DOCSLIB.ORG

Mucin Utilisation and Host Interactions of the Novel Intestinal

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Mucin Utilisation and Host Interactions of the Novel Intestinal Mucin Utilisation and Host Interactions of the Novel Intestinal Microbe Akkermansia muciniphila Muriel Derrien Promotor Prof. dr. W. M. de Vos Hoogleraar Microbiologie Wageningen Universiteit Co-promotor Dr. E. G. Zoetendal Wetenschappelijk onderzoeker Laboratorium voor Microbiologie Wageningen Universiteit Promotiecomissie Prof. dr. M. R. Müller Wageningen Universiteit Dr. A. C. Ouwehand Danisco Innovation, Kantvik, Finland Dr. H. J. M. Harmsen Rijksuniversiteit Groningen Dr. E. Norin Karolinska Institute, Stockholm, Sweden Dit onderzoek is uitgevoerd binnen de onderzoekschool VLAG Mucin Utilisation and Host Interactions of the Novel Intestinal Microbe Akkermansia muciniphila Muriel Derrien Proefschrift Ter verkrijging van de graad van doctor op gezag van de rector magnificus van Wageningen Universiteit, Prof. dr. M.J. Kropff, in het openbaar te verdedigen op dinsdag 15 mei 2007 des namiddags te half twee in de Aula M. Derrien – Mucin utilisation and host interactions of the novel intestinal microbe Akkermansia muciniphila – 2007 PhD. thesis Wageningen University, Wageningen, The Netherlands, with summary in Dutch and French ISBN: 978-90-8504-644-8 Abstract Mucins are the major organic components of the defence barrier, known as mucus, covering epithelial cells in many organs, including the entire gastrointestinal (GI) tract. Microbes that can associate with mucins benefit from this interaction since they can access nutrients. Mucin- degrading bacteria are therefore an important community that have not been extensively studied as the substrate itself, mucin, is a complex and high molecular weight glycoprotein. The work presented here is focused on the identification and isolation of mucin-degrading bacteria from the GI tract, their degradation of mucin and their interaction with the host. Mucin-degrading bacteria were analysed by combining molecular- and cultivation-based approaches. The faecal mucin-degrading bacterial community was found to be highly diverse and host-specific. A novel isolate, representing a novel genus, was cultured from the highest dilution of the enrichment of a single individual. This intestinal isolate, Akkermansia muciniphila, was found to grow to a limited extent on a very limited amount of substrates but grew efficiently on mucin. Phylogenetic analysis based on 16S rRNA sequences indicated that A. muciniphila belonged to the phylum Verrucomicrobia, which was not known to contain intestinal members. Moreover, 16S rRNA genes from A. muciniphila have been retrieved in several clone libraries derived from either faecal or biopsy samples from human and mice. In addition, A. muciniphila was found to be rather abundant in the GI tract. Based on fluorescent in situ hybridisation and quantitative PCR, A. muciniphila was found to represent an average of 109 cells / g faecal sample. A negative correlation between the concentration of faecal mucin and the number of A. muciniphila was observed, suggesting it to be involved in mucin degradation in vivo. Several specific enzymes, mostly glycosidases were found to be secreted during its growth on mucin that was degraded for a major part (85%). Hence, the specific impact of A. muciniphila on the host was investigated in germ-free mice and compared to that of the non mucin-degrading bacterium L. plantarum. Transcriptomic microarray analysis showed that both A. muciniphila and L. plantarum modulated a similar number of genes but that host response was found to be highly specific for each bacterium, depending on the anatomical location. Amongst the major responses, we could detect for A. muciniphila a regulation of the immune response, cell proliferation, cell adhesion and apoptosis, and for L. plantarum a regulation of the lipid