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Microbiota dysbiosis may affect both the development and progression of colorectal cancer (CRC). Large metagenomic studies have highlighted specific oral bacteria linked to CRC including Porphyromonas gingivalis. Few studies have however analysed the implications of this bacterium in CRC progression and survival. In this study, we investigated the intestinal presence of P. gingivalis by qPCR in both faecal and mucosal samples from two different patient cohorts, including patients with precancerous dysplasia or CRC, as well as controls. P. gingivalis was detected in 2.6-5.3% of CRC patients and significantly different levels of P. gingivalis were found in faeces of CRC patients compared to controls (P = 0.028). Furthermore, an association was found between the presence of P. gingivalis in faeces and tumour tissue (P < 0.001). Our findings further suggested a potential link between mucosal P. gingivalis and tumours of MSI subtype (P = 0.040). Last but not least, patients with faecal P. gingivalis were found to have a significantly decreased cancer-specific survival (P = 0.040). In conclusion, P. gingivalis could be linked to patients with CRC and to a worse patient prognosis. Further studies are needed to elucidate the role of P. gingivalis in CRC pathogenesis.

Porphyromonas gingivalis (P. gingivalis) is a Gram-negative anaerobe involved in the pathogenesis of chronic periodontitis, including local inflammation of the oral cavity. However, periodontal disease has recently been identified as a significant factor in the pathogenesis of neural diseases, including Alzheimer's disease. A virulence factor, P. gingivalis-lipopolysaccharide (LPS-PG), is involved in pro-inflammatory responses, not only in peripheral tissues but also in the brain. In this study, we examined whether P. gingivalis-induced brain inflammation could be ameliorated by pharmacotherapy, using in vivo and in vitro studies. In an animal experiment, peripheral administration of LPS-PG induced inflammation in the hippocampus via microglial activation, which was inhibited by pre-treatment with the antidepressant imipramine. Similarly, LPS-PG-induced inflammation in MG-6 cells, a mouse microglial cell line, was inhibited by pre-treatment with imipramine, which caused imipramine-induced inhibition of NF-κB signaling. Culture media obtained from LPS-PG-treated MG-6 cells induced neuronal cell death in Neuro-2A cells, a mouse neuroblastoma cell line, which was prevented by pre-treatment of MG-6 cells with imipramine. These results indicate that imipramine inhibits LPS-PG-induced inflammatory responses in microglia and ameliorates periodontal disease-related neural damage.

Background: Gourami fish scales, often considered as a waste, turned out to be an alternative source for antibacterial components. Its extract contains alkaloid, an antibacterial agent, while also contains hydrogen bonds which have the effect of increasing the interaction with other substances. Curcumin is one of the active ingredients of turmeric, a spice commonly used as an herbal medicine in Indonesia. Curcumin could suppress bacterial proliferation by inhibiting virulence agents. The combination of these substances was expected to help inhibitPorphyromonas gingivalisgrowth, one of the key pathogens in periodontitis patients. Objective: This study aims to determine the inhibitory effect of the gourami fish scale extract-curcumin combination on the growth ofP. gingivalisbacteria. Method: This research is anin vitroexperimental analytical laboratory research. The concentrations used are 100%; 50%; 25%; 12.5%; 6.25%; 3.125%; 1.56%; and 0.78%. The inhibition testing onP. gingivalisbacteria cultures was carried out by spectrophotometric methods and colony counts. Results: Gourami fish scale extract-curcumin combination with a concentration of 12.5%; 25%; 50%; and 100% killed colonies ofP. gingivalisbacteria resulting in 0 colonies. A concentration of 6.25% inhibits bacterial growth by 92.9%. The statistical test result showed a significant difference (p < 0.05). Conclusion: Gourami fish scale extract-curcumin combination has an inhibitory effect on the growth ofP. gingivalisbacteria with MIC value at the concentration of 6.25% and MBC of 12.5%.

Background/Aim: The oral bacteria involved in the development of periodontitis alter the tissue conditions and modify immune responses in a way that may also influence tumor development. We investigated the prevalence of R gingipain (Rgp), a key virulence factor of the oral pathobiont Porphyromonas gingivalis, and the tissue-destructive enzymes matrix metalloproteinase 8 (MMP-8) and 9 (MMP-9) in 202 unselected consecutive oropharyngeal squamous cell carcinoma

Periodontitis is a chronic inflammatory disease caused by the interaction of oral microorganisms with the host immune response.

Recent genome-wide association studies have suggested novel risk loci associated with periodontitis, which is initiated by dysbiosis in subgingival plaque and leads to destruction of teeth-supporting structures. One such genetic locus was the tumor necrosis factor receptor–associated factor 3 interacting protein 2 ( TRAF3IP2), a gene encoding the gate-keeping interleukin (IL)–17 receptor adaptor. In this study, we first determined that carriers of the lead exonic variant rs13190932 within the TRAF3IP2 locus combined with a high plaque microbial burden was associated with more severe periodontitis than noncarriers. We then demonstrated that TRAF3IP2 is essential in the IL-17–mediated CCL2 and IL-8 chemokine production in primary gingival epithelial cells. Further analysis suggested that rs13190932 may serve a surrogate variant for a genuine loss-of-function variant rs33980500 within the same gene. Traf3ip2 null mice ( Traf3ip2–/–) were more susceptible than wild-type (WT) mice to the Porphyromonas gingivalis–induced periodontal alveolar bone loss. Such bone loss was associated with a delayed P. gingivalis clearance and an attenuated neutrophil recruitment in the gingiva of Traf3ip2–/– mice. Transcriptomic data showed decreased expression of antimicrobial genes, including Lcn2, S100a8, and Defb1, in the Traf3ip2–/– mouse gingiva in comparison to WT mice prior to or upon P. gingivalis oral challenge. Further 16S ribosomal RNA sequencing analysis identified a distinct microbial community in the Traf3ip2–/– mouse oral plaque, which was featured by a reduced microbial diversity and an overabundance of Streptococcus genus bacteria. More P. gingivalis was observed in the Traf3ip2–/– mouse gingiva than WT control animals in a ligature-promoted P. gingivalis invasion model. In agreement, neutrophil depletion resulted in more local gingival tissue invasion by P. gingivalis. Thus, we identified a homeostatic IL-17-TRAF3IP2-neutrophil axis underpinning host defense against a keystone periodontal pathogen.

The translocation of oral bacteria, including Porphyromonas gingivalis, to the gut has been shown to alter gut microbiome. However, the effect of P. gingivalis on gut microbiome in relation to aging has not been demonstrated. We hypothesize that P. gingivalis has more detrimental effect on gut environment with increased age. The objective of this study is to investigate the effect of P. gingivalis on gut environment using aged mice.C57BL/6J mice aged 4 weeks (young) or 76 weeks (old) were divided into four groups: control-young, control-old, P. gingivalis-administered young, and P. gingivalis-administered old. P. gingivalis was orally administered thrice weekly for 5 weeks. At 30 days after the last P. gingivalis administration, 16S rRNA sequencing was performed to study the gut microbiome. The mRNA and protein expression of intestinal junctional barrier molecules and the levels of the inflammatory cytokines IL-1β and TNF-α in the serum were evaluated.Significant differences in the gut microbiomes between the groups, in terms of taxonomic abundance, bacterial diversity, and predicted metagenome function, were observed. A significant reduction in the alpha diversity and in the abundance of beneficial bacteria, such as Akkermansia and Clostridiaceae, in the P. gingivalis-administered old mice was observed. The mRNA and protein levels of Claudin-1 and Claudin-2 in the intestine were significantly elevated, while E-cadherin was significantly downregulated in the P. gingivalis-administered old mice, as were the serum levels of IL-1β and TNF-α.The effect of P. gingivalis on the gut environment is more pronounced in old mice than in young mice.

