Two Small Molecules Block Oral Epithelial Cell Invasion by Porphyromons gingivalis.
Ontology highlight
ABSTRACT:
SUBMITTER: Ho MH
PROVIDER: S-EPMC4760928 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Peptidylarginine deiminase (PPAD) is a virulence factor unique to pathogenic Porphyromonas species, especially P. gingivalis. Mechanistically, PPAD activity, in conjunction with Arg-specific gingipains, generates protein fragments with citrullinated C-termini. Such polypeptides are potential de novo epitopes that are key drivers of rheumatoid arthritis. This process could underlie the observed clinical association between rheumatoid arthritis and periodontitis. However, the role of PPAD in host colonization by P. gingivalis and, subsequently, in triggering periodontitis is not known. Therefore, the aim of the current study was to delineate the role of PPAD in bacterial biofilm formation, and to define whether adherence to, invasion of, and host responses to bacteria of gingival keratinocytes depend on PPAD activity. We studied these aspects using PPAD-competent and PPAD-incompetent strains of P. gingivalis, and demonstrated that neither biofilm formation nor its composition was affected by PPAD activity. Similarly, flow cytometry revealed that PPAD did not impact the ability of P. gingivalis to adhere to and, subsequently, invade keratinocytes. Network analyses of gene expression patterns, however, revealed a group of host genes that were sensitive to PPAD activity (CXCL8, IL36G, CCL20, and IL1B). These genes can be categorized as potent immune modulators belonging to the interleukin 1 system, or chemoattractants of lymphocytes and neutrophils. Thus, we conclude that PPAD, although it is a potent modulator of the immune response, does not affect bacterial biofilm formation or the ability of P. gingivalis to adhere to and invade gingival epithelial cells.
| S-EPMC6147916 | biostudies-literature
Project description:Emerging antibiotic resistance demands identification of novel antibacterial compound classes. A bacterial whole-cell screen based on pneumococcal autolysin-mediated lysis induction was developed to identify potential bacterial cell wall synthesis inhibitors. A hit class comprising a 1-amino substituted tetrahydrocarbazole (THCz) scaffold, containing two essential amine groups, displayed bactericidal activity against a broad range of gram-positive and selected gram-negative pathogens in the low micromolar range. Mode of action studies revealed that THCz inhibit cell envelope synthesis by targeting undecaprenyl pyrophosphate-containing lipid intermediates and thus simultaneously inhibit peptidoglycan, teichoic acid, and polysaccharide capsule biosynthesis. Resistance did not readily develop in vitro, and the ease of synthesizing and modifying these small molecules, as compared to natural lipid II-binding antibiotics, makes THCz promising scaffolds for development of cell wall-targeting antimicrobials.
| S-EPMC8617507 | biostudies-literature
Project description:Recent epidemiological studies have revealed a significant association between periodontitis and oral squamous cell carcinoma (OSCC). Furthermore, matrix metalloproteinase 9 (MMP9) is implicated in the invasion and metastasis of tumour cells. We examined the involvement of Porphyromonas gingivalis, a periodontal pathogen, in OSCC invasion through induced expression of proMMP and its activation. proMMP9 was continuously secreted from carcinoma SAS cells, while P.?gingivalis infection increased proenzyme expression and subsequently processed it to active MMP9 in culture supernatant, which enhanced cellular invasion. In contrast, Fusobacterium nucleatum, another periodontal organism, failed to demonstrate such activities. The effects of P.?gingivalis were observed with highly invasive cells, but not with the low invasivetype. P.?gingivalis also stimulated proteinase-activated receptor 2 (PAR2) and enhanced proMMP9 expression, which promoted cellular invasion. P.?gingivalis mutants deficient in gingipain proteases failed to activate MMP9. Infected SAS cells exhibited activation of ERK1/2, p38, and NF-kB, and their inhibitors diminished both proMMP9-overexpression and cellular invasion. Together, our results show that P.?gingivalis activates the ERK1/2-Ets1, p38/HSP27, and PAR2/NF-kB pathways to induce proMMP9 expression, after which the proenzyme is activated by gingipains to promote cellular invasion of OSCC cell lines. These findings suggest a novel mechanism of progression and metastasis of OSCC associated with periodontitis.
