LPS-induced inflammatory response after therapy of aggressive periodontitis

Grade C Molar-Incisor Pattern Periodontitis in Young Adults: What Have We Learned So Far?

Grade C molar-incisor pattern periodontitis (C-MIP) is a disease that affects specific teeth with an early onset and aggressive progression. It occurs in systemically healthy patients, mostly African descendants, at an early age, with familial involvement, minimal biofilm accumulation, and minor inflammation. Severe and rapidly progressive bone loss is observed around the first molars and incisors. This clinical condition has been usually diagnosed in children and young adults with permanent dentition under 30 years of age. However, this disease can also affect the primary dentition, which is not as frequently discussed in the literature. Radiographic records have shown that most patients diagnosed in the permanent dentition already presented disease signs in the primary dentition. A hyperresponsive immunological profile is observed in local (gingival crevicular fluid-GCF) and systemic environments. Siblings have also displayed a heightened inflammatory profile even without clinical signs of disease. A. actinomycetemcomitans has been classified as a key pathogen in C-MIP in both dentitions. Scaling and root planning associated with systemic antibiotics is the current gold standard to treat C-MIP, leading to GCF biomarker reduction, some systemic inflammatory response modulation and microbiome profile changes to a healthy-site profile. Further studies should focus on other possible disease-contributing risk factors.

Dental Stem Cells and Lipopolysaccharides: A Concise Review

Dental tissue stem cells (DTSCs) are well known for their multipotent capacity and regenerative potential. They also play an important role in the immune response of inflammatory processes derived from caries lesions, periodontitis, and gingivitis. These oral diseases are triggered by toxins known as lipopolysaccharides (LPS) produced by gram-negative bacteria. LPS present molecular patterns associated with pathogens and are recognized by Toll-like receptors (TLRs) in dental stem cells. In this review, we describe the effect of LPS on the biological behavior of DTSCs. We also focus on the molecular sensors, signaling pathways, and emerging players participating in the interaction of DTSCs with lipopolysaccharides. Although the scientific advances generated provide an understanding of the immunomodulatory potential of DTSCs, there are still new reflections to explore with regard to their clinical application in the treatment of oral inflammatory diseases.

Ageing and Inflammation: What Happens in Periodontium?

Periodontitis is a chronic inflammatory disease with a high incidence and severity in the elderly population, making it a significant public health concern. Ageing is a primary risk factor for the development of periodontitis, exacerbating alveolar bone loss and leading to tooth loss in the geriatric population. Despite extensive research, the precise molecular mechanisms underlying the relationship between ageing and periodontitis remain elusive. Understanding the intricate mechanisms that connect ageing and inflammation may help reveal new therapeutic targets and provide valuable options to tackle the challenges encountered by the rapidly expanding global ageing population. In this review, we highlight the latest scientific breakthroughs in the pathways by which inflammaging mediates the decline in periodontal function and triggers the onset of periodontitis. We also provide a comprehensive overview of the latest findings and discuss potential avenues for future research in this critical area of investigation.

Treatment of Periodontitis Affecting Human Primary Teeth-A Systematic Review

The aim of this systematic review is to report the treatment options (Intervention) and outcomes (O) for primary teeth affected by periodontitis (Population) and if the treatment of primary teeth can prevent the spread of periodontitis to permanent teeth (Outcomes). The following databases were searched for papers published before December 2022: PubMed, Embase, Web of Science, and Ebscohost. Studies on children affected by periodontitis involving the primary teeth were included and those on children who presented with periodontitis as a manifestation of systemic disease were excluded. Narrative synthesis and methodological quality assessments were performed for the included studies. Three interventional studies (without a control group) that evaluated treatments involving scaling and root planing (SRP with antibiotics) and extraction were included (total n = 60 patients). Additionally, twelve case reports/case series articles (n = 19 patients) were identified. The diagnoses ranged from aggressive periodontitis to juvenile periodontitis and pre-pubertal periodontitis. Based on a limited number of published studies, it was found that the early treatment of periodontitis affecting the primary teeth using SRP and systemic antibiotics resulted in favorable improvements in PD and CAL. Limited evidence suggests that SRP and the extraction of the primary teeth involved have the potential to prevent periodontitis affecting permanent teeth. Future trials are required to standardize the treatment protocols and to confirm these findings.

Astragaloside reduces toxic effect of periodontal ligament fibroblasts induced by lipopolysaccharide

Periodontitis is a non-specific and chronic disease which is highly prevalent, resulting in inflammation and destruction of periodontal tissues. This study aims to explore the effect and mechanism of astragaloside on periodontitis. We used CCK-8, Western Blot, qPCR and flow cytometry to analyze cell viability, related protein and mRNA expression, and cell apoptosis. We found that AST could promote cell proliferation and reduce apoptosis induced by LPS. Besides, AST could alleviate the increased expression of COX-2 and ICAM-1 induced by LPS. MiR-26b-3P specifically targeted the 3' UTR of ICAM-1. These results indicate that AST reduces toxic effect of human periodontal ligament cells through regulating miR-26b-3P/ICAM-1, thus highlighting its protective role in periodontitis.

Pattern of grade C molar-incisor pattern periodontitis in families

BACKGROUND

The aim of this study was to determine the clinical and inflammatory response patterns for individual siblings diagnosed with grade C molar-incisor pattern periodontitis (C-MIP) and between the related siblings within families.

METHODS

Sixty-nine siblings within 28 families with moderate-to-severe C-MIP were included. Clinical parameters were evaluated for symmetry regarding the affected type of teeth, side and/or arch, and bone loss pattern. The protein concentrations from in vitro whole blood cultures for 14 different lipopolysaccharide-stimulated inflammatory markers were correlated with the extent and severity of disease, within an individual sibling and among siblings within a family.

RESULTS

A similar disease pattern was observed among all siblings and within families. The most common teeth affected were first molars and incisors or first molars only within the permanent dentition and only molars within the primary dentition (p < 0.001). Symmetry involving molars was higher than in incisors in siblings, regardless of arch or side affected (p = 0.020). Arc-shape/vertical bone defects were the most common (p = 0.006) and higher symmetry was found for these defects in the permanent dentition (p = 0.005). Positive correlations were found between age, clinical attachment loss, and percent affected sites with several inflammatory markers. The inflammatory responses for several inflammatory markers were correlated within and among families (p < 0.050). Specifically, the intraclass correlation coefficient within families was highest (>0.5) for interleukin (IL)-8, IL-6, and IL-10.

CONCLUSIONS

Families with C-MIP presented similar patterns of disease. The level of an inflammatory response to bacteria seemed to play a role in the extent and severity of this disease, exemplified by the high degree of correlation in these families.

Wnt Signaling Activation in Gingival Epithelial Cells and Macrophages of Experimental Periodontitis

Objective: Wingless/integrated (Wnt) signaling plays critical roles in maintaining environmental homeostasis and is also involved in the pathogenesis of inflammatory diseases. However, its role in macrophages during periodontitis is not well understood. The present study aims to investigate the interaction between Wnt signaling and macrophages in the context of periodontitis. Methods: Experimental periodontitis was induced in C57/BL6 mice using a Porphyromonas gingivalis (P.g)-associated ligature for 14 days. Immunohistochemistry was performed to study the expression of the pro-inflammatory cytokine tumor necrosis factor (TNF-α), the stabilization of β-catenin, and the macrophage marker F4/80 in the periodontal tissues. The effect of Wnt signaling on TNF-α was examined using Western blot analysis in Raw 264.7 murine macrophages stimulated by Wnt3a-conditioned medium, with or without Wnt3a antibody neutralization, and compared with primary cultured gingival epithelial cells (GECs). The effect of P.g lipopolysaccharide (LPS) on Wnt signaling was assessed by analyzing key components of the Wnt signaling pathway, including the activity of low-density lipoprotein receptor-related protein (LRP) 6 and nuclear accumulation of β-catenin in GEC and Raw 264.7 cells. Results: Over-expressions of TNF-α and activated β-catenin were presented in the macrophages in the gingiva from mice with P.g-associated ligature-induced periodontitis. The expression patterns of TNF-α and activated β-catenin were consistent with the expression of F4/80. In Raw 264.7 cells, activation of the Wnt signaling pathway led to an increase in TNF-α, but this effect was not observed in GEC. Additionally, treatment with LPS induced β-catenin accumulation and LRP6 activation in Raw 264.7 cells, which were blocked by the addition of Dickkopf-1(DKK1). Conclusions: Wnt signaling was aberrantly activated in the macrophages in experimental periodontitis. The activation of Wnt signaling in the macrophages may play a pro-inflammatory role in periodontitis. Targeting specific signaling pathways, such as the Wnt pathway, may hold promise for developing novel therapeutic interventions for periodontitis.