Background. Despite their benefits, dental implants may sometimes fail for a diversity of causes; the most common reasons of failure are infection and bone loss. Porphyromonas gingivalis (P.gingivalis) bacteria show a major role in peri-implantitis infection and dental implant failure. Methods. In this study, the prevalence of P. gingivalis isolated from the gingival crevicular fluid (GCF) of fifteen Iranian patients with implant failure (more than 1/3 of the implant length), who had average oral and dental hygiene and no antibiotic use for at least one month, was determined. Moreover, the antimicrobial effects of curcumin nanocrystals against isolated P.gingivalis were investigated. The collected samples from patients were transferred to a microbiology laboratory to culture. The presence of P. gingivalis in the culture media was confirmed using a trypsin reagent test. An isolate from a patient with the highest colony count was selected to evaluate the antibacterial effects of curcumin nanoparticles. The inhibition zone diameter, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were determined. Results. Out of fifteen patients, eight (53.33%) were positive for the presence of P.gingivalis. The results of the microbial tests showed that curcumin nanoparticles had an MIC of 6.25 µg/mL and an MBC of 12.5 µg/mL. Conclusions. The use of curcumin nanoparticles may control the bacterial infection around the implant.

The occurrence and development of inflammation are closely correlated to the polarization of macrophages. All-trans retinoic acid (ATRA) has been proven to promote the polarization of macrophages from M1 to M2, but this lacks an effective carrier to participate in the biological response. The present study aims to determine whether retinoic acid-incorporated glycol chitosan (RA-GC) nanoparticles can regulate macrophage polarization in Porphyromonas gingivalis-lipopolysaccharide (Pg-LPS)-induced inflammation.Mouse 264.7 cell lines were treated with 1 µg/mL Pg-LPS to induce inflammation. After the effects of ATRA and RA-GC on the activity of macrophages were detected by CCK-8 assay, cells induced with Pg-LPS were assigned to the blank control group (GC) nanoparticles without ATRA, and experimental groups (GC nanoparticles loaded with different concentrations of ATRA: 1, 10 and 100 µg/mL). The effects of RA-GC on inflammatory cytokines tumor necrosis factor-α, interleukin (IL)-10 and IL-12 in macrophages were detected by enzyme-linked immunosorbent assay (ELISA). Subsequently, the effects of GC nanoparticles loaded with/without ATRA on macrophage polarization in an inflammatory environment were detected by RT-PCR and Western blotting.The results revealed that RA-GC had no significant effect on macrophage activity. However, RA-GC could effectively inhibit the Pg-LPS-induced inflammatory factor expression in macrophages. Meanwhile, the experimental results confirmed that RA-GC could downregulate the expression of inducible nitric oxide synthase (iNOS) (a marker of M1 macrophages) and upregulate the expression of mannose receptor and Arginase-1 (a marker of M2 macrophages) in a dose-dependent manner.The present study confirms that RA-GC can promote the M2 polarization of macrophages in an inflammatory environment, and proposes this as a promising target for the clinical treatment of Pg-LPS-related diseases.

Pathogenic bacteria utilize specialized macromolecular secretion systems to transport virulence factors across membrane(s) and manipulate their infected host. To date, 11 secretion systems have been identified, including the type IX secretion system (T9SS) associated with human, avian and farmed-fish diseases. As a bacterial secretion system, the T9SS also facilitates gliding motility and the degradation of different macromolecules by the secretion of metabolic enzymes in nonpathogenic bacteria. PorX is a highly conserved protein that regulates the transcription of essential T9SS components and additionally mediates the function of T9SS via direct interaction with PorL, the rotary motor protein of the T9SS. PorX is also a member of a two-component system regulatory cascade, where it serves as the response regulator that relays a signal transduced from a conserved sensor histidine kinase, PorY, to a designated sigma factor. Here, the recombinant expression and purification of PorX homologous proteins from the pathogenic bacterium Porphyromonas gingivalis and the nonpathogenic bacterium Flavobacterium johnsoniae are reported. A bioinformatical characterization of the different domains comprising the PorX protein is also provided, and the crystallization and X-ray analysis of PorX from F. johnsoniae are reported.

The immune response mediated by Th17 cells is essential in the pathogenesis of periodontitis. Emerging evidence has demonstrated that lipopolysaccharide from

Extensive research in humans and animal models has begun to unravel the complex mechanisms that drive the immunopathogenesis of periodontitis. Neutrophils mount an early and rapid response to the subgingival oral microbiome, producing destructive enzymes to kill microbes. Chemokines and cytokines are released that attract macrophages, dendritic cells, and T cells to the site. Dendritic cells, the focus of this review, are professional antigen-presenting cells on the front line of immune surveillance. Dendritic cells consist of multiple subsets that reside in the epithelium, connective tissues, and major organs. Our work in humans and mice established that myeloid dendritic cells are mobilized in periodontitis. This occurs in lymphoid and nonlymphoid oral tissues, in the bloodstream, and in response to Porphyromonas gingivalis. Moreover, the dendritic cells mature in situ in gingival lamina propria, forming immune conjugates with cluster of differentiation (CD) 4+ T cells, called oral lymphoid foci. At such foci, the decisions are made as to whether to promote bone destructive T helper 17 or bone-sparing regulatory T cell responses. Interestingly, dendritic cells lack potent enzymes and reactive oxygen species needed to kill and degrade endocytosed microbes. The keystone pathogen P. gingivalis exploits this vulnerability by invading dendritic cells in the tissues and peripheral blood using its distinct fimbrial adhesins. This promotes pathogen dissemination and inflammatory disease at distant sites, such as atherosclerotic plaques. Interestingly, our recent studies indicate that such P. gingivalis-infected dendritic cells release nanosized extracellular vesicles called exosomes, in higher numbers than uninfected dendritic cells do. Secreted exosomes and inflammasome-related cytokines are a key feature of the senescence-associated secretory phenotype. Exosomes communicate in paracrine with neighboring stromal cells and immune cells to promote and amplify cellular senescence. We have shown that dendritic cell-derived exosomes can be custom tailored to target and reprogram specific immune cells responsible for inflammatory bone loss in mice. The long-term goal of these immunotherapeutic approaches, ongoing in our laboratory and others, is to promote human health and longevity.

Aims Accumulating evidence suggests that Porphyromonas gingivalis is closely associated with the development of various chronic inflammatory diseases, particularly periodontitis. This study investigated the antibacterial activity and action mechanism of a novel antimicrobial peptide (AMP), DP7, against P. gingivalis. Methods and Results The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for DP7 were determined via a broth microdilution method, revealing an MIC of 8 μg ml−1 and MBC of 32 μg ml−1. Growth inhibition and killing assays confirmed the bactericidal effect of DP7, and treatment with DP7 at MBC eliminated P. gingivalis within 8 h. DP7 had a low cytotoxic effect against human cells. Transmission electron microscopy revealed that DP7 destroyed the bacterial membrane, and confocal laser scanning microscopy revealed its inhibitory effect on P. gingivalis biofilms. Quantitative reverse transcription-polymerase chain reaction revealed DP7-mediated inhibition of several virulence factor genes, partially explaining its antibacterial mechanism. Conclusions DP7, a novel AMP with low mammalian cytotoxicity, inhibits both planktonic and biofilm forms of P. gingivalis by destroying the bacterial membrane and reducing virulence factor gene expression. Significance and Impact of the Study DP7 has potential clinical application in the prevention and treatment of P. gingivalis-associated diseases.

Porphyromonas gingivalis exacerbates tissue hypoxia and worsens periodontal inflammation. This study investigated the effect of a therapeutic oxygen carrier (M101), derived from Arenicola marina, on hypoxia and associated inflammation in the context of periodontitis.The effect of M101 on GLUT-1, GLUT-3, HIF-1α, and MMP-9 expression, hypoxia, and antioxidant status in oral epithelial cells (EC) exposed to CoClM101 downregulated GLUT-1, GLUT-3, HIF-1α, and MMP-9 levels in EC exposed to CoClM101 showed promise in resolving hypoxia and associated inflammation-mediated tissue degradation. Its potential in the clinical management of periodontitis must be further investigated.