metabolism. Overall, this work has brought new insights into the mucin-degrading community of bacteria, and in particular the role of A. muciniphila, an abundant human mucin-degrading bacterium. Keywords. Mucin, A. muciniphila, mucin degradation, molecular techniques, host response Table of contents Preface Chapter 1 General introduction 11 Chapter 2 Prebiotics and other microbial substrates for gut functionality 33 Chapter 3 Monitoring of the bacterial mucin-degrading consortium 43 Chapter 4 Akkermansia muciniphila gen. nov., sp. nov., a human intestinal 53 mucin-degrading bacterium Chapter 5 Analysis the mucin-degrading enzymes of Akkermansia muciniphila 65 Chapter 6 The mucin-degrader, Akkermansia muciniphila, is an important 75 member of the human intestinal tract. Chapter 7 Mucin secretion and fructooligosaccharides in the intestine: 89 the role of the mucin-degrading bacterium Akkermansia muciniphila Chapter 8 Gene profiling of mice responses after mono-association 101 with the intestinal mucin-degrading bacterium Akkermansia muciniphila and the commensal Lactobacillus plantarum Chapter 9 Summary, concluding remarks and future perspectives 131 Appendix Literature cited 139 Nederlandse samenvatting 156 Résumé en français 159 Acknowledgements 165 About the author 169 List of publications 171 Education 173 Preface The work presented here is focused on the identification and isolation of mucin-degrading bacteria from the gastrointestinal tract, their degradation of mucin, and their interaction with the host. Chapter 1 provides an introduction in the structure and properties of mucin, the known bacteria that degrade mucin, and the interactions between bacteria and the host. Chapter 2 is a review on intestinal substrates used by the intestinal microbiota, including prebiotics and substrates secreted by the host including mucus. Chapter 3 describes the monitoring of faecal bacterial communities able to grow on isolated mucin. Fingerprinting of 16S rRNA amplicons by denaturing gradient gel electrophoresis followed by cloning and sequencing of the amplicons, resulted in the identification of the major populations. Chapter 4 details the isolation from human faeces of a novel bacterium, Akkermansia muciniphila, able to grow on mucin as both carbon and nitrogen source, and its subsequent characterisation by molecular, phylogenetic and physiological approaches. Chapter 5 provides an overview of the repertoire of mucinolytic enzymes of A. muciniphila by using a combination of biochemical and physiological approaches. Chapter 6 describes the validation of a specific probe targeting a part of the 16S rRNA gene of A. muciniphila, and its application in faecal samples for the quantification of A. muciniphila by using fluorescent in situ hybridisation combined with flow cytometry. Chapter 7 aims to describe the relation of the number of cells of A. muciniphila and the amount of mucus produced by human volunteers that were subject to the consumption of fructooligosaccharides (FOS). A possible link between the FOS diet, mucin increase and A. muciniphila population dynamics was investigated. Chapter 8 is addressing the impact on the host by A. muciniphila. Germ-free mice were mono-associated with A. muciniphila and the global transcriptional response was determined by high throughput microarrays representing the genome of the mouse. Chapter 9 summarises the work of the thesis and provides perspectives for future research. à ma famille, [ CHAPTER 1 \ General Introduction The human gastro-intestinal (GI) tract is essentially a tube, which starts from the mouth and ends at the anus. The lumen of the GI tract is continuous with the external environment and only separated from the inside by a single layer of intestinal cells that are covered by a mucus layer. The intestinal lumen is colonised since birth by diverse microbial communities – collectively known as the microbiota - that predominantly consist