Acute Myocardial Infarction is Reflected in Salivary Matrix Metalloproteinase-8 Activation Level

Correlations between different protein species of oral rinse MMP-8 and patient-related factors

OBJECTIVES

The aim of this study is to examine correlations between different oral rinse matrix metalloproteinase (MMP)-8 protein species in western blot (WB) analysis, quantitative MMP-8 measurements, and patient-related factors. Elevated activated MMP-8 (aMMP-8) associate with periodontitis and a diagnostic point-of-care technology has been developed based on aMMP-8. In WB, different MMP-8 protein species can be analyzed. Relative abundancy of fragmented 20-25 kDa forms in WB has been associated with and reflects MMP-8 activation and related fragmentation and elevated quantitative aMMP-8 measurements.

MATERIAL AND METHODS

A random sample of 192 participants from a periodontal disease screening study was used for this study. Oral rinse samples for biomarker analyses were collected before clinical periodontal examinations. aMMP-8 immunofluorometric (IFMA) and WB analysis (utilizing the same monoclonal antibody, 8708), polymorphonuclear leukocyte (PMN) elastase activity test and tissue inhibitor of metalloproteinases (TIMP)-1 ELISA levels were performed from the oral rinse samples. Distinct MMP-8 protein species were differentiated in the WB analysis. Principal component (PC) analysis was conducted to explore correlation patterns between the different species. Adjusted correlation analysis between the extracted PCs of WB and aMMP-8 IFMA levels and multilevel regression analysis were conducted to explore if the other periodontal disease-related biomarkers and clinical surrogate measures and patient-related factors are co-variating with the extracted components.

RESULTS

Distinct correlation patterns between the MMP-8 protein species were observed. The first four PCs explained 89% of the whole variance in PC analysis. Statistically significant correlation (p < 0.05) were observed as follows: PC1 positively with 21 kDa (r = .69) and 25 kDa fragments (r = .55) and negatively with 150 kDa complexes (r = -.46). PC2 correlated with 45 (r = .70) and 55 kDa (r = .65) activated forms, PC3 with 70-80 kDa latent proforms (r = .63) and 90-100 kDa complexes (r = .67), and PC4 with 35 kDa fragments (r = .81). There were significant correlations between quantitative (IFMA) aMMP-8 measurements and PC1 (p < 0.001), PC2 (<0.05) and PC3 (<0.05) but not with PC4. In multilevel regression models age, PMN elastase activity, TIMP-1 levels, and a number of 4-5 mm periodontal pockets were associated with PC1, nonsmoking with PC2, age and PMN elastase activity with PC3, and age and smoking with PC4.

CONCLUSIONS

Relative abundancy of fragmented 21-25 kDa protein species was correlated with the quantitative aMMP-8 (IFMA) measurements, which is in line with previous results. Different patient-related factors (smoking, age, proteolytic activity) may modify the formation of different MMP-8 protein species in oral rinse samples and may cause variability in quantitative aMMP-8 measurement.

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.

Is TIMP-1 a biomarker for periodontal disease? A systematic review and meta-analysis

Objective

One of the most important families of proteases associated with periodontal disease is the family of the matrix metalloproteinases (MMPs). Their activity is regulated by tissue inhibitors of metalloproteinases (TIMPs), and an imbalance between MMP activity and regulation by TIMPs has been associated with the progression of periodontal disease. This strong interaction between TIMPs and MMPs might be an indication that TIMPs can be used as a biomarker to monitor periodontal disease progression in oral fluids. In particular, TIMP‐1 is a frequently studied biomarker for periodontal diseases. Therefore, the aim of this systematic review was to evaluate the scientific literature regarding TIMP‐1 concentrations in oral fluids of patients suffering from periodontitis or gingivitis in comparison to healthy individuals.

Material and Methods

PubMed/ MedLine and Web of Science databases were searched electronically. Studies that met the inclusion criteria were systematically evaluated and assessed for eligibility and risk of bias. Meta‐analysis was performed through the random effects model to assess the association between periodontitis/gingivitis and TIMP‐1 concentration in stimulated saliva, unstimulated saliva, and gingival crevicular fluid (GCF).

Results

The search strategy provided a total of 322 studies of which 10 studies met all inclusion criteria. Two studies investigated TIMP‐1 concentrations in GCF, three studies in unstimulated saliva, and five studies investigated TIMP‐1 concentrations in stimulated saliva. Three studies revealed that TIMP‐1 levels in oral fluids were significantly decreased in periodontal disease. Meta‐analysis revealed that there is no statistically significant difference between TIMP‐1 concentration in oral fluids of periodontitis/gingivitis patients in comparison to healthy individuals.

Conclusions

This systematic review with meta‐analysis shows that periodontal diseases are not associated with a statistically significant change in TIMP‐1 concentration in oral fluids.

Active matrix metalloproteinase-8 (aMMP-8) point-of-care test (POCT) in the COVID-19 pandemic

INTRODUCTION

Active matrix metalloproteinase (aMMP)-8 utilized in point-of-care testing (POCT) is regarded as a potential biomarker for periodontal and peri-implant diseases. Various host and microbial factors eventually influence the expression, degranulation, levels and activation of aMMP-8. The type of oral fluids (saliva, mouthrinse, gingival crevicular, and peri-implant sulcular fluids [GCF/PISF], respectively) affect the analysis.