Soft tissue integration surrounding dental implant is considered as a biological barrier against the oral microorganisms and external stimuli. At present, successful soft tissues integration around implants remains a challenge. The aim of this study was to evaluate the effects of nanostructured zirconia abutment surfaces on fibroblasts viability and Porphyromonas gingivalis adhesion, which are the two main factors influencing the quality of peri-implant soft-tissue seal. Zirconia samples were made from three-dimensional gel deposition approach and divided into three groups: zirconia surfaces, zirconia film coated surfaces (CZr) and polished surfaces (PZr). The Surface properties were characterized by scanning electron microscopy, atomic force microscopy and water contact angle. The behavior of human gingival fibroblasts (HGFs) on samples, including of proliferation, morphology, gene expression and protein expression as well as collagen synthesis were assessed. Additionally, the adhesion of P. gingivalis on samples was analyzed by scanning electron microscopy and live/dead staining. CZr and PZr group significantly enhanced fibroblasts viability such as cell proliferation, cell spreading and extracellular matrix secretion, and impaired P. gingivalis adhesion. Therefore, our findings demonstrated that CZr and PZr surfaces with nano-grains or grinding grooves might be considered as the feasible zirconia abutments substrate for reinforcing HGFs response and minimizing P. gingivalis adhesion, and thereby enhance peri-implant soft-tissue integration.

The periodontal pathogen Porphyromonas gingivalis is genetically heterogeneous. However, the spontaneous generation of phenotypically different sub-strains has also been reported. McKee et al. (1988) cultured P. gingivalis W50 in a chemostat during investigations into the growth and properties of this bacterium. Cell viability on blood agar plates revealed two types of non-pigmenting variants, W50 beige (BE1), and W50 brown (BR1), in samples grown in a high-hemin medium after day 7, and the population of these variants increased to approximately 25% of the total counts by day 21. W50, BE1 and BR1 had phenotypic alterations in pigmentation, reduced protease activity and haemagglutination and susceptibility to complement killing. Furthermore, the variants exhibited significant attenuation in a mouse model of virulence. Other investigators showed that in BE1, the predominant extracellular Arg-gingipain was RgpB, and no reaction with an A-lipopolysaccharide-specific MAb 1B5 (Collinson et al., 1998; Slaney et al., 2006). In order to determine the genetic basis for these phenotypic properties, we performed hybrid DNA sequence long reads using Oxford Nanopore and the short paired-end DNA sequence reads of Illumina HiSeq platforms to generate closed circular genomes of the parent and variants. Comparative analysis indicated loss of intact kgp in the 20 kb region of the hagA-kgp locus in the two variants BE1 and BR1. Deletions in hagA led to smaller open reading frames in the variants, and BR1 had incurred a major chromosomal DNA inversion. Additional minor changes to the genomes of both variants were also observed. Given the importance of Kgp and HagA to protease activity and haemagglutination, respectively, in this bacterium, genomic changes at this locus may account for most of the phenotypic alterations of the variants. The homologous and repetitive nature of hagA and kgp and the features at the inverted junctions are indicative of specific and stable homologous recombination events, which may underlie the genetic heterogeneity of this species.

BackgroundPeriodontitis and oral pathogenic bacteria can contribute to the development of rheumatoid arthritis (RA). A connection between serum antibodies to Porphyromonas gingivalis (P. gingivalis) and RA has been established, but data on saliva antibodies to P. gingivalis in RA are lacking. We evaluated antibodies to P. gingivalis in serum and saliva in two Swedish RA studies as well as their association with RA, periodontitis, antibodies to citrullinated proteins (ACPA), and RA disease activity.MethodsThe SARA (secretory antibodies in RA) study includes 196 patients with RA and 101 healthy controls. The Karlskrona RA study includes 132 patients with RA ≥ 61 years of age, who underwent dental examination. Serum Immunoglobulin G (IgG) and Immunoglobulin A (IgA) antibodies and saliva IgA antibodies to the P. gingivalis–specific Arg-specific gingipain B (RgpB) were measured in patients with RA and controls.ResultsThe level of saliva IgA anti-RgpB antibodies was significantly higher among patients with RA than among healthy controls in multivariate analysis adjusted for age, gender, smoking, and IgG ACPA (p = 0.022). Saliva IgA anti-RgpB antibodies were associated with RA disease activity in multivariate analysis (p = 0.036). Anti-RgpB antibodies were not associated with periodontitis or serum IgG ACPA.ConclusionPatients with RA had higher levels of saliva IgA anti-RgpB antibodies than healthy controls. Saliva IgA anti-RgpB antibodies may be associated with RA disease activity but were not associated with periodontitis or serum IgG ACPA. Our results indicate a local production of IgA anti-RgpB in the salivary glands that is not accompanied by systemic antibody production.

Introduction: The oral pathogen Porphyromonas gingivalis is not only associated with periodontitis but also with systemic diseases elsewhere in the body. The mechanisms by which P. gingivalis travels from the oral cavity to other organs in the body are largely unknown. This review describes the four putative mechanisms supported by experimental evidence, which enable translocation of P. gingivalis over the oral mucosa, endothelial barriers and subsequent dissemination into the bloodstream. Mechanisms: The first mechanism: proteolytic enzymes secreted by P. gingivalis degrade adhesion molecules between tissue cells, and the extracellular matrix. This weakens the structural integrity of the mucosa and allows P. gingivalis to penetrate the tissue. The second is transcytosis: bacteria actively enter tissue cells and transfer to the next layer or the extracellular space. By travelling from cell to cell, P. gingivalis reaches deeper structures. Thirdly, professional phagocytes take up P. gingivalis and travel to the bloodstream where P. gingivalis is released. Lastly, P. gingivalis can adhere to the hyphae forming Candida albicans. These hyphae can penetrate the mucosal tissue, which may allow P. gingivalis to reach deeper structures. Conclusion: More research could elucidate targets to inhibit P. gingivalis dissemination and prevent the onset of various systemic diseases.

The Gram-negative anaerobic rod Porphyromonas gingivalis (P. gingivalis) is regarded as a keystone pathogen in periodontitis and expresses a multitude of virulence factors iincluding fimbriae that are enabling adherence to and invasion in cells and tissues. The progression of periodontitis is a consequence of the interaction between the host immune response and periodontal pathogens. The aim of this study was to investigate the genome-wide impact of recombinant fimbrial protein FimA from P. gingivalis W83 on the gene expression of oral squamous carcinoma cells by transcriptome analysis.Human squamous cell carcinoma cells (SCC-25) were stimulated for 4 and 24 h with recombinant FimA. RNA sequencing was performed and differential gene expression and enrichment were analyzed using gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and REACTOME. The results of transcriptome analysis were validated using quantitative real-time polymerase chain reaction (PCR) with selected genes.Differential gene expression after 4 and 24 h revealed upregulation of 464 (4 h) and 179 genes (24 h) and downregulation of 69 (4 h) and 312 (24 h) genes. GO, KEGG, and REACTONE enrichment analysis identified a strong immunologic transcriptomic response signature after 4 h. After 24 h, mainly those genes were regulated, which belonged to cell metabolic pathways and replication. Real-time PCR of selected genes belonging to immune response and signaling demonstrated strong upregulation of CCL20, TNFAIP6, CXCL8, TNFAIP3, and NFkBIA after both stimulation times.These data shed light on the RNA transcriptome of human oral squamous carcinoma epithelial cells following stimulation with P. gingivalis FimA and identify a strong immunological gene expression response to this virulence factor. The data provide a base for future studies of molecular and cellular interactions between P. gingivalis and oral epithelium to elucidate basic mechanisms that may provide new prospects for periodontitis therapy and give new insights into the development and possible treatments of cancer.