| S-EPMC3939075 | biostudies-literature
Project description:BackgroundPorphyromonas gingivalis (P. gingivalis) and Fusobacterium nucleatum (F. nucleatum) participate in the formation and progression of periodontitis. They can exert virulence by invading into host cells, but the interaction between them and their specific mechanisms remain unclear. The purpose of this study was to study the effect of P. gingivalis outer membrane vesicles (OMVs) on the ability of F. nucleatum to invade oral epithelial cells, and the reasons for the influence.MethodsThe invasion abilities of the two bacteria were detected separately after mixed infection of P. gingivalis and F. nucleatum. Next, P. gingivalis OMVs were extracted with the kit, and their influence on the invasion ability of F. nucleatum was tested. The effects of P. gingivalis OMVs on F. nucleatum were evaluated by assessment of bacterial morphology, growth curves, auto-aggregation morphology, and the expression of adhesion-related proteins FadA and FomA.ResultsOur results showed that P. gingivalis inhibited the invasion of F. nucleatum into oral epithelial cells but F. nucleatum promoted the invasion of P. gingivalis. In subsequent experiments, we extracted P. gingivalis OMVs successfully and revealed that proteases in P. gingivalis OMVs inhibited the invasion of F. nucleatum into oral epithelial cells. Furthermore, P. gingivalis OMVs did not affect the morphology and proliferation of F. nucleatum, but proteases inside decreased the auto-aggregation of F. nucleatum. Additionally, proteases in P. gingivalis OMVs reduced the expression levels of F. nucleatum surface adhesion-related proteins FadA and FomA.ConclusionOur study demonstrated that proteases in P. gingivalis OMVs inhibited the invasion of F. nucleatum into oral epithelial cells by downregulating FadA and FomA.
| S-EPMC9415117 | biostudies-literature
Project description:Recent epidemiological studies revealed a significant association between oral squamous cell carcinoma (OSCC) and Porphyromonas gingivalis, a major pathogen of periodontal disease. As a keystone pathogen of periodontitis, P. gingivalis is known not only to damage local periodontal tissues, but also to evade the host immune system and eventually affect systemic health. However, its role in OSCC has yet to be defined. To explore the underlying effect of chronic P. gingivalis infection on OSCC and to identify relevant biomarkers as promising targets for therapy and prevention, we established a novel model by exposing human immortalized oral epithelial cells (HIOECs) to P. gingivalis at a low multiplicity of infection (MOI) for 5-23 weeks. The P. gingivalis infected HIOECs were monitored for tumor biological alteration by proliferation, wound healing, transwell invasion, and gelatin zymography assays. Microarray and proteomic analyses were performed on HIOECs infected with P. gingivalis for 15 weeks, and some selected data were validated by quantitative real-time PCR and (or) western blot on cells infected for 15 and 23 weeks. Persistent exposure to P. gingivalis caused cell morphological changes, increased proliferation ability with higher S phase fraction in the cell cycle, and promoted cell migratory and invasive properties. In combining results of bioinformatics analyses and validation assays, tumor-related genes such as NNMT, FLI1, GAS6, lncRNA CCAT1, PDCD1LG2, and CD274 may be considered as the key regulators in tumor-like transformation in response to long-time exposure of P. gingivalis. In addition, some useful clinical biomarkers and novel proteins were also presented. In conclusion, P. gingivalis could promote tumorigenic properties of HIOECs, indicating that chronic P. gingivalis infection may be considered as a potential risk factor for oral cancer. The key regulators detected from the present model might be used in monitoring the development of OSCC with chronic periodontal infection.
