ABSTRACT
Fusobacterium nucleatum can bind to host cells and potentiate intestinal tumorigenesis. Here we used a genome-wide screen to identify an adhesin, RadD, which facilitates the attachment of F. nucleatum to colorectal cancer (CRC) cells in vitro. RadD directly binds to CD147, a receptor overexpressed on CRC cell surfaces, which initiated a PI3K-AKT-NF-κB-MMP9 cascade, subsequently enhancing tumorigenesis in mice. Clinical specimen analysis showed that elevated radD gene levels in CRC tissues correlated positively with activated oncogenic signalling and poor patient outcomes. Finally, blockade of the interaction between RadD and CD147 in mice effectively impaired F. nucleatum attachment and attenuated F. nucleatum-induced oncogenic response. Together, our study provides insights into an oncogenic mechanism driven by F. nucleatum RadD and suggests that the RadD-CD147 interaction could be a potential therapeutic target for CRC.
Subject(s)
Adhesins, Bacterial , Bacterial Adhesion , Basigin , Carcinogenesis , Colorectal Neoplasms , Fusobacterium nucleatum , Fusobacterium nucleatum/pathogenicity , Fusobacterium nucleatum/genetics , Fusobacterium nucleatum/physiology , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/pathology , Animals , Humans , Mice , Basigin/metabolism , Basigin/genetics , Adhesins, Bacterial/metabolism , Adhesins, Bacterial/genetics , Carcinogenesis/genetics , Cell Line, Tumor , Fusobacterium Infections/microbiology , Fusobacterium Infections/complications , Matrix Metalloproteinase 9/metabolism , Matrix Metalloproteinase 9/genetics , Signal Transduction , NF-kappa B/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Phosphatidylinositol 3-Kinases/genetics , FemaleABSTRACT
OBJECTIVES: Periodontitis is associated with Fusobacterium nucleatum (F.n) infection. Although the colonization of renal tissue by F.n is well documented, its specific role in kidney disease has yet to be determined. This study aimed to investigate the potential association between F.n-induced periodontitis and renal interstitial fibrosis. METHODS: The rat gingival sulcus was injected with F.n suspension, while the control group (NC) was injected with PBS. The levels of total protein (TP), albumin (ALB), creatinine, and urea nitrogen (BUN) in rat serum and/or urine were quantified using the appropriate kits. Renal interstitial fibrosis and epithelial-mesenchymal transition (EMT) were evaluated in rats using Masson staining, Periodic Schiff-Methenamine (PASM) staining, and immunohistochemical staining. The levels of fibrosis- and EMT-related proteins and the TGF-ß/SMAD2/3 and ß-catenin signaling pathways were determined using Western blot analysis. F.n in the kidney tissues was quantitatively determined using bacterial 16S rRNA technology. RESULTS: Serum levels of TP, ALB, creatinine, and BUN were not significantly decreased in F.n-infected rats with periodontitis. The levels of creatinine and ALB in the urine were not statistically different between two groups. Masson and PASM staining showed that F.n-induced periodontitis could promote renal interstitial fibrosis in rats. The levels of collagen I, fibronectin (FN), vimentin, and α-SMA were upregulated in the kidney tissues of rats with F.n-induced periodontitis and in F.n-treated HK-2 cells. However, E-cadherin levels were reduced. F.n promoted renal interstitial and HK-2 cell fibrosis in rats by modulating the TGF-ß/SMAD2/3 and ß-catenin signaling pathways. F.n colonization increased renal interstitial fibrosis in rats. CONCLUSION: F.n-induced periodontitis promoted EMT by activating the TGF-ß/SMAD2/3 and ß-catenin signaling pathways, thus promoting renal interstitial fibrosis in rats.
Subject(s)
Epithelial-Mesenchymal Transition , Fibrosis , Fusobacterium nucleatum , Kidney , Periodontitis , Signal Transduction , Smad2 Protein , Smad3 Protein , Transforming Growth Factor beta , beta Catenin , Animals , Fusobacterium nucleatum/pathogenicity , beta Catenin/metabolism , Rats , Periodontitis/microbiology , Periodontitis/complications , Periodontitis/pathology , Periodontitis/metabolism , Male , Transforming Growth Factor beta/metabolism , Smad3 Protein/metabolism , Kidney/pathology , Kidney/metabolism , Smad2 Protein/metabolism , Kidney Diseases/metabolism , Kidney Diseases/microbiology , Kidney Diseases/pathology , Kidney Diseases/etiology , Fusobacterium Infections/complications , Fusobacterium Infections/metabolism , Rats, Sprague-DawleyABSTRACT
Sialic acid metabolism in oral bacteria is a complex process involving nutrient acquisition, immune evasion, cell surface modification, and the production of metabolites that contribute to bacterial persistence and virulence in the oral cavity. In addition to causing various periodontal diseases, certain oral pathogenic bacteria, such as Porphyromonas gingivalis, Tannerella forsythia, and Fusobacterium nucleatum, can induce inflammatory reactions and influence the immunity of host cells. These associations with host cells are linked to various diseases, particularly colorectal cancer and Alzheimer's disease. Sialic acid can be found in the host oral mucosa, saliva, or food residues in the oral cavity, and it may promote the colonization of oral bacteria and contribute to disease development. This review aims to summarize the role of sialic acid metabolism in oral bacteria and discuss its effect on the pathogenesis of colorectal cancer and Alzheimer's disease.
