Comparative Evaluation of Cytokines in Gingival Crevicular Fluid and Saliva of Patients with Aggressive Periodontitis

Salivary IL-1β, IL-6, and IL-10 Are Key Biomarkers of Periodontitis Severity

To explore severity and progression biomarkers, we examined the clinical relevance of multiple cytokines and mediators involved in the inflammatory response in periodontitis. A cohort of 68 patients was enrolled in the study and periodontal status assessed by the current classification of periodontal diseases. Immune mediators present in saliva, of both patients and healthy controls, were quantified using a Legendplex-13 panel. Clinic parameters were significantly higher in PD patients compared with HC, with a strong significant association with the disease severity (stage) (p < 0.001), but not with progression (grade). The panel of immune mediators evidenced elevated levels of pro-inflammatory cytokines IL-6 and IL-1β as disease established (p < 0.01). IL-1β/IL-1RA ratio was increased in PD patients, being associated with disease stage. An anti-inflammatory response was spotted by higher IL-10. Lower levels of IL-23 and IP-10 were associated with disease severity. No significant statistical differences were found by grade classification. Moreover, salivary IL-1β and IL-6 exhibited significant positive correlations with several clinical measurements (PI, BOP, PPD, CAL), while IP-10 showed a statistical negative correlation with BOP, PPD, and CAL. These insights highlight the complexity of the periodontitis inflammatory network and the potential of cytokines as biomarkers for refined diagnostic and therapeutic strategies.

Analysis of Salivary Levels of IL-1β, IL17A, OPG and RANK-L in Periodontitis Using the 2017 Classification of Periodontal Diseases-An Exploratory Observational Study

Periodontitis is a chronic disease with a high overall prevalence. It involves a complex interplay between the immune-inflammatory pathways and biofilm changes, leading to periodontal attachment loss. The aims of this study were (i) to assess whether the salivary IL-1β, IL-17A, RANK-L and OPG levels have the potential to discriminate between the mild and severe periodontitis conditions; and (ii) to enable diagnostic/prognostic actions to differentiate between distinct levels of the disease. The analysis of the clinical parameters and the evaluation of the salivary immunomediators levels by means of a multiplex flow assay revealed a statistically significantly higher level of IL-1β in the periodontitis III/IV patients, as well as a higher level of RANK-L in the periodontitis III/IV and I/II patients, when compared to the healthy controls. Furthermore, the grade C periodontitis patients presented a significantly higher level of RANK-L compared to the grade B and grade A patients. In the grade C patients, IL-1β had a positive correlation with the PPD and CAL indices and RANK_L had a positive correlation with CAL. The evidence emerging from this study associates the salivary IL-1β and RANK-L levels with an advanced stage of periodontitis, stage III/IV, and with grade C, suggesting the possible cooperative action of both in the inflammatory and bone loss events. In addition to IL-1β, RANK-L could be considered a combined diagnostic biomarker for periodontitis.

Detection of soluble urokinase type plasminogen activator receptors in children with gingivitis and normal subjects

BACKGROUND

Gingivitis is a reversible condition; however, if left untreated, it progresses to periodontitis, which a serious infection that leads to bone destruction. Soluble urokinase-type plasminogen activator receptor (suPAR) measurement may be of value in the early assessment of gingivitis in children, thereby minimizing risk of tooth loss.

OBJECTIVES

In this observational study, we assessed salivary and serum concentrations of suPAR for the diagnosis of gingivitis and correlation of salivary suPAR with the periodontal clinical parameters.

METHODS

Ninety children participated in the study, with 20 healthy subjects as controls and 70 patients with gingivitis. The gingivitis group was divided into mild, moderate, and severe cases. According to the gingival index (GI), salivary and serum samples were analyzed for the suPAR and C-reactive protein levels using an enzyme-linked immunosorbent assay.

