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Ling Sun Jen - One of the best experts on this subject based on the ideXlab platform.

  • expression of β amyloid precursor and bcl 2 proto oncogene proteins in rat retinas after intravitreal injection of aminoadipic Acid
    Neurochemistry International, 1999
    Co-Authors: Shur-tzu Chen, Jiang-ping Wang, L.j. Garey, Ling Sun Jen
    Abstract:

    In order to investigate the role of glia in relation to factors that affect the expression of beta-amyloid precursor protein (betaAPP) and B cell lymphoma oncogene protein (Bcl-2) in the central nervous tissue, the patterns of expression of betaAPP and Bcl-2 in developing and mature rat retinas were studied immunocytochemically after intravitreal injection of Alpha-Aminoadipic Acid (alpha-AAA), a glutamate analogue and gliotoxin that is known to cause injury of retinal Muller glial cells. In normal developing retinas, betaAPP and Bcl-2 were expressed primarily but transiently in a small number of neurons in the ganglion cell layer during the first postnatal week. Immunoreactivity of betaAPP and Bcl-2 appeared in the endfeet and proximal part of the radial processes of Muller glial cells from the second postnatal week onwards. In rats that received intravitreal injection of alpha-AAA at birth, there was a loss of immunoreactivity to vimentin, and a delayed expressed on betaAPP or Bcl-2 in Muller glial cells until 3-5 weeks post-injection. Immunoreactive neurons were also observed in the inner retina especially in the ganglion cell layer from 5 to 35 days after injection. A significant reduction in numerical density of cells with large somata in the ganglion cell layer was observed in the neonatally injected retinas at P56, which was accompanied by an increased immunostaining in radial processes of Muller glial cells. In contrast, no detectable changes in the expression of betaAPP and Bcl-2 were observed in retina that received alpha-AAA as adults. These results indicate that the gliotoxin alpha-AAA has long lasting effects on the expression of betaAPP and Bcl-2 in Muller glial cells as well as neurons in the developing but not mature retinas. The loss of vimentin and delayed expression of betaAPP and Bcl-2 in developing Muller glial cells suggests that the metabolic integrity of Muller cells was temporarily compromised, which may have adverse effects on developing neurons that are vulnerable or dependent on trophic support from the Muller glial cells.

  • Expression of β-amyloid precursor and Bcl-2 proto-oncogene proteins in rat retinas after intravitreal injection of aminoadipic Acid
    Neurochemistry international, 1999
    Co-Authors: Shur-tzu Chen, Jiang-ping Wang, L.j. Garey, Ling Sun Jen
    Abstract:

    Abstract In order to investigate the role of glia in relation to factors that affect the expression of beta-amyloid precursor protein ( β APP) and B cell lymphoma oncogene protein (Bcl-2) in the central nervous tissue, the patterns of expression of β APP and Bcl-2 in developing and mature rat retinas were studied immunocytochemically after intravitreal injection of Alpha-Aminoadipic Acid ( α -AAA), a glutamate analogue and gliotoxin that is known to cause injury of retinal Muller glial cells. In normal developing retinas, β APP and Bcl-2 were expressed primarily but transiently in a small number of neurons in the ganglion cell layer during the first postnatal week. Immunoreactivity of β APP and Bcl-2 appeared in the endfeet and proximal part of the radial processes of Muller glial cells from the second postnatal week onwards. In rats that received intravitreal injection of α -AAA at birth, there was a loss of immunoreactivity to vimentin, and a delayed expressed on β APP or Bcl-2 in Muller glial cells until 3–5 weeks post-injection. Immunoreactive neurons were also observed in the inner retina especially in the ganglion cell layer from 5 to 35 days after injection. A significant reduction in numerical density of cells with large somata in the ganglion cell layer was observed in the neonatally injected retinas at P56, which was accompanied by an increased immunostaining in radial processes of Muller glial cells. In contrast, no detectable changes in the expression of β APP and Bcl-2 were observed in retina that received α -AAA as adults. These results indicate that the gliotoxin α -AAA has long lasting effects on the expression of β APP and Bcl-2 in Muller glial cells as well as neurons in the developing but not mature retinas. The loss of vimentin and delayed expression of β APP and Bcl-2 in developing Muller glial cells suggests that the metabolic integrity of Muller cells was temporarily compromised, which may have adverse effects on developing neurons that are vulnerable or dependent on trophic support from the Muller glial cells.