Subject(s)
Alzheimer Disease , Colorectal Neoplasms , N-Acetylneuraminic Acid , Humans , Alzheimer Disease/metabolism , Alzheimer Disease/microbiology , N-Acetylneuraminic Acid/metabolism , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/microbiology , Mouth/microbiology , Bacteria/metabolism , Bacteria/pathogenicity , Fusobacterium nucleatum/metabolism , Fusobacterium nucleatum/pathogenicity , AnimalsABSTRACT
Fusobacterium nucleatum (F. nucleatum) is closely correlated with tumorigenesis in colorectal cancer (CRC). We aimed to investigate the effects of host norepinephrine on the carcinogenicity of F. nucleatum in CRC and reveal the underlying mechanism. The results revealed that both norepinephrine and bacterial quorum sensing (QS) molecule auto-inducer-2 (AI-2) were positively associated with the progression of F. nucleatum related CRC (p < 0.01). In vitro studies, norepinephrine induced upregulation of QS-associated genes and promoted the virulence and proliferation of F. nucleatum. Moreover, chronic stress significantly increased the colon tumour burden of ApcMin/+ mice infected with F. nucleatum (p < 0.01), which was decreased by a catecholamine inhibitor (p < 0.001). Our findings suggest that stress-induced norepinephrine may promote the progression of F. nucleatum related CRC via bacterial QS signalling. These preliminary data provide a novel strategy for the management of pathogenic bacteria by targeting host hormones-bacterial QS inter-kingdom signalling.
Subject(s)
Colorectal Neoplasms , Fusobacterium nucleatum , Norepinephrine , Quorum Sensing , Signal Transduction , Quorum Sensing/drug effects , Fusobacterium nucleatum/pathogenicity , Fusobacterium nucleatum/drug effects , Fusobacterium nucleatum/physiology , Animals , Colorectal Neoplasms/microbiology , Norepinephrine/pharmacology , Mice , Humans , Disease Progression , Fusobacterium Infections/microbiology , Virulence , Homoserine/analogs & derivatives , Homoserine/metabolism , Mice, Inbred C57BL , Male , LactonesABSTRACT
Fusobacterium nucleatum, a gram-negative oral bacterium, has been consistently validated as a strong contributor to the progression of several types of cancer, including colorectal (CRC) and pancreatic cancer. While previous in vitro studies have shown that intracellular F. nucleatum enhances malignant phenotypes such as cell migration, the dependence of this regulation on features of the tumor microenvironment (TME) such as oxygen levels are wholly uncharacterized. Here we examine the influence of hypoxia in facilitating F. nucleatum invasion and its effects on host responses focusing on changes in the global epigenome and transcriptome. Using a multiomic approach, we analyze epigenomic alterations of H3K27ac and global transcriptomic alterations sustained within a hypoxia and normoxia conditioned CRC cell line HCT116 at 24 h following initial infection with F. nucleatum. Our findings reveal that intracellular F. nucleatum activates signaling pathways and biological processes in host cells similar to those induced upon hypoxia conditioning in the absence of infection. Furthermore, we show that a hypoxic TME favors F. nucleatum invasion and persistence and therefore infection under hypoxia may amplify malignant transformation by exacerbating the effects induced by hypoxia alone. These results motivate future studies to investigate host-microbe interactions in tumor tissue relevant conditions that more accurately define parameters for targeted cancer therapies.
Subject(s)
Colorectal Neoplasms , Epigenome , Fusobacterium Infections , Fusobacterium nucleatum , Oxygen , Transcriptome , Humans , Fusobacterium nucleatum/genetics , Fusobacterium nucleatum/physiology , Fusobacterium nucleatum/pathogenicity , Colorectal Neoplasms/genetics , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , HCT116 Cells , Fusobacterium Infections/genetics , Fusobacterium Infections/microbiology , Fusobacterium Infections/metabolism , Oxygen/metabolism , Tumor Microenvironment/genetics , Gene Expression Regulation, NeoplasticABSTRACT
Periodontitis is linked to the onset and progression of oral squamous cell carcinoma (OSCC), an epidemiologically frequent and clinically aggressive malignancy. In this context, Fusobacterium (F.) nucleatum and Porphyromonas (P.) gingivalis, 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 P. gingivalis or F. nucleatum could have on cellular and molecular events involved in oral carcinogenesis. Results from the reviewed papers indicate that infection by P. gingivalis and/or F. nucleatum 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.
