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International Journal of Molecular... Apr 2024(Pg) and its gingipain proteases contribute to Alzheimer's disease (AD) pathogenesis through yet unclear mechanisms. Cellular secretion of small extracellular vesicles...
(Pg) and its gingipain proteases contribute to Alzheimer's disease (AD) pathogenesis through yet unclear mechanisms. Cellular secretion of small extracellular vesicles or exosomes (EXO) increases with aging as part of the senescence-associated secretory phenotype (SASP). We have shown that EXO isolated from Pg-infected dendritic cells contain gingipains and other Pg antigens and transmit senescence to bystander gingival cells, inducing alveolar bone loss in mice in vivo. Here, EXO were isolated from the gingiva of mice and humans with/without periodontitis (PD) to determine their ability to penetrate the blood-brain barrier (BBB) in vitro and in vivo. PD was induced by Pg oral gavage for 6 weeks in C57B6 mice. EXO isolated from the gingiva or brain of donor Pg-infected (PD EXO) or control animals (Con EXO) were characterized by NTA, Western blot, and TEM. Gingival PD EXO or Con EXO were labeled and injected into the gingiva of uninfected WT mouse model. EXO biodistribution in brains was tracked by an in vivo imaging system (IVIS) and confocal microscopy. The effect of human PD EXO on BBB integrity and permeability was examined using TEER and FITC dextran assays in a human in vitro 3D model of the BBB. Pg antigens (RGP and Mfa-1) were detected in EXO derived from gingival and brain tissues of donor Pg-infected mice. Orally injected PD EXO from donor mice penetrated the brains of recipient uninfected mice and colocalized with hippocampal microglial cells. IL-1β and IL-6 were expressed in human PD EXO and not in Con EXO. Human PD EXO promoted BBB permeability and penetrated the BBB in vitro. This is the first demonstration that microbial-induced EXO in the oral cavity can disseminate, cross the BBB, and may contribute to AD pathogenesis.
Topics: Blood-Brain Barrier; Animals; Humans; Mice; Extracellular Vesicles; Porphyromonas gingivalis; Periodontitis; Gingiva; Mice, Inbred C57BL; Male; Exosomes; Female; Bacteroidaceae Infections
PubMed: 38674094
DOI: 10.3390/ijms25084509 -
Microbiome Jul 2023Porphyromonas gingivalis (hereafter "Pg") is an oral pathogen that has been hypothesized to act as a keystone driver of inflammation and periodontal disease. Although Pg...
BACKGROUND
Porphyromonas gingivalis (hereafter "Pg") is an oral pathogen that has been hypothesized to act as a keystone driver of inflammation and periodontal disease. Although Pg is most readily recovered from individuals with actively progressing periodontal disease, healthy individuals and those with stable non-progressing disease are also colonized by Pg. Insights into the factors shaping the striking strain-level variation in Pg, and its variable associations with disease, are needed to achieve a more mechanistic understanding of periodontal disease and its progression. One of the key forces often shaping strain-level diversity in microbial communities is infection of bacteria by their viral (phage) predators and symbionts. Surprisingly, although Pg has been the subject of study for over 40 years, essentially nothing is known of its phages, and the prevailing paradigm is that phages are not important in the ecology of Pg.
RESULTS
Here we systematically addressed the question of whether Pg are infected by phages-and we found that they are. We found that prophages are common in Pg, they are genomically diverse, and they encode genes that have the potential to alter Pg physiology and interactions. We found that phages represent unrecognized targets of the prevalent CRISPR-Cas defense systems in Pg, and that Pg strains encode numerous additional mechanistically diverse candidate anti-phage defense systems. We also found that phages and candidate anti-phage defense system elements together are major contributors to strain-level diversity and the species pangenome of this oral pathogen. Finally, we demonstrate that prophages harbored by a model Pg strain are active in culture, producing extracellular viral particles in broth cultures.
CONCLUSION
This work definitively establishes that phages are a major unrecognized force shaping the ecology and intra-species strain-level diversity of the well-studied oral pathogen Pg. The foundational phage sequence datasets and model systems that we establish here add to the rich context of all that is already known about Pg, and point to numerous avenues of future inquiry that promise to shed new light on fundamental features of phage impacts on human health and disease broadly. Video Abstract.
Topics: Humans; Bacteriophages; Porphyromonas gingivalis; Prophages; Periodontal Diseases; Base Sequence
PubMed: 37491415
DOI: 10.1186/s40168-023-01607-w -
Scientific Reports Mar 2024Porphyromonas gingivalis, a Gram-negative anaerobic bacterium commonly found in human subgingival plaque, is a major etiologic agent for periodontitis and has been...
