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Escherichia coli isolates from patients with inflammatory bowel disease: ExPEC virulence- and colicin-determinants are more frequent compared to healthy controls. Int J Med Microbiol 2018; 308:498-504. [PMID: 29735381 DOI: 10.1016/j.ijmm.2018.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 04/04/2018] [Accepted: 04/30/2018] [Indexed: 12/12/2022] Open
Abstract
A set of 178 Escherichia coli isolates taken from patients with inflammatory bowel disease (IBD) was analyzed for bacteriocin production and tested for the prevalence of 30 bacteriocin and 22 virulence factor determinants. Additionally, E. coli phylogenetic groups were also determined. Pulsed-field gel electrophoresis (PFGE) was used for exclusion of clonal character of isolates. Results were compared to data from a previously published analysis of 1283 fecal commensal E. coli isolates. The frequency of bacteriocinogenic isolates (66.9%) was significantly higher in IBD E. coli compared to fecal commensal E. coli isolates (54.2%, p < 0.01). In the group of IBD E. coli isolates, a higher prevalence of determinants for group B colicins (i.e., colicins B, D, Ia, Ib, M, and 5/10) (p < 0.01), including a higher prevalence of the colicin B determinant (p < 0.01) was found. Virulence factor determinants encoding fimbriae (fimA, 91.0%; pap, 27.5%), cytotoxic necrotizing factor (cnf1, 11.2%), aerobactin synthesis (aer, 43.3%), and the locus associated with invasivity (ial, 9.0%) were more prevalent in IBD E. coli (p < 0.05 for all five determinants). E. coli isolates from IBD mucosal biopsies were more frequently bacteriocinogenic (84.6%, p < 0.01) compared to fecal IBD isolates and fecal commensal E. coli. PFGE analysis revealed clusters specific for IBD E. coli isolates (n = 11), for fecal isolates (n = 13), and clusters containing both IBD and fecal isolates (n = 10). ExPEC (Extraintestinal Pathogenic E. coli) virulence and colicin determinants appear to be important characteristics of IBD E. coli isolates, especially the E. coli isolates obtained directly from biopsy samples.
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Lucke A, Böhm J, Zebeli Q, Metzler-Zebeli BU. Dietary Deoxynivalenol Contamination and Oral Lipopolysaccharide Challenge Alters the Cecal Microbiota of Broiler Chickens. Front Microbiol 2018; 9:804. [PMID: 29922239 PMCID: PMC5996912 DOI: 10.3389/fmicb.2018.00804] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/10/2018] [Indexed: 12/18/2022] Open
Abstract
Dietary deoxynivalenol (DON) impairs the intestinal functions and performance in broiler chickens, whereas little is known about the effect of DON on the gastrointestinal microbiota. This study evaluated the impact of graded levels of dietary DON contamination on the cecal bacterial microbiota, their predicted metabolic abilities and short-chain fatty acid (SCFA) profiles in chickens. In using a single oral lipopolysaccharide (LPS) challenge we further assessed whether an additional intestinal stressor would potentiate DON-related effects on the cecal microbiota. Eighty 1-day-old chicks were fed diets with increasing DON concentrations (0, 2.5, 5, and 10 mg DON per kg diet) for 5 weeks and were sampled after half of the chickens received an oral LPS challenge (1 mg LPS/kg bodyweight) 1 day before sampling. The bacterial composition was investigated by Illumina MiSeq sequencing of the V3–5 region of the 16S rRNA gene. DON-feeding decreased (p < 0.05) the cecal species richness (Chao1) and evenness (Shannon) compared to the non-contaminated diet. The phyla Firmicutes and Proteobacteria tended to linearly increase and decrease with increasing DON-concentrations, respectively. Within the Firmicutes, DON decreased the relative abundance of Oscillospira, Clostridiaceae genus, Clostridium, and Ruminococcaceae genus 2 (p < 0.05), whereas it increased Clostridiales genus 2 (p < 0.05). Moreover, increasing DON levels linearly decreased a high-abundance Enterobacteriaceae genus and an Escherichia/Shigella-OTU (p < 0.05). Changes in the bacterial composition and their imputed metagenomic capabilities may be explained by DON-related changes in host physiology and cecal nutrient availability. The oral LPS challenge only decreased the abundance of an unassigned Clostridiales genus 2 (p = 0.03). Increasing dietary concentrations of DON quadratically increased the cecal total SCFA and butyrate concentration (p < 0.05), whereas a DON × LPS interaction indicated that LPS mainly increased cecal total SCFA, butyrate, and acetate concentrations in chickens fed the diets that were not contaminated with DON. The present findings showed that even the lowest level of dietary DON contamination had modulatory effects on chicken's cecal bacterial microbiota composition and diversity, whereas the additional oral challenge with LPS did not potentiate DON effects on the cecal bacterial composition.
