Regulation of Antimicrobial Peptides in the Gastrointestinal Tract PDF Download

Author: Zora Teltschik
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description

Author: Zora Katharina Teltschik
Publisher:
ISBN:
Category : Gastrointestinal system
Languages : en
Pages :

View

Book Description

Author: Chi Hin Cho
Publisher: Academic Press
ISBN: 0128143207
Category : Science
Languages : en
Pages : 188

View

Book Description
Antimicrobial peptides (AMPs), including cathelicidins and defensins are host defence peptides that carry out multiple roles in the gastrointestinal (GI) tract. Antimicrobial Peptides in Gastrointestinal Diseases presents knowledge about the physiological functions and pharmacological actions of AMPs in inflammation, cancer, and further infection of the GI tract. The book provides coverage from the basic research to clinical application for GI diseases. Current research and development of AMPs is presented, opening the way for further work on these peptides, not only in the context of GI diseases, but also for similar pathologies in other organs. AMPs are key to the regulation of human microbiome and second line defence in the GI mucosa, prevent colonization of pathogens and modulation of innate response to invading pathogens, and modify immunological reactions during inflammatory processes and oncogenic development in the GI mucosa. More importantly, AMPs possess diversified anti-microbial actions against various infectious diseases in the GI tract. With these physiological functions and pharmacological actions, AMPs have significant potential as therapeutic agents for the treatment of inflammation, cancer and further infection in the GI tract. Provides an overview of AMPs, particularly cathelicidin and defensin, in different diseases Covers inflammation and ulcer repair in the stomach and colon and carcinogenesis in the GI tract Presents AMP information and knowledge in a concise manner Gives useful information on all aspects of AMPs Promotes research on AMPs and their development as drugs, from bench, to clinical application

Author: Pieter S. Hiemstra
Publisher: Springer Science & Business Media
ISBN: 3034805411
Category : Medical
Languages : en
Pages : 389

View

Book Description
Antimicrobial peptides have been the subject of intense research in the past decades, and are now considered as an essential part of the defense system in bacteria, plants, animals and humans. his book provides an update on these effector molecules of the innate immune system both for researchers who are already actively involved in the area, and for those with a general interest in the topic. The book starts with an overview of the evolution of cysteine-containing antimicrobial peptides (including defensins), and the role of these peptides in host defense in plants and micro-organisms. The realization that antimicrobial peptides also display functions distinct from their direct antimicrobial action is the focus of the next chapters, and puts these peptides center stage in immunity and wound repair. Further chapters discuss the role of antimicrobial peptides in disease, by providing an overview of mechanisms in bacterial resistance to antimicrobial peptides and a discussion of their role in inflammatory bowel disease, cystic fibrosis lung disease and chronic obstructive pulmonary disease. Finally, the book shows how knowledge of the function of antimicrobial peptides and their regulation can be used to design new therapies for inflammatory and infectious disorders. This is a very important area of research because of the increase in resistance of micro-organisms to conventional antibiotics. Therefore the use of synthetic or recombinant peptides, or agents that stimulate the endogenous production of antimicrobial peptides, provides an attractive alternative for conventional antibiotics.

Author: Yanyan Li
Publisher: Springer
ISBN: 1493910108
Category : Medical
Languages : en
Pages : 113

View

Book Description
Lasso peptides form a growing family of fascinating ribosomally-synthesized and post-translationally modified peptides produced by bacteria. They contain 15 to 24 residues and share a unique interlocked topology that involves an N-terminal 7 to 9-residue macrolactam ring where the C-terminal tail is threaded and irreversibly trapped. The ring results from the condensation of the N-terminal amino group with a side-chain carboxylate of a glutamate at position 8 or 9, or an aspartate at position 7, 8 or 9. The trapping of the tail involves bulky amino acids located in the tail below and above the ring and/or disulfide bridges connecting the ring and the tail. Lasso peptides are subdivided into three subtypes depending on the absence (class II) or presence of one (class III) or two (class I) disulfide bridges. The lasso topology results in highly compact structures that give to lasso peptides an extraordinary stability towards both protease degradation and denaturing conditions. Lasso peptides are generally receptor antagonists, enzyme inhibitors and/or antibacterial or antiviral (anti-HIV) agents. The lasso scaffold and the associated biological activities shown by lasso peptides on different key targets make them promising molecules with high therapeutic potential. Their application in drug design has been exemplified by the development of an integrin antagonist based on a lasso peptide scaffold. The biosynthesis machinery of lasso peptides is therefore of high biotechnological interest, especially since such highly compact and stable structures have to date revealed inaccessible by peptide synthesis. Lasso peptides are produced from a linear precursor LasA, which undergoes a maturation process involving several steps, in particular cleavage of the leader peptide and cyclization. The post-translational modifications are ensured by a dedicated enzymatic machinery, which is composed of an ATP-dependent cysteine protease (LasB) and a lactam synthetase (LasC) that form an enzymatic complex called lasso synthetase. Microcin J25, produced by Escherichia coli AY25, is the archetype of lasso peptides and the most extensively studied. To date only around forty lasso peptides have been isolated, but genome mining approaches have revealed that they are widely distributed among Proteobacteria and Actinobacteria, particularly in Streptomyces, making available a rich resource of novel lasso peptides and enzyme machineries towards lasso topologies.