AREAS COVERED

With this background, we aimed to review here the recent studies on practical, inexpensive, noninvasive and quantitative mouthrinse and GCF/PISF chair-side POCT lateral flow aMMP-8 immunoassays (PerioSafe and ImplantSafe/ORALyzer) and how they help to detect, predict, monitor the course, treatment and prevention of periodontitis and peri-implantitis. The correlations of aMMP-8 POCT to other independent and catalytic activity assays of MMP-8 are also addressed.

EXPERT OPINION

The mouthrinse aMMP-8 POCT can also detect prediabetes/diabetes and tissue destructive oral side-effects due to the head and neck cancers' radiotherapy. Chlorhexidine and doxycycline can inhibit collagenolytic human neutrophil and GCF aMMP-8. Furthermore, by a set of case-series we demonstrate the potential of mouthrinse aMMP-8 POCT to real-time/online detect periodontitis as a potential risk disease for coronavirus disease 2019 (COVID-19). The clinical interdisciplinary utilization of aMMP-8 POCT requires additional oral, medical, and interdisciplinary studies.

Predictive Periodontitis: The Most Promising Salivary Biomarkers for Early Diagnosis of Periodontitis

The primary cause of tooth loss in the industrialized world is periodontitis, a bacterial anaerobic infection whose pathogenesis is characterized by composite immune response. At present, the diagnose of periodontitis is made by a complete status check of the patient’s periodontal health; full-mouth plaque score, full-mouth bleeding score, probing depth, clinical attachment level, bleeding on probing, recessions, mobility, and migration are evaluated in order to provides a clear picture of the periodontal conditions of a single patient. Chair-side diagnostic tests based on whole saliva could be routinely used by periodontists for a very early diagnosis of periodontitis, monitoring, prognosis, and management of periodontal patients by biomarker detection, whose diagnostic validity is related to sensitivity and specificity. Recent paper reviews and meta-analyses have focused on five promising host derived biomarkers as candidate for early diagnosis of periodontitis: MMP-8 (Metalloproteinase-8), MIP-1α (Macrophage inflammatory protein-1 alpha), IL-1 β (Interleukin-1 beta), IL-6 (Interleukin-6), and HB (Hemoglobin), and their combinations. Chair-side Lab-on-a-chip (LOC) technology may soon become an important part of efforts to detect such biomarkers in saliva medium to improve worldwide periodontal health in developed nations as well as in underserved communities and poor countries. Their applications in preventive and predictive medicine is now fundamental, and is aimed at the early detection of risk factors or the presence or evolution of the disease, and in personalized medicine, which aims to identify tailor-made treatments for individual patients. The aim of the present paper is to be informative about host derived periodontal biomarkers and, in particular, we intend to report information about the most important immune response derived biomarkers and Hemoglobin as candidates to be routinely utilized in order to obtain a chair-side early diagnosis of periodontal disease.

Risk of acute and chronic coronary syndrome in a population with periodontitis: A cohort study

OBJECTIVE

To investigate the role of periodontitis in the risk of acute and chronic coronary syndrome with compounding factors, including sociodemographic factors and medication use.

METHODS

This retrospective cohort study used nationwide, population-based data from the Korean National Health Insurance Service-Health Screening Cohort database (514,866 individuals, 40-79 years). Propensity score matching was used for analysis. Information of subjects for 12 years was included. Socioeconomic and clinical factors were recorded and analysed.

RESULTS

The periodontitis group had a greater risk of overall acute coronary syndrome (hazard ratio [95% confidence interval] =1.25 [1.15, 1.35], p < .001) and non-fatal acute coronary syndrome (1.26 [1.16, 1.37], p < .001). The hazard ratio for chronic coronary syndrome was higher in patients with periodontitis (1.35 [1.25, 1.46], p < .001). The cumulative incidence of both acute and chronic coronary syndrome gradually increased, and the hazard ratios reached 1.25 and 1.35 at the 12-year follow-up, respectively. Subgroup analysis revealed that periodontitis had a significantly greater link with acute coronary syndrome incidence in males, younger adults, smokers and subjects without hypertension (p < .01) and with chronic coronary syndrome incidence in smokers, subjects without hypertension and subjects without dyslipidaemia (p < .05).

CONCLUSIONS

Periodontitis is associated with an increased risk of acute and chronic coronary syndrome.

Salivary biomarkers in cardiovascular disease: An insight into the current evidence

Cardiovascular diseases (CVDs) are the most common cause of mortality worldwide. In acute cardiovascular conditions, time is a crucial player in the outcomes of disease management. Given the ease and noninvasiveness of obtaining saliva, salivary biomarkers may provide a rapid and efficient diagnosis of CVD. Here, we reviewed the published data on the value of salivary molecules for diagnosis of CVD, especially in acute care settings. In this review, we show that some biomarkers such as salivary creatinine kinase myocardial band, C-reactive protein, troponin-1, and myoglobin exhibited promising diagnostic values that were comparable to their serum counterparts. Other molecules were also investigated and showed controversial results, including myeloperoxidase, brain natriuretic peptide, and some oxidative stress markers. Based on our review, we concluded that the clinical use of salivary biomarkers to diagnose CVD is promising; however, it is still in the early stage of development. Further studies are needed to validate these findings, determine cutoff values for diagnosis, and compare them to other established biomarkers currently in clinical use.

