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Methods in Molecular Biology (Clifton,... 2021Fusobacterium nucleatum is a human periodontal pathogen that causes opportunistic infections. It has been implicated in preterm birth and has as a pathogen of colorectal...
Fusobacterium nucleatum is a human periodontal pathogen that causes opportunistic infections. It has been implicated in preterm birth and has as a pathogen of colorectal cancer. However, it is a common member of the oral microbiota and can have a symbiotic relationship with its hosts. To date, studies of F. nucleatum have been hindered by a lack of effective genetic tools, and the transformation of F. nucleatum has not been investigated. In this chapter, protocols for the transformation of F. nucleatum strain 12230 using sonoporation are presented. We also include a genetic complementation protocol for a F. nucleatum knockout mutant.
Topics: Colorectal Neoplasms; Fusobacterium Infections; Fusobacterium nucleatum; Humans; Mouth; Transformation, Genetic
PubMed: 32815126
DOI: 10.1007/978-1-0716-0939-2_5 -
International Journal of Molecular... Oct 2019Here, we reviewed emerging evidence on the role of the microbial community in colorectal carcinogenesis. A healthy gut microbiota promotes intestinal homeostasis and can... (Review)
Review
Here, we reviewed emerging evidence on the role of the microbial community in colorectal carcinogenesis. A healthy gut microbiota promotes intestinal homeostasis and can exert anti-cancer effects; however, this microbiota also produces a variety of metabolites that are genotoxic and which can negatively influence epithelial cell behaviour. Disturbances in the normal microbial balance, known as dysbiosis, are frequently observed in colorectal cancer (CRC) patients. Microbial species linked to CRC include certain strains of , and amongst others. Whether these microbes are merely passive dwellers exploiting the tumour environment, or rather, active protagonists in the carcinogenic process is the subject of much research. The incidence of chemically-induced tumours in mice models varies, depending upon the presence or absence of these microorganisms, thus strongly suggesting influences on disease causation. Putative mechanistic explanations differentially link these strains to DNA damage, inflammation, aberrant cell behaviour and immune suppression. In the future, modulating the composition and metabolic activity of this microbial community may have a role in prevention and therapy.
Topics: Animals; Bacteroides; Colorectal Neoplasms; DNA Damage; Fusobacterium; Gastrointestinal Microbiome; Humans; Inflammation; Streptococcus; Tumor Microenvironment
PubMed: 31653078
DOI: 10.3390/ijms20215295 -
Journal of Dental Research Mar 2024Colorectal cancer (CRC) and periodontitis have recently been related due to the higher incidence of CRC in periodontal patients and the involvement of periodontal...
Colorectal cancer (CRC) and periodontitis have recently been related due to the higher incidence of CRC in periodontal patients and the involvement of periodontal pathogens in carcinogenesis, suggesting that leakage from the oral cavity to the gut occurs. However, the magnitude of this pass-through in healthy individuals is controversial, and the effect that periodontitis could play in it is understudied. To evaluate the rate of bacterial leakage from the oral cavity to the gut, we analyzed the microbial composition of saliva, subgingival plaque, and fecal samples in healthy individuals without gastrointestinal disorders, including 20 periodontitis patients and 20 oral healthy controls, using PacBio full-length 16S rRNA gene sequencing. As expected, we observed a higher abundance of periodontal pathogens in the subgingival plaque and saliva of periodontal patients. In contrast, no significant differences were found between the fecal samples of both groups, implying that gut samples from periodontal patients were not enriched in periodontal pathogens. , a biomarker of CRC, was not found in the fecal samples of any participant. Our study does show a small leakage of some oral bacteria (mainly streptococci) to the gut, regardless of periodontal health status. Future studies should test whether other host factors and/or the preexistence of a gut disorder must be present in addition to periodontitis to promote the colonization of the gut by oral pathogens. The absence of periodontal pathogens in feces supports the idea that these bacteria could be used as biomarkers of intestinal disorders, including CRC.
Topics: Humans; RNA, Ribosomal, 16S; Periodontitis; Bacteria; Dental Plaque; Fusobacterium nucleatum
PubMed: 38193290
DOI: 10.1177/00220345231221709 -
Inflammatory Bowel Diseases Jan 2023Ulcerative colitis (UC) may be exacerbated by Fusobacterium nucleatum (Fn) infection. However, the mechanism underlying Fn-mediated progression of UC has yet to be...