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Affiliation(s)
- Annegret Lucke
- Department for Farm Animals and Veterinary Public Health, Institute of Animal Nutrition and Functional Plant Compounds, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Josef Böhm
- Department for Farm Animals and Veterinary Public Health, Institute of Animal Nutrition and Functional Plant Compounds, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Qendrim Zebeli
- Department for Farm Animals and Veterinary Public Health, Institute of Animal Nutrition and Functional Plant Compounds, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Barbara U Metzler-Zebeli
- Department for Farm Animals and Veterinary Public Health, Institute of Animal Nutrition and Functional Plant Compounds, University of Veterinary Medicine Vienna, Vienna, Austria
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Sina C, Kemper C, Derer S. The intestinal complement system in inflammatory bowel disease: Shaping intestinal barrier function. Semin Immunol 2018; 37:66-73. [PMID: 29486961 DOI: 10.1016/j.smim.2018.02.008] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/05/2018] [Accepted: 02/18/2018] [Indexed: 12/18/2022]
Abstract
The complement system is part of innate sensor and effector systems such as the Toll-like receptors (TLRs). It recognizes and quickly systemically and/or locally respond to microbial-associated molecular patterns (MAMPs) with a tailored defense reaction. MAMP recognition by intestinal epithelial cells (IECs) and appropriate immune responses are of major importance for the maintenance of intestinal barrier function. Enterocytes highly express various complement components that are suggested to be pivotal for proper IEC function. Appropriate activation of the intestinal complement system seems to play an important role in the resolution of chronic intestinal inflammation, while over-activation and/or dysregulation may worsen intestinal inflammation. Mice deficient for single complement components suffer from enhanced intestinal inflammation mimicking the phenotype of patients with chronic inflammatory bowel disease (IBD) such as Crohn's disease (CD) or ulcerative colitis (UC). However, the mechanisms leading to complement expression in IECs seem to differ markedly between UC and CD patients. Hence, how IECs, intestinal bacteria and epithelial cell expressed complement components interact in the course of IBD still remains to be mostly elucidated to define potential unique patterns contributing to the distinct subtypes of intestinal inflammation observed in CD and UC.
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Affiliation(s)
- Christian Sina
- Institute of Nutritional Medicine, Molecular Gastroenterology, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany; 1st Department of Medicine, Section of Nutritional Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Claudia Kemper
- Institute for Systemic Inflammation Research, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany; Division of Transplant Immunology and Mucosal Biology, Medical Research Council Centre for Transplantation, King's College London, Guy's Hospital, Great Maze Pond, London SE1 9RT, UK; Laboratory of Molecular Immunology and the Immunology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stefanie Derer
- Institute of Nutritional Medicine, Molecular Gastroenterology, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.
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Bishehsari F, Engen PA, Preite NZ, Tuncil YE, Naqib A, Shaikh M, Rossi M, Wilber S, Green SJ, Hamaker BR, Khazaie K, Voigt RM, Forsyth CB, Keshavarzian A. Dietary Fiber Treatment Corrects the Composition of Gut Microbiota, Promotes SCFA Production, and Suppresses Colon Carcinogenesis. Genes (Basel) 2018; 9:genes9020102. [PMID: 29462896 PMCID: PMC5852598 DOI: 10.3390/genes9020102] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/29/2018] [Accepted: 02/13/2018] [Indexed: 12/26/2022] Open
Abstract
Epidemiological studies propose a protective role for dietary fiber in colon cancer (CRC). One possible mechanism of fiber is its fermentation property in the gut and ability to change microbiota composition and function. Here, we investigate the role of a dietary fiber mixture in polyposis and elucidate potential mechanisms using TS4Cre × cAPCl°x468 mice. Stool microbiota profiling was performed, while functional prediction was done using PICRUSt. Stool short-chain fatty acid (SCFA) metabolites were measured. Histone acetylation and expression of SCFA butyrate receptor were assessed. We found that SCFA-producing bacteria were lower in the polyposis mice, suggesting a decline in the fermentation product of dietary fibers with polyposis. Next, a high fiber diet was given to polyposis mice, which significantly increased SCFA-producing bacteria as well as SCFA levels. This was associated with an increase in SCFA butyrate receptor and a significant decrease in polyposis. In conclusion, we found polyposis to be associated with dysbiotic microbiota characterized by a decline in SCFA-producing bacteria, which was targetable by high fiber treatment, leading to an increase in SCFA levels and amelioration of polyposis. The prebiotic activity of fiber, promoting beneficial bacteria, could be the key mechanism for the protective effects of fiber on colon carcinogenesis. SCFA-promoting fermentable fibers are a promising dietary intervention to prevent CRC.
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Affiliation(s)
- Faraz Bishehsari
- Department of Internal Medicine, Division of Gastroenterology, Rush University Medical Center, Chicago, IL USA.
| | - Phillip A Engen
- Department of Internal Medicine, Division of Gastroenterology, Rush University Medical Center, Chicago, IL USA.
| | - Nailliw Z Preite
- Department of Internal Medicine, Division of Gastroenterology, Rush University Medical Center, Chicago, IL USA.
| | - Yunus E Tuncil
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, IN USA.
| | - Ankur Naqib
- DNA Services Facility, Research Resources Center, University of Illinois at Chicago, Chicago, IL USA.
| | - Maliha Shaikh
- Department of Internal Medicine, Division of Gastroenterology, Rush University Medical Center, Chicago, IL USA.
| | - Marco Rossi
- Department of Internal Medicine, Division of Gastroenterology, Rush University Medical Center, Chicago, IL USA.
| | - Sherry Wilber
- Department of Internal Medicine, Division of Gastroenterology, Rush University Medical Center, Chicago, IL USA.
| | - Stefan J Green
- DNA Services Facility, Research Resources Center, University of Illinois at Chicago, Chicago, IL USA.