Impact of Treatment on Host Responses in Young Individuals with Periodontitis

Grade C periodontitis in young individuals is characterized by severe/rapid periodontal destruction, usually early onset, in systemically healthy individuals. An individual's host response, triggered by a dysbiotic subgingival biofilm, has been reported as a contributor to the tissue destruction, although mechanisms of this response and contributions to such disease remain poorly understood. Nonsurgical treatment has resulted in positive clinical responses for both localized (now molar-incisor pattern) and generalized forms of grade C periodontitis, especially when adjunctive systemic antibiotics are used. Nonsurgical treatment may also affect host responses, although mechanisms leading to significant changes in this response remain unclear. Significant effects on inflammatory response to antigens/bacteria have been described posttreatment, but evidence for long-term effects remains limited. Nonsurgical treatment in these individuals may also modulate a variety of host markers in serum/plasma and gingival crevicular fluid along with clinical parameter improvements. The impact of other adjuncts to nonsurgical treatment focusing on controlling exacerbated immunoinflammatory responses needs to be further explored in grade C periodontitis in young individuals. Recent evidence suggests that nonsurgical treatment with adjunctive laser therapy may modulate host and microbial responses in those subjects, at least in the short term. Available evidence, while very heterogeneous (including variations in disease definition and study designs), does not provide clear conclusions on this topic yet provides important insights for future studies. In this review, studies within the past decade evaluating the impact of nonsurgical treatment on systemic/local host responses in young individuals with grade C periodontitis, as well as long-term clinical responses posttreatment, will be critically appraised and discussed.

TNFα, IL-6, miR-103a-3p, miR-423-5p, miR-23a-3p, miR-15a-5p and miR-223-3p in the crevicular fluid of periodontopathic patients correlate with each other and at different stages of the disease

Periodontitis is one of the main frequent intraoral diseases. Pathogenesis triggers are the immune responses with pro-inflammatory cytokines production and non-coding RNAs expression. The purpose of the present study was to evaluate the involvement of selected miRNAs in various stages of periodontitis and their relationship with the levels of inflammatory mediators in gingival crevicular fluid (GCF). For this study, 36 subjects (21 with periodontal disease, 15 healthy controls) were selected with an age mean of 59.1 ± 3.7 years. Clinical parameters included plaque index, gingival index, sulcus bleeding index, pocket depth, and clinical attachment level. The GCF samples were taken using capillary paper. The levels of miRNAs in GCF were estimated using a Real-Time PCR and TNFα and IL-6 levels were assessed by enzyme-linked immunosorbent assay (ELISA). The results indicated that the miRNA-103a-3p, miRNA-23a-3p, miRNA-15a-5p, and miRNA-223-3p were significantly upregulated with respect to healthy controls. Significant differences were observed for miRNA-23a-3p, miRNA-103a-3p and miRNA-423-5p levels in accord with the disease stages. Inflammatory mediators evaluated in GCF correlate well with the clinical parameters and the severity of the periodontal disease. miRNAs can represent biomarkers of disease stage and can be investigated as a possible therapeutic target, as well as levels of TNFα and IL-6 may drive the disease progression by acting as prognostic markers.

Electrospun Nanofibers for Periodontal Treatment: A Recent Progress

Periodontitis is a major threat to oral health, prompting scientists to continuously study new treatment techniques. The nanofibrous membrane prepared via electrospinning has a large specific surface area and high porosity. On the one hand, electrospun nanofibers can improve the absorption capacity of proteins and promote the expression of specific genes. On the other hand, they can improve cell adhesion properties and prevent fibroblasts from passing through the barrier membrane. Therefore, electrospinning has unique advantages in periodontal treatment. At present, many oral nanofibrous membranes with antibacterial, anti-inflammatory, and tissue regeneration properties have been prepared for periodontal treatment. First, this paper introduces the electrospinning process. Then, the commonly used polymers of electrospun nanofibrous membranes for treating periodontitis are summarized. Finally, different types of nanofibrous membranes prepared via electrospinning for periodontal treatment are presented, and the future evolution of electrospinning to treat periodontitis is described.

Smoking negatively impacts the clinical, microbiological, and immunological treatment response of young adults with Grade C periodontitis

OBJECTIVE

This study aimed to investigate the influence of smoking on clinical, microbiological and immunological parameters in young adult with stage III-IV Grade C periodontitis after full-mouth ultrasonic debridement (FMUD) associated with Amoxicillin and Metronidazole (AMX + MTZ), comparing smokers (PerioC-Y-Smk) with non-smokers (PerioC-Y-NSmk).

MATERIALS AND METHODS

Fifteen PerioC-Y-NSmk and 14 PerioC-Y-Smk patients underwent FMUD associated with AMX + MTZ for 10 days. All parameters were collected at baseline and 3 and 6 months after treatment. Plaque index (PI), bleeding on probing (BoP), probing depth (PD), clinical attachment level (CAL)- the primary variable-, and gingival recession (GR) were clinically assessed. The impact of PI on CAL change at 6-month was verified by a regression analysis. Samples of the subgingival biofilm was collected for detection of levels of Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Porphyromonas gingivalis (P.gingivalis), Tannerella forsythia (T. forsythia), and Fusobacterium nucleatum ssp (F. nucleatum), and were analyzed by real-time qPCR; gingival crevicular fluid was collected for detection of levels of interleukin (IL)-1β, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ, which were analyzed using an enzyme immunoassay.

RESULTS

PerioC-Y-Smk had significantly higher PI, BOP, and GR at baseline compared to non-smokers (p < .05). PerioC-Y-Smk presented higher PD, CAL, and GR at 3 and 6 months (p < .05) compared with PerioC-Y-NSmk in the same periods; PI negatively affected CAL gain in PerioC-Y-NSmk at 6-month follow-up (p = .052) and did not impact on clinical response in PerioC-Y-Smk (p = .882). Lower levels of IFN-γ, IL1-β, and IL-4 were observed at 3 months in the PerioC-Y-NSmk (p < .05) compared with PerioC-Y-Smk. Lower proportions of P. gingivalis were observed in PerioC-Y-NSmk at baseline and at 3 months (p < .05) and lower proportions of F. nucleatum were observed at 6 months, in the PerioC-Y-NSmk (p < .05).

CONCLUSIONS

PerioC-Y-Smk presents an unfavorable clinical, microbiological, and immunological response after 3 and 6 months after FMUD associated with AMX + MTZ.

CLINICAL RELEVANCE

Smoking worsens periodontal condition of young treated adults presenting stage III/IV Grade C periodontitis.

LncRNA OIP5-AS1 inhibits the lipopolysaccharide-induced inflammatory response and promotes osteogenic differentiation of human periodontal ligament cells by sponging miR-92a-3p

Periodontitis is a chronic infectious disease that affects the oral health of adults. Long non-coding RNA OIP5 antisense RNA 1 (OIP5-AS1) has been reported to downregulated in the periodontal tissue of patients with periodontitis. Therefore, the study sought to look at the possible functions of OIP5-AS1 in periodontitis and the associated underlying mechanisms. In the present study, the expression level of OIP5-AS1 and microRNA-92a-3p were analyzed using reverse transcription-quantitative PCR. The levels of osteogenic proteins were determined using western blotting and inflammatory cytokines and oxidative stress were also examined. The proliferation of human periodontal ligament stem cells (hPDLSCs) was evaluated using MTT assays. Assay of osteogenic differentiation was undertaken by means of Alkaline phosphatase staining. The possible association between OIP5-AS1 and miR-92a-3p was determined applying dual-luciferase reporter assays and verified by RNA immunoprecipitation assay. We found that OIP5-AS1 was expressed at low levels in lipopolysaccharide (LPS)-stimulated hPDLSCs. OIP5-AS1 overexpression promoted proliferation and osteogenic differentiation ability and reduced LPS-induced inflammation in hPDLSCs. Furthermore, OIP5-AS1 directly targeted and reduced miR-92a-3p expression. The overexpression of miR-92a-3p partly abolished the effects of OIP5-AS1 on LPS-induced cell proliferation and osteogenic differentiation as well as inflammation in hPDLSCs. Collectively, the results indicated that OIP5-AS1 overexpression inhibited the LPS-induced inflammatory response and promoted the osteogenic differentiation of hPDLSCs by sponging miR-92a-3p. Thus, OIP5-AS1 is probably an essential objective for research during periodontitis treatment.

PAMPs and DAMPs as the Bridge Between Periodontitis and Atherosclerosis: The Potential Therapeutic Targets

Atherosclerosis is a chronic artery disease characterized by plaque formation and vascular inflammation, eventually leading to myocardial infarction and stroke. Innate immunity plays an irreplaceable role in the vascular inflammatory response triggered by chronic infection. Periodontitis is a common chronic disorder that involves oral microbe-related inflammatory bone loss and local destruction of the periodontal ligament and is a risk factor for atherosclerosis. Periodontal pathogens contain numerous pathogen-associated molecular patterns (PAMPs) such as lipopolysaccharide, CpG DNA, and Peptidoglycan, that initiate the inflammatory response of the innate immunity depending on the recognition of pattern-recognition receptors (PRRs) of host cells. The immune-inflammatory response and destruction of the periodontal tissue will produce a large number of damage-associated molecular patterns (DAMPs) such as neutrophil extracellular traps (NETs), high mobility group box 1 (HMGB1), alarmins (S100 protein), and which can further affect the progression of atherosclerosis. Molecular patterns have recently become the therapeutic targets for inflammatory disease, including blocking the interaction between molecular patterns and PRRs and controlling the related signal transduction pathway. This review summarized the research progress of some representative PAMPs and DAMPs as the molecular pathological mechanism bridging periodontitis and atherosclerosis. We also discussed possible ways to prevent serious cardiovascular events in patients with periodontitis and atherosclerosis by targeting molecular patterns.

