Concentrations Of L-fucose Research Articles

Metabolomics Study of Serum Samples of β-YAC Transgenic Mice Treated with Tenofovir Disoproxil Fumarate.

β-thalassemia is one of the most common monogenic disorders and a life-threatening health issue in children. A cost-effective and safe therapeutic approach to treat this disease is to reactivate the γ-globin gene for fetal hemoglobin (HbF) production that has been silenced during infancy. Hydroxyurea (HU) is the only FDA approved HbF inducer. However, its cytotoxicity and inability to respond significantly in all patients pose a need for an HbF inducer with better efficacy. The study describes the serum metabolic alteration in β-YAC transgenic mice treated with Tenofovir disoproxil fumarate (TDF) (n = 5), a newly identified HbF inducer, and compared to the mice groups treated with HU (n = 5) and untreated control (n = 5) using gas chromatography-mass spectrometry. Various univariate and multivariate statistical analyses were performed to identify discriminant metabolites that altered the biological pathways encompassing galactose metabolism, lactose degradation, and inositol. Furthermore, the decreased concentrations of L-fucose and geraniol in TDF-treated mice help in recovering towards normal, decreasing oxidative stress even much better than the HU-treated mice. The proposed study suggested that TDF can reduce the deficiency of blood required for β-thalassemia and can be used for the preclinical study at phase I/II for fetal hemoglobin production.

Feasibility of Near-Infrared Spectroscopy for Identification of L-Fucose and L-Proline—Towards Detecting Cancer Biomarkers from Saliva

Near-infrared spectroscopy (NIRS) is a non-ionizing optical technique that can be used to quantify proteins, carbohydrates, fats, and other organic and biological substances. The aim of this study was to determine the ability of NIRS to identify different concentrations of L-fucose and L-proline solutions by utilizing different NIR spectral regions. NIR spectra of solid L-fucose and L-proline, their aqueous solutions in different concentrations, and the spectra of saliva samples collected from two patients with oral squamous cell carcinoma (OSCC) were studied. Differences in spectra of the pure solid reference samples and water were most noticeable in spectral regions 800–1250 nm and 1418–1867 nm. The saliva sample with an atypically high concentration of oral cancer biomarkers showed a similar spectral feature between 1530–1650 nm as the liquid samples with cancer biomarkers. In addition, a fine k-nearest neighbors (kNN) classifier was trained to differentiate the aqueous solutions and achieved 75.97% validation accuracy. The preliminary study presents that NIRS can be utilized to detect differences in spectra between the different biomarker concentrations in aqueous solutions. However, the qualitative measures may have resulted in limited sensitivity, which could be enhanced by additional samples and using a measurement probe dedicated to fluid measurements.

An amperometric biosensor of L-fucose in urine for the first screening test of cancer

Quantitative routine detection of fucose, which is a cancer marker, in urine is effective for the preliminary screening of cancer. Amperometric biosensing methods have the advantage of being simple, rapid, and precise for urinalysis. However, coexisting electroactive interferences such as ascorbic acid (AA), dopamine (DA), and uric acid (UA) prevent accurate measurements. In this work, an amperometric l-fucose biosensor unaffected by interferences was developed and utilizes direct electron transfer type bioelectrocatalysis of pyrroloquinoline quinone (PQQ)-dependent pyranose dehydrogenase from Coprinopsis cinerea (CcPDH). The isolated PQQ domain from CcPDH was immobilized on gold nanoparticle (AuNP)-modified electrodes, which obtained a catalytic current at a lower potential than the oxidation potential of the interfering compounds. Applying an operating potential of −0.1 V vs. Ag|AgCl (3 M NaCl) enabled the detection of l-fucose while completely eliminating the oxidation of AA, DA, and UA on the electrodes. The increase in the specific area of the electrodes by increasing the AuNP drop-casting time resulted in an improvement in the sensor performance. The biosensor exhibited a linear range for l-fucose detection between 0.1 mM and 1 mM (R2 = 0.9996), including a cut-off value, the sensitivity was 3.12 ± 0.05 μA mM−1 cm−2, and the detection limit was 13.6 μM at a signal-to-noise ratio of three. The biosensor can be used to quantify the concentration of l-fucose at physiological levels and does not require urine preprocessing, making it applicable to practical use for point-of-care testing with urine.