The aim of this study was to evaluate the effect of the administration of pasteurized Akkermansia muciniphila and Amuc_1100 on periodontal destruction in lean and obese mice and to determine the impact of the mode of administration.Porphyromonas gingivalis-associated experimental periodontitis was induced in lean and obese mice. After 3 weeks, live, pasteurized A. muciniphila or Amuc_1100 was administered by oral or gastric gavage for three additional weeks. Moreover, an evaluation of the interaction between A. muciniphila and P. gingivalis was performed by RNA-sequencing, and cytokines secretion was measured in exposed macrophages.Oral administration of live, pasteurized A. muciniphila or Amuc_1100 significantly decreased P. gingivalis-induced periodontal destruction and inflammatory infiltrate in lean and obese mice and contributed to the reduction of the plasma level of TNF-α and to the increase of IL-10. The co-culture of A. muciniphila and P. gingivalis induced an increased expression of genes linked to the synthesis of monobactam-related antibiotics in A. muciniphila, while a decrease of the gingipains and type IX secretion system was observed in P. gingivalis. In P. gingivalis-infected macrophages, pasteurized A. muciniphila decreased TNF-α and increased IL-10 levels.Pasteurized A. muciniphila can counteract P. gingivalis-associated periodontal destruction.

Objective. miR-141-3p has been demonstrated to be both anti-inflammatory and osteoprotective. This study is aimed at investigating the effect of miR-141-3p on osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) stimulated by Porphyromonas gingivalis lipopolysaccharide (PgLPS) and its mechanism. Methods. PgLPS was used to induce an inflammatory environment, and overexpression of miR-141-3p was done to assess its effect on hPDLSCs in an inflammatory environment. The level of miR-141-3p and EZH2 in hPDLSCs from each treatment group was detected via qRT-PCR, and the inflammatory factors IL-6 and IL-8 in the supernatant of each group were detected by ELISA. ALP staining and alizarin red staining were used to assess the effect of miR-141-3p on the osteogenic differentiation ability of hPDLSCs, and also, western blot was used to detect expression of osteogenic differentiation-related proteins. Further, dual-luciferase reporter assay examined whether miR-141-3p targeted EZH2. Results. PgLPS led to a significant decrease of miR-141-3p in hPDLSCs. Overexpression of miR-141-3p could enhance ALP activity and alizarin red staining intensity and increase Runx2, OPN and OCN protein expression levels in PgLPS-treated hPDLSCs. Additionally, miR-141-3p could reduce IL-6 and IL-8. miR-141-3p could target and negatively regulate EZH2, and overexpression of EZH2 reversed the promoting effect of miR-141-3p on osteogenic differentiation. Conclusion. miR-141-3p can attenuate PgLPS-induced inhibition of osteogenic differentiation and inflammation in hPDLSCs by negatively regulating EZH2.

Background/Purpose Viruses-bacteria synergistic interaction is associated with destructive periodontal diseases. However, the underlying mechanism for tissue destruction is not fully elucidated. In this study, lipopolysaccharide from Porphyromonas gingivalis (Pg-LPS) and polyinosinic-polycytidylic acid (poly I:C) were used to simulate bacteria and viruses, respectively. The possible combined effects of both molecular patterns on secretion of interleukin (IL)-6 and prostaglandin E2 (PGE2) from osteoblasts were determined. The effects of povidone-iodine (PVP-I) on the secretion of IL-6 and PGE2 were also examined. Methods Viability of treated osteoblastic cells (MG63) was examined by detection the mitochondrial dehydrogenase activity. Secretion of IL-6 and PGE2 was detected using the enzyme-linked immunosorbent assay (ELISA). Mitogen-activated protein kinases (MAPKs) and cyclooxygenase-2 (COX-2) were determined using the Western blotting analysis. Results Pg-LPS or poly I:C significantly enhanced the production of IL-6 and PGE2 in MG63 cells. The additive/synergistic effects of Pg-LPS/poly I:C on production of IL-6 and PGE2 were evident. The levels of phosphorylation of p38 MAPK and c-Jun N-terminal kinase (JNK) and expression of COX-2 protein were enhanced by Pg-LPS and/or poly I:C. On the other hand, the level of phosphorylation of extracellular signal-regulated kinase (ERK) was reduced by Pg-LPS and/or poly I:C. The stimulatory secretion of PGE2 by poly I:C was significantly reduced by PVP-I. Conclusion Concomitant infection of viruses and bacteria may be potentially harmful to the tooth supporting tissues by production of proinflammatory mediators. The results suggest the potential anti-inflammatory effect of PVP-I on bacterial or viral infection.

Human bone marrow stromal cell (hBMSC)–derived exosomes are promising therapeutics for inflammatory diseases due to their unique microRNA (miRNA) and protein cargos. Periodontal diseases often present with chronicity and corresponding exuberant inflammation, which leads to loss of tooth support. In this study, we explored whether hBMSC exosomes can affect periodontitis progression. hBMSC exosomes were isolated from cell culture medium through sequential ultracentrifugation. miRNAs and proteins that were enriched in hBMSC exosomes were characterized by RNA sequencing and protein array, respectively. hBMSC exosomes significantly suppressed periodontal keystone pathogen Porphyromonas gingivalis–triggered inflammatory response in macrophages in vitro. Transcriptomic analysis suggested that exosomes exerted their effects through regulating cell metabolism, differentiation, and inflammation resolution. In vivo, weekly exosome injection into the gingival tissues reduced the tissue destruction and immune cell infiltration in rat ligature-induced periodontitis model. Collectively, these findings suggest that hBMSC-derived exosomes can potentially be used as a host modulation agent in the management of periodontitis.

Membrane exposure is a widely reported and relatively common complication in Guided Bone Regeneration (GBR) procedures. The introduction of micro-porous dPTFE barriers, which are impervious to bacterial cells, could reduce the technique sensitivity to membrane exposure, even if there are no studies investigating the potential passage of bacterial metabolites through the barrier. Aim of this study was the in vitro evaluation of the permeability of three different GBR membranes (dPTFE, native and cross-linked collagen membranes) to Porphyromonas gingivalis; in those cases, where bacterial penetration could not be observed, another purpose was the analysis of the viability and differentiation capability of an osteosarcoma (U2OS) cell line in presence of bacteria eluate obtained through membrane percolation. A system leading to the percolation of P. gingivalis broth culture through the experimental membranes was arranged to assess the permeability to bacteria after 24 and 72 h of incubation. The obtained solution was then added to U2OS cell cultures which underwent, after 10 days of incubation, MTT and red alizarin essays. The dPTFE membrane showed resistance to bacterial penetration, while both types of collagen membranes were crossed by P. gingivalis after 24 h. The bacteria eluate filtered through dPTFE membrane didn't show any toxicity on U2OS cells. Results of this study demonstrate that dPTFE membranes can contrast the penetration of both P. gingivalis and its metabolites toxic for osteoblast-like cells. The toxicity analysis was not possible for the collagen membranes, since permeability to bacterial cells was observed within the first period of incubation.

Gut dysbiosis induces 'leaky gut,' a condition associated with diabetes, NASH, and various auto-immune diseases. Porphyromonas gingivalis is a periodontopathic bacterium which causes periodontal tissue breakdown, and often enters the systemic blood flow. Oral administration of P. gingivalis induced gut dysbiosis in mice model, but no systemic administration of P. gingivalis has been reported thus far. In the present study, we investigated the effect of P. gingivalis-derived lipopolysaccharide (Pg-LPS) on the intestinal flora of our established mouse model. Eight-week-old C57BL/6J mice were intraperitoneally administered Pg-LPS. Three months later, DNA was extracted from stool, and RNA from the small and large intestines. After euthanizing the mice, pathological sections of the intestinal tract were prepared and stained with hematoxylin and eosin (HE). Tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, and IL-6 expression levels were evaluated using quantitative PCR. 16S rRNA gene PCR amplicon analysis data were acquired using NGS. Microbial diversity and composition were analyzed using Quantitative Insights into Microbial Ecology 2. Furthermore, alterations in microbial function were performed by PICRUSt2. No significant inflammatory changes were observed in the HE. No significant differences in the mRNA levels of IL-1β, IL-6, and TNF-α were observed between the groups. Pg-LPS administration decreased the abundance of Allobacterium in the gut. A predictive metagenomic analysis by PICRUSt2 and STAMP showed that 47 pathways increased and 17 pathways decreased after Pg-LPS administration. Systemic application of periodontal pathogens may cause changes in the intestinal flora which may affect the physiological functions of the intestinal tract.

