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Margaret E Daub - One of the best experts on this subject based on the ideXlab platform.
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the sos4 pyridoxal kinase is required for maintenance of vitamin b6 mediated processes in chloroplasts
Plant Physiology and Biochemistry, 2013Co-Authors: Elizabeth E Rueschhoff, Jeffrey W Gillikin, Heike Sederoff, Margaret E DaubAbstract:Abstract Vitamin B 6 (pyridoxal 5′-phosphate and its Vitamers) is an important cofactor in numerous enzymatic reactions. In spite of its importance, the consequences of altering vitamin B 6 content on plant growth and development are not well understood. This study compares two mutants for vitamin B 6 -metabolizing enzymes in Arabidopsis thaliana : a pdx1.3 mutant in the de novo synthesis pathway and a salvage pathway sos4 mutant that accumulates more vitamin B 6 . We show that despite a difference in total B 6 content in leaf tissue, both mutants share similar phenotypes, including chlorosis, decreased size, altered chloroplast ultrastructure, and root sensitivity to sucrose. Assay of B 6 Vitamer content from isolated chloroplasts showed that, despite differing B 6 Vitamer content in whole leaf tissue, both mutants share a common deficiency in total and phosphorylated Vitamers in chloroplasts. One of the splice variants of the SOS4 proteins was shown to be located in the chloroplast. Our data indicate that some of the phenotypic consequences shared between the pdx1.3 and sos4 mutants are due to B 6 deficiency in chloroplasts, and show that SOS4 is required for maintenance of phosphorylated B 6 Vitamer concentrations in chloroplasts. Further, our data are consistent with a diffusion model for transport of vitamin B 6 into chloroplasts.
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Vitamer levels stress response enzyme activity and gene regulation of arabidopsis lines mutant in the pyridoxine pyridoxamine 5 phosphate oxidase pdx3 and the pyridoxal kinase sos4 genes involved in the vitamin b6 salvage pathway
Plant Physiology, 2007Co-Authors: Eugenia Gonzalez, David A Danehower, Margaret E DaubAbstract:PDX3 and SALT OVERLY SENSITIVE4 (SOS4), encoding pyridoxine/pyridoxamine 5′-phosphate oxidase and pyridoxal kinase, respectively, are the only known genes involved in the salvage pathway of pyridoxal 5′-phosphate in plants. In this study, we determined the phenotype, stress responses, Vitamer levels, and regulation of the vitamin B6 pathway genes in Arabidopsis (Arabidopsis thaliana) plants mutant in PDX3 and SOS4. sos4 mutant plants showed a distinct phenotype characterized by chlorosis and reduced plant size, as well as hypersensitivity to sucrose in addition to the previously noted NaCl sensitivity. This mutant had higher levels of pyridoxine, pyridoxamine, and pyridoxal 5′-phosphate than the wild type, reflected in an increase in total vitamin B6 observed through HPLC analysis and yeast bioassay. The sos4 mutant showed increased activity of PDX3 as well as of the B6 de novo pathway enzyme PDX1, correlating with increased total B6 levels. Two independent lines with T-DNA insertions in the promoter region of PDX3 (pdx3-1 and pdx3-2) had decreased PDX3 activity. Both also had decreased activity of PDX1, which correlated with lower levels of total vitamin B6 observed using the yeast bioassay; however, no differences were noted in levels of individual Vitamers by HPLC analysis. Both pdx3 mutants showed growth reduction in vitro and in vivo as well as an inability to increase growth under high light conditions. Increased expression of salvage and some of the de novo pathway genes was observed in both the pdx3 and sos4 mutants. In all mutants, increased expression was more dramatic for the salvage pathway genes.
Mario Irano - One of the best experts on this subject based on the ideXlab platform.
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normal phase high performance liquid chromatography method for the determination of tocopherols and tocotrienols in cereals
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Gianfranco Panfili, Alessandra Fratianni, Mario IranoAbstract:The eight Vitamers of vitamin E (α-, β-, γ-, and δ-tocopherols and -tocotrienols) have different antioxidant and biological activities and have different distributions in foods. Some cereals, especially oat, rye, and barley, are good sources of tocotrienols. A fast procedure for the determination of tocopherols and tocotrienols (tocols) in cereal foods was developed. It involves sample saponification and extraction followed by normal phase high-performance liquid chromatography (HPLC). The results have been compared with those found by direct extraction without saponification. The method is sensitive and selective enough to be tested on a wide variety of cereal samples. The highest tocol levels were found in soft wheat and barley (∼75 mg/kg of dry weight). β-Tocotrienol is the main Vitamer found in hulled and dehulled wheats (from 33 to 43 mg/kg of dry weight), γ-tocopherol predominates in maize (45 mg/kg of dry weight) ), and α-tocotrienol predominates in oat and barley (56 and 40 mg/kg of dry weight, re...