Porphyromonas gingivalis, a Gram-negative anaerobic bacterium commonly found in human subgingival plaque, is a major etiologic agent for periodontitis and has been associated with multiple systemic pathologies. Many P. gingivalis strains have been identified and different strains possess different virulence factors. Current oral microbiome approaches (16S or shotgun) have been unable to differentiate P. gingivalis strains. This study presents a new approach that aims to improve the accuracy of strain identification, using a detection method based on sequencing of the intergenic spacer region (ISR) which is variable between P. gingivalis strains. Our approach uses two-step PCR to amplify only the P. gingivalis ISR region. Samples are then sequenced with an Illumina sequencer and mapped to specific strains. Our approach was validated by examining subgingival plaque from 153 participants with and without periodontal disease. We identified the avirulent strain ATCC33277/381 as the most abundant strain across all sample types. The W83/W50 strain was significantly enriched in periodontitis, with 13% of participants harboring that strain. Overall, this approach can have significant implications not only for the diagnosis and treatment of periodontal disease but also for other diseases where P. gingivalis or its toxins have been implicated, such as Alzheimer's disease.
Topics: Humans; Porphyromonas gingivalis; Base Composition; Sequence Analysis, DNA; RNA, Ribosomal, 16S; Phylogeny; Periodontitis
PubMed: 38485747
DOI: 10.1038/s41598-024-56849-x -
International Journal of Molecular... Apr 2024The aim of this comprehensive review is to summarize recent literature on associations between periodontitis and neurodegenerative diseases, explore the bidirectionality... (Review)
Review
The aim of this comprehensive review is to summarize recent literature on associations between periodontitis and neurodegenerative diseases, explore the bidirectionality and provide insights into the plausible pathogenesis. For this purpose, systematic reviews and meta-analyses from PubMed, Medline and EMBASE were considered. Out of 33 retrieved papers, 6 articles complying with the inclusion criteria were selected and discussed. Additional relevant papers for bidirectionality and pathogenesis were included. Results show an association between periodontitis and Alzheimer's disease, with odds ratios of 3 to 5. A bidirectional relationship is suspected. For Parkinson's disease (PD), current evidence for an association appears to be weak, although poor oral health and PD seem to be correlated. A huge knowledge gap was identified. The plausible mechanistic link for the association between periodontitis and neurodegenerative diseases is the interplay between periodontal inflammation and neuroinflammation. Three pathways are hypothesized in the literature, i.e., humoral, neuronal and cellular, with a clear role of periodontal pathogens, such as . Age, gender, race, smoking, alcohol intake, nutrition, physical activity, socioeconomic status, stress, medical comorbidities and genetics were identified as common risk factors for periodontitis and neurodegenerative diseases. Future research with main emphasis on the collaboration between neurologists and dentists is encouraged.
Topics: Humans; Periodontitis; Risk Factors; Neurodegenerative Diseases; Parkinson Disease; Alzheimer Disease
PubMed: 38674088
DOI: 10.3390/ijms25084504 -
Journal of Advanced Research Jan 2024Chronic apical periodontitis (CAP) is a common infectious disease of the oral cavity. Immune responses and osteoclastogenesis of monocytes/macrophages play a crucial...
INTRODUCTION
Chronic apical periodontitis (CAP) is a common infectious disease of the oral cavity. Immune responses and osteoclastogenesis of monocytes/macrophages play a crucial role in CAP progression, and this study want to clarify role of monocytes/macrophages in CAP, which will contribute to treatment of CAP.
OBJECTIVES
We aim to explore the heterogeneity of monocyte populations in periapical lesion of CAP tissues and healthy control (HC) periodontal tissues by single-cell RNA sequencing (scRNA-seq), search novel targets for alleviating CAP, and further validate it by proteomics and in vitro and in vivo evaluations.
METHODS
ScRNA-seq was used to analyze the heterogeneity of monocyte populations in CAP, and proteomics of THP-1-derived macrophages with porphyromonas gingivalis infection were intersected with the differentially expressed genes (DEGs) of macrophages between CAP and HC tissues. The upregulated PTMA (prothymosin-α) were validated by immunofluorescence staining and quantitative real time polymerase chain reaction. We evaluated the effect of thymosin α1 (an amino-terminal proteolytic cleavage product of PTMA protein) on inflammatory factors and osteoclast differentiation of macrophages infected by P. gingivalis. Furthermore, we constructed mouse and rat mandibular bone lesions caused by apical periodontitis, and estimated treatment of systemic and topical administration of PTMA for CAP. Statistical analyses were performed using GraphPad Prism software (v9.2) RESULTS: Monocytes were divided into seven sub-clusters comprising monocyte-macrophage-osteoclast (MMO) differentiation in CAP. 14 up-regulated and 21 down-regulated genes and proteins were intersected between the DEGs of scRNA-seq data and proteomics, including the high expression of PTMA. Thymosin α1 may decrease several inflammatory cytokine expressions and osteoclastogenesis of THP-1-derived macrophages. Both systemic administration in mice and topical administration in the pulp chamber of rats alleviated periapical lesions.