Biomarkers of acute myocardial infarction: diagnostic and prognostic value. Part 2 (Literature review)

In the second part of the review, we continue the discussion of biomarkers that have a diagnostic and prognostic significance in acute myocardial infarction (AMI). The study of the AMI pathophysiology through the experimental and clinical research contributes to the discovery of new regulatory molecules and pathogenetic mechanisms underlying AMI. At the same time, many molecules involved in the pathogenesis of AMI can be used as effective biomarkers for the diagnosis and prediction of AMI. This article discusses in detail the diagnostic and prognostic value of inflammatory biomarkers of AMI (C-reactive protein, interleukin-6, tumor necrosis factor-alpha, myeloperoxidase, matrix metalloproteinases, soluble form of CD40 ligand, procalcitonin, placental growth factor) and a number of recently discovered new biomarkers of AMI (microribonucleic acids, galectin-3, stimulating growth factor expressed by gene 2, growth differentiation factor 15, proprotein convertase of subtilisin-kexin type 9).

An Oral Rinse Active Matrix Metalloproteinase-8 Point-of-Care Immunotest May Be Less Accurate in Patients with Crohn's Disease

The diagnostic accuracy of point-of-care (PoC) applications may be compromised in individuals with additional inflammatory conditions. This cross-sectional study examined the performance of a commercial oral rinse active matrix metalloproteinase-8 (aMMP-8) PoC immunotest in individuals with (n = 47) and without Crohn's disease (CD) (n = 41). Oral rinse collected from the participants was analyzed by the PoC immunotest. Molecular forms and fragments of salivary MMP-8 were detected by western immunoblotting. The sensitivity of the immunotest for periodontitis was 60.0% in the CD group and 90.0% in the control group. The respective specificity was 75.0% and 80.0%. In both groups, clinical diagnosis of periodontitis exhibited a significant association with the immunotest results, however, the odds ratio (OR) was more than ten-fold in controls (OR 54.3, 95% CI: 3.1-953, p = 0.006) in comparison to CD patients (OR 5.2, 95% CI: 1.3-21.6, p = 0.022). According to Western immunoblot results, the immunotest MMP-8 positivity was not related to elevated levels of molecular forms and fragments of MMP-8 in the CD group, as in the control group. The diagnostic accuracy of the aMMP-8 PoC oral rinse immunotest is reduced in CD patients, which may be related to lower levels or undetectable complexes.

Salivary biomarkers for diagnosis of systemic diseases and malignant tumors. A systematic review

Background

Saliva evaluation could be a possible alternative to blood and/or tissue analyses, for researching specific molecules associated to the presence of systemic diseases and malignancies. The present systematic review has been designed in order to answer to the question “are there significant associations between specific salivary biomarkers and diagnosis of systemic diseases or malignancies?”.

Material and Methods

The Preferred Reporting Item for Systematic Reviews and Meta-analysis (PRISMA) statement was used to guide the review. The combinations of “saliva” and “systemic diseases” or “diagnosis” or “biomarkers” or “cancers” or “carcinoma” or “tumors”, were used to search Medline, Scopus and Web of Science databases. Endpoint of research has been set at May 2019. Studies were classified into 3 groups according to the type of disease investigated for diagnosis: 1) malignant tumors; 2) neurologic diseases and 3) inflammatory/metabolic/cardiovascular diseases. Assessment of quality has been assigned according to a series of questions proposed by the National Institute of Health. Level of evidence was assessed using the categories proposed in the Oxford Center for Evidence-Based medicine (CEMB) levels for diagnosis (2011).

Results

Seventy-nine studies met the inclusion and exclusion criteria. Fifty-one (64%) investigated malignant tumors, 14 (17.5%) neurologic and 14 (18.5%) inflammatory/cardiovascular/metabolic diseases. Among studies investigating malignant tumors, 12 (23.5%) were scored as “good” and 11 of these reported statistically significant associations between salivary molecules and pathology. Two and 5 studies were found to have a good quality, among those evaluating the association between salivary biomarkers and neurologic and inflammatory/metabolic/cardiovascular diseases, respectively.

Conclusions

The present systematic review confirms the existence of some “good” quality evidence to support the role of peculiar salivary biomarkers for diagnosis of systemic diseases (e.g. lung cancer and EGFR).

Key words:Salivary diagnostics, biomarkers, systemic diseases, malignant tumors, early diagnosis.

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.

[Clinical and Diagnostic Value of Cardiac Markers in Human Biological Fluids]

The article is devoted to problems of clinical-diagnostic value of determination of cardio-specific troponins in human biological fluids. Improvement of laboratory instrumentation and emergence of high sensitivity methods of analysis have allowed to identify troponins in urine, dialysate, and oral fluid. In the review we present actual information related to measurement of troponins in blood serum, data on testing of cardio-specific troponins in urine, dialysate, and oral fluid. Special attention is paid to determination of some cardiomarkers in oral fluid with thorough analysis of diagnostic value and effectiveness of the conducted studies.