of bacteria. There is a growing interest in the interactions between the microbiota, the host cells and nutrients as they constitute the three major key players of the intestinal ecosystem that are involved in health and disease. Hence, their main attributes are described here with special attention for the microbiota, the intestinal mucins and their interactions. Chapter 1 The human gastrointestinal tract and its microbiota Following food intake, the digestive process starts in the mouth during mastication and maceration, and the food components are then passed on to the stomach for further treatment by acids and digestive enzymes. The last phase of digestion takes place in the small and large intestine (Fig. 1.1). The small intestine, composed of three distinct anatomical and functional parts, duodenum, jejunum and ileum, plays a major role in absorption of nutrients via action of several enzymes converting carbohydrates into monosaccharides, lipids into fatty acids and glycerol, and proteins into amino acids. Part of the food components are metabolised and subsequently absorbed in the small intestine but the complex ones reach the colon in an intact form for further microbial fermentation. The colon is considered as the metabolically most active site from the GI tract. It starts from the caecum, continues to ascending, transverse and descending colon and finishes at the rectum where the luminal contents leave the body as faeces. From the upper part of the GI tract to the lower part, the pH increases gradually in parallel to concentration of bacteria (Fig. 1.1). Chemical and mechanical digestion Stomach pH 2, 45 cm, transit 2-6 h 105 bacteria /g Duodenum Nutrients uptake Jejunum Small intestine pH 5-6, 5-7 m, transit 3-6 h 106-108 bacteria /g Ileum Caecum Water absorption Large intestine Colon pH 6-8, 1.50 m, transit 15-40 h Rectum 108-101010 bacteria /g
Load more

Recommended publications
  • Prokaryotes (Domains Bacteria & Archaea)
    2/4/15 Prokaryotes (Domains Bacteria & Archaea) KEY POINTS 1. Decomposers: recycle organic and inorganic molecules in environment; makes them available to other organisms. 2. Essential components of symbioses. 3. Encompasses the origins of metabolism and metabolic diversity. 4. Origin of photosynthesis and formation of atmospheric Oxygen Ceno- Meso- zoic zoic ANTIQUITY Humans Paleozoic Colonization of land Animals Origin of solar system and Earth • >3.5 BILLION years old. • Alone for 2 1 4 billion years Proterozoic Archaean Prokaryotes Billions of 2 years ago3 Multicellular eukaryotes Single-celled eukaryotes Atmospheric oxygen General characteristics 1. Small: compare to 10-100µm for 0.5-5µm eukaryotic cell; single-celled; may form colonies. 2. Lack membrane- enclosed organelles. 3. Cell wall present, but different from plant cell wall. 1 2/4/15 General characteristics 4. Occur everywhere, most numerous organisms. – More individuals in a handful of soil then there are people that have ever lived. – By far more individuals in our gut than eukaryotic cells that are actually us. General characteristics 5. Metabolic diversity established nutritional modes of eukaryotes. General characteristics 6. Important decomposers and recyclers 2 2/4/15 General characteristics 6. Important decomposers and recyclers • Form the basis of global nutrient cycles. General characteristics 7. Symbionts!!!!!!! • Parasites • Pathogenic organisms. • About 1/2 of all human diseases are caused by Bacteria General characteristics 7. Symbionts!!!!!!! • Parasites • Pathogenic organisms. • Extremely important in agriculture as well. Pierce’s disease is caused by Xylella fastidiosa, a Gamma Proteobacteria. It causes over $56 million in damage annually in California. That’s with $34 million spent to control it! = $90 million in California alone.
    [Show full text]
  • Gastrointestinal Status and Microbiota Shaping in Amyotrophic Lateral Sclerosis: a New Frontier for Targeting?