RESULTS

The salivary suPAR was significantly higher in patients with gingivitis (10.8 ± 2.9 ng/mL) than in the control group (7.0 ± 1.1 ng/mL) as P < 0.001. SuPAR was correlated with gingivitis severity. It was 7.7 ± 1.5 1 ng/mL in mild cases, 10.9 ± 1.2 ng/mL in moderate cases, and 14.4 ± 0.9 ng/mL in severe cases. The difference was significantly high (P < 0.001) between the groups; however, the difference between the mild cases and the control was nonsignificant as P < 0.066. The salivary suPAR was correlated with periodontal clinical parameters, which included GI and simple oral hygiene index (SOHI). Conversely the serum suPAR was not correlated with the salivary suPAR or the periodontal clinical parameters.

CONCLUSION

The results of the present study demonstrated that the salivary suPAR is increased in proportionate with the degree of severity of gingivitis in children. Moreover, salivary suPAR was correlated with the periodontal clinical parameters.

Relationship between Dynamics of TNF-α and Its Soluble Receptors in Saliva and Periodontal Health State

Soluble tumor necrosis factor receptors 1 and 2 (sTNF-R1 and sTNF-R2) are reported to protect against excessive TNF-α, a primary mediator of systemic responses to infection. This study aimed to investigate the levels of TNF-α, sTNF-R1, and sTNF-R2 in saliva and to verify whether their dynamics are associated with periodontal health. The study population comprised 28 adult patients. Probing pocket depth, clinical attachment level, and bleeding on probing were assessed, and periodontal inflamed surface area (PISA) was calculated. Stimulated saliva was collected before the oral examinations. The levels of TNF-α, sTNF-R1, sTNF-R2, and total protein (TP) in saliva samples were determined. There were significant positive correlations between TNF-α, sTNF-R1, and sTNF-R2 to TP (/TP) in stimulated saliva. Moreover, there were significant positive correlations between PISA and sTNF-R2/TP. Stepwise multiple regression analysis revealed that PISA was significantly associated with sTNF-R2/TP in saliva; however, TNF-α/TP was not significantly associated with PISA. In conclusion, this study demonstrates that significant relationships exist between the salivary levels of TNF-α and sTNF-R1, and that salivary sTNF-R2 is associated with the expansion of inflamed periodontal tissue.

Best practice recommendations for the measurement and interpretation of salivary proinflammatory cytokines in biobehavioral research

Despite the integration of salivary inflammatory cytokines into research across the biobehavioral, psychological, clinical, and health-related disciplines, there is little guidance regarding the biospecimen collection, handling, and storage practices that maximize the quality and validity of salivary cytokine data. Furthermore, associations between salivary cytokines and measures related to oral health are rarely assessed and accounted for in studies outside the oral health fields. To address these gaps, we examine the sensitivity of salivary interleukin-1β (IL-1β), IL-6, IL-8, and tumor necrosis factor-α (TNF-α) to changes in saliva sample collection technique and cold chain management procedures. Using subsets of saliva samples collected from 150 healthy adults, we measure salivary IL-1β, IL-6, IL-8, TNF-α, and other oral health-related indices (i.e., blood contamination [transferrin], and salivary matrixmallotprotienase-8). In addition to examining changes in cytokine levels associated with sample collection technique and cold chain management procedures, we assess relations between cytokine concentrations and levels of other oral health-related measures. We found that IL-1β, IL-6, and IL-8 were more robust to changes in sample collection and cold chain management procedures than TNF-α, and all cytokines were positively associated with other oral health-related measures. Based on our findings, we recommend analyte-specific guidance for measuring and interpreting salivary cytokine concentrations.

The familial trend of the local inflammatory response in periodontal disease

OBJECTIVES

The imbalanced host response in front of a dysbiotic biofilm is one of the major aspects of severe periodontitis, which also presents a strong familial aggregation related to the susceptibility factors transmission within family members. This study hypothesized that aggressive periodontitis (GAgP) patients and their descendants could present a similar trend of a local inflammatory response that is different from healthy controls.

METHODS

Fifteen GAgP subjects and their children and fifteen healthy subjects and their children were clinically assessed, and the concentration of interferon (IFN)-γ, interleukin (IL)-10, IL-17, IL-1β, IL-4, IL-6, IL-8, and tumor necrosis factor (TNF)-α was evaluated in the gingival fluid using the multiplexed bead immunoassay.

