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Bo Wang - One of the best experts on this subject based on the ideXlab platform.
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dietary Sialic Acid supplementation improves learning and memory in piglets
The American Journal of Clinical Nutrition, 2007Co-Authors: Bo Wang, Peter Petocz, Bing Yu, Muhsin Karim, Honghua Hu, Paul D Mcgreevy, Suzanne D E Held, Janette C BrandmillerAbstract:Background: Sialic Acid, a key component of both human milk oligosaccharides and neural tissues, may be a conditional nutrient during periods of rapid brain growth. Objective:WetestedthehypothesisthatvariationsintheSialicAcid content of a formula milk would influence early learning behavior and gene expression of enzymes involved in Sialic Acid metabolism in piglets. Design:Piglets(n54)wereallocatedto1of4groupsfedsowmilk replacer supplemented with increasing amounts of Sialic Acid as caseinglycomacropeptidefor35d.Learningperformanceandmemory were assessed with the use of easy and difficult visual cues in an 8-arm radial maze. Brain ganglioside and sialoprotein concentrations and mRNA expression of 2 learning-associated genes (ST8SIA4 and GNE) were measured. Results: In both tests, the supplemented groups learned in significantly fewer trials than did the control group, with a dose-response relationforthedifficulttask(P0.018)butnottheeasytask.Inthe hippocampus,significantdose-responserelationswereobservedbetween amount of Sialic Acid supplementation and mRNA levels of ST8SIA4 (P 0.002) and GNE (P 0.004), corresponding with proportionate increases in protein-bound Sialic Acid concentrations in the frontal cortex. Conclusions: Feeding a protein-bound source of Sialic Acid during early development enhanced learning and increased expression of 2 genes associated with learning in developing piglets. Sialic Acid in mammalian milks could play a role in cognitive development. Am J Clin Nutr 2007;85:561–9.
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The role and potential of Sialic Acid in human nutrition
European Journal of Clinical Nutrition, 2003Co-Authors: Bo Wang, Jennie Brand-millerAbstract:Sialic Acids are a family of nine-carbon Acidic monosaccharides that occur naturally at the end of sugar chains attached to the surfaces of cells and soluble proteins. In the human body, the highest concentration of Sialic Acid (as N -acetylneuraminic Acid) occurs in the brain where it participates as an integral part of ganglioside structure in synaptogenesis and neural transmission. Human milk also contains a high concentration of Sialic Acid attached to the terminal end of free oligosaccharides, but its metabolic fate and biological role are currently unknown. An important question is whether the Sialic Acid in human milk is a conditional nutrient and confers developmental advantages on breast-fed infants compared to those fed infant formula. In this review, we critically discuss the current state of knowledge of the biology and role of Sialic Acid in human milk and nervous tissue, and the link between Sialic Acid, breastfeeding and learning behaviour.
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concentration and distribution of Sialic Acid in human milk and infant formulas
The American Journal of Clinical Nutrition, 2001Co-Authors: Bo Wang, Patricia Mcveagh, Janette C Brandmiller, Peter PetoczAbstract:Background: In animal studies, Sialic Acid supplementation is associated with increases of gangliosides in the brain and improved learning ability. Only limited data are available on the Sialic Acid content of human milk and infant formulas. Objective: We compared the concentrations of oligosaccharide-bound, protein-bound, and free Sialic Acid in milk from mothers of full-term and preterm infants and in a range of infant formulas. Design: The milk from 20 and 14 mothers of full-term and preterm infants (mean gestational age: 31 ± 3 wk), respectively. was collected at 4 stages of lactation (colostrum, transition, 1 mo, and 3 mo) and compared with 21 different infant formulas. Results: Total Sialic Acid concentrations were highest in colostrum (x ± SEM: 5.04 ± 0.21 mmol/L in full term) and decreased by nearly 80% over the next 3 mo. Human milk from mothers of preterm infants contained 13-23% more Sialic Acid than did milk from mothers of full-term infants at 3 of the 4 lactation stages (P < 0.02). The Sialic Acid content of most formulas was <25% of that found in mature human milk (P < 0.01). Most of the Sialic Acid in the formulas ( 70%) was bound to glycoproteins, whereas in human milk most Sialic Acid was bound to free oligosaccharides. Conclusions: Human milk, including milk from mothers of preterm infants, is a rich source of oligosaccharide-bound Sialic Acid, which contrasts with the relatively small amounts found in infant formulas. The nutritional significance of Sialic Acid is presently unknown, but it is plausible that it is a conditional nutrient that contributes to Sialic Acid accretion in the brain.
