A novel, butyrate-producing Gram-positive bacterium from the human gut, Hoskinsella mucinolytica, selectively targets N-acetylhexosamine sugars in host mucins
Ontology highlight
ABSTRACT: We used culturing of fecal sample enrichments on solid medium containing gastric mucin as the main carbon source to isolate a novel bacterium that is largely restricted to using the N-acetylglucosamine and N-acetylgalactosamine sugars from mucin. This butyrate-producing bacterium accesses these sugars from both polymeric gastric mucin and chemically released oligosaccharides and has a genome with correspondingly restricted carbohydrate-active enzyme content. Sequencing data was curated to determine gene expression profiles when comparing N-acetylgalactosamine, N-acetylglucosamine, gastric mucin oligosaccharides and cellobiose.
Project description:A bacterial nursling stool isolate, Bifidobacterium breve UCC2003, encodes two putative sulfatases. The sulfated monosaccharide N-acetylglucosamine-6-sulfate (GlcNAc-6-S) was shown to support growth of B. breve UCC2003, while three other tested sulfated monosaccharides, N-acetylglucosamine-3-sulfate, N-acetylgalactosamine-3-sulfate and N-acetylgalactosamine-6-sulfate, did not. Using a combination of transcriptomic and functional genomic approaches, a gene cluster, designated ats2, was shown to be specifically required for GlcNAc-6-S metabolism. Transcription of the ats2 cluster is shown to be regulated by a ROK-family transcriptional repressor. Expression profiling by array
Project description:The human gut microbiota is crucial for degrading dietary fibres from the diet. However, some of these bacteria can also degrade host glycans, such as mucins, the main component of the protective gut mucus layer. Specific microbiota species and mucin degradation patterns are associated with inflammatory processes in the colon. Yet, it remains unclear how the utilization of mucin glycans affects the degradation of dietary fibres by the human microbiota. Here, we used three dietary fibres (apple pectin, β-glucan and xylan) to study in vitro the dynamics of colon mucin and dietary fibre degradation by the human faecal microbiota. The dietary fibres showed clearly distinguishing modulatory effects on faecal microbiota composition. The utilization of colon mucin in cultures led to alterations in microbiota composition and metabolites. Metaproteome analysis showed the central role of the Bacteroides in degradation of complex fibres while Akkermansia muciniphila was the main degrader of colonic mucin. This work demonstrates the intricacy of complex glycan metabolism by the gut microbiota and how the utilization of host glycans leads to alterations in the metabolism of dietary fibres. Metaproteomics analysis of this data reveals the functional activities of the bacteria in consortia, by this contributing to a better understanding of the complex metabolic pathways within the human microbiota that can be manipulated to maximise beneficial microbiota-host interactions. In this study two different mucin samples were used: commercial porcine gastric mucin and in house prepared porcine colonic mucin. This dataset analyses the proteome of: A) autoclaved porcine colonic mucin; B) not autoclaved porcine colonic mucin; C) porcine gastric mucin.
Project description:Transcription factor Foxq1 controls mucin gene expression and granule content in mouse stomach surface mucous cells ; Background and Aims: The gastric mucosa provides a stringent epithelial barrier and produces acid and enzymes that initiate digestion. In this regenerating tissue, progenitors differentiate continually into 4 principal specialized cell types, yet underlying mechanisms of differentiation are poorly understood. We identified stomach-restricted expression of the forkhead transcription factor FOXQ1. Methods: We used a combination of genetic, histochemical, ultrastructural and molecular analysis to study gastric cell lineages with respect to FOXQ1. Results: Within the developing and adult gastrointestinal tract, Foxq1 mRNA is restricted to the stomach, expressed prominently in foveolar (pit) cells, the abundant mucin-producing cells that line the mucosal surface, and required for their complete differentiation. Mice carrying Foxq1 coding mutations show virtual absence of mRNA and protein for the backbone of the predominant stomach mucin, MUC5AC. These observations correspond to a paucity of foveolar-cell secretory vesicles and notable loss of stomach but not intestinal mucus. Transcriptional profiling identified a surprisingly restricted set of genes with altered expression in Foxq1 mutant stomachs. MUC5AC is a highly tissue-restricted product that similarly depends on FOXQ1 in its other major site of expression, conjunctival goblet cells. Conclusions: Taken together, these observations imply that promotion of gastric MUC5AC synthesis is a primary, cell-autonomous function of FOXQ1. This study is the first to implicate a transcription factor in terminal differentiation of foveolar cells and begins to define the requirements to assemble highly specialized organelles and cells in the gastric mucosa. DOI: 10.1053/j.gastro.2008.04.019 Experiment Overall Design: RNA from stomach antrum from 2 of each Satin, Beige, and BL6 mice were compared using microarray analysis.