RESULTS

Children from the GAgP group presented lower IL-10 and IFN-γ subgingival concentration than Health children, despite no difference in the clinical parameters. GAgP parents showed a lower IFN-γ, IL-10, and IL-6 than healthy subjects. IL-10/IL-1β and IFN-γ/IL-4 ratios were reduced in GAgP dyads, suggesting a familial trend in the subgingival cytokine's profile. The cytokines correlated to the clinical data and were predictors of probing depth increase.

CONCLUSION

GAgP parents and their children presented a similar cytokine profile and an imbalance in the subgingival response characterized by decreased IFN-γ/IL-4 and IL10/IL-1β ratios.

A review of T helper 17 cell-related cytokines in serum and saliva in periodontitis

Periodontitis is a chronic inflammatory disease with a complex underlying immunopathology. Cytokines, as molecular mediators of inflammation, play a role in all stages of disease progression. T helper 17 (Th17) cells are thought to play a role in periodontitis. Th17 cell development and maintenance requires a pro-inflammatory cytokine milieu, with many of the cytokines implicated in the pathogenesis of periodontitis. Serum and saliva are easily accessible biofluids which can represent the systemic and local environment to promote the development of Th17 cells. Here we review human clinical studies that investigate IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40L and TNF-α in serum and saliva in periodontitis. We highlight their putative role in the pathogenesis of periodontitis and place them within a wider context of animal and other clinical studies.

Biomarkers of orthodontic tooth movement with fixed appliances and vibration appliance therapy: a pilot study

INTRODUCTION

The aim of this study was to investigate the effect of supplemental vibratory force on biomarkers of bone remodelling during orthodontic tooth movement, the rate of mandibular anterior alignment (RMAA), and compliance with a vibration device.

DESIGN, SETTINGS, AND PARTICIPANTS

Forty patients between the ages 15-35 undergoing fixed appliance treatment that presented to a university orthodontic clinic were randomly allocated to supplemental use of an intraoral vibrational device (n = 20, AcceleDent®) or fixed appliance only (n = 20). Salivary multiplex assay was completed to analyse the concentration of selected biomarkers of bone remodelling before treatment (T0) and at three following time points (T1, T2, T3), 4-6 weeks apart. Irregularity of the mandibular anterior teeth and compliance was assessed at the same trial time points. Data were analysed blindly on an intention-to-treat basis with descriptive statistics, Mann-Whitney U-test, Wilcoxon signed-rank test, and linear mixed effects regression modelling.

RESULTS

No difference in the changes in salivary biomarkers of bone remodelling and RMAA between groups at any time point over the trial duration was observed. No correlation was found between changes in irregularity and biomarker level from baseline to another time point. Lastly, there was no association between RMAA and compliance with the AcceleDent® device.

CONCLUSIONS

Supplemental vibratory force during orthodontic treatment with fixed appliances does not affect biomarkers of bone remodelling or the RMAA.

LIMITATIONS

The main limitation of the study was the small sample size and the large variability in the salivary biomarkers.

HARMS

No harms were observed during the duration of the trial.

PROTOCOL

The protocol was not published prior to trial commencement.

REGISTRATION

The study was registered in Clinical Trials.gov (NCT02119455) first posted on April 2014.

Autophagy, One of the Main Steps in Periodontitis Pathogenesis and Evolution

Periodontitis represents a complex inflammatory disease that compromises the integrity of the tooth-supporting tissue through the interaction of specific periodontal pathogens and the host's immune system. Experimental data help to outline the idea that the molecular way towards periodontitis initiation and progression presents four key steps: bacterial infection, inflammation, oxidative stress, and autophagy. The aim of this review is to outline the autophagy involvement in the pathogenesis and evolution of periodontitis from at least three points of view: periodontal pathogen invasion control, innate immune signaling pathways regulation and apoptosis inhibition in periodontal cells. The exact roles played by reactive oxygen species (ROS) inside the molecular mechanisms for autophagy initiation in periodontitis still require further investigation. However, clarifying the role and the mechanism of redox regulation of autophagy in the periodontitis context may be particularly beneficial for the elaboration of new therapeutic strategies.