Association of the salivary triggering receptor expressed on myeloid cells/its ligand peptidoglycan recognition protein 1 axis with oral inflammation in kidney disease

BACKGROUND

Triggering receptor expressed on myeloid cells (TREM-1) is a cell-surface receptor involved in amplification of inflammatory response to bacterial infections, along with its ligand peptidoglycan recognition protein 1 (PGLYRP1). TREM-1 is shed by matrix metalloproteinases (MMPs) to its soluble (s) form. The aim of the study is to investigate association of sTREM-1 and PGLYRP1 with oral inflammatory burden among patients with chronic kidney disease (CKD) at predialysis and posttransplantation stages.

METHODS

One hundred forty-four patients with CKD were examined at predialysis, and oral infection foci were treated prior to kidney transplantation. Fifty-three patients were available for follow-up after transplantation. Oral inflammatory burden was assessed by the Periodontal Inflammatory Burden Index (PIBI) and Total Dental Index. sTREM-1, PGLYRP1, and interleukin (IL)-1β were measured in saliva by enzyme-linked immunosorbent assay, and MMP-8 was measured by immunofluorometric assay.

RESULTS

In the predialysis stage, sTREM-1 and PGLYRP1 were positively associated with IL-1β, MMP-8, and PIBI. More specifically, patients with deeper probing depth (PD) (at least two sites with ≥6 mm) had higher concentrations of salivary sTREM-1 and PGLYRP1 compared with those with shallower PD. Higher concentrations of PGLYRP1 and IL-1β were associated with a higher number of teeth (> 25). On follow-up, higher PGLYRP1 and sTREM-1 were associated with one or more sites with ≥4 mm PD.

CONCLUSIONS

sTREM-1 and PGLYRP1 are elevated in patients with CKD with poor oral health and positively correlate with number of active periodontal pockets after oral infection therapy. Moreover, they positively correlate with MMP-8 and IL-1β. Hence, the salivary sTREM-1/PGLYRP1 axis could be useful as a diagnostic marker for oral infection within patients with CKD.

Matrix metalloproteinases and inhibitors in dentistry

OBJECTIVES

Matrix metalloproteinase (MMP) expression has been associated with tissue development, invasive cancer cell behavior, and inflammation. The associations of increased expression of MMPs with diseases have led to intensive research activities to develop MMP inhibitors. Here, the questions are addressed which associations between increased levels of any MMP with dental diseases may be cause or consequence, whether MMP levels may be of diagnostic value and whether and which MMP inhibitors need further investigations for use in dental diseases.

METHODS

To study the role of MMPs and to discriminate between cause or consequence, the literature about measurements of MMPs and about the use of inhibitory drugs and genetic knockout animal models in dentistry was compared.

RESULTS

The only FDA-approved treatment with MMP inhibitors is tetracyclines for periodontitis, whereas a diagnostic test for activated MMP-8 in oral fluids is valued in practical periodontology. The MMP literature in dentistry is artificially skewed to the gelatinases MMP-2 and MMP-9 and to enamelysin, alias MMP-20. The basis for this observation is, respectively, the widely used and sensitive technique of gelatin zymography and enamel proteins as substrates of MMP-20. Studies on additional MMPs are gaining interest in dentistry and MMP inhibitors may provide new applications. In addition, drugs with proven effects for the treatment of dental diseases may be found to act through MMP inhibition.

CONCLUSION AND RELEVANCE

In conclusion, research on MMPs and inhibitors may provide practical applications beyond diagnosis and treatment of periodontitis and will be, directly or indirectly, beneficial for patients with dental or periodontal diseases.

MMP-2 salivary activity in type 2 diabetes mellitus patients

BACKGROUND

Type 2 diabetes mellitus (T2DM) and periodontitis are chronic inflammatory diseases with a bidirectional relationship. The uncontrolled levels of glucose in T2DM patients change the pathophysiology and balance of inflammatory mediators. Matrix Metalloproteinase-2 (MMP-2) is a zinc-dependent endopeptidase that is responsible for tissue remodeling and degradation of the extracellular matrix in periodontal tissue. Therefore, the uncontrolled levels of glucose in T2DM could lead to an imbalance in MMP-2 activity in saliva, favoring the development of periodontitis.

METHODS

Ninety-seven T2DM patients from Hospital Dr. Donato Alarcon were included in the study. Following clinical examination, the patients were classified into four groups according to the presence and degree of periodontal disease and glycemic control. Blood and whole saliva samples (WSS) were collected from each patient. Blood samples were used for Hba1c and polymorphonuclear cells count determination, while WSS were used to determine MMP-2 activity, TIMP-1 and nitrite. MMP-2 activity was determined by zymography. TIMP-1 were determined by Western blotting, and nitric oxide (NO) levels were determined by the Griess method.

RESULTS

Of the 97 patients with T2DM, 66 had periodontitis of different severities: 18 patients had mild periodontitis, 15 had moderate and 33 had severe. Salivary MMP-2 activity, HbA1c and TIMP-1 were positively correlated with the severity of periodontitis. On the other hand, the increase in HbA1c was negatively correlated with MMP-2 activity and quantity of TIMP-1 but was positively correlated with nitrite levels.

