There is strong epidemiological association between periodontal disease and cardiovascular disease but underlying mechanisms remain ill-defined. Because the human periodontal disease pathogen, ...Porphyromonas gingivalis (Pg), interacts with innate immune receptors Toll-like Receptor (TLR) 2 and CD36/scavenger receptor-B2 (SR-B2), we studied how CD36/SR-B2 and TLR pathways promote Pg-mediated atherosclerosis. Western diet fed low density lipoprotein receptor knockout (Ldlr°) mice infected orally with Pg had a significant increase in lesion burden compared with uninfected controls.This increase was entirely CD36/SR-B2-dependent, as there was no significant change in lesion burden between infected and uninfected Cd36o/Ldlro mice corrected. Western diet feeding promoted enhanced CD36/SR-B2-dependent IL1β generation and foam cell formation as a result of Pg lipopolysaccharide (PgLPS) exposure. CD36/SR-B2 and TLR2 were necessary for inflammasome activation and optimal IL1ß generation, but also resulted in LPS induced lethality (pyroptosis). Modified forms of LDL inhibited Pg-mediated IL1ß generation in a CD36/SR-B2-dependent manner and prevented pyroptosis, but promoted foam cell formation. Our data show that Pg infection in the oral cavity can lead to significant TLR2-CD36/SR-B2 dependent IL1ß release. In the vessel wall, macrophages encountering systemic release of IL1ß, PgLPS and modified LDL have increased lipid uptake, foam cell formation, and release of IL1ß, but because pyroptosis is inhibited, this enables macrophage survival and promotes increased plaque development. These studies may explain increased lesion burden as a result of periodontal disease, and suggest strategies for development of therapeutics.
The present study focused on exploring the associations of
(
) infection and low Beclin1 expression with clinicopathological parameters and survival of esophageal squamous cell carcinoma (ESCC) ...patients, so as to illustrate its clinical significance and prognostic value.
Immunohistochemistry (IHC) was used to detect
infection status and Beclin1 expression in 370 ESCC patients. The chi-square test was adopted to illustrate the relationship between categorical variables, and Cohen's kappa coefficient was used for correlation analysis. Kaplan-Meier survival curves with the log-rank test were used to analyse the correlation of
infection and low Beclin1 expression with survival time. The effects of
infection and Beclin1 downregulation on the proliferation, migration and antiapoptotic abilities of ESCC cells
were detected by Cell Counting Kit-8, wound healing and flow cytometry assays. For
infection of ESCC cells, cell culture medium was replaced with antibiotic-free medium when the density of ESCC cells was 70-80%, cells were inoculated with
at a multiplicity of infection (MOI) of 10.
infection was negatively correlated with Beclin1 expression in ESCC tissues, and
infection and low Beclin1 expression were associated with differentiation status, tumor invasion depth, lymph node metastasis, clinical stage and prognosis in ESCC patients.
experiments confirmed that
infection and Beclin1 downregulation potentiate the proliferation, migration and antiapoptotic abilities of ESCC cells (KYSE150 and KYSE30). Our results provide evidence that
infection and low Beclin1 expression were associated with the development and progression of ESCC.
Long-term smoking and alcohol consumption causes poor oral and esophageal microenvironments and ESCC patients with these features were more susceptible to
infection and persistent colonization, and exhibited lower Beclin1 expression, worse prognosis and more advanced clinicopathological features. Our findings indicate that effectively eliminating
colonization and restoring Beclin1 expression in ESCC patients may contribute to preventation and targeted treatment, and yield new insights into the aetiological research on ESCC.
The emergence of
(X) genes has compromised the clinical use of the last-line antibiotic tigecycline. We identified 322 (1.21%)
(X) positive samples from 12,829 human microbiome samples distributed in ...four continents (Asia, Europe, North America, and South America) using retrospective data from worldwide. These
(X) genes were dominated by
(X2)-like orthologs but we also identified 12 samples carrying novel
(X) genes, designed
(X45),
(X46), and
(X47), were resistant to tigecycline. The metagenomic analysis indicated these
(X) genes distributed in anaerobes dominated by
(78.89%) of human-gut origin. Two mobile elements IS
and IS
were most likely to promote the transmission of these
(X2)-like orthologs between
and Riemerella anatipestifer.