| S-EPMC5323389 | biostudies-literature
Project description:Oral mucosa provides the first line of defense against a diverse array of environmental and microbial irritants by forming the barrier of epithelial cells interconnected by multiprotein tight junctions (TJ), adherens junctions, desmosomes, and gap junction complexes. Grainyhead-like 2 (GRHL2), an epithelial-specific transcription factor, may play a role in the formation of the mucosal epithelial barrier, as it regulates the expression of the junction proteins. The current study investigated the role of GRHL2 in the Porphyromonas gingivalis (Pg)-induced impairment of epithelial barrier functions. Exposure of human oral keratinocytes (HOK-16B and OKF6 cells) to Pg or Pg-derived lipopolysaccharides (Pg LPSs) led to rapid loss of endogenous GRHL2 and the junction proteins (e.g., zonula occludens, E-cadherin, claudins, and occludin). GRHL2 directly regulated the expression levels of the junction proteins and the epithelial permeability for small molecules (e.g., dextrans and Pg bacteria). To explore the functional role of GRHL2 in oral mucosal barrier, we used a Grhl2 conditional knockout (KO) mouse model, which allows for epithelial tissue-specific Grhl2 KO in an inducible manner. Grhl2 KO impaired the expression of the junction proteins at the junctional epithelium and increased the alveolar bone loss in the ligature-induced periodontitis model. Fluorescence in situ hybridization revealed increased epithelial penetration of oral bacteria in Grhl2 KO mice compared with the wild-type mice. Also, blood loadings of oral bacteria (e.g., Bacteroides, Bacillus, Firmicutes, β-proteobacteria, and Spirochetes) were significantly elevated in Grhl2 KO mice compared to the wild-type littermates. These data indicate that Pg bacteria may enhance paracellular penetration through oral mucosa in part by targeting the expression of GRHL2 in the oral epithelial cells, which then impairs the epithelial barrier by inhibition of junction protein expression, resulting in increased alveolar tissue destruction and systemic bacteremia.
| S-EPMC6704429 | biostudies-literature
Project description:Bistable populations of bacteria give rise to two or more subtypes that exhibit different phenotypes. We have explored whether the periodontal pathogen, Porphyromonas gingivalis, exhibits bistable invasive phenotypes. Using a modified cell invasion assay, we show for the first time that there are two distinct sub-types within a population of P.ginigivalis strains NCTC 11834 and W50 that display differences in their ability to invade oral epithelial cells. The highly-invasive sub-types invade cells at 10-30 fold higher levels than the poorly-invasive subtype and remain highly invasive for approximately 12-16 generations. Analysis of the gingipain activity of these sub-types revealed that the highly invasive type had reduced cell-associated arginine specific protease activity. The role of arg-gingipain activity in invasion was verified by enhancement of invasion by rgpAB mutations and by inclusion of an arg-gingipain inhibitor in invasion assays using wild-type bacteria. In addition a population of DeltargpAB bacteria did not contain a hyperinvasive sub-type. Screening of the protease activity of wild-type populations of both strains identified high and low protease sub-types which also showed the corresponding reduction or enhancement of invasive capabilities. Microarray analysis of these bistable populations revealed a putative signature set of genes that include oxidative stress resistance and iron transport genes that might be key to invasion of or survival within epithelial cells. Porphyromonas gingivalis comparison of Invasive V Non-invasive sub-types of NCTC11834 and W50 (samples 1-12 AND High V low protease subtypes (samples 13-24) Samples 1-3 were compared top 4-6 and 7-9 V 10-12 for invasive experiments and similarly for protease strain experiments
2010-08-31 | E-GEOD-23021 | biostudies-arrayexpress
Project description:Bistable populations of bacteria give rise to two or more subtypes that exhibit different phenotypes. We have explored whether the periodontal pathogen, Porphyromonas gingivalis, exhibits bistable invasive phenotypes. Using a modified cell invasion assay, we show for the first time that there are two distinct sub-types within a population of P.ginigivalis strains NCTC 11834 and W50 that display differences in their ability to invade oral epithelial cells. The highly-invasive sub-types invade cells at 10-30 fold higher levels than the poorly-invasive subtype and remain highly invasive for approximately 12-16 generations. Analysis of the gingipain activity of these sub-types revealed that the highly invasive type had reduced cell-associated arginine specific protease activity. The role of arg-gingipain activity in invasion was verified by enhancement of invasion by rgpAB mutations and by inclusion of an arg-gingipain inhibitor in invasion assays using wild-type bacteria. In addition a population of DeltargpAB bacteria did not contain a hyperinvasive sub-type. Screening of the protease activity of wild-type populations of both strains identified high and low protease sub-types which also showed the corresponding reduction or enhancement of invasive capabilities. Microarray analysis of these bistable populations revealed a putative signature set of genes that include oxidative stress resistance and iron transport genes that might be key to invasion of or survival within epithelial cells.