METTL3 regulates LPS-induced inflammatory response via the NOD1 signaling pathway

N⁶-methyladenosine (m⁶A) is a prevalent mRNA modification that plays a crucial function in multiple biological processes. Methyltransferase-like 3 (METTL3), an m⁶A methyltransferase, is essential for the m⁶A modification. Recently, the effect of METTL3 on the immune response has been reported. However, the effect is unclear, and the results are contradictory. In the present study, the total m⁶A and the expression of METTL3 decreased in LPS-stimulated macrophages. METTL3 knockdown significantly upregulated expression of proinflammatory cytokines, including TNF-α, IL-6 and NO. RNA sequencing analysis showed that the upregulated genes were enriched in inflammation-related signaling pathways and that the NOD-like receptor signaling pathway might be the target molecules of METTL3. METTL3 depletion resulted in upregulation of the NOD1 pathway without impacting NOD2. Moreover, the increase in proinflammatory cytokines induced by METTL3 knockdown was reversed by blocking the NOD1 pathway using specific inhibitors. Mechanistically, METTL3 knockdown promoted the mRNA expression and stability of NOD1 and RIPK2, and the same results were detected in m⁶A-binding protein YTHDF1- or YTHDF2-silenced cells. All findings suggested that METTL3 depletion inhibits the degradation of NOD1 and RIPK2 mRNA mediated by YTHDF1 and YTHDF2, which upregulate the NOD1 pathway and subsequently promote the LPS-induced inflammatory response in macrophages.

Blood Biomarkers and Serologic Immunological Profiles Related to Periodontitis in Abdominal Aortic Aneurysm Patients

Background

Periodontitis is a chronic inflammatory gum disease associated with systemic diseases such as cardiovascular diseases.

Aim

To investigate the association of systemic blood biomarkers, C-reactive protein (CRP), levels of lipopolysaccharide (LPS), and IgG levels against periodontal pathogens Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) with the stability, based on the aortic diameter, the growth rate and the eligibility for surgical intervention, of patients with abdominal aortic aneurysm (AAA).

Methods

Patients with stable AAA (n = 30) and unstable AAA (n = 31) were recruited. The anti-A. actinomycetemcomitans and anti-P. gingivalis IgG levels were analyzed by ELISA, the LPS analysis was performed by using the limulus amebocyte lysate (LAL) test, and plasma levels of CRP were determined using an immune turbidimetric method. The association between these blood systemic biomarkers, AAA features, periodontal clinical parameters and oral microbial profiles were explored. Regression models were used to test the relationship between variables.

Results

The presence of antibodies against Pg and Aa, LPS and high CRP concentrations were found in all AAA patients. The IgG levels were similar in patients with stable and unstable AAA (both for Aa and Pg). Among investigated blood biomarkers, only CRP was associated with AAA stability. The amount of LPS in saliva, supra, and subgingival plaque were significantly associated with the systemic LPS (p <0.05).

Conclusions

This post-hoc study emphasizes the presence of antibodies against Pg and Aa, LPS and high CRP concentrations in all AAA patients. The presence of Pg in saliva and subgingival plaque was significantly associated with the blood LPS levels. For further studies investigating periodontitis and systemic diseases, specific predictive blood biomarkers should be considered instead of the use of antibodies alone.

Inhibition of nuclear factor kappa B inducing kinase suppresses inflammatory responses and the symptoms of chronic periodontitis in a mouse model

Chronic periodontitis is an inflammatory disease that represents a major public health issue nowadays. Here, we investigated the protective role of nuclear factor kappa B (NF-κB) inducing kinase (NIK)-inhibitor on chronic periodontitis and revealed the underlying molecular mechanism. NIK-inhibitor was synthesized, and its functions were examined in primary osteoclasts and wild-type (WT) and NIK-/- chronic periodontitis mouse model. Lipopolysaccharides (LPS) or activator of NF-κB was applied to stimulate inflammatory response of osteoclasts. The qRT-PCR, ELISA and Western blot were used to measure the expression of pro-inflammatory and osteoclast-related genes, and the activation of NF-κB signaling. Osteoclastogenesis and bone damage were detected by TRAP staining and micro-CT. NIK knockdown mice had lower expression of osteoclast-related genes and improved CEJ-ABC damage. Similarly, NIK-inhibitor administration inhibited inflammatory responses and CEJ-ABC damage in chronic periodontitis models. NIK-inhibitor suppressed osteoclastogenesis and osteoclast-related genes expression through inhibiting the non-canonical NF-κB signaling. NIK plays important role in bone destruction of chronic periodontitis and NIK-inhibitor represents a promising therapeutic strategy for this disease.

Combination of enamel matrix derivative and hyaluronic acid inhibits lipopolysaccharide-induced inflammatory response on human epithelial and bone cells

Objectives

The aim of this study was to evaluate the in vitro effect of enamel matrix derivative (EMD) and hyaluronic acid (HA) and their synergistic combination on lipopolysaccharides (LPS)-induced inflammation in human keratinocytes and osteoblasts.

Material and methods

Cells were challenged with LPS (1 μg/ml) and cultured in the following treatment groups with EMD (30 mg/ml) and HA (30 mg/ml): LPS, EMD, HA, EMD + HA, EMD + LPS, HA + LPS, and EMD + HA + LPS. Cell viability, inflammatory cytokine expression, and cell migration were determined using colorimetric assay, quantitative real-time polymerase chain reaction (qPCR), and scratch wound healing assay, respectively.

Results

Cell viability was decreased when exposed to LPS compared to the controls. Overall, LPS treatment expressed upregulation on inflammatory cytokine tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6). EMD and HA reduced up to 3.0-fold the cytokine expression caused by LPS (p < 0.05). EMD and HA statistically induced higher migration in osteoblasts and keratinocytes, respectively. Migration was impaired by LPS, whereas it significantly increased after addition of EMD and HA.

Conclusions

EMD and HA are advantageous biomaterials that individually generate strong directional migratory keratinocyte and osteoblast response. Their combination also enhances cell viability, and anti-inflammatory and migratory abilities to promote healing specially under LPS inflammatory stimulus. Future in vivo and animal research is necessary to further characterize the effect of EMD and HA on periodontal regeneration.

Clinical relevance

The use of EMD in conjunction with HA resulted in a reduction of inflammation and improvement of tissue healing at wound sites. Both biomaterials combined may potentially improve the effectiveness of bone regeneration in periodontal bone defects, pointing to the potential clinical relevance of both materials in regenerative periodontal surgery.

Pathological and Therapeutic Approach to Endotoxin-Secreting Bacteria Involved in Periodontal Disease

It is widely recognized that periodontal disease is an inflammatory entity of infectious origin, in which the immune activation of the host leads to the destruction of the supporting tissues of the tooth. Periodontal pathogenic bacteria like Porphyromonas gingivalis, that belongs to the complex net of oral microflora, exhibits a toxicogenic potential by releasing endotoxins, which are the lipopolysaccharide component (LPS) available in the outer cell wall of Gram-negative bacteria. Endotoxins are released into the tissues causing damage after the cell is lysed. There are three well-defined regions in the LPS: one of them, the lipid A, has a lipidic nature, and the other two, the Core and the O-antigen, have a glycosidic nature, all of them with independent and synergistic functions. Lipid A is the "bioactive center" of LPS, responsible for its toxicity, and shows great variability along bacteria. In general, endotoxins have specific receptors at the cells, causing a wide immunoinflammatory response by inducing the release of pro-inflammatory cytokines and the production of matrix metalloproteinases. This response is not coordinated, favoring the dissemination of LPS through blood vessels, as well as binding mainly to Toll-like receptor 4 (TLR4) expressed in the host cells, leading to the destruction of the tissues and the detrimental effect in some systemic pathologies. Lipid A can also act as a TLRs antagonist eliciting immune deregulation. Although bacterial endotoxins have been extensively studied clinically and in a laboratory, their effects on the oral cavity and particularly on periodontium deserve special attention since they affect the connective tissue that supports the tooth, and can be linked to advanced medical conditions. This review addresses the distribution of endotoxins associated with periodontal pathogenic bacteria and its relationship with systemic diseases, as well as the effect of some therapeutic alternatives.