Subject(s)
Fusobacterium Infections , Fusobacterium nucleatum , Mouth Neoplasms , Porphyromonas gingivalis , Humans , Porphyromonas gingivalis/pathogenicity , Fusobacterium nucleatum/pathogenicity , Mouth Neoplasms/microbiology , Mouth Neoplasms/pathology , Fusobacterium Infections/microbiology , Fusobacterium Infections/complications , Carcinogenesis , Bacteroidaceae Infections/microbiology , Bacteroidaceae Infections/complications , Carcinoma, Squamous Cell/microbiology , Carcinoma, Squamous Cell/etiology , Carcinoma, Squamous Cell/pathology , Periodontitis/microbiology , Animals , Cytokines/metabolismABSTRACT
Gynecological and obstetric infectious diseases are crucial to women's health. There is growing evidence that links the presence of Fusobacterium nucleatum (F. nucleatum), an anaerobic oral commensal and potential periodontal pathogen, to the development and progression of various human diseases, including cancers. While the role of this opportunistic oral pathogen has been extensively studied in colorectal cancer in recent years, research on its epidemiological evidence and mechanistic link to gynecological diseases (GDs) is still ongoing. Thus, the present review, which is the first of its kind, aims to undertake a comprehensive and critical reappraisal of F. nucleatum, including the genetics and mechanistic role in promoting adverse pregnancy outcomes (APOs) and various GDs, including cancers. Additionally, this review discusses new conceptual advances that link the immunomodulatory role of F. nucleatum to the development and progression of breast, ovarian, endometrial, and cervical carcinomas through the activation of various direct and indirect signaling pathways. However, further studies are needed to explore and elucidate the highly dynamic process of host-F. nucleatum interactions and discover new pathways, which will pave the way for the development of better preventive and therapeutic strategies against this pathobiont.
Subject(s)
Fusobacterium nucleatum , Pregnancy Outcome , Humans , Female , Fusobacterium nucleatum/pathogenicity , Pregnancy , Fusobacterium Infections/complications , Fusobacterium Infections/microbiology , Genital Diseases, Female/microbiology , Neoplasms/microbiologyABSTRACT
Fusobacterium (F.) nucleatum is a carcinogenesis microbiota in colorectal cancer (CRC). Growing evidence shows that F. nucleatum contributes to chemoresistance. Ferroptosis is reported to restore the susceptibility of resistant cells to chemotherapy. However, the role of gut microbiota affecting ferroptosis in chemoresistance remains unclear. Here, we examined the CRC tissues of patients using 16S rRNA sequencing to investigate the possible connection between gut microbiota dysbiosis and the relapse of CRC. We found that a high abundance of F. nucleatum in CRC tissue is associated with relapse. We further demonstrated that F. nucleatum induced oxaliplatin resistance in vitro and in vivo. The transcriptome of an F. nucleatum-infected cell revealed ferroptosis was associated with F. nucleatum infection. We perform malondialdehyde, ferrous iron, and glutathione assays to verify the effect of F. nucleatum on ferroptosis under oxaliplatin treatment in vivo and in vitro. Mechanistically, F. nucleatum promoted oxaliplatin resistance by overexpressing GPX4 and then inhibiting ferroptosis. E-cadherin/ß-catenin/TCF4 pathway conducted the GPX4 overexpression effect of F. nucleatum. The chromatin immuno-precipitation quantitative PCR (CHIP-qPCR) and dual-luciferase reporter assay showed that F. nucleatum promoted TCF4 binding with GPX4. We also determined the E-cadherin/ß-catenin/TCF4/GPX4 axis related to tumor tissue F. nucleatum status and CRC relapse clinically. Here, we revealed the contribution of F. nucleatum to oxaliplatin resistance by inhibiting ferroptosis in CRC. Targeting F. nucleatum and ferroptosis will provide valuable insight into chemoresistance management and may improve outcomes for patients with CRC.