2010-08-31 | GSE23021 | GEO
Project description:The human microbiome is a collection of microorganisms that inhabit every surface of the body that is exposed to the environment, generally coexisting peacefully with their host. These microbes have important functions, such as producing vitamins, aiding in maturation of the immune system, and protecting against pathogens. We have previously shown that a small-molecule extract from the human fecal microbiome has a strong repressive effect on Salmonella enterica serovar Typhimurium host cell invasion by modulating the expression of genes involved in this process. Here, we describe the characterization of this biological activity. Using a series of purification methods, we obtained fractions with biological activity and characterized them by mass spectrometry. These experiments revealed an abundance of aromatic compounds in the bioactive fraction. Selected compounds were obtained from commercial sources and tested with respect to their ability to repress the expression of hilA, the gene encoding the master regulator of invasion genes in Salmonella We found that the aromatic compound 3,4-dimethylbenzoic acid acts as a strong inhibitor of hilA expression and of invasion of cultured host cells by Salmonella Future studies should reveal the molecular details of this phenomenon, such as the signaling cascades involved in sensing this bioactive molecule.IMPORTANCE Microbes constantly sense and adapt to their environment. Often, this is achieved through the production and sensing of small extracellular molecules. The human body is colonized by complex communities of microbes, and, given their biological and chemical diversity, these ecosystems represent a platform where the production and sensing of molecules occur. In previous work, we showed that small molecules produced by microbes from the human gut can significantly impair the virulence of the enteric pathogen Salmonella enterica Here, we describe a specific compound from the human gut that produces this same effect. The results from this work not only shed light on an important biological phenomenon occurring in our bodies but also may represent an opportunity to develop drugs that can target these small-molecule interactions to protect us from enteric infections and other diseases.
| S-EPMC5601338 | biostudies-literature
Project description:HIV-1 relies on the host's cell machinery to establish a successful infection. Surface receptors, such as CD4, CCR5, and CXCR4 of T cells and macrophages, are essential for membrane fusion of HIV-1, an initiate step in viral entry. However, it is not well defined how HIV-1 infects CD4-negative mucosal epithelial cells. Here we show that there is a specific interaction between HIV-1 and an invasive oral bacterium, Porphyromonas gingivalis. We found that HIV-1 was trapped on the bacterial surface, which led to internalization of HIV-1 virions as the bacteria invaded CD4-negative epithelial cells. Both bacterial and viral DNA was detected in HeLa and TERT-2 cells exposed to the HIV-1-P. gingivalis complexes 2 hr after the initial infection but not in cells exposed to HIV-1 alone. Moreover, epithelial cell entry of HIV-1 was positively correlated with invasive activity of the P. gingivalis strains tested, even when the binding affinities of HIV-1 to these strains were similar. Finally, it was demonstrated that the viral DNA was integrated into the genome of the host epithelial cells. These results reveal a receptor-independent HIV-1 entry into epithelial cells, which may be relevant in HIV transmission in other mucosal epithelia where complex microbial communities can be found.
| S-EPMC4126220 | biostudies-literature