Evaluation of L-fucose and Sialic Acid Levels in Patients With Colorectal Cancer and Control Subject

Background: Currently, glycans, which are known as functional molecules in the biological system, are being under study as potential cancer markers. This study aimed to determine the level of serum L-fucose and sialic acid as the biomarkers in patients with colorectal cancer (CRC). Materials and Methods: The patients with CRC (n=40, 20 men and 20 women) participated in the present study. The spectrophotometric method was used to measure the levels of L-fucose and sialic acid in the serum of the patients. SPSS (version 21) was used to analyze the obtained data. The results were expressed as mean ± SD. Results: The mean ± SD L-fucose level in patients with CRC was 27.46 ± 4.8 ng/mL, which was more than this level in the healthy control group (18.64±3.1 ng/mL). Also, the mean ± SD serum concentration of sialic acid in patients with CRC was 2.1 ± 0.41 ng/mL, which was more than the mean ± SD sialic acid level of 1.23±0.21 ng/mL in the healthy controls. Conclusion: Serum concentration of L-fucose and sialic acid increased significantly (P < 0.05) in patients with CRC compared with the healthy controls. We believe that determining serum L-fucose and sialic acid levels could be useful for the detection of CRC patients in the early stage.

Synthesis of Fucose-Containing Disaccharides by Glycosylhydrolases from Various Origins.

Glycosylhydrolases of various origins were used to produce fucose-containing disaccharides with prebiotic potential using different donor substrates and L-fucose as the acceptor substrate. Eight different disaccharides were synthesized as follows: three β-D-galactosyl-L-fucosides with glycosidase CloneZyme Gly-001-02 using D-lactose as a donor substrate, two with a structure similar to prebiotics; one β-D-galactosyl-L-fucose with β-D-galactosidase from Aspergillus oryzae using D-lactose as a substrate donor; and four α-D-glucosyl-L-fucosides with α-D-glucosidase from Saccharomyces cerevisiae using D-maltose as a donor substrate. All disaccharides were purified and hydrolyzed. In all cases, an L-fucose moiety was present, and it was confirmed for β-D-galactosyl-L-fucose by mass spectrometry. High concentrations of L-fucose as the acceptor substrate enhanced the synthesis of the oligosaccharides in all cases. The three enzymes were able to synthesize fucose-containing disaccharides when L-fucose was used as the acceptor substrate, and the highest yield was 20% using β-D-galactosidase from Aspergillus oryzae.

Assay of hemoglobin A1c using lectin from Aleuria aurantia.

Hemoglobin A1c (HbA1c) has an N-terminal fructosyl valine on the β-chain, and this modification is caused by the non-enzymatic glycosylation of hemoglobin (Hb). The relative concentration ratio of HbA1c to total Hb is an important biomarker for the diagnosis of diabetes. HbA1c-binding lectins were screened from 29 sources of lectin, and the lectin from Aleuria aurantia (AAL) was revealed to have higher affinity to HbA1c than to Hb. The concentration of HbA1c was determined by lectin-based enzyme-linked immunosorbent assay (ELISA) using the AAL lectin. Higher reproducibility of the assay was observed at 4 °C than at 25 and 37 °C. This observation is consistent with the known temperature-dependent behavior of lectins. Preincubation of HbA1c with an anti-HbA1c antibody inhibited the binding, suggesting that AAL binds to the N-terminal fructosyl valine epitope of HbA1c. Higher inhibitory effect was observed for 10 mM d-fructose than for the same concentrations of l-fucose, d-fucose, or d-glucose.