Subject(s)
Cadherins , Colorectal Neoplasms , Drug Resistance, Neoplasm , Ferroptosis , Fusobacterium nucleatum , Gastrointestinal Microbiome , Oxaliplatin , Phospholipid Hydroperoxide Glutathione Peroxidase , beta Catenin , Ferroptosis/drug effects , Ferroptosis/genetics , Humans , Colorectal Neoplasms/pathology , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/genetics , Cadherins/metabolism , Cadherins/genetics , Oxaliplatin/pharmacology , beta Catenin/metabolism , beta Catenin/genetics , Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism , Phospholipid Hydroperoxide Glutathione Peroxidase/genetics , Animals , Fusobacterium nucleatum/pathogenicity , Mice , Gastrointestinal Microbiome/drug effects , Xenograft Model Antitumor Assays , Gene Expression Regulation, Neoplastic/drug effects , Male , Antigens, CD/metabolism , Antigens, CD/genetics , Female , Cell Line, Tumor , Fusobacterium Infections/microbiology , Fusobacterium Infections/drug therapy , Fusobacterium Infections/metabolism , Fusobacterium Infections/genetics , Fusobacterium Infections/pathology , Dysbiosis/microbiology , Transcription Factor 4/metabolism , Transcription Factor 4/genetics , Mice, NudeSubject(s)
Colorectal Neoplasms , Fusobacterium Infections , Fusobacterium nucleatum , Humans , Colorectal Neoplasms/complications , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/pathology , Gastrointestinal Microbiome , Fusobacterium nucleatum/genetics , Fusobacterium nucleatum/isolation & purification , Fusobacterium nucleatum/pathogenicity , Fusobacterium Infections/complications , Fusobacterium Infections/genetics , Fusobacterium Infections/microbiologyABSTRACT
Fusobacterium nucleatum (Fn), a bacterium present in the human oral cavity and rarely found in the lower gastrointestinal tract of healthy individuals1, is enriched in human colorectal cancer (CRC) tumours2-5. High intratumoural Fn loads are associated with recurrence, metastases and poorer patient prognosis5-8. Here, to delineate Fn genetic factors facilitating tumour colonization, we generated closed genomes for 135 Fn strains; 80 oral strains from individuals without cancer and 55 unique cancer strains cultured from tumours from 51 patients with CRC. Pangenomic analyses identified 483 CRC-enriched genetic factors. Tumour-isolated strains predominantly belong to Fn subspecies animalis (Fna). However, genomic analyses reveal that Fna, considered a single subspecies, is instead composed of two distinct clades (Fna C1 and Fna C2). Of these, only Fna C2 dominates the CRC tumour niche. Inter-Fna analyses identified 195 Fna C2-associated genetic factors consistent with increased metabolic potential and colonization of the gastrointestinal tract. In support of this, Fna C2-treated mice had an increased number of intestinal adenomas and altered metabolites. Microbiome analysis of human tumour tissue from 116 patients with CRC demonstrated Fna C2 enrichment. Comparison of 62 paired specimens showed that only Fna C2 is tumour enriched compared to normal adjacent tissue. This was further supported by metagenomic analysis of stool samples from 627 patients with CRC and 619 healthy individuals. Collectively, our results identify the Fna clade bifurcation, show that specifically Fna C2 drives the reported Fn enrichment in human CRC and reveal the genetic underpinnings of pathoadaptation of Fna C2 to the CRC niche.
Subject(s)
Colorectal Neoplasms , Fusobacterium nucleatum , Animals , Humans , Mice , Adenoma/microbiology , Case-Control Studies , Colorectal Neoplasms/microbiology , Colorectal Neoplasms/pathology , Feces/microbiology , Fusobacterium nucleatum/classification , Fusobacterium nucleatum/genetics , Fusobacterium nucleatum/isolation & purification , Fusobacterium nucleatum/pathogenicity , Gastrointestinal Tract/metabolism , Gastrointestinal Tract/microbiology , Genome, Bacterial/genetics , Mouth/microbiology , FemaleABSTRACT
BACKGROUND: Cancer impacts millions of lives globally each year, with approximately 10 million cancer-related deaths recorded worldwide in 2020. Mounting research has recognised the human microbiome as a key area of interest in the pathophysiology of various human diseases including cancer tumorigenesis, progression and in disease outcome. It is suggested that approximately 20% of human cancers may be linked to microbes. Certain residents of the human microbiome have been identified as potentially playing a role, including: Helicobacter pylori, Fusobacterium nucleatum, Escherichia coli, Bacteroides fragilis and Porphyromonas gingivalis. MAIN BODY: In this review, we explore the current evidence that indicate a link between the human microbiome and cancer. Microbiome compositional changes have been well documented in cancer patients. Furthermore, pathogenic microbes harbouring specific virulence factors have been implicated in driving the carcinogenic activity of various malignancies including colorectal, gastric and pancreatic cancer. The associated genetic mechanisms with possible roles in cancer will be outlined. It will be indicated which microbes have a potential direct link with cancer cell proliferation, tumorigenesis and disease progression. Recent studies have also linked certain microbial cytotoxins and probiotic strains to cancer cell death, suggesting their potential to target the tumour microenvironment given that cancer cells are integral to its composition. Studies pertaining to such cytotoxic activity have suggested the benefit of microbial therapies in oncological treatment regimes. It is also apparent that bacterial pathogenic protein products encoded for by certain loci may have potential as oncogenic therapeutic targets given their possible role in tumorigenesis. CONCLUSION: Research investigating the impact of the human microbiome in cancer has recently gathered pace. Vast amounts of evidence indicate the human microbiome as a potential player in tumorigenesis and progression. Promise in the development of cancer biomarkers and in targeted oncological therapies has also been demonstrated, although more studies are needed. Despite extensive in vitro and in vivo research, clinical studies involving large cohorts of human patients are lacking. The current literature suggests that further intensive research is necessary to validate both the role of the human microbiome in cancer, and the use of microbiome modification in cancer therapy.