Omega-3 Polyunsaturated Fatty Acids EPA and DHA as an Adjunct to Non-Surgical Treatment of Periodontitis: A Randomized Clinical Trial

Periodontitis is a chronic multifactorial inflammatory disease that leads to the loss of supportive tissues around the teeth with gradual deterioration of masticatory function and esthetics, resulting eventually in the decrease of the life quality. Host immune response triggered by bacterial biofilm is responsible for the chronic periodontal inflammation and ongoing tissue loss. Omega-3 polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have anti-inflammatory properties, thus may be used for the treatment of chronic inflammatory diseases. In this study, we aimed to evaluate the effect of dietary supplementation with omega-3 PUFA in the patients with stage III and IV periodontitis. Thirty otherwise healthy patients were treated with scaling and root planning (SRP). In the test group (n = 16), patients were additionally supplemented with 2.6 g of EPA and 1.8 g of DHA. In the control group (n = 14), patients received only SRP. Periodontal examination was performed at baseline and three months following initial therapy. Salivary samples were taken twice at baseline and at the end of the experiment. We found that there was a statistically significant reduction in the bleeding on probing (BOP) and improvement of clinical attachment loss (CAL) at three months in the test group compared to the control group. Moreover, a statistically significant higher percentage of closed pockets (probing depth ≤ 4 mm without BOP) was achieved in the test group vs. control group after three months of treatment. Accordingly, the levels of pro-inflammatory cytokines/chemokines interleukin (IL)-8 and IL-17 were markedly lower, while the level of anti-inflammatory IL-10 was significantly higher in the salivary samples of the patients supplemented with omega-3 PUFA at three months in comparison to the patients treated with SRP alone. Our findings demonstrate that dietary intervention with high-dose of omega-3 PUFA during non-surgical therapy may have potential benefits in the management of periodontitis.

T helper 17 cell-related cytokines in serum and saliva during management of periodontitis

AIM

T helper (Th)17 cells are implicated in the pathogenesis of periodontitis. This study investigated the effect of periodontal management on fifteen Th17-related cytokines in serum and saliva in periodontitis patients.

MATERIALS AND METHODS

Periodontal parameters, serum and saliva were collected from 40 healthy controls and 54 periodontitis subjects before treatment, and 3-, 6- and 12-months post-treatment. Cytokine concentrations of IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40L and TNF-α were determined by Luminex assay.

RESULTS

IL-1β, IL-6, sCD40L and TNF-α in serum, and IL-1β, IL-6, IL-25 and IL-31 in saliva were significantly higher at baseline compared to health and decreased with treatment. In contrast, serum IL-31 was significantly lower at baseline compared to health and increased with treatment. In addition, salivary IL-10, IL-17A, IL-17F, IL-23, IL-33, IFN-γ and TNF-α also displayed treatment-related reduction. Correlation networks showed that cytokines in saliva displayed a higher number of correlations compared to serum in periodontitis.

CONCLUSION

Treatment generally decreased cytokine concentrations except for serum IL-31 which showed a treatment-related increase. Serum cytokine concentrations may not be reflective of salivary cytokines. Saliva may be a better medium for cytokine detection compared to serum. Serum IL-31 and salivary IL-1β, IL-6, IL-10 and TNF-α were significant predictors for mean probing depth and may be potential biomarkers of interest in the pathogenesis of periodontitis.

Assessment of saliva and gingival crevicular fluid soluble urokinase plasminogen activator receptor (suPAR), galectin-1, and TNF-α levels in periodontal health and disease

OBJECTIVE

The aim of the study is to evaluate saliva and gingival crevicular fluid (GCF) levels of suPAR and galectin-1 in different periodontal health status and relationship between these molecules and TNF-α to understand the roles of these molecules in periodontal inflammation process.

BACKGROUND

Soluble urokinase plasminogen activator receptor (suPAR) has been described as a biological marker of inflammation and immunological activation. Galectin-1, a member of the galectin family, is an anti-inflammatory cytokine. However, to date, levels of these two molecules in periodontal health and disease have not been well documented.