Oral and esophageal squamous cell carcinomas harbor a diverse microbiome that differs compositionally from precancerous and healthy tissues. Though causality is yet to be definitively established, emerging trends implicate periodontal pathogens such as Porphyromonas gingivalis as associated with the cancerous state. Moreover, infection with P. gingivalis correlates with a poor prognosis, and P. gingivalis is oncopathogenic in animal models. Mechanistically, properties of P. gingivalis that have been established in vitro and could promote tumor development include induction of a dysbiotic inflammatory microenvironment, inhibition of apoptosis, increased cell proliferation, enhanced angiogenesis, activation of epithelial-to-mesenchymal transition, and production of carcinogenic metabolites. The microbial community context is also relevant to oncopathogenicity, and consortia of P. gingivalis and Fusobacterium nucleatum are synergistically pathogenic in oral cancer models in vivo. In contrast, oral streptococci, such as Streptococcus gordonii, can antagonize protumorigenic epithelial cell phenotypes induced by P. gingivalis, indicating functionally specialized roles for bacteria in oncogenic communities. Consistent with the notion of the bacterial community constituting the etiologic unit, metatranscriptomic data indicate that functional, rather than compositional, properties of the tumor-associated communities have more relevance to cancer development. A consistent association of P. gingivalis with oral and orodigestive carcinoma could have diagnostic potential for early detection of these conditions that have a high incidence and low survival rates.

The link between oral health and adverse pregnancy outcomes has been suggested by numerous epidemiological studies. More recent studies indicate the relationship between severity of periodontal disease and adverse pregnancy outcomes. Two virulence mechanisms are proposed: direct invasion of oral microorganisms or their components into the fetal-placenta unit and inflammatory mediators produced in the oral cavity affecting the fetal-placenta unit. While interventional periodontal therapy still yielded contradictory results, animal studies suggest that maternal supplementation of omega-3 fatty acids protects the fetus by suppressing inflammation as well as bacteria proliferation in the placenta. This article reviews the recent epidemiological, mechanistic, interventional, and therapeutic studies of oral health and adverse pregnancy outcomes.

The effect of electronic cigarette (e-cigarette) smoking, especially its long-term impact on oral health, is poorly understood. Here, we conducted a longitudinal clinical study with two study visits, 6 months apart, to investigate the effect of e-cigarette use on the bacterial community structure in the saliva of 101 periodontitis patients. Our data demonstrated that e-cigarette use altered the oral microbiome in periodontitis patients, enriching members of the Filifactor, Treponema, and Fusobacterium taxa. For patients at the same periodontal disease stage, cigarette smokers and e-cigarette smokers shared more similarities in their oral bacterial composition. E-cigarette smoking may have a similar potential as cigarette smoking at altering the bacterial composition of saliva over time, leading to an increase in the relative abundance of periodontal disease-associated pathogens such as Porphyromonas gingivalis and Fusobacterium nucleatum. The correlation analysis showed that certain genera, such as Dialister, Selenomonas, and Leptotrichia in the e-cigarette smoking group, were positively correlated with the levels of proinflammatory cytokines, including IFN-γ, IL-1β, and TNF-α. E-cigarette use was also associated with elevated levels of proinflammatory cytokines such as IFN-γ and TNF-α, which contribute to oral microbiome dysbiosis and advanced disease state.

Tolerance is defined to be a hyporesponsive state following repeated stimulations with bacteria or their virulence factors and has potential impacts on the development of periodontitis. Recently, macrophages have been reported to release chromatin and antimicrobial peptides to form extracellular traps upon bacterial or chemical stimulations. Thus, we explored the roles and mechanisms of tolerance induced by Porphyromonas gingivalis (P. gingivalis) in macrophage extracellular traps (METs). Tolerance in peritoneal macrophages from mice was triggered by repeated P. gingivalis stimulation. METs were observed using fluorescence microscopy, and the levels of extracellular DNA were determined by microplate reader assays. The expression of p-RAF, p-MEK, and p-ERK was examined by Western blot, and reactive oxygen species (ROS) production was explored using flow cytometry. Moreover, the levels of intracellular Ca

Recent epidemiological studies have shown that inflammatory bowel disease is associated with periodontal disease. The oral–gut microbiota axis is a potential mechanism intersecting the two diseases. Porphyromonas gingivalis is currently considered a keystone oral pathogen involved in periodontal disease pathogenesis and disease progression. Recent studies have shown that oral ingestion of P. gingivalis leads to intestinal inflammation. However, the molecular underpinnings of P. gingivalis-mediated gut inflammation have remained elusive. In this study, we show that the oral administration of P. gingivalis indeed leads to ileal inflammation and alteration in gut microbiota with significant reduction in bacterial alpha diversity despite the absence of P. gingivalis in the lower gastrointestinal tract. Utilizing an antibiotic-conditioned mouse model, cecal microbiota transfer experiments were performed to demonstrate that P. gingivalis-induced dysbiotic gut microbiota is sufficient to reproduce gut pathology. Furthermore, we observed a significant expansion in small intestinal lamina propria IL9(+) CD4(+) T cells, which was negatively correlated with both bacterial and fungal alpha diversity, signifying that P. gingivalis-mediated intestinal inflammation may be due to the subsequent loss of gut microbial diversity. Finally, we detected changes in gene expression related to gut epithelial barrier function, showing the potential downstream effect of intestinal IL9(+)CD4(+) T-cell induction. This study for the first time showed the mechanism behind P. gingivalis-mediated intestinal inflammation where P. gingivalis indirectly induces intestinal IL9(+) CD4(+) T cells and inflammation by altering the gut microbiota. Understanding the mechanism of P. gingivalis-mediated intestinal inflammation may lead to the development of novel therapeutic approaches to alleviate the morbidity from inflammatory bowel disease patients with periodontal disease.

Objectives Peri-implantitis is a destructive inflammatory process that affects the soft and hard tissues around dental implants. porphyromonas gingivalis, an anaerobic gram-negative bacterium, appears to be the main culprit. Since there is no efficient and specific vaccine to treat peri-implantitis, the goal of our research has been to develop a multi-epitope vaccination utilizing an immunoinformatics approach that targeted P. gingivalis type I fim A. Materials and methods P. gingivalis peptides 6JKZ and 6KMF are suitable for vaccine development. B- and T-cell epitopes from 6KMF and 6JKZ were detected and evaluated based on critical factors to produce a multi-epitope vaccine construct. It was assessed based on allergenicity, antigenicity, stability. The vaccine's dual major histocompatibility complex (MHC-I and MHC-II) binding epitopes allowed it to reach a larger population. P. gingivalis fimbriae induce immune subversion through TLR -CXCR4 receptor complex pathway. The ClusPro 2.0 server was used to do the molecular docking using TLR2 - CXCR4 and vaccine epitopes as receptor and ligand respectively. Results The designed vaccine was non-allergenic and had a high antigenicity, solubility, and stability. The 3D structure of the vaccine revealed strong interaction with CXCR4(TLR2) using molecular docking. The vaccine-CXCR4 interface was more consistent, possibly because the vaccination has a higher affinity for the CXCR4-TLR2 complex. Conclusion This study details the vaccine's distinct and sustained interaction with the CXCR4(TLR2) immunological receptor and its consistent and effective utterance in the bacterial system. As a result, our vaccine formulation will evoke a significant memory response and induce an adaptive immune response against P. gingivalis.