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normal phase high performance liquid chromatography method for the determination of tocopherols and tocotrienols in cereals
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Gianfranco Panfili, Alessandra Fratianni, Mario IranoAbstract:The eight Vitamers of vitamin E (alpha-, beta-, gamma-, and delta-tocopherols and -tocotrienols) have different antioxidant and biological activities and have different distributions in foods. Some cereals, especially oat, rye, and barley, are good sources of tocotrienols. A fast procedure for the determination of tocopherols and tocotrienols (tocols) in cereal foods was developed. It involves sample saponification and extraction followed by normal phase high-performance liquid chromatography (HPLC). The results have been compared with those found by direct extraction without saponification. The method is sensitive and selective enough to be tested on a wide variety of cereal samples. The highest tocol levels were found in soft wheat and barley ( approximately 75 mg/kg of dry weight). beta-Tocotrienol is the main Vitamer found in hulled and dehulled wheats (from 33 to 43 mg/kg of dry weight), gamma-tocopherol predominates in maize (45 mg/kg of dry weight) ), and alpha-tocotrienol predominates in oat and barley (56 and 40 mg/kg of dry weight, respectively).
Monique Albersen - One of the best experts on this subject based on the ideXlab platform.
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Vitamin B-6 Vitamers in human plasma and cerebrospinal fluid1–4
2016Co-Authors: Monique Albersen, Marjolein Bosma, Jurjen J. Luykx, Judith J.m. Jans, Steven C. Bakker, Eric Strengman, P Borgdorff, Nine Vvam Knoers, Roel A Ophoff, A M Verhoeven-duifAbstract:Background: Vitamin B-6 comprises a group of 6 interrelated vi-tamers and is essential for numerous physiologic processes, includ-ing brain functioning. Genetic disorders disrupting vitamin B-6 metabolism have severe clinical consequences. Objective: To adequately diagnose known and novel disorders in vitamin B-6 metabolism, a reference set is required containing in-formation on all vitamin B-6 Vitamers in plasma and cerebrospinal fluid (CSF). Design: Concentrations of B-6 Vitamers in the plasma and CSF of 533 adult subjects were measured by ultra high-performance liquid chromatography–tandem mass spectrometry. Results: The relative B-6 Vitamer composition of plasma [pyridoxal phosphate (PLP). pyridoxic acid (PA). pyridoxal] differed fro
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vitamin b6 in plasma and cerebrospinal fluid of children
PLOS ONE, 2015Co-Authors: Monique Albersen, Marjolein Bosma, Judith J.m. Jans, Gepke Visser, Floris C Hofstede, Peter M Van Hasselt, Monique G M De Sainvan Der Velden, Nanda M VerhoevenduifAbstract:Background Over the past years, the essential role of vitamin B6 in brain development and functioning has been recognized and genetic metabolic disorders resulting in functional vitamin B6 deficiency have been identified. However, data on B6 Vitamers in children are scarce. Materials and Methods B6 Vitamer concentrations in simultaneously sampled plasma and cerebrospinal fluid (CSF) of 70 children with intellectual disability were determined by ultra performance liquid chro-matography-tandem mass spectrometry. For ethical reasons, CSF samples could not be obtained from healthy children. The influence of sex, age, epilepsy and treatment with antiepileptic drugs, were investigated. Results The B6 Vitamer composition of plasma (pyridoxal phosphate (PLP) > pyridoxic acid > pyridoxal (PL)) differed from that of CSF (PL > PLP > pyridoxic acid > pyridoxamine). Strong correlations were found for B6 Vitamers in and between plasma and CSF. Treatment with anti-epileptic drugs resulted in decreased concentrations of PL and PLP in CSF. Conclusion We provide concentrations of all B6 Vitamers in plasma and CSF of children with intellectual disability (±epilepsy), which can be used in the investigation of known and novel disorders associated with vitamin B6 metabolism as well as in monitoring of the biochemical effects of treatment with vitamin B6.