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concentration and distribution of Sialic Acid in human milk and infant formulas
The American Journal of Clinical Nutrition, 2001Co-Authors: Bo Wang, Patricia Mcveagh, Janette C Brandmiller, Peter PetoczAbstract:BACKGROUND: In animal studies, Sialic Acid supplementation is associated with increases of gangliosides in the brain and improved learning ability. Only limited data are available on the Sialic Acid content of human milk and infant formulas. OBJECTIVE: We compared the concentrations of oligosaccharide-bound, protein-bound, and free Sialic Acid in milk from mothers of full-term and preterm infants and in a range of infant formulas. DESIGN: The milk from 20 and 14 mothers of full-term and preterm infants (mean gestational age: 31 +/- 3 wk), respectively, was collected at 4 stages of lactation (colostrum, transition, 1 mo, and 3 mo) and compared with 21 different infant formulas. RESULTS: Total Sialic Acid concentrations were highest in colostrum (x +/- SEM: 5.04 +/- 0.21 mmol/L in full term) and decreased by nearly 80% over the next 3 mo. Human milk from mothers of preterm infants contained 13-23% more Sialic Acid than did milk from mothers of full-term infants at 3 of the 4 lactation stages (P < 0.02). The Sialic Acid content of most formulas was <25% of that found in mature human milk (P < 0.01). Most of the Sialic Acid in the formulas ( approximately 70%) was bound to glycoproteins, whereas in human milk most Sialic Acid was bound to free oligosaccharides. CONCLUSIONS: Human milk, including milk from mothers of preterm infants, is a rich source of oligosaccharide-bound Sialic Acid, which contrasts with the relatively small amounts found in infant formulas. The nutritional significance of Sialic Acid is presently unknown, but it is plausible that it is a conditional nutrient that contributes to Sialic Acid accretion in the brain.
Graham P Stafford - One of the best experts on this subject based on the ideXlab platform.
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Sialic Acid transporter nant participates in tannerella forsythia biofilm formation and survival on epithelial cells
Microbial Pathogenesis, 2016Co-Authors: Kiyonobu Honma, Graham P Stafford, Angela Ruscitto, Andrew M Frey, Ashu SharmaAbstract:Tannerella forsythia is a periodontal pathogen implicated in periodontitis. This gram-negative pathogen depends on exogenous peptidoglycan amino sugar N-acetylmuramic Acid (NAM) for growth. In the biofilm state the bacterium can utilize Sialic Acid (Neu5Ac) instead of NAM to sustain its growth. Thus, the Sialic Acid utilization system of the bacterium plays a critical role in the growth and survival of the organism in the absence of NAM. We sought the function of a T. forsythia gene annotated as nanT coding for an inner-membrane sugar transporter located on a Sialic Acid utilization genetic cluster. To determine the function of this putative Sialic Acid transporter, an isogenic nanT-deletion mutant generated by allelic replacement strategy was evaluated for biofilm formation on NAM or Neu5Ac, and survival on KB epithelial cells. Moreover, since T. forsythia forms synergistic biofilms with Fusobacterium nucleatum, co-biofilm formation activity in mixed culture and Sialic Acid uptake in culture were also assessed. The data showed that the nanT-inactivated mutant of T. forsythia was attenuated in its ability to uptake Sialic Acid. The mutant formed weaker biofilms compared to the wild-type strain in the presence of Sialic Acid and as co-biofilms with F. nucleatum. Moreover, compared to the wild-type T. forsythia nanT-inactivated mutant showed reduced survival when incubated on KB epithelial cells. Taken together, the data presented here demonstrate that NanT-mediated Sialic transportation is essential for Sialic Acid utilization during biofilm growth and survival of the organism on epithelial cells and implies Sialic Acid might be key for its survival both in subgingival biofilms and during infection of human epithelial cells in vivo.
