Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1014259 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Background: Idiopathic Chronic Diarrhea (ICD) is a common cause of morbidity and mortality among juvenile rhesus macaques. Characterized by chronic inflammation of the colon and repeated bouts of diarrhea, ICD is largely unresponsive to medical interventions including corticosteroid, antiparasitic and antibiotic treatments. Although ICD is accompanied by large disruptions in the composition of the commensal gut microbiome, no single pathogen has been concretely identified as responsible for the onset and continuation of the disease. Results: Fecal samples were collected from twelve ICD-diagnosed macaques and twelve age and sex-matched controls. RNA was extracted for metatranscriptomic analysis of species and activity within the gut microbiome. Using SAMSA2, these samples were contrasted to identify shifts both in overall organism activity and functional activity. Bacterial, fungal, archaeal, protozoan, and macaque (host) transcripts were simultaneously assessed. ICD-afflicted animals were characterized by increased activity of known bacterial pathogens and by decreased activity of archaeal methanogens. Interestingly, known fungal opportunists were not increased in ICD, nor were the usual enteric protozoans, although Trichomonas activity is up-regualted. Known mucin degrading organisms and mucin-degrading enzymes were up-regulated in the fecal microbiomes of ICD-afflicted animals. Assessment of colon sections using immunohistochemistry confirmed differential mucin composition between healthy control and ICD animals. Finally, assessment of host-derived transcripts confirms colonic inflammation and suggests that the lumen is infiltrated by granulocytes. Conclusions: The simultaneous profiling of bacterial, fungal, archaeal, protozoan, and macaque transcripts from stool samples suggests that ICD of rhesus macaques is associated with increased pathogen activity and altered mucin degradation.
2019-03-09 | GSE108572 | GEO
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.
2024-06-19 | GSE262875 | GEO
Project description:Mucins are functionally implicated in a range of human pathologies, including cystic fibrosis, influenza, bacterial endocarditis, gut dysbiosis, and cancer. These observations have motivated the study of mucin biosynthesis as well as development of strategies for inhibition of mucin glycosylation. Mammalian pathways for mucin catabolism, however, have remained underexplored. The canonical view, derived from analysis of N-glycoconjugates in human lysosomal storage disorders, is that proteolysis and glycan degradation occur largely independently. Here, we challenge this view by providing genetic and biochemical evidence supporting mammalian proteolysis of heavily O-glycosylated mucin domains, without prior deglycosylation. Using activity screening coupled with mass spectrometry we ascribed mucin-degrading activity in murine liver to the lysosomal protease cathepsin D. Knockout of cathepsin D in a murine model of the human lysosomal storage disorder neuronal ceroid lipofuscinosis resulted in accumulation of mucins in liver-resident macrophages. Our findings suggest that mucin-degrading activity is not limited to the bacterial kingdom and is a component of glycoprotein catabolism in mammalian tissues.
2022-09-03 | PXD027616 | Pride
Project description:Aging is associated with declining immunity and inflammation as well as alterations in the gut microbiome with a decrease of beneficial microbes and increase in pathogenic ones. The aim of this study was to investigate aging associated gut microbiome in relation to immunologic and metabolic profile in a non-human primate (NHP) model. 12 old (age>18 years) and 4 young (age 3-6 years) Rhesus macaques were included in this study. Immune cell subsets were characterized in PBMC by flow cytometry and plasma cytokines levels were determined by bead based multiplex cytokine analysis. Stool samples were collected by ileal loop and investigated for microbiome analysis by shotgun metagenomics. Serum, gut microbial lysate and microbe-free fecal extract were subjected to metabolomic analysis by mass-spectrometry. Our results showed that the old animals exhibited higher inflammatory biomarkers in plasma and lower CD4 T cells with altered distribution of naïve and memory T cell maturation subsets. The gut microbiome in old animals had higher abundance of Archaeal and Proteobacterial species and lower Firmicutes than the young. Significant enrichment of metabolites that contribute to inflammatory and cytotoxic pathways was observed in serum and feces of old animals compared to the young. We conclude that aging NHP undergo immunosenescence and age associated alterations in the gut microbiome that has a distinct metabolic profile.
2022-02-01 | E-MTAB-10160 | biostudies-arrayexpress
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.
2024-06-13 | PXD036037 | Pride
Project description:HuMiChip was used to analyze human oral and gut microbiomes, showing significantly different functional gene profiles between oral and gut microbiome. The results were used to demonstarte the usefulness of applying HuMiChip to human microbiome studies.
2014-02-04 | E-GEOD-54290 | biostudies-arrayexpress
Project description:The inter-organ cross talk between liver and intestine has been focus of intense research. Key in this cross-talk are bile acids, which are secreted from the liver into the intestine and, via the enterohepatic circulation, reach back to the liver. Important new insights have been gained in the Farnesoid X receptor (Fxr)-mediated communication from intestine-to-liver in health and disease. However, liver-to-intestine communication and the role of bile acids and FXR in this cross talk remain elusive. Here, we analyse Fxr-mediated liver-to-gut communication, and its consequences in the colon. Mice in which Fxr was selectively ablated in intestine (Fxr-intKO), the liver (Fxr-livKO), or in the full body (Fxr-totKO) were engineered. The effects on colonic gene expression (RNA sequencing), on the microbiome (16S rRNA Gene Sequencing) and on mucus barrier were analyzed. Compared to Fxr-intKO and Fxr-totKO mice, more genes were differentially expressed in the colons of Fxr-livKO mice relative to control mice (731, 1824 and 3272 respectively), suggestive of a strong role of hepatic Fxr in liver-to-gut communication. The colons of Fxr-livKO showed increased expression of anti-microbial genes, such as Regenerating islet-derived 3 beta and gamma (Reg3β and Reg3γ), Toll-like receptors (Tlrs), inflammasome related genes and differential expression of genes belonging to the ‘Mucin-type O-glycan biosynthesis’ pathway. Compared to control mice, Fxr-livKO mice have decreased levels of the predicted mucin degrading bacterium Turicibacter and a concomitant increase in the thickness of the inner sterile mucus layer. In conclusion, ablation of Fxr in the liver has a major effect on colonic gene expression, the gut microbiome and on the permeability of the mucus layer. This stresses the importance of the Fxr-mediated liver-to-gut signaling.
2021-09-29 | GSE163157 | GEO
Project description:Akkermansia muciniphila, a mucin-degrading microbe found in the human gut, is often associated with positive health outcomes. The abundance of Akkermansia muciniphila is modulated by the presence and accessibility of nutrients, which can be derived from diet or host glycoproteins. In particular, the ability to degrade host mucins, a class of proteins carrying densely O-glycosylated domains, provides a competitive advantage in the sustained colonization of niche mucosal environments. Although Akkermansia muciniphila is known to rely on mucins as a carbon and nitrogen source, the enzymatic machinery used by this microbe to process mucins in the gut is not yet fully characterized. Here, we focus on the mucin-selective metalloprotease, Amuc_0627 (AM0627), which is known to cleave between adjacent residues carrying truncated core 1 O-glycans. We showed that this enzyme is capable of degrading purified mucin 2 (MUC2), the major protein component of mucus in the gut. An X-ray crystal structure of AM0627 (1.9 Å resolution) revealed O-glycan binding residues that are conserved between structurally characterized enzymes from the same family. We further rationalized the substrate cleavage motif using molecular modeling to identify nonconserved glycan-interacting residues. Mutagenesis of these residues resulted in altered substrate preferences down to the glycan level, providing insight into the structural determinants of O-glycan recognition.
2022-06-09 | PXD032164 | Pride
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.
2024-06-13 | PXD035981 | Pride