Periodontitis is a chronic inflammatory disease of gum resulting from Porphyromonas gingivalis infectious at periodontal pockets. In situ forming gel (ISG) effectively delivers the antimicrobial agents to this targeted site. This study was to develop the dimethyl sulfoxide (DMSO) removal-based ISGs of Eudragit®L and their physicochemical properties were evaluated including the viscosity, rheological behavior, in vitro matrix formation, in vitro doxycycline hyclate (DH) release and antimicrobial activities. The ISGs showed the Newtonian flow which an increase in Eudragit®L amount enhanced a viscosity. They transformed into an opaque gel after exposure a simulated crevicular fluid and modulated the DH release longer than 3 days. The percentage of drug release from DMSO removal-based ISG containing 10, 15, 20 and 25% w/w of Eudragit®L was 95.9, 90.5, 79.8 and 70.0, respectively. Thus, DH release depended on the amount of Eudragit®L loading and corresponded with the polymeric matrix formation. The high Eudragit®L loading formulation retarded notably on the solvent removal owing to a thicker gel barrier. The DH-loaded in situ solvent removal-based Eudragit®L/ DMSO forming gels presented the efficient antimicrobial activities against Staphylococcus aureus, Escherichia coli, Candida albicans and Porphyromonas gingivalis. Therefore, Eudragit®L/DMSO ISG exhibited as a potential periodontal pocket drug delivery system based on solvent removal mechanism.

The concept of time to place conversion makes using a continuous flow polymerase chain reaction (CF-PCR) microfluidic chip an ideal way to reduce the time required for amplification of target genes; however, it also brings about low throughput amplicons. Although multiplex PCR can simultaneously amplify more than one target gene in the chip, it may easily induce false positives because of cross-reactions. To circumvent this problem, we herein fabricated a microfluidic system based on a CF-PCR array microfluidic chip. By dividing the chip into three parts, we successfully amplified target genes of

Background/purpose Bacterial biofilms formed on the surface of tissues and biomaterials are major causes of chronic infections in humans. Among them, Porphyromonas gingivalis (P. gingivalis) and Prevotella intermedia (P. intermedia) are anaerobic pathogens causing dental infections associated with periodontitis. In this study, we evaluated the killing effect and underlying mechanisms of direct current (DC) as an antimicrobial method in vitro. Materials and methods We chose P. gingivalis and P. intermedia in different states to make comparisons of the killing effect of DC. By viable bacteria counting, fluorescent live/dead staining, reactive oxygen species (ROS) assay, addition of ROS scavenger DMTU and mRNA expression assay of ROS scavenging genes, the role of ROS in the killing effect was explored. Results The planktonic and biofilm states of two bacteria could be effectively killed by low-intensity DC. For the killing effect of 1000 μA DC, there were significant differences whether on planktonic P. gingivalis and P. intermedia (mean killing values: 2.40 vs 2.62 log10 CFU/mL) or on biofilm state of those (mean killing values: 0.63 vs 0.98 log10 CFU/mL). 1000 μA DC greatly induced ROS production and the mRNA expression of ROS scavenging genes. DMTU could partially decrease the killing values of DC and downregulate corresponding gene’s expression. Conclusion 1000 μA DC can kill P. gingivalis and P. intermedia in two states by promoting overproduction of ROS, and P. intermedia is more sensitive to DC than P. gingivalis. These findings indicate low-intensity DC may be a promising approach in treating periodontal infections.

Background: Porphyromonas gingivalis (P. gingivalis) is a pathogenic bacterium widely present in subgingival plaques of patients with periodontitis. It induces periodontitis with bone loss as its main feature by changing the number and composition of symbiotic microorganisms, as well as inducing the natural immune response of the host. However, the mechanism of the latter remains unclear. Objective: This study aims to investigate the effect of P. gingivalis lipopolysaccharide (LPS) on regulatory B cells (Breg) in the occurrence and development of periodontitis. Method: We detected the mRNA levels of IL-10 in B cells under the stimulation of P. gingivalis LPS and/or E. coli LPS, distinguished IL-10-producing cells from different B cell subgroups using flow cytometry. Through toll-like receptor (TLR) knockout mice, the role of TLR2 and TLR4 in this process was also evaluated. Results: Results showed that P. gingivalis stimulated B cells to produce IL-10 via TLR2/4. CD5+B1 subset is the main source of IL-10+Breg cell. Under P. gingivalis LPS stimulation, CD5+IgM+CD93-IL-10+B cell subset increased significantly, which was regulated through TLR2/ 4. Conclusion: The results of this study provides new insights into the immunopathogenic mechanism of P. gingivalis, preliminarily discussed the effect of P. gingivalis on the production of Breg, and present a theoretical foundation for subsequent investigations on the occurrence and development of periodontitis.

Interactions between gingival fibroblasts (GFs) and oral pathogens contribute to the chronicity of inflammation in periodontitis. Epigenetic changes in DNA methylation are involved in periodontitis pathogenesis, and recent studies indicate that DNA methyltransferase (DNMT) inhibitors may protect against epithelial barrier disruption and bone resorption. To assess the impact of DNMT inhibition on GFs, cells were cultured with decitabine (5-aza-2’-deoxycytidine, DAC) for 12 days to induce DNA hypomethylation. We observed several potentially detrimental effects of DAC on GF biological functions. First, extended treatment with DAC reduced GF proliferation and induced necrotic cell death. Second, DAC amplified Porphyromonas gingivalis- and cytokine-induced expression and secretion of the chemokine CCL20 and several matrix metalloproteinases (MMPs), including MMP1, MMP9, and MMP13. Similar pro-inflammatory effects of DAC were observed in periodontal ligament fibroblasts. Third, DAC upregulated intercellular adhesion molecule-1 (ICAM-1), which was associated with increased P. gingivalis adherence to GFs and may contribute to bacterial dissemination. Finally, analysis of DAC-induced genes identified by RNA sequencing revealed increased expression of CCL20, CCL5, CCL8, CCL13, TNF, IL1A, IL18, IL33, and CSF3, and showed that the most affected processes were related to immune and inflammatory responses. In contrast, the genes downregulated by DAC were associated with extracellular matrix and collagen fibril organization. Our observations demonstrate that studies of DNMT inhibitors provide important insights into the role of DNA methylation in cells involved in periodontitis pathogenesis. However, the therapeutic potential of hypomethylating agents in periodontal disease may be limited due to their cytotoxic effects on fibroblast populations and stimulation of pro-inflammatory pathways.

It has been reported that GroEL, a heat shock protein (HSP) produced by the representative periodontopathogenic bacterium, Porphyromonas gingivalis, induces inflammation-induced osteoclastogenesis and promotes alveolar bone resorption. In this study, we demonstrated the efficacy of a mucosal vaccine targeting GroEL against bone resorption induced by P. gingivalis. Female BALB/c mice received sublingual CpG oligodeoxynucleotide as an adjuvant with recombinant GroEL (rGroEL) prior to P. gingivalis exposure. Animals were euthanized 30 days after P. gingivalis inoculation. Sublingual immunization (SLI) with rGroEL elicited significant rGroEL-specific serum immunoglobulin (Ig)G and salivary IgA antibody (Ab) responses, and these responses were sustained for approximately 1 year. Interestingly, 10-fold more GroEL-specific IgA Ab-producing cells were detected in the submandibular glands (SMGs) than in the spleen. Antigen (Ag)-specific cells isolated from the spleen and SMGs induced significantly higher levels of IFN-γ expression after Ag restimulation in vitro. Flow cytometry illustrated that the frequency of CD11b

Mesenchymal stem cells (MSCs) are increasingly used in tissue regeneration, not only because of their multilineage differentiation ability, but also because of their immunomodulatory function, which allows them to play a role in the inflammatory milieu, especially in periodontitis. Porphyromonas gingivalis (P. gingivalis) is an important pathogen associated with the progression of periodontitis. Heterogeneous MSC sources show differences in their inflammatory-immune responsiveness and osteogenesis capabilities when exposed to P. gingivalis and its virulence factors. This article reviews the promoted inflammatory and immune responses of periodontal ligament stem cells, which are potential pitfalls in bone regeneration. MSCs from other sources showed contradictory inflammatory and immune reactions in the few studies on this topic. We also summarize the mechanisms involved in the inflammatory, immune responses and osteogenic potential of MSCs exposed to P. gingivalis and its virulence factors to inform an improved utilization of MSCs in regenerative therapies for periodontitis.