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL USA.
| | - Bruce R Hamaker
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, IN USA.
| | - Khashayarsha Khazaie
- Department of Immunology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN 55905, USA.
| | - Robin M Voigt
- Department of Internal Medicine, Division of Gastroenterology, Rush University Medical Center, Chicago, IL USA.
| | - Christopher B Forsyth
- Department of Internal Medicine, Division of Gastroenterology, Rush University Medical Center, Chicago, IL USA.
| | - Ali Keshavarzian
- Department of Internal Medicine, Division of Gastroenterology, Rush University Medical Center, Chicago, IL USA.
- Department of Physiology, Rush University Medical Center, Chicago, IL USA.
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht Netherlands.
- Department of Pharmacology, Rush University Medical Center, Chicago, IL USA.
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Abstract
Acute-on-chronic liver failure (ACLF) is characterized by organ failure mediated by acute decompensation of cirrhosis. Recent studies have highlighted the importance of the gut-liver axis (GLS) and its association with ACLF pathogenesis. In this review, we discuss the mechanisms related to the alteration of the GLA and their involvement in ACLF pathogenesis and suggest some possible therapeutic options that could modulate the GLA dysfunction. This knowledge may provide information useful for the design of therapeutic strategies for gut dysbiosis and its complications in ACLF.
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56
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Choi JG, Kim N, Ju IG, Eo H, Lim SM, Jang SE, Kim DH, Oh MS. Oral administration of Proteus mirabilis damages dopaminergic neurons and motor functions in mice. Sci Rep 2018; 8:1275. [PMID: 29352191 PMCID: PMC5775305 DOI: 10.1038/s41598-018-19646-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/15/2017] [Indexed: 12/16/2022] Open
Abstract
Recently, studies on the relationship between gut dysbiosis and Parkinson's disease (PD) have increased, but whether a specific gut bacterium may cause PD remains unexplored. Here, we report, for the first time, that a specific gut bacterium directly induces PD symptoms and dopaminergic neuronal damage in the mouse brain. We found that the number of Enterobacteriaceae, particularly Proteus mirabilis, markedly and commonly increased in PD mouse models. Administration of P. mirabilis isolated from PD mice significantly induced motor deficits, selectively caused dopaminergic neuronal damage and inflammation in substantia nigra and striatum, and stimulated α-synuclein aggregation in the brain as well as in the colon. We found that lipopolysaccharides, a virulence factor of P. mirabilis, may be associated in these pathological changes via gut leakage and inflammatory actions. Our results suggest a role of P. mirabilis on PD pathogenesis in the brain.
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Affiliation(s)
- Jin Gyu Choi
- Department of Life and Nanopharmaceutical Sciences, Graduate School, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Namkwon Kim
- Department of Life and Nanopharmaceutical Sciences, Graduate School, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - In Gyoung Ju
- Department of Life and Nanopharmaceutical Sciences, Graduate School, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Hyeyoon Eo
- Department of Life and Nanopharmaceutical Sciences, Graduate School, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Su-Min Lim
- Department of Life and Nanopharmaceutical Sciences, Graduate School, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Se-Eun Jang
- Department of Life and Nanopharmaceutical Sciences, Graduate School, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Dong-Hyun Kim
- Department of Life and Nanopharmaceutical Sciences, Graduate School, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Myung Sook Oh
- Department of Life and Nanopharmaceutical Sciences, Graduate School, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
- Department of Oriental Pharmaceutical Science, College of Pharmacy and Kyung Hee East-West Pharmaceutical Research Institute, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
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57
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Sagnelli D, Chessa S, Mandalari G, Di Martino M, Sorndech W, Mamone G, Vincze E, Buillon G, Nielsen DS, Wiese M, Blennow A, Hebelstrup KH. Low glycaemic index foods from wild barley and amylose-only barley lines. J Funct Foods 2018. [DOI: 10.1016/j.jff.2017.11.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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58
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Structural basis for the regulation of β-glucuronidase expression by human gut Enterobacteriaceae. Proc Natl Acad Sci U S A 2017; 115:E152-E161. [PMID: 29269393 DOI: 10.1073/pnas.1716241115] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The gut microbiota harbor diverse β-glucuronidase (GUS) enzymes that liberate glucuronic acid (GlcA) sugars from small-molecule conjugates and complex carbohydrates. However, only the Enterobacteriaceae family of human gut-associated Proteobacteria maintain a GUS operon under the transcriptional control of a glucuronide repressor, GusR. Despite its potential importance in Escherichia, Salmonella, Klebsiella, Shigella, and Yersinia opportunistic pathogens, the structure of GusR has not been examined. Here, we explore the molecular basis for GusR-mediated regulation of GUS expression in response to small-molecule glucuronides. Presented are 2.1-Å-resolution crystal structures of GusRs from Escherichia coli and Salmonella enterica in complexes with a glucuronide ligand. The GusR-specific DNA operator site in the regulatory region of the E. coli GUS operon is identified, and structure-guided GusR mutants pinpoint the residues essential for DNA binding and glucuronide recognition. Interestingly, the endobiotic estradiol-17-glucuronide and the xenobiotic indomethacin-acyl-glucuronide are found to exhibit markedly differential binding to these GusR orthologs. Using structure-guided mutations, we are able to transfer E. coli GusR's preferential DNA and glucuronide binding affinity to S. enterica GusR. Structures of putative GusR orthologs from GUS-encoding Firmicutes species also reveal functionally unique features of the Enterobacteriaceae GusRs. Finally, dominant-negative GusR variants are validated in cell-based studies. These data provide a molecular framework toward understanding the control of glucuronide utilization by opportunistic pathogens in the human gut.