METHODS

A total of 60 individuals, 20 with chronic periodontitis (group P), 20 with gingivitis (group G), and 20 with healthy periodontium (group H) were recruited for this study. Full-mouth clinical periodontal measurements were recorded in periodontal charts. GCF and whole saliva samples were collected to determine the levels of suPAR, galectin-1, and TNF-α in study groups using enzymelinked immunosorbent assay (ELISA) method.

RESULTS

The GCF total amount of suPAR, galectin-1, and TNF-α in GCF was similar in group P and G (P > .05). The GCF total amounts of these molecules in GCF were higher in the group G and P compared to the group H (P < .05), whereas the GCF concentrations of suPAR and galectin-1 were lower in the group G and P compared to the group H (P < .05).The saliva concentration of suPAR was significantly higher in group P compared to the group G and H (P < .05). It was also higher in the group G compared to the group H but there is no significant difference between the groups (P > .05). Salivary galectin-1 levels were similar in the study groups (P > .05).

CONCLUSION

Increased levels of GCF suPAR, galectin-1, and saliva suPAR in periodontal disease suggest that these molecules may play a role in the periodontal inflammation. suPAR and galectin-1 may be considered as potential biomarkers in periodontal disease.

Elevated levels of Interleukin (IL)-1β, IL-6, tumor necrosis factor-α, epidermal growth factor, and β2-microglobulin levels in gingival crevicular fluid during human Orthodontic tooth movement (OTM)

AIM

The aim of this study was to identify and quantify the various cytokines in human gingival crevicular fluid (GCF), and to investigate the changes in their levels during orthodontic tooth movement (OTM).

MATERIALS AND METHODS

A statistically significant no. of subjects (n = 10 and mean age = 15.6 years) were included in the study. A maxillary cuspid of each subject having one treatment for distal orthodontic tooth movement served as the experimental tooth, whereas the contralateral cuspids were used as controls. Gingival crevicular fluid (GCF) around the experimental and the two control teeth was collected from each subject immediately before activation, and at 1, 24, and 168 hours after the initiation of tooth movement.

RESULT

ELISAs were used to determine cytokine levels. The concentrations of interleukin (IL)-1lβ, IL-6, tumor necrosis factor-α, epidermal growth factor, and β2-microglobulin were significantly higher in the experimental group than in the controls at 24 hr after the experiment was initiated. All the cytokines remained at baseline levels throughout the experiment for the control groups.

CONCLUSION

Since all cytokines in GCF play an important role in the bone remodelling processes in vivo, the present results indicate that the changes in cytokines in GCF are associated with OTM.

Tumor Necrosis Factor-alpha in Gingival Crevicular Fluid as a Diagnostic Marker for Periodontal Diseases: A Systematic Review

OBJECTIVES

The aim of this systematic review was to evaluate human gingival crevicular fluid (GCF) tumor necrosis factor-alpha (TNF-α) as a potential biomarker for diagnosis of periodontal disease (International prospective register of systematic reviews [PROSPERO] number: CRD42015020199).

METHODS

An electronic search for TNF-α in human GCF was conducted until May 17, 2018. Data from systemically healthy patients with healthy periodontium or periodontal disease were incorporated. Risk bias was assessed by Newcastle-Ottawa Scale for case-control studies and Jadad scale for clinical trials.

RESULTS

Twenty-six studies were included (12 case-control studies, 7 clinical trials, and 7 randomized controlled trials). Most case-control studies showed increased TNF-α concentration in GCF of patients with periodontal disease. The clinical trials and randomized controlled trials demonstrated no consistent modification of TNF-α level after periodontal intervention.

CONCLUSION

The present data support the use of TNF-α in GCF as a potential biomarker for diagnosis of periodontal disease but not to monitor the healing after therapy.

Cytokine profile in gingival crevicular fluid and plasma of patients with aggressive periodontitis

OBJECTIVE

This study aimed to determine the content of cytokines in gingival crevicular fluid (GCF) as well as in plasma of Sudanese patients with aggressive periodontitis (AgP) and healthy controls (HC).