BACKGROUND
Ulcerative colitis (UC) may be exacerbated by Fusobacterium nucleatum (Fn) infection. However, the mechanism underlying Fn-mediated progression of UC has yet to be established. Here, we aimed to establish whether and how Fn-derived extracellular vesicles (Fn-EVs) participate in the development of experimental colitis through microRNAs (miRNAs).
METHODS
EVs were isolated and purified by ultracentrifugation from Fn and Escherichia coli culture supernatants. Differentially expressed miRNAs in control intestinal epithelial cells (IECs) and Fn-EV-treated IECs were identified by miRNA sequencing. EVs were cocultured with IECs or administered to CARD3wt/CARD3-/- mice by gavage to assess inflammatory responses to and the mechanism of action of Fn-EVs.
RESULTS
Fn-EVs promoted upregulation of proinflammatory cytokines (interleukin [IL]-1β, IL-6, tumor necrosis factor α), downregulation of anti-inflammatory IL-10 and intercellular tight junction proteins ZO-1 and occludin, and epithelial barrier dysfunction in IECs. Fn-EVs significantly aggravated experimental colitis in mice associated with Fn-EV-mediated downregulation of miR-574-5p expression and autophagy activation. Blockade of autophagy using chloroquine alleviates barrier damage exacerbated by Fn-EVs in vitro and in vivo. Inhibition of the miR-574-5p/CARD3 axis reduced the severity of colitis, epithelial barrier damage, and autophagy activation induced by Fn-EVs.
CONCLUSIONS
Here, we describe a new mechanism by which Fn-EVs mediate experimental colitis severity through miR-574-5p/CARD3-dependent autophagy activation, providing a novel target for UC monitoring and targeted therapy.
Topics: Animals; Mice; Fusobacterium nucleatum; MicroRNAs; Cytokines; Colitis, Ulcerative; Extracellular Vesicles
PubMed: 35998069
DOI: 10.1093/ibd/izac177 -
Cancer Science Sep 2023Intratumor bacteria modify the tumor immune microenvironment and influence outcomes of various tumors. Periodontal pathogen Fusobacterium nucleatum has been detected in...
Intratumor bacteria modify the tumor immune microenvironment and influence outcomes of various tumors. Periodontal pathogen Fusobacterium nucleatum has been detected in pancreatic cancer tissues and is associated with poor prognosis. However, it remains unclear how F. nucleatum affects pancreatic cancer. Here, we compared clinical features with F. nucleatum colonization in pancreatic cancer tissues. F. nucleatum was detected in 15.5% (13/84) of pancreatic cancer patients. The tumor size was significantly larger in the F. nucleatum-positive group than in the negative group. To clarify the biological effect of intratumor F. nucleatum on pancreatic cancer progression, we performed migration/invasion assays and cytokine array analysis of cancer cells cocultured with F. nucleatum. F. nucleatum promoted CXCL1 secretion from pancreatic cancer cells, leading to cancer progression through autocrine signaling. Intratumor F. nucleatum suppressed tumor-infiltrating CD8 T cells by recruiting myeloid-derived suppressor cells (MDSCs) to the tumor in an F. nucleatum-injected subcutaneous pancreatic cancer mouse model, resulting in tumor progression. Furthermore, tumor growth accelerated by F. nucleatum was suppressed by MDSC depletion or cytokine inhibitors. Intratumor F. nucleatum promoted pancreatic cancer progression through autocrine and paracrine mechanisms of the CXCL1-CXCR2 axis. Blockade of the CXCL1-CXCR2 axis may be a novel therapeutic approach for patients with intratumor F. nucleatum-positive pancreatic cancer.