The human body contains more than 100 trillion microorganisms, including the oral cavity, the skin, and the gastrointestinal tract. After the gastrointestinal tract, the oral cavity harbors one of the most diverse microbial communities within the human body and harbors more than 770 species of bacteria. The composition of the oral and gut microbiomes is quite different, but there may be a microbiological link between the two mucosal sites during the course of disease. More studies indicate that oral bacteria can disseminate to the distal gut via enteral or hematogenous routes. This is mostly obvious in periodontitis, where specific bacteria, such as Fusobacterium nucleatum and Porphyromonas gingivalis, show this pathogenic feature. The translocation of oral microbes to the gut may give rise to a variety of gastrointestinal diseases, including colorectal cancer. However, the precise role that oral microbe play in colorectal cancer has not been fully illustrated. Here, we summarize the current researches on possible pathways of ectopic gut colonization by oral bacteria and their possible contribution to the pathogenesis of colorectal cancer. Understanding the correlation of the oral-to-gut microbial axis in the pathogenesis of colorectal cancer will contribute to precise diagnosis and effective treatment.

The leading cause of dementia is Alzheimer’s disease (AD), which affects millions worldwide. Aging populations can foretell the worsening burden of the disease in the future. AD is characterised by the following hallmark pathologies: amyloid-β over-production and deposition, abnormal hyperphosphorylation of tau leading to the formation of neurofibrillary tangles, and neuroinflammation. Many potential treatments fail in clinical trials, suggesting that present theories are outdated or lead to therapeutic dead-ends. A gum disease-causing species of bacteria, Porphyromonas gingivalis, is being increasingly linked with AD, given the ubiquity of gum disease amongst older populations, and studies have revealed that the bacteria causes and exacerbates AD pathology both in vitro and in vivo. P. gingivalis produce many neurotoxic molecules, including gingipain enzymes, lipopolysaccharide and phosphoglycerol dihydroceramides, and all of these have been shown to affect AD pathologies. Numerous mechanisms by which these neurotoxic species reach the brain have been proposed, and one of these is the bacteria’s use of outer membrane vesicles. This review presents the present evidence of the effects of P. gingivalis and its outer membrane vesicles, gingipains, lipopolysaccharide and phosphoglycerol dihydroceramides, on neurodegeneration in neuronal cultures, mice models and post-mortem studies, and determines how this evidence can be used to develop new treatments for AD.

Introduction Gingivitis is an oral condition characterized by inflammation and bleeding of the gingiva (gums), largely caused by Porphyromonas gingivalis. Oral hygiene options for controlling P. gingivalis include mouthwash containing Commiphora myrrha (myrrh), which has been shown to be effective against the microbe. Silver nanoparticles (SN) have been studied for their antibacterial effect in different oral health applications, including mouthwash. This was an in vitro laboratory study of the anti-microbial actions of myrrh and SN against P. gingivalis. Methods We compared the anti-microbial properties against P. gingivalis of four solutions: a) placebo solution, b) myrrh solution (MS), c) MS mixed with silver nanoparticles (MSN), and d) SN suspension alone. Sixteen agar plates were divided into four groups of four plates, and each group was treated with one of the solutions/suspensions. The solution/suspension was administered on the agar disc diffusion method, and inhibition zones (IZs) were measured after 24 (time 1), 48 (time 2), and 72 h (time 3). To characterize MSN and SN, Fourier-transform infrared spectroscopy (FT-IR) was used. UV–Vis spectroscopy and energy dispersive X-ray (EDX) were used to further characterize MSN. Results After 24 h, the median IZ for the MS plates was 16 mm, and the median IZ for MSN plates was 15 mm. At time 2, the MS median IZ was 15 mm, but the MSN median IZ increased to 18 mm, and the interquartile ranges (IQRs) did not overlap. At time 3, the median IZs was similar again, with MSN and MS having IZs of 16 mm and 15 mm, respectively. SN alone showed no anti-microbial activity. Conclusions Our findings show that MSN displayed superior anti-microbial activity against P. gingivalis compared to MS and SN after 48 h of incubation, but not after 24 h. Also, the increased anti-microbial activity had ceased by 72 h.

Background As the global aging population is rapidly advancing, recognizing the full potential of periodontal disease (PD) in the onset or progression of Alzheimer's disease (AD) is important for reducing geriatric morbidity. This review explores the possible role of PD in the pathogenesis of AD, as the pathological mechanisms underlying AD are the most well-studied among all types of dementia. The investigation was conducted using the electronic academic databases PubMed and ScienceDirect, employing a combination of keywords “periodontal disease,” “periodontitis,” “Alzheimer's disease,” “dementia,” and “Porphyromonas gingivalis.” After applying the selection and eligibility criteria and removing overlaps, from an initial search finding of 5933 studies, 11 were finally included for qualitative analysis. Highlight The inflammatory reaction induced by oral pathogenic bacteria related to PD, through complex pathways, may exacerbate inflammation in the central nervous system, thereby contributing to the progression of AD. Conclusion Maintenance of adequate oral hygiene in patients diagnosed with AD is significant because they suffer from a gradual loss of manual dexterity as the disease advances. Additionally, the evidence presents the potential of systemic inflammation from PD-induced pathogenic bacteria, illustrating the grave cyclical progression of AD.

Plant extracts and phytochemicals having antimicrobial characteristics could be immensely beneficial in medicinal treatments. The present study deals with the effect of Citrus lemon extract over Periodontal pathogens which are primary etiologic factors for periodontal diseases. The current study took into account periodontal pathogens such as Prevotella Intermedia, Aggregatibacter Actinomycetemcomitans, and Porphyromonas Gingivalis. Chlorhexidine is a gold standard antimicrobial agent with a wide antibacterial activity that is commonly used for chemical plaque management. When used for an extended period, however, chlorhexidine is known to stain. As a result, the alternatives are to be explored such as herbal-based agents that can be used regularly. Using the microdilution process and the culture method, the antibacterial effect of citrus lemon extract against periodontal pathogens was assessed using the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and zone of inhibition (ZOI). According to the findings of this study, citrus lemon extract can be used as a natural supplement for treatment purposes. Keywords: Antimicrobial, Citrus lemon Extract, Chlorhexidine, Periodontal Pathogens.

The hematopoietic tissue is highly susceptible to stimuli, and inflammation is a major modulator. One particular source for this inflammatory burden is periodontitis. We revisit how periodontal infection may modulate the activity of the bone marrow, the fate of hematopoietic stem cells, and its systemic consequences. We also examine periodontal manifestations of particular blood disorders. Herein, we provide a glimpse of the available knowledge and discuss gaps that may be explored in the future. Recent studies have demonstrated that Porphyromonas gingivalis governs osteoclastogenic differentiation by regulating nuclear factor-kappa B ligand and inhibiting noncommitted osteoclasts precursors. This governed cell population exhibits an antigen-specific T cell immune-suppressive activity benefiting the persistence of periodontal infection and compromising the host immune response. The persistence of this low-grade inflammation together with this particular cell population enhances osteoclastogenic precursors from myeloid-derived suppressor cells, increasing the age-associated bone loss in mice. Periodontitis patients exhibit serum biomarkers of anemia, attributed to a state of anemia of inflammation. In other words, the production of hepcidin through the action of cytokines results in higher iron trapping inside macrophages and liver cells ant his may shorten erythrocyte survival. Another possible hypothesis to explain this link is the inflammatory suppression of erythropoietic activity, through the levels of erythropoietin. Periodontal therapy is effective in reducing leukocytosis, but evidence is to scarce regarding red and platelet lineages. Furthermore, periodontitis patients suffering from white blood cells disorders seem more prone to severe periodontal destruction given the pathophysiology of periodontitis and the immune role of leukocyte cells. The systemic inflammatory burden of periodontitis modulates the fate of differentiation of particular bone marrow and interferes with the erythropoietic activity. The impact of periodontal therapy on leukocytosis is robust and based on high quality evidence-based estimates, though its influence on erythrocytic and platelet levels is still limited. The existence of a greater predisposition to periodontal disease in blood disorders is not consensual.

