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Biofilm Jun 2024Restorative dental materials can frequently extend below the gingival margin, serving as a potential haven for microbial colonization, and altering the local oral...
Restorative dental materials can frequently extend below the gingival margin, serving as a potential haven for microbial colonization, and altering the local oral microbiome to ignite infection. However, the contribution of dental materials on driving changes of the composition of the subgingival microbiome is under-investigated. This study evaluated the microbiome-modulating properties of three biomaterials, namely resin dental composites (COM), antimicrobial piezoelectric composites (BTO), and hydroxyapatite (HA), using an optimized subgingival microbiome model derived from patients with periodontal disease. Dental materials were subjected to static or cyclic loading (mastication forces) during biofilm growth. Microbiome composition was assessed by 16S rRNA gene sequencing. Dysbiosis was measured in terms of subgingival microbial dysbiosis index (SMDI). Biomaterials subjected to cyclic masticatory loads were associated with enhanced biofilm viability except on the antibacterial composite. Biomaterials held static were associated with increased biofilm biomass, especially on HA surfaces. Overall, the microbiome richness (Chao index) was similar for all the biomaterials and loading conditions. However, the microbiome diversity (Shannon index) for the HA beams was significantly different than both composites. In addition, beta diversity analysis revealed significant differences between composites and HA biomaterials, and between both loading conditions (static and cyclic). Under static conditions, microbiomes formed over HA surfaces resulted in increased dysbiosis compared to composites through the enrichment of periopathogens, including , , and spp., and depletion of commensals such as and spp. Interestingly, cyclic loading reversed the dysbiosis of microbiomes formed over HA (depletion of periopathogenes) but increased the dysbiosis of microbiomes formed over composites (enrichment of and ). Comparison of species formed on both composites (control and antibacterial) showed some differences. Commercial composites enriched spp. and depleted . Piezoelectric composites effectively controlled the microbiome viability without significantly impacting the species abundance. Findings of this work open new understandings of the effects of different biomaterials on the modulation of oral biofilms and the relationship with oral subgingival infections.
PubMed: 38800100
DOI: 10.1016/j.bioflm.2024.100199 -
Journal of Clinical Biochemistry and... May 2024The study aimed to explore the impact and potential mechanism of Porphyromonas gingivalis lipopolysaccharide (LPS-PG) on esophageal squamous cell carcinoma (ESCC) cell...
The study aimed to explore the impact and potential mechanism of Porphyromonas gingivalis lipopolysaccharide (LPS-PG) on esophageal squamous cell carcinoma (ESCC) cell behavior. ESCC cells from the Shanghai Cell Bank were used, and TLR4, MYD88, and JNK interference vectors were constructed using adenovirus. The cells were divided into six groups: Control, Model, Model + radiotherapy + LPS-PG, Model + radiotherapy + 3-MA, Model + radiotherapy + LPS-PG + 3-MA, and Model + radiotherapy. Various radiation doses were applied to determine the optimal dose, and a radioresistant ESCC cell model was established and verified. CCK8 assay measured cell proliferation, flow cytometry and Hoechst 33258 assay assessed apoptosis, and acridine orange fluorescence staining tested autophagy. Western blot analyzed the expression of LC3II, ATG7, P62, and p-ULK1. Initially, CCK8 and acridine orange fluorescence staining identified optimal LPS-PG intervention conditions. Results revealed that 10 ng/ml LPS-PG for 12 h was optimal. LPS-PG increased autophagy activity, while 3-MA decreased it. LPS-PG + 3-MA group exhibited reduced autophagy. LPS-PG promoted proliferation and autophagy, inhibiting apoptosis in radioresistant ESCCs. LPS-PG regulated TLR4/MYD88/JNK pathway, enhancing ESCC autophagy, proliferation, and radioresistance. In conclusion, LPS-PG, through the TLR4/MYD88/JNK pathway, promotes ESCC proliferation, inhibits apoptosis, and enhances radioresistance by inducing autophagy.
PubMed: 38799145
DOI: 10.3164/jcbn.22-138 -
BioRxiv : the Preprint Server For... May 2024The Type-IX secretion system (T9SS) is a nanomachinery utilized by bacterial pathogens to facilitate infection. The system is regulated by a signaling cascade serving as...