Topics: Animals; Mice; Fusobacterium nucleatum; CD8-Positive T-Lymphocytes; Colorectal Neoplasms; Pancreatic Neoplasms; Cytokines; Tumor Microenvironment
PubMed: 37438965
DOI: 10.1111/cas.15901 -
Journal of Dairy Science Dec 2019Until 2010, our knowledge of the uterine microbiome in cows that developed uterine disease relied almost exclusively on culture-dependent studies and mostly included... (Review)
Review
Until 2010, our knowledge of the uterine microbiome in cows that developed uterine disease relied almost exclusively on culture-dependent studies and mostly included cows with clinical endometritis (i.e., with purulent uterine discharge). Those studies consistently found a strong positive correlation between Trueperella pyogenes and clinical endometritis, whereas other pathogens such as Escherichia coli, Fusobacterium necrophorum, Prevotella melaninogenica, and Bacteroides spp. were also commonly cocultured. In contrast, Streptococcus spp., Staphylococcus spp., and Bacillus spp. were usually isolated from healthy cows. Starting in 2010, culture-independent studies using PCR explored the microbiome of cows with metritis and clinical endometritis, and observed that E. coli was a pioneer pathogen that predisposed cows to infection with F. necrophorum, which was strongly associated with metritis, and to infection with T. pyogenes, which was strongly associated with clinical endometritis. Starting in 2011, culture-independent studies using metagenomic sequencing expanded our knowledge of the uterine microbiome. It has been shown that cows have bacteria in the uterus even before calving, they have an established uterine microbiome within 20 min of calving, and that the microbiome structure is identical between cows that develop metritis and healthy cows until 2 d postpartum, after which the bacterial structure of cows that developed metritis deviates in favor of greater relative abundance of Bacteroidetes and Fusobacteria and lesser relative abundance of Proteobacteria and Tenericutes. The shift in the uterine microbiome in cows that develop metritis is characterized by a loss of heterogeneity and a decrease in bacterial richness. At the genus level, Bacteroides, Porphyromonas, and Fusobacterium have the strongest association with metritis. At the species level, we observed that Bacteroides pyogenes, Porphyromonas levii, and Helcococcus ovis were potential emerging uterine pathogens. Finally, we have shown that the hematogenous route is a viable route of uterine infection with uterine pathogens. Herein, we propose that metritis is associated with a dysbiosis of the uterine microbiota characterized by decreased richness, and an increase in Bacteroidetes and Fusobacteria, particularly Bacteroides, Porphyromonas, and Fusobacterium.
Topics: Animals; Bacteria; Bacteroidetes; Cattle; Cattle Diseases; Dysbiosis; Endometritis; Female; Fusobacteria; Microbiota; Polymerase Chain Reaction; Postpartum Period; Uterine Diseases; Uterus
PubMed: 31587913
DOI: 10.3168/jds.2019-17106 -
Frontiers in Immunology 2022() is originally an oral opportunistic pathogen and accumulating evidence links the presence of with the pathogenicity, development, and prognosis of colorectal cancer... (Review)
Review
() is originally an oral opportunistic pathogen and accumulating evidence links the presence of with the pathogenicity, development, and prognosis of colorectal cancer (CRC). However, only limited preliminary data is available dealing with the role of in other malignancies except for CRC. The present review aims to update and systematize the latest information about the mechanisms of -mediating carcinogenesis, together with the detection rates, clinicopathological, and molecular features in -associated malignancies. Comparing with adjacent non-tumorous tissue, previous studies have shown an overabundance of intratumoural . Although the prognostic role of is still controversial, a higher prevalence of was usually associated with a more advanced tumor stage and a worse overall survival. Preliminary evidence have shown that epithelial-to-mesenchymal transition (EMT) and relevant inflammation and immune response aroused by may be the probable link between infection and the initiation of oral/head and neck cancer. Further studies are needed to elucidate the etiologic role of the specific microbiota and the connection between the extent of periodontitis and carcinogenesis in different tumor types. The mechanisms of how the antibiotics exerts the critical role in the carcinogenesis and antitumor effects in malignancies other than CRC need to be further explored.
Topics: Carcinogenesis; Colorectal Neoplasms; Fusobacterium Infections; Fusobacterium nucleatum; Humans; Prognosis
PubMed: 36059542
DOI: 10.3389/fimmu.2022.968649 -
ACS Nano Jun 2023Intratumoral pathogens can contribute to cancer progression and affect therapeutic response. , a core pathogen of colorectal cancer (CRC), is an important cause of low...
Intratumoral pathogens can contribute to cancer progression and affect therapeutic response. , a core pathogen of colorectal cancer (CRC), is an important cause of low therapeutic efficacy and metastasis. Thus, the modulation of intratumoral pathogens may provide a target for cancer therapy and metastasis inhibition. Herein, we propose an intratumoral -modulating strategy for enhancing the therapeutic efficacy of CRC and inhibiting lung metastasis by designing an antibacterial nanoplatform (Au@BSA-CuPpIX), which produced reactive oxygen species (ROS) under ultrasound and exhibited strong antibacterial activity. Importantly, Au@BSA-CuPpIX reduced the levels of apoptosis-inhibiting proteins by inhibiting intratumoral , thereby enhancing ROS-induced apoptosis. results demonstrated that Au@BSA-CuPpIX effectively eliminated to enhance the therapeutic efficacy of sonodynamic therapy (SDT) for orthotopic CRC and inhibit lung metastasis. Notably, entrapped gold nanoparticles reduced the phototoxicity of metalloporphyrin accumulated in the skin during tumor treatment, preventing severe inflammation and damage to the skin. Therefore, this study proposes a strategy for the elimination of in CRC to enhance the therapeutic effect of SDT, thus providing a promising paradigm for improving cancer treatment with fewer toxic side effects and promoting the clinical translational potential of SDT.
