-6), an inflammatory mediator. Furthermore, we examined whether covering, a strategy involving downplaying a stigmatized social identity, modified this association. A community sample (N = 99) of gay men (n = 78) and lesbian women (n = 21) completed self-report measures of minority stress and identity management and provided saliva samples which were assayed for IL-6. Among gay men, results from generalized linear models supported a hypothesized interaction between perceived discrimination and covering, such that perceived discrimination was predictive of higher levels of IL-6 for those who engaged in less covering but not for those who engaged in more covering. This interaction was robust to a number of potential covariates (alcohol, medication, body mass index, race and age). Results for lesbian women suggested a different pattern: the only statistically significant association detected was between greater perceived discrimination and lower levels of IL-6. Findings from the current study point to an important role for inflammatory processes in understanding and remediating health disparities based upon sexual orientation that stem from exposure to prejudice and discrimination.

Factors Significantly Associated With the Increased Prevalence of Carotid Atherosclerosis in a Northeast Chinese Middle-aged and Elderly Population: A Cross-sectional Study

Carotid atherosclerosis is associated with many serious cardiovascular diseases; hence, it is necessary to identify factors related to its occurrence in order to develop preventive and therapeutic strategies. This study was conducted to identify risk factors associated with carotid atherosclerosis among the population residing in Northeast China.This epidemiological survey was conducted in a representative group of relatively healthy community residents. All participants answered questions about their medical histories and underwent physical examination, blood biochemical analysis, and ultrasonography examinations of their necks and abdomens. The prevalence rates of carotid atherosclerosis under different factors and conditions were then analyzed.The results of this study showed that age, gender, and diabetes significantly affected the prevalence of carotid atherosclerosis in this Northeast Chinese population. In addition, gender-based subgroup analysis revealed additional factors correlated with the prevalence of carotid atherosclerosis in men or women, although their correlations were not significant in the overall population. While high serum TC and LDL-C levels were risk factors for carotid atherosclerosis in men, it showed no clear correlation with the prevalence of carotid atherosclerosis in women. In contrast, the prevalence of carotid atherosclerosis in female participants with high serum TG level, hypertension, obesity and nonalcoholic fatty liver disease were higher than that of the control population, a trend not observed in male participants.Older age, male sex, and diabetes were independently associated with increased risk of carotid atherosclerosis in Northeast China. These findings could lead to improved screening for carotid atherosclerosis for better disease management.

Association between Bacterial Infection and Peripheral Vascular Disease: A Review

There are an increasing number of data showing a clinically important association between bacterial infection and peripheral artery disease (PAD). Bacteria suspected of being involved in PAD pathogenesis are: periodontal bacteria, gut microbiota, Helicobacter pylori, and Chlamydia pneumoniae. Infectious agents may be involved in the pathogenesis of atherosclerosis via activation of a systemic or local host immunological response to contamination of extravascular tissues or the vascular wall, respectively. A systemic immunological reaction may damage vascular walls in the course of autoimmunological cross-reactions between anti-pathogen antibodies and host vascular antigens (immunological mimicry), pathogen burden mechanisms (nonspecific activation of inflammatory processes in the vascular wall), and neuroendocrine-immune cross-talk. Besides activating the inflammatory pathway, bacterial infection may trigger PAD progression or exacerbation by enhancement of platelet reactivity, by a stimulatory effect on von Willebrand factor binding, factor VIII, fibrinogen, P-selectin activation, disturbances in plasma lipids, increase in oxidative stress, and resistance to insulin. Local inflammatory host reaction and induction of atherosclerotic plaque progression and/or instability result mainly from atherosclerotic plaque colonization by microorganisms. Despite these premises, the role of bacterial infection in PAD pathogenesis should still be recognized as controversial, and randomized, controlled trials are required to evaluate the outcome of periodontal or gut bacteria modification (through diet, prebiotics, and probiotics) or eradication (using antibiotics) in hard and surrogate cardiovascular endpoints.