(X2)-like orthologs was also developed during transmission by mutation to high-level tigecycline resistant genes
(X45),
(X46), and
(X47). Further tracing these
(X) in single bacterial isolate from public repository indicated
(X) genes were present as early as 1960s in R. anatipestifer that was the primary
(X) carrier at early stage (before 2000). The
(X2) and non-
(X2) orthologs were primarily distributed in humans and food animals respectively, and non-
(X2) were dominated by
(X3) and
(X4). Genomic comparison indicated these
(X) genes were likely to be generated during
(X) transmission between
and E. coli/Acinetobacter spp., and IS
played a key role in the transmission. These results suggest R. anatipestifer was the potential ancestral source of
(X). In addition,
of human-gut origin was an important hidden reservoir and mutational incubator for the mobile
(X) genes that enabled spread to facultative anaerobes and aerobes.
The emergence of the tigecycline resistance gene
(X) has posed a severe threat to public health. However, reports of its origin and distribution in human remain rare. Here, we explore the origin and distribution of
(X) from large-scale metagenomic data of human-gut origin and public repository. This study revealed the emergency of
(X) gene in 1960s, which has refreshed a previous standpoint that the earliest presence of
(X) was in 1980s. The metagenomic analysis from data mining covered the unculturable bacteria, which has overcome the traditional bacteria isolating and purificating technologies, and the analysis indicated that the
of human-gut origin was an important hidden reservoir for
(X) that enabled spread to facultative anaerobes and aerobes. The continuous monitoring of mobile tigecycline resistance determinants from both culturable and unculturable microorganisms is imperative for understanding and tackling the dissemination of
(X) genes in both the health care and agricultural sectors.
High proportions of autistic children suffer from gastrointestinal (GI) disorders, implying a link between autism and abnormalities in gut microbial functions. Increasing evidence from recent ...high-throughput sequencing analyses indicates that disturbances in composition and diversity of gut microbiome are associated with various disease conditions. However, microbiome-level studies on autism are limited and mostly focused on pathogenic bacteria. Therefore, here we aimed to define systemic changes in gut microbiome associated with autism and autism-related GI problems. We recruited 20 neurotypical and 20 autistic children accompanied by a survey of both autistic severity and GI symptoms. By pyrosequencing the V2/V3 regions in bacterial 16S rDNA from fecal DNA samples, we compared gut microbiomes of GI symptom-free neurotypical children with those of autistic children mostly presenting GI symptoms. Unexpectedly, the presence of autistic symptoms, rather than the severity of GI symptoms, was associated with less diverse gut microbiomes. Further, rigorous statistical tests with multiple testing corrections showed significantly lower abundances of the genera Prevotella, Coprococcus, and unclassified Veillonellaceae in autistic samples. These are intriguingly versatile carbohydrate-degrading and/or fermenting bacteria, suggesting a potential influence of unusual diet patterns observed in autistic children. However, multivariate analyses showed that autism-related changes in both overall diversity and individual genus abundances were correlated with the presence of autistic symptoms but not with their diet patterns. Taken together, autism and accompanying GI symptoms were characterized by distinct and less diverse gut microbial compositions with lower levels of Prevotella, Coprococcus, and unclassified Veillonellaceae.
The complement system is a network of interacting fluid-phase and cell surface-associated molecules that trigger, amplify, and regulate immune and inflammatory signaling pathways. Dysregulation of ...this finely balanced network can destabilize host-microbe homeostasis and cause inflammatory tissue damage. Evidence from clinical and animal model-based studies suggests that complement is implicated in the pathogenesis of periodontitis, a polymicrobial community-induced chronic inflammatory disease that destroys the tooth-supporting tissues. This review discusses molecular mechanisms of complement involvement in the dysbiotic transformation of the periodontal microbiome and the resulting destructive inflammation, culminating in loss of periodontal bone support. These mechanistic studies have additionally identified potential therapeutic targets. In this regard, interventional studies in preclinical models have provided proof-of-concept for using complement inhibitors for the treatment of human periodontitis.