The Type-IX secretion system (T9SS) is a nanomachinery utilized by bacterial pathogens to facilitate infection. The system is regulated by a signaling cascade serving as its activation switch. A pivotal member in this cascade, the response regulator protein PorX, represents a promising drug target to prevent the secretion of virulence factors. Here, we provide a comprehensive characterization of PorX both and . First, our structural studies revealed PorX harbours a unique enzymatic effector domain, which, surprisingly, shares structural similarities with the alkaline phosphatase superfamily, involved in nucleotide and lipid signaling pathways. Importantly, such pathways have not been associated with the T9SS until now. Enzymatic characterization of PorX's effector domain revealed a zinc-dependent phosphodiesterase activity, with active site dimensions suitable to accommodate a large substrate. Unlike typical response regulators that dimerize via their receiver domain upon phosphorylation, we found that zinc can also induce conformational changes and promote PorX's dimerization via an unexpected interface. These findings suggest that PorX can serve as a cellular zinc sensor, broadening our understanding of its regulatory mechanisms. Despite the strict conservation of PorX in T9SS-utilizing bacteria, we demonstrate that PorX is essential for virulence factors secretion in and affects metabolic enzymes secretion in the non-pathogenic , but not for the secretion of gliding adhesins. Overall, this study advances our structural and functional understanding of PorX, highlighting its potential as a druggable target for intervention strategies aimed at disrupting the T9SS and mitigating virulence in pathogenic species.
PubMed: 38798656
DOI: 10.1101/2024.05.15.594396 -
BioRxiv : the Preprint Server For... May 2024Oyster reefs are invaluable ecosystems that provide a wide array of critical ecosystem services, including water filtration, coastal protection, and habitat provision...
Oyster reefs are invaluable ecosystems that provide a wide array of critical ecosystem services, including water filtration, coastal protection, and habitat provision for various marine species. However, these essential habitats face escalating threats from climate change and anthropogenic stressors. To combat these challenges, numerous oyster restoration initiatives have been undertaken, representing a global effort to preserve and restore these vital ecosystems. A significant, yet poorly understood, component of oyster reefs is the microbial communities. These communities account for a substantial proportion of marine reefs and are pivotal in driving key biogeochemical processes. Particularly, the environmental microbiome plays a crucial role in supporting the health and resilience of oyster populations. In our study, we sought to shed light on the microbiome within oyster reef ecosystems by characterizing the abundance, and diversity of microorganisms in the soil, biofilm, and oysters in 4 sites using a combinatorial approach to identify differentially abundant microbes by sample type and by sampling location. Our investigation revealed distinct microbial taxa in oysters, sediment and biofilm. The maximum Shannon Index indicated a slightly increased diversity in Heron's Head (5.47), followed by Brickyard park (5.35), Dunphy Park (5.17) and Point Pinole (4.85). This is likely to be driven by significantly higher oyster mortality observed at Point Pinole during routine monitoring and restoration efforts. Interestingly and were positively associated with the biofilm. Yet we have limited understanding of their beneficial and/or detrimental implications to oyster growth and survival. By unraveling the intricate relationships in microbial composition across an oyster reef, our study contributes to advancing the knowledge needed to support effective oyster reef conservation and restoration efforts.
PubMed: 38798377
DOI: 10.1101/2024.05.15.594453 -
Clinical and Experimental Dental... Jun 2024This study aimed to evaluate the impact of silver nanoparticles (AgNPs) synthesized from propolis on the formation of Porphyromonas gingivalis biofilms.
OBJECTIVE
This study aimed to evaluate the impact of silver nanoparticles (AgNPs) synthesized from propolis on the formation of Porphyromonas gingivalis biofilms.
MATERIAL AND METHODS
AgNPs were synthesized from propolis, and their inhibitory effect on P. gingivalis biofilm formation was assessed. Different concentrations of AgNPs (0.1%, 0.3%, and 0.5%) were tested to determine the dose-dependent antibacterial activity.
RESULTS
The results of this study indicated that AgNPs exhibited an inhibitory effect on P. gingivalis biofilm formation. The antibacterial activity of AgNPs was dose-dependent, with concentrations of 0.1%, 0.3%, and 0.5% showing effectiveness. Notably, the concentration of 0.5% demonstrated the most significant anti-biofilm formation activity.
CONCLUSION
The results of this study suggest that AgNPs synthesized from propolis have potential as an effective option for enhancing periodontal treatment outcomes. The inhibitory effect of AgNPs on P. gingivalis biofilm formation highlights their potential as alternative antimicrobial agents in the management of periodontal diseases.
Topics: Porphyromonas gingivalis; Biofilms; Silver; Metal Nanoparticles; Anti-Bacterial Agents; Green Chemistry Technology; Propolis; Microbial Sensitivity Tests; Dose-Response Relationship, Drug; Humans
PubMed: 38798089
DOI: 10.1002/cre2.887 -
BMC Oral Health May 2024The oral microbiome plays an essential role in maintaining oral homeostasis and health; smoking significantly affects it, leading to microbial dysbiosis. The study aims...