Project description:Transcription factor Foxq1 controls mucin gene expression and granule content in mouse stomach surface mucous cells Background and Aims: The gastric mucosa provides a stringent epithelial barrier and produces acid and enzymes that initiate digestion. In this regenerating tissue, progenitors differentiate continually into 4 principal specialized cell types, yet underlying mechanisms of differentiation are poorly understood. We identified stomach-restricted expression of the forkhead transcription factor FOXQ1. Methods: We used a combination of genetic, histochemical, ultrastructural and molecular analysis to study gastric cell lineages with respect to FOXQ1. Results: Within the developing and adult gastrointestinal tract, Foxq1 mRNA is restricted to the stomach, expressed prominently in foveolar (pit) cells, the abundant mucin-producing cells that line the mucosal surface, and required for their complete differentiation. Mice carrying Foxq1 coding mutations show virtual absence of mRNA and protein for the backbone of the predominant stomach mucin, MUC5AC. These observations correspond to a paucity of foveolar-cell secretory vesicles and notable loss of stomach but not intestinal mucus. Transcriptional profiling identified a surprisingly restricted set of genes with altered expression in Foxq1 mutant stomachs. MUC5AC is a highly tissue-restricted product that similarly depends on FOXQ1 in its other major site of expression, conjunctival goblet cells. Conclusions: Taken together, these observations imply that promotion of gastric MUC5AC synthesis is a primary, cell-autonomous function of FOXQ1. This study is the first to implicate a transcription factor in terminal differentiation of foveolar cells and begins to define the requirements to assemble highly specialized organelles and cells in the gastric mucosa. Keywords: mutant mouse stomach
Project description:Mucins and glycoproteins with mucin-like regions contain densely O-glycosylated domains often found in tandem repeat (TR) sequences. These O-glycodomains have traditionally been difficult to characterize because of resistance to proteolytic digestion, and knowledge of positions of O-glycans is particularly limited for these regions. Mucin O-glycodomains are believed to contain important binding cues for endogenous lectin receptors and the microbiota, and it is important to develop strategies to characterize and produce these abundant molecules. Here, we took advantage of our recently developed glycoengineered cell-based platform for display and production of mucin TR reporters with custom designed O-glycosylation to characterize O-glycodomains derived from mucins and mucin-like glycoproteins. We combined intact mass and bottom-up site-specific analysis for mapping O-glycosites in MUC2, MUC20, MUC21, PSGL-1, and Syndecan-3. We found that all the potential Ser/Thr positions in these O-glycodomains were O-glycosylated when expressed in HEK293 SimpleCells (Tn-glycoform). Interestingly, while all the sites in TRs derived from secreted mucins were almost fully occupied, positions in TRs from a subset of transmembrane mucins were less efficiently processed. We further used the mucin TR reporters to characterize cleavage sites of the StcE and BT4244 glycoproteases, revealing a more restricted substrate specificities than reported. Finally, we used these for bottom-up analysis of isolated ovine submaxillary mucin (OSM) and identified the gene. The study provides insight into O-glycosylation of mucins and mucin-like domains and the strategies developed open up for wider analysis of native mucins.
Project description:Kees2018 - Genome-scale constraint-based
model of the mucin-degrader Akkermansia
muciniphila
This model is described in the article:
Model-driven design of a
minimal medium for Akkermansia muciniphila confirms mucus
adaptation.
van der Ark KCH, Aalvink S,
Suarez-Diez M, Schaap PJ, de Vos WM, Belzer C.
Microb Biotechnol 2018 Jan; :
Abstract:
The abundance of the human intestinal symbiont Akkermansia
muciniphila has found to be inversely correlated with several
diseases, including metabolic syndrome and obesity.
A. muciniphila is known to use mucin as sole carbon and
nitrogen source. To study the physiology and the potential for
therapeutic applications of this bacterium, we designed a
defined minimal medium. The composition of the medium was based
on the genome-scale metabolic model of A. muciniphila and
the composition of mucin. Our results indicate that
A. muciniphila does not code for GlmS, the enzyme that
mediates the conversion of fructose-6-phosphate (Fru6P) to
glucosamine-6-phosphate (GlcN6P), which is essential in
peptidoglycan formation. The only annotated enzyme that could
mediate this conversion is Amuc-NagB on locus Amuc_1822. We
found that Amuc-NagB was unable to form GlcN6P from Fru6P at
physiological conditions, while it efficiently catalyzed the
reverse reaction. To overcome this inability,
N-acetylglucosamine needs to be present in the medium for
A. muciniphila growth. With these findings, the
genome-scale metabolic model was updated and used to accurately
predict growth of A. muciniphila on synthetic media. The
finding that A. muciniphila has a necessity for GlcNAc,
which is present in mucin further prompts the adaptation to its
mucosal niche.
This model is hosted on
BioModels Database
and identified by:
MODEL1710040000.