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a novel Sialic Acid utilization and uptake system in the periodontal pathogen tannerella forsythia
Journal of Bacteriology, 2010Co-Authors: C Ian W Douglas, Graham P StaffordAbstract:Tannerella forsythia is a key contributor to periodontitis, but little is known of its virulence mechanisms. In this study we have investigated the role of Sialic Acid in biofilm growth of this periodontal pathogen. Our data show that biofilm growth of T. forsythia is stimulated by Sialic Acid, glycolyl Sialic Acid, and sialyllactose, all three of which are common sugar moieties on a range of important host glycoproteins. We have also established that growth on sialyllactose is dependent on the sialidase of T. forsythia since the sialidase inhibitor oseltamivir suppresses growth on sialyllactose. The genome of T. forsythia contains a Sialic Acid utilization locus, which also encodes a putative inner membrane Sialic Acid permease (NanT), and we have shown this is functional when it is expressed in Escherichia coli. This genomic locus also contains a putatively novel TonB-dependent outer membrane Sialic Acid transport system (TF0033-TF0034). In complementation studies using an Escherichia coli strain devoid of its outer membrane Sialic Acid transporters, the cloning and expression of the TF0033-TF0034 genes enabled an E. coli nanR nanC ompR strain to utilize Sialic Acid as the sole carbon and energy source. We have thus identified a novel Sialic Acid uptake system that couples an inner membrane permease with a TonB-dependent outer membrane transporter, and we propose to rename these novel Sialic Acid uptake genes nanO and nanU, respectively. Taken together, these data indicate that Sialic Acid is a key growth factor for this little-characterized oral pathogen and may be key to its physiology in vivo.
Peter Petocz - One of the best experts on this subject based on the ideXlab platform.
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dietary Sialic Acid supplementation improves learning and memory in piglets
The American Journal of Clinical Nutrition, 2007Co-Authors: Bo Wang, Peter Petocz, Bing Yu, Muhsin Karim, Honghua Hu, Paul D Mcgreevy, Suzanne D E Held, Janette C BrandmillerAbstract:Background: Sialic Acid, a key component of both human milk oligosaccharides and neural tissues, may be a conditional nutrient during periods of rapid brain growth. Objective:WetestedthehypothesisthatvariationsintheSialicAcid content of a formula milk would influence early learning behavior and gene expression of enzymes involved in Sialic Acid metabolism in piglets. Design:Piglets(n54)wereallocatedto1of4groupsfedsowmilk replacer supplemented with increasing amounts of Sialic Acid as caseinglycomacropeptidefor35d.Learningperformanceandmemory were assessed with the use of easy and difficult visual cues in an 8-arm radial maze. Brain ganglioside and sialoprotein concentrations and mRNA expression of 2 learning-associated genes (ST8SIA4 and GNE) were measured. Results: In both tests, the supplemented groups learned in significantly fewer trials than did the control group, with a dose-response relationforthedifficulttask(P0.018)butnottheeasytask.Inthe hippocampus,significantdose-responserelationswereobservedbetween amount of Sialic Acid supplementation and mRNA levels of ST8SIA4 (P 0.002) and GNE (P 0.004), corresponding with proportionate increases in protein-bound Sialic Acid concentrations in the frontal cortex. Conclusions: Feeding a protein-bound source of Sialic Acid during early development enhanced learning and increased expression of 2 genes associated with learning in developing piglets. Sialic Acid in mammalian milks could play a role in cognitive development. Am J Clin Nutr 2007;85:561–9.