Ecklonia cava Extract Exerts Anti-Inflammatory Effect in Human Gingival Fibroblasts and Chronic Periodontitis Animal Model by Suppression of Pro-Inflammatory Cytokines and Chemokines

Periodontitis is one of the most common chronic inflammatory diseases. The anti-inflammatory effect of the extract from brown algae Ecklonia cava was analyzed in lipopolysaccharide (LPS)-stimulated human gingival fibroblasts (HGF-1), the most abundant cells in gingival tissue. The gene expressions of cyclooxygenase-2 and interleukin-6 were decreased by 78 and 50%, respectively, at 100 μg/mL Ecklonia cava extract (ECE) treatment. The gene expressions of matrix metalloproteases (MMP-2 and MMP-8) and chemokines (macrophage inflammatory protein 1-alpha and stromal cell-derived factor 1) were also significantly down-regulated by ECE treatment (p < 0.05). The increased reactive oxygen species (ROS) production in HGF-1 cells by LPS stimulation was decreased by 30% at 100 μg/mL ECE treatment. The mitogen-activated protein kinase pathway and the nuclear factor-kappa B (NF-κB) signal activated by ROS were suppressed by ECE in a dose-dependent manner. ECE treatment (400 mg/kg, 8 weeks) significantly improved alveolar bone resorption in the ligature-induced chronic periodontitis rat model. ECE supplementation also lowered elevated mRNA expression of the receptor activator of nuclear factor-kappa B (RANKL)/osteoprotegerin (OPG) in the gingival tissue (p < 0.05). Therefore, ECE mitigated gingival tissue destruction and bone resorption associated with chronic periodontitis condition.

Effect of vitamin E on periodontitis: Evidence and proposed mechanisms of action

BACKGROUND

Periodontitis is a noncommunicable inflammatory disease of the soft tissue and bone surrounding the teeth in the jaw, which affects susceptible individuals with poor oral hygiene. A growing interest has been seen in the use of dietary supplements and natural products for the treatment and prevention of periodontitis. Vitamin E consists of two major groups, namely tocopherols and tocotrienols, which are botanical lipophilic compounds with excellent anti-inflammatory and antioxidant properties.

HIGHLIGHT

This review aimed to summarize the preclinical and clinical findings on the effects of vitamin E on periodontitis. The current literature suggests that vitamin E could improve the periodontal status by correcting redox status imbalance, reducing inflammatory responses, and promoting wound healing, thus highlighting the potential of vitamin E in the management of periodontitis.

CONCLUSION

Direct evidence for the use of vitamin E supplementation or treatment of periodontitis in humans is still limited. More well-designed and controlled studies are required to ascertain its effectiveness.

Adiponectin inhibits lipoplysaccharide-induced inflammation and promotes osteogenesis in hPDLCs

Periodontal diseases are infections of the structures that surround and support the teeth; they are characterized by local inflammation and alveolar bone loss. Most treatments focus on only one aspect, inhibiting inflammation, or promoting osteoblasts. We set out to develop a new method that would intervene in the two aspects simultaneously. Adiponectin (APN), secreted by adipocytes, inhibits the inflammatory response and promotes osteogenesis. However, its role in human periodontal ligament cells (hPDLCs) is unclear. Therefore, we aim to investigate whether APN could suppress lipopolysaccharide (LPS)-induced inflammation and promote osteogenesis in hPDLCs. In the present study, we stimulated hPDLCs with LPS in the presence or absence of APN. Real-time PCR and Western blotting results demonstrated that APN partially inhibited the activation of the classical nuclear factor κ-B (NF-κB) pathway. These results were confirmed by a change of expressions of NF-κB downstream inflammatory genes, such as decreased cyclooxygenase (COX)-2 and tumor necrosis factor α (TNF-α), along with increased interleukin (IL)-10. As for the role of APN in osteogenesis, Alizarin Red S staining showed that APN treatment induced more calcium deposition nodules than controls. We also found that APN enhanced the expression of osteoblast-related genes (osteopontin (OPN), collagen 1, osteocalcin, alkaline phosphatase, runt-related transcription factor 2 (RUNX2), and bone morphogenetic protein 2) in hPDLCs via the APPL1 (the adaptor protein containing PH domain, PTB domain, and leucine zipper motif 1)/p38 signal transduction pathway. Therefore, APN inhibits LPS-induced inflammation and promotes osteogenesis in hPDLCs and may have potential therapeutic value in treating periodontitis by inhibiting the inflammatory lesions and contributing to bone tissue regeneration.

The protective role of Ephrin-B2/EphB4 signaling in osteogenic differentiation under inflammatory environment

Inflammation and alveolar bone destruction constitute the main pathological process of periodontitis. However, the molecular mechanisms of bone destruction under the inflammation environment remain unclear. This study aims to explore the role of Ephrin-B2/EphB4 signaling in osteogenic differentiation under the inflammation environment. Mouse pre-osteoblasts MC3T3-E1 were pretreated with lipopolysaccharide of Porphyromonas gingivalis (Pg-LPS). The Ephrin-B2/EphB4 signaling was activated, and the osteogenic differentiation of cells was examined. The results showed that activation of Ephrin-B2/EphB4 signaling promoted the expression levels of osteogenic differentiation-related genes, and also relieved the inhibitory effect of Pg-LPS on osteogenesis. Noticeably, the effect of Ephrin-B2/EphB4 signaling might be related to the mitogen-activated protein kinase (MAPK) pathway. While applying Ephrin-B2-Fc and EphB4-Fc to periodontitis mice, we observed the reduction of alveolar crest destruction. The current study revealed the possible role of Ephrin-B2/EphB4 signaling in reducing bone destruction in periodontitis and suggested its potential values for further research.

Treatment of localized aggressive periodontitis alters local host immunoinflammatory profiles: A long-term evaluation

AIM

To evaluate the local immunoinflammatory profiles in localized aggressive periodontitis patients (LAP) before and after periodontal treatment and maintenance.

METHODS

Sixty-six African-Americans with LAP (7-21 years old) were included. After periodontal examination, all patients received periodontal treatment with mechanical debridement plus systemic amoxicillin/metronidazole for 7 days. Gingival crevicular fluid was collected from diseased and healthy sites at baseline and 3, 6, 12, and 24 months following treatment. Levels of 16 inflammatory/bone resorption markers were determined using Milliplex^® . Univariate and correlation analyses were performed among all parameters/biomarkers. Discriminant analyses (DA) evaluated profile differences between LAP diseased and healthy sites at each time point as compared to the baseline.

RESULTS

Reductions in the clinical parameters (except for visible plaque) were observed at all time points compared to the baseline. Levels of IL-12p70, IL-2, IL-6, MIP-1α, RANKL, and OPG were reduced after treatment, and several cytokines/chemokines were correlated with clinical parameters reductions. DA showed that differences in the immunoinflammatory profiles between LAP diseased and healthy sites decreased after periodontal treatment compared to the baseline.

CONCLUSIONS

Periodontal treatment modified the local immunoinflammatory profile of LAP sites in the long term, as suggested by changes in biomarkers from baseline, along with clinical stability of the disease. (Clinicaltrials.gov number, NCT01330719).

Expression of osteoclastogenic and anti-osteoclastogenic cytokines differs in mouse gingiva injected with lipopolysaccharide, peptidoglycan, or both

OBJECTIVE

Bacterial substances in subgingival biofilm evoke alveolar bone resorption. We previously reported that gingival injection of bacterial lipopolysaccharide (LPS) and peptidoglycan (PGN) induced alveolar bone resorption in mice. However, the mechanism by which LPS and PGN induce osteoclast formation has not been investigated. The aim of this study is to clarify the role of osteoclastogenic and anti-osteoclastogenic cytokines in the alveolar bone resorption induced by LPS and PGN.

MATERIALS

LPS from Escherichia coli, PGN from Staphylococcus aureus, or both were injected into the gingiva of mice every 48 h for a total of 13 times. Alveolar bone resorption was assessed histochemically by tartrate-resistant acid phosphatase staining. Expression of the receptor activator of nuclear factor-κB ligand (RANKL), tumor necrosis factor (TNF)-α, interleukin (IL)-17, and IL-10 were analyzed by immunostaining. To analyze the role of these cytokines, RANKL-pretreated mouse bone marrow macrophages were stimulated with LPS, PGN, or LPS + PGN with or without anti-TNF-α antibody, IL-17, or IL-10.

RESULTS

Alveolar bone resorption was induced by both LPS and PGN and exacerbated by LPS + PGN. LPS induced higher RANKL expression than PGN. Expression of TNF-α and IL-10 was correlated with bone resorption. PGN injections induced the strongest expression of IL-17, followed by LPS + PGN and LPS. In an in vitro osteoclastogenesis assay, anti-TNF-α antibody and IL-10 inhibited osteoclast formation, but IL-17 promoted it.