To cite BioModels Database, please use:
Chelliah V et al. BioModels: ten-year
anniversary. Nucl. Acids Res. 2015, 43(Database
issue):D542-8.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:Symbiotic interactions between humans and our communities of resident gut microbes (microbiota) play many roles in health and disease. Some gut bacteria utilize mucus as a nutrient source and can under certain conditions damage the protective barrier it forms, increasing disease susceptibility. We investigated how Ruminococcus torques—a known mucin-degrader that remains poorly studied despite its implication in inflammatory bowel diseases (IBDs)— degrades mucin glycoproteins or their component O-linked glycans to understand its effects on the availability of mucin-derived nutrients for other bacteria. We found that R. torques utilizes both mucin glycoproteins and released oligosaccharides from gastric and colonic mucins, degrading these substrates with a panoply of mostly constitutively expressed, secreted enzymes. Investigation of mucin oligosaccharide degradation by R. torques revealed strong fucosidase, sialidase and b1,4-galactosidase activities. There was a lack of detectable sulfatase and weak β1,3-galactosidase degradation, resulting in accumulation of glycans containing these structures on mucin polypeptides. While the Gram-negative symbiont, Bacteroides thetaiotaomicron grows poorly on mucin glycoproteins, we demonstrate a clear ability of R. torques to liberate products from mucins, making them accessible to B. thetaiotaomicron. This work underscores the diversity of mucin-degrading mechanisms in different bacterial species and the probability that some species are contingent on others for the ability to more fully access mucin-derived nutrients. The ability of R. torques to directly degrade a variety of mucin and mucin glycan structures and unlock released glycans for other species suggests that it is a keystone mucin degrader, which may contribute to its association with IBD.
Project description:The co-utilization of hexoses and pentoses derived from lignocellulose is an attractive trait for in microorganisms considered for consolidated biomass processing to biofuels. This issue was examined for the H2-producing, extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus growing on oligosaccharides (composed of glucose and xylose) compared to monosaccharides. Based on the whole-genome transcriptional response analysis and comparative genomics, carbohydrate specificities for transport systems could be proposed for a number of the 24 putative carbohydrate ATP-binding cassette (ABC) transporters in the C. saccharolyticus genome. Transcriptome analysis showed different transporters were utilized for uptake of oligosaccharides than those used for monosaccharides uptake. No evidence for catabolite repression was noted for either growth on multi-sugar mixtures or in the corresponding transcriptomes. C. saccharolyticus was subcultured (overnight) seven times on the substrate of interest in modified DSMZ 640 medium before inoculating a 1-liter batch containing 0.5 gram substrate per liter. Cells were grown at 70 °C until mid-logarithmic phase (3-5*107) and harvested by rapid cooling to 4 °C and centrifugation and then stored at -80 °C. To elucidate the transporters plus the central carbon metabolic pathways and their regulation utilized on the different sugars, transcriptome analysis was performed after growth on xylan (oat spelt), xyloglucan, xylogluco-oligosaccharides, glucose and xylose.
Project description:The purpose of this project was to determine the whole transcriptome response of Bifidobacterium bifidum SC555 to pooled and individual human milk oligosaccharides (HMO) relative to lactose Bacterial isolates grown on lactose, pooled human milk oligosaccharides (HMO), lacto-N-tetraose (LNT), lacto-N-neotetraose (LNnT), 2âfucosyllactose (2âFL), 3-fucosyllactose (3FL), 6âsialyllactose (6âSL) and porcine mucin (MUC). RNA was extracted and sequenced, in duplicate, on an Illumina HiSeq. Early, mid, and late timepoints in response to pooled HMO were additionally sequenced in duplicate.
Project description:Symbiotic interactions between humans and our communities of resident gut microbes (microbiota) play many roles in health and disease. Some gut bacteria utilize mucus as a nutrient source and can under certain conditions damage the protective barrier it forms, increasing disease susceptibility. We investigated how Ruminococcus torques—a known mucin-degrader that remains poorly studied despite its implication in inflammatory bowel diseases (IBDs)— degrades mucin glycoproteins or their component O-linked glycans to understand its effects on the availability of mucin-derived nutrients for other bacteria. We found that R. torques utilizes both mucin glycoproteins and released oligosaccharides from gastric and colonic mucins, degrading these substrates with a panoply of mostly constitutively expressed, secreted enzymes. Investigation of mucin oligosaccharide degradation by R. torques revealed strong fucosidase, sialidase and 1,4-galactosidase activities. There was a lack of detectable sulfatase and weak β1,3-galactosidase degradation, resulting in accumulation of glycans containing these structures on mucin polypeptides. While the Gram-negative symbiont, Bacteroides thetaiotaomicron grows poorly on mucin glycoproteins, we demonstrate a clear ability of R. torques to liberate products from mucins, making them accessible to B. thetaiotaomicron. This work underscores the diversity of mucin-degrading mechanisms in different bacterial species and the probability that some species are contingent on others for the ability to more fully access mucin-derived nutrients. The ability of R. torques to directly degrade a variety of mucin and mucin glycan structures and unlock released glycans for other species suggests that it is a keystone mucin degrader, which may contribute to its association with IBD.