Disease relevance of D-xylose

• This paper describes the functional characterization of the xyloside transporter, XylP, of Lactobacillus pentosus with the aid of a spectroscopy-based assay system [1].
• This novel oligosaccharide accounts for 45-65% of xyloside-based products made by both human melanoma and Chinese hamster ovary cells when they are incubated with 30 microM Xyl beta MU, but at 1 mM both the total amount and the proportion decreases to only 5-10% [2].
• However, in neuroblastoma cell line MR23, no low molecular weight xyloside products were made and glycolipid synthesis was not inhibited [3].
• Xyloside-induced disruption of interphotoreceptor matrix proteoglycans results in retinal detachment [4].
• Treatment with the xyloside reduced the average tumor load by 70-97% in SCID mice [5].

High impact information on D-xylose

• Endothelial cell adhesion and migration on fibrinogen were inhibited by both beta-d xyloside and after cleavage of chondroitin sulfate from the core protein by chondroitinase ABC [6].
• First, a xyloside was used to inhibit proteoglycan biosynthesis; second, a variant of the AtT-20 cell line was isolated that synthesized little of the sulfated proteoglycan [7].
• These data indicate that xyloside induces a dramatic imbalance in the de novo-synthesized PGs of cellular and extracellular compartments and that cellular accumulation of xylosylated (sulfated) PGs selectively alters the Golgi apparatus of the glomerular epithelial cell, the cell that actively synthesizes PGs [8].
• In addition, focal alterations in collagen fibril packing, and a disruption of lamellar organization were observed in beta-D xyloside-treated corneas [9].
• Corneal stromas were studied using histochemistry and electron microscopy after in ovo treatment with beta-D xyloside [9].

Chemical compound and disease context of D-xylose

• Glucoside and xyloside conjugates are also major components, regardless of the types of gallstones present, accounting for as much as 18 to 25% [10].

Biological context of D-xylose

• By contrast, the expression of 35S-macromolecules by cells cultured at high cell density for 5 days could be increased by xyloside treatment almost to the same level as that observed in the low density cultures [11].
• Dependence of sea urchin primary mesenchyme cell migration on xyloside- and sulfate-sensitive cell surface-associated components [12].
• In contrast to previous reports, xyloside was found to inhibit hematopoietic cell growth in LTBMC [13].
• Xyloside effects on in vitro hematopoiesis: functional and biochemical studies [13].
• The discrepancy in size but identify of sulfation indicates that, although sulfation takes place normally on either the core protein or the xyloside acceptor, termination of glycosylation occurs earlier for xyloside-initiated chondroitin sulfate [14].

Anatomical context of D-xylose

• The proteoglycans synthesized by cells in a culture maintained on xyloside until Day 8, and then switched to medium with no xyloside 1 h prior to labeling, were characteristic of those synthesized by normal mature Day 8 chondrocytes [15].
• Recognition of influenza virus-infected cells by class II-restricted, virus-specific cytotoxic T lymphocytes was not diminished by the presence of xyloside in the effector phase of the cytotoxicity assay [16].
• We have used isolated rat liver Golgi membranes to reconstitute the synthesis of sulfated glycosaminoglycans (GAGs) onto the membrane-permeable, external acceptor xyloside [17].
• While over 60% of the 35S-labeled material from the blastocoel of normal mesenchyme blastulae is voided from a Sepharose CL-2B column run in a dissociative solvent, only 10% from xyloside treated embryos is voided [18].
• Using [35S]sulfate to label xyloside-initiated GAG chains we find that transport of GAG chains from the trans-Golgi to the cell surface is 15-fold lower in matured oocytes than in immature oocytes [19].

Associations of D-xylose with other chemical compounds

• With the use of a fluorogenic xyloside, 4-methylumbelliferyl-beta-D-xyloside, it was demonstrated that the free chondroitin sulfate chains secreted into the medium bear the xyloside at the reducing end, and have an average molecular weight of 16,500 [20].
• Normal cells were found to migrate on either normal or treated matrix, whereas sulfate-deprived and xyloside-treated PMC failed to migrate in vitro on normal and treated substrata [12].
• The xyloside of [6,7-3H]estrone which was formed by liver microsomes crystallized to constant specific activity with estrone beta-D-xylopyranoside, the chemical preparation of which is described [21].
• The effect of nitrophenyl-beta-D-xyloside (xyloside), a synthetic initiator of glycosaminoglycan synthesis, on proteoglycan and glycosaminoglycan synthesis by a basement membrane producing tumor was studied [22].
• Using of methyl beta-D-[U-14C]xylopyranoside as a very slowly metabolizable inducer of beta-xylanase it has been established that the increase of the rate of xylobiose or methyl xyloside uptake is due to induction of an active transport system for methyl beta-D-xyloside and beta-1,4-xylooligosaccharides [23].

Gene context of D-xylose

• The obligatory involvement of xyloside-primed heparan sulfate in restoration of bFGF-receptor binding was also demonstrated by its sensitivity to heparinase treatment and by the lack of restoration activity in CHO cell mutants that lack enzymatic activities required to form the repeating disaccharide unit characteristic of heparan sulfate [24].
• Treating cultured cells with xyloside, which interferes with glycosaminoglycan attachment to proteoglycans, also completely blocked their ability to incorporate tenascin-C into matrix fibrils [25].
• The mRNA levels for the scavenger receptor A-II and the LDL receptor were not affected by NaClO3 or xyloside treatment [26].
• The xyloside treatment did not reduce the mRNA levels for uPA, indicating that the effect was at the post-translational level [27].
• The binding of 125I-labeled PF4 on treated cells was decreased, and xyloside treatment of cells abrogated the biologic activity of PF4 in a plasma clot culture system [28].

Analytical, diagnostic and therapeutic context of D-xylose

• High performance liquid chromatography and matrix-assisted laser desorption ionization mass spectrometry analysis of intact or glycosidase-digested xyloside showed the structure as: GalNAcalphaGlcAbeta1,3GalNAcbeta1,4GlcAbeta1,3Galbe ta1,3Galbeta1, 4Xylbeta-MU/pNP [29].
• Treatment of both the unstimulated or PMA-stimulated macrophages with xyloside resulted in decreased uPA activity and Western blotting analysis revealed an almost complete absence of secreted uPA protein after xyloside treatment of either control- or PMA-treated cells [27].
• Exposure of cell cultures to rho-nitrophenyl-beta-D xyloside resulted in a 40% decrease in both the amount of 35S-labeled proteoglycan in the cell layer and the 125I-labeled LDL binding, without modifying significantly the cell number and amount of cell layer protein [30].

References