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Vitamin B-6 Vitamers in human plasma and cerebrospinal fluid
The American Journal of Clinical Nutrition, 2014Co-Authors: Monique Albersen, Marjolein Bosma, Jurjen J. Luykx, Judith J.m. Jans, Steven C. Bakker, Eric Strengman, P Borgdorff, Peter J M Keijzers, Eric P. A. Van Dongen, Peter BruinsAbstract:Background: Vitamin B-6 comprises a group of 6 interrelated Vitamers and is essential for numerous physiologic processes, including brain functioning. Genetic disorders disrupting vitamin B-6 metabolism have severe clinical consequences. Objective: To adequately diagnose known and novel disorders in vitamin B-6 metabolism, a reference set is required containing information on all vitamin B-6 Vitamers in plasma and cerebrospinal fluid (CSF). Design: Concentrations of B-6 Vitamers in the plasma and CSF of 533 adult subjects were measured by ultra high-performance liquid chromatography‐tandem mass spectrometry. Results: The relative B-6 Vitamer composition of plasma [pyridoxal phosphate (PLP) . pyridoxic acid (PA) . pyridoxal] differed from that of CSF (pyridoxal . PLP . PA . pyridoxamine). Sex influenced B-6 Vitamer concentrations in plasma and CSF and should therefore be taken into account when interpreting B-6 Vitamer concentrations. The strict ratios and strong correlations between B-6 Vitamers point to a tight regulation of B-6 Vitamer concentrations in blood and CSF. Given the unique design of this study, with simultaneously withdrawn blood and CSF from a large number of subjects, reliable CSF:plasma ratios and correlations of B-6 Vitamers could be established. Conclusions: We provide an extensive reference set of B-6 Vitamer concentrations in plasma and CSF. In addition to providing insight on the regulation of individual Vitamers and their intercompartmental distribution, we anticipate that these data will prove to be a valuable reference set for the diagnosis and treatment of conditions associated with altered vitamin B-6 metabolism. Am J Clin Nutr doi: 10.3945/ajcn.113.082008.
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Apical and basolateral amounts of PN, PM and PL in time during incubation with 100 and 1000 nmol/L of either B6 Vitamer.
2013Co-Authors: Monique Albersen, Marjolein Bosma, Tom J. De Koning, Wouter F. Visser, Berna H. B. De Ruiter, Eugène F. Diekman, Jessica De Ruijter, Nine Vvam Knoers, N. M. Verhoeven-duifAbstract:B6 Vitamer concentrations were corrected for compartment volume yielding amounts (pmol). Depicted are means (SE) of triplicates.
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Vitamin B6 Vitamer Concentrations in Cerebrospinal Fluid Differ Between Preterm and Term Newborn Infants
Pediatrics, 2012Co-Authors: Monique Albersen, Marjolein Bosma, M. G. M. De Sain-van Der Velden, Floris Groenendaal, Maria Van Der Ham, Tom J. De Koning, Wouter F. Visser, Gepke Visser, N. M. Verhoeven-duifAbstract:BACKGROUND AND OBJECTIVE: Vitamin B6 plays a pivotal role in brain development and functioning. Differences in vitamin B6 homeostasis between preterm and term newborn infants have been reported. The authors sought to investigate whether B6 Vitamers in cerebrospinal fluid (CSF) of preterm and term newborn infants are different. METHODS: B6 Vitamer concentrations were determined in 69 CSF samples of 36 newborn infants (26 born preterm and 10 born term) by ultra performance liquid chromatography-tandem mass spectrometry. CSF samples, taken from a subcutaneous intraventricular reservoir, were bedside frozen and protected from light. RESULTS: Concentrations of pyridoxal (PL), pyridoxal phosphate (PLP), pyridoxic acid (PA), and pyridoxamine (PM) in preterm newborns (postmenstrual age 30–37 weeks) were at least twice as high as in older newborns (postmenstrual age ≥42 weeks). Pyridoxine and pyridoxamine phosphate concentrations were below limits of quantification in all newborns. In CSF of 2 very preterm newborns (postmenstrual age
Gianfranco Panfili - One of the best experts on this subject based on the ideXlab platform.