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concentration and distribution of Sialic Acid in human milk and infant formulas
The American Journal of Clinical Nutrition, 2001Co-Authors: Bo Wang, Patricia Mcveagh, Janette C Brandmiller, Peter PetoczAbstract:Background: In animal studies, Sialic Acid supplementation is associated with increases of gangliosides in the brain and improved learning ability. Only limited data are available on the Sialic Acid content of human milk and infant formulas. Objective: We compared the concentrations of oligosaccharide-bound, protein-bound, and free Sialic Acid in milk from mothers of full-term and preterm infants and in a range of infant formulas. Design: The milk from 20 and 14 mothers of full-term and preterm infants (mean gestational age: 31 ± 3 wk), respectively. was collected at 4 stages of lactation (colostrum, transition, 1 mo, and 3 mo) and compared with 21 different infant formulas. Results: Total Sialic Acid concentrations were highest in colostrum (x ± SEM: 5.04 ± 0.21 mmol/L in full term) and decreased by nearly 80% over the next 3 mo. Human milk from mothers of preterm infants contained 13-23% more Sialic Acid than did milk from mothers of full-term infants at 3 of the 4 lactation stages (P < 0.02). The Sialic Acid content of most formulas was <25% of that found in mature human milk (P < 0.01). Most of the Sialic Acid in the formulas ( 70%) was bound to glycoproteins, whereas in human milk most Sialic Acid was bound to free oligosaccharides. Conclusions: Human milk, including milk from mothers of preterm infants, is a rich source of oligosaccharide-bound Sialic Acid, which contrasts with the relatively small amounts found in infant formulas. The nutritional significance of Sialic Acid is presently unknown, but it is plausible that it is a conditional nutrient that contributes to Sialic Acid accretion in the brain.
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concentration and distribution of Sialic Acid in human milk and infant formulas
The American Journal of Clinical Nutrition, 2001Co-Authors: Bo Wang, Patricia Mcveagh, Janette C Brandmiller, Peter PetoczAbstract:BACKGROUND: In animal studies, Sialic Acid supplementation is associated with increases of gangliosides in the brain and improved learning ability. Only limited data are available on the Sialic Acid content of human milk and infant formulas. OBJECTIVE: We compared the concentrations of oligosaccharide-bound, protein-bound, and free Sialic Acid in milk from mothers of full-term and preterm infants and in a range of infant formulas. DESIGN: The milk from 20 and 14 mothers of full-term and preterm infants (mean gestational age: 31 +/- 3 wk), respectively, was collected at 4 stages of lactation (colostrum, transition, 1 mo, and 3 mo) and compared with 21 different infant formulas. RESULTS: Total Sialic Acid concentrations were highest in colostrum (x +/- SEM: 5.04 +/- 0.21 mmol/L in full term) and decreased by nearly 80% over the next 3 mo. Human milk from mothers of preterm infants contained 13-23% more Sialic Acid than did milk from mothers of full-term infants at 3 of the 4 lactation stages (P < 0.02). The Sialic Acid content of most formulas was <25% of that found in mature human milk (P < 0.01). Most of the Sialic Acid in the formulas ( approximately 70%) was bound to glycoproteins, whereas in human milk most Sialic Acid was bound to free oligosaccharides. CONCLUSIONS: Human milk, including milk from mothers of preterm infants, is a rich source of oligosaccharide-bound Sialic Acid, which contrasts with the relatively small amounts found in infant formulas. The nutritional significance of Sialic Acid is presently unknown, but it is plausible that it is a conditional nutrient that contributes to Sialic Acid accretion in the brain.
Janette C Brandmiller - One of the best experts on this subject based on the ideXlab platform.