CONCLUSION

LPS, PGN, or LPS + PGN injections induce distinctive expression of TNF-α, IL-10, and IL-17, suggesting that the composition of these bacterial ligands in dental plaque is critical for alveolar bone resorption.

The role of inflammation and genetics in periodontal disease

Periodontitis is a complex disease: (a) various causative factors play a role simultaneously and interact with each other; and (b) the disease is episodic in nature, and bursts of disease activity can be recognized, ie, the disease develops and cycles in a nonlinear fashion. We recognize that various causative factors determine the immune blueprint and, consequently, the immune fitness of a subject. Normally, the host lives in a state of homeostasis or symbiosis with the oral microbiome; however, disturbances in homeostatic balance can occur, because of an aberrant host response (inherited and/or acquired during life). This imbalance results from hyper- or hyporesponsiveness and/or lack of sufficient resolution of inflammation, which in turn is responsible for much of the disease destruction seen in periodontitis. The control of this destruction by anti-inflammatory processes and proresolution processes limits the destruction to the tissues surrounding the teeth. The local inflammatory processes can also become systemic, which in turn affect organs such as the heart. Gingival inflammation also elicits changes in the ecology of the subgingival environment providing optimal conditions for the outgrowth of gram-negative, anaerobic species, which become pathobionts and can propagate periodontal inflammation and can further negatively impact immune fitness. The factors that determine immune fitness are often the same factors that determine the response to the resident biofilm, and are clustered as follows: (a) genetic and epigenetic factors; (b) lifestyle factors, such as smoking, diet, and psychosocial conditions; (c) comorbidities, such as diabetes; and (d) local and dental factors, as well as randomly determined factors (stochasticity). Of critical importance are the pathobionts in a dysbiotic biofilm that drive the viscious cycle. Focusing on genetic factors, currently variants in at least 65 genes have been suggested as being associated with periodontitis based on genome-wide association studies and candidate gene case control studies. These studies have found pleiotropy between periodontitis and cardiovascular diseases. Most of these studies point to potential pathways in the pathogenesis of periodontal disease. Also, most contribute to a small portion of the total risk profile of periodontitis, often limited to specific racial and ethnic groups. To date, 4 genetic loci are shared between atherosclerotic cardiovascular diseases and periodontitis, ie, CDKN2B-AS1(ANRIL), a conserved noncoding element within CAMTA1 upstream of VAMP3, PLG, and a haplotype block at the VAMP8 locus. The shared genes suggest that periodontitis is not causally related to atherosclerotic diseases, but rather both conditions are sequelae of similar (the same?) aberrant inflammatory pathways. In addition to variations in genomic sequences, epigenetic modifications of DNA can affect the genetic blueprint of the host responses. This emerging field will yield new valuable information about susceptibility to periodontitis and subsequent persisting inflammatory reactions in periodontitis. Further studies are required to verify and expand our knowledge base before final cause and effect conclusions about the role of inflammation and genetic factors in periodontitis can be made.

Chemokines and cytokines profile in whole saliva of patients with periodontitis

Clinical features suggest differences in immune response among periodontitis forms, albeit a large number of cytokines and chemokines remain to be evaluated. The saliva is an available source of mediators and its analysis would be valuable in order to understand pathophysiological differences. The objective of this study was analyze chemokines/cytokines profile in whole saliva of individuals with severe periodontitis (Stage III) presenting moderate [Grade B; GB] or rapid progression rate with a localized incisor-molar pattern [Grade C; GC/IMP]. A case-control study was designed for each periodontitis group. GB (n = 9) and GC/IMP (n = 7) patients and their healthy controls (C-GB, n = 9 and C-GC, n = 7) were evaluated. Non-stimulated saliva samples were assessed by a multiplex assay for a total of 40 cytokines, C-C and C-X-C motif chemokines. GC/IMP group presented higher levels of CCL17 and CCL27 (p = 0.04, FDR > 0.05), and lower levels of CCL2 (p = 0.04, FDR > 0.05) and CCL25 (p = 0.006, FDR < 0.05) when compared to its control. GB patients had higher levels of IL-6, IL-1β (p = 0.04, FDR > 0.05), and elevated pro-inflammatory (TNF-α,IL-1β,INF-γ,IL-6, IL-16): anti-inflammatory (IL-2, IL-4, IL-10) ratio (p = 0.01, FDR < 0.05) compared to its control [p-values by Mann-Whitney test, and False Discovery Rate (FDR) by Benjamini-Hochburg corrections]. CCL-chemokines and cytokines contributed to differences between GC/C-GC and GB/C-GB, respectively (p < 0.05, PERMANOVA test). These preliminary data revealed that each periodontitis phenotype presented distinct immune profiles differentially expressed in saliva compared to their related controls, suggesting differences in the etiopathogenesis of GB and GC/IMP.

Aggregatibacter actinomycetemcomitans leukotoxin: From mechanism to targeted anti-toxin therapeutics

Aggregatibacter actinomycetemcomitans is a Gram-negative bacterium associated with localized aggressive periodontitis, as well as other systemic diseases. This organism produces a number of virulence factors, all of which provide some advantage to the bacterium. Several studies have demonstrated that clinical isolates from diseased patients, particularly those of African descent, frequently belong to specific clones of A. actinomycetemcomitans that produce significantly higher amounts of a protein exotoxin belonging to the repeats-in-toxin (RTX) family, leukotoxin (LtxA), whereas isolates from healthy patients harbor minimally leukotoxic strains. This finding suggests that LtxA might play a key role in A. actinomycetemcomitans pathogenicity. Because of this correlation, much work over the past 30 years has been focused on understanding the mechanisms by which LtxA interacts with and kills host cells. In this article, we review those findings, highlight the remaining open questions, and demonstrate how knowledge of these mechanisms, particularly the toxin's interactions with lymphocyte function-associated antigen-1 (LFA-1) and cholesterol, enables the design of targeted anti-LtxA strategies to prevent/treat disease.

One-step treatment of periodontitis based on a core-shell micelle-in-nanofiber membrane with time-programmed drug release

As a chronic inflammatory disease, periodontitis is responsible for irreversible soft tissue damage and severe alveolar bone resorption. However, curative effects of current therapies are largely confined by the difficulty to simultaneously achieve anti-inflammation and bone regeneration. Also, the dynamic environment in oral cavity easily causes the drugs swallowed or rinsed away by saliva. We report here a one-step treatment based on a core-shell nanofiber membrane fabricated by coaxial electrospinning. Polymeric micelles containing SP600125 were distributed in the shell, while BMP-2 was incorporated in the core. After crosslinking, the nanofiber membrane displayed a prolonged degradation and release period up to 4 weeks. The release of SP600125 was detected at beginning, whereas BMP-2 was not released until day 12. Such a time-programmed release behavior was proved desirable for suppressing the expression of pro-inflammatory factors and enhancing the osteogenic induction in vitro. Further in vivo investigation confirmed that, by simply covering the periodontitis site with our nanofiber membrane, alveolar destruction was largely avoided and bone defects recovered within 2 month. Taken together, we believe that the use of our membrane with sequential release of SP600125 and BMP-2 may become a convenient and highly comprehensive therapy for periodontitis.

Salvianolic Acid C Attenuates LPS-Induced Inflammation and Apoptosis in Human Periodontal Ligament Stem Cells via Toll-Like Receptors 4 (TLR4)/Nuclear Factor kappa B (NF-κB) Pathway

BACKGROUND Periodontitis is a chronic inflammatory disease that causes gingival detachment and disintegration of alveolar bone. Salvianolic acid C (SAC) is a polyphenol compound with anti-inflammatory and antioxidant activities that is isolated from Danshen, a traditional Chinese medicine made from the roots of Salvia miltiorrhiza Bunge. The aim of this study was to investigate the mechanisms of underlying its protective effects and its inhibition effect on inflammation and apoptosis in human periodontal ligament stem cells (hPDLSCs). MATERIAL AND METHODS LPS-induced hPDLSCs, as a model mimicking an inflammatory process of periodontitis in vivo, were established to investigate the therapeutic effect of SAC in periodontitis. The inflammatory cytokines secretion and oxidative stress status were measured by use of specific commercial test kits. The hPDLSCs viability was analyzed by Cell Counting Kit-8 assay. The cell apoptosis and cell cycle were assayed with flow cytometry. Expressions levels of proteins involved in apoptosis, osteogenic differentiation, and TLR4/NF-kappaB pathway were evaluated by Western blotting. Alkaline phosphatase (ALP) activity was detected by ALP assay kit and ALP staining. The mineralized nodules formation of hPDLSCs was checked by Alizarin Red S staining. RESULTS Our results showed that LPS induced increased levels of inflammatory cytokines and oxidative stress and mediated the phosphorylation and nuclear translocation of NF‑kappaB p65 in hPDLSCs. SAC reversed the abnormal secretion of inflammatory cytokines and inhibited the TLR4/NF‑kappaB activation induced by LPS. SAC also upregulated cell viability, ALP activity, and the ability of osteogenic differentiation. The anti-inflammation and TLR4/NF‑kappaB inhibition effects of SAC were reversed by TLR4 overexpression. CONCLUSIONS Taken together, our results revealed that SAC effectively attenuates LPS-induced inflammation and apoptosis via the TLR4/NF-kappaB pathway and that SAC is effective in treating periodontitis.