    8 Gastrointestinal Status and Microbiota Shaping in Amyotrophic Lateral Sclerosis: A New Frontier for Targeting? Letizia Mazzini1 • Fabiola De Marchi1 • Elena Niccolai2 • Jessica Mandrioli3, Amedeo Amedei2 1ALS Centre, Department of Neurology, Maggiore della Carità Hospital, University of Piemonte Orientale, Novara, Italy; 2Department of Experimental and clinical Medicine, University of Florence, Firenze, Italy; 3Department of Biomedical, Metabolic and Neural Science, University of Modena and Reggio Emilia, Modena, Italy Author for correspondence: Letizia Mazzini, ALS Centre, Department of Neurology, Maggiore della Carità Hospital, University of Piemonte Orientale, Novara, Italy. Email: [email protected] Doi: https://doi.org/10.36255/exonpublications.amyotrophiclateralsclerosis. microbiota.2021 Abstract: Amyotrophic lateral sclerosis (ALS) is a rare and severe neurodegenera- tive disease affecting the upper and lower motor neurons, causing diffuse muscle paralysis. Etiology and pathogenesis remain largely unclear, but several environ- mental, genetic, and molecular factors are thought to be involved in the disease process. Emerging data identify a relationship between gut microbiota dysbiosis and neurodegenerative diseases, such as Parkinson’s disease, Alzheimer’s disease, and ALS. In these disorders, neuroinflammation is being increasingly recognized as a driver for disease onset and progression. Gut bacteria play a crucial role in In: Amyotrophic Lateral Sclerosis. Araki T (Editor), Exon Publications, Brisbane, Australia. ISBN:
    [Show full text]
  • A Generic Large-Scale Cause for Platelet Dysfunction and Depletion in Infection
    Published online: 2020-04-12 THIEME 302 A Champion of Host Defense: A Generic Large-Scale Cause for Platelet Dysfunction and Depletion in Infection Martin J. Page, BSc (Hons)1 Etheresia Pretorius, PhD1 1 Department of Physiological Sciences, Stellenbosch University, Address for correspondence Etheresia Pretorius, PhD, Department of Stellenbosch, South Africa Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch, 7602, South Africa Semin Thromb Hemost 2020;46:302–319. (e-mail: [email protected]). Abstract Thrombocytopenia is commonly associated with sepsis and infections, which in turn are characterized by a profound immune reaction to the invading pathogen. Platelets are one of the cellular entities that exert considerable immune, antibacterial, and antiviral actions, and are therefore active participants in the host response. Platelets are sensitive to surrounding inflammatory stimuli and contribute to the immune response by multiple mechanisms, including endowing the endothelium with a proinflammatory phenotype, enhancing and amplifying leukocyte recruitment and inflammation, promoting the effector functions of immune cells, and ensuring an optimal adaptive immune response. During infection, pathogens and their products influence the platelet response and can even be toxic. However, platelets are able to sense and engage bacteria and viruses to assist in their removal and destruction. Platelets greatly contribute to host defense by multiple mechanisms, including forming immune complexes and aggregates, shedding their granular content, and internalizing pathogens and subsequently being marked for removal. These processes, and the nature of platelet function in general, cause the platelet to be irreversibly consumed in Keywords the execution of its duty. An exaggerated systemic inflammatory response to infection ► platelets can drive platelet dysfunction, where platelets are inappropriately activated and face ► virus immunological destruction.
    [Show full text]
  • Characterization of Α-L-Fucosidase and Other Digestive Hydrolases From
    Acta Tropica 141 (2015) 118–127 Contents lists available at ScienceDirect Acta Tropica journal homepage: www.elsevier.com/locate/actatropica Characterization of ␣-L-fucosidase and other digestive hydrolases from Biomphalaria glabrata Natalia N. Perrella a,b, Rebeca S. Cantinha c,d, Eliana Nakano c, Adriana R. Lopes a,∗ a Laboratory of Biochemistry and Biophysics—Instituto Butantan, São Paulo, Brazil b Programa de Pós Graduac¸ ão Interunidades em Biotecnologia PPIB, Universidade de São Paulo, São Paulo, SP, Brazil c Laboratory of Parasitology—Instituto Butantan, São Paulo, Brazil d Instituto de Pesquisas Energéticas e Nucleares, Universidade de São Paulo, São Paulo, SP, Brazil article info abstract Article history: Schistosoma mansoni is one of the major agents of the disease Schistosomiasis, which is one of the Received 10 February 2014 major global public health concerns. Biomphalaria glabrata is an obligate intermediate mollusc host of Received in revised form 3 July 2014 S. mansoni. Although the development of S. mansoni occurs in the snail hepatopancreas, studies that Accepted 12 August 2014 focus on this organ remain limited. In this study, we biochemically identified five distinct carbohy- Available online 16 September 2014 drases (amylase, maltase, ␣-glucosidase, trehalase, and ␣-L-fucosidase), lipases, and peptidases in the B. glabrata hepatopancreas and focused on the isolation and characterization of the activity of ␣-L- Keywords: fucosidase. The isolated ␣-L-fucosidase has a molecular mass of 141 kDa, an optimum pH of 5.8, and Hepatopancreas ␣ Enzymes is inhibited by Tris, fucose, and 1-deoxyfuconojirimycin. B. glabrata -L-fucosidase is an exoglycosidase ␮ ␣-L-Fucosidase that can hydrolyze the natural substrate fucoidan to fucose residues.
