Molecules derived from cinnamon have demonstrated diverse pharmacological activities against infectious pathogens, diabetes and inflammatory diseases. This study aims to evaluate the effect of the cinnamon-derived molecule IND02 on the adhesion of leukocytes to host cells. The anti-inflammatory ability of IND02, a pentameric procyanidin type A polyphenol polymer isolated from cinnamon alcohol extract, was examined. Pretreatment with IND02 significantly reduced the attachment of THP-1 cells or neutrophils to TNF-α-activated HUVECs or E-selectin/ICAM-1, respectively. IND02 also reduced the binding of E-, L- and P-selectins with sialosides. Furthermore, IND02 could agglutinate human red blood cells (RBC), and the agglutination could be disrupted by sialylated glycoprotein. Our findings demonstrate that IND02, a cinnamon-derived compound, can interact with sialosides and block the binding of selectins and leukocytes with sialic acids.
Glycosylation is a protein post translational modification which plays important role in protein function, stabilization, trafficking, and turnover. Alteration of protein glycosylation is a common phenomenon during tumor progression, migration, invasion, angiogenesis, as well as metastasis. Hence, aberrant glycan structures and the induced corresponding anti-carbohydrate antibodies are potential biomarkers for cancer diagnosis. In this study, serum N-glycomes and anti-carbohydrate antibodies from normal populations and oral squamous cell carcinoma (OSCC) patients were investigated. Total serum proteins were lyophilized and subjected to chemical reduction, alkylation and trypsin digestion. The N-glycans were released, purified, permethylated, and analyzed using MALDI-TOF-Mass spectrometry. In addition, the serum anti-carbohydrate antibody profiles were also investigated by carbohydrate microarray. We found that the relative abundances of seven N-glycans were decreased or increased in serum of OSCC with diagnostic accuracy greater than 75%. The relative abundances of total tri-antennary and tetra-antennary glycans with varying degrees of fucosylation and sialylation were also increased in serum N-glycomes of OSCC. In an independent validation group of forty-eight OCCC patients, most of the high-molecular weight serum N-glycans showed significantly high sensitivity and specificity according to the identified cutoff values. Furthermore, the serum levels of two IgM antibodies were elevated accompanied with the decreased levels of nine IgG antibodies in patient serum. Taken together, these serum N-glycans and antibodies identified in this study should be considered as the candidates of potential biomarkers for OSCC diagnosis.
Partially acetylated chito-oligosaccharides (paCOSs) are bioactive compounds with potential medical applications. Their biological activities are largely dependent on their structural properties, in particular their degree of polymerization (DP) and the position of the acetyl groups along the glycan chain. The production of structurally defined paCOSs in a purified form is highly desirable to better understand the structure/bioactivity relationship of these oligosaccharides. Here, we describe a newly discovered chitinase from Paenibacillus pabuli ( Pp Chi) and demonstrate by mass spectrometry that it essentially produces paCOSs with a DP of three and four that carry a single N- acetylation at their reducing end. We propose that this specific composition of glucosamine (GlcN) and N -acetylglucosamine (GlcNAc) residues, as in GlcN ( n ) GlcNAc 1 , is due to a subsite specificity toward GlcN residues at the −2, −3, and −4 positions of the partially acetylated chitosan substrates. In addition, the enzyme is stable, as evidenced by its long shelf life, and active over a large temperature range, which is of high interest for potential use in industrial processes. It exhibits a k cat of 67.2 s –1 on partially acetylated chitosan substrates. When Pp Chi was used in combination with a recently discovered fungal auxilary activity (AA11) oxidase, a sixfold increase in the release of oligosaccharides from the lobster shell was measured. Pp Chi represents an attractive biocatalyst for the green production of highly valuable paCOSs with a well-defined structure and the expansion of the relatively small library of chito-oligosaccharides currently available.
Aims: The outbreak of highly pathogenic avian influenza H5N1 in poultry and the influenza A pandemic have wreaked havoc on public health. Viruses alter their carbohydrate binding preferences, thereby causing pandemics all over the world. In this study, we tried to investigate the carbohydrate binding specificity of influenza clinical isolates. Materials & methods: Biotin-conjugated polyacrylamide-based glycan epitopes were immobilized on UltraBind™ membranes and used to survey the glycan-binding preference of influenza clinical isolates, including seasonal influenza A, A(H1N1)pdm09 and influenza B viruses. In addition, the DNA sequences of influenza B virus hemagglutinin were analyzed. Results: Human influenza A, especially the A(H1N1)pdm09 viruses, accepted α2,6 and α2,3 sialylated glycans, sulfated glycans and α2,8 sialosides. Although all influenza B clinical isolates bound strongly to NeuAc, 6´-sialyl lactose and sialyl biantennary N-glycan, some viruses also recognized sulfated and α2,3 sialylated glycans. According to the nucleotide sequences of viral hemagglutinin, influenza B viruses that exhibited weak interaction with sulfated and α2,3 sialylated glycans showed fewer charged amino acids. Conclusion: The substrate specificities of influenza clinical isolates were surveyed. Influenza A exhibited more complicated glycan-binding patterns than influenza B viruses. Our findings provided a systematic investigation of receptor-binding specificities for influenza clinical isolates, as well as useful information for exploring viral tropism.
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