Effects of dichloromethane Sarcophyton spp. extract on the lipopolysaccharide-induced expression of nuclear factor-kappa B and inducible nitric oxide synthase in mice

BACKGROUND AND AIM

The soft coral genus Sarcophyton is a source of cembraneterpen. Sarcophyton is reported to have anti-inflammatory properties, with the ability to reduce the expression of inducible nitric oxide synthase (iNOS) and inhibit nuclear factor-kappa B (NF-κB) activation. This study aimed to investigate the efficacy of dichloromethane (DCM) extracts of soft coral Sarcophyton spp. to inhibit the expression of NF-κB and iNOS induced by lipopolysaccharide (LPS).

MATERIALS AND METHODS

Crude extracts of Sarcophyton spp. were macerated with DCM (1:3 v/v) for 24 h. Thirty-six Balb/c mice were divided into six treatment groups, namely, normal control (without LPS induction), negative control (LPS induction 4 mg/mL), comparative control (LPS+Dexamethasone 6 mg/kg), and 3 concentration groups extract (LPS+50, 125, and 250 mg/kg). The expression of NF-κB and iNOS was measured in each treatment group.

RESULTS

Flow cytometry analysis showed that the relative number of NF-κB+ cells increased (18.38±1.24%) in LPS-induced mice compared with normal mice (13.24±1.15%). The Sarcophyton spp. DCM extracts decreased the relative number of NF-κB+ cells (125 mg/kg: 13.96±0.84%). Immunohistochemical analysis with ImmunoMembrane showed that LPS induction in mice increased iNOS expression when compared to normal mice. The Sarcophyton spp. DCM extracts reduced iNOS expression (especially at 125 mg/kg).

CONCLUSION

DCM extracts of Sarcophyton spp. inhibited the activation of NF-κB, resulting in suppressed iNOS expression, which directly inhibits NO production.

The impact of Aggregatibacter actinomycetemcomitans biofilm-derived effectors following antimicrobial photodynamic therapy on cytokine production in human gingival fibroblasts

BACKGROUND

Antimicrobial photodynamic therapy (aPDT) is an effective adjunctive therapeutic modality for the treatment of local infections, including periodontitis and peri-implantitis. After receiving aPDT, microbial cells in the biofilm structure may produce and/ or release soluble biofilm-derived effectors (BDEs), which may affect the biology of the host cells in the community context of their surrounding microenvironment. Given the fact that no study has investigated the role of BDEs following aPDT in the pathogenesis of infectious diseases, the aim of the current study was to determine the effect of BDEs of Aggregatibacter actinomycetemcomitans following exposure to sub-lethal doses of indocyanine green (ICG)-aPDT on human gingival fibroblasts (HGFs) in terms of cytokines produced.

MATERIALS AND METHODS

In this study, we evaluated the effect of biofilm-conditioned medium (BCM) resulting from the treatment of A. actinomycetemcomitans biofilm with a sub-lethal dose of aPDT on cytokines production, including IL-6, IL-8, CXCL10, TGF-β, and bFGF of HGFs using enzyme-linked immunoassays (ELISA). The sensitivity of cytokines to BDEs was determined by micro-titer plates.

RESULTS

The maximal sub-lethal dose of ICG-PDT was 20.15 μM/mL ICG at a fluence of 31.2 J/cm². The BCM of ICG-PDT-treated viable A. actinomycetemcomitans significantly reduced IL-6, IL-8, and CXCL10 levels compared to the BCM of untreated viable A. actinomycetemcomitans (78-, 93-, and 61.6-fold reduction, respectively; all P < 0.01). TGF-β and bFGF were strongly induced by BCM of ICG-PDT treated viable A. actinomycetemcomitans (by 57.7 and 36.1 folds, respectively; both P < 0.05). The BCM of untreated viable A. actinomycetemcomitans degraded most of the CxCL10, TGF-β and bFGF (58.8, 61.5, and 71.6%, respectively) in 24 h, while it degraded 9.3% of IL-6 and 15.1% of IL-8 after 24 h.

CONCLUSION

The results of the current study revealed that a sub-lethal dose of ICG-aPDT through the effect of BCM on HGFs could not only significantly reduce the production of pro-inflammatory cytokines but also promoted their role in periodontal regeneration due to increasing the bFGF level. Altogether, ICG-aPDT, with it's antimicrobial effects reduces inflammation and induces of tissue regeneration resulting from BCM, can be considered an efficient adjunctive therapeutic method for the treatment of local infections.

Estrogen receptor β suppresses inflammation and the progression of prostate cancer

Previous studies demonstrated that estrogen receptor β (ERβ) signaling alleviates systemic inflammation in animal models, and suggested that ERβ-selective agonists may deactivate microglia and suppress T cell activity via downregulation of nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB). In the present study, the role of ERβ in lipopolysaccharide (LPS)-induced inflammation and association with NF-κB activity were investigated in PC-3 and DU145 prostate cancer cell lines. Cells were treated with LPS to induce inflammation, and ELISA was performed to determine the expression levels of inflammatory cytokines, including tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein 1 (MCP-1), interleukin (IL)-1β and IL-6. MTT and Transwell assays, and Annexin V/propidium iodide staining were conducted to measure cell viability, apoptosis and migration, respectively. Protein expression was determined via western blot analysis. LPS-induced inflammation resulted in elevated expression levels of TNF-α, IL-1β, MCP-1 and IL-6 compared with controls. ERβ overexpression significantly inhibited the LPS-induced production of TNF-α, IL-1β, MCP-1 and IL-6. In addition, the results indicated that ERβ suppressed viability and migration, and induced apoptosis in prostate cancer cells, which was further demonstrated by altered expression of proliferating cell nuclear antigen, B-cell lymphoma 2-associated X protein, caspase-3, E-cadherin and matrix metalloproteinase-2. These effects were reversed by treatment with the ERβ antagonist PHTPP or ERβ-specific short interfering RNA. ERβ overexpression reduced the expression levels of p65 and phosphorylated NF-κB inhibitor α (IκBα), but not total IκBα expression in LPS-treated cells. In conclusion, ERβ suppressed the viability and migration of the PC-3 and DU145 prostate cancer cell lines and induced apoptosis. Furthermore, it reduced inflammation and suppressed the activation of the NF-κB pathway, suggesting that ERβ may serve roles as an anti-inflammatory and anticancer agent in prostate cancer.

Tanshinone IIA Attenuates Atherosclerosis in Apolipoprotein E Knockout Mice Infected with Porphyromonas gingivalis

Tanshinone IIA (TSA), a pharmacologically active component isolated from Danshen, may prevent cardiovascular diseases due to its anti-inflammatory, anti-oxidative, and anti-adipogenic effects. Porphyromonas gingivalis, a major periodontal pathogen, may contribute to the progression of atherosclerosis. Here, we studied the effects of TSA on atherosclerosis in ApoE^-/- mice with P. gingivalis infection. Eight-week-old ApoE^-/- mice were randomized to (a) phosphate-buffered saline (PBS), (b) P. gingivalis, and (c) P. gingivalis + TSA (60 mg kg^-1 day^-1). The mice were injected with (a) PBS, or (b) and (c) P. gingivalis 3 times per week for a total of 10 times. After 8 weeks, atherosclerotic risk factors in serum and in heart, aorta, and liver tissues were analyzed in all mice using Oil Red O, atherosclerosis cytokine antibody arrays, enzyme-linked immunosorbent assay (ELISA), real-time PCR, and microRNA array. CD40, G-CSF, IFN-γ, interleukin (IL)-1β, IL-6, MCP-1, MIP-3α, tumor necrosis factor-α (TNF-α), and VEGF were attenuated by TSA in atherosclerosis cytokine antibody arrays. TSA-treated mice showed a significant reduction of C-reactive protein (CRP), ox-LDL, IL-1β, IL-6, IL-12, and TNF-α in ELISA data. Real-time PCR analyses showed that TSA decreased the expression of CCL-2, CD40, IL-1β, IL-6, TNF-α, and MMP-2 in heart and aorta tissues. Moreover, hepatic CRP was downregulated by TSA, although FASN and HMG-CoA were not. The relative expressions of miR-146b and miR-155 were elevated by P. gingivalis infection and were downregulated by TSA treatment. These results suggest that TSA was a potential therapeutic agent that may have the ability to prevent P. gingivalis-induced atherosclerosis associated with anti-inflammatory and anti-oxidative effects.