Tatiana Yuzyuk - One of the best experts on this subject based on the ideXlab platform.

  • the effects of a single oral dose of pyridoxine on alpha aminoadipic semialdehyde piperideine 6 carboxylate pipecolic Acid and alpha aminoadipic Acid levels in pyridoxine dependent epilepsy
    Frontiers in Pediatrics, 2019
    Co-Authors: Junjuan Wang, Yuehua Zhang, Yuwu Jiang, Jiao Xue, Pan Gong, Tatiana Yuzyuk, Wenshuang Yang, Shiju Jiang, Zhixian Yang
    Abstract:

    Purpose: To evaluate the effects of a single oral dose of pyridoxine on lysine metabolites including α-aminoadipic semialdehyde (a-AASA), piperideine-6-carboxylate (P6C), the sum of AASA and P6C (AASA-P6C), pipecolic Acid (PA), and α-aminoadipic Acid (α-AAA) in PDE patients. Methods: The lysine metabolites of 15 patients with molecularly confirmed PDE were detected before and 4 h after taking a single oral dose of pyridoxine, respectively, using liquid chromatography-mass spectrometry (LC-MS/MS) method. Five types of samples were freshly prepared, including plasma, serum, dried blood spots (DBS), urine, and dried urine spots (DUS). Results: All the patients had been treated with long-term oral pyridoxine for several months to years, with doses of 30-360 mg/d. The concentrations of a-AASA, P6C, AASA-P6C, PA, and a-AAA before and after taking a single oral dose of pyridoxine for the same analyte detected in the same type of sample varied among patients. The mean concentrations increased in almost all the metabolites after taking an oral dose of pyridoxine, with or without statistical significance. Whereas, the metabolites concentrations might increase or decrease among different patients, or in different samples of the same patient, without a regular tendency. There was no statistical correlation between the concentrations before and after taking pyridoxine in the same type of sample for most metabolites. Conclusions: No obvious relationship between the metabolite levels or concentration differences and the age, pyridoxine dose (a single oral dose and long-term maintenance dose), duration of treatment, or neurodevelopmental phenotype was found at present study. The large individual differences among patients, probably affected by various genotypes, leading to quite different effects of pyridoxine on the change degree of metabolites concentrations. Our study suggested that long-term pyridoxine treatment could control seizures rather than getting toxic lysine metabolites such as a-AASA and P6C back to normal. In the future, more therapies should be focused to alleviate the metabolites accumulation and further improve the prognosis of PDE.

  • Simultaneous quantification of Alpha-Aminoadipic semialdehyde, piperideine-6-carboxylate, pipecolic Acid and Alpha-Aminoadipic Acid in pyridoxine-dependent epilepsy.
    Scientific reports, 2019
    Co-Authors: Jiao Xue, Yuehua Zhang, Yuwu Jiang, Pan Gong, Junjuan Wang, Wenshuang Yang, Shiju Jiang, Tatiana Yuzyuk
    Abstract:

    The measurements of lysine metabolites provide valuable information for the rapid diagnosis of pyridoxine-dependent epilepsy (PDE). Here, we aimed to develop a sensitive method to simultaneously quantify multiple lysine metabolites in PDE, including α-aminoadipic semialdehyde (a-AASA), piperideine-6-carboxylate (P6C), pipecolic Acid (PA) and α-aminoadipic Acid (α-AAA) in plasma, serum, dried blood spots (DBS), urine and dried urine spots (DUS). Fifteen patients with molecularly confirmed PDE were detected using liquid chromatography-mass spectrometry (LC-MS/MS) method. Compared to the control groups, the concentrations of a-AASA, P6C and the sum of a-AASA and P6C (AASA-P6C) in all types of samples from PDE patients were markedly elevated. The PA and a-AAA concentrations ranges overlapped partially between PDE patients and control groups. The concentrations of all the analytes in plasma and serum, as well as in urine and DUS were highly correlated. Our study provided more options for the diverse sample collection in the biochemical tests according to practical requirements. With treatment modality of newly triple therapy investigated, biomarker study might play important role not only on diagnosis but also on treatment monitoring and fine tuning the diet. The persistently elevated analytes with good correlation between plasma and DBS, as well as urine and DUS made neonatal screening using DBS and DUS possible.