    [Show full text]
  • Glycoproteomics-Based Signatures for Tumor Subtyping and Clinical Outcome Prediction of High-Grade Serous Ovarian Cancer
    ARTICLE https://doi.org/10.1038/s41467-020-19976-3 OPEN Glycoproteomics-based signatures for tumor subtyping and clinical outcome prediction of high-grade serous ovarian cancer Jianbo Pan 1,2,3, Yingwei Hu1,3, Shisheng Sun 1,3, Lijun Chen1, Michael Schnaubelt1, David Clark1, ✉ Minghui Ao1, Zhen Zhang1, Daniel Chan1, Jiang Qian2 & Hui Zhang 1 1234567890():,; Inter-tumor heterogeneity is a result of genomic, transcriptional, translational, and post- translational molecular features. To investigate the roles of protein glycosylation in the heterogeneity of high-grade serous ovarian carcinoma (HGSC), we perform mass spectrometry-based glycoproteomic characterization of 119 TCGA HGSC tissues. Cluster analysis of intact glycoproteomic profiles delineates 3 major tumor clusters and 5 groups of intact glycopeptides. It also shows a strong relationship between N-glycan structures and tumor molecular subtypes, one example of which being the association of fucosylation with mesenchymal subtype. Further survival analysis reveals that intact glycopeptide signatures of mesenchymal subtype are associated with a poor clinical outcome of HGSC. In addition, we study the expression of mRNAs, proteins, glycosites, and intact glycopeptides, as well as the expression levels of glycosylation enzymes involved in glycoprotein biosynthesis pathways in each tumor. The results show that glycoprotein levels are mainly controlled by the expression of their individual proteins, and, furthermore, that the glycoprotein-modifying glycans cor- respond to the protein levels of glycosylation enzymes. The variation in glycan types further shows coordination to the tumor heterogeneity. Deeper understanding of the glycosylation process and glycosylation production in different subtypes of HGSC may provide important clues for precision medicine and tumor-targeted therapy.
    [Show full text]
  • Killing of Gram-Negative Bacteria by Lactoferrin and Lysozyme
    Killing of gram-negative bacteria by lactoferrin and lysozyme. R T Ellison 3rd, T J Giehl J Clin Invest. 1991;88(4):1080-1091. https://doi.org/10.1172/JCI115407. Research Article Although lactoferrin has antimicrobial activity, its mechanism of action is not full defined. Recently we have shown that the protein alters the Gram-negative outer membrane. As this membrane protects Gram-negative cells from lysozyme, we have studied whether lactoferrin's membrane effect could enhance the antibacterial activity of lysozyme. We have found that while each protein alone is bacteriostatic, together they can be bactericidal for strains of V. cholerae, S. typhimurium, and E. coli. The bactericidal effect is dose dependent, blocked by iron saturation of lactoferrin, and inhibited by high calcium levels, although lactoferrin does not chelate calcium. Using differing media, the effect of lactoferrin and lysozyme can be partially or completely inhibited; the degree of inhibition correlating with media osmolarity. Transmission electron microscopy shows that E. coli cells exposed to lactoferrin and lysozyme at 40 mOsm become enlarged and hypodense, suggesting killing through osmotic damage. Dialysis chamber studies indicate that bacterial killing requires direct contact with lactoferrin, and work with purified LPS suggests that this relates to direct LPS-binding by the protein. As lactoferrin and lysozyme are present together in high levels in mucosal secretions and neutrophil granules, it is probable that their interaction contributes to host defense. Find the latest version: https://jci.me/115407/pdf Killing of Gram-negative Bacteria by Lactofernn and Lysozyme Richard T. Ellison III*" and Theodore J. Giehl *Medical and tResearch Services, Department of Veterans Affairs Medical Center, and Division ofInfectious Diseases, Department ofMedicine, University ofColorado School ofMedicine, Denver, Colorado 80220 Abstract (4).