MATERIALS AND METHODS

Nineteen AgP patients and 19 HC were included. The mean probing pocket depth and clinical attachment level of the GCF sampled sites in patients were both ≥5 mm. The GCF and plasma levels of 27 cytokines were determined using 27-multiplex fluorescent bead-based immunoassays. Ratios were calculated among cytokines of the T-helper cell subsets Th1 and Th2. Descriptive statistics, the Mann-Whitney U-test and Spearman's rho rank correlation coefficient analysis were used.

RESULTS

Interferon-γ was the only cytokine found in significantly lower levels in GCF of patients compared with HC. Levels of interleukin (IL)-10, IL-13, IL-1Ra, monocyte chemoattractant protein-1 (MCP-1), regulated on activation normal T-cell expressed and secreted (RANTES), granulocyte-colony-stimulating factor (G-CSF), and granulocyte-macrophage-CSF (GM-CSF) were significantly lower in plasma of AgP compared with HC. The ratios of Th1:Th2 in GCF and Treg:Th17 in plasma were significantly lower in AgP.

CONCLUSIONS

The lower levels of cytokines detected systemically in plasma of AgP patients may have an impact on the immune response. The lower ratio of Th1:Th2 cytokines in GCF samples of AgP patients suggests a role for Th2 at the local site of disease.

Periodontal Disease-Induced Atherosclerosis and Oxidative Stress

Periodontal disease is a highly prevalent disorder affecting up to 80% of the global population. Recent epidemiological studies have shown an association between periodontal disease and cardiovascular disease, as oxidative stress plays an important role in chronic inflammatory diseases such as periodontal disease and cardiovascular disease. In this review, we focus on the mechanisms by which periodontopathic bacteria cause chronic inflammation through the enhancement of oxidative stress and accelerate cardiovascular disease. Furthermore, we comment on the antioxidative activity of catechin in atherosclerosis accelerated by periodontitis.

Inflammatory Mediators of Leprosy Reactional Episodes and Dental Infections: A Systematic Review

Reactional episodes in leprosy are a result of complex interactions between the immune system, Mycobacterium leprae, and predisposing factors, including dental infections. To determine the main inflammatory mediators in the immunopathological process of dental infections and leprosy reactions, we conducted a systematic review of primary literature published between 1996 and 2013. A three-stage literature search was performed (Stage I, "leprosy reactions" and "inflammatory mediators"; Stage II, "dental infections" and "inflammatory mediators"; and Stage III, "leprosy reactions," "dental infections," and "inflammatory mediators"). Of the 911 eligible publications, 10 were selected in Stage I, 68 in Stage II, and 1 in Stage III. Of the 27 studied inflammatory mediators, the main proinflammatory mediators were IL-6, IFN-γ, TNF-α, IL-1β, and IL-17; the main anti-inflammatory mediators were IL-10 and IL-4. Serum IL-6 and TNF-α concentrations were significant during periodontal and reactional lesion evolution; IFN-γ and IL-1β were associated with types 1 and 2 reactions and chronic periodontal disease. The proinflammatory mediators in dental infections and leprosy reactions, especially IL-6 and TNF-α, were similar across studies, regardless of the laboratory technique and sample type. IFN-γ and IL-1β were significant for leprosy reactions and periodontal diseases. This pattern was maintained in serum.

Green tea polyphenol epigallocatechin-3-gallate and cranberry proanthocyanidins act in synergy with cathelicidin (LL-37) to reduce the LPS-induced inflammatory response in a three-dimensional co-culture model of gingival epithelial cells and fibroblasts

OBJECTIVES

The human antimicrobial peptide cathelicidin (LL-37) possesses anti-inflammatory properties that may contribute to attenuating the inflammatory process associated with chronic periodontitis. Plant polyphenols, including those from cranberry and green tea, have been reported to reduce inflammatory cytokine secretion by host cells. In the present study, we hypothesized that A-type cranberry proanthocyanidins (AC-PACs) and green tea epigallocatechin-3-gallate (EGCG) act in synergy with LL-37 to reduce the secretion of inflammatory mediators by oral mucosal cells.