Vincent M Monnier - One of the best experts on this subject based on the ideXlab platform.

  • aging diabetes and renal failure catalyze the oxidation of lysyl residues to 2 aminoadipic Acid in human skin collagen
    Annals of the New York Academy of Sciences, 2008
    Co-Authors: David R Sell, Christopher Strauch, Wei Shen, Vincent M Monnier
    Abstract:

    The epsilon-amino group of lysyl residues oxidatively deaminates in the presence of alpha-dicarbonyl sugars and redox-active metals forming Alpha-Aminoadipic Acid-delta-semialdehyde (allysine; Suyama's hypothesis), which can further oxidize into 2-aminoadipic Acid. Here we show that 2-aminoadipic Acid is significantly (P 2 nmol/mg collagen).

  • 2 aminoadipic Acid is a marker of protein carbonyl oxidation in the aging human skin effects of diabetes renal failure and sepsis
    Biochemical Journal, 2007
    Co-Authors: David R Sell, Christopher Strauch, Wei Shen, Vincent M Monnier
    Abstract:

    We hypothesized that the epsilon-amino group of lysine residues in longlived proteins oxidatively deaminates with age forming the carbonyl compound, allysine (Alpha-Aminoadipic Acid-delta-semialdehyde), which can further oxidize into 2-aminoadipic Acid. In the present study, we measured both products in insoluble human skin collagen from n=117 individuals of age range 10-90 years, of which n=61 and n=56 were non-diabetic and diabetic respectively, and a total of n=61 individuals had either acute or chronic renal failure. Allysine was reduced by borohydride into 6-hydroxynorleucine and both products were measured in Acid hydrolysates by selective ion monitoring gas chromatography (GC)-MS. The results showed that 2-aminoadipic Acid (P<0.0001), but not 6-hydroxynorleucine (P=0.14), significantly increased with age reaching levels of 1 and 0.3 mmol/mol lysine at late age respectively. Diabetes in the absence of renal failure significantly (P<0.0001) increased 2-aminoadipic Acid up to <3 mmol/mol, but not 6-hydroxynorleucine (levels<0.4 mmol/mol, P=0.18). Renal failure even in the absence of diabetes markedly increased levels reaching up to <0.5 and 8 mmol/mol for 6-hydroxynorleucine and 2-aminoadipic Acid respectively. Septicaemia significantly (P<0.0001) elevated 2-aminoadipic Acid in non-diabetic, but not diabetic individuals, and mildly correlated with other glycoxidation markers, carboxymethyl-lysine and the methylglyoxal-derived products, carboxyethyl-lysine, argpyrimidine and MODIC (methylglyoxal-derived imidazolium cross-link). These results provide support for the presence of metal-catalysed oxidation (the Suyama pathway) in diabetes and the possible activation of myeloperoxidase during sepsis. We conclude that 2-aminoadipic Acid is a more reliable marker for protein oxidation than its precursor, allysine. Its mechanism of formation in each of these conditions needs to be elucidated.

Shur-tzu Chen - One of the best experts on this subject based on the ideXlab platform.