    [Show full text]
  • Diversity in the Extracellular Vesicle-Derived Microbiome of Tissues According to Tumor Progression in Pancreatic Cancer
    cancers Article Diversity in the Extracellular Vesicle-Derived Microbiome of Tissues According to Tumor Progression in Pancreatic Cancer Jin-Yong Jeong 1, Tae-Bum Kim 2 , Jinju Kim 1, Hwi Wan Choi 1, Eo Jin Kim 1, Hyun Ju Yoo 1 , Song Lee 3, Hye Ryeong Jun 3, Wonbeak Yoo 4 , Seokho Kim 5, Song Cheol Kim 3,6,* and Eunsung Jun 1,3,* 1 Department of Convergence Medicine, Asan Institute for Life Sciences, University of Ulsan College of Medicine and Asan Medical Center, Seoul 05505, Korea; [email protected] (J.-Y.J.); [email protected] (J.K.); [email protected] (H.W.C.); [email protected] (E.J.K.); [email protected] (H.J.Y.) 2 Department of Allergy and Clinical Immunology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; [email protected] 3 Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; [email protected] (S.L.); [email protected] (H.R.J.) 4 Environmental Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Korea; [email protected] 5 Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan 49315, Korea; [email protected] 6 Biomedical Engineering Research Center, Asan Institute of Life Science, AMIST, Asan Medical Center, Seoul 05505, Korea * Correspondence: [email protected] (S.C.K.); [email protected] (E.J.); Tel.: +82-2-3010-3936 (S.C.K.); +82-2-3010-1696 (E.J.); Fax: +82-2-474-9027 (S.C.K.); +82-2-474-9027 (E.J.) Received: 13 July 2020; Accepted: 17 August 2020; Published: 19 August 2020 Abstract: This study was conducted to identify the composition and diversity of the microbiome in tissues of pancreatic cancer and to determine its role.
    [Show full text]
  • The Unicellular and Colonial Organisms Prokaryotic And
    The Unicellular and Colonial Organisms Prokaryotic and Eukaryotic Cells As you know, the building blocks of life are cells. Prokaryotic cells are those cells that do NOT have a nucleus. They mostly include bacteria and archaea. These cells do not have membrane-bound organelles. Eukaryotic cells are those that have a true nucleus. That would include plant, animal, algae, and fungal cells. As you can see, to the left, eukaryotic cells are typically larger than prokaryotic cells. Today in lab, we will look at examples of both prokaryotic and eukaryotic unicellular organisms that are commonly found in pond water. When examining pond water under a microscope… The unpigmented, moving microbes will usually be protozoans. Greenish or golden-brown organisms will typically be algae. Microorganisms that are blue-green will be cyanobacteria. As you can see below, living things are divided into 3 domains based upon shared characteristics. Domain Eukarya is further divided into 4 Kingdoms. Domain Kingdom Cell type Organization Nutrition Organisms Absorb, Unicellular-small; Prokaryotic Photsyn., Archaeacteria Archaea Archaebacteria Lacking peptidoglycan Chemosyn. Unicellular-small; Absorb, Bacteria, Prokaryotic Peptidoglycan in cell Photsyn., Bacteria Eubacteria Cyanobacteria wall Chemosyn. Ingestion, Eukaryotic Unicellular or colonial Protozoa, Algae Protista Photosynthesis Fungi, yeast, Fungi Eukaryotic Multicellular Absorption Eukarya molds Plantae Eukaryotic Multicellular Photosynthesis Plants Animalia Eukaryotic Multicellular Ingestion Animals Prokaryotic Organisms – the archaea, non-photosynthetic bacteria, and cyanobacteria Archaea - Microorganisms that resemble bacteria, but are different from them in certain aspects. Archaea cell walls do not include the macromolecule peptidoglycan, which is always found in the cell walls of bacteria. Archaea usually live in extreme, often very hot or salty environments, such as hot mineral springs or deep-sea hydrothermal vents.