CONCLUSIONS

T2DM with glycemic uncontrol conditions, distinct clinical alterations in periodontal tissue were identified, including a decrease in the gingival redness, increased the clinical attachment loss and imbalance of MMP-2/TIMP-1, as the possible causes of disorders promoting the progression of periodontitis. Accelerated periodontitis development with poor glycemic uncontrol likely results from the altered response of host defenses and decreased activity of polymorphonuclear cells. Taken together, these findings identify MMP-2 as a promising molecular market for periodontitis.

Molecular forms and fragments of salivary MMP-8 in relation to periodontitis

AIM

To investigate the molecular forms of salivary matrix metalloproteinase (MMP)-8 in relation to periodontitis.

MATERIALS AND METHODS

Molecular forms, degree of activation and fragmentation of neutrophilic and mesenchymal-type MMP-8 isoforms were analysed from salivary samples of 81 subjects with generalized periodontitis, 63 subjects with localized periodontitis and 79 subjects without pocket teeth, by using western-immunoblots with computer quantitation. In addition, human recombinant proMMP-8 was in vitro activated by Treponema denticola chymotrypsin-like protease (Td-CTLP), sodium hypochlorite (NaOCl, 1 mM, oxidant) or amino phenyl mercuric acetate (APMA, 1 mM).

RESULTS

In saliva of periodontitis-affected individuals, MMP-8 is found in multiple forms, that is, complexes, active and pro-forms of neutrophilic and mesenchymal-type MMP-8, and especially 20-27 kDa fragments. The quantity of these fragments was elevated in both localized and generalized forms of periodontitis. Moreover, the tested activators (Td-CTLP, NaOCl and APMA) activated inactive proMMP-8, resulting in fragments of 20-27 kDa, in vitro, and salivary concentrations of T. denticola correlated significantly with salivary levels of fragmented MMP-8.

CONCLUSION

The present results indicate that during the development and progression of periodontitis, MMP-8 appears as activated and fragmented, and treponemal proteases most likely play role in this cascade.

Inflammatory biomarkers in saliva and serum of patients with rheumatoid arthritis with respect to periodontal status

OBJECTIVE

To study prospectively the association of salivary and serum matrix metalloproteinase (MMP)-8, tissue inhibitor of MMPs (TIMP)-1 and interleukin (IL)-6 with periodontal and systemic inflammation in rheumatoid arthritis (RA). We hypothesized that biomarker concentrations reflect inflammation.

METHODS

Fifty three early untreated RA (ERA) and 28 chronic RA (CRA) patients, underwent rheumatological and dental examinations at baseline and one year later after starting first conventional or biological disease modifying antirheumatic drug. We included 43 control subjects. Saliva and serum samples were analyzed for MMP-8, TIMP-1 and IL-6. Periodontal health was assessed by bleeding on probing (BOP), pocket depth (PD) and periodontal inflammatory burden index (PIBI); RA disease activity was assessed by disease activity score DAS28. Joint destruction was analyzed by the modified Sharp-van der Heijde (SHS) method.

RESULTS

Serum MMP-8 (p < .001; p < .001) and IL-6 (p < .001; p = .002) were significantly higher in CRA vs. other study groups during the study. Salivary MMP-8 (p = .010) and IL-6 (p = .010) were significantly higher in ERA vs. other study groups at baseline. Salivary MMP-8 was associated with periodontal parameters.

CONCLUSION

Elevated serum concentrations of MMP-8 and IL-6 in CRA patients reflected chronic RA, while elevated salivary concentrations of MMP-8 levels in ERA patients reflected increased periodontal inflammation. Key messages Concentrations of inflammatory biomarkers in serum and saliva were different between patients with RA and healthy controls. Concentrations of MMP-8 and of IL-6 in serum were elevated in patients with chronic RA reflecting joint inflammation and the burden of established RA. Concentrations of MMP-8 in saliva was elevated already at the early stage of RA and the level of salivary MMP-8 was associated with poor periodontal health both in patients with early and in those with chronic RA.

Genes associated with inflammation and the cell cycle may serve as biomarkers for the diagnosis and prognosis of acute myocardial infarction in a Chinese population