The development of antibiotics cannot keep up with the speed of resistance acquired by microorganisms. Recently, the development of antimicrobial photodynamic therapy (aPDT) has been a necessary ...antimicrobial strategy against antibiotic resistance. Among the wide variety of bacteria found in the oral flora, Porphyromonas gingivalis (P. gingivalis) is one of the etiological agents of periodontal disease. aPDT has been studied for periodontal disease, but has risks of cytotoxicity to normal stained tissue. In this study, we performed aPDT using protoporphyrin IX (PpIX), an intracellular pigment of P. gingivalis, without an external photosensitizer. We confirmed singlet oxygen generation by PpIX in a blue-light irradiation intensity-dependent manner. We discovered that blue-light irradiation on P. gingivalis is potentially bactericidal. The sterilization mechanism seems to be oxidative DNA damage in bacterial cells. Although it is said that no resistant bacteria will emerge using aPDT, the conventional method relies on an added photosensitizer dye. PpIX in P. gingivalis is used in energy production, so aPDT applied to PpIX of P. gingivalis should limit the appearance of resistant bacteria. This approach not only has potential as an effective treatment for new periodontal diseases, but also offers potential antibacterial treatment for multiple drug resistant bacteria.
MicroRNAs (miRNAs) are short, noncoding RNAs involved in the regulation of several processes associated with inflammatory diseases and infection. Bacterial infection modulates miRNA expression to ...subvert any innate immune response. In this study we analyzed, using microarray analysis, the bacterial modulation of miRNAs in bone marrow-derived macrophages (BMMs) in which activity was induced by infection with
The expression of several miRNAs was modulated 3 h postinfection (at a multiplicity of infection of 25). A bioinformatic analysis was performed to further identify pathways related to the innate immune host response under the influence of selected miRNAs. To assess the effects of the miRNAs identified on cytokine secretion (tumor necrosis factor alpha TNF-α and interleukin-10 IL-10), BMMs were transfected with selected miRNA mimics and inhibitors. Transfection with mmu-miR-155 and mmu-miR-2137 did not modify TNF-α secretion, while their inhibitors increased it. Inhibitors of mmu-miR-2137 and mmu-miR-7674 increased the secretion of the anti-inflammatory factor IL-10. In
-infected BMMs, mmu-miR-155-5p significantly decreased TNF-α secretion while inhibitor of mmu-miR-2137 increased IL-10 secretion.
, in a mouse model of
-induced calvarial bone resorption, injection of mmu-miR-155-5p or anti-mmu-miR-2137 reduced the size of the lesion significantly. Furthermore, anti-mmu-miR-2137 significantly reduced inflammatory cell infiltration, osteoclast activity, and bone loss. Bioinformatic analysis demonstrated that pathways related to cytokine- and chemokine-related pathways but also osteoclast differentiation may be involved in the effects observed. This study contributes further to our understanding of
-induced modulation of miRNAs and their physiological effects. It highlights the potential therapeutic merits of targeting mmu-miR-155-5p and mmu-miR-2137 to control inflammation induced by
infection.