Subject(s)
Carcinogenesis/genetics , Colorectal Neoplasms/therapy , Microbiota/genetics , Animals , Bacteroides fragilis/genetics , Bacteroides fragilis/pathogenicity , Carcinogenesis/pathology , Fusobacterium nucleatum/genetics , Fusobacterium nucleatum/pathogenicity , Gastrointestinal Microbiome/genetics , Gastrointestinal Microbiome/physiology , Humans , Mice , Microbiota/physiology , Probiotics , Tumor Microenvironment , Virulence FactorsABSTRACT
Periodontitis is prevalent in half of the adult population and raises critical health concerns as it has been recently associated with an increased risk of cancer. While information about the topic remains somewhat scarce, a deeper understanding of the underlying mechanistic pathways promoting neoplasia in periodontitis patients is of fundamental importance. This manuscript presents the literature as well as a panel of tables and figures on the molecular mechanisms of Porphyromonas gingivalis and Fusobacterium nucleatum, two main oral pathogens in periodontitis pathology, involved in instigating tumorigenesis. We also present evidence for potential links between the RANKL-RANK signaling axis as well as circulating cytokines/leukocytes and carcinogenesis. Due to the nonconclusive data associating periodontitis and cancer reported in the case and cohort studies, we examine clinical trials relevant to the topic and summarize their outcome.
Subject(s)
Mouth Neoplasms/microbiology , Periodontal Diseases/microbiology , RANK Ligand/metabolism , Receptor Activator of Nuclear Factor-kappa B/metabolism , Cytokines/metabolism , Disease Progression , Fusobacterium nucleatum/pathogenicity , Gene Expression Regulation , Humans , Mouth Neoplasms/metabolism , Periodontal Diseases/metabolism , Porphyromonas gingivalis/pathogenicity , Signal TransductionABSTRACT
Fusobacterium nucleatum, found in the oral cavity, influences the progression of gastrointestinal cancers. Additionally, our previous results suggested that F. nucleatum is associated with poor patient prognosis in esophageal squamous cell carcinoma (ESCC). However, the mechanism by which F. nucleatum affects aggressive tumor behavior has yet to be elucidated. We have conducted this clinical, in vitro, and in vivo study to clarify the mechanism of ESCC progression induced by F. nucleatum. Transmission electron microscopy revealed that F. nucleatum invaded and occupied ESCC cells and impacted gene and protein expression. Comprehensive mRNA expression and pathway enrichment analyses of F. nucleatum-treated ESCC cells identified the "NF-κB" and "NOD-like receptor" signaling pathways as enriched. We confirmed the relationship between the presence of F. nucleatum and NF-κB activation in resected ESCC tissues. Furthermore, F. nucleatum-treated ESCC cells demonstrated enhanced growth ability, and NF-κB activation, as well as overexpression of NOD1 and phosphorylated RIPK2. Furthermore, treated cells showed accelerated tumor growth, with NF-κB activation in xenograft models. F. nucleatum invaded ESCC cells and induced the NF-κB pathway through the NOD1/RIPK2 pathway, leading to tumor progression.