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Sarshar M, Scribano D, Marazzato M, Ambrosi C, Aprea MR, Aleandri M, Pronio A, Longhi C, Nicoletti M, Zagaglia C, Palamara AT, Conte MP. Genetic diversity, phylogroup distribution and virulence gene profile of pks positive Escherichia coli colonizing human intestinal polyps. Microb Pathog 2017; 112:274-278. [PMID: 28987619 DOI: 10.1016/j.micpath.2017.10.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/05/2017] [Accepted: 10/04/2017] [Indexed: 02/07/2023]
Abstract
Some Escherichia coli strains of phylogroup B2 harbor a (pks) pathogenicity island that encodes a polyketide-peptide genotoxin called colibactin. It causes DNA double-strand breaks and megalocytosis in eukaryotic cells and it may contribute to cancer development. Study of bacterial community that colonizes the adenomatous polyp lesion, defined as precancerous lesions, could be helpful to assess if such pathogenic bacteria possess a role in the polyp progression to cancer. In this cross-sectional study, a total of 1500 E. coli isolates were obtained from biopsies of patients presenting adenomatous colon polyps, the normal tissues adjacent to the polyp lesion and patients presenting normal mucosa. pks island frequency, phylogenetic grouping, fingerprint genotyping, and virulence gene features of pks positive (pks+) E. coli isolates were performed. We found pks+E. coli strongly colonize two patients presenting polypoid lesions and none were identified in patients presenting normal mucosa. Predominant phylogroups among pks+E. coli isolates were B2, followed by D. Clustering based on fragment profiles of composite analysis, typed the pks+ isolates into 5 major clusters (I-V) and 17 sub-clusters, demonstrating a high level of genetic diversity among them. The most prevalent virulence genes were fimH and fyuA (100%), followed by vat (92%), hra and papA (69%), ibeA (28%), and hlyA (25%). Our results revealed that pks+E. coli can colonize the precancerous lesions, with a high distribution in both the polyp lesions and in normal tissues adjacent to the lesion. The high differences in fingerprinting patterns obtained indicate that pks+E. coli strains were genetically diverse, possibly allowing them to more easily adapt to environmental variations.
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Affiliation(s)
- Meysam Sarshar
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Laboratory Affiliated to Institute Pasteur Italia-Fondazione Cenci Bolognetti, Rome, Italy; Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
| | - Daniela Scribano
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy; Department of Medical, Oral and Biotechnological Sciences, University "G. D'Annunzio" of Chieti, Chieti, Italy.
| | - Massimiliano Marazzato
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Cecilia Ambrosi
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Maria Rita Aprea
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Marta Aleandri
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Annamaria Pronio
- Department of General Surgery, "P. Stefanini", Sapienza University of Rome, Rome, Italy
| | - Catia Longhi
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Mauro Nicoletti
- Department of Medical, Oral and Biotechnological Sciences, University "G. D'Annunzio" of Chieti, Chieti, Italy
| | - Carlo Zagaglia
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Anna Teresa Palamara
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Laboratory Affiliated to Institute Pasteur Italia-Fondazione Cenci Bolognetti, Rome, Italy; San Raffaele Pisana IRCCS, Telematic University, Rome, Italy
| | - Maria Pia Conte
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
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Ilinskaya ON, Ulyanova VV, Yarullina DR, Gataullin IG. Secretome of Intestinal Bacilli: A Natural Guard against Pathologies. Front Microbiol 2017; 8:1666. [PMID: 28919884 PMCID: PMC5586196 DOI: 10.3389/fmicb.2017.01666] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 08/17/2017] [Indexed: 12/12/2022] Open
Abstract
Current studies of human gut microbiome usually do not consider the special functional role of transient microbiota, although some of its members remain in the host for a long time and produce broad spectrum of biologically active substances. Getting into the gastrointestinal tract (GIT) with food, water and probiotic preparations, two representatives of Bacilli class, genera Bacillus and Lactobacillus, colonize epithelium blurring the boundaries between resident and transient microbiota. Despite their minor proportion in the microbiome composition, these bacteria can significantly affect both the intestinal microbiota and the entire body thanks to a wide range of secreted compounds. Recently, insufficiency and limitations of pure genome-based analysis of gut microbiota became known. Thus, the need for intense functional studies is evident. This review aims to characterize the Bacillus and Lactobacillus in GIT, as well as the functional roles of the components released by these members of microbial intestinal community. Complex of their secreted compounds is referred by us as the "bacillary secretome." The composition of the bacillary secretome, its biological effects in GIT and role in counteraction to infectious diseases and oncological pathologies in human organism is the subject of the review.
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Affiliation(s)
| | - Vera V. Ulyanova
- Department of Microbiology, Kazan Federal UniversityKazan, Russia
| | | | - Ilgiz G. Gataullin
- Department of Surgery and Oncology, Regional Clinical Cancer CenterKazan, Russia
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Abstract
肠道菌群(gut microbiota, GM)承担人体诸多生理功能, 因而被视为人体"器官", GM紊乱与代谢性疾病、免疫性疾病以及部分恶性肿瘤的发病密切相关, 机会致病菌的感染可以导致众多疾病的发生. 针对GM紊乱, 可采取粪菌移植(fecal microbiota transplantation, FMT)、补充益生菌、抗生素等治疗途径. 目前FMT在治疗难辨索状芽孢杆菌感染等疾病中已取得了满意的疗效. 随着肠道微生态研究深入, 基于GM的药物开发和临床治疗有望成为疾病防控的新方向.