Topics: Humans; Fusobacterium nucleatum; Colorectal Neoplasms; Gold; Reactive Oxygen Species; Metal Nanoparticles
PubMed: 37201179
DOI: 10.1021/acsnano.3c01308 -
Archives of Biochemistry and Biophysics Jul 2023The opportunistic oral pathogen, Fusobacterium nucleatum contains meso-lanthionine as the diaminodicarboxylic acid in the pentapeptide crosslink of the peptidoglycan...
The opportunistic oral pathogen, Fusobacterium nucleatum contains meso-lanthionine as the diaminodicarboxylic acid in the pentapeptide crosslink of the peptidoglycan layer. The diastereomer, l,l-lanthionine is formed by lanthionine synthase, a PLP-dependent enzyme that catalyzes the β-replacement of l-cysteine with a second equivalent of l-cysteine. In this study, we explored possible enzymatic mechanisms for the formation of meso-lanthionine. Our inhibition studies with lanthionine synthase, described herein, revealed that meso-diaminopimelate, a bioisostere of meso-lanthionine, is a more potent inhibitor of lanthionine synthase compared to the diastereomer, l,l-diaminopimelate. These results suggested that lanthionine synthase could also form meso-lanthionine by the β-replacement of l-cysteine with d-cysteine. Through steady-state and pre-steady state kinetic analysis, we confirm that d-cysteine reacts with the ⍺-aminoacylate intermediate with a k that was 2-3-fold faster and K value that was 2-3fold lower compared to l-cysteine. However, given that intracellular levels of d-cysteine levels are assumed to be significantly lower than that of l-cysteine, we also determined if the gene product, FN1732, with low sequence identity to diaminopimelate epimerase could convert l,l-lanthionine to meso-lanthionine. Using diaminopimelate dehydrogenase in a coupled spectrophotometric assay, we show that FN1732 can convert l,l-lanthionine to meso-lanthionine with a k of 0.07 ± 0.001 s and a K of 1.9 ± 0.1 mM. In summary, our results provide two possible enzymatic mechanisms for the biosynthesis of meso-lanthionine in F. nucleatum.
Topics: Fusobacterium nucleatum; Cysteine; Kinetics; Sulfides
PubMed: 37329940
DOI: 10.1016/j.abb.2023.109666 -
Oncology Letters May 2024Liver metastasis is a major cause of mortality in patients with advanced stages of colorectal cancer (CRC). The gut microbiota has been demonstrated to influence the...
Liver metastasis is a major cause of mortality in patients with advanced stages of colorectal cancer (CRC). The gut microbiota has been demonstrated to influence the progression of liver diseases, potentially providing novel perspectives for diagnosis, treatment and research. However, the gut microbial characteristics in CRC with liver metastasis (LM) and with no liver metastasis (NLM) have not yet been fully established. In the present study, high-throughput 16S RNA sequencing technology was employed, in order to examine the gut microbial richness and composition in patients with CRC with LM or NLM. A discovery cohort (cohort 2; LM=18; NLM=36) and a validation cohort (cohort 3; LM=13; NLM=41) were established using fresh feces. In addition, primary carcinoma tissue samples were also analyzed (LM=8 and NLM=10) as a supplementary discovery cohort (cohort 1). The findings of the present study indicated that the intestinal microbiota richness and diversity were increased in the LM group as compared to the NLM group. A significant difference was observed in species composition between the LM and NLM group. In the two discovery cohorts with two different samples, the dominant phyla were consistent, but varied at lower taxonomic levels. Phylum Fusobacteria presented consistent and significant enrichment in LM group in both discovery cohorts. Furthermore, with the application of a random forest model and receiver operator characteristic curve analysis, Fusobacteria was identified as a potential biomarker for LM. Moreover, Fusobacteria was also a poor prognosis factor for survival. Importantly, the findings were reconfirmed in the validation cohort. On the whole, the findings of the present study demonstrated that CRC with LM and NLM exhibit distinct gut microbiota characteristics. Fusobacteria detection thus has potential for use in predicting LM and a poor prognosis of patients with CRC.
PubMed: 38596264
DOI: 10.3892/ol.2024.14368