Interferon Crevicular Fluid Profile and Correlation with Periodontal Disease and Wound Healing: A Systemic Review of Recent Data

The purpose of the present study was to see if there is a correlation between the effect of interferons in crevicular fluid and periodontitis, evaluating literature. Interferon gamma (IFN-γ) is an immunoregulatory cytokine that, when activated by its receptor, plays an important role in the activation of inflammatory processes, which are the basis of periodontal disease. Stem cells in the periodontal ligament, like stem cells from other tissues, have immunomodulatory capacity and are regulated by some cytokines such as interferon-γ (IFN-γ). The study searched MEDLINE databases from 2008 to 2018. Clinical human in vitro and in vivo studies had reported a correlation between interferon and periodontitis. The initial search obtained 359 citations. After screening and determination of eligibility, nine articles were included in the review. Significant (p < 0.05) increases in IFN-γ gene expression were observed in some studies in the chronic periodontitis group. In some cases it was suggested that molecular mechanisms underlie the possible roles of IFN-γ in the inhibition of osteoclastogenesis. Neopterin belongs to the chemical group known as pteridines. It is synthesised by human macrophages upon stimulation with the interferon-gamma. Neopterin concentrations in body fluids are high in the case of infections, immune diseases or graft rejection. In the chronic periodontitis group, this marker is significantly higher. These studies underlined the clinical evidence between interferons in the crevicular fluid and inflammatory response of periodontitis. However, there is a lack of scientific evidence that could lead the clinician to an interferon-modulated therapy because of periodontitis.

Radiographic Description of the Distribution of Aggressive Periodontitis in Primary Teeth

OBJECTIVE

To describe the prevalence by site and tooth of aggressive periodontists (AP) in primary teeth of children with AP, that will facilitate the early diagnosis of AP.

STUDY DESIGN

Radiographic evidence of AP by tooth and site of primary teeth of 29 children with AP was analyzed by gender, ethnicity, type of dentition (primary or mixed), alveolar bone site and type of tooth.

RESULTS

The range and mean ± standard error of number of sites and teeth per patient with AP were 4 to 28, 13.1±1.2 and 4 to 12, 8.3±0.5 respectively. The differences in prevalence of AP by gender, ethnicity, dentition and homologous sites at both sides of the mouth were not statistically significant (Chi square). AP was mostly diagnosed at the distal area of the maxillary canine, the proximal areas of the first maxillary primary molars, and the distal area of the mandibular first primary molar. The most affected teeth with AP were the first primary molars followed by the maxillary cuspid, and the second molars.

CONCLUSIONS

Examination of children's primary teeth should include abnormal mobility, when found it should be followed by radiographic evaluation for the presence of AP, taking in consideration the present findings.

MiR-29b aggravates lipopolysaccharide-induced endothelial cells inflammatory damage by regulation of NF-κB and JNK signaling pathways

MicroRNAs (miRNAs) have been reported to involve in variety of biological progresses. The present study aimed to explore the functional roles of miR-29b in endothelial cells inflammatory damage, as well as the underlying mechanisms. Lipopolysaccharide (LPS) was used to induce endothelial cell inflammation, and the role of miR-29b in endothelial cells inflammatory damage was detected by testing cell viability, cell apoptosis, and the expression of inflammation factors after the suppression or overexpression of miR-29b. Aiming to make clear of the underlying mechanism of miR-29b regulation in inflammation, we studied the relationship between miR-29b and NF-κB/JNK pathway in HUVEC and Eahy926 cells. The results showed that LPS significantly suppressed cell viability, promoted apoptosis and increased TNF-α, IL-1α and INF-γ secretions. MiR-29b was up-regulated in LPS-treated HUVEC and Eahy926 cells. Moreover, suppression of miR-29b alleviated LPS-induced inflammatory injury by promoting cell viability, decreasing apoptosis and reducing the secretions of TNF-α, IL-1α and INF-γ in both HUVEC and Eahy926 cells. On the contrary, overexpression of miR-29b aggravated cell inflammatory injury in both HUVEC and Eahy926 cells. Furthermore, LPS activated NF-κB and JNK signal pathways. However, suppression of miR-29b reduced LPS-activated NF-κB and JNK pathways in both HUVEC and Eahy926 cells. Taken together, these findings concluded that miR-29b could regulate LPS-induced endothelial cells inflammatory injury through regulation of NF-κB and JNK signaling pathways.

Effect of lipopolysaccharide derived from surabaya isolates of Actinobacillus actinomycetemcomitans on alveolar bone destruction

Background:

Actinobacillus actinomycetemcomitans’ lipopolysaccharide (LPS) has a high virulence factor. It interacts with serum protein through receptors on the epithelial cell surface, thereby increasing both interleukin (IL)-1β, and IL-6 which results in damage to periodontal tissue.

Aim:

The aim of the study was to identify and evaluate the effect of LPS derived from local isolates (A. actinomycetemcomitans) on the destruction of alveolar bone by means of several biomarkers, including; the number of osteoblasts and osteoclasts, the expression of IL-6, matrix metallopeptidase 1 (MMP-1), and receptor activator of nuclear factor kappa-Β ligand (RANKL).

Materials and Methods:

The isolation of LPS from A. actinomycetemcomitans was calculated using phenol, while purification was performed using Sephadex C-18 column chromatography. 40 Wistar rats were divided into four groups of 10. Each treatment was divided into two groups which were 0.9% NaCl and LPS induced for 7 and 14 days, respectively. Gingival and alveolar bones were further introduced into the induction area, followed by the measuring of osteoblast and osteoclast with hematoxylin-eosin staining, IL-6, MMP-1 and RANKL expression with immunohistochemical.

Results:

Reduced numbers of osteoblasts at the 7^th and 14^th day of treatment were detected, while those of osteoclasts increased. There was an increased expression of IL-6, MMP-1, and RANKL in the 7^th and 14^th-day treatment group. Treatment of LPS from A. actinomycetemcomitans over 7 and 14 days resulted in damage to periodontal tissue and alveolar bone in Wistar rats.

Conclusion:

LPS of A. actinomycetemcomitans administration for 7 and 14 days causes periodontal and alveolar tissue destruction in Wistar rats.

A new methanogen "Methanobrevibacter massiliense" isolated in a case of severe periodontitis

Background

A few methanogens have been previously recovered from periodontitis lesions, yet their repertoire may not be completed. We recovered a previously unreported methanogen species in this situation.

Case presentation

A 64-year-old Caucasian woman was diagnosed with chronic, severe generalized periodontitis. In the presence of negative controls, an 18-month culture of periodontal pockets in anaerobe Hungate tube yielded “Methanobrevibacter massiliense” and Pyramidobacter piscolens.

Conclusions

This case report provides evidence of the symbiotic strategy deployed by the methanogens and the anaerobes, and reports the first culture of a new methanogen, “M. massiliense”.

Electronic supplementary material

The online version of this article (10.1186/s13104-017-2980-3) contains supplementary material, which is available to authorized users.

Cytokine profile changes in gingival crevicular fluid after placement different brackets types

OBJECTIVE

The aim of this study was to examine the relationship between bracket design and ratio of five proinflammatory cytokine, in gingival crevicular fluid (GCF), and bacterial adhesion without tooth movement influence.

DESIGN

The sample was comprised of 20 participants, aged 11 to 15 years old (mean age: 13.3 years±1.03). A conventional Gemini™ metallic bracket and two self-ligating brackets, In-Ovation^®R and SmartClip™, were bonded to the maxillary incisors and canines. GCF was collected using a standard filter paper strip before and 60days after bonding. The cytokine levels (IL-12, IL-1α, IL-1β, IL-6 and TNF-α) were performed by the LUMINEX assay. The levels of the red and orange bacterial complexes were analyzed by the Checkerboard DNA-DNA hybridization. The data of cytokine and bacterial complexes were carried out using the non-parametric tests at 5% of significance level.

RESULTS

Increased cytokine levels were observed. However, only the SmartClip™ group showed a significantly increased level of TNF-α (p=0.046). The SmartClip™ brackets group presented higher levels of red complex bacteria.

CONCLUSIONS

The bracket design affected cytokine levels and bacterial adhesion since it was observed that the proinflammatory cytokines released in GCF to the SmartClip™ group showed an increase in the TNF-α levels associated with higher bacterial levels, which possibly represents greater inflammatory potential. Thereby, the bracket design should be considered in patients with risk of periodontal disease and root resorption.

Non-Surgical Therapy Reduces Presence of JP2 Clone in Localized Aggressive Periodontitis

BACKGROUND

Previous studies have provided substantial evidence of the association of Aggregatibacter actinomycetemcomitans, and its highly leukotoxic JP2 genotype, with localized aggressive periodontitis (LAgP). The present study aims to evaluate presence of JP2 in individuals with LAgP after periodontal treatment.

METHODS

Sixty African-American patients with LAgP, aged 5 to 25 years, were examined. At baseline, probing depth (PD), clinical attachment level (CAL), bleeding on probing, and plaque index were measured, and subgingival plaque was collected from LAgP diseased and healthy sites for each participant. Patients received whole-mouth ultrasonic debridement, scaling and root planing, and a 7-day prescription of amoxicillin and metronidazole. Participants were reevaluated and resampled and received regular maintenance therapy at 3, 6, and 12 months after treatment. Polymerase chain reaction was used to detect presence of the JP2 genotype before and after treatment.