CONCLUSIONS
PTMA upregulation in CAP moderates the inflammatory response and prevents the osteoclastogenesis of macrophages, which provides a basis for targeted therapeutic strategies for CAP.
PubMed: 38237771
DOI: 10.1016/j.jare.2024.01.018 -
Cell Communication and Signaling : CCS Jan 2024Cementoblasts on the tooth-root surface are responsible for cementum formation (cementogenesis) and sensitive to Porphyromonas gingivalis stimulation. We have previously...
BACKGROUND
Cementoblasts on the tooth-root surface are responsible for cementum formation (cementogenesis) and sensitive to Porphyromonas gingivalis stimulation. We have previously proved transcription factor CXXC-type zinc finger protein 5 (CXXC5) participates in cementogenesis. Here, we aimed to elucidate the mechanism in which CXXC5 regulates P. gingivalis-inhibited cementogenesis from the perspective of mitochondrial biogenesis.
METHODS
In vivo, periapical lesions were induced in mouse mandibular first molars by pulp exposure, and P. gingivalis was applied into the root canals. In vitro, a cementoblast cell line (OCCM-30) was induced cementogenesis and submitted for RNA sequencing. These cells were co-cultured with P. gingivalis and examined for osteogenic ability and mitochondrial biogenesis. Cells with stable CXXC5 overexpression were constructed by lentivirus transduction, and PGC-1α (central inducer of mitochondrial biogenesis) was down-regulated by siRNA transfection.
RESULTS
Periapical lesions were enlarged, and PGC-1α expression was reduced by P. gingivalis treatment. Upon apical inflammation, Cxxc5 expression decreased with Il-6 upregulation. RNA sequencing showed enhanced expression of osteogenic markers, Cxxc5, and mitochondrial biogenesis markers during cementogenesis. P. gingivalis suppressed osteogenic capacities, mitochondrial biogenesis markers, mitochondrial (mt)DNA copy number, and cellular ATP content of cementoblasts, whereas CXXC5 overexpression rescued these effects. PGC-1α knockdown dramatically impaired cementoblast differentiation, confirming the role of mitochondrial biogenesis on cementogenesis.
CONCLUSIONS
CXXC5 is a P. gingivalis-sensitive transcription factor that positively regulates cementogenesis by influencing PGC-1α-dependent mitochondrial biogenesis. Video Abstract.
Topics: Animals; Mice; Cell Line; Cementogenesis; DNA, Mitochondrial; DNA-Binding Proteins; Gene Expression Regulation; Organelle Biogenesis; Transcription Factors; Mitochondria
PubMed: 38167023
DOI: 10.1186/s12964-023-01283-1 -
Frontiers in Endocrinology 2023The objective was to investigate the association of periodontitis and tooth loss with extent of diabetic coronary atherosclerosis.
AIM
The objective was to investigate the association of periodontitis and tooth loss with extent of diabetic coronary atherosclerosis.
MATERIALS AND METHODS
272 patients who were hospitalized at Shanghai East hospital and underwent a coronary artery calcium (CAC) CT scan were enrolled in this study. Individuals were grouped based on their CAC scores into a normal-to-mild coronary atherosclerosis (AS) group (0 ≤ score ≤ 100, n=184) and a moderate-to-severe group (score≥101, n=88). Periodontitis parameters and number of missing teeth were evaluated for every patient. The severity of periodontitis was categorized as mild, moderate, or severe. The taxonomic composition of the microbiota was determined using full-length 16S ribosomal RNA gene sequencing. Salivary inflammatory factors were tested by ELISA.
RESULTS
Clinical attachment loss (CAL) (P =0.05) and the number of teeth lost (P = 0.016) were significantly higher in the moderate-to-severe coronary AS group, with these differences being more obvious in younger patients and patients with short-duration diabetes. Multivariate logistic regression analysis revealed that CAL (OR = 1.231, 95% CI = 1.066-1.214, P = 0.047) and having 10-19 missing teeth (OR = 1.604, 95% CI = 1.393-6.555, P = 0.05) were strongly associated with the presence of moderate-to-severe coronary AS. Salivary IL-6 and TNF-α levels, as well as levels of Porphyromonas gingivalis and Neisseria mucosa, were significantly elevated in the moderate-to-severe coronary AS group.
CONCLUSION
It was found that both tooth loss and CAL were related to the extent of diabetic coronary AS. Saliva inflammatory factors and oral bacteremia may be new biomarkers for moderate-to-severe coronary AS.