Growth of Autobioluminescent Campylobacter jejuni in Response to Various Environmental Conditions

An autobioluminescent Campylobacter jejuni organism generated from the fusion of luxCDABE genes from Xenorhabdus luminescens to the flaA promoter of C. jejuni was used in conjunction with gel-stabilized gradient plates to map the responses of this organism to three environmental factors (pH, NaCl concentration, and temperature) and various concentrations of l-fucose, d-fucose, and sodium desoxycholate. The minimum, optimum, and maximum temperatures for the growth of auto-bioluminescent C. jejuni ATCC 35921 in solid media were found to be 30, 40, and 45°C, respectively. At its optimum growth temperature, C. jejuni ATCC 35921 was able to grow well at pHs of 5.5 to 8.0 and in the presence of up to 1.70 to 1.75% NaCl. At its minimum growth temperature, however, C. jejuni ATCC 35921 could grow only at pHs of 6.5 to 8.0 and in the presence of up to 0.5% NaCl. l-Fucose, d-fucose, and sodium desoxycholate were shown to inhibit the growth of C. jejuni. Autobioluminescent C. jejuni was also used to determine whether the flaA promoter responds to both environmental conditions and chemical stimulants. While sodium desoxycholate was found to down-regulate C. jejuniflaA promoter activity, l-fucose was found to up-regulate its activity. Sodium chloride, pH, and d-fucose were all shown to exert no significant effects on promoter activity. Bacterial bioluminescence in combination with two-dimensional gradient gels is a powerful tool for studying the behavior of bacteria exposed to various environments.

Protection by L-fucose and fucose-rich polysaccharides against ROS-produced cell death in presence of ascorbate

It was shown previously, that millimolar concentrations of ascorbate have cytotoxic and anti-proliferative effects (Eur. J. Clin. Invest. 32 (2002) 372). With increasing concentrations of ascorbate an increasing number of fibroblasts was detached from the culture dish and shown to be lysed by the effect of ascorbate-induced generation of reactive oxygen species (ROS-s). It also could be shown, that this cytotoxic effect is partly due to the dose-dependent inhibition by ascorbate of fibronectin biosynthesis. Superoxide dismutase (SOD) and catalase were shown to salvage cells from ROS-induced cell-death by preventing the inhibition of fibronectin biosynthesis. We used this model system to test the cyto-protective effect of L-fucose and fucose-rich oligo- and polysaccharides (FROP-s). It appeared that relatively low concentrations of L-fucose and FROP-3 (Biomed. Pharmacother. in press) could efficiently protect fibroblasts from the ascorbate-induced cell-death. These novel pharmacological properties of L-fucose and FROP-3 might well be related to their accelerating effect of wound healing.

L‐fucose reduces collagen and noncollagen protein production in cultured cerebral microvessel endothelial cells

L-fucose is a monosaccharide which is present in low concentrations in normal serum but is increased in diabetes, cancer, and inflammatory diseases. The contribution that abnormal L-fucose levels make to the progression of these disorders is unknown. In a previous study we showed that increased L-fucose concentration reduced proliferation and proteoglycan production by cultured cerebral microvessel endothelial cells. In the present study we show that exposing cerebral microvessel endothelial cells for 2 weeks to medium containing an increased concentration of L-fucose causes a significant decrease in collagen and to a lesser extent noncollagen protein production. The effect of L-fucose on collagen and noncollagen protein production is concentration-dependent: 1 mM L-fucose causes a significant decrease in collagen production but has no effect on noncollagen protein production; a 5 mM L-fucose concentration causes a maximum decrease in both collagen and noncollagen protein production. This defect is unrelated to the reduction in myo-inositol uptake caused by L-fucose and is not prevented by aminoguanidine. Collagen production can be improved by restoring L-fucose-conditioned cells to normal medium. Culturing cells for 2 weeks in medium containing 10 mM L-fucose resulted in a 50% decrease in collagen production, which was restored to 75% of control after cells were transferred to normal medium for 7 days. In contrast, noncollagen protein production was totally restored after 3 days in normal medium. Increasing levels of L-fucose in serum of rats also resulted in a decrease in collagen production. Collagenase digestible incorporation of L-[2,3,4,5-3H]proline into protein of the articular cartilage from rats fed a diet containing 20% L-fucose for 3 weeks was reduced by about 40% compared to rats fed a normal diet. The decrease in collagen production in L-fucose fed rats was less than the reduction that occurred in streptozotocin-induced diabetic rats. These data suggest that changes in L-fucose concentration itself may be a factor in the regulation of collagen production.