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Hypotheses on the Potential of Rice Bran Intake to Prevent Gastrointestinal Cancer through the Modulation of Oxidative Stress. Int J Mol Sci 2017; 18:ijms18071352. [PMID: 28672811 PMCID: PMC5535845 DOI: 10.3390/ijms18071352] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 06/14/2017] [Accepted: 06/20/2017] [Indexed: 12/15/2022] Open
Abstract
Previous studies have suggested the potential involvement of oxidative stress in gastrointestinal cancers. In light of this, research efforts have been focused on the potential of dietary antioxidant intake to prevent gastrointestinal cancer through the modulation of oxidative stress. Rice bran, a by-product of rice milling, has been shown to contain an abundance of phytochemicals, which are dietary antioxidants. To date, a number of studies have shown the antioxidative effect of rice bran intake, and some demonstrated that such an effect may contribute to gastrointestinal cancer prevention, largely through the antioxidative properties of rice bran phytochemicals. In addition, these phytochemicals were shown to provide protection against cancer through mechanisms linked to oxidative stress, including β-catenin-mediated cell proliferation and inflammation. The present article provides an overview of current evidence for the antioxidative properties of rice bran and its phytochemicals, and for the potential of such properties in cancer prevention through the oxidative-stress-linked mechanisms mentioned above. The article also highlights the need for an evaluation of the effectiveness of rice bran dietary interventions among cancer survivors in ameliorating oxidative stress and reducing the level of gastrointestinal cancer biomarkers, thereby establishing the potential of such interventions among these individuals in the prevention of cancer recurrence.
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63
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Gabrielli MG, Tomassoni D. Starch-enriched diet modulates the glucidic profile in the rat colonic mucosa. Eur J Nutr 2017; 57:1109-1121. [PMID: 28393287 DOI: 10.1007/s00394-017-1393-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 02/02/2017] [Indexed: 01/10/2023]
Abstract
PURPOSE The protective function of the intestinal mucosa largely depends on carbohydrate moieties that as a part of glycoproteins and glycolipids form the epithelial glycocalyx or are secreted as mucins. Modifications of their expression can be induced by an altered intestinal microenvironment and have been associated with inflammatory disorders and colorectal cancer. Given the influence of dietary factors on the gut ecosystem, here we have investigated whether a long term feeding on a starch-rich diet can modulate the glucidic profile in the colonic mucosa of rats. METHODS Animals were divided into two groups and maintained for 9 months at different diets: one group was fed a standard diet, the second was fed a starch-enriched diet. Samples of colonic mucosa, divided in proximal and distal portions, were processed for microscopic analysis. Conventional stainings and lectin histochemistry were applied to identify acidic glycoconjugates and specific sugar residues in oligosaccharide chains, respectively. Some lectins were applied on adjacent sections after sialidase/fucosidase digestion, deacetylation, and oxidation to characterize either terminal dimers or sialic acid acetylation. RESULTS An increase in sulfomucins was found to be associated with the starch-enriched diet that affected also the expression of several sugar residues as well as fucosylated and sialylated sequences in both proximal and distal colon. CONCLUSIONS Although the mechanisms leading to such a modulation are at present unknown, either an altered intestinal microbiota or a dysregulation of glycosylation patterns might be responsible for the types and distribution of changes in the glucidic profile here observed.
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Affiliation(s)
- Maria Gabriella Gabrielli
- School of Biosciences and Veterinary Medicine, University of Camerino, Via Gentile III da Varano, I, Camerino, 62032, Macerata, Italy.
| | - Daniele Tomassoni
- School of Biosciences and Veterinary Medicine, University of Camerino, Via Gentile III da Varano, I, Camerino, 62032, Macerata, Italy
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Triff K, McLean MW, Konganti K, Pang J, Callaway E, Zhou B, Ivanov I, Chapkin RS. Assessment of histone tail modifications and transcriptional profiling during colon cancer progression reveals a global decrease in H3K4me3 activity. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1392-1402. [PMID: 28315775 DOI: 10.1016/j.bbadis.2017.03.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 02/08/2017] [Accepted: 03/14/2017] [Indexed: 01/07/2023]
Abstract
During colon cancer, epigenetic alterations contribute to the dysregulation of major cellular functions and signaling pathways. Modifications in chromatin signatures such as H3K4me3 and H3K9ac, which are associated with transcriptionally active genes, can lead to genomic instability and perturb the expression of gene sets associated with oncogenic processes. In order to further elucidate early pre-tumorigenic epigenetic molecular events driving CRC, we integrated diverse, genome-wide, epigenetic inputs (by high throughput sequencing of RNA, H3K4me3, and H3K9ac) and compared differentially expressed transcripts (DE) and enriched regions (DER) in an in-vivo rat colon cancer progression model. Carcinogen (AOM) effects were detected genome-wide at the RNA (116 DE genes), K9ac (49 DERs including 24 genes) and K4me3 (7678 DERs including 3792 genes) level. RNA-seq differential expression and pathway analysis indicated that interferon-associated innate immune responses were impacted by AOM exposure. Despite extensive associations between K4me3 DERs and colon tumorigenesis (1210 genes were linked to colorectal carcinoma) including FOXO3, GNAI2, H2AFX, MSH2, NR3C1, PDCD4 and VEGFA, these changes were not reflected at the RNA gene expression level during early cancer progression. Collectively, our results indicate that carcinogen-induced changes in gene K4me3 DERs are harbingers of future transcriptional events, which drive malignant transformation of the colon.