  • expression of β amyloid precursor and bcl 2 proto oncogene proteins in rat retinas after intravitreal injection of aminoadipic Acid
    Neurochemistry International, 1999
    Co-Authors: Shur-tzu Chen, Jiang-ping Wang, L.j. Garey, Ling Sun Jen
    Abstract:

    In order to investigate the role of glia in relation to factors that affect the expression of beta-amyloid precursor protein (betaAPP) and B cell lymphoma oncogene protein (Bcl-2) in the central nervous tissue, the patterns of expression of betaAPP and Bcl-2 in developing and mature rat retinas were studied immunocytochemically after intravitreal injection of Alpha-Aminoadipic Acid (alpha-AAA), a glutamate analogue and gliotoxin that is known to cause injury of retinal Muller glial cells. In normal developing retinas, betaAPP and Bcl-2 were expressed primarily but transiently in a small number of neurons in the ganglion cell layer during the first postnatal week. Immunoreactivity of betaAPP and Bcl-2 appeared in the endfeet and proximal part of the radial processes of Muller glial cells from the second postnatal week onwards. In rats that received intravitreal injection of alpha-AAA at birth, there was a loss of immunoreactivity to vimentin, and a delayed expressed on betaAPP or Bcl-2 in Muller glial cells until 3-5 weeks post-injection. Immunoreactive neurons were also observed in the inner retina especially in the ganglion cell layer from 5 to 35 days after injection. A significant reduction in numerical density of cells with large somata in the ganglion cell layer was observed in the neonatally injected retinas at P56, which was accompanied by an increased immunostaining in radial processes of Muller glial cells. In contrast, no detectable changes in the expression of betaAPP and Bcl-2 were observed in retina that received alpha-AAA as adults. These results indicate that the gliotoxin alpha-AAA has long lasting effects on the expression of betaAPP and Bcl-2 in Muller glial cells as well as neurons in the developing but not mature retinas. The loss of vimentin and delayed expression of betaAPP and Bcl-2 in developing Muller glial cells suggests that the metabolic integrity of Muller cells was temporarily compromised, which may have adverse effects on developing neurons that are vulnerable or dependent on trophic support from the Muller glial cells.

  • Expression of β-amyloid precursor and Bcl-2 proto-oncogene proteins in rat retinas after intravitreal injection of aminoadipic Acid
    Neurochemistry international, 1999
    Co-Authors: Shur-tzu Chen, Jiang-ping Wang, L.j. Garey, Ling Sun Jen
    Abstract:

    Abstract In order to investigate the role of glia in relation to factors that affect the expression of beta-amyloid precursor protein ( β APP) and B cell lymphoma oncogene protein (Bcl-2) in the central nervous tissue, the patterns of expression of β APP and Bcl-2 in developing and mature rat retinas were studied immunocytochemically after intravitreal injection of Alpha-Aminoadipic Acid ( α -AAA), a glutamate analogue and gliotoxin that is known to cause injury of retinal Muller glial cells. In normal developing retinas, β APP and Bcl-2 were expressed primarily but transiently in a small number of neurons in the ganglion cell layer during the first postnatal week. Immunoreactivity of β APP and Bcl-2 appeared in the endfeet and proximal part of the radial processes of Muller glial cells from the second postnatal week onwards. In rats that received intravitreal injection of α -AAA at birth, there was a loss of immunoreactivity to vimentin, and a delayed expressed on β APP or Bcl-2 in Muller glial cells until 3–5 weeks post-injection. Immunoreactive neurons were also observed in the inner retina especially in the ganglion cell layer from 5 to 35 days after injection. A significant reduction in numerical density of cells with large somata in the ganglion cell layer was observed in the neonatally injected retinas at P56, which was accompanied by an increased immunostaining in radial processes of Muller glial cells. In contrast, no detectable changes in the expression of β APP and Bcl-2 were observed in retina that received α -AAA as adults. These results indicate that the gliotoxin α -AAA has long lasting effects on the expression of β APP and Bcl-2 in Muller glial cells as well as neurons in the developing but not mature retinas. The loss of vimentin and delayed expression of β APP and Bcl-2 in developing Muller glial cells suggests that the metabolic integrity of Muller cells was temporarily compromised, which may have adverse effects on developing neurons that are vulnerable or dependent on trophic support from the Muller glial cells.

Jiao Xue - One of the best experts on this subject based on the ideXlab platform.

