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European Journal of Clinical... Oct 2019The aim of this study was to investigate the effects that prebiotic and candidates for prebiotics on Clostridium difficile strains to adhere to various human epithelial...
The aim of this study was to investigate the effects that prebiotic and candidates for prebiotics on Clostridium difficile strains to adhere to various human epithelial cell lines and to compare the adhesive properties of specific C. difficile strains. We also sought to examine the effect of different concentrations of fructooligosaccharides and mannose on the formation of biofilms by C. difficile strains. The influence of cellobiose, fructooligosaccharides, inulin, mannose, and raffinose on the adherence properties of various C. difficile strains, including motile 630, non-motile M120, and 10 clinical motile ribotype 027 strains, to non-mucous secreting HT-29, mucous secreting HT-29 MXT, and CCD 841 CoN cells lines. The most effective prebiotics were used in biofilm formation assays. We demonstrated that all C. difficile strains adhered to all cell lines. However, the C. difficile M120 non-motile strain was statistically more likely to adhere to all three cell lines (CFU median, 40) compared to the motile strains (CFU median, 3; p < 0.001). Furthermore, among the carbohydrates examined, only fructooligosaccharides and mannose were found to significantly decrease adhesion (p < 0.001) of C. difficile strains. Alternatively, using a biofilm assay, we observed, via confocal laser scanning microscopy, that sub-inhibitory concentrations (1%) of fructooligosaccharides and mannose functioned to increase biofilm formation by C. difficile. We demonstrated that specific prebiotics and candidate prebiotics exhibit varying anti-adhesive properties towards C. difficile in vitro and that treatment with sub-inhibitory concentrations of prebiotics can cause an increase in biofilm formation by C. difficile.
Topics: Anti-Bacterial Agents; Bacterial Adhesion; Biofilms; Cell Line; Clostridioides difficile; Epithelial Cells; Humans; Locomotion; Mannose; Oligosaccharides; Prebiotics
PubMed: 31363870
DOI: 10.1007/s10096-019-03635-7 -
Angewandte Chemie (International Ed. in... Jul 2018O-Mannose glycans account up to 30 % of total O-glycans in the brain. Previous synthesis and functional studies have only focused on the core M3 O-mannose glycans of...
O-Mannose glycans account up to 30 % of total O-glycans in the brain. Previous synthesis and functional studies have only focused on the core M3 O-mannose glycans of α-dystroglycan, which are a causative factor for various muscular diseases. In this study, a highly efficient chemoenzymatic strategy was developed that enabled the first collective synthesis of 63 core M1 and core M2 O-mannose glycans. This chemoenzymatic strategy features the gram-scale chemical synthesis of five judiciously designed core structures, and the diversity-oriented modification of the core structures with three enzyme modules to provide 58 complex O-mannose glycans in a linear sequence that does not exceed four steps. The binding profiles of synthetic O-mannose glycans with a panel of lectins, antibodies, and brain proteins were also explored by using a printed O-mannose glycan array.
Topics: Animals; Biocatalysis; Chemistry Techniques, Synthetic; Dystroglycans; Glycosylation; Glycosyltransferases; Humans; Mannose; Polysaccharides
PubMed: 29802667
DOI: 10.1002/anie.201804373 -
Clinical importance of high-mannose, fucosylated, and complex N-glycans in breast cancer metastasis.JCI Insight Dec 2021Although aberrant glycosylation is recognized as a hallmark of cancer, glycosylation in clinical breast cancer (BC) metastasis has not yet been studied. While...
BACKGROUND
Although aberrant glycosylation is recognized as a hallmark of cancer, glycosylation in clinical breast cancer (BC) metastasis has not yet been studied. While preclinical studies show that the glycocalyx coating of cancer cells is involved in adhesion, migration, and metastasis, glycosylation changes from primary tumor (PT) to various metastatic sites remain unknown in patients.
METHODS
We investigated N-glycosylation profiles in 17 metastatic BC patients from our rapid autopsy program. Primary breast tumor, lymph node metastases, multiple systemic metastases, and various normal tissue cores from each patient were arranged on unique single-patient tissue microarrays (TMAs). We performed mass spectrometry imaging (MSI) combined with extensive pathology annotation of these TMAs, and this process enabled spatially differentiated cell-based analysis of N-glycosylation patterns in metastatic BC.
RESULTS
N-glycan abundance increased during metastatic progression independently of BC subtype and treatment regimen, with high-mannose glycans most frequently elevated in BC metastases, followed by fucosylated and complex glycans. Bone metastasis, however, displayed increased core-fucosylation and decreased high-mannose glycans. Consistently, N-glycosylated proteins and N-glycan biosynthesis genes were differentially expressed during metastatic BC progression, with reduced expression of mannose-trimming enzymes and with elevated EpCAM, N-glycan branching, and sialyation enzymes in BC metastases versus PT.