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Affiliation(s)
- Karen Triff
- Department of Nutrition and Food Science and Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX 77843, USA; Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - Mathew W McLean
- Department of Statistics in Texas A&M University, College Station, 77843, TX, USA
| | - Kranti Konganti
- Texas A&M Institute for Genome Sciences and Society, Texas A&M University, College Station, TX 77843, USA
| | - Jiahui Pang
- Department of Nutrition and Food Science and Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX 77843, USA
| | - Evelyn Callaway
- Department of Nutrition and Food Science and Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX 77843, USA
| | - Beiyan Zhou
- Veterinary Physiology & Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - Ivan Ivanov
- Department of Nutrition and Food Science and Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX 77843, USA; Department of Statistics in Texas A&M University, College Station, 77843, TX, USA; Veterinary Physiology & Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - Robert S Chapkin
- Department of Nutrition and Food Science and Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX 77843, USA.
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65
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Pope JL, Tomkovich S, Yang Y, Jobin C. Microbiota as a mediator of cancer progression and therapy. Transl Res 2017; 179:139-154. [PMID: 27554797 PMCID: PMC5674984 DOI: 10.1016/j.trsl.2016.07.021] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 07/18/2016] [Accepted: 07/20/2016] [Indexed: 12/19/2022]
Abstract
Complex and intricate circuitries regulate cellular proliferation, survival, and growth, and alterations of this network through genetic and epigenetic events result in aberrant cellular behaviors, often leading to carcinogenesis. Although specific germline mutations have been recognized as cancer inducers, the vast majority of neoplastic changes in humans occur through environmental exposure, lifestyle, and diet. An emerging concept in cancer biology implicates the microbiota as a powerful environmental factor modulating the carcinogenic process. For example, the intestinal microbiota influences cancer development or therapeutic responses through specific activities (immune responses, metabolites, microbial structures, and toxins). The numerous effects of microbiota on carcinogenesis, ranging from promoting, preventing, or even influencing therapeutic outcomes, highlight the complex relationship between the biota and the host. In this review, we discuss the latest findings on this complex microbial interaction with the host and highlight potential mechanisms by which the microbiota mediates such a wide impact on carcinogenesis.
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Affiliation(s)
- Jillian L Pope
- Department of Medicine, University of Florida, Gainesville, Fla
| | - Sarah Tomkovich
- Department of Medicine, University of Florida, Gainesville, Fla; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Ye Yang
- Department of Medicine, University of Florida, Gainesville, Fla
| | - Christian Jobin
- Department of Medicine, University of Florida, Gainesville, Fla; Department of Infectious Diseases and Pathology, University of Florida, Gainesville, Fla.
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66
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Abstract
The primate gastrointestinal tract is home to trillions of bacteria, whose composition is associated with numerous metabolic, autoimmune, and infectious human diseases. Although there is increasing evidence that modern and Westernized societies are associated with dramatic loss of natural human gut microbiome diversity, the causes and consequences of such loss are challenging to study. Here we use nonhuman primates (NHPs) as a model system for studying the effects of emigration and lifestyle disruption on the human gut microbiome. Using 16S rRNA gene sequencing in two model NHP species, we show that although different primate species have distinctive signature microbiota in the wild, in captivity they lose their native microbes and become colonized with Prevotella and Bacteroides, the dominant genera in the modern human gut microbiome. We confirm that captive individuals from eight other NHP species in a different zoo show the same pattern of convergence, and that semicaptive primates housed in a sanctuary represent an intermediate microbiome state between wild and captive. Using deep shotgun sequencing, chemical dietary analysis, and chloroplast relative abundance, we show that decreasing dietary fiber and plant content are associated with the captive primate microbiome. Finally, in a meta-analysis including published human data, we show that captivity has a parallel effect on the NHP gut microbiome to that of Westernization in humans. These results demonstrate that captivity and lifestyle disruption cause primates to lose native microbiota and converge along an axis toward the modern human microbiome.
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67
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Barrett KE. Endogenous and exogenous control of gastrointestinal epithelial function: building on the legacy of Bayliss and Starling. J Physiol 2016; 595:423-432. [PMID: 27284010 DOI: 10.1113/jp272227] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 04/12/2016] [Indexed: 12/21/2022] Open
Abstract
Transport of fluid and electrolytes in the intestine allows for appropriate adjustments in luminal fluidity while reclaiming water used in digesting and absorbing a meal, and is closely regulated. This article discusses various endogenous and exogenous mechanisms whereby transport is controlled in the gut, placing these in the context of the ideas about the neurohumoral control of alimentary physiology that were promulgated by William Bayliss and Ernest Starling. The article considers three themes. First, mechanisms that intrinsically regulate chloride secretion, centred on the epidermal growth factor receptor (EGFr), are discussed. These may be important in ensuring that excessive chloride secretion, with the accompanying loss of fluid, is not normally stimulated by intestinal distension as the meal passes through the gastrointestinal tract. Second, mechanisms whereby probiotic microorganisms can impart beneficial effects on the gut are described, with a focus on targets at the level of the epithelium. These findings imply that the commensal microbiota exert important influences on the epithelium in health and disease. Finally, mechanisms that lead to diarrhoea in patients infected with an invasive pathogen, Salmonella, are considered, based on recent studies in a novel mouse model. Diarrhoea is most likely attributable to reduced expression of absorptive transporters and may not require the influx of neutrophils that accompanies infection. Overall, the goal of the article is to highlight the many ways in which critical functions of the intestinal epithelium are regulated under physiological and pathophysiological conditions, and to suggest possible targets for new therapies for digestive disease states.
