ENHANCED p53-DEPENDENT GROWTH INHIBITION OF HUMAN GLIOBLASTOMA CELLS BY COMBINATORIAL TREATMENT OF TEMOZOLOMIDE AND NOVEL PURIFIED NATURAL CARBOHYDRATE OF PLEUROTUS FLORIDA

Objective: This study was designed to analyze the combinatorial chemotherapeutic effect of temozolomide (TMZ), the most common drug in glioblastoma treatment and a purified carbohydrate (Fr-II) from the edible mushroom Pleurotus florida, on human glioblastoma cell lines.Methods: Fr-II was purified by size-exclusion chromatography and characterised by different mass spectroscopy analysis. Human glioblastoma cells were treated with TMZ, Fr-II, and combination of TMZ and Fr-II. Cell cytotoxicity was measured by MTT assay, cell cycle phase distribution was determined by cell cycle analysis and followed by the relative p53 protein expression was analyzed by western blot analysis.Results: Chemical analysis of Fr-II confirmed the glycosidically linked two units of glucose with terminally attached mannitol with mass of 506 Da. Fr-II treatment exhibited cytotoxicity in both the cell lines in a dose-dependent manner with most effective dose at 200µg/ml. When Fr-II (200µg/ml) was combined with a dose range of TMZ it showed a more cellular cytotoxicity compared to the cytotoxicity of TMZ alone with most oppressive combinatorial dose at 400µM (TMZ)+200µg/ml (Fr-II). In compliance, with the above results, both cell lines showed a 10% increase in no. of cells (p<0.05) in G2/M phase indicating an arrest of cell cycle and increased p53 protein expression (p<0.05) at the combinatorial dose than TMZ alone at 400µM, but Fr-II alone didn't show any cell cycle arrest nor did it show increased p53 expression.Conclusion: Therefore it confirms that Fr-II synergizes with TMZ to significantly intensify its anti-proliferative properties, thereby emerging as an effective element for combinatorial treatment of glioblastoma

Structural characterization of the <i style="">O</i>-antigenic polysaccharide from the lipopolysaccharide of <i style="">Vibrio</i> <i style="">cholerae</i> <i style="">O</i>37

729-734 The chemical structure of the O-antigenic polysaccharide isolated from the lipopolysaccharide of Vibrio cholerae O37 by mild acid hydrolysis was elucidated. The O-antigenic polysac­charide is found to consist of D-glucose, N-acetyl-D-Quinovos­amine and small amount of 4-O-methyl-N-acetyl-D-quinovas­amine. The structure of the O-antigen is established by using sugar and methylation analyses, Smith degradation studies and by using GLC, GC-MS, FAB-MS, one dimensional 1H and 13C NMR spectroscopy and two dimensional NMR spectroscopy including COSY, TOCSY, HSQC, experiments. </smarttagtype

Comparison of lipopolysaccharides composition of two different strains of Helicobacter pylori

BackgroundHelicobacter pylori (H. pylori) is a Gram-negative, microaerophilic bacterium that is recognized as a major cause of chronic gastritis, peptic ulcers, and gastric cancer. Comparable to other Gram-negative bacteria, lipopolysaccharides (LPS) are an important cellular component of the outer membrane of H. pylori. The LPS of this organism plays a key role in its colonization and persistence in the stomach. In addition, H. pylori LPS modulates pathogen-induced host inflammatory responses resulting in chronic inflammation within the gastrointestinal tract. Very little is known about the comparative LPS compositions of different strains of H. pylori with varied degree of virulence in human. Therefore, LPS was analyzed from two strains of H. pylori with differing potency in inducing inflammatory responses (SS1 and G27). LPS were extracted from aqueous and phenol layer of hot-phenol water extraction method and subjected for composition analysis by gas chromatography - mass spectrometry (GC-MS) to sugar and fatty acid compositions.ResultsThe major difference between the two strains of H. pylori is the presence of Rhamnose, Fucose and GalNAc in the SS1 strain, which was either not found or with low abundance in the G27 strain. On the other hand, high amount of Mannose was present in G27 in comparison to SS1. Fatty acid composition of lipid-A portion also showed considerable amount of differences between the two strains, phenol layer of SS1 had enhanced amount of 3 hydroxy decanoic acid (3-OH-C10:0) and 3-hydroxy dodecanoic acid (3-OH-C12:0) which were not present in G27, whereas myristic acid (C14:0) was present in G27 in relatively high amount.ConclusionThe composition analysis of H. pylori LPS, revealed differences in sugars and fatty acids composition between a mouse adapted strain SS1 and G27. This knowledge provides a novel way to dissect out their importance in host-pathogen interaction in further studies

Roles of 3-Deoxy-d-manno-2-Octulosonic Acid Transferase from Moraxella catarrhalis in Lipooligosaccharide Biosynthesis and Virulence