CONCLUSION
We show in patients that N-glycosylation of breast cancer cells undergoing metastasis occurs in a metastatic site-specific manner, supporting the clinical importance of high-mannose, fucosylated, and complex N-glycans as future diagnostic markers and therapeutic targets in metastatic BC.
FUNDING
NIH grants R01CA213428, R01CA213492, R01CA264901, T32CA193145, Dutch Province Limburg "LINK", European Union ERA-NET TRANSCAN2-643638.
Topics: Adult; Aged; Breast Neoplasms; Female; Glycosylation; Humans; Mannose; Middle Aged; Neoplasm Metastasis; Polysaccharides
PubMed: 34752419
DOI: 10.1172/jci.insight.146945 -
Molecular Immunology Oct 2023Vacuolar-type H-ATPase (V-ATPase) critically controls phagosome acidification to promote pathogen digestion and clearance in macrophage. However, the specific subunits...
Vacuolar-type H-ATPase (V-ATPase) critically controls phagosome acidification to promote pathogen digestion and clearance in macrophage. However, the specific subunits of V-ATPase have been evidenced to play contradictory functions in inflammatory cytokines generation and secretion exposure to external bacterial or LPS stimulation. Therefore, identifying the unique function of the separate subunit of V-ATPase is extremely important to regulate macrophage function. Here, we found that D-mannose, a C-2 epimer of glucose, suppressed ATP6V1B2 lysosomal translocation to inhibit V-ATPase activity in macrophages, thereby causing the scaffold protein axis inhibitor protein (AXIN) recruitment to lysosomal membrane and AMPK activation. Correspondingly, LPS-stimulated macrophage M1 polarization was significantly suppressed by D-mannose via down-regulating NF-κB signaling pathway in response to AMPK activation, while IL-4 induced macrophage M2 polarization were not affected. Furthermore, the failure of lysosomal localization of ATP6V1B2 caused by D-mannose also led to the acidification defects of lysosome. Therefore, D-mannose displayed a remarkable function in inhibiting macrophage phagocytosis and bacterial killing. Taken together, D-mannose acts a novel V-ATPase suppressor to attenuate macrophage inflammatory production but simultaneously prevent macrophage phagocytosis and bacterial killing.
Topics: Adenosine Triphosphatases; Cytokines; Mannose; AMP-Activated Protein Kinases; Lipopolysaccharides; Macrophages
PubMed: 37660434
DOI: 10.1016/j.molimm.2023.08.013 -
Neurochemistry International Jul 2022Temozolomide (TMZ) is generally applied for glioma treatment, while drug resistance of TMZ limits its therapeutic efficacy. Mannose exerts evident anti-tumor effect. We...
BACKGROUND
Temozolomide (TMZ) is generally applied for glioma treatment, while drug resistance of TMZ limits its therapeutic efficacy. Mannose exerts evident anti-tumor effect. We intended to investigate whether mannose enhanced TMZ sensitivity to glioma and examined the underlying mechanism.
METHODS
MTT and clone formation assays were performed to detect cell viability and proliferation. Cell apoptosis was measured by flow cytometry. The protein and gene expression levels were detected by Western blot and qRT-PCR assays. Xenograft glioma model was established to explore the influence of mannose in vivo.
RESULTS
Mannose inhibited glioma cell growth, which was facilitated by knockdown of phosphomannose isomerase (PMI) while reversed by overexpression of PMI. Mannose enhanced the sensitivity of glioma cells to TMZ, indicated by the further inhibited cell viability and colony formation and the aggravated cell apoptosis, which was reversed by overexpression of O6-methylguanine DNA methyltransferase (MGMT). Furthermore, mannose and TMZ inhibited MGMT expression and Wnt/β-catenin activation. Moreover, activating Wnt/β-catenin pathway blocked anti-proliferative effect induced by mannose and TMZ, which was further suppressed by overexpressed MGMT. Mannose inhibited glioma growth, suppressed Ki67 and downregulated MGMT and β-catenin in vivo.
CONCLUSION
Mannose inhibited MGMT to enhance sensitivity of glioma cells to TMZ, with Wnt/β-catenin pathway involvement. Our data suggested that mannose could be an innovative agent to improve glioma treatment, particularly in TMZ-resistant glioma with high MGMT.