L-fucose is a potent inhibitor of myo-inositol transport and metabolism in cultured neuroblastoma cells.

It has been proposed that abnormal myo-inositol metabolism may be a factor in the development of diabetic complications. Studies with animal models of diabetes and cultured cells have suggested that hyperglycemia by an unknown mechanism may alter myo-inositol metabolism and content. Recently, we have shown that L-fucose, a 6-deoxy sugar whose content has been reported to be increased in diabetes, is a potent inhibitor of myo-inositol transport. To examine the effect of L-fucose on myo-inositol metabolism, neuroblastoma cells were cultured in medium supplemented with L-fucose. L-Fucose is a competitive inhibitor of Na(+)-dependent, high-affinity myo-inositol transport. The Ki for inhibition of myo-inositol transport by L-fucose is about 3 mM. L-Fucose is taken up and accumulates in neuroblastoma cells. The uptake of L-fucose is inhibited by Na+ depletion, D-glucose, glucose analogues, phloridzin, and cytochalasin B. In contrast, neither myo-inositol nor L-glucose inhibits L-fucose uptake. Chronic exposure of neuroblastoma cells to 1-30 mM L-fucose causes a decrease in myo-inositol accumulation and incorporation into inositol phospholipids, intracellular free myo-inositol content, and phosphatidylinositol levels. Na+,K(+)-ATPase transport activity is decreased by about 15% by acute or chronic exposure of neuroblastoma cells to L-fucose. Similar defects occur when neuroblastoma cells are exposed chronically to 30 mM glucose. Cell myo-inositol metabolism and Na+/K(+)-pump activity are maintained when 250 microM myo-inositol is added to the L-fucose-supplemented medium. Unlike the effect of chronic exposure of neuroblastoma cells to medium containing 30 mM glucose, the resting membrane potential of neuroblastoma cells is not altered by chronic exposure of the cells to 30 mM L-fucose. The effect of L-fucose on cultured neuroblastoma cell properties occurs at concentrations of L-fucose which may exist in the diabetic milieu. These data suggest that increased concentrations of L-fucose may have a role in myo-inositol-related defects in mammalian cells.

Rapid, simple enzymatic assay of free L-fucose in serum and urine, and its use as a marker for cancer, cirrhosis, and gastric ulcers

We devised a kit for use with automated analyzers, for assay of urinary free L-fucose by means of a newly isolated L-fucose dehydrogenase (EC 1.1.1.122), and we measured L-fucose in healthy subjects, cancer patients, and patients with other diseases. It takes 10 min to complete one assay. Absorbance and L-fucose concentration were linearly related up to at least 3.0 mmol/L, analytical recovery was 90-104%, and intra- and interassay coefficients of variation were less than 4.2% and 7.8%, respectively. The concentrations of L-fucose, corrected for creatinine, were significantly higher than those in healthy subjects in nine of 18 patients with gastric ulcers, 19 of 21 patients with cirrhosis of the liver, and 206 of 366 patients with some type of cancer, reflecting a changed L-fucose metabolism. Because urine specimens are analyzed and the test is rapid and inexpensive, this method may be suitable for mass screening for some kinds of cancer, cirrhosis, and gastric ulcers.