METHODS

A three-dimensional (3D) co-culture model of gingival epithelial cells and fibroblasts treated with non-cytotoxic concentrations of AC-PACs (25 and 50 μg/ml), EGCG (1 and 5 μg/ml), and LL-37 (0.1 and 0.2 μM) individually and in combination (AC-PACs+LL-37 and EGCG+LL-37) were stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS). Multiplex ELISA assays were used to quantify the secretion of 54 host factors, including chemokines, cytokines, growth factors, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs).

RESULTS

LL-37, AC-PACs, and EGCG, individually or in combination, had no effect on the regulation of MMP and TIMP secretion but inhibited the secretion of several cytokines. AC-PACs and LL-37 acted in synergy to reduce the secretion of CXC-chemokine ligand 1 (GRO-α), granulocyte colony-stimulating factor (G-CSF), and interleukin-6 (IL-6), and had an additive effect on reducing the secretion of interleukin-8 (IL-8), interferon-γ inducible protein 10 (IP-10), and monocyte chemoattractant protein-1 (MCP-1) in response to LPS stimulation. EGCG and LL-37 acted in synergy to reduce the secretion of GRO-α, G-CSF, IL-6, IL-8, and IP-10, and had an additive effect on MCP-1 secretion.

CONCLUSION

The combination of LL-37 and natural polyphenols from cranberry and green tea acted in synergy to reduce the secretion of several cytokines by an LPS-stimulated 3D co-culture model of oral mucosal cells. Such combinations show promising results as potential adjunctive therapies for treating inflammatory periodontitis.

Effect of orthodontic forces on cytokine and receptor levels in gingival crevicular fluid: a systematic review

This systematic review aimed to generate evidence on role of potent markers of inflammation [cytokines, chemokines, their associated receptors and antagonists] following the application of orthodontic forces. Subsequent to registration with PROSPERO, literature search followed a predetermined search strategy to key databases along with hand search (HS). Seventy-seven articles from PubMed (P), 637 from Scopus (S), 51 from Embase (E), and 3 from hand search (HS) were identified. A total of 39 articles were shortlisted that met strict inclusion and exclusion criteria and quality assessment. Each study was evaluated for participant characteristics, study design, oral hygiene regimen, and gingival crevicular fluid (GCF) handling. Among these studies, biomarkers in the order of frequency were interleukin (IL)-1β (N = 21), tumor necrosis factor (TNF)-α (N = 10), IL-8,IL-6(N=8), receptor activator of nuclear factor kappa-B ligand (RANKL) (N = 7), monocyte chemoattractant protein (MCP)-1 (N = 3), IL-2 (N=4), IL-4, IL-10, RANTES (N = 2), IL-1, IL-5, IL-1α, IP-10, osteopontin (OPN) (N = 1) and receptors and their antagonists in the order of osteoprotegerin (OPG) (N = 8), IL-1RA (N = 5), and RANK (N = 1). Results revealed an immediate release of inflammatory bone-resorptive mediators, IL-1β and TNF-α, where IL-1β increased as early as 1 min to 1 h reaching peak at 24 h while TNF-α increased at 1 h or 1 day. This was accompanied by a fall in bone-protective mediator (OPG) levels at 1 h and 24 h after orthodontic force application. Continuous forces were accompanied by a decrease in mediator levels after attaining peak levels (most commonly at 24 h) while repeated activations in interrupted force upregulated their secretion. Significant correlations of IL-1β levels with pain intensity, rate of orthodontic tooth movement (OTM) and of activity index (AI) (IL-1β/IL-1RA) with velocity of tooth movement and growth status of individuals have also been deduced. A greater AI and RANKL/OPG ratio was seen in juveniles as compared to adults or non-growers that were associated with faster rate of OTM in juveniles. None of the studies addressed the effect of estrous cycle in female subjects. Lack of homogeneity in several parameters calls for a better controlled research on the biology of OTM.

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

OBJECTIVE

Salivary biomarkers have been recently useful of periodontal disease, which is also risk factor of atherosclerosis. However, there are few studies of the association between salivary inflammatory cytokines and carotid atherosclerosis. We aimed to clarify the association between salivary inflammatory cytokines and periodontal disease and carotid atherosclerosis in a general urban population.