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dietary Sialic Acid supplementation improves learning and memory in piglets
The American Journal of Clinical Nutrition, 2007Co-Authors: Bo Wang, Peter Petocz, Bing Yu, Muhsin Karim, Honghua Hu, Paul D Mcgreevy, Suzanne D E Held, Janette C BrandmillerAbstract:Background: Sialic Acid, a key component of both human milk oligosaccharides and neural tissues, may be a conditional nutrient during periods of rapid brain growth. Objective:WetestedthehypothesisthatvariationsintheSialicAcid content of a formula milk would influence early learning behavior and gene expression of enzymes involved in Sialic Acid metabolism in piglets. Design:Piglets(n54)wereallocatedto1of4groupsfedsowmilk replacer supplemented with increasing amounts of Sialic Acid as caseinglycomacropeptidefor35d.Learningperformanceandmemory were assessed with the use of easy and difficult visual cues in an 8-arm radial maze. Brain ganglioside and sialoprotein concentrations and mRNA expression of 2 learning-associated genes (ST8SIA4 and GNE) were measured. Results: In both tests, the supplemented groups learned in significantly fewer trials than did the control group, with a dose-response relationforthedifficulttask(P0.018)butnottheeasytask.Inthe hippocampus,significantdose-responserelationswereobservedbetween amount of Sialic Acid supplementation and mRNA levels of ST8SIA4 (P 0.002) and GNE (P 0.004), corresponding with proportionate increases in protein-bound Sialic Acid concentrations in the frontal cortex. Conclusions: Feeding a protein-bound source of Sialic Acid during early development enhanced learning and increased expression of 2 genes associated with learning in developing piglets. Sialic Acid in mammalian milks could play a role in cognitive development. Am J Clin Nutr 2007;85:561–9.
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concentration and distribution of Sialic Acid in human milk and infant formulas
The American Journal of Clinical Nutrition, 2001Co-Authors: Bo Wang, Patricia Mcveagh, Janette C Brandmiller, Peter PetoczAbstract:Background: In animal studies, Sialic Acid supplementation is associated with increases of gangliosides in the brain and improved learning ability. Only limited data are available on the Sialic Acid content of human milk and infant formulas. Objective: We compared the concentrations of oligosaccharide-bound, protein-bound, and free Sialic Acid in milk from mothers of full-term and preterm infants and in a range of infant formulas. Design: The milk from 20 and 14 mothers of full-term and preterm infants (mean gestational age: 31 ± 3 wk), respectively. was collected at 4 stages of lactation (colostrum, transition, 1 mo, and 3 mo) and compared with 21 different infant formulas. Results: Total Sialic Acid concentrations were highest in colostrum (x ± SEM: 5.04 ± 0.21 mmol/L in full term) and decreased by nearly 80% over the next 3 mo. Human milk from mothers of preterm infants contained 13-23% more Sialic Acid than did milk from mothers of full-term infants at 3 of the 4 lactation stages (P < 0.02). The Sialic Acid content of most formulas was <25% of that found in mature human milk (P < 0.01). Most of the Sialic Acid in the formulas ( 70%) was bound to glycoproteins, whereas in human milk most Sialic Acid was bound to free oligosaccharides. Conclusions: Human milk, including milk from mothers of preterm infants, is a rich source of oligosaccharide-bound Sialic Acid, which contrasts with the relatively small amounts found in infant formulas. The nutritional significance of Sialic Acid is presently unknown, but it is plausible that it is a conditional nutrient that contributes to Sialic Acid accretion in the brain.
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concentration and distribution of Sialic Acid in human milk and infant formulas
The American Journal of Clinical Nutrition, 2001Co-Authors: Bo Wang, Patricia Mcveagh, Janette C Brandmiller, Peter PetoczAbstract:BACKGROUND: In animal studies, Sialic Acid supplementation is associated with increases of gangliosides in the brain and improved learning ability. Only limited data are available on the Sialic Acid content of human milk and infant formulas. OBJECTIVE: We compared the concentrations of oligosaccharide-bound, protein-bound, and free Sialic Acid in milk from mothers of full-term and preterm infants and in a range of infant formulas. DESIGN: The milk from 20 and 14 mothers of full-term and preterm infants (mean gestational age: 31 +/- 3 wk), respectively, was collected at 4 stages of lactation (colostrum, transition, 1 mo, and 3 mo) and compared with 21 different infant formulas. RESULTS: Total Sialic Acid concentrations were highest in colostrum (x +/- SEM: 5.04 +/- 0.21 mmol/L in full term) and decreased by nearly 80% over the next 3 mo. Human milk from mothers of preterm infants contained 13-23% more Sialic Acid than did milk from mothers of full-term infants at 3 of the 4 lactation stages (P < 0.02). The Sialic Acid content of most formulas was <25% of that found in mature human milk (P < 0.01). Most of the Sialic Acid in the formulas ( approximately 70%) was bound to glycoproteins, whereas in human milk most Sialic Acid was bound to free oligosaccharides. CONCLUSIONS: Human milk, including milk from mothers of preterm infants, is a rich source of oligosaccharide-bound Sialic Acid, which contrasts with the relatively small amounts found in infant formulas. The nutritional significance of Sialic Acid is presently unknown, but it is plausible that it is a conditional nutrient that contributes to Sialic Acid accretion in the brain.