Subject(s)
Esophageal Neoplasms/microbiology , Esophageal Squamous Cell Carcinoma/microbiology , Fusobacterium Infections/metabolism , Fusobacterium nucleatum/pathogenicity , NF-kappa B/metabolism , Nod1 Signaling Adaptor Protein/metabolism , Receptor-Interacting Protein Serine-Threonine Kinase 2/metabolism , Animals , Cell Line, Tumor , Disease Progression , Esophageal Neoplasms/metabolism , Esophageal Neoplasms/pathology , Esophageal Squamous Cell Carcinoma/metabolism , Esophageal Squamous Cell Carcinoma/pathology , Female , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Signal Transduction/physiologyABSTRACT
OBJECTIVE: Uncontrolled production of Interleukin-1ß (IL-1ß), a major proinflammatory cytokine, is associated with tissue destruction in periodontal disease. IL-1ß production is controlled by inflammasomes which are multiprotein regulatory complexes. The current study aimed to elucidate potential regulatory pathways by monitoring the effects of periodontal pathogens Fusobacterium nucleatum (Fn) and Porphyromonas gingivalis (Pg) on inflammasomes and their regulators in human gingival fibroblasts (HGFs) in vitro. METHODS: HGFs were exposed to Fn and Pg alone or in combination for 24 hr at a multiplicity of infection of 100, ±30 min exposure with 5 mM adenosine triphosphate (ATP) incubation. Gene expression of NLRP3 and AIM2, inflammasome regulatory proteins POP1, CARD16 and TRIM16, and inflammasome components ASC and CASPASE 1, and IL-1ß, were evaluated by RT-PCR. Pro- and mature IL-1ß levels were monitored intracellularly by immunocytochemistry and extracellularly by ELISA. RESULTS: Fn + ATP significantly upregulated NLRP3, AIM2, IL-1ß, ASC, and CASPASE 1; however, it downregulated POP1 and TRIM16. Pg + ATP downregulated NLRP3, ASC, POP1, but upregulated IL-1ß and CARD16. Pg + Fn+ATP significantly upregulated AIM2, IL-1ß and CARD16, and downregulated POP1, TRIM16, and CASPASE 1. Pg + ATP exposure significantly increased pro- and mature IL-1ß production. CONCLUSION: Bacterial exposure with ATP may deregulate IL-1ß by dysregulating inflammasomes and their regulators in HGFs.
Subject(s)
Fibroblasts/immunology , Inflammasomes , NLR Family, Pyrin Domain-Containing 3 Protein , Cells, Cultured , Fibroblasts/microbiology , Fusobacterium nucleatum/pathogenicity , Gingiva/cytology , Humans , Interleukin-1beta , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Porphyromonas gingivalis/pathogenicityABSTRACT
As a potential biomarker, there is increasing evidence showing that Fusobacterium nucleatum is positively correlated with the occurrence and development of colorectal cancer. Although antibiotics were expected to eliminate F. nucleatum, the side effects associated with gut microbiotal disorders have to be considered. Here, by performing shotgun metagenomic and transcriptome sequencing, we systematically evaluated the antagonistic effects of probiotic Lactiplantibacillus plantarum HNU082 (Lp082) on F. nucleatum in vivo and in vitro. The results showed that the F. nucleatum invasion significantly altered the host intestinal microbiome including the microbial composition, specific species, metabolic pathways and metabolites, as well as impacted the transcriptome of the intestinal epithelial cells. Moreover, the F. nucleatum invasion triggered inflammatory cytokines and inflammatory responses in the intestine but did not develop into colorectal cancer. Excitingly, the Lp082 intervention inhibited the growth of F. nucleatum both in vivo and in vitro and alleviated the inflammatory response introduced by F. nucleatum invasion. Further network-based mechanism exploration demonstrated that Lp082, which negatively correlated to F. nucleatum, maintained the intestinal microbiome homeostasis and prompted the production of beneficial metabolites in the intestine which decreased the expression of inflammatory cytokines in a mouse model. The present research suggested a feasible probiotic intervention strategy for F. nucleatum antagonism in vivo, which may prevent colorectal cancer at the early stage.
Subject(s)
Fusobacterium nucleatum/physiology , Lactobacillaceae , Probiotics/pharmacology , Animals , Biomarkers, Tumor , Fusobacterium nucleatum/pathogenicity , Gastrointestinal Microbiome , Gene Expression Regulation, Bacterial , Genes, Bacterial , Inflammation , Male , Metagenomics , Mice , Mice, Inbred C57BL , TranscriptomeABSTRACT
Species (spp.) belonging to the genus Fusobacterium are anaerobic commensals colonizing the upper respiratory tract, the gastrointestinal tract, and the genitals. Infections with Fusobacterium spp. have been reported at many anatomical sites, including pneumonias and pleural empyemas; however, there are very few published cases of Fusobacterium spp. causing spondylodiscitis or fistulas. Bone infections with Fusobacterium can spread directly to surrounding muscular tissue or by hematogenous transmission to any other tissue including pleurae and lungs. Similarly, pleural infections can spread Fusobacterium spp. to any other tissue including fistulas and bone. Concomitant pleural empyema and spondylodiscitis are rare; however, there are a few published cases with concomitant disease, although none caused by Fusobacterium spp. A 77-year-old female patient was assessed using computed tomography (CT) scanning of the thorax and abdomen, as well as analyses of fluid drained from the region affected by the pleural empyema. A diagnosis of Fusobacterium empyema, fistula, bacteremia, and spondylodiscitis was made, and the patient's condition improved significantly after drainage of the pleural empyema and relevant long-term antibiotic treatment. We describe the first confirmed case with concomitant infection with Fusobacterium nucleatum as spondylodiscitis and pleural empyema connected by a fistula.