METHODS

We studied 608 Japanese men and women (mean age: 65.4 years) in the Suita study. Carotid atherosclerosis was evaluated by high-resolution ultrasonography with atherosclerotic indexes of intima-media thickness (IMT). Periodontal status was evaluated by the Community Periodontal Index (CPI). Salivary levels of interleukin-1β, interleukin-6, tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2) were measured by enzyme linked immunosorbent assay. The risks of carotid atherosclerosis (≥75th percentiles of mean- [0.88 mm] and Max-IMT [1.50 mm]) according to the quartiles of salivary inflammatory cytokines were compared using of adjusted-logistic regression models.

RESULTS AND CONCLUSION

All salivary inflammatory cytokines were positively associated with CPI. The adjusted odds ratios for carotid atherosclerosis of mean-IMT in the highest quartile of interleukin-6 and TNF-α were higher than those in the lowest quartiles (OR = 2.32 and 2.88; 95% confidence intervals = 1.19-4.51 and 1.51-5.49, respectively). The adjusted odds ratio for carotid atherosclerosis of mean-IMT in the highest quartile of PGE2 was greater than those in the lowest quartile in women (OR = 2.78; 95% confidence intervals = 1.11-6.95). In conclusion, higher levels of salivary inflammatory cytokines were associated with both periodontal disease and carotid atherosclerosis. Selected salivary inflammatory cytokines may be useful screening markers for periodontal disease and carotid atherosclerosis.

Tumor necrosis factor-α induces interleukin-34 expression through nuclear factor‑κB activation in MC3T3-E1 osteoblastic cells

Osteoblasts produce various types of cytokines under pathological conditions and control osteoclast differentiation. Tumor necrosis factor-α (TNF-α) has been demonstrated to exert complex effects in osteoblasts under local inflammatory conditions, including in periodontal and periapical diseases. Interleukin-34 (IL-34) has been recently identified as a novel regulatory factor for the differentiation and function of osteoclasts. The present study provides the first evidence, to the best of our knowledge, that the expression of IL-34 is induced by TNF-α through nuclear factor-κB (NF-κB) activation in MC3T3-E1 osteoblastic cells. TNF-α induced IL-34 expression in a dose- and time-dependent manner. Immunocytochemistry with an NF-κB antibody demonstrated that NF-κB was mainly localized in the cytoplasm of the untreated MC3T3-E1 cells. Rapid translocation of NF-κB from the cytoplasm to the nucleus was observed in the cells treated with TNF-α for 15 min. Translocation and transcriptional activity of NF-κB were also determined by western blotting and a luciferase reporter assay, respectively. Pretreatment with 100 μM CAPE, an inhibitor of NF-κB, significantly inhibited TNF-α-induced IL-34 expression. These results indicate that TNF-α induces IL-34 expression via NF-κB in osteoblasts.

Activation of NLRP3 and AIM2 inflammasomes by Porphyromonas gingivalis infection

Porphyromonas gingivalis, a major periodontopathogen, is involved in the pathogenesis of periodontitis. Interleukin-1β (IL-1β), a proinflammatory cytokine, regulates innate immune responses and is critical for the host defense against bacterial infection. However, excessive IL-1β is linked to periodontal destruction. IL-1β synthesis, maturation, and secretion are tightly regulated by Toll-like receptor (TLR) signaling and inflammasome activation. We found much higher levels of inflammasome components in the gingival tissues from patients with chronic periodontitis than in those from healthy controls. To investigate the molecular mechanisms by which P. gingivalis infection causes IL-1β secretion, we examined the characteristics of P. gingivalis-induced signaling in differentiated THP-1 cells. We found that P. gingivalis induces IL-1β secretion and inflammatory cell death via caspase-1 activation. We also found that P. gingivalis-induced IL-1β secretion and pyroptic cell death required both NLRP3 and AIM2 inflammasome activation. The activation of the NLRP3 inflammasome was mediated by ATP release, the P2X7 receptor, and lysosomal damage. In addition, we found that the priming signal via TLR2 and TLR4 activation precedes P. gingivalis-induced IL-1β release. Our study provides novel insight into the innate immune response against P. gingivalis infection which could potentially be used for the prevention and therapy of periodontitis.