  • the effects of a single oral dose of pyridoxine on alpha aminoadipic semialdehyde piperideine 6 carboxylate pipecolic Acid and alpha aminoadipic Acid levels in pyridoxine dependent epilepsy
    Frontiers in Pediatrics, 2019
    Co-Authors: Junjuan Wang, Yuehua Zhang, Yuwu Jiang, Jiao Xue, Pan Gong, Tatiana Yuzyuk, Wenshuang Yang, Shiju Jiang, Zhixian Yang
    Abstract:

    Purpose: To evaluate the effects of a single oral dose of pyridoxine on lysine metabolites including α-aminoadipic semialdehyde (a-AASA), piperideine-6-carboxylate (P6C), the sum of AASA and P6C (AASA-P6C), pipecolic Acid (PA), and α-aminoadipic Acid (α-AAA) in PDE patients. Methods: The lysine metabolites of 15 patients with molecularly confirmed PDE were detected before and 4 h after taking a single oral dose of pyridoxine, respectively, using liquid chromatography-mass spectrometry (LC-MS/MS) method. Five types of samples were freshly prepared, including plasma, serum, dried blood spots (DBS), urine, and dried urine spots (DUS). Results: All the patients had been treated with long-term oral pyridoxine for several months to years, with doses of 30-360 mg/d. The concentrations of a-AASA, P6C, AASA-P6C, PA, and a-AAA before and after taking a single oral dose of pyridoxine for the same analyte detected in the same type of sample varied among patients. The mean concentrations increased in almost all the metabolites after taking an oral dose of pyridoxine, with or without statistical significance. Whereas, the metabolites concentrations might increase or decrease among different patients, or in different samples of the same patient, without a regular tendency. There was no statistical correlation between the concentrations before and after taking pyridoxine in the same type of sample for most metabolites. Conclusions: No obvious relationship between the metabolite levels or concentration differences and the age, pyridoxine dose (a single oral dose and long-term maintenance dose), duration of treatment, or neurodevelopmental phenotype was found at present study. The large individual differences among patients, probably affected by various genotypes, leading to quite different effects of pyridoxine on the change degree of metabolites concentrations. Our study suggested that long-term pyridoxine treatment could control seizures rather than getting toxic lysine metabolites such as a-AASA and P6C back to normal. In the future, more therapies should be focused to alleviate the metabolites accumulation and further improve the prognosis of PDE.

  • Simultaneous quantification of Alpha-Aminoadipic semialdehyde, piperideine-6-carboxylate, pipecolic Acid and Alpha-Aminoadipic Acid in pyridoxine-dependent epilepsy.
    Scientific reports, 2019
    Co-Authors: Jiao Xue, Yuehua Zhang, Yuwu Jiang, Pan Gong, Junjuan Wang, Wenshuang Yang, Shiju Jiang, Tatiana Yuzyuk
    Abstract:

    The measurements of lysine metabolites provide valuable information for the rapid diagnosis of pyridoxine-dependent epilepsy (PDE). Here, we aimed to develop a sensitive method to simultaneously quantify multiple lysine metabolites in PDE, including α-aminoadipic semialdehyde (a-AASA), piperideine-6-carboxylate (P6C), pipecolic Acid (PA) and α-aminoadipic Acid (α-AAA) in plasma, serum, dried blood spots (DBS), urine and dried urine spots (DUS). Fifteen patients with molecularly confirmed PDE were detected using liquid chromatography-mass spectrometry (LC-MS/MS) method. Compared to the control groups, the concentrations of a-AASA, P6C and the sum of a-AASA and P6C (AASA-P6C) in all types of samples from PDE patients were markedly elevated. The PA and a-AAA concentrations ranges overlapped partially between PDE patients and control groups. The concentrations of all the analytes in plasma and serum, as well as in urine and DUS were highly correlated. Our study provided more options for the diverse sample collection in the biochemical tests according to practical requirements. With treatment modality of newly triple therapy investigated, biomarker study might play important role not only on diagnosis but also on treatment monitoring and fine tuning the diet. The persistently elevated analytes with good correlation between plasma and DBS, as well as urine and DUS made neonatal screening using DBS and DUS possible.