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normal phase high performance liquid chromatography method for the determination of tocopherols and tocotrienols in cereals
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Gianfranco Panfili, Alessandra Fratianni, Mario IranoAbstract:The eight Vitamers of vitamin E (α-, β-, γ-, and δ-tocopherols and -tocotrienols) have different antioxidant and biological activities and have different distributions in foods. Some cereals, especially oat, rye, and barley, are good sources of tocotrienols. A fast procedure for the determination of tocopherols and tocotrienols (tocols) in cereal foods was developed. It involves sample saponification and extraction followed by normal phase high-performance liquid chromatography (HPLC). The results have been compared with those found by direct extraction without saponification. The method is sensitive and selective enough to be tested on a wide variety of cereal samples. The highest tocol levels were found in soft wheat and barley (∼75 mg/kg of dry weight). β-Tocotrienol is the main Vitamer found in hulled and dehulled wheats (from 33 to 43 mg/kg of dry weight), γ-tocopherol predominates in maize (45 mg/kg of dry weight) ), and α-tocotrienol predominates in oat and barley (56 and 40 mg/kg of dry weight, re...
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normal phase high performance liquid chromatography method for the determination of tocopherols and tocotrienols in cereals
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Gianfranco Panfili, Alessandra Fratianni, Mario IranoAbstract:The eight Vitamers of vitamin E (alpha-, beta-, gamma-, and delta-tocopherols and -tocotrienols) have different antioxidant and biological activities and have different distributions in foods. Some cereals, especially oat, rye, and barley, are good sources of tocotrienols. A fast procedure for the determination of tocopherols and tocotrienols (tocols) in cereal foods was developed. It involves sample saponification and extraction followed by normal phase high-performance liquid chromatography (HPLC). The results have been compared with those found by direct extraction without saponification. The method is sensitive and selective enough to be tested on a wide variety of cereal samples. The highest tocol levels were found in soft wheat and barley ( approximately 75 mg/kg of dry weight). beta-Tocotrienol is the main Vitamer found in hulled and dehulled wheats (from 33 to 43 mg/kg of dry weight), gamma-tocopherol predominates in maize (45 mg/kg of dry weight) ), and alpha-tocotrienol predominates in oat and barley (56 and 40 mg/kg of dry weight, respectively).
Marjolein Bosma - One of the best experts on this subject based on the ideXlab platform.
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Vitamin B-6 Vitamers in human plasma and cerebrospinal fluid1–4
2016Co-Authors: Monique Albersen, Marjolein Bosma, Jurjen J. Luykx, Judith J.m. Jans, Steven C. Bakker, Eric Strengman, P Borgdorff, Nine Vvam Knoers, Roel A Ophoff, A M Verhoeven-duifAbstract:Background: Vitamin B-6 comprises a group of 6 interrelated vi-tamers and is essential for numerous physiologic processes, includ-ing brain functioning. Genetic disorders disrupting vitamin B-6 metabolism have severe clinical consequences. Objective: To adequately diagnose known and novel disorders in vitamin B-6 metabolism, a reference set is required containing in-formation on all vitamin B-6 Vitamers in plasma and cerebrospinal fluid (CSF). Design: Concentrations of B-6 Vitamers in the plasma and CSF of 533 adult subjects were measured by ultra high-performance liquid chromatography–tandem mass spectrometry. Results: The relative B-6 Vitamer composition of plasma [pyridoxal phosphate (PLP). pyridoxic acid (PA). pyridoxal] differed fro
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vitamin b6 in plasma and cerebrospinal fluid of children
PLOS ONE, 2015Co-Authors: Monique Albersen, Marjolein Bosma, Judith J.m. Jans, Gepke Visser, Floris C Hofstede, Peter M Van Hasselt, Monique G M De Sainvan Der Velden, Nanda M VerhoevenduifAbstract:Background Over the past years, the essential role of vitamin B6 in brain development and functioning has been recognized and genetic metabolic disorders resulting in functional vitamin B6 deficiency have been identified. However, data on B6 Vitamers in children are scarce. Materials and Methods B6 Vitamer concentrations in simultaneously sampled plasma and cerebrospinal fluid (CSF) of 70 children with intellectual disability were determined by ultra performance liquid chro-matography-tandem mass spectrometry. For ethical reasons, CSF samples could not be obtained from healthy children. The influence of sex, age, epilepsy and treatment with antiepileptic drugs, were investigated. Results The B6 Vitamer composition of plasma (pyridoxal phosphate (PLP) > pyridoxic acid > pyridoxal (PL)) differed from that of CSF (PL > PLP > pyridoxic acid > pyridoxamine). Strong correlations were found for B6 Vitamers in and between plasma and CSF. Treatment with anti-epileptic drugs resulted in decreased concentrations of PL and PLP in CSF. Conclusion We provide concentrations of all B6 Vitamers in plasma and CSF of children with intellectual disability (±epilepsy), which can be used in the investigation of known and novel disorders associated with vitamin B6 metabolism as well as in monitoring of the biochemical effects of treatment with vitamin B6.