RESULTS

At baseline, the JP2 sequence was identified in 75% of LAgP diseased sites and in 56.67% of healthy sites. At 3, 6, and 12 months after treatment, the number of patients was 40, 31, and 31, respectively, and JP2 detection decreased to 17.5%, 6.45%, and 3.23%, respectively, in diseased sites (P <0.001) and to 2.5%, 3.23%, and 0%, respectively, in healthy sites (P <0.001). Clinical parameters of disease were also significantly reduced after therapy (P <0.001). Additionally, significant correlations were observed between JP2 presence and mean PD (P <0.002) and CAL (P <0.001), after therapy.

CONCLUSION

Periodontal therapy was successful in reducing clinical parameters of LAgP and subgingival presence of JP2 in diseased and healthy sites.

Trace element and cytokine concentrations in patients with Fibrodysplasia Ossificans Progressiva (FOP): A case control study

Fibrodysplasia Ossificans Progressiva (FOP) is a rare inherited disease characterized by progressive heterotopic ossification. Disease onset, severity and symptoms vary between FOP patients, as does the frequency and activity of so-called flare-ups, during which tendons, ligaments, muscle and soft tissue are replaced by bone. Traumata, infections or other stressors are known inducers of flare-ups, and the hormone Activin A may be involved in disease activity; however, reliable biomarkers for FOP activity are missing, and the basal trace element and inflammatory state of patients are unknown. We hypothesized that FOP patients develop characteristic deficiencies in inflammation-related trace elements and display a chronically increased inflammatory cytokine level, collectively aggravating disease course and flare-up risk. Serum samples from 15 FOP patients and 25 relatives were collected under highest quality standards. Concentrations of Cu, Se and Zn were determined by total reflection X-ray fluorescence, and 27 cytokines along with Activin A by specific antibody-based techniques. Data were tested for normal distribution and analyzed by parametric or non-parametric tests. Concentrations of Se and Cu were not different between the groups, while Zn levels were slightly higher in FOP as compared to controls (1110±251 vs. 970±176ng/ml, P=0.04). The average concentrations of cytokines and Activin A were not different. When focusing on the two patients with self-reported flare-ups, again no obvious differences were noted. The cytokines Eotaxin, G-CSF, hbFGF and TNF-α were within the upper half of measured concentrations, and may warrant further longitudinal analyses. Our data do not support the hypothesis that FOP patients display a characteristic pattern of trace elements or have a generally increased tone of pro-inflammatory cytokines.

Mangiferin inhibits lipopolysaccharide-induced production of interleukin-6 in human oral epithelial cells by suppressing toll-like receptor signaling

OBJECTIVE

Oral epithelial cells have currently been found to play an important role in inflammatory modulation in periodontitis. Mangiferin is a natural glucosylxanthone with anti-inflammatory activity. The aim of this study was to investigate the regulatory effect of mangiferin on lipopolysaccharide (LPS)-induced production of proinflammatory cytokine interleukin-6 (IL-6) in oral epithelial cells and the underlying mechanisms.

DESIGN

The levels of LPS-induced IL-6 production in OKF6/TERT-2 oral keratinocytes were detected using enzyme-linked immunosorbent assay (ELISA). The expression of Toll-like receptor (TLR) 2 and TLR4 was determined using western blot analysis. And the phosphorylation of TLR downstream nuclear factor-κB (NF-κB), p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) was examined using cell-based protein phosphorylation ELISA kits.

RESULTS

We found that mangiferin reduced LPS-upregulated IL-6 production in OKF6/TERT-2 cells. Additionally, mangiferin inhibited LPS-induced TLR2 and TLR4 overexpression, and suppressed the phosphorylation of NF-κB, p38 MAPK and JNK. Moreover, mangiferin repressed IL-6 production and TLR signaling activation in a dose-dependent manner after 24h treatment.

CONCLUSIONS

Mangiferin decreases LPS-induced production of IL-6 in human oral epithelial cells by suppressing TLR signaling, and this glucosylxanthone may have potential for the treatment of periodontitis.

MicroRNA expression profile of human periodontal ligament cells under the influence of Porphyromonas gingivalis LPS

Periodontitis is a chronic inflammatory disease which is caused by bacterial infection and leads to the destruction of periodontal tissues and resorption of alveolar bone. Thus, special attention should be paid to the mechanism under lipopolysaccharide (LPS)-induced periodontitis because LPS is the major cause of periodontitis. However, to date, miRNA expression in the LPS-induced periodontitis has not been well characterized. In this study, we investigated miRNA expression patterns in LPS-treated periodontal ligament cells (PDLCs). Through miRNA array and differential analysis, 22 up-regulated miRNAs and 28 down-regulated miRNAs in LPS-treated PDLCs were identified. Seven randomly selected up-regulated (miR-21-5p, 498, 548a-5p) and down-regulated (miR-495-3p, 539-5p, 34c-3p and 7a-2-3p) miRNAs were examined by qRT-PCR, and the results proved the accuracy of the miRNA array. Moreover, targets of these deregulated miRNAs were analysed using the miRWalk database. Database for Annotation, Visualization and Integration Discovery software were performed to analyse the Gene Ontology and Kyoto Encyclopaedia of Genes and Genomes pathway of differential expression miRNAs, and the results shown that Toll-like receptor signalling pathway, cAMP signalling pathway, transforming growth factor-beta signalling pathway, mitogen-activated protein kinase (MAPK) signalling pathway and other pathways were involved in the molecular mechanisms underlying LPS-induced periodontitis. In conclusion, this study provides clues for enhancing our understanding of the mechanisms and roles of miRNAs as key regulators of LPS-induced periodontitis.

Microbial complexes levels in conventional and self-ligating brackets

OBJECTIVES

The aims were to evaluate the levels of bacterial species in saliva and in situ and to assess whether the design of brackets influences the risk of developing periodontal disease.

MATERIALS AND METHODS

Twenty patients (13.3 mean age) were bonded with self-ligating brackets and a conventional bracket. Saliva was collected before bonding and 30 and 60 days after bonding. One sample of each bracket was removed 30 and 60 days after bonding. The analysis was determined by checkerboard DNA-DNA hybridization. The data was evaluated by the non-parametric test.

RESULTS

A significant increase in the levels of bacterial species in the saliva occurred in 15 of the 22 analyzed species. The self-ligating brackets presented the highest incidence percentages for the orange and red complexes 60 days after bonding. In situ analyses showed different patterns according to the bracket design. The levels of Campylobacter rectus showed significant differences (p = 0.011) 60 days after bonding among the three brackets; the highest values were observed in the In-Ovation®R bracket.

CONCLUSIONS

The bracket design seems to influence the levels of bacterial species involved in periodontal disease. Considering the wide variety of bacterial species, additional studies are needed to aid in the establishment of effective protocols to prevent the development of periodontal disease during orthodontic treatment.

CLINICAL RELEVANCE

A dynamic alteration in the oral microbiota may lead to inflammatory reactions in the supporting soft and hard tissues. The different types of brackets interfere with bacterial adherence. Bracket design should be considered in orthodontic treatment.

Inflammatory Response Influences Treatment of Localized Aggressive Periodontitis

We previously reported a systemic hyperinflammatory response to bacterial lipopolysaccharide (LPS) in children with localized aggressive periodontitis (LAP). Additionally, different levels of this response were observed within the LAP group. It is unknown whether this hyperinflammatory response influences the clinical response to periodontal treatment in these children. Therefore, the goal of this study was to evaluate the influence of LPS responsiveness present prior to treatment on the clinical response to treatment within the LAP cohort. Prior to treatment, peripheral blood was collected from 60 African American participants aged 5 to 21 y, free of systemic diseases, and diagnosed with LAP. Blood was stimulated with ultrapure LPS from Escherichia coli, and Luminex assays were performed to quantify 14 cytokine/chemokine levels. Principal component and cluster analyses were used to find patterns of cytokine/chemokine expression among participants and subdivide them into clusters. Three distinct clusters emerged among LAP participants: a high responder group (high level of response for INFg, IL6, and IL12p40), a mixed responder group (low for some and high for other cytokines/chemokines), and a low responder group (low overall cytokine/chemokine response). Periodontal clinical parameters were compared among these groups prior to and 3, 6, and 12 mo following treatment with mechanical debridement and systemic antibiotics. High responders presented the lowest reductions in clinical parameters after treatment, whereas the low responders presented the highest reductions. In our LAP participants, distinct patterns of LPS response were significantly predictive of changes in clinical parameters after treatment. Future studies are needed to evaluate the underlying mechanisms predicting the heterogeneity of LAP activity, severity, and response to treatment (ClinicalTrials.gov NCT01330719).