Topics: Humans; Coronary Artery Disease; Diabetes Mellitus, Type 2; Tooth Loss; China; Periodontitis
PubMed: 38075042
DOI: 10.3389/fendo.2023.1243992 -
Molecules (Basel, Switzerland) Dec 2023Periodontal disease is a chronic disease with a high prevalence, and in order to secure natural materials to prevent oral diseases, new materials that protect...
Periodontal disease is a chronic disease with a high prevalence, and in order to secure natural materials to prevent oral diseases, new materials that protect periodontal tissue from inflammation are being sought. Genes were identified using real-time quantitative polymerase chain reaction (RT-qPCR), and proteins were confirmed using Western blot. Dichlorodihydrofluorescein diacetate (DCF-DA) analysis was used, and the antibacterial effects were confirmed through Minimum Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) analysis. To confirm this effect in vivo, Sprague-Dawley rats, in which periodontitis was induced using ligation or Lipopolysaccharide of (PG-LPS), were used. In vitro experiments using human periodontal ligament (HPDL) cells stimulated with PG-LPS showed that Ginsenoside Rg6 (G-Rg6) had anti-inflammatory, antibacterial, antioxidant, and osteoblast differentiation properties. In vivo, G-Rg6 was effective in Sprague-Dawley rats in which periodontitis was induced using ligation or PG-LPS. Therefore, Ginsenoside Rg6 shows potential effectiveness in alleviating periodontitis.
Topics: Rats; Humans; Animals; Lipopolysaccharides; Rats, Sprague-Dawley; Inflammation; Anti-Bacterial Agents; Porphyromonas gingivalis; Periodontitis; Ginsenosides
PubMed: 38202632
DOI: 10.3390/molecules29010046 -
Clinical Oral Investigations Oct 2023The present study aimed to evaluate the potential of the salivary pellicle (SP) formed on titanium (Ti) surfaces to modulate the formation of a biofilm composed of...
OBJECTIVES
The present study aimed to evaluate the potential of the salivary pellicle (SP) formed on titanium (Ti) surfaces to modulate the formation of a biofilm composed of Streptococcus gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis.
MATERIALS AND METHODS
Ti substrates were incubated for 2 h with a pool of saliva samples obtained from 10 systemically and periodontally healthy subjects. Enamel substrates were included as a biological reference. Scanning electron microscopy (SEM) and Raman spectroscopy analysis were used to analyze the formation of the salivary pellicle. After the SP formation, the surfaces were incubated for 12 h with a mix of Streptococcus gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis. The number of bacterial cells attached to each surface was determined by the XTT assay while bacterial viability was analyzed by fluorescence microscopy using the LIVE/DEAD® BacLight kit.
RESULTS
The SEM and Raman spectroscopy analysis confirmed the presence of a salivary pellicle formed on the tested surfaces. Regarding the biofilm formation, the presence of the SP decreases the number of the bacterial cells detected in the test surfaces, compared with the uncover substrates. Even more, the SP-covered substrates showed similar bacterial counts in both Ti and enamel surfaces, meaning that the physicochemical differences of the substrates were less determinant than the presence of the SP. While on the SP-uncover substrates, differences in the bacterial adhesion patterns were directly related to the physicochemical nature of the substrates.
CONCLUSIONS
The salivary pellicle was the main modulator in the development of the biofilm consisting of representative oral bacteria on the Ti substrates.
CLINICAL RELEVANCE
The results of this study provide valuable information on the modulatory effect of the salivary pellicle on biofilm formation; such information allows us to understand better the events involved in the formation of oral biofilms on Ti dental implants.
Topics: Humans; Dental Pellicle; Titanium; Biofilms; Bacterial Adhesion; Streptococcus gordonii; Fusobacterium nucleatum; Surface Properties
PubMed: 37646908
DOI: 10.1007/s00784-023-05230-9 -
MSystems Oct 2023The characteristics of blood microbiota in HIV-infected individuals and their relevance to disease progression are still unknown, despite alterations in gut microbiota...
The characteristics of blood microbiota in HIV-infected individuals and their relevance to disease progression are still unknown, despite alterations in gut microbiota diversity and composition in HIV-infected individuals. Here, we present evidence of increased blood microbiota diversity in HIV-infected individuals, which may result from gut microbiota translocation. Also, we identify a group of microbes, , sp. , sp. , , , sp. , and , which are linked to poor immunological recovery. This work provides a scientific foundation toward therapeutic strategies targeting blood microbiota for immune recovery of HIV infection.
Topics: Humans; Acquired Immunodeficiency Syndrome; HIV Infections; Immune Reconstitution; Microbiota; Inflammation; Prevotella
PubMed: 37698407
DOI: 10.1128/msystems.00467-23