The present study aimed to identify biomarkers for the clinical diagnosis of acute myocardial infarction (AMI) in a Chinese population using microarray data collected from the Gene Expression Omnibus database under accession number GSE97320. This included the peripheral blood samples of three patients with AMI and three controls. Differentially expressed genes (DEGs) were identified using the limma package and protein-protein interaction networks were constructed using data from the Search Tool for the Retrieval of Interacting Genes database, followed by module analysis to screen for hub genes. Functional enrichment analyses were performed using the Database for Annotation, Visualization and Integrated Discovery. The identified genes were verified by overlapping with the target genes of microRNAs (miRs) known to be associated with AMI, as well as the DEGs identified in other AMI datasets, including GSE24519, GSE34198 and GSE48060. As a result, 752 DEGs (449 upregulated and 303 downregulated) were identified in the GSE97320 dataset. The upregulated DEGs were predicted to participate in inflammatory pathways, including the toll-like receptor (TLR) signaling pathway, including ras-related C3 botulinum toxin substrate 1 (RAC1), TLR4, C-C motif chemokine receptor (CCR)1; cytokine-cytokine receptor interaction, including signal transducer and activator of transcription (STAT)3; chemokine signaling pathway, including CCR10; pathways associated with cancer, including colony stimulating factor 3 receptor (CSF3R); and leukocyte transendothelial migration, including matrix metallopeptidase 9 (MMP9). The downregulated DEGs were associated with the cell cycle, including alstrom syndrome protein 1 (ALMS1). These conclusions were made following functional analysis of the genes in the three identified modules. MMP9, TLR4, STAT3, CCR1 and ALMS1 were regulated by miR-21-5p, whereas RAC1 was regulated by miR-30c-5p. A comparison among the four datasets confirmed the roles of CSF3R and CCR10. HtrA serine peptidase 1 (HTRA1) was the only gene associated with both mortality and recurrence. In conclusion, inflammation-associated genes, including STAT3, CCR1, RAC1, MMP9, CCR10, CSF3R and HTRA1, as well as cell cycle-associated genes such as ALMS1, may be biomarkers for the diagnosis and prognosis of AMI in Chinese people.

Salivary biomarkers and cardiovascular disease: a systematic review

Background:

The purpose of this systematic review is to summarize the literature examining associations between salivary biomarkers and cardiovascular disease (CVD) status.

Contents:

An advanced search was conducted using MeSH terms related to salivary biomarkers and CVD, and entered into the PubMed, Web of Science, and Google Scholar search databases. Four hundred and thirty-three records were narrowed to 22 accepted articles. Included titles were assessed for quality using the Newcastle-Ottawa scale, and ranked into categories of low, moderate, or high.

Summary:

A total of 40 salivary biomarkers were analyzed among accepted articles. The most studied markers were salivary creatine kinase isoform MB, C-reactive protein (CRP), matrix metalloproteinase-9, troponin I, myeloperoxidase, myoglobin, and brain natriuretic peptide. Salivary CRP provided the most consistent trends. Statistically significant increases of salivary CRP were present with CVD in every study that analyzed it. The remaining six markers demonstrated varying patterns.

Outlook:

Existing studies provide insufficient data to draw definitive conclusions. Current research shows that there is an association between some salivary biomarkers and CVD, but the details of existing studies are conflicting. Despite inconclusive results, the diagnostic potential of saliva shows promise as a non-invasive means of cardiovascular risk assessment.

Ability of salivary biomarkers in the prognostic of systemic and buccal inflammation

Nowadays, there is a growing interest in using saliva as an alternative sample for the diagnosis, prediction and progression of several diseases. It has been established that some molecules found in saliva are related to oral inflammatory processes and systemic health status. Furthermore, it is known that saliva is crucial for the carrying out of different functions in the oral cavity and its role in the local modulation of inflammatory and immune response is being thoroughly studied by the health research community. The aim of this review is to analyze the most important biomarkers which have been utilized in biomedicine during the last two decades in order to establish a correlation between certain specific salivary biomarkers and systemic inflammation. Then, we discuss the utility of total proteins, immunoglobulin A and alpha-amylase as biomarkers for the prognostic of local inflammation after oral surgery.

Key words:Inflammation, salivary biomarkers, systemic disease, buccal surgery, total proteins, inmunoglobulin A, Alpha-amylase.

Analysis of matrix metalloproteinase-8 levels in gingival crevicular fluid and whole mouth fluid among smokers and nonsmokers using enzyme-linked immune-sorbent assay and a novel chair-side test

AIM

To indigenously prepare a chair-side test kit for investigating and comparing the matrix metalloproteinase (MMP)-8 levels in gingival crevicular fluid (GCF) and saliva in patients with healthy periodontium, gingivitis and chronic periodontitis in smokers and nonsmokers. To validate the diagnostic accuracy of indigenously prepared chair-side test against enzyme-linked immune-sorbent assay (ELISA). Furthermore, to assess the effect of nonsurgical periodontal therapy (NSPT) on the levels of MMP-8 in GCF and saliva among the test groups.

MATERIALS AND METHODS

GCF and saliva were collected from 250 subjects. The study population were divided into five groups; health periodontium-nonsmokers (Group 1; n = 50), chronic gingivitis-nonsmokers (Group 2; n = 50), chronic periodontitis-nonsmokers (Group 3; n = 50), chronic gingivitis-smokers (Group 4; n = 50), chronic periodontitis-smokers (Group 5; n = 50). A chair-side test kit was indigenously prepared using polyclonal antibodies (principle of immunochromatography) to detect the MMP-8 levels, and it was validated against ELISA at baseline and 3 months after NSPT.

RESULTS

The chair-side test detected MMP-8 levels with a sensitivity and specificity in accordance with ELISA. MMP-8 levels at baseline were higher in Group 2 and Group 3 as compared to controls (P < 0.05), and decreased after therapy (P < 0.05). MMP-8 levels in GCF were greater than in saliva for all the groups, indicating GCF to be a better sample to detect the MMP levels.

CONCLUSION

The chair-side test detected MMP-8 levels accurately making it a viable chair side diagnostic tool. It was effective for early diagnosis of the periodontal disease among high-risk population such as smokers.

