NMR metabolomics reveals effects of Cryptosporidium infections on host cell metabolome

Background: Cryptosporidium is an important gut microbe whose contributions towards infant and immunocompromise patient mortality rates are steadily increasing. Over the last decade, we have seen the development of various tools and methods for studying Cryptosporidium infection and its interactions with their hosts. One area that is sorely overlooked is the effect infection has on host metabolic processes. Results: Using a 1H nuclear magnetic resonance approach to metabolomics, we have explored the nature of the mouse gut metabolome as well as providing the first insight into the metabolome of an infected cell line. Statistical analysis and predictive modelling demonstrated new understandings of the effects of a Cryptosporidium infection, while verifying the presence of known metabolic changes. Of note is the potential contribution of host derived taurine to the diarrhoeal aspects of the disease previously attributed to a solely parasite-based alteration of the gut environment, in addition to other metabolites involved with host cell catabolism. Conclusion: This approach will spearhead our understanding of the Cryptosporidium-host metabolic exchange and provide novel targets for tackling this deadly parasite

Metabolic changes of the host-pathogen environment in a Cryptosporidium infection

Cryptosporidium is an important gut microbe whose contributions towards infant and immunocompromise patient mortality rates are steadily increasing. Current techniques for diagnosing, curing or simply understanding the biology of the parasite are few and far between, relying on a combination of in-silico predictions modelled on a varied and unique group of organisms and medical reports. The development of an in-vitro culture system, using COLO-680N cells, has provided the Cryptosporidium community with the opportunity to expand its toolkit for investigating this disease. One area in particular that is sorely overlooked is the metabolic alterations upon infection. Existing research is extremely limited and has already shown that significant variation can be found between the metabolome of different infected host species. Using a 1H Nuclear Magnetic Resonance approach to metabolomics, we have explored the nature of the mouse gut metabolome as well as providing the first insight into the metabolome of an infected cell line. Through a combination of Partial Least Squares Discriminant Analysis and predictive modelling, we exhibit new and potentially game changing insights into the effects of a Cryptosporidium parvum infection, while verifying the presence of known metabolic changes. Of particular note is the potential contribution of host derived taurine to the diuretic aspects of the disease previously attributed to a solely parasite based alteration of the gut environment. This practical and informative approach can spearhead our understanding of the Cryptosporidium-host metabolic exchange and thus provide novel targets for tackling this deadly parasite

Fucosylated chondroitin sulfates from the body wall of the sea cucumberholothuria forskali

Fucosylated chondroitin sulfate (fCS) extracted from the sea cucumber Holothuria forskali is composed of the following repeating trisaccharide unit: -> 3)GalNAc beta 4,6S(1 -> 4) [Fuc alpha X(1 -> 3)]GlcA beta(1 ->, where X stands for different sulfation patterns of fucose (X = 3,4S (46%), 2,4S (39%), and 4S (15%)). As revealed by NMR and molecular dynamics simulations, the fCS repeating unit adopts a conformation similar to that of the Le(x) blood group determinant, bringing several sulfate groups into close proximity and creating large negative patches distributed along the helical skeleton of the CS backbone. This may explain the high affinity of fCS oligosaccharides for L-and P-selectins as determined by microarray binding of fCS oligosaccharides prepared by Cu2+-catalyzed Fenton-type and photochemical depolymerization. No binding to E-selectin was observed. fCS poly- and oligosaccharides display low cytotoxicity in vitro, inhibit human neutrophil elastase activity, and inhibit the migration of neutrophils through an endothelial cell layer in vitro. Although the polysaccharide showed some anti-coagulant activity, small oligosaccharide fCS fragments had much reduced anticoagulant properties, with activity mainly via heparin cofactor II. The fCS polysaccharides showed prekallikrein activation comparable with dextran sulfate, whereas the fCS oligosaccharides caused almost no effect. The H. forskali fCS oligosaccharides were also tested in a mouse peritoneal inflammation model, where they caused a reduction in neutrophil infiltration. Overall, the data presented support the action of fCS as an inhibitor of selectin interactions, which play vital roles in inflammation and metastasis progression. Future studies of fCS-selectin interaction using fCS fragments or their mimetics may open new avenues for therapeutic intervention