BACKGROUND
The oral microbiome plays an essential role in maintaining oral homeostasis and health; smoking significantly affects it, leading to microbial dysbiosis. The study aims to investigate changes in the oral microbiome composition of smokers in the Qatari population and establish a correlation with lipid biomarkers.
METHODS
The oral microbiota was profiled from saliva samples of 200 smokers and 100 non-smokers in the Qatari population, and 16s rRNA V3-V4 region were sequenced using the Illumina MiSeq platform. The operational taxonomic units (OTUs) were clustered using QIIME and the statistical analysis was performed by R.
RESULTS
Non-smokers exhibited a more diverse microbiome, with significant alpha and beta diversity differences between the non-smoker and smoker groups. Smokers had a higher abundance of Firmicutes, Bacteroidota, Actinobacteriota, Patescibacteria, and Proteobacteria at the phylum level and of Streptococcus, Prevotella, Veillonella, TM7x, and Porphyromonas at the genus level. In contrast, non-smokers had more Bacteroidota, Firmicutes, Proteobacteria, Fusobacteriota, and Patescibacteria at the phylum level, and Prevotella, Streptococcus, Veillonella, Porphromonas, and Neisseria at the genus level. Notably, Streptococcus was significantly positively correlated with LDL and negatively correlated with HDL. Additionally, Streptococcus salivarius, within the genus Streptococcus, was substantially more abundant in smokers.
CONCLUSION
This study highlights the significant influence of smoking on the composition of the oral microbiome by enriching anaerobic microbes and depleting aerobic microbes. Moreover, the observed correlation between Streptococcus abundance and the lipid biomarkers suggests a potential link between smokers-induced salivary microbiome dysbiosis and lipid metabolism. Understanding the impact of smoking on altering the oral microbiome composition and its correlation with chemistry tests is essential for developing targeted interventions and strategies to improve oral health and reduce the risk of diseases.
Topics: Humans; Saliva; Dysbiosis; Smoking; Male; Microbiota; Female; Biomarkers; Adult; Lipids; Middle Aged; RNA, Ribosomal, 16S
PubMed: 38796419
DOI: 10.1186/s12903-024-04340-4 -
International Journal of Molecular... May 2024The most common type of periodontal disease is chronic periodontitis, an inflammatory condition caused by pathogenic bacteria in subgingival plaque. The aim of our study...
The most common type of periodontal disease is chronic periodontitis, an inflammatory condition caused by pathogenic bacteria in subgingival plaque. The aim of our study was the development of a real-time PCR test as a diagnostic tool for the detection and differentiation of five periodontopathogenic bacteria, , , , , and , in patients with periodontitis. We compared the results of our in-house method with the micro-IDent semiquantitative commercially available test based on the PCR hybridization method. DNA was isolated from subgingival plaque samples taken from 50 patients and then analyzed by both methods. Comparing the results of the two methods, they show a specificity of 100% for all bacteria. The sensitivity for was 97.5%, for 96.88%, and for 95.24%. The sensitivity for and was 100%. The Spearman correlation factor of two different measurements was 0.976 for , 0.967 for , 0.949 for , 0.966 for , and 0.917 for . In conclusion, the in-house real-time PCR method developed in our laboratory can provide information about relative amount of five bacterial species present in subgingival plaque in patients with periodontitis. It is likely that such a test could be used in dental diagnostics in assessing the efficacy of any treatment to reduce the bacterial burden.
Topics: Humans; Real-Time Polymerase Chain Reaction; Periodontitis; Porphyromonas gingivalis; Aggregatibacter actinomycetemcomitans; Treponema denticola; Male; Female; Tannerella forsythia; Sensitivity and Specificity; Prevotella intermedia; Middle Aged; Adult; DNA, Bacterial; Dental Plaque; Bacteria
PubMed: 38791137
DOI: 10.3390/ijms25105097 -
International Journal of Molecular... May 2024Periodontitis is linked to the onset and progression of oral squamous cell carcinoma (OSCC), an epidemiologically frequent and clinically aggressive malignancy. In this... (Review)
Review
Periodontitis is linked to the onset and progression of oral squamous cell carcinoma (OSCC), an epidemiologically frequent and clinically aggressive malignancy. In this context, and , two bacteria that cause periodontitis, are found in OSCC tissues as well as in oral premalignant lesions, where they exert pro-tumorigenic activities. Since the two bacteria are present also in endodontic diseases, playing a role in their pathogenesis, here we analyze the literature searching for information on the impact that endodontic infection by or could have on cellular and molecular events involved in oral carcinogenesis. Results from the reviewed papers indicate that infection by and/or triggers the production of inflammatory cytokines and growth factors in dental pulp cells or periodontal cells, affecting the survival, proliferation, invasion, and differentiation of OSCC cells. In addition, the two bacteria and the cytokines they induce halt the differentiation and stimulate the proliferation and invasion of stem cells populating the dental pulp or the periodontium. Although most of the literature confutes the possibility that bacteria-induced endodontic inflammatory diseases could impact on oral carcinogenesis, the papers we have analyzed and discussed herein recommend further investigations on this topic.