Inflammatory mediators in saliva associated with arterial stiffness and subclinical atherosclerosis

OBJECTIVE

Whereas circulating levels of C-reactive protein (CRP) have been associated with, for example, arterial stiffness, subclinical atherosclerosis and metabolic syndrome, other inflammatory biomarkers with potential interest for these conditions may not be measurable systemically. The predictive value of salivary biomarkers in these contexts has remained largely unexplored. The aim of the present study was to establish the association of different salivary biomarkers of inflammation with subclinical cardiovascular disease.

METHODS

Two hundred and fifty-nine individuals were included in the study. Saliva and plasma samples were collected, and each individual underwent carotid ultrasound and measures of pulse wave velocity and blood pressure. Medical history of previous cardiovascular disease, current medications and smoking were collected by questionnaire.

RESULTS

Salivary levels of CRP, leukotriene B4 (LTB4), prostaglandin E2 (PGE2), matrix metalloproteinase 9 (MMP-9), creatinine and lysozyme were measured. Salivary levels of CRP were significantly correlated with plasma levels (r = 0.73, P < 0.0001). In an age-adjusted and sex-adjusted analysis, salivary CRP was significantly and positively correlated with mean arterial blood pressure, pulse pressure, pulse wave velocity, BMI, metabolic syndrome, waist-to-hip ratio and intima-media thickness. Increasing age and sex-adjusted salivary CRP tertiles were in addition associated with carotid plaques. In a multivariate analysis, CRP and MMP-9 were associated with intima-media thickness, LTB4 and PGE2 with arterial stiffness, and lysozyme with hypertension.

CONCLUSION

Saliva may represent an alternative mean for evaluation of cardiovascular risk.

Salivary Matrix Metalloproteinase-8 and -9 and Myeloperoxidase in Relation to Coronary Heart and Periodontal Diseases: A Subgroup Report from the PAROKRANK Study (Periodontitis and Its Relation to Coronary Artery Disease)

BACKGROUND AND OBJECTIVE

Matrix metalloproteinase (MMP) -8, -9 and myeloperoxidase (MPO) are inflammatory mediators. The potential associations between MMP-8, -9, MPO and their abilities to reflect cardiovascular risk remains to be evaluated in saliva. The objective of this study was to investigate the levels and associations of salivary MMP-8, -9, MPO and tissue inhibitors of metalloproteinase (TIMP)-1 in myocardial infarction (MI) patients and controls with or without periodontitis.

MATERIALS AND METHODS

200 patients with a first MI admitted to coronary care units in Sweden from May 2010 to December 2011 and 200 controls matched for age, gender, residential area and without previous MI were included. Dental examination and saliva sample collection was performed 6-10 weeks after the MI in patients and at baseline in controls. The biomarkers MMP -8, -9, MPO and TIMP-1 were analyzed by time-resolved immunofluorescence assay (IFMA), Western blot and Enzyme-Linked ImmunoSorbent Assay (ELISA).

RESULTS

After compensation for gingivitis, gingival pockets and smoking, the mean salivary levels of MMP-8 (543 vs 440 ng/mL, p = 0.003) and MPO (1899 vs 1637 ng/mL, p = 0.02) were higher in non-MI subjects compared to MI patients. MMP-8, -9 and MPO correlated positively with clinical signs of gingival/periodontal inflammation while TIMP-1 correlated mainly negatively with these signs. The levels of latent and active forms of MMP-8 did not differ between the MI and non-MI groups. Additionally, MMP-8, MPO levels and MMP-8/TIMP-1 ratio were significantly higher in men compared to women with MI.

CONCLUSIONS

This study shows that salivary levels of the analyzed biomarkers are associated with periodontal status. However, these biomarkers could not differentiate between patients with or without a MI. These findings illustrate the importance to consider the influence of oral conditions when analyzing levels of inflammatory salivary biomarkers.

H2 O2 activates matrix metalloproteinases through the nuclear factor kappa B pathway and Ca(2+) signals in human periodontal fibroblasts

BACKGROUND

The mechanisms involved in reactive oxygen species and matrix metalloproteinase (MMP)-mediated periodontal tissue breakdown are unknown.

OBJECTIVE

To determine the effect of H2 O2 in MMP-2 and MMP-9 activity, and the involvement of nuclear factor kappa B (NFκB) and Ca(2+) -mediated signals in human periodontal ligament fibroblasts.

MATERIAL AND METHODS

Primary cultures were characterized for their phenotype and exposed for 24 h to sublethal doses (2.5-10 μm) of H2 O2 or control media. NFκB involvement was evaluated through immunofluorescence of p65 subunit, using the NFκB blocking peptide SN50 and catalase. Ca(2+) signals were analyzed by loading the cells with Fluo4-AM and recording the fluorescence changes in a confocal microscope before and after the addition of H2 O2 . 1,2-bis(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl was used to chelate intracellular Ca(2+) . The activity and levels of MMP-2 and MMP-9 were analyzed by gelatin zymogram and densitometric scanning, and enzyme-linked immunosorbent assay, respectively. Statistical analysis was performed with stata V11.1 software using the ANOVA test.