    [Show full text]
  • Characterization of the First Cultured Representative of Verrucomicrobia Subdivision 5 Indicates the Proposal of a Novel Phylum
    The ISME Journal (2016) 10, 2801–2816 OPEN © 2016 International Society for Microbial Ecology All rights reserved 1751-7362/16 www.nature.com/ismej ORIGINAL ARTICLE Characterization of the first cultured representative of Verrucomicrobia subdivision 5 indicates the proposal of a novel phylum Stefan Spring1, Boyke Bunk2, Cathrin Spröer3, Peter Schumann3, Manfred Rohde4, Brian J Tindall1 and Hans-Peter Klenk1,5 1Department Microorganisms, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany; 2Department Microbial Ecology and Diversity Research, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany; 3Department Central Services, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany and 4Central Facility for Microscopy, Helmholtz-Centre of Infection Research, Braunschweig, Germany The recently isolated strain L21-Fru-ABT represents moderately halophilic, obligately anaerobic and saccharolytic bacteria that thrive in the suboxic transition zones of hypersaline microbial mats. Phylogenetic analyses based on 16S rRNA genes, RpoB proteins and gene content indicated that strain L21-Fru-ABT represents a novel species and genus affiliated with a distinct phylum-level lineage originally designated Verrucomicrobia subdivision 5. A survey of environmental 16S rRNA gene sequences revealed that members of this newly recognized phylum are wide-spread and ecologically important in various anoxic environments ranging from hypersaline sediments to wastewater and the intestine of animals. Characteristic phenotypic traits of the novel strain included the formation of extracellular polymeric substances, a Gram-negative cell wall containing peptidoglycan and the absence of odd-numbered cellular fatty acids. Unusual metabolic features deduced from analysis of the genome sequence were the production of sucrose as osmoprotectant, an atypical glycolytic pathway lacking pyruvate kinase and the synthesis of isoprenoids via mevalonate.
    [Show full text]
  • Akkermansia Muciniphila Ameliorates the Age-Related Decline in Colonic
    van der Lugt et al. Immunity & Ageing (2019) 16:6 https://doi.org/10.1186/s12979-019-0145-z RESEARCH Open Access Akkermansia muciniphila ameliorates the age-related decline in colonic mucus thickness and attenuates immune activation in accelerated aging Ercc1−/Δ7 mice Benthe van der Lugt1*†, Adriaan A. van Beek2,3†, Steven Aalvink4, Ben Meijer3, Bruno Sovran5, Wilbert P. Vermeij6,7, Renata M. C. Brandt6, Willem M. de Vos4,8, Huub F. J. Savelkoul3, Wilma T. Steegenga1 and Clara Belzer4* Abstract Background: The use of Akkermansia muciniphila as potential therapeutic intervention is receiving increasing attention. Health benefits attributed to this bacterium include an improvement of metabolic disorders and exerting anti-inflammatory effects. The abundance of A. muciniphila is associated with a healthy gut in early mid- and later life. However, the effects of A. muciniphila on a decline in intestinal health during the aging process are not investigated yet. We supplemented accelerated aging Ercc1−/Δ7 mice with A. muciniphila for 10 weeks and investigated histological, transcriptional and immunological aspects of intestinal health. Results: The thickness of the colonic mucus layer increased about 3-fold after long-term A. muciniphila supplementation and was even significantly thicker compared to mice supplemented with Lactobacillus plantarum WCFS1. Colonic gene expression profiles pointed towards a decreased expression of genes and pathways related to inflammation and immune function, and suggested a decreased presence of B cells in colon. Total B cell frequencies in spleen and mesenteric lymph nodes were not altered after A. muciniphila supplementation. Mature and immature B cell frequencies in bone marrow were increased, whereas B cell precursors were unaffected.
    [Show full text]
  • Identification and Characterisation of Mucin Abnormalities in the Ganglionic Bowel in Hirschsprung’S Disease
    IDENTIFICATION AND CHARACTERISATION OF MUCIN ABNORMALITIES IN THE GANGLIONIC BOWEL IN HIRSCHSPRUNG’S DISEASE By Ruth Marian Speare Submitted for MD (Res) 1 Abstract Hirschsprung’s disease (HD) is a congenital abnormality of unknown origin, characterised by a lack of ganglion cells in the distal colon which results in functional colonic obstruction. The major cause of morbidity and mortality in these children results from an inflammatory condition called enterocolitis. Mucins are large glycoproteins produced by intestinal cells which are a vital part of the colonic defensive barrier to infection. Previous work has found that this barrier is deficient in children with HD in the aganglionic colon and in the immediately adjacent ganglionic colon and that this is related to the risk of developing enterocolitis. This study aimed to further investigate the mucin defensive barrier in a greater region of the ganglionic colon in HD, to establish the extent of any mucin deficiencies and whether these were confined to a limited region close to the aganglionic colon. Mucosal biopsies were collected at intervals along the colon at the time of corrective surgery or colostomy closure in the controls. Organ culture with radioactive mucin precursors was performed and the mucin produced was purified and analysed, results quantified by DNA content in the sample. Lectin binding studies were also carried out. Patients were found to produce lower levels of new mucins most distally, but much higher levels five centimetres proximal when compared to controls. The rest of the colon studied also showed changes in mucin production, with a lack of production of gel-forming mucins and sulphated secreted mucins in Hirschsprung’s disease higher up the colon.
    [Show full text]
  • The Microbiota-Produced N-Formyl Peptide Fmlf Promotes Obesity-Induced Glucose
    Page 1 of 230 Diabetes Title: The microbiota-produced N-formyl peptide fMLF promotes obesity-induced glucose intolerance Joshua Wollam1, Matthew Riopel1, Yong-Jiang Xu1,2, Andrew M. F. Johnson1, Jachelle M. Ofrecio1, Wei Ying1, Dalila El Ouarrat1, Luisa S. Chan3, Andrew W. Han3, Nadir A. Mahmood3, Caitlin N. Ryan3, Yun Sok Lee1, Jeramie D. Watrous1,2, Mahendra D. Chordia4, Dongfeng Pan4, Mohit Jain1,2, Jerrold M. Olefsky1 * Affiliations: 1 Division of Endocrinology & Metabolism, Department of Medicine, University of California, San Diego, La Jolla, California, USA. 2 Department of Pharmacology, University of California, San Diego, La Jolla, California, USA. 3 Second Genome, Inc., South San Francisco, California, USA. 4 Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA. * Correspondence to: 858-534-2230, [email protected] Word Count: 4749 Figures: 6 Supplemental Figures: 11 Supplemental Tables: 5 1 Diabetes Publish Ahead of Print, published online April 22, 2019 Diabetes Page 2 of 230 ABSTRACT The composition of the gastrointestinal (GI) microbiota and associated metabolites changes dramatically with diet and the development of obesity. Although many correlations have been described, specific mechanistic links between these changes and glucose homeostasis remain to be defined. Here we show that blood and intestinal levels of the microbiota-produced N-formyl peptide, formyl-methionyl-leucyl-phenylalanine (fMLF), are elevated in high fat diet (HFD)- induced obese mice. Genetic or pharmacological inhibition of the N-formyl peptide receptor Fpr1 leads to increased insulin levels and improved glucose tolerance, dependent upon glucagon- like peptide-1 (GLP-1). Obese Fpr1-knockout (Fpr1-KO) mice also display an altered microbiome, exemplifying the dynamic relationship between host metabolism and microbiota.
    [Show full text]