Introduction. The associative role of the bacterial factor in the development of both primary malignant tumors of the oral mucosa and relapses is being actively discussed today. In the article published earlier, we have already described the possible mechanisms of action of periodontopathogenic microflora and its connection with the development of squamous cell carcinoma of the oral mucosa through cell proliferation, intracellular accumulation of pathogen, DNA replication and affect the signaling pathways of MARK (mitogen-activated protein kinase).Objective – to analyze the impact of periodontal pathogens on the risk of oral squamous cell carcinoma and its recurrence, as well as to evaluate the role of polymerase chain reaction and bacterial culture in the diagnosis of squamous cell carcinoma.Materials and methods. This study included 35 patients with stage Т3–4 squamous cell carcinoma, whose tumor tissue samples were tested for periodontal pathogens using culture and PCR. We analyzed 5 paraffin-embedded and 30 frozen tissue blocks from newly diagnosed (n = 15) and re-treatment (n = 15) patients.Results. We found that PCR was more sensitive than culture for the detection of possible etiological agents and predictors of squamous cell carcinoma (including Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola) (р Tannerella forsythia and Treponema denticola were detected only using PCR, whereas all cultures were negative. However, conventional culture proved to be more effective than PCR for the detection of Prevotella intermedia. Between 3 % and 100 % of newly diagnosed patients tested positive for Treponema denticola and some other periodontal pathogens (PCR) developed relapses, whereas among re-treatment patients, this proportion was 66.6 %.Conclusion. The combination of the culture method and the polymerase chain reaction method in the study of periodontopathogenic microflora has shown high efficiency in identifying possible predictors of squamous cell carcinoma of the oral mucosa and in preventing the development of chronic infectious periodontal diseases.

In line with the strong association between periodontitis and Alzheimer’s disease (AD) clinically, preclinical studies have shown that systemic exposure to Porphyromonas gingivalis (Pg) initiates AD pathologies. However, the involvement of periodontitis in promoting AD pathologies is unclear. In the present study, we provided evidence that chronic systemic exposure to lipopolysaccharide derived from Pg (PgLPS, 1 mg/kg, daily, intraperitoneally) prompted neuroinflammation and tau hyperphosphorylation in 10-month-old of amyloid precursor protein (APP) knock-in mice, a model of AD, carrying the Swedish and Beyreuther/Iberian mutation (APPNL-F/NL-F). The learning and memory function were assessed using the passive avoidance test. The production of APP, Amyloid (A)β1-42, cytokines, synaptic proteins and the activation of glycogen synthase kinase (GSK)-3β as well as phosphorylation of tau were analyzed by immunohistochemistry, Western blotting or an enzyme-linked immunosorbent assay (ELISA) in the cortex of APPNL-F/NL-F mice. We found that systemic exposure of PgLPS for three consecutive weeks induced learning and memory deficits with significantly reduced postsynaptic density protein (PSD95). Increased hyperphosphorylation of tau in multiple residues, including Ser202, Thr231 and Ser396, but not the accumulation of Aβ1-42 was detected in the neurons of APPNL-F/NL-F mice. Furthermore, PgLPS increased the GSK3β activity by reducing its phosphorylation of the serine residue at position 9 (Ser9) and promoted neuroinflammation by increasing the expression of interleukin-1β (IL-1β) and tumor necrosis factor (TNF-α) while decreasing that of interleukin-10 (IL-10) and transforming growth factor (TGFβ) in the cortex of APPNL-F/NL-F mice. Moreover, the PgLPS-increased GSK3β activity was detected in both microglia and neurons, while the PgLPS-increased TNF-α expression was mainly detected in the microglia in the cortex of APPNL-F/NL-F mice. In in vitro studies, PgLPS (1 µg/ml) stimulation increased the mRNA and protein level of TNF-α in MG6 microglia, which were significantly inhibited by the GSK3β-specific inhibitor TWS119. In contrast, the tau hyperphosphorylation and activation of GSK3β in N2a neurons were enhanced after treatment with conditioned medium from PgLPS-stimulated microglia, which was attenuated after pre-treatment with TNF-α inhibitor. Taken together, these findings indicate that GSK3β is involved in prompting microglia (TNF-α)-dependent tau hyperphosphorylation in neurons, resulting in learning and memory deficits in APPNL-F/NL-F mice without changes in the Aβ expression during chronic systemic exposure to PgLPS. We propose that dampening GSK3β activation may help delay the periodontitis-promoted pathological progression of AD.

Although there is a well-documented link between periodontal disease and heart health, the mechanisms are unclear. Our study indicates that in response to circulating periodontal endotoxins, memory CD8+ T cells are activated, resulting in an acceleration of macrophage-mediated inflammation after MI. Blocking activation of effector CD8+ T cells had no effect on the macrophage numbers or wall thinning at post-MI day 1, indicating that this response was likely due in part to memory CD8+ T cells.

γδ T cells are nonclassical T lymphocytes representing the major T-cell population at epithelial barriers. In the gingiva, γδ T cells are enriched in epithelial regions adjacent to the biofilm and are considered to regulate local immunity to maintain host-biofilm homeostatic interactions. This delicate balance is often disrupted resulting in the development of periodontitis. Previous studies in mice lacking γδ T cells from birth ( Tcrd-/-mice) examined the impact of these cells on ligature-induced periodontitis. Data obtained from those studies proposed either a protective effect or no impact to γδ T cells in this setting. Here, we addressed the role of γδ T cells in periodontitis using the recently developed Tcrd-GDL mice, enabling temporal ablation of γδ T cells. Specifically, the impact of γδ T cells during periodontitis was examined in 2 modalities: the ligature model and the oral infection model in which the pathogen Porphyromonas gingivalis was administrated via successive oral gavages. Ablation of γδ T cells during ligature-induced periodontitis had no impact on innate immune cell recruitment to the ligated gingiva. In addition, the number of osteoclasts and subsequent alveolar bone loss were unaffected. However, γδ T cells play a pathologic role during P. gingivalis infection, and their absence prevented alveolar bone loss. Further analysis revealed that γδ T cells were responsible for the recruitment of neutrophils and monocytes to the gingiva following the exposure to P. gingivalis. γδ T-cell ablation also downregulated osteoclastogenesis and dysregulated long-term immune responses in the gingiva. Collectively, this study demonstrates that whereas γδ T cells are dispensable to periodontitis induced by the ligature model, they play a deleterious role in the oral infection model by facilitating pathogen-induced bone-destructive immune responses. On a broader aspect, this study highlights the complex immunopathologic mechanisms involved in periodontal bone loss.

Periodontitis involves chronic inflammation of the tissues around the teeth caused by plaque and the corresponding immune response. Growth arrest-specific protein 6 (GAS6) and AXL receptor tyrosine kinase (AXL) are known to be involved in inflammatory diseases, while signal transducer and activator of transcription-1 (STAT1) and suppressor of cytokine signaling (SOCS) are related to inflammatory processes. Moreover, miRNA34a directly targets AXL to regulate the AXL expression. However, the specific roles of GAS6 and AXL in periodontitis remain unclear. This study was designed to explore the effect and mechanism of AXL on the expression of inflammatory cytokines induced by Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS) in human periodontal ligament cells (hPDLCs). The effects of different concentrations of P. gingivalis LPS on the expression of GAS6/AXL in hPDLCs were observed. Additionally, the effect of LPS on AXL was investigated by transfection of the miRNA34a inhibitor. AXL was knocked down or overexpressed to observe the release of inflammatory cytokines interleukin- (IL-) 8 and IL-6. The results showed that the expression levels of GAS6 and AXL decreased after P. gingivalis LPS infection. Transfection of a miR-34a inhibitor to hPDLCs demonstrated a role of miR-34a in the downregulation of AXL expression induced by LPS. Moreover, AXL knockdown or overexpression influencing the expression of IL-8 and IL-6 was investigated under LPS stimulation. AXL knockdown decreased the expression of STAT1 and SOCS1/3. Overall, these results demonstrate that AXL inhibits the expression of LPS-induced inflammatory cytokines in hPDLCs and that STAT1 and SOCS1/3 are involved in the regulation of inflammation by GAS6/AXL.