Topics: Apoptosis; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Glioma; Humans; Mannose; O(6)-Methylguanine-DNA Methyltransferase; Temozolomide; Wnt Signaling Pathway; beta Catenin
PubMed: 35490896
DOI: 10.1016/j.neuint.2022.105348 -
International Journal of Biological... Dec 2022Because of the apparent stasis in antibiotic discoveries and the growth of multidrug resistance, Helicobacter pylori-associated gastric infections are difficult to...
Because of the apparent stasis in antibiotic discoveries and the growth of multidrug resistance, Helicobacter pylori-associated gastric infections are difficult to eradicate. In the search for alternative therapy, the reductive amination of chitosan with mannose, followed by ionic gelation, produced mannose functionalized chitosan nanoparticles. Then, molecular docking and molecular dynamics (MD) simulations were conducted with H. pylori lectin (HPLectin) as a target protein involved in bacterium adherence to host cells, biofilm formation, and cytotoxicity. Changes in zeta potential and FTIR spectroscopy revealed that chitosan was functionalized with mannose. Time-kill, polystyrene adherence, and antibiofilm studies were utilized to assess nanoparticles as an alternative antibacterial treatment against a resistant gastric pathogen. Man-CS-Nps were discovered to have effective anti-adherence and biofilm disruption characteristics in suppressing the development of resistant H. pylori. In addition, bioimaging studies with CLSM, TEM, and SEM illustrated that Man-CS-Nps interacted with bacterial cells and induced membrane disruption by creating holes in the outer membranes of the bacterial cells, resulting in the leakage of amino acids. Importantly, molecular docking and 20 ns MD simulations revealed that Man-CS-Nps inhibited the target protein through slow-binding inhibition and hydrogen bond interactions with active site residues. As a consequence of the findings of this study, the Man-CS-Nps is an excellent candidate for developing alternative therapies for the increasing incidences of resistant gastric infections.
Topics: Humans; Chitosan; Helicobacter pylori; Mannose; Molecular Docking Simulation; Nanoparticles; Anti-Bacterial Agents; Helicobacter Infections
PubMed: 36356866
DOI: 10.1016/j.ijbiomac.2022.10.265 -
Frontiers in Immunology 2022D-mannose can be transported into a variety of cells glucose transporter (GLUT), and supraphysiological levels of D-mannose impairs tumor growth and modulates immune...
D-mannose can be transported into a variety of cells glucose transporter (GLUT), and supraphysiological levels of D-mannose impairs tumor growth and modulates immune cell function through mechanisms such as interference with glycolysis and induction of oxidative stress. Blood-stage mainly depends on glycolysis for energy supply and pathological immune response plays a vital role in cerebral malaria. However, it is not clear whether mannose affects malaria blood-stage infection. Here, we fed D-mannose to -infected mice and found weight loss and reduced parasitemia without apparent side effects. Compromised parasitemia in C57BL/6 mice was accompanied by an increase in splenic macrophages compared to an untreated group. When mannose was applied to a rodent experimental cerebral malaria (ECM) model, the incidence of ECM decreased. Expression of activation marker CD69 on T cells in peripheral blood and the brain were reduced, and cerebral migration of activated T cells was prevented by decreased expression of CXCR3. These findings suggest that mannose inhibits infection by regulating multiple host immune responses and could serve as a potential strategy for facilitating malaria treatment.
Topics: Animals; Glucose Transport Proteins, Facilitative; Immunity; Malaria, Cerebral; Mannose; Mice; Mice, Inbred C57BL; Parasitemia; Parasites; Plasmodium berghei
PubMed: 36211381
DOI: 10.3389/fimmu.2022.859228 -
Structural Basis of the Mechanisms of Action and Immunity of Lactococcin A, a Class IId Bacteriocin.Applied and Environmental Microbiology Mar 2023Lactococcin A (LcnA), a class IId bacteriocin, induces membrane leakage and cell death by specifically binding to the membrane receptor-mannose phosphotransferase system...