Subject(s)
Discitis/etiology , Empyema, Pleural/etiology , Fistula/etiology , Fusobacterium Infections/complications , Fusobacterium nucleatum/pathogenicity , Aged , Anti-Bacterial Agents/therapeutic use , Bacteremia/diagnosis , Bacteremia/drug therapy , Bacteremia/etiology , Discitis/diagnosis , Discitis/drug therapy , Empyema, Pleural/diagnosis , Empyema, Pleural/drug therapy , Female , Fistula/diagnosis , Fistula/drug therapy , Fusobacterium Infections/diagnosis , Fusobacterium Infections/drug therapy , Fusobacterium nucleatum/drug effects , Humans , Pleura/diagnostic imaging , Pleura/microbiology , Treatment OutcomeABSTRACT
The ability of cancer cells to undergo partial-epithelial mesenchymal transition (p-EMT), rather than complete EMT, poses a higher metastatic risk. Although Fusobacterium nucleatum mainly inhabits in oral cavity, attention has been focused on the F. nucleatum involvement in colorectal cancer development. Here we examined the p-EMT regulation by F. nucleatum in oral squamous cell carcinoma (OSCC) cells. We cultured OSCC cells with epithelial, p-EMT or EMT phenotype with live or heat-inactivated F. nucleatum. Expression of the genes involved in epithelial differentiation, p-EMT and EMT were examined in OSCC cells after co-culture with F. nucleatum by qPCR. Cell growth and invasion of OSCC cells were also examined. Both live and heat-inactivated F. nucleatum upregulated the expression of p-EMT-related genes in OSCC cells with epithelial phenotype, but not with p-EMT or EMT phenotype. Moreover, F. nucleatum promoted invasion of OSCC cells with epithelial phenotype. Co-culture with other strains of bacteria other than Porphyromonas gingivalis did not alter p-EMT-related genes in OSCC cells with epithelial phenotype. F. nucleatum infection may convert epithelial to p-EMT phenotype via altering gene expression in OSCC. Oral hygiene managements against F. nucleatum infection may contribute to reduce the risk for an increase in metastatic ability of OSCC.
Subject(s)
Biomarkers, Tumor/genetics , Carcinoma, Squamous Cell/virology , Fusobacterium Infections/complications , Fusobacterium nucleatum/pathogenicity , Mouth Neoplasms/virology , Carcinoma, Squamous Cell/genetics , Cell Line, Tumor , Cell Movement , Cell Proliferation , Disease Progression , Epithelial-Mesenchymal Transition , Fusobacterium Infections/genetics , Gene Expression Regulation, Neoplastic , Humans , Mouth Neoplasms/genetics , Neoplasm Metastasis , Oral HygieneABSTRACT
OBJECTIVE: The human being has evolved in close symbiosis with its own ecological community of commensal, symbiotic and pathogenic bacteria. After the intestinal microbiome, that of the oral cavity is the largest and most diversified. Its importance is reflected not only in local and systemic diseases, but also in pregnancy since it would seem to influence the placental microbiome. MATERIALS AND METHODS: This is a literature review of articles published in PubMed about Fusobacterium Nucleatum and both its implications with systemic and oral health, adverse pregnancy outcomes, flavors perception and its interference in the oral-nasal mucosal immunity. RESULTS: It is in maintaining the microbiome's homeostasis that the Fusobacterium nucleatum, an opportunistic periodontal pathogen of the oral cavity, plays a crucial role both as a bridge microorganism of the tongue biofilm, and in maintaining the balance between the different species in the oral-nasal mucosal immunity also by taste receptors interaction. It is also involved in the flavor perception and its detection in the oral microbiome of children from the first days of life suggests a possible physiological role. However, the dysbiosis can determine its pathogenicity with local and systemic consequences, including the pathogenesis of respiratory infections. CONCLUSIONS: It is interesting to evaluate its possible correlation with Sars-CoV-2 and the consequences on the microflora of the oral cavity, both to promote a possible broad-spectrum preventive action, in favor of all subjects for whom, by promoting the eubiosis of the oral microbiome, a defensive action could be envisaged by the commensals themselves but, above all, for patients with specific comorbidities and therefore already prone to oral dysbiosis.