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Vitamin B-6 Vitamers in human plasma and cerebrospinal fluid
The American Journal of Clinical Nutrition, 2014Co-Authors: Monique Albersen, Marjolein Bosma, Jurjen J. Luykx, Judith J.m. Jans, Steven C. Bakker, Eric Strengman, P Borgdorff, Peter J M Keijzers, Eric P. A. Van Dongen, Peter BruinsAbstract:Background: Vitamin B-6 comprises a group of 6 interrelated Vitamers and is essential for numerous physiologic processes, including brain functioning. Genetic disorders disrupting vitamin B-6 metabolism have severe clinical consequences. Objective: To adequately diagnose known and novel disorders in vitamin B-6 metabolism, a reference set is required containing information on all vitamin B-6 Vitamers in plasma and cerebrospinal fluid (CSF). Design: Concentrations of B-6 Vitamers in the plasma and CSF of 533 adult subjects were measured by ultra high-performance liquid chromatography‐tandem mass spectrometry. Results: The relative B-6 Vitamer composition of plasma [pyridoxal phosphate (PLP) . pyridoxic acid (PA) . pyridoxal] differed from that of CSF (pyridoxal . PLP . PA . pyridoxamine). Sex influenced B-6 Vitamer concentrations in plasma and CSF and should therefore be taken into account when interpreting B-6 Vitamer concentrations. The strict ratios and strong correlations between B-6 Vitamers point to a tight regulation of B-6 Vitamer concentrations in blood and CSF. Given the unique design of this study, with simultaneously withdrawn blood and CSF from a large number of subjects, reliable CSF:plasma ratios and correlations of B-6 Vitamers could be established. Conclusions: We provide an extensive reference set of B-6 Vitamer concentrations in plasma and CSF. In addition to providing insight on the regulation of individual Vitamers and their intercompartmental distribution, we anticipate that these data will prove to be a valuable reference set for the diagnosis and treatment of conditions associated with altered vitamin B-6 metabolism. Am J Clin Nutr doi: 10.3945/ajcn.113.082008.
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Apical and basolateral amounts of PN, PM and PL in time during incubation with 100 and 1000 nmol/L of either B6 Vitamer.
2013Co-Authors: Monique Albersen, Marjolein Bosma, Tom J. De Koning, Wouter F. Visser, Berna H. B. De Ruiter, Eugène F. Diekman, Jessica De Ruijter, Nine Vvam Knoers, N. M. Verhoeven-duifAbstract:B6 Vitamer concentrations were corrected for compartment volume yielding amounts (pmol). Depicted are means (SE) of triplicates.
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Vitamin B6 Vitamer Concentrations in Cerebrospinal Fluid Differ Between Preterm and Term Newborn Infants
Pediatrics, 2012Co-Authors: Monique Albersen, Marjolein Bosma, M. G. M. De Sain-van Der Velden, Floris Groenendaal, Maria Van Der Ham, Tom J. De Koning, Wouter F. Visser, Gepke Visser, N. M. Verhoeven-duifAbstract:BACKGROUND AND OBJECTIVE: Vitamin B6 plays a pivotal role in brain development and functioning. Differences in vitamin B6 homeostasis between preterm and term newborn infants have been reported. The authors sought to investigate whether B6 Vitamers in cerebrospinal fluid (CSF) of preterm and term newborn infants are different. METHODS: B6 Vitamer concentrations were determined in 69 CSF samples of 36 newborn infants (26 born preterm and 10 born term) by ultra performance liquid chromatography-tandem mass spectrometry. CSF samples, taken from a subcutaneous intraventricular reservoir, were bedside frozen and protected from light. RESULTS: Concentrations of pyridoxal (PL), pyridoxal phosphate (PLP), pyridoxic acid (PA), and pyridoxamine (PM) in preterm newborns (postmenstrual age 30–37 weeks) were at least twice as high as in older newborns (postmenstrual age ≥42 weeks). Pyridoxine and pyridoxamine phosphate concentrations were below limits of quantification in all newborns. In CSF of 2 very preterm newborns (postmenstrual age