The immune-regulatory B7-H1 receptor, also known as programmed death-ligand 1 (PD-L1), plays an important role in cell-mediated immune response. It is a co-signaling molecule that mediates regulation ...of T cell activation and tolerance and is able to negatively regulate activated T cell functions and survival. High expression of B7-H1 in host cells may contribute to the chronicity of inflammatory disorders and represents a possible mechanism of immune evasion. Porphyromonas gingivalis is regarded as a keystone pathogen in periodontitis and is able to invade host cells and disposes a variety of virulence factors including lipopolysaccharide (LPS), fimbriae and proteases such as gingipains. Based on previous studies that demonstrated the capability of P. gingivalis to induce up-regulation of PD-L1 in malignant and non-malignant oral epithelial cells, the aim of the present work was to analyse the potential of various cellular components of P. gingivalis to induce the PD-L1 receptor. Human squamous carcinoma cells and primary gingival keratinocytes were stimulated with total, inner and outer membrane fractions, cytosolic proteins, as well as LPS and peptidoglycans. PD-L1 protein expression was investigated by Western blot analysis and RT-PCR. It was demonstrated that the total membrane fraction induced the highest up-regulation in B7-H1 expression, followed by the outer and inner membrane, whereas cytosolic proteins and LPS did not. In conclusion, we provide evidence that the membrane fraction of P. gingivalis is responsible for up-regulation of the immune-regulatory receptor PD-L1 in squamous carcinoma cells and gingival keratinocytes, and thus may support immune evasion of oral carcinomas.
The opportunistic pathogen Escherichia coli, a common member of the human gut microbiota belonging to the Enterobacteriaceae family, is the causative agent of the majority of urinary tract infections ...(UTIs). The gut microbiota serves as a reservoir for uropathogenic E. coli where they are shed in feces, colonize the periurethral area, and infect the urinary tract. Currently, front line treatment for UTIs consists of oral antibiotics, but the rise of antibiotic resistance is leading to higher rates of recurrence, and antibiotics cause collateral damage to other members of the gut microbiota. It is commonly believed that incorporation of the American cranberry, Vaccinium macrocarpon, into the diet is useful for reducing recurrence of UTIs. We hypothesized such a benefit might be explained by a prebiotic or antimicrobial effect on the gut microbiota. As such, we tested cranberry extracts and whole cranberry powder on a human gut microbiome-derived community in a gut simulator and found that cranberry components broadly modulate the microbiota by reducing the abundance of Enterobacteriaceae and increasing the abundance of Bacteroidaceae. To identify the specific compounds responsible for this, we tested a panel of compounds isolated from cranberries for activity against E. coli, and found that salicylate exhibited antimicrobial activity against both laboratory E. coli and human UTI E. coli isolates. In a gut simulator, salicylate reduced levels of Enterobacteriaceae and elevated Bacteroidaceae in a dose dependent manner.
Chronic periodontitis (CP) is a microbial dysbiotic disease linked to increased risk of oral squamous cell carcinomas (OSCCs). To address the underlying mechanisms, mouse and human cell infection ...models and human biopsy samples were employed. We show that the 'keystone' pathogen Porphyromonas gingivalis, disrupts immune surveillance by generating myeloid-derived dendritic suppressor cells (MDDSCs) from monocytes. MDDSCs inhibit CTLs and induce FOXP3 + T
through an anti-apoptotic pathway. This pathway, involving pAKT1, pFOXO1, FOXP3, IDO1 and BIM, is activated in humans with CP and in mice orally infected with Mfa1 expressing P. gingivalis strains. Mechanistically, activation of this pathway, demonstrating FOXP3 as a direct FOXO1-target gene, was demonstrated by ChIP-assay in human CP gingiva. Expression of oncogenic but not tumor suppressor markers is consistent with tumor cell proliferation demonstrated in OSCC-P. gingivalis cocultures. Importantly, FimA + P. gingivalis strain MFI invades OSCCs, inducing inflammatory/angiogenic/oncogenic proteins stimulating OSCCs proliferation through CXCR4. Inhibition of CXCR4 abolished Pg-MFI-induced OSCCs proliferation and reduced expression of oncogenic proteins SDF-1/CXCR4, plus pAKT1-pFOXO1. Conclusively, P. gingivalis, through Mfa1 and FimA fimbriae, promotes immunosuppression and oncogenic cell proliferation, respectively, through a two-hit receptor-ligand process involving DC-SIGN
/CXCR4
, activating a pAKT
pFOXO1
BIM
FOXP3
and IDO
- driven pathway, likely to impact the prognosis of oral cancers in patients with periodontitis.
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