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Affiliation(s)
- Kim E Barrett
- Department of Medicine and Biomedical Sciences Ph.D. Program, School of Medicine, University of California, La Jolla, San Diego, CA, USA
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68
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Kumar A, Thotakura PL, Tiwary BK, Krishna R. Target identification in Fusobacterium nucleatum by subtractive genomics approach and enrichment analysis of host-pathogen protein-protein interactions. BMC Microbiol 2016; 16:84. [PMID: 27176600 PMCID: PMC4866016 DOI: 10.1186/s12866-016-0700-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 05/06/2016] [Indexed: 02/07/2023] Open
Abstract
Background Fusobacterium nucleatum, a well studied bacterium in periodontal diseases, appendicitis, gingivitis, osteomyelitis and pregnancy complications has recently gained attention due to its association with colorectal cancer (CRC) progression. Treatment with berberine was shown to reverse F. nucleatum-induced CRC progression in mice by balancing the growth of opportunistic pathogens in tumor microenvironment. Intestinal microbiota imbalance and the infections caused by F. nucleatum might be regulated by therapeutic intervention. Hence, we aimed to predict drug target proteins in F. nucleatum, through subtractive genomics approach and host-pathogen protein-protein interactions (HP-PPIs). We also carried out enrichment analysis of host interacting partners to hypothesize the possible mechanisms involved in CRC progression due to F. nucleatum. Results In subtractive genomics approach, the essential, virulence and resistance related proteins were retrieved from RefSeq proteome of F. nucleatum by searching against Database of Essential Genes (DEG), Virulence Factor Database (VFDB) and Antibiotic Resistance Gene-ANNOTation (ARG-ANNOT) tool respectively. A subsequent hierarchical screening to identify non-human homologous, metabolic pathway-independent/pathway-specific and druggable proteins resulted in eight pathway-independent and 27 pathway-specific druggable targets. Co-aggregation of F. nucleatum with host induces proinflammatory gene expression thereby potentiates tumorigenesis. Hence, proteins from IBDsite, a database for inflammatory bowel disease (IBD) research and those involved in colorectal adenocarcinoma as interpreted from The Cancer Genome Atlas (TCGA) were retrieved to predict drug targets based on HP-PPIs with F. nucleatum proteome. Prediction of HP-PPIs exhibited 186 interactions contributed by 103 host and 76 bacterial proteins. Bacterial interacting partners were accounted as putative targets. And enrichment analysis of host interacting partners showed statistically enriched terms that were in positive correlation with CRC, atherosclerosis, cardiovascular, osteoporosis, Alzheimer’s and other diseases. Conclusion Subtractive genomics analysis provided a set of target proteins suggested to be indispensable for survival and pathogenicity of F. nucleatum. These target proteins might be considered for designing potent inhibitors to abrogate F. nucleatum infections. From enrichment analysis, it was hypothesized that F. nucleatum infection might enhance CRC progression by simultaneously regulating multiple signaling cascades which could lead to up-regulation of proinflammatory responses, oncogenes, modulation of host immune defense mechanism and suppression of DNA repair system. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0700-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Amit Kumar
- Centre for Bioinformatics, Pondicherry University, Puducherry, 605014, India
| | | | - Basant Kumar Tiwary
- Centre Head, Centre for Bioinformatics, Pondicherry University, Puducherry, 605014, India
| | - Ramadas Krishna
- Centre for Bioinformatics, Pondicherry University, Puducherry, 605014, India.
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69
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Nagy E, Rodriguiz RM, Wetsel WC, MacIver NJ, Hale LP. Reproduction and Growth in a Murine Model of Early Life-Onset Inflammatory Bowel Disease. PLoS One 2016; 11:e0152764. [PMID: 27045690 PMCID: PMC4821577 DOI: 10.1371/journal.pone.0152764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 03/18/2016] [Indexed: 12/16/2022] Open
Abstract
Studies in transgenic murine models have provided insight into the complexity underlying inflammatory bowel disease (IBD), a disease hypothesized to result from an injurious immune response against intestinal microbiota. We recently developed a mouse model of IBD that phenotypically and histologically resembles human childhood-onset ulcerative colitis (UC), using mice that are genetically modified to be deficient in the cytokines TNF and IL-10 (“T/I” mice). Here we report the effects of early life onset of colon inflammation on growth and reproductive performance of T/I mice. T/I dams with colitis often failed to get pregnant or had small litters with pups that failed to thrive. Production was optimized by breeding double homozygous mutant T/I males to females homozygous mutant for TNF deficiency and heterozygous for deficiency of IL-10 (“T/I-het” dams) that were not susceptible to spontaneous colon inflammation. When born to healthy (T/I-het) dams, T/I pups initially gained weight similarly to wild type (WT) pups and to their non-colitis-susceptible T/I-het littermates. However, their growth curves diverged between 8 and 13 weeks, when most T/I mice had developed moderate to severe colitis. The observed growth failure in T/I mice occurred despite a significant increase in their food consumption and in the absence of protein loss in the stool. This was not due to TNF-induced anorexia or altered food consumption due to elevated leptin levels. Metabolic studies demonstrated increased consumption of oxygen and water and increased production of heat and CO2 in T/I mice compared to their T/I-het littermates, without differences in motor activity. Based on the clinical similarities of this early life onset model of IBD in T/I mice to human IBD, these results suggest that mechanisms previously hypothesized to explain growth failure in children with IBD require re-evaluation. The T/I mouse model may be useful for further investigation of such mechanisms and for development of therapies to prevent reproductive complications and/or growth failure in humans with IBD.