Subject(s)
COVID-19/microbiology , Fusobacterium nucleatum/isolation & purification , Mouth/microbiology , COVID-19/immunology , Female , Fusobacterium nucleatum/immunology , Fusobacterium nucleatum/pathogenicity , Humans , Mouth/immunology , PregnancyABSTRACT
A variety of pathogenic microorganisms promote tumor occurrence and development through long-term colonization in the body. Fusobacterium nucleatum (F. nucleatum) is abundant in precancerous esophageal lesions and is closely related to the malignant progression of esophageal squamous cell carcinoma (ESCC). The invasion of exogenous microorganisms can reshape the immune microenvironment, make the immune system incapacitated, and assist tumor cells in immune escape. A variety of pathogenic microorganisms induce the recruitment of regulatory T cell (Tregs) to allow tumor cells to escape immune surveillance and provide favorable conditions for their own long-term colonization. Tregs are one of the major obstacles to tumor immunotherapy and have a significant positive correlation with the occurrence and development of many kinds of tumors. Because F. nucleatum can instantly enter cells and colonize for a long time, we speculated that F. nucleatum infection could facilitate the immune escape of tumor cells through enrichment of Tregs and promote the malignant progression of ESCC. In this study, we found a significant concordance between F. nucleatum infection and Tregs infiltration. Therefore, we propose the view that chronic infection of F. nucleatum may provide favorable conditions for long-term colonization of itself by recruiting Tregs and suppressing the immune response. At the same time, the massive enrichment of Treg may also weaken the immune response and assist in the long-term colonization of F. nucleatum. We analyzed the correlation between F. nucleatum infection with the clinicopathological characteristics and survival prognosis of the patients. F. nucleatum infection was found to be closely related to sex, smoking, drinking, degree of differentiation, depth of invasion, lymph node metastasis, and clinical stage. The degree of differentiation, depth of infiltration, lymph node metastasis, clinical stage, and F. nucleatum infection are independent risk factors affecting ESCC prognosis. Additionally, the survival rate and median survival time were significantly shortened in the F. nucleatum infection positive group. Therefore, we propose that long-term smoking and alcohol consumption cause poor oral and esophageal environments, thereby significantly increasing the risk of F. nucleatum infection. In turn, F. nucleatum infection and colonization may weaken the antitumor immune response through Treg enrichment and further assist in self-colonization, promoting the malignant progression of ESCC.
Subject(s)
Esophageal Neoplasms/pathology , Esophageal Squamous Cell Carcinoma/pathology , Fusobacterium Infections/complications , Fusobacterium nucleatum/pathogenicity , T-Lymphocytes, Regulatory/immunology , Tumor Microenvironment , Esophageal Neoplasms/immunology , Esophageal Neoplasms/microbiology , Esophageal Neoplasms/surgery , Esophageal Squamous Cell Carcinoma/immunology , Esophageal Squamous Cell Carcinoma/microbiology , Esophageal Squamous Cell Carcinoma/surgery , Female , Follow-Up Studies , Fusobacterium Infections/microbiology , Humans , Lymphatic Metastasis , Male , Middle Aged , Prognosis , Survival RateABSTRACT
A gram-negative colonizer of the oral cavity, Fusobacterium nucleatum not only interacts with many pathogens in the oral microbiome but also has the ability to spread to extraoral sites including placenta and amniotic fluid, promoting preterm birth. To date, however, the molecular mechanism of interspecies interactions-termed coaggregation-by F. nucleatum and how coaggregation affects bacterial virulence remain poorly defined. Here, we employed genome-wide transposon mutagenesis to uncover fusobacterial coaggregation factors, revealing the intertwined function of a two-component signal transduction system (TCS), named CarRS, and a lysine metabolic pathway in regulating the critical coaggregation factor RadD. Transcriptome analysis shows that CarR modulates a large regulon including radD and lysine metabolic genes, such as kamA and kamD, the expression of which are highly up-regulated in the ΔcarR mutant. Significantly, the native culture medium of ΔkamA or ΔkamD mutants builds up abundant amounts of free lysine, which blocks fusobacterial coaggregation with streptococci. Our demonstration that lysine-conjugated beads trap RadD from the membrane lysates suggests that lysine utilizes RadD as its receptor to act as a metabolic inhibitor of coaggregation. Lastly, using a mouse model of preterm birth, we show that fusobacterial virulence is significantly attenuated with the ΔkamA and ΔcarR mutants, in contrast to the enhanced virulence phenotype observed upon diminishing RadD (ΔradD or ΔcarS mutant). Evidently, F. nucleatum employs the TCS CarRS and environmental lysine to modulate RadD-mediated interspecies interaction, virulence, and nutrient acquisition to thrive in the adverse environment of oral biofilms and extraoral sites.