RESULTS

H2 O2 at concentrations of 2.5-5 μm induced Ca(2+) signaling and NFκB subunit p65 nuclear translocation, whereas catalase, SN50 and BAPTA-AM prevented p65 nuclear translocation. H2 O2 at 2.5-5 μm significantly increased MMP-9 and MMP-2 activity, while SN50 resulted in lower MMP-2 and MMP-9 activity rates compared with controls.

CONCLUSION

Sublethal H2 O2 induces Ca(2+) -dependent NFκB signaling with an increase in MMP gelatinolytic activity in human periodontal ligament.

Can Saliva Proteins Be Used to Predict the Onset of Acute Myocardial Infarction among High-Risk Patients?

Human saliva plays a pivotal role in digesting food and maintaining oral hygiene. The presence of electrolytes, mucus, glycoproteins, enzymes, antibacterial compounds, and gingival crevicular fluid in saliva ensures the optimum condition of oral cavity and general health condition. Saliva collection has been proven non-invasive, convenient, and inexpensive compared to conventional venipuncture procedure. These distinctive advantages provide a promising potential of saliva as a diagnostic fluid. Through comprehensive analysis, an array of salivary proteins and peptides may be beneficial as biomarkers in oral and systemic diseases. In this review, we discuss the utility of human salivary proteomes and tabulate the recent salivary biomarkers found in subjects with acute myocardial infarction as well as respective methods employed. In a clinical setting, since acute myocardial infarction contributes to large cases of mortality worldwide, an early intervention using these biomarkers will provide an effective solution to reduce global heart attack incidence particularly among its high-risk group of type-2 diabetes mellitus patients. The utility of salivary biomarkers will make the prediction of this cardiac event possible due to its reliability hence improve the quality of life of the patients. Current challenges in saliva collection are also addressed to improve the quality of saliva samples and produce robust biomarkers for future use in clinical applications.

Utility of salivary biomarkers for demonstrating acute myocardial infarction

The comparative utility of serum and saliva as diagnostic fluids for identifying biomarkers of acute myocardial infarction (AMI) was investigated. The goal was to determine if salivary biomarkers could facilitate a screening diagnosis of AMI, especially in cases of non-ST elevation MI (NSTEMI), since these cases are not readily identified by electrocardiogram (ECG). Serum and unstimulated whole saliva (UWS) collected from 92 AMI patients within 48 hours of chest pain onset and 105 asymptomatic healthy control individuals were assayed for 13 proteins relevant to cardiovascular disease, by Beadlyte technology (Luminex(®)) and enzyme immunoassays. Data were analyzed with concentration cut-points, ECG findings, logistic regression (LR) (adjusted for matching for age, gender, race, smoking, number of teeth, and oral health status), and classification and regression tree (CART) analysis. A sensitivity analysis was conducted by repetition of the CART analysis in 58 cases and 58 controls, each matched by age and gender. Serum biomarkers demonstrated AMI sensitivity and specificity superior to that of saliva, as determined by LR and CART. The predominant discriminators in serum by LR were troponin I (TnI), B-type natriuretic peptide (BNP), and creatine kinase-MB (CK-MB), and TnI and BNP by CART. In saliva, LR identified C-reactive protein (CRP) as the biomarker most predictive of AMI. A combination of smoking tobacco, UWS CRP, CK-MB, sCD40 ligand, gender, and number of teeth identified AMI in the CART decision trees. When ECG findings, salivary biomarkers, and confounders were included, AMI was predicted with 80.0% sensitivity and 100% specificity. These analyses support the potential utility of salivary biomarker measurements used with ECG for the identification of AMI. Thus, saliva-based tests may provide additional diagnostic screening information in the clinical course for patients suspected of having an AMI.

Salivary MMPs, TIMPs, and MPO levels in periodontal disease patients and controls

BACKGROUND

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases with an important role in physiological and pathological remodeling. Their activity is regulated by tissue inhibitors of matrix metalloproteinases (TIMPs). Excess MMPs and myeloperoxidase (MPO) activity have been associated with loss of tooth supporting tissues in periodontal disease (PD). We investigate the changes in salivary MMP-8, MMP-9, TIMP-1, TIMP-2, and MPO concentrations during PD treatment and compare results with plasma levels.

METHODS

MMP-8, MMP-9, TIMP-1 and TIMP-2 were analyzed by ELISA. Gelatinolytic activity of MMP-9 forms was determined by zymography, and the MPO activity was determined by colorimetric assay.

RESULTS

Subjects were divided into 2 groups: PD and control, which were further divided into 2 subgroups each, namely PD before (PB) and after 3 months (PA) of non-surgical periodontal therapy, and healthy volunteers at baseline (CB) and 3months after baseline (CA). Subgroup PA presented lower gelatinolytic activity and MMP-8 and TIMP-2 concentrations in the saliva compared with PB (p<0.05). The MPO activity was higher in PB compared with CB (p<0.05). There were significant correlations between the gelatinolytic activity of the saliva and MMP-8 and MMP-9 plasma levels. There was a significant correlation between plasma and saliva TIMP-2 levels.

CONCLUSION

These results suggest attenuation of some inflammatory markers in the saliva and plasma after PD treatment. Moreover, correlations between salivary and plasma levels exist for some of these markers.