Lipooligosaccharide (LOS), a major outer membrane component of Moraxella catarrhalis, is a possible virulence factor in the pathogenesis of human infections caused by the organism. However, information about the roles of the oligosaccharide chain from LOS in bacterial infection remains limited. Here, a kdtA gene encoding 3-deoxy-d-manno-2-octulosonic acid (Kdo) transferase, which is responsible for adding Kdo residues to the lipid A portion of the LOS, was identified by transposon mutagenesis and construction of an isogenic kdtA mutant in strain O35E. The resulting O35EkdtA mutant produced only lipid A without any core oligosaccharide, and it was viable. Physicochemical and biological analysis revealed that the mutant was susceptible to hydrophobic reagents and a hydrophilic glycopeptide and was sensitive to bactericidal activity of normal human serum. Importantly, the mutant showed decreased toxicity by the Limulus amebocyte lysate assay, reduced adherence to human epithelial cells, and enhanced clearance in lungs and nasopharynx in a mouse aerosol challenge model. These data suggest that the oligosaccharide moiety of the LOS is important for the biological activity of the LOS and the virulence capability of the bacteria in vitro and in vivo. This study may bring new insights into novel vaccines or therapeutic interventions against M. catarrhalis infections

Sialylation Facilitates the Maturation of Mammalian Sperm and Affects Its Survival in Female Uterus.

Establishment of adequate levels of sialylation is crucial for sperm survival and function after insemination; however, the mechanism for the addition of the sperm sialome has not been identified. Here, we report evidence for several different mechanisms that contribute to the establishment of the mature sperm sialome. Directly quantifying the source of the nucleotide sugar CMP-beta-N-acetylneuraminic acid in epididymal fluid indicates that transsialylation occurs in the upper epididymis. Western blots for the low-molecular-mass sialoglycoprotein (around 20-50 kDa) in C57BL/6 mice epididymal fluid reflect that additional sialome could be obtained by glycosylphosphatidylinositol-anchored sialoglycopeptide incorporation during epididymal transit in the caput of the epididymis. Additionally, we found that in Cmah (CMP-N-acetylneuraminic acid hydroxylase)-/- transgenic mice, epididymal sperm obtained sialylated-CD52 from seminal vesicle fluid (SVF). Finally, we used Gfp (green fluorescent protein)+/+ mouse sperm to test the role of sialylation on sperm for protection from female leukocyte attack. There is very low phagocytosis of the epididymal sperm when compared to that of sperm coincubated with SVF. Treating sperm with Arthrobacter ureafaciens sialidase (AUS) increased phagocytosis even further. Our results highlight the different mechanisms of increasing sialylation, which lead to the formation of the mature sperm sialome, as well as reveal the sialome's function in sperm survival within the female genital tract

Sialylation Facilitates the Maturation of Mammalian Sperm and Affects Its Survival in Female Uterus.

Establishment of adequate levels of sialylation is crucial for sperm survival and function after insemination; however, the mechanism for the addition of the sperm sialome has not been identified. Here, we report evidence for several different mechanisms that contribute to the establishment of the mature sperm sialome. Directly quantifying the source of the nucleotide sugar CMP-beta-N-acetylneuraminic acid in epididymal fluid indicates that transsialylation occurs in the upper epididymis. Western blots for the low-molecular-mass sialoglycoprotein (around 20-50 kDa) in C57BL/6 mice epididymal fluid reflect that additional sialome could be obtained by glycosylphosphatidylinositol-anchored sialoglycopeptide incorporation during epididymal transit in the caput of the epididymis. Additionally, we found that in Cmah (CMP-N-acetylneuraminic acid hydroxylase)-/- transgenic mice, epididymal sperm obtained sialylated-CD52 from seminal vesicle fluid (SVF). Finally, we used Gfp (green fluorescent protein)+/+ mouse sperm to test the role of sialylation on sperm for protection from female leukocyte attack. There is very low phagocytosis of the epididymal sperm when compared to that of sperm coincubated with SVF. Treating sperm with Arthrobacter ureafaciens sialidase (AUS) increased phagocytosis even further. Our results highlight the different mechanisms of increasing sialylation, which lead to the formation of the mature sperm sialome, as well as reveal the sialome's function in sperm survival within the female genital tract

Activation of Parathyroid Hormone 2 Receptor Induces Decorin Expression and&nbsp;Promotes Wound Repair.

In this study, we report that TIP39, a parathyroid hormone ligand family member that was recently identified to be expressed in the skin, can induce decorin expression and enhance wound repair. Topical treatment of mice with TIP39 accelerated wound repair, whereas TIP39-deficient mice had delayed repair that was associated with formation of abnormal collagen bundles. To study the potential mechanism responsible for the action of TIP39 in the dermis, fibroblasts were cultured in three-dimensional collagen gels, a process that results in enhanced decorin expression unless activated to differentiate to adipocytes, whereupon these cells reduce expression of several proteoglycans, including decorin. Small interfering RNA-mediated silencing of parathyroid hormone 2 receptor (PTH2R), the receptor for TIP39, suppressed the expression of extracellular matrix-related genes, including decorin, collagens, fibronectin, and matrix metalloproteases. Skin wounds in TIP39-/- mice had decreased decorin expression, and addition of TIP39 to cultured fibroblasts induced decorin and increased phosphorylation and nuclear translocation of CREB. Fibroblasts differentiated to adipocytes and treated with TIP39 also showed increased decorin and production of chondroitin sulfate. Furthermore, the skin of PTH2R-/- mice showed abnormal extracellular matrix structure, decreased decorin expression, and skin hardness. Thus, the TIP39-PTH2R system appears to be a previously unrecognized mechanism for regulation of extracellular matrix formation and wound repair