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Affiliation(s)
- Eniko Nagy
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Ramona M. Rodriguiz
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina, United States of America
| | - William C. Wetsel
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Nancie J. MacIver
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Laura P. Hale
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, United States of America
- Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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70
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Bruner SD, Jobin C. Intestinal Microbiota in Inflammatory Bowel Disease and Carcinogenesis: Implication for Therapeutics. Clin Pharmacol Ther 2016; 99:585-7. [PMID: 26850686 DOI: 10.1002/cpt.348] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 01/27/2016] [Accepted: 01/31/2016] [Indexed: 01/25/2023]
Abstract
Trillions of bacteria inhabit our intestine, forming a community called the microbiota, whose contributions are essential to maintain host homeostasis. Disruption of this normal microbial-host communication network has deleterious consequences for the host and is associated with intestinal pathologies such as inflammatory bowel diseases (IBD) and colorectal cancer (CRC). Here we present key concepts and mechanisms by which bacteria may participate in intestinal pathology, and discuss possible means to therapeutically target the microbiome.
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Affiliation(s)
- S D Bruner
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - C Jobin
- Department of Medicine, University of Florida, Gainesville, Florida, USA.,Department of Infectious Diseases and Pathology, University of Florida, Gainesville, Florida, USA
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71
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Bian X, Plaza A, Zhang Y, Müller R. Two more pieces of the colibactin genotoxin puzzle from Escherichia coli show incorporation of an unusual 1-aminocyclopropanecarboxylic acid moiety. Chem Sci 2015; 6:3154-3160. [PMID: 28706687 PMCID: PMC5490422 DOI: 10.1039/c5sc00101c] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 03/23/2015] [Indexed: 01/02/2023] Open
Abstract
Colibactin represents a structurally undefined class of bacterial genotoxin inducing DNA damage and genomic instability in mammalian cells, thus promoting tumour development and exacerbating lymphopenia in animal models. The colibactin biosynthetic gene cluster (clb) has been known for ten years and it encodes a hybrid nonribosomal peptide synthetase (NRPS)/polyketide synthase (PKS) assembly line. Nevertheless, the final chemical product(s) remain unknown. Previously, we and others reported several colibactin pathway-related metabolites including N-myristoyl-d-asparagine (1) as part of a prodrug precursor that is cleaved from the putative precolibactin to form active colibactin by the peptidase ClbP. Herein, we report two new colibactin pathway-related metabolites (2 and 3) isolated from a clbP mutant of the probiotic E. coli Nissle 1917 strain. Their structures were established by HRMS and NMR. Compound 2 shows an additional 4-aminopenatanoic acid moiety with respect to 1, while 3 is characterized by the presence of an unusual 7-methyl-4-azaspiro[2.4]hept-6-en-5-one residue. Moreover, we propose the biosynthetic pathway towards both intermediates on the basis of extensive gene inactivation and feeding experiments. The identification of 2 and 3 provides further insight into colibactin biosynthesis including the involvement and formation of a rare 1-aminocyclopropanecarboxylic acid unit. Thus, our work establishes additional steps of the pathway forming the bacterial genotoxin colibactin.
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Affiliation(s)
- Xiaoying Bian
- Department of Microbial Natural Products , Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research (HZI) , Department of Pharmaceutical Biotechnology , Saarland University , Campus C2 3 , 66123 Saarbrücken , Germany . ; Tel: +49-681-30270201
- Shandong University-Helmholtz Institute of Biotechnology , State Key Laboratory of Microbial Technology , School of Life Science , Shandong University , Zhuzhou Road 168 , 266101 Qingdao , P. R. China . ; Tel: +86-531-88363082
| | - Alberto Plaza
- Department of Microbial Natural Products , Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research (HZI) , Department of Pharmaceutical Biotechnology , Saarland University , Campus C2 3 , 66123 Saarbrücken , Germany . ; Tel: +49-681-30270201
| | - Youming Zhang
- Shandong University-Helmholtz Institute of Biotechnology , State Key Laboratory of Microbial Technology , School of Life Science , Shandong University , Zhuzhou Road 168 , 266101 Qingdao , P. R. China . ; Tel: +86-531-88363082
| | - Rolf Müller
- Department of Microbial Natural Products , Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS) , Helmholtz Centre for Infection Research (HZI) , Department of Pharmaceutical Biotechnology , Saarland University , Campus C2 3 , 66123 Saarbrücken , Germany . ; Tel: +49-681-30270201
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