Xi Chen - One of the best experts on this subject based on the ideXlab platform.
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Sialic Acid metabolism and sialyltransferases: natural functions and applications
Applied Microbiology and Biotechnology, 2012Co-Authors: Yanhong Li, Xi ChenAbstract:Sialic Acids are a family of negatively charged monosaccharides which are commonly presented as the terminal residues in glycans of the glycoconjugates on eukaryotic cell surface or as components of capsular polysaccharides or lipooligosaccharides of some pathogenic bacteria. Due to their important biological and pathological functions, the biosynthesis, activation, transfer, breaking down, and recycle of Sialic Acids are attracting increasing attention. The understanding of the Sialic Acid metabolism in eukaryotes and bacteria leads to the development of metabolic engineering approaches for elucidating the important functions of Sialic Acid in mammalian systems and for large-scale production of sialosides using engineered bacterial cells. As the key enzymes in biosynthesis of sialylated structures, sialyltransferases have been continuously identified from various sources and characterized. Protein crystal structures of seven sialyltransferases have been reported. Wild-type sialyltransferases and their mutants have been applied with or without other sialoside biosynthetic enzymes for producing complex Sialic Acid-containing oligosaccharides and glycoconjugates. This mini-review focuses on current understanding and applications of Sialic Acid metabolism and sialyltransferases.
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pasteurella multocida cmp Sialic Acid synthetase and mutants of neisseria meningitidis cmp Sialic Acid synthetase with improved substrate promiscuity
Applied Microbiology and Biotechnology, 2012Co-Authors: Yanhong Li, Hai Yu, Saddam Muthana, Xi ChenAbstract:Cytidine 5′-monophosphate (CMP)-Sialic Acid synthetases (CSSs) catalyze the formation of CMP-Sialic Acid from CTP and Sialic Acid, a key step for sialyltransferase-catalyzed biosynthesis of Sialic Acid-containing oligosaccharides and glycoconjugates. More than 50 different Sialic Acid forms have been identified in nature. To facilitate the enzymatic synthesis of sialosides with diverse naturally occurring Sialic Acid forms and their non-natural derivatives, CMP-Sialic Acid synthetases with promiscuous substrate specificity are needed. Herein we report the cloning, characterization, and substrate specificity studies of a new CSS from Pasteurella multocida strain P-1059 (PmCSS) and a CSS from Haemophillus ducreyi (HdCSS). Based on protein sequence alignment and substrate specificity studies of these two CSSs and a Neisseria meningitidis CSS (NmCSS), as well as crystal structure modeling and analysis of NmCSS, NmCSS mutants (NmCSS_S81R and NmCSS_Q163A) with improved substrate promiscuity were generated. The strategy of combining substrate specificity studies of enzymes from different sources and protein crystal structure studies can be a general approach for designing enzyme mutants with improved activity and substrate promiscuity.
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General consideration on Sialic Acid chemistry.
Methods of Molecular Biology, 2011Co-Authors: Xi ChenAbstract:: Sialic Acids, also known as neuraminic Acids, are a family of negatively charged α-keto Acids with a nine-carbon backbone. These unique sugars have been found at the termini of many glycan chains of vertebrate cell surface, which play pivotal roles in mediating or modulating a variety of physiological and pathological processes. This brief review covers general approaches for synthesizing Sialic Acid containing structures. Recently developed synthetic methods along with structural diversities and biological functions of Sialic Acid are discussed.