L-Fucose blocks MIF/MAF priming of rabbit alveolar macrophages for a PMA-induced oxidative response

The effect of l-fucose on the priming of AM from normal adult rabbits and their subsequent chemiluminescent (CL) responses to phorbol myristate acetate (PMA) was investigated. It was observed that 12.5 m M l-fucose, but not d-fucose, blocked the “spontaneous” priming of normal AM during an 18-hr incubation period in serum-free RPMI 1640 medium by about 40% ( P < 0.01) as detected by their CL responses to a PMA challenge. In addition, the optimal concentration of l-fucose (12.5 m M) blocked MIF/MAF priming during the 3- or 18-hr incubaion period by 71 or 93% ( P < 0.05), respectively, as determined by their CL responses following PMA challenge. It is of particular significance that d-fucose was inactive. These results, together with previously published data, indicate that l-fucose (a) blocks priming of AM for an oxidative response, (b) stimulates random migration of AM, and (c) reverses migration inhibition produced by migration inhibition factor.

Glycoproteins of axonal transport: Polypeptides interacting with the lectin from Aleuria aurantia

The interaction between a new fucose-specific lectin from Aleuria aurantia and brain glycoproteins is described. It was found that several different glycoproteins could bind to a column of immobilized Aleuria lectin and that the bound material could be eluted with low concentrations of l-fucose. The polypeptide pattern of the bound glycoproteins differed markedly from that of unbound glycoproteins. A major portion of rapidly transported fucose-labelled glycoproteins from retinal ganglion cells bound to the Aleuria lectin. This chromatographic procedure led to a considerable purification of the rapidly transported glycoproteins. The major labelled, rapidly transported polypeptide which bound to the Aleuria lectin had an apparent mol. wt. of 114,000.

Evaluation of the level of mucopolysaccharides in serum in bilharziasis

Total protein-bound polysaccharides (calculated as uronic acid and hexosamine), hexose, l-fucose and N-acetylneuraminic acid in serum have been estimated in 25 normal subjects and 43 bilharziasis patients. The bilharziasis patients were divided into four groups according to the severity and progress of the disease, those with active bilharziasis infection, those with clinical hepatosplenomegaly, those with both clinical hepatosplenomegaly and active bilharziasis infection and those with clinical hepatosplenomegaly plus ascites. The concentrations of serum total protein-bound uronic acid, hexosamine, hexose and lL-fucose were significantly elevated in all the groups of patients studied, while the concentrations of N-acetylneuraminic acid were slightly elevated. The concentration of l-fucose was greatly elevated in all the groups of patients studied. There is evidence that the concentrations of uronic acid and hexosamine increased with the severity and progress of the disease.

The fucose and agglutinogen contents of saliva in subjects with duodenal ulcers.

Abstract The concentration of l-fucose in saliva has been determined in 472 subjects, 332 of whom were free of p≐ptic ulcer symptoms and 140 of whom had duodenal ulcers. The ABO blood group and ABH secretor status of these subjects was determined. It has been shown that there is a significant correlation between log 10 salivary fucose concentration and salivary agglutination-inhibition titer for the following agglutinogens: H in blood group A, B, and O secretors, B in blood group B secretors, and Le a in blood group O nonsecretors. The correlation between log 10 salivary fucose concentration and salivary agglutinogen titer of H in blood group O secretors held true when both Ulex extract and eel serum were used as antisera. Significant correlation was absent between log 10 salivary fucose concentration and salivary A agglutinogen titer in blood group A secretors. The estimation of fucose in saliva is accurate to approximately 1 per cent. In view of the correlations found between salivary agglutinogen titer and salivary fucose concentration, it would appear that the latter is an accurate index of the total salivary blood group substance concentration. Nonsecretors of ABH substances have been found to have almost as high a salivary fucose concentration as do ABH secretors. It has been computed that the mean total blood group substance concentration is of the same order, regardless of blood group or ABH secretor status. ABH secretor and ABH nonsecretor blood group O subjects with duodenal ulcers have the same salivary fucose concentrations as the corresponding phenotypic classes without ulcers. These findings suggest that the increased susceptibility of ABH nonsecretors to develop duodenal ulcers, when compared with ABH secretors, is not caused by the ABH nonsecretors having lower total blood group substance concentrations in their body liquids. The results further suggest that subjects who have developed duodenal ulcers have not done so because their body liquids (as exemplified by saliva) have lower total blood group substance concentrations than do those of subjects without ulcers.