Lactococcin A (LcnA), a class IId bacteriocin, induces membrane leakage and cell death by specifically binding to the membrane receptor-mannose phosphotransferase system (man-PTS), as is the case for pediocin-like (class IIa) bacteriocins. The cognate immunity protein of bacteriocins, which protects the producer cell from its own bacteriocin, recognizes and binds to the bacteriocin-man-PTS complex, consequently blocking membrane leakage. We previously deciphered the mode of action and immunity of class IIa bacteriocins. Here, we determined the structure of the ternary complex of LcnA, LciA (, the immunity protein), and its receptor, , the man-PTS of Lactococcus lactis (ll-man-PTS). An external loop on the membrane-located component IIC of ll-man-PTS was found to prevent specific binding of the N-terminal region of LcnA to the site recognized by pediocin-like bacteriocins. Thus, the N-terminal β-sheet region of LcnA recognized an adjacent site on the extracellular side of ll-man-PTS, with the LcnA C-terminal hydrophobic helix penetrating into the membrane. The cytoplasmic cleft formed within the man-PTS Core and Vmotif domains induced by embedded LcnA from the periplasmic side is adopted by the appropriate angle between helices H3 and H4 of the N terminus of LciA. The flexible C terminus of LciA then blocks membrane leakage. To summarize, our findings reveal the molecular mechanisms of action and immunity of LcnA and LciA, laying a foundation for further design of class IId bacteriocins. Class IId (lactococcin-like) bacteriocins and class IIa (pediocin-like) bacteriocins share a few similarities: (i) both induce membrane leakage and cell death by specifically binding the mannose phosphotransferase system (man-PTS) on their target cells, and (ii) cognate immunity proteins recognize and bind to the bacteriocin-man-PTS complex to block membrane leakage. However, class IId bacteriocins lack the "pediocin box" motif, which is typical of class IIa bacteriocins, and basically target only lactococcal cells; in contrast, class IIa bacteriocins target diverse bacterial cells, but not lactococcal cells. We previously solved the structure of class IIa bacteriocin-receptor-immunity ternary complex from Lactobacillus sakei. Here, we determined the structure of the ternary complex of class IId bacteriocin LcnA, its cognate immunity protein LciA, and its receptor, the man-PTS of Lactococcus lactis. By comparing the interactions between man-PTS and class IIa and class IId bacteriocins, this study affords some clues to better understand the specificity of bacteriocins targeting the mannose phosphotransferase system.
Topics: Pediocins; Mannose; Bacteriocins; Lactococcus lactis; Phosphotransferases
PubMed: 36840592
DOI: 10.1128/aem.00066-23 -
Molecules (Basel, Switzerland) Feb 2022Thanks to their ability to bind to specific biological receptors, mannosylated structures are examined in biomedical applications. One of the most common ways of linking...
Thanks to their ability to bind to specific biological receptors, mannosylated structures are examined in biomedical applications. One of the most common ways of linking a functional moiety to a structure is to use an azide-alkyne click reaction. Therefore, it is necessary to prepare and isolate a propargylated mannose derivative of high purity to maintain its bioactivity. Three known preparations of propargyl-α-mannopyranoside were revisited, and products were analysed by NMR spectroscopy. The preparations were shown to yield by-products that have not been described in the literature yet. Our experiments showed that one-step procedures could not provide pure propargyl-α-mannopyranoside, while a three-step procedure yielded the desired compound of high purity.
Topics: Mannose
PubMed: 35268584
DOI: 10.3390/molecules27051483 -
Nature Communications Jul 2017Protein glycosylation is a critical protein modification. In biogenic membranes of eukaryotes and archaea, these reactions require activated mannose in the form of the...
Protein glycosylation is a critical protein modification. In biogenic membranes of eukaryotes and archaea, these reactions require activated mannose in the form of the lipid conjugate dolichylphosphate mannose (Dol-P-Man). The membrane protein dolichylphosphate mannose synthase (DPMS) catalyzes the reaction whereby mannose is transferred from GDP-mannose to the dolichol carrier Dol-P, to yield Dol-P-Man. Failure to produce or utilize Dol-P-Man compromises organism viability, and in humans, several mutations in the human dpm1 gene lead to congenital disorders of glycosylation (CDG). Here, we report three high-resolution crystal structures of archaeal DPMS from Pyrococcus furiosus, in complex with nucleotide, donor, and glycolipid product. The structures offer snapshots along the catalytic cycle, and reveal how lipid binding couples to movements of interface helices, metal binding, and acceptor loop dynamics to control critical events leading to Dol-P-Man synthesis. The structures also rationalize the loss of dolichylphosphate mannose synthase function in dpm1-associated CDG.The generation of glycolipid dolichylphosphate mannose (Dol-P-Man) is a critical step for protein glycosylation and GPI anchor synthesis. Here the authors report the structure of dolichylphosphate mannose synthase in complex with bound nucleotide and donor to provide insight into the mechanism of Dol-P-Man synthesis.
Topics: Amino Acid Sequence; Archaeal Proteins; Binding Sites; Biocatalysis; Crystallography, X-Ray; Mannose; Mannosyltransferases; Models, Molecular; Protein Domains; Pyrococcus furiosus; Recombinant Proteins; Sequence Homology, Amino Acid
PubMed: 28743912
DOI: 10.1038/s41467-017-00187-2