Topics: Humans; Porphyromonas gingivalis; Fusobacterium nucleatum; Mouth Neoplasms; Fusobacterium Infections; Carcinogenesis; Bacteroidaceae Infections; Carcinoma, Squamous Cell; Periodontitis; Animals; Cytokines
PubMed: 38791123
DOI: 10.3390/ijms25105083 -
Biomedicines Apr 2024Patients with rheumatoid arthritis (RA) have altered levels of exhaled nitric oxide (NO) compared with healthy controls. Here, we investigated whether the clinical...
Patients with rheumatoid arthritis (RA) have altered levels of exhaled nitric oxide (NO) compared with healthy controls. Here, we investigated whether the clinical features of and immunological factors in RA pathogenesis could be linked to the NO lung dynamics in early disease. A total of 44 patients with early RA and anti-citrullinated peptide antibodies (ACPAs), specified as cyclic citrullinated peptide 2 (CCP2), were included. Their exhaled NO levels were measured, and the alveolar concentration, the airway compartment diffusing capacity and the airway wall concentration of NO were estimated using the Högman-Meriläinen algorithm. The disease activity was measured using the Disease Activity Score for 28 joints. Serum samples were analysed for anti-CCP2, rheumatoid factor, free secretory component, secretory component containing ACPAs, antibodies against (Rgp) and total levels of IgA, IgA1 and IgA2. Significant negative correlations were found between the airway wall concentration of NO and the number of swollen joints (Rho -0.48, = 0.004), between the airway wall concentration of NO and IgA rheumatoid factor (Rho -0.41, = 0.017), between the alveolar concentration and free secretory component (Rho -0.35, = 0.023) and between the alveolar concentration and C-reactive protein (Rho -0.36, = 0.016), but none were found for anti-CCP2, IgM rheumatoid factor or the anti-Rgp levels. In conclusion, altered NO levels, particularly its production in the airway walls, may have a role in the pathogenesis of ACPA-positive RA.
PubMed: 38790926
DOI: 10.3390/biomedicines12050964 -
Antioxidants (Basel, Switzerland) Apr 2024Hinokitiol (HKT) is one of the essential oil components found in the heartwood of Cupressaceae plants, and has been reported to have various bioactive effects, including...
Hinokitiol (HKT) is one of the essential oil components found in the heartwood of Cupressaceae plants, and has been reported to have various bioactive effects, including anti-inflammatory effects. However, the improving effect of HKT on periodontitis, which is characterized by periodontal tissue inflammation and alveolar bone loss, has not been clearly revealed. Therefore, we investigated the periodontitis-alleviating effect of HKT and the related molecular mechanisms in human periodontal ligament cells. According to the study results, HKT downregulated SIRT1 and NOX4, which were increased by Lipopolysaccharide (PG-LPS) stimulation and were found to regulate pro-inflammatory mediators and oxidative stress through SIRT1/NOX4 signals. Additionally, by increasing the expression of osteogenic makers such as alkaline phosphatase, osteogenic induction of human periodontal ligament (HPDL) cells, which had been reduced by PG-LPS, was restored. Furthermore, we confirmed that NOX4 expression was regulated through regulation of SIRT1 expression with HKT. The in vitro effect of HKT on improving periodontitis was proven using the periodontal inflammation model, which induces periodontal inflammation using ligature, a representative in vivo model. According to in vivo results, HKT alleviated periodontal inflammation and restored damaged alveolar bone in a concentration-dependent manner in the periodontal inflammation model. Through this experiment, the positive effects of HKT on relieving periodontal tissue inflammation and recovering damaged alveolar bone, which are important treatment strategies for periodontitis, were confirmed. Therefore, these results suggest that HKT has potential in the treatment of periodontitis.
PubMed: 38790655
DOI: 10.3390/antiox13050550