Author: Jürgen Harder
Publisher: Springer
ISBN: 3319241990
Category : Medical
Languages : en
Pages : 161

View

Book Description
This book focuses on the importance of human antimicrobial peptides (AMP) in keeping the host healthy and preventing infectious diseases. The first chapters deal with several examples of the role of AMP in different epithelial organs (skin and wound healing, eye, lung, genito-urinary tract, gut), which are exposed to different kinds of infectious microorganisms and as a result produce different patterns of AMP. Examples of the dysregulation of AMP expression and function promoting infections are discussed. The capacity of AMP to restrict the availability of essential metals to bacteria as an efficient antibacterial strategy in nutritional immunity is discussed in the next chapter. Our current understanding of how vitamin D, the sunshine vitamin, influences AMP-expression and how this can affect our health is also addressed. Last but not least, the role of AMP in HIV infection and the immunomodulatory properties of AMP highlight the diverse facets of AMP in host immunity. AMP’s specific functions, including in fighting multi-resistant bacteria, suggest that they may offer therapeutic benefits – a question that is discussed in the final chapter.

Author: Natalie Fischer
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description
Les peptides antimicrobiens (PAMs) sont des effecteurs de l'immunité innée et exercent leur activité microbicide sur un spectre de microorganismes. Au niveau de l'intestin, leur sécrétion est directement impliquée dans les processus homéostatiques existant entre un hôte et son microbiote. Ces dernières années, plusieurs études ont démontré une corrélation entre le niveau d'expression des PAMs et la susceptibilité des individus à différentes pathologies. Les PAMs peuvent être exprimés constitutivement ou de manière inductible. Dans les deux cas, les mécanismes de régulation (épi)génétique pour contrôler leur expression sont méconnus.Le but de ces travaux de thèse a été d'étudier la composante (épi)génétique des régulations contrôlant l'expression des gènes codant les PAMs. Utilisant un modèle de cellules épithéliales intestinales humaines exposées à des molécules inhibitrices de l'activité d'enzymes modifiant la chromatine, et stimulées par la bactérie Escherichia coli, nous avons identifié l'importance du processus d'acétylation dans l'expression des ces gènes. Nous avons montré que l'inhibition des enzymes de la famille des histones déacétylases augmente significativement le niveau d'induction des gènes antimicrobiens comme la béta-défensine-2, sans impacter celui des gènes pro-inflammatoires comme l'interleukine 8. Enfin, nous avons étudié le mécanisme moléculaire sous-jacent à cette observation, notamment le rôle du facteur de transcription NF- B et celui de l'histone acétyltransférase p300. Ces travaux démontrent l'existence d'un mécanisme (épi)génétique permettant de réguler différentiellement le niveau d'induction des gènes antimicrobiens et pro-inflammatoires.

Author: Hubert Vaudry
Publisher: Frontiers Media SA
ISBN: 2889455378
Category :
Languages : en
Pages : 282

View

Book Description
Regulatory peptides represent the most diverse and versatile family of messenger molecules. They are produced by all living organisms from bacteria to mammals. They are involved in a wide variety of biological functions. Biologically active peptides and their receptors thus constitute an unlimited source of inspiration for the development of innovative drugs and cosmetics. The present eBook is a unique collection of research articles and reviews that provide a representative examplification of the latest progress in regulatory peptide research.

Author: David A. Phoenix
Publisher: John Wiley & Sons
ISBN: 9783527332632
Category : Science
Languages : en
Pages : 0

View

Book Description
In this text, the small team of expert authors presents the field in a comprehensive and accessible manner that is well suited for students and junior researchers. The result is a highly readable and systematically structured introduction to antimicrobial peptides, their structure, biological function and mode of action. The authors point the way towards a rational design of this potentially highly effective new class of clinical antibiotics on the brink of industrial application. They do this by discussing their design principles, target membranes and structure-activity relationships. The final part of the book describes recent successes in the application of peptides as anticancer agents.

Author: Yan Campbell
Publisher:
ISBN:
Category : Bile acids
Languages : en
Pages : 124

View

Book Description
The human cathelicidin antimicrobial peptide (CAMP) is a broad spectrum microbicidal agent and modulator of both the innate and adaptive immune system. It is induced by 1,25-dihydroxyvitamin D (1,25(OH)2D3) through activation of the vitamin D receptor (VDR) and primary bile salts through activation of the xenobiotic nuclear receptor farnesoid X receptor (FXR). Both receptors are expressed by enterohepatic and gastrointestinal (GI) tissues and play important roles in GI immunity and homeostasis. It has been demonstrated by us and others that plant polyphenol xanthohumol (XN) acts as an FXR ligand, but its regulation of CAMP gene expression has not been determined. We hypothesize that plant polyphenols obtained in the diet act as ligands for FXR and regulate expression of the CAMP gene in the GI tract thereby promoting gastrointestinal health through improved barrier defense against infection and inflammation. In this study, we demonstrate that XN induces BSEP (bile acid export pump) and human CAMP promoter activity via FXR. This activation appears to require some combination of the vitamin D response element (VDRE) site in the CAMP promoter and a potential FXR response element (FXRE) located in the third exon of the gene. In addition, XN and its metabolite 8-prenylnaringenin (8-PN) induced the mRNA expression of several FXR target genes including: BSEP, SHP (small heterodimer partner), IBABP (ileal bile acid binding protein), CAMP and FXR in biliary carcinoma cell lines. Combinations of 1,25(OH)2D3 and either XN or 8-PN cooperatively induced endogenous CAMP gene expression in cells. We conclude that the plant polyphenol XN and its metabolite 8-PN act as FXR ligands and regulate expression of the human CAMP gene alone or in combination with 1,25(OH)2D3. A second distinct project used immunohistochesmitry (IHC), Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) to characterize a transgenic mouse that carries the human CAMP gene. In the transgenic mice fed a normal diet, the human CAMP gene is expressed in immune and epithelial barrier cells and treatment of tissues with 1,25(OH)2D3, including those from the GI tract, induced expression of the human, but not the mouse gene. This study advances our understanding of human CAMP gene regulation by FXR and also helps establish the mouse as a reliable model system that can be used in future